TMPA2155DS

TMPA2155DS ETC1 | Alldatasheet

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Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 1 2.7W/CH STEREO CLASS-D AUDIO POWER AMPLIFIER GENERAL DESCRIPTION The TMPA2155DS is a stereo class-D audio power amplifier IC. With BTL(Bridge-Tied-Load) configuration, it delivers up to 2.7W/ch(5.4W in all) into a 3 ohm load or 2.3W/ch(4.6W in all) into a 4 ohm load or 1.5W/ch(3W in all) into an 8 ohm load. No external heat-sink is required. For multiple-input applications, independent gain control and corner frequency can be implemented by summing the input sources through resistor ratio and input capacitor values. Automatic voltage gain control makes the best use of battery. Analog input signal is converted into digital output which drives directly to the speaker. High power efficiency is achieved due to digital output at the load. The audio information is embedded in PWM（Pulse Width Modulation）.

APPLICATIONS

Multimedia application includes Cellular Phones, PDAs, DVD/CD players, TFT LCD TVs/Monitors, 2.1 channel/5.1 channel audio systems, USB audio. It is also ideal for other portable devices like Wireless Radios.

FEATURES

♦ 2.5V to 6V Single Supply ♦ Up to 2.7W / Ch at 5V, 3 ohms ♦ Up to 85% Power Efficiency ♦ Automatic output power control (APC) ♦ 2.2mA / Ch Quiescent Current at 5V ♦ Less Than 0.2uA / Ch Shutdown Current ♦ Pop-less Power-Up, Shutdown and Recovery ♦ Differential 250 KHz PWM Allows Bridge-Tied Load to Doubles Output Power and Eliminates LC Output Filter ♦ Thermal Shutoff and Automatic Recovery ♦ Compatible with earphone application ♦ Output Pin Short-Circuit Protection (Short to Other Outputs, Short to VCC, Short to Ground) ♦ Differential Signal Processing Improves CMRR Package TSSOP20, QFN24 Available For best performance, please refer to http://www.taimec.com.tw/English/EVM.htm http://www.class-d.com.tw/English/EVM.htm for PCB layout. REFERENCE CIRCUIT（Please refer to TMPA002.APP for application） PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 2 （Please email david@taimec.com.tw for complete datasheet.） Tai-1 Microelectronics reserves the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers are responsible for their products and applications using Tai-1 Microelectronics components. Note that the external components or PCB layout should be designed not to generate abnormal voltages to the chip to prevent from latch up which may cause damage to the device. Typical Application S1switch C13 470uF(6.3V) 1uF(6.3V) 1uF(6.3V) 1uF(6.3V)(optional) 33uH 1uF(6.3V)(optional) 1 20 2 19 3 18 4 17 5 16 6 15 LOUTP VDD RINN LINP LINN NC RINP NC GND LOUTN VDD SDNB AVDD AGND ROUTP VDD9 CAP VDD ROUTN GND11 JP1 2155DS(FD) C10 1uF(6.3V) 33uH 1uF(6.3V) 33uH C12 1uF(6.3V) 33uH SDN VO1+ VO1- VO2- VO2+ R5 100 R10 10K 1uF(6.3V) 1uF(6.3V) 1uF(6.3V) 1uF(6.3V) C11 1uF(6.3V) C14 470p(6.3V) C15 470p(6.3V) C16 1uF(6.3V) C17 1uF(6.3V) LS1 LS2 PHONEJACK STEREO VR VDD 22k 22k 22k 22k 330 330 R12 ABSOLUTE MAXIMUM RATINGS Over operating free-air temperature range unless otherwise noted(1) In normal mode -0.3V to 6V V Supply voltage, VDD, AVDD In shutdown mode -0.3V to 7V V Input voltage, VI -0.3V to VDD+0.3V V Continuous total power dissipation See package dissipation ratings Operating free-air temperature, TA -20 to 85 。C Operating junction temperature, TJ -20 to 150 。C Storage temperature, Tstg -40 to 150 。C (1) Stresses beyond those listed under”absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions “is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 3 kohms15Ri kohms320Gain += RECOMMENDED OPERATING CONDITONS MIN NOM MAX UNIT Supply voltage, VDD, AVDD 2.5 6 V High-level input voltage, VIH SDNB 2 VDD V Low-level input voltage, VIL SDNB 0 0.8 V Operating free-air temperature, TA -20 85 。C PACKAGE DISSIPATION RATINGS PACKAGE DERATING FACTOR TA ≤ 25。C POWER RATING TA = 70。C POWER RATING TA = 85。C POWER RATING TSSOP20 8.73 mW/。C 1.09W 698mW 567mW

ELECTRICAL CHARACTERISTICS

TA=25。C (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT │VOS│ Output offset voltage (measured differentially) VI=0V,AV=2, VDD=AVDD=2.5V to 5.5V 25 mV PSRR Power supply rejection ratio VDD=AVDD=2.5V to 5.5V -75 -55 dB CMRR Common mode rejection ratio VDD=AVDD=2.5V to 5.5V, VIC=1Vpp, RL=8Ω -55 -50 dB │IIH│ High-level input current VDD=AVDD=5.5V, VI=5.8V (SDNB) 30 μA │IIL│ Low-level input current VDD=AVDD=5.5V, VI=-0.3V (SDNB) 1 μA IQ Quiescent current / Ch VDD=AVDD=5V, no load 2.2 3 mA rDS(on) Static output resistance VDD=AVDD=5.5V 790 mΩ f(sw) Switching frequency VDD=AVDD=2.5V to 5.5V 230 280 330 kHz *Av BTL Gain VDD=AVDD=2.5V to 5.5V, RL=8Ω 12 16 20 V V RSDN Resistance from shutdown to GND V(SDNB)=5V 200 kΩ ZI Input impedance RINN,RINP,LINN,LINP 15 kΩ *The gain of the amplifier is determined by, for VDD=VDDA =2.5V to 5.5V where Ri is the external serial resistance at the input pin. PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 4 OPERATING CHARACTERISTICS TA=25。C, RL=8Ω speaker (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT RL=8Ω 1.5 W RL=4Ω 2.3 W PO Output power / Ch (Limited by thermal condition) RL=3Ω VDD=AVDD=5V. THD+N=10%,f=1kHz. 2.7 W VDD=AVDD=5V, PO=0.85W, RL=8Ω, f=1kHz 0.55 VDD=AVDD=5V, PO=1.3W, RL=4Ω, f=1kHz 0.55 THD+N Total harmonic distortion plus noise VDD=AVDD=5V, PO=1.5W, RL=3Ω, f=1kHz 0.64 SNR Signal-to-noise ratio VDD=AVDD=5V, PO=1W, RL=8Ω 95 dB Crosstalk Crosstalk between outputs VDD=AVDD=5V, PO=1W RL=8Ω -68 dB TERMINAL FUNCTIONS TERMINAL NAME PIN NO I/O DESCRIPTION AGND 15 - Analog ground AVDD 16 - Analog Power supply CAP 14 I Capacitance for power up delay GND 11,20 - Digital ground LINN 5 I Negative input of left channel LINP 4 I Positive input of left channel LOUTN 19 O Negative output of left channel LOUTP 1 O Positive output of left channel NC 3,8 - No Connection RINN 6 I Negative input of right channel RINP 7 I Positive input of right channel ROUTN 12 O Negative output of right channel ROUTP 10 O Positive output of right channel SDNB 17 I Shutdown terminal (active low logic) VDD 2,9,13,18 - Digital Power supply TYPICAL CHARACTERISTICS Note 1. Input coupling 1µF capacitors are used for all measurements. 2. Differential inputs are applied and BTL outputs are measured. 3. Balanced LC filter is used for THD+N measurement and power efficiency measurement. 4. Characteristic frequency of the LC filter is set 41KHz unless otherwise specified. PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 5

APPLICATION INFORMATION

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Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 6 PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 7 kohms15Ri kohms320Gain += l Input Resistors and Gain The gain of the amplifier is determined by, for VDD=VDDA =2.5V to 5.5V where Ri is the external serial resistance at the input pin. Note：Please refer to document 010 APP for more application examples. PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 8 DETAILED DESCRIPTION Efficiency The output transistors of a class D amplifier act as switches. The power loss is mainly due to the turn on resistance of the output transistors when driving current to the load. As the turn on resistance is so small that the power loss is small and the power efficiency is high. With 8 ohm load the power efficiency can be better than 85%. Shutdown The shutdown mode reduces power consumption. A LOW at shutdown pin forces the device in shutdown mode and a HIGH forces the device in normal operating mode. Shutdown mode is useful for power saving when not in use. This function is useful when other devices like earphone amplifier on the same PCB are used but class D amplifier is not necessary. Internal circuit for shutdown is shown below. Pop-less A soft start capacitor can be added to the CAP pin. This capacitor introduces delay for the internal circuit to be stable before driving the load. The pop or click noise when power up/down or switching in between shutdown mode can be thus eliminated. The delay time is proportional to the value of the capacitance. It is about 500ms for a capacitor of 1uF at 5v. CAP Cap provides a way of soft startup delay. A 5uA current source and a half_Vcc detector are integrated in the chip. The charged capacitor is externally hooked up. For C=1uF the half_Vcc delay is T = CV / I = （1uF × 2.5V ）/ 5uA = 0.5 seconds PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 9 Voltage gain The voltage gain is defined in the table on page 3. For lower voltage gain one can add external input resistors to input pins. If external resistors are used they should be well matched. Well matched input resistors are also required even for single ended input configuration for low noise. Automatic output Power Control (APC) The voltage gain is self adjusted in the chip over voltage range. This means that, regardless supply voltage change, the output power keeps about the same for a given input level from VDD=5.5v to 2.5v. It allows the best use of the battery. Differential input VS single ended input Differential input offers better noise immunity over single ended input. A differential input amplifier suppresses common noise and amplifies the difference voltage at the inputs. For single ended applications just tie the negative input end of the balanced input structure to ground. If external input resistors are used, the negative input has to be grounded with a series resistor of the same value as the positive input to reduce common noise. Output filter Ferrite bead filter can be used for EMI purpose. The ferrite filter reduces EMI around 1 MHz and higher（FCC and CE only test radiated emissions greater than 30 MHz ）. When selecting a ferrite bead, choose one with high impedance at high frequencies, but low impedance at low frequencies. Use an LC output filter if there are low frequency（＜1 MHz）EMI sensitive circuits and/or there are long wires from the amplifier to the speaker. EMI is also affected by PCB layout and the placement of the surrounding components. PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 10 The suggested LC values for different speaker impendence are showed in following figures for reference. Typical LC Output Filter (1) 0.1μ F 0.1μ F Vo+ Vo- 33μH 33μH 0.47μ F Typical LC Output Filter (2) Over temperature protection A temperature sensor is built in the device to detect the temperature inside the device. When a high temperature around 145 oC and above is detected the switching output signals are disabled to protect the device from over temperature. Automatic recovery circuit enables the device to come back to normal operation when the internal temperature of the device is below around 120oC. PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 11 Over current protection A current detection circuit is built in the device to detect the switching current of the output stages of the device. It disables the device when the current is beyond about 3.5amps. It protects the device when there is an accident short between outputs or between output and power/gnd pins. It also protects the device when an abnormal low impedance is tied to the output. High current beyond the specification may potentially causes electron migration and permanently damage the device. Shutdown or power down is necessary to resolve the protection situation. There is no automatic recovery from over current protection. PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 12 Physical Dimensions (IN MILLIMETERS)

4.16 TYP

7.72 TYP

0.42 TYP

0.65 TYP

(1.78 TYP) LAND PATTERN TSSOP20 PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 13 QFN24 PDF created with pdfFactory trial version www.pdffactory.com

Tai-1 Microelectronics Preliminary TMPA2155DS Copyright©2005, Tai-1 Microelectronics Corp. 14 IMPORTANT NOTICE Tai-1 Microelectronics Corp. reserves the right to make changes to its products and services and to discontinue any product or service without notice. Customers should obtain the latest relevant information for reference. Testing and quality control techniques are used to screen the parameters. Testing of all parameters of each product is not necessarily performed. Tai-1 Microelectronics Corp. assumes no liability for applications assistance or customer product design. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. Reproduction of information in data sheets or related documentation is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Tai-1 Microelectronics Corp. is not responsible or liable for such altered documentation. Resale of Tai-1 Microelectronics Corp. products or services with statements different from the parameters stated by Tai-1 Microelectronics Corp. for that product or service voids all express and any implied warranties. Tai-1 Microelectronics Corp. is not responsible or liable for any such statements. Copyright ©2005,Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com