A3972SB Allegro Microsystems Inc, A3972SB Datasheet
A3972SB
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A3972SB Summary of contents
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... Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover-current protection. Special power-up sequencing is not required. The A3972SB is supplied in a 24-pin plastic DIP with two batwing power tabs (suffix ‘B’). The power tabs are at ground potential and need no electrical isolation. The device is lead (Pb) free with 100% matte tin leadframe plating ...
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... A3972 Selection Guide Part Number A3972SB-T 15 pieces/tube Absolute Maximum Ratings Characteristic Load Supply Voltage Output Current* Logic Supply Voltage Logic Input Voltage Range Reference Voltage Sense Voltage (DC) Package Power Dissipation Operating Ambient Temperature Junction Temperature Storage Temperature *Output current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do not exceed the specifi ...
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A3972 LOGIC SUPPLY UVLO AND FAULT 15 V DETECT DD MUX 14 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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A3972 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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A3972 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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... A3972 Serial Interface. The A3972SB is controlled via a 3-wire (clock, data, strobe) serial port. The programmable functions allow maximum fl exibility in confi guring 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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A3972 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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... If the fast-decay time is set longer than the off-time, the device effectively operates in fast-decay mode. Oscillator. The PWM timer is based on an oscillator input, typically 4 MHz. The A3972SB can be confi gured to select ei- ther a 4 MHz internal oscillator or, if more precision is required, an external clock can be connected to the OSC terminal external clock is used, three internal divider choices are select- able via the serial port to allow fl ...
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A3972 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 ...
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A3972 0.005 0.060 0.018 Copyright ©2000-2007, Allegro MicroSystems, Inc. The products described here are manufactured under one or more U.S. patents or U.S. patents pending. Allegro MicroSystems, Inc. reserves the right to make, from time to ...