A3973SB Allegro Microsystems Inc, A3973SB Datasheet
A3973SB
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A3973SB Summary of contents
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Dual DMOS Full-Bridge Microstepping PWM Motor Driver Discontinued Product This device is no longer in production. The device should not be purchased for new design applications. Samples are no longer available. Date of status change: November 1, 2010 Recommended Substitutions: ...
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Dual DMOS Full-Bridge Microstepping PWM Motor Driver Features and Benefits ▪ ± Continuous Output Rating ▪ Low R DMOS Output Drivers DS(on) ▪ Optimized Microstepping via 6-Bit Linear DACs ▪ Programmable Mixed, Fast, and Slow Current Decay Modes ▪ 4 MHz Internal Oscillator for Digital Timing ▪ Serial-Interface Controls Chip Functions ▪ Synchronous Rectification for Low Power Dissipation ▪ Internal UVLO and Thermal Shutdown Circuitry ▪ Crossover-Current Protection ▪ Precision 2 V Reference ▪ Inputs Compatible with 3 Control Signals ▪ Sleep and Idle Modes Packages: Package B, 24-pin DIP with two batwing power tabs Package LB, 24 pin ...
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... A3973 Selection Guide Part Number A3973SB-T* 24 pin DIP with two power tabs A3973SLBTR-T 24 pin SOICW with four internally fused pins *Variant is in production but has been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of the variant is currently restricted to existing customer applications. The variant should not be purchased for new design applica- tions because obsolescence in the near future is probable ...
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A3973 LOGIC SUPPLY UVLO AND FAULT 15 DETECT MUX 6-BIT LINEAR DAC 6 OSCILATOR OSC OSC SELECT/ 24 DIVIDER CLOCK 11 SERIAL DATA 12 PORT STROBE 10 SLEEP BUFFER REF 13 6-BIT LINEAR ...
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A3973 ELECTRICAL CHARACTERISTICS < 50 kHz (unless otherwise noted). PWM Characteristic Load Supply Voltage Range Logic Supply Voltage Range Load Supply Current Logic Supply Current Output Drivers Output Leakage Current Output On Resistance Body Diode Forward Voltage ...
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A3973 ELECTRICAL CHARACTERISTICS < 50 kHz (unless otherwise noted). PWM Characteristics Control Logic (continued) Internal Oscillator DAC Accuracy (total error) Reference Input Voltage Range Reference Buffer Offset Reference Divider Ratio Reference Input Current Internal Reference Voltage Gain ...
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... A3973 Serial Interface. The A3973SB/SLB is controlled via a 3-wire (clock, data, strobe) serial port. The programmable func- tions allow maximum flexibility in configuring the PWM to the motor drive requirements. The serial data is written as two 19-bit words: 1 bit to select the word and 18 bits of data. The serial data is clocked in starting with D18. ...
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A3973 Word 1 Bit Assignments Bit Function D0 Word select = 1 D1 Blank-time LSB D2 Blank-time MSB D3 Off-time LSB D4 Off-time bit 1 D5 Off-time bit 2 D6 Off-time bit 3 D7 Off-time MSB D8 Fast-decay time LSB ...
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... V the drivers and resets the data in the serial port to zeros. Synchronous Rectification. When a PWM off-cycle is triggered, either by a bridge disable command or internal fixed off-time cycle, the load current will recirculate according to the decay mode selected by the control logic. The A3973SB/SLB ) synchronous rectification feature will turn on the appropriate S MOSFET(s) during the current decay and effectively short out ...
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A3973 Current Sensing. To minimize inaccuracies in sensing the I current level caused by ground-trace IR drops, the sense PEAK resistor should have an independent ground return to the ground terminal of the device. For low-value sense resistors, the IR drops in the sense resistor’s PCB traces can be significant and should be taken into account. The use ...
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A3973 1.27 MIN +0.25 1.52 –0.38 0.018 0.46 ±0.12 15.40±0. 24X 0.10 C 0.41 ±0.10 1.27 For reference only Pins 6 and 7, and 18 and 19 internally fused Dimensions in millimeters ...