A3973SB

A3973SB Datasheet

A3973 Dual DMOS Full-Bridge Microstepping PWM Motor Driver

Part	Datasheet
A3973SB	A3973SB (pdf)

Related Parts	Information
A3973SB-T	A3973SB-T
A3973SLB-T	A3973SLB-T
A3973SLBTR-T	A3973SLBTR-T
A3973SLB	A3973SLB
A3973SLBTR	A3973SLBTR

PDF Datasheet Preview
A3973 Dual DMOS Full-Bridge Microstepping PWM Motor Driver ±1 A, 35 V Continuous Output Rating Low RDS on DMOS Output Drivers 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 or 5 V Control Signals Sleep and Idle Modes Packages: Package B, 24-pin DIP with two batwing power tabs Not to scale Package LB, 24 pin SOICW with 4 fused leads Designed for pulse-width modulated PWM current control of bipolar microstepping stepper motors, the A3973 is capable of continuous output currents to ±1 A and operating voltages to 35 V. Internal fixed off-time PWM current-control timing circuitry can be programmed via a serial interface to operate in slow, fast, and mixed current-decay modes. The desired load-current level is set via the serial port with two 6-bit linear DACs in conjunction with a reference voltage. The six bits of control allow maximum flexibility in torque control for a variety of step methods, from microstepping to full-step drive. Load current is set in increments of the maximum value. Synchronous rectification circuitry allows the load current to flow through the low RDS on of the DMOS output driver during the current decay. This feature eliminates the need for external clamp diodes in most applications, saving cost and external component count, while minimizing power dissipation. Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover-current protection. Special power-up sequencing is not required. The B package is a 24-lead DIP with two copper batwing power tabs. The LB is a 24-lead SOICW with four internally fused leads for enhanced power dissipation. These power tabs and pins are at ground potential and need no electrical isolation. The A3973 B and LB packages are electrically identical. Pin-out Diagram VCP 1 CP1 2 CP2 3 OUT 1B 4 LOAD SUPPLY 1 5 V BB1 GROUND 6 GROUND 7 SENSE 1 8 OUT 1A 99 STROBE 10 CLOCK 11 DATA 12 CHARGE PUMP SERIAL PORT 6-BIT DAC & LOGIC 6-BIT DAC & LOGIC 24 OSC 23 SLEEP 22 V REG 21 OUT 2B 20 LOAD V BB2 SUPPLY 2 19 GROUND 18 GROUND 17 SENSE 2 16 OUT 2A LOGIC VDD 15 SUPPLY 14 MUX 13 REF Dwg. PP-069-3 A3973 Dual DMOS Full-Bridge Microstepping PWM Motor Driver Selection Guide Package A3973SB-T 24 pin DIP with two power tabs A3973SLB-T 24 pin SOICW with four internally fused pins A3973SLBTR-T 24 pin SOICW with four internally fused pins Packing 15 pieces per tube 31 pieces per tube 1000 pieces per reel

PDF Datasheet Preview

A3973 Dual DMOS Full-Bridge Microstepping PWM Motor Driver
±1 A, 35 V Continuous Output Rating Low RDS on DMOS Output Drivers 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 or 5 V Control Signals Sleep and Idle Modes

Packages:

Package B, 24-pin DIP with two batwing power tabs

Not to scale

Package LB, 24 pin SOICW with 4 fused leads

Designed for pulse-width modulated PWM current control of bipolar microstepping stepper motors, the A3973 is capable of continuous output currents to ±1 A and operating voltages to 35 V. Internal fixed off-time PWM current-control timing circuitry can be programmed via a serial interface to operate in slow, fast, and mixed current-decay modes.

The desired load-current level is set via the serial port with two 6-bit linear DACs in conjunction with a reference voltage. The six bits of control allow maximum flexibility in torque control for a variety of step methods, from microstepping to full-step drive. Load current is set in increments of the maximum value.

Synchronous rectification circuitry allows the load current to flow through the low RDS on of the DMOS output driver during the current decay. This feature eliminates the need for external clamp diodes in most applications, saving cost and external component count, while minimizing power dissipation.

Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover-current protection. Special power-up sequencing is not required.

The B package is a 24-lead DIP with two copper batwing power tabs. The LB is a 24-lead SOICW with four internally fused leads for enhanced power dissipation. These power tabs and pins are at ground potential and need no electrical isolation. The A3973 B and LB packages are electrically identical.

Pin-out Diagram

VCP 1 CP1 2 CP2 3 OUT 1B 4 LOAD SUPPLY 1 5 V BB1 GROUND 6 GROUND 7 SENSE 1 8 OUT 1A 99 STROBE 10 CLOCK 11 DATA 12

CHARGE PUMP

SERIAL PORT
6-BIT DAC & LOGIC 6-BIT DAC & LOGIC
24 OSC
23 SLEEP
22 V REG
21 OUT 2B
20 LOAD

V BB2

SUPPLY 2
19 GROUND
18 GROUND
17 SENSE 2 16 OUT 2A

LOGIC VDD 15 SUPPLY
14 MUX
13 REF

Dwg. PP-069-3

A3973

Dual DMOS Full-Bridge Microstepping PWM Motor Driver

Selection Guide

Package

A3973SB-T
24 pin DIP with two power tabs

A3973SLB-T
24 pin SOICW with four internally fused pins

A3973SLBTR-T
24 pin SOICW with four internally fused pins

Packing 15 pieces per tube 31 pieces per tube 1000 pieces per reel

Notice: we do not provide any warranties that information, datasheets, application notes, circuit diagrams, or software stored on this website are up-to-date or error free. The archived A3973SB Datasheet file may be downloaded here without warranties.

Datasheet ID: A3973SB 516031