A3967 Microstepping Driver with Translator Features and Benefits Description 750 mA, 30 V output rating The A3967 is a complete microstepping motor driver with built- Satlington sink drivers in translator. It is designed to operate bipolar stepper motors in Automatic current-decay mode detection/selection full-, half-, quarter-, and eighth-step modes, with output drive 3.0 to 5.5 V logic supply voltage range capability of 30 V and 750 mA. The A3967 includes a fixed Mixed, fast, and slow current-decay modes off-time current regulator that has the ability to operate in slow, Internal UVLO and thermal shutdown circuitry fast, or mixed current-decay modes. This current-decay control Crossover-current protection scheme results in reduced audible motor noise, increased step accuracy, and reduced power dissipation. The translator is the key to the easy implementation of the A3967. By simply inputting one pulse on the STEP input the motor will take one step (full, half, quarter, or eighth depending Package: 24-pin SOIC with internally on two logic inputs). There are no phase-sequence tables, high- fused pins (suffix LB) frequency control lines, or complex interfaces to program. The A3967 interface is an ideal fit for applications where a complex P is unavailable or over-burdened. Internal circuit protection includes thermal shutdown with hysteresis, under-voltage lockout (UVLO) and crossover- current protection. Special power-up sequencing is not required. The A3967 is supplied in a 24-pin SOIC, which is lead (Pb) free with 100% matte tin leadframe plating. Four pins are fused internally for enhanced thermal dissipation. The pins Not to scale are at ground potential and need no insulation. Functional Block Diagram LOGIC LOAD SUPPLY SUPPLY UVLO VCC AND 14 FAULT REF. DETECT SUPPLY VBB1 20 REF 1 8 DAC SENSE +- RC1 OUT1A PWM LATCH 23 BLANKING 16 MIXED DECAY OUT1B 21 PWM TIMER 3 10 STEP DIR SENSE1 11 17 RESET 22 MS1 12 MS2 13 5 VBB2 3 SLEEP ENABLE 15 VPF OUT2A 9 24 PWM TIMER OUT2B PFD 3 4 PWM LATCH BLANKING MIXED DECAY 2 RC2 +- SENSE2 DAC 8 6 7 18 19 Dwg. FP-050-3A 26184.24H TRANSLATOR CONTROL LOGICA3967 Microstepping Driver with Translator Selection Guide Part Number Packing Package A3967SLBTR-T 24-pin SOIC with internally fused pins 1000 per reel Absolute Maximum Ratings Characteristic Symbol Notes Rating Units Load Supply Voltage V 30 V BB Logic Supply Voltage V 7.0 V CC t > 30 ns 0.3 to 7.0 V w Logic Input Voltage Range V IN t < 30 ns 1 to 7.0 V w Sense Voltage V 0.68 V SENSE Reference Voltage V V mA REF CC Output current rating may be limited by duty cycle, am- Continuous 750 mA bient temperature, and heat sinking. Under any set of Output Current I OUT conditions, do not exceed the speci ed current rating Peak 850 mA or a junction temperature of 150C. Package Power Dissipation P See graph D Operating Ambient Temperature T Range S 20 to 85 C A Fault conditions that produce excessive junction temperature will activate Maximum Junction Temperature T (max) the devices thermal shutdown circuitry. These conditions can be toler- 150 C J ated but should be avoided. Storage Temperature T 55 to 150 C stg Thermal Characteristics Characteristic Symbol Test Conditions* Value Units 2 2-layer PCB, 1.3 in. 2-oz. exposed copper 50 C/W Package Thermal Resistance, Junction R JA to Ambient 4-layer PCB, based on JEDEC standard 35 C/W *Additional thermal information available on Allegro website. 5 R = 6.0o C/W Q JT 4 3 R = 35C/W Q JA 2 R = 50C/W Q JA 1 0 25 50 75 100 125 150 TEMPERATURE IN o C Allegro MicroSystems, LLC 2 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000 www.allegromicro.com ALLOWABLE PACKAGE POWER DISSIPATION (W)