DS4412

DS4412 MAXIM | Alldatasheet

Document overview

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Technical content

Features

♦ Two Current DACs ♦ Full-Scale Current 500µA to 2mA ♦ Full-Scale Range for Each DAC Determined by External Resistors ♦ 15 Settings Each for Sink and Source Modes ♦ I2C-Compatible Serial Interface ♦ Low Cost ♦ Small Package (8-Pin µSOP) ♦ -40°C to +85°C Temperature Range ♦ 2.7V to 5.5V Operation DS4412 Dual-Channel, I2C Adjustable Sink/Source Current DAC DC-DC CONVERTER FB OUT SDA SCL OUT0 OUT1 GND RFS0 RFS1 4.7kΩ4.7kΩ VCC VCC VOUT0 FS0 FS1 R0B R0A DC-DC CONVERTER FB OUT VOUT1 R1B R1A DS4412 Typical Operating Circuit

Ordering Information

Rev 0; 9/07 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. +Denotes a lead-free package. T&R = Tape and reel. PART TEMP RANGE PIN-PACKAGE DS4412U+ -40°C to +85°C 8 μSOP DS4412U+T&R -40°C to +85°C 8 μSOP VCC OUT1 OUT0 FS0GND FS1 SCL SDA μSOP TOP VIEW DS4412 Pin Configuration

Dual-Channel, I2C Adjustable Sink/Source Current DAC ABSOLUTE MAXIMUM RATINGS RECOMMENDED OPERATING CONDITIONS (TA = -40°C to +85°C) 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 in the operational sections of the specificatio ns is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Voltage Range on VCC, SDA, and SCL Voltage Range on OUT0, OUT1 Relative to J-STD-020 Specification PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V CC (Note 1) 2.7 5.5 V Input Logic 1 (SDA, SCL) V IH 0.7 x VCC VCC + 0.3 V Input Logic 0 (SDA, SCL) V IL -0.3 0.3 x VCC V DC ELECTRICAL CHARACTERISTICS (VCC = +2.7V to +5.5V, TA = -40°C to +85°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Current I CC V CC = 5.5V (Note 2) 500 μA Input Leakage (SDA, SCL) I IL V CC = 5.5V 1 μA Output Leakage (SDA) I L 1 μA VOL = 0.4V 3 Output Current Low (SDA) I OL VOL = 0.6V 6 mA RFS Voltage V RFS 0.607 V OUTPUT CURRENT CHARACTERISTICS (VCC = +2.7V to +5.5V, TA = -40°C to +85°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Output Voltage for Sinking VOUT:SINK V CC > VOUT:SINK (Note 3) 0.5 3.5 V Output Voltage for Sourcing Current VOUT:SOURCE (Note 3) 0 VCC - 0.75 V Full-Scale Sink Output Current I OUT:SINK (Note 3) 0.5 2.0 mA Full-Scale Source Output Current I OUT:SOURCE (Note 3) -2.0 -0.5 mA Output-Current Full-Scale Accuracy IOUT:FS +25°C, VCC = 4.0V; using 0.1% R FS resistor (Note 4) VOUT0 = VOUT1 = 1.2V ±6 % Output-Current Temperature Coefficient IOUT:TC (Note 5) ±75 ppm/°C DC source +0.36Output-Current Variation due to Power-Supply Change DC sink +0.12 %/V

Dual-Channel, I2C Adjustable Sink/Source Current DAC Note 1: All voltages with respect to ground, currents entering the IC are specified positive and currents exiting the IC are negative. Note 2: Supply current specified with all outputs set to zero current setting with all inputs driven to well-defined logic levels. SDA and SCL are connected to VCC. Excludes current through RFS resistors (IRFS). Total current includes ICC + 2.5 x (IRFS0 + IRFS0). Note 3: The output voltage range must be satisfied to ensure the device meets its accuracy and linearity specifications. Note 4: Input resistors RFS must be between 2.25kΩ and 9.0kΩ to ensure the device meets its accuracy and linearity specifications. Note 5: Temperature drift excludes drift caused by external resistor. Note 6: Differential linearity is defined as the difference between the expected incremental current increase with respect to position and the actual increase. The expected incremental increase is the full-scale range divided by 15. Note 7: Integral linearity is defined as the difference between the expected value as a function of the setting and the actual value. The expected value is a straight line between the zero and the full-scale values proportional to the setting. Note 8: Timing shown is for fast-mode (400kHz) operation. This device is also backward compatible with I2C standard-mode timing. Note 9: CB—total capacitance of one bus line in pF. OUTPUT CURRENT CHARACTERISTICS (continued) (VCC = +2.7V to +5.5V, TA = -40°C to +85°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC source, VOUT measured at 1.2V -0.02 Output-Current Variation due to Output Voltage Change DC sink, V OUT measured at 1.2V +0.12 %/V Output Leakage Current at Zero Current Setting IZERO -1 +1 μA Output-Current Differential Linearity DNL (Note 6) 0.5 LSB Output-Current Integral Linearity INL (Note 7) 1 LSB I2C AC ELECTRICAL CHARACTERISTICS (VCC = +2.7V to +5.5V, TA = -40°C to +85°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SCL Clock Frequency f SCL (Note 8) 0 400 kHz Bus Free Time Between STOP and START Conditions tBUF 1.3 µs Hold Time (Repeated) START Condition tHD:STA 0.6 µs Low Period of SCL t LOW 1.3 µs High Period of SCL t HIGH 0.6 µs Data Hold Time t DH:DAT 0 0.9 µs Data Setup Time t SU:DAT 100 ns START Setup Time t SU:STA 0.6 µs SDA and SCL Rise Time t R (Note 9) 20 + 0.1CB 300 ns SDA and SCL Fall Time t F (Note 9) 20 + 0.1CB 300 ns STOP Setup Time t SU:STO 0.6 µs SDA and SCL Capacitive Loading C B (Note 9) 400 pF

SDA 1 I 2C Serial Data. Input/output for I 2C data. SCL 2 I 2C Serial Clock. Input for I 2C clock. FS1 3 FS0 5 Full-Scale Calibration Inputs. A resistor to ground on these pins determines the full-scale current for each output. FS0 controls OUT0, FS1 controls OUT1. GND 4 Ground OUT0 6 OUT1 7 Current Outputs. Sinks or sources the current determined by the register settings and the resistance connected to FS0 and FS1. VCC 8 Power Supply DS4412 Dual-Channel, I2C Adjustable Sink/Source Current DAC Typical Operating Characteristics (Applies to OUT0 and OUT1. VCC = 2.7V to 5.0V, SDA = SCL = VCC, TA = +25°C, and no loads on OUT0, OUT1, FS0, or FS1, unless otherwise noted.) SUPPLY CURRENT vs. TEMPERATURE DS4412 toc02 TEMPERATURE (°C) SUPPLY CURRENT (mA) 806040200-20 0.05 0.10 0.15 0.20 0.25 0.30 0.35 -40 VCC = 5.0V VCC = 3.3V VCC = 2.7V DOES NOT INCLUDE CURRENT DRAWN BY RESISTORS CONNECTED TO FS0 AND FS1. VOLTCO (SOURCE) DS4412 toc03 VOUT (V) IOUT (mA) 4321 2.1 2.2 2.3 2.4 2.5 2.0 2.2kΩ LOAD ON FS0 AND FS1 SUPPLY CURRENT vs. SUPPLY VOLTAGE DS4412 toc01 SUPPLY VOLTAGE (V) SUPPLY CURRENT (mA) 0.1 0.2 0.3 0.4 0.5 2.7 DOES NOT INCLUDE CURRENT DRAWN BY RESISTORS CONNECTED TO FS0 AND FS1. VOLTCO (SINK) DS4412 toc04 VOUT (V) IOUT (mA) 321 -2.4 -2.3 -2.2 -2.1 -2.0 -2.5 2.2kΩ LOAD ON FS0 AND FS1 TEMPERATURE COEFFICIENT vs. SETTING (SOURCE) DS4412 toc05 SETTING (DEC) TEMPERATURE COEFFICIENT (°C/ppm) 105 01 5 +25°C TO -40°C +25°C TO +85°C RANGE FOR THE 0.5mA TO 2.0mA CURRENT-SOURCE RANGE. TEMPERATURE COEFFICIENT vs. SETTING (SINK) DS4412 toc06 SETTING (DEC) TEMPERATURE COEFFICIENT (°C/ppm) 105 01 5 +25°C TO -40°C +25°C TO +85°C RANGE FOR THE 0.5mA TO 2.0mA CURRENT-SOURCE RANGE.

Dual-Channel, I2C Adjustable Sink/Source Current DAC Typical Operating Characteristics (continued) (Applies to OUT0 and OUT1. VCC = 2.7V to 5.0V, SDA = SCL = VCC, TA = +25°C, and no loads on OUT0, OUT1, FS0, or FS1, unless otherwise noted.) DIFFERENTIAL LINEARITY DS4412 toc08 SETTING (DEC) DNL (LSB) 105 -0.8 -0.6 -0.4 -0.2 0.2 0.4 0.6 0.8 1.0 -1.0 01 5 RANGE FOR THE 0.5mA TO 2.0mA CURRENT SOURCE AND SINK RANGE INTEGRAL LINEARITY DS4412 toc07 SETTING (DEC) INL (LSB) 105 -0.7500 -0.5000 -0.2500 0.0000 0.2500 0.5000 0.7500 1.0000 -1.0000 01 5 RANGE FOR THE 0.5mA TO 2.0mA CURRENT SOURCE AND SINK RANGE

Characteristics), and RFS is the external resistor value. chance to modify the device’s setting. the most out of its 4-bit sink or source resolution. defaults to providing zero output current on power-up. to the memory addresses in Table 1. a value of 0x8Ah. Calculate the output current. Table 1. Memory Addresses

DS4412’s slave address is 90h. Figure 2. I2C Communication Examples

Dual-Channel, I2C Adjustable Sink/Source Current DAC Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circu it patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 9 © 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

Application Information

for an Adjustable Power Supply In this example, the Typical Operating Circuit is used as a base to create Figure 3, a 2.0V voltage supply with ±20% margin. The adjustable power supply has a DC-DC converter output voltage, V OUT, of 2.0V and a DC-DC converter feedback voltage, V FB, of 0.8V. To determine the relationship of R0A and R0B, we start with the equation: Substituting VFB = 0.8V and V OUT = 2.0V, the relation- ship between R0A and R0B is determined to be: R0A = 1.5 x R0B IOUT0 is chosen to be 1mA (midrange source/sink cur- rent for the DS4412). Summing the currents into the feedback node, we have the following Where: And To create a 20% margin in the supply voltage, the value of V OUT is set to 2.4V. With these values in place, R0B is calculated to be 267Ω, and R0A is calculated to be 400Ω. The current DAC in this configuration allows the output voltage to be moved linearly from 1.6V to 2.4V using 15 settings. This corresponds to a resolution of 25.8mV/step. VCC Decoupling To achieve the best results when using the DS4412, decouple the power supply with a 0.01µF or 0.1µF capacitor. Use a high-quality ceramic surface-mount capacitor if possible. Surface-mount components mini- mize lead inductance, which improves performance, and ceramic capacitors tend to have adequate high- frequency response for decoupling applications. I VV RRA OUT FB A I V RRB FB B II IOUT R B R A00 0= − V R RR VFB B AB OUT= + ×0 DC-DC CONVERTER FB OUT SDA SCL OUT0 GND RFS0 = 4.612kΩ 4.7kΩ4.7kΩ VCC VCC VOUT = 2.0V FS0 R0B = 267Ω R0A = 400Ω VFB = 0.8V IR0A IR0B IOUT0 DS4412 Figure 3. Example Application Circuit

Package Information

For the latest package outline information, go to www.maxim-ic.com/DallasPackInfo.