CD3268A TI | Alldatasheet
Document overview
- Manufacturer or author: Provided By alldatasheet.com(free datasheet download site)
- PDF pages: 35
Technical content
CD326x Audio Interface Transmitter for Specially Enabled Headsets
1 Features
- Compatible with specially enabled audio interfaces (iPhone® and iPad®)
- Low quiescent current – Button mode (microphone not in use): 3µA – Tone mode (microphone in use): 110µA
- Miniature DSBGA (YZP) package
- ESD performance – Human body model: 2000V – Charged device model: 500V
2 Applications
- Wired headset signaling transmitter compatible with systems including a specially enabled audio interface
- See Chapter 54: Headset Remote and Microphone Transmitter in Accessory Design Guidelines for Apple Devices from the Apple Development Page
3 Description
The CD326x supports two operating modes; button mode and tone mode. Button mode offers no microphone support. Button mode passes the DC voltage from an external switch-resistor network (tied to the REM pin) to the MIC pin to measure the voltage externally. Tone mode offers microphone support and senses button presses based on an external switch-resistor network (tied to the REM pin). Tone mode generates corresponding ultrasonic signals that are superimposed (via a driver output on the TONE pin) on the system MICBIAS line. These signals control audio functions when connected to a specially enabled audio interface. The input DC bias level provided on the MIC pin controls button or tone mode selection. During tone mode, the CD326x also provides functionality to control or bias an external MEMS (micro-electrical-mechanical systems) technology microphone module.
Package Information
PART NUMBER PACKAGE(1) PACKAGE SIZE(2) CD3268 YZP (DSBGA, 6) 1.45mm × 0.95mm × 0.5mm CD3269 YZP (DSBGA, 6) 1.45mm × 0.95mm × 0.5mm (1) For all available packages, see the orderable addendum in Section 11 (2) The package size (length × width × height) is a nominal value and includes pins, where applicable Device Information PART NUMBER TX ACK TONE FREQUENCY (kHz) (TYP) EQUIVALENT BUTTON CD3268 130 1 CD3269 165 2 VSHUNT MIC TONE MICPWR GND REM CD326x RTONECTONE RVSHUNTCVSHUNT R2 R3 R4 S2 S3 S4 Microphone module VMIC Host system (including specially-enabled audio interface) INT MICBIAS GND Simplified Application CD3268A, CD3269A SCHS463 – MAY 2025 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA.
11 Mechanical, Packaging, and Orderable
CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
2 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
4 Pin Configuration and Functions
C B A VSHUNT MICPWR MIC REM TONE GND 1 2 Figure 4-1. DSBGA Package, 6-Pin YZP (Top View) Table 4-1. Pin Functions PIN TYPE(1) DESCRIPTION NAME NO. GND A2 P Ground MIC B1 I Input DC bias; voltage determines the mode of operation. MICPWR C2 O Microphone power; used as a control output to enable/disable an external microphone module. REM B2 I/O Remote switch network TONE A1 O Tone generator output VSHUNT C1 I External microphone bias (1) I = Input, O = Output, I/O = Input or Output, P = Power www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 3 Product Folder Links: CD3268A CD3269A
5 Specifications
5.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1) MIN MAX UNIT VSUPPLY Supply voltage, VSHUNT, MIC pins -0.5 4.6 V V0 Output voltage, MICPWR, TONE pins -0.5 4.6 V I0K Output clamp current, MICPWR, TONE pins (V0 < 0) -20 mA VI Input voltage, REM pin -0.5 4.6 V IIK Input clamp current, REM pin (VI < 0) -20 mA ISUPPLY & IGND Continuous current through VSHUNT, MIC, or GND pins -50 50 mA Tstg Storage temperature –65 150 °C (1) Operation outside the Absolute Maximum Ratings may cause permanent device damage. Absolute Maximum Ratings do not imply functional operation of the device at these or any other conditions beyond those listed under Recommended Operating Conditions. If used outside the Recommended Operating Conditions but within the Absolute Maximum Ratings, the device may not be fully functional, and this may affect device reliability, functionality, performance, and shorten the device lifetime.
5.2 ESD Ratings
V(ESD) Electrostatic discharge Human Body Model ±2000 V Charged-Device Model ±500
5.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted) MIN NOM MAX UNIT VMICBIAS Button Mode - Bias Voltage (MIC pin is connected to MICBIAS through a 1% 2.21kΩ resistor); MIC pin voltages in this range enable Button Mode 1.8 2.1 V VMICBIAS Tone Mode - Bias Voltage (MIC pin is connected to MICBIAS through a 1% 2.21kΩ resistor); MIC pin voltages in this range enable Tone Mode 2.56 2.84 V TA Ambient temperature –40 85 °C
5.4 Thermal Information
THERMAL METRIC(1) YZP (DSBGA) UNIT
6 PINS
RθJA Junction-to-ambient thermal resistance - YZP Package 123 °C/W (1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application note.
5.5 Electrical Characteristics
over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Biases, Currents, & Thresholds IMICBIAS-B Quiescent Current into MIC + VSHUNT Button Mode, VMICBIAS = 2.1V, (Figure 6-2) 3 6 μA IMIC-T Quiescent Current into MIC Tone Mode, (Figure 6-3) 34 46 μA IVSHUNT-T Quiescent Current into VSHUNT Tone Mode(1), (Figure 6-3) 60 80 μA IMIC-TA Active Current into MIC Tone Mode, (Figure 6-4) 35 45 μA CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
4 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
5.5 Electrical Characteristics (continued)
over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT IVSHUNT- TA Active Current into VSHUNT Tone Mode(1), (Figure 6-4) 104 123 μA VTR Tone Mode Threshold Voltage - Rising MIC Rising (microphone enable), VMICPWR = 1.0V, (Figure 6-6 and Figure 6-7) 2.20 2.35 2.5 V VTF Tone Mode Threshold Voltage - Falling MIC Falling (microphone enable), VMICPWR = 0.4V, (Figure 6-6 and Figure 6-7) 0.55 0.8 1 V VMICPWR MICPWR Output Voltage IMICPWR = 120μA to 150μA, (Figure 6-5) 1.51 1.56 1.61 V RSO Shunt Regulator Output Impedance Freq = 100Hz, (Figure 6-8) 5 18 25 Ω Freq = 20kHz, (Figure 6-8) 12 21 35 Ω Freq = 300kHz, (Figure 6-8) 300 458 650 Ω Freq = 1MHz, (Figure 6-8) 2600 2830 3300 Ω RONA Switch A, RDSON Tone Mode, IMICPWR = 1mA, VMICBIAS = 2.56V, (Figure 6-9) 40 55 Ω RONB Switch B, RDSON Button Mode, IREM = 1mA, VMIC = 1.2V, (Figure 6-10) 22 30.5 Ω Tone and Button Mode Parameters en-mic100 MIC Integrated Noise 100Hz to 20kHz, (Figure 6-1) 1.5 2 μVRMS en-mic1K MIC Integrated Noise 1kHz to 20kHz, (Figure 6-1) 0.39 1 μVRMS fTONE1 Button 1 Frequency - CD3268 ACK Tone RREM = 6.81kΩ, (Figure 6-13) 109 130 159 kHz fTONE2 Button 2 Frequency - CD3269 ACK Tone RREM = 9.42kΩ, (Figure 6-13) 138 165 200 kHz fTONE3 Button 3 Frequency RREM = 12.99kΩ, (Figure 6-13) 167 201 242 kHz fTONE4 Button 4 Frequency RREM = 19.8 kΩ, (Figure 6-13) 196 237 284 kHz fCAL Calibration Frequency (Figure 6-13) 225 271 325 kHz fREL Button Release Frequency (Figure 6-13) 81 97 117 kHz BR1 Button 1 Ratio fTONE1 / fCAL 0.470 0.488 0.500 BR2 Button 2 Ratio fTONE2 / fCAL 0.600 0.609 0.630 BR3 Button 3 Ratio fTONE3 / fCAL 0.730 0.740 0.758 BR4 Button 4 Ratio fTONE4 / fCAL 0.860 0.876 0.890 BRREL Button Release Ratio fREL / fCAL 0.340 0.360 0.380 RBT1 Button 1 Boundary 6.61 6.81 7.01 kΩ RBT2 Button 2 Boundary 9.14 9.42 9.7 kΩ RBT3 Button 3 Boundary 12.60 12.99 13.38 kΩ RBT4 Button 4 Boundary 19.21 19.80 20.39 kΩ VTA Tone Amplitude RTONE = 1MΩ, (Figure 6-11 and Figure 6-12) 350 550 720 mVp-p RTONE = 100kΩ, (Figure 6-11 and Figure 6-12) 300 515 710 mVp-p RTONE = 10kΩ, (Figure 6-11 and Figure 6-12) 200 390 620 mVp-p RTONE = 1kΩ, (Figure 6-11 and Figure 6-12) 40 140 320 mVp-p (1) This current is pulled through RVSHUNT between MIC and VSHUNT and is the minimum current to keep VSHUNT regulated at 1.56V. Excess current through RVSHUNT will be available to the load at MICPWR. Excess current not used by the load at MICPWR will be internally shunted to GND. www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 5 Product Folder Links: CD3268A CD3269A
5.6 Timing Requirements
over operating free-air temperature range (unless otherwise noted) PARAMETER DEFINITION MIN TYP MAX UNIT Tone, Button, and Switch Timing tCAL Calibration Tone Duration, (Figure 7-2) 0.8 0.9 0.98 ms tACK ACK Tone Duration, (Figure 7-2) 5.0 5.5 6.0 ms tB Button Tone Duration 1.4 1.8 2.2 ms tDB Button Debounce Time 8.4 9.1 10 ms tM2T Tone Send Delay after Tone Mode Enable, (Figure 7-2) 4 6 8 ms tONA Switch A Enable Time, (Figure 7-2) 0.8 1.2 2 ms tOFFB Switch B Disable Time, (Figure 7-2) 0.7 1 2 ms tREG Shunt Regulator Enable Time: time from MIC = 2.3V to MICPWR = 1.56V, (Figure 7-2) 1 2.5 3.5 ms CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
6 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
6 Parameter Measurement Information
This section shows design schematics for select performance measurements. 6.1 eN-MIC Microphone Integrated Noise Measurement VSHUNT MIC TONE MICPWR GND REM CD326x 20k VMICBIAS 2.84V 100nF Meter 200pF 2.21k 100nF VMIC must rise above 2.35V (typ) to enter tone mode before measurement. Figure 6-1. Test Set-up for MIC Integrated Noise
6.2 Current Measurements
2.1V 100nF 2.21k IMICBIAS Figure 6-2. Test Set-up for Button Mode Current Measurement www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 7 Product Folder Links: CD3268A CD3269A
2.84V 100nF 2.21k VS2 1.45V VMIC must rise above 2.35V (typ) to enter tone mode before measurement is taken. I M IC − T = I MICBIAS − V M IC − 1.45 1.0k I VSHUN T − T = V M IC − 1.45 1.0k − I VS2 Figure 6-3. Tone Mode Quiescent Current Consumption Measurement VSHUNT MIC TONE MICPWR GND REM CD326x VMICBIAS 2.84V 100nF 2.21k VS2 1.45V 20k 300pF 6.81k VMIC must rise above 2.35V (typ) to enter tone mode before VS2 is applied. Current measurements are taken during calibration tone. I M IC − T = I MICBIAS − V M IC − 1.45 1.0k I VSHUN T − T = V M IC − 1.45 1.0k − I VS2 Figure 6-4. Tone Mode Active Current Consumption Measurement CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
8 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
6.3 MICPWR Output Voltage Measurement
2.56V 100nF 2.21k VSMICPWR2 150µA VMIC must rise above 2.35V (typ) to enter tone mode before measurement is taken. Figure 6-5. VMICPWR Measurement
6.4 Tone Mode Threshold Measurements
VMIC must rise above 2.35V (typ) to enter tone mode before measurement is taken. Figure 6-6. VTR and VTF Measurement www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 9 Product Folder Links: CD3268A CD3269A
MIC pin voltage (V) 1.56 VTF 2.5 VTR 1.0 0.4 MICPWR pin voltage (V) Figure 6-7. VTR and VTF Waveforms
6.5 Impedance Measurements
2.21k 100 VBVA 100mVP-P 100µF VMIC must rise above 2.35V (typ) to enter tone mode before measurement is taken. R SO = V B V A − V B / 100 Figure 6-8. RSO Shunt Regulator Impedance Measurement CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
10 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
6.6 Tone Mode Output Measurements
2.21k RTONE VMIC must rise above 2.35V (typ) to enter tone mode before measurement is taken. Tone amplitude is measured during Cal Tone Figure 6-11. VTA Tone Amplitude Measurement MIC pin voltage (V) 2.35V 2.5V 2.5V VTA TONE pin voltage (V) Figure 6-12. VTA Waveforms CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
12 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
2.21k RREM probe VTONE VMIC must rise above 2.35V (typ) to enter tone mode before measurement is taken. Figure 6-13. fTONE Tone Frequency Measurement www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 13 Product Folder Links: CD3268A CD3269A
7 Detailed Description
7.1 Overview
The CD326x communicates with a specially enabled audio interface to report detected remote button presses. Two basic modes are supported—button mode and tone mode—and the active mode is determined by the DC bias voltage level on the MIC pin (2.5V and 2.0V for tone mode and button mode respectively). The bias voltage is typically provided by a specially enabled audio interface. During button mode operation, the CD326x operates as a pass-through element that connects the DC voltage on the REM pin to the MIC pin. The REM pin is connected to an external switch-resistor network where each switch represents a unique button. When a button is pressed, the DC level on the bias line is changed before being externally detected and measured by a specially enabled audio interface. Button mode does not support bias or control of an external microphone. In Figure 7-1, button mode is represented by switch A being open and switch B being closed. During tone mode operation, the CD326x supports the use of an external MEMS microphone module. The module can be biased from the MICPWR pin or the MICPWR pin can be used to control an external circuit to enable or disable power to the microphone as shown in Figure 8-1 . The REM pin is used to detect button presses from an external switch-resistor network, and the CD326x then generates a corresponding, ultrasonic signal on the TONE pin. The tones are unique to each button and are externally coupled to the system microphone bias line and MIC pin as seen in Figure 8-1. A specially enabled audio interface is able to determine the frequency of the tone, decode the tone into a specific button press, and control system operations accordingly. Most commonly, three button switches are used in the external switch-resistor network tied to the REM pin with the following functions: volume up, volume down, and center button. However, the CD326x supports up to four unique buttons, allowing for more customized functionality. The CD326x also provides authentication, shunt regulation, and power-on-reset (POR) functionality. These are described in Section 7.3.
7.2 Functional Block Diagram
1.56V S Q QRPower-on reset Switch A Switch B Impedence detector Tone generator+ 2.3V Figure 7-1. Functional Block Diagram CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
14 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
7.3 Feature Description
7.3.1 Tone Mode Start-up Timing
2.35V 2.5V 2.5V 2.5V 2.5V 2.5V tOFFB tREG. tM2T. tCAL. tACK. tONA. Figure 7-2. Tone Mode Start-up Timing The tone mode start-up sequence is as follows: 1. After detecting VMIC > 2.35V, the switch connecting the MIC and REM pins together (Switch B) is opened after time tOFFB. 2. After a delay of tONA after VMIC > 2.35V, the VSHUNT and MICPWR pins are shorted (with Switch A). The microphone is enabled by turning on the FET switch that is controlled by the MICPWR pin. 3. After a delay to allow the switches to settle, tM2T after VMIC > 2.35V, the CD326x sends a preset acknowledge (ACK) tone sequence. 4. The specially enabled audio interface detects the ACK sequence and authenticates the presence of the CD326x.
7.3.2 Authentication
To validate connectivity with a specially enabled audio interface, the CD326x provides an authentication sequence upon start-up. After enabling tone mode (applying VMIC > 2.35V typical), the specially enabled audio interface waits to receive an acknowledgment from the CD326x. This acknowledgment is a tone sequence similar to a button press when operating as tone mode. When the CD326x recognizes tone mode upon power- up, the CD326x sends an acknowledgment (ACK) tone sequence to the specially enabled audio interface. The tone frequency is identical to the S1 button press tone for the CD3268 and to the S2 button press tone for the CD3269. However, the ACK tone sequence generates the second tone to be 3.7ms longer compared to the standard tone sequence for button presses. The specially enabled audio interface reads the tone sequence as shown in Figure 7-6. The specially enabled audio interface takes three samples: the first to determine calibration frequency, the second to determine the www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 15 Product Folder Links: CD3268A CD3269A
button/ACK frequency, and the third to differentiate between an authentication sequence and a button press. The third sample is taken 2.89ms after the second sample. If the specially enabled audio interface reads the ACK frequency during the third sample, the interface acknowledges a proper authentication sequence. If the tone frequency is not present during the third sample, the specially enabled audio interface recognizes the tone sequence as a button tone. When a button tone is recognized any time after the timeout period, the specially enabled audio interface records a button press event.
7.3.3 Shunt Regulator
An internal shunt regulator in the CD326x isolates the internal circuitry power supply from the MIC pin. The shunt regulator can provide power to an external microphone module through the MICPWR pin, or the MICPWR output can be used as an enable signal to control power to an external microphone module as shown in Figure 8-1. The CD326x regulates the MICPWR output to approximately 1.56V. The shunt regulator only regulates the VSHUNT and MICPWR pins during tone mode. During button mode operation, the CD326x powers down the regulator. An external resistance between the MIC and VSHUNT pins determines the current into the VSHUNT pin. The shunt regulator requires current of at least 93µA to maintain regulation of the VSHUNT pin. Any excess current becomes available to the load at MICPWR. Any further excess current is internally shunted to ground.
7.3.4 Power-on-reset
The CD326x has an internal power-on-reset (POR) circuit that holds all internal logic in a predetermined reset state until the supply voltage reaches a valid operating level and all internal nodes have stabilized. Figure 7-3 illustrates POR operation. While the MIC pin is below V LVALID (200mV typical), POR is in an indeterminate state. When the supply voltage on the MIC pin is greater than V LVALID, the POR circuit asserts low until the supply rises to V POR-RISE (1.2V typical). When the supply reaches V POR-RISE, the POR function enters a valid operating supply state, and the POR signal remains asserted low for a predetermined delay tDPOR (1ms typical). The POR function remains in the valid operating supply state until the supply voltage on the MIC pin falls below VPOR-FALL (0.8V typical). Upon falling below this threshold, the POR circuit immediately asserts the POR signal and enters the original low-supply state until a valid operating supply voltage is supplied. When the POR circuit recognizes a low-supply voltage during tDPOR, the circuit immediately resets the delay timer, maintains the asserted POR signal, and enters the low-supply state. After a valid operating supply voltage is reached again, the POR circuit repeats the operation. Logic Status RESET RESET ACTIVE ACTIVEX VPOR-RISE VPOR-FALL VLVALID tDPOR 1ms Time Voltage (V) MIC POR tDPOR 1ms 0.8 1.2 0.2 Figure 7-3. Power-on-reset (POR) Logic Signal CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
16 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
7.4 Device Functional Modes
7.4.1 Button Mode
When the CD326x detects a MIC pin voltage below 2.35V (typ) , the CD326x shorts the MIC and REM pins together and disables all other inputs and outputs. When a button press event occurs, the DC voltage on the microphone bias line changes according to the button being pressed. Table 7-1 shows the corresponding DC voltage for a given button press when using the resistor values in Figure 7-4. This DC level can then be detected by a specially enabled audio interface connected to the microphone bias line (MIC pin). Switch S0 is a unique switch (typically controlled by a specially enabled audio interface) that shorts the MIC pin to ground. When Switch S0 shorts the MIC pin to ground, the specially enabled audio interface removes power from the CD326x. When power recovers, the CD326x enters button mode or tone mode depending on the voltage detected at the MIC pin. Table 7-1. Typical Switch Voltage Values (Button mode) Switch Closed MIC Pin Voltage (V) (1) S0 0 S1 1.510 S2 1.603 S3 1.690 S4 1.779 (1) VMICBIAS is the voltage on the MIC pin: 2.0V (typ) REM 6.81k S0 S1 2.61k S2 S3 S4 Phone host audio interface MICBIAS GND 3.57k 6.81k CD326x MIC ≤1% tolerance resistors recommended Figure 7-4. Recommended Button Mode Resistor Values
7.4.2 Tone Mode
When the CD326x detects a value higher than the rising tone mode threshold voltage (2.35V typical) on the MIC pin, the CD326x enters tone mode. When the device transitions to tone mode while supplying voltages below the tone mode threshold voltage, the overshoot voltage from the supply temporarily pushes the MIC pin voltage above the threshold. Decreasing the ramp of the supply or reducing the supply voltage are both options to reduce the inrush current leading to this functionality. Figure 7-5 shows the start-up sequence for when the CD326x enters tone mode. Upon entering tone more, the device opens the switch that connects the MIC and REM pins (Switch B). After a predetermined delay, the device shorts the VSHUNT pin and the MICPWR pin (Switch A). This functionality aids in preventing unwanted noise from the internal circuitry being mixed onto the microphone bias line. Following another predetermined delay, the CD326x sends an acknowledge tone sequence as described in Section 7.3.2. When a microphone is biased and in use, the switch-resistor network used for button mode causes large DC level shifts in the bias voltage. This level shift can result in unwanted, audible clicks, pops, or de-biasing of the microphone. To prevent these results, when the CD326x enters tone mode, the CD326x disconnects the switch- resistor network from the microphone bias line, provides power to an external microphone through a shunt regulator, and engages a tone generation circuit. The TONE pin AC couples the tones onto the microphone bias www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 17 Product Folder Links: CD3268A CD3269A
line for a specially enabled audio interface to interpret. Using the output from the MICPWR pin, the external microphone can be biased directly or through an external circuit as shown in Figure 8-1. During a typical application where IMICPWR falls between 120µA and 150µA, the MICPWR pin provides a voltage from 1.51V to 1.61V (1.56V typical, see VMICPWR). Leaving the MICPWR pin floating or drawing current outside of these limits results in voltage exceeding the MICPWR output voltage specifications. Additionally, increasing the voltage on the MIC pin above 2.5V drives the MICPWR output voltage above 1.61V. Power up Button mode switch A open switch B closed VMIC > 2.3V? N Y Debounce? N Y Press S0? N Y Open switch B Close switch A Send ACK tone Tone mode switch A closed switch B open Button press (S0)? Button press (S1, S2, S3,or S4)? Y N Y Send button tone N Figure 7-5. Tone Mode Power-up Sequence For accuracy, the CD326x transmits two tones for each button press as shown in Figure 7-6. The first tone is enabled for a period of 0.9ms and is a calibration frequency. The second tone is enabled for a period of 1.8ms and is the unique frequency for the selected button. The specially enabled audio interface calculates the ratio of these two frequencies and translates the ratio into button press information. This functionality provides accurate results independent of clock frequency variation. CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
18 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
8 Application and Implementation
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes, as well as validating and testing their design implementation to confirm system functionality.
8.1 Application Information
The CD326x device is a highly efficient, small, and flexible wired headset signaling transmitter compatible with systems including a specially enabled audio interface. The design includes support for systems with and without a microphone while being compatible with up to four unique buttons.
8.2 Typical Application
6.81k RTONE 20k CTONE 200pF RVSHUNT 1.0k CVSHUNT 0.1µF 2.61k S2 S3 S4 Microphone module VMIC Phone host audio interface INT MICBIAS GND 3.57k 6.81k Figure 8-1. Typical Application
8.2.1 Design Requirements
Table 8-1. Typical Component Values PARAMETER VALUE UNIT CMIC MIC capacitor 10 µF CVSHUNT VSHUNT capacitor 0.1 CTONE TONE capacitor 200 pF RMIC MIC resistor 1.0 kΩ RVSHUNT VSHUNT resistor 1.0 RTONE TONE resistor 20.0 R1 S1 switch resistor 6.81 R2 S2 switch resistor 2.61 R3 S3 switch resistor 3.57 R4 S4 switch resistor 6.81 CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
20 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
8.2.2 Application Curves
Figure 8-2 shows the tone generated from applying different resistance values on the REM pin. Applying and removing a resistance to the REM pin simulates a button press event which is detected by the CD326x. Recommended button resistor values can be found in Figure 7-4 and Section 5.5 (specifically button boundaries). Additionally, there are three sets of resistances between each band where either the generated tone is unstable, or where the device does not generate a tone (see Table 8-2). R E M P i n R e s i s t a n c e ( k ) Tone Rario 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 0 . 4 5 0 . 5 0 . 5 5 0 . 6 0 . 6 5 0 . 7 0 . 7 5 0 . 8 0 . 8 5 0 . 9 Figure 8-2. Generated Tone from REM Resistance Value Table 8-2. Deadband Ranges Button Transition Deadband Range From To Low (kΩ) High (kΩ) Button 1 Button 2 7.85 7.95 Button 2 Button 3 10.60 11.00 Button 3 Button 4 15.50 15.90 For Figure 8-3 and Figure 8-4, active currents refer to the currents drawn by the VMIC and VSHUNT pins when a tone is being generated as part of tone mode operation. A m b i e n t T e m p e r a t u r e ( C ) MIC Pin Current (mA) - 5 0 - 2 5 0 2 5 5 0 7 5 1 0 0 2 0 2 2 2 4 2 6 2 8 3 0 3 2 Figure 8-3. Active Current into MIC Pin vs Temperature A m b i e n t T e m p e r a t u r e ( C ) VSHUNT Pin Current (mA) - 5 0 - 2 5 0 2 5 5 0 7 5 1 0 0 9 4 9 5 9 6 9 7 9 8 9 9 1 0 0 Figure 8-4. Active Current into VSHUNT Pin vs Temperature www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 21 Product Folder Links: CD3268A CD3269A
8.3 Power Supply Recommendations
The power supply to the CD326x must have a current rating according to the supply voltage, output voltage, supply current, and output current of the CD326x.
8.4 Layout
8.4.1 Layout Guidelines
The system level performance metrics, including thermal performance, electromagnetic compliance (EMC), device reliability, and audio performance are all affected by the device and supporting component layout. The guidance provided in the applications section with regard to device and component selection can be followed by precise adherence to the layout guidance shown in the Section 8.4.2. This example represents an exemplary baseline balance of the engineering trade-offs involved with lying out the device. This design can be modified slightly as needed to meet the needs of a given application. In some applications, for instance, footprint size can be compromised to improve thermal performance through the use of additional contiguous copper neat the device. Conversely, EMI performance can be prioritized over thermal performance by routing on internal traces and incorporating a via picket-fence and additional filtering components. The recommended process is to start with the guidance shown in the Section 8.4.2 and work with TI field application engineers or through the E2E community to modify the layout based upon the application specific goals.
- See Figure 8-5 for the recommended layout of the CD326x, which is designed for common external GND connections. TI recommends placing all components as close as possible to the package pins. The recommended layout is implemented on the EVM and shown in the EVM user's guide.
- Provide low capacitive paths (with respect to all other nodes) for traces with high dv/dt. Therefore, the input and output capacitance must be placed as close as possible to the IC pins and parallel wiring over long distances as well as narrow traces must be avoided. Loops which conduct an alternating current must outline an area as small as possible, as this area is proportional to the energy radiated
- Use a ground plane with multiple vias for each terminal to create a low-impedance connection to GND for minimum ground noise.
- A single common GND plane is recommended to avoid a potential voltage difference between signals.
- When placing decoupling capacitors, especially for the VSHUNT pin, place the capacitors as close to the device as possible. Typically recommended capacitor is 0.1µF. CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
22 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
8.4.2 Layout Example
(optional) VMIC supply REM Normal routing Microphone routing (optional) Ground Figure 8-5. Layout Example www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 23 Product Folder Links: CD3268A CD3269A
9 Device and Documentation Support
TI offers an extensive line of development tools. Tools and software to evaluate the performance of the device, generate code, and develop solutions are listed below.
9.1 Device Support
9.1.1 Third-Party Products Disclaimer
TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE.
9.1.2 Development Support
For development support on this product, see the following:
- Chapter 54: Headset Remote and Microphone Transmitter in Accessory Design Guidelines for Apple Devices from the Apple Development Page
9.2 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on Notifications to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document.
9.3 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight from the experts. Search existing answers or ask your own question to get the quick design help you need. Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use.
9.4 Trademarks
TI E2E™ is a trademark of Texas Instruments. iPhone® and iPad® are registered trademarks of Apple, Inc.. All trademarks are the property of their respective owners.
9.5 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
9.6 Glossary
TI Glossary This glossary lists and explains terms, acronyms, and definitions. NOTE: Page numbers for previous revisions may differ from page numbers in the current version. DATE REVISION NOTES May 2025 * Initial Release CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
24 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
11 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 25 Product Folder Links: CD3268A CD3269A
C0.5 MAX 0.19 0.15 TYP
0.5 TYP
6X 0.25 0.21 0.5 TYP B E A D 4219524/A 06/2014 NanoFree Is a trademark of Texas Instruments. DSBGA - 0.5 mm max heightYZP0006 DIE SIZE BALL GRID ARRAY NOTES: BALL A1 CORNER SEATING PLANE BALL TYP 1.All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2.This drawing is subject to change without notice. 3.NanoFree package configuration. TM 0.05 C B A 1 2
0.015 C A B
C SCALE 9.000 CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
26 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
6X ( 0.225) (0.5) TYP (0.5) TYP ( ) METAL 0.225 0.05 MAX SOLDER MASK OPENING METAL UNDER MASK ( ) SOLDER MASK OPENING 0.225
0.05 MIN
DSBGA - 0.5 mm max heightYZP0006 DIE SIZE BALL GRID ARRAY NOTES: (continued) For more information, see Texas Instruments literature number SBVA017 (www.ti.com/lit/sbva017). 4.Final dimensions may vary due to manufacturing tolerance considerations and also routing constraints. SYMM SYMM LAND PATTERN EXAMPLE SCALE:40X 1 2 A B C SOLDER MASK NON-SOLDER MASK DEFINED (PREFERRED) NOT TO SCALE SOLDER MASK DETAILS DEFINED www.ti.com CD3268A, CD3269A SCHS463 – MAY 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 27 Product Folder Links: CD3268A CD3269A
(0.5) TYP (0.5) TYP 6X ( 0.25) METAL (R0.05) TYP TYP 4219524/A 06/2014 DSBGA - 0.5 mm max heightYZP0006 DIE SIZE BALL GRID ARRAY NOTES: (continued) 5. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. SYMM 1 2 A SYMM BASED ON 0.1 mm THICK STENCIL SCALE:40X SOLDER PASTE EXAMPLE B C CD3268A, CD3269A SCHS463 – MAY 2025 www.ti.com
28 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: CD3268A CD3269A
www.ti.com 14-Oct-2025 PACKAGING INFORMATION Orderable part number Status (1) Material type (2) Package | Pins Package qty | Carrier RoHS (3) Lead finish/ Ball material (4) MSL rating/ Peak reflow (5) Op temp (°C) Part marking (6) CD3268A0YZPR Active Production DSBGA (YZP) | 6 3000 | LARGE T&R Yes SNAGCU Level-1-260C-UNLIM -40 to 85 (4H3, 4H5) CD3269A0YZPR Active Production DSBGA (YZP) | 6 3000 | LARGE T&R Yes SNAGCU Level-1-260C-UNLIM -40 to 85 (4J3, 4J5) (1) Status: For more details on status, see our product life cycle. (2) Material type: When designated, preproduction parts are prototypes/experimental devices, and are not yet approved or released for full production. Testing and final process, including without limitation quality assurance, reliability performance testing, and/or process qualification, may not yet be complete, and this item is subject to further changes or possible discontinuation. If available for ordering, purchases will be subject to an additional waiver at checkout, and are intended for early internal evaluation purposes only. These items are sold without warranties of any kind. (3) RoHS values: Yes, No, RoHS Exempt. See the TI RoHS Statement for additional information and value definition. (4) Lead finish/Ball material: Parts may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two lines if the finish value exceeds the maximum column width. (5) MSL rating/Peak reflow: The moisture sensitivity level ratings and peak solder (reflow) temperatures. In the event that a part has multiple moisture sensitivity ratings, only the lowest level per JEDEC standards is shown. Refer to the shipping label for the actual reflow temperature that will be used to mount the part to the printed circuit board. (6) Part marking: There may be an additional marking, which relates to the logo, the lot trace code information, or the environmental category of the part. Multiple part markings will be inside parentheses. Only one part marking contained in parentheses and separated by a "~" will appear on a part. If a line is indented then it is a continuation of the previous line and the two combined represent the entire part marking for that device. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1
PACKAGE MATERIALS INFORMATION www.ti.com 11-Oct-2025 TAPE AND REEL INFORMATION Reel Width (W1) REEL DIMENSIONS A0B0K0WDimension designed to accommodate the component lengthDimension designed to accommodate the component thicknessOverall width of the carrier tapePitch between successive cavity centersDimension designed to accommodate the component width TAPE DIMENSIONSK0 P1B0WA0Cavity QUADRANT ASSIGNMENTS FOR PIN 1 ORIENTATION IN TAPE Pocket QuadrantsSprocket HolesQ1Q1Q2Q2Q3Q3Q4Q4User Direction of Feed P1ReelDiameter *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Reel Diameter (mm) Reel Width W1 (mm) (mm) (mm) (mm) (mm) W (mm) Pin1 Quadrant Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION www.ti.com 11-Oct-2025 TAPE AND REEL BOX DIMENSIONS Width (mm) W LH *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) CD3268A0YZPR DSBGA YZP 6 3000 220.0 220.0 35.0 CD3269A0YZPR DSBGA YZP 6 3000 220.0 220.0 35.0 Pack Materials-Page 2
www.ti.com PACKAGE OUTLINE C0.5 MAX 0.19 0.15 TYP 6X 0.25 0.21 0.5 TYP B E A D 4219524/A 06/2014 DSBGA - 0.5 mm max heightYZP0006 DIE SIZE BALL GRID ARRAY NOTES: 1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. NanoFree TM package configuration. NanoFree Is a trademark of Texas Instruments. BALL A1 CORNER SEATING PLANE BALL TYP 0.05 C B A 1 2 C SCALE 9.000 D: Max = E: Max = 1.418 mm, Min = 0.918 mm, Min = 1.358 mm 0.858 mm
www.ti.com EXAMPLE BOARD LAYOUT 6X ( ) 0.225 (0.5) TYP (0.5) TYP ( ) METAL 0.225 0.05 MAX SOLDER MASK OPENING METAL UNDER MASK SOLDER MASK OPENING 0.225 DSBGA - 0.5 mm max heightYZP0006 DIE SIZE BALL GRID ARRAY NOTES: (continued) 4. Final dimensions may vary due to manufacturing tolerance considerations and also routing constraints. For more information, see Texas Instruments literature number SBVA017 (www.ti.com/lit/sbva017). SYMM SYMM LAND PATTERN EXAMPLE SCALE:40X 1 2 A B C NON-SOLDER MASK DEFINED (PREFERRED) SOLDER MASK DETAILS NOT TO SCALE SOLDER MASK DEFINED
www.ti.com EXAMPLE STENCIL DESIGN (0.5) TYP (0.5) TYP 6X ( 0.25) (R ) TYP 0.05 METAL TYP 4219524/A 06/2014 DSBGA - 0.5 mm max heightYZP0006 DIE SIZE BALL GRID ARRAY NOTES: (continued) 5. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. SYMM SYMM SOLDER PASTE EXAMPLE BASED ON 0.1 mm THICK STENCIL SCALE:40X 1 2 A B C
IMPORTANT NOTICE AND DISCLAIMER TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATA SHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, regulatory or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources. TI’s products are provided subject to TI’s Terms of Sale or other applicable terms available either on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable warranties or warranty disclaimers for TI products. TI objects to and rejects any additional or different terms you may have proposed. IMPORTANT NOTICE Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2025, Texas Instruments Incorporated