A3982SLB-T

A3982 DMOS Stepper Motor Driver with Translator Features and Benefits Description ▪ Low RDS(on) outputs ▪ Automatic current decay mode detection/selection ▪ Mixed and Slow current decay modes ▪ Synchronous rectification for low power dissipation ▪ Internal UVLO and thermal shutdown circuitry ▪ Crossover-current protection The A3982 is a complete stepper motor driver with builtin translator for easy operation. It is designed to operate bipolar stepper motors in full- and half-step modes, with an output drive capacity of up to 35 V and ±2 A. The A3982 includes a fixed off-time current regulator which has the ability to operate in Slow or Mixed decay modes. The translator is the key to the easy implementation of the A3982. Simply inputting one pulse on the STEP input drives the motor one step. There are no phase sequence tables, high frequency control lines, or complex interfaces to program. The A3982 interface is an ideal fit for applications where a complex microprocessor is unavailable or is overburdened. The chopping control in the A3982 automatically selects the current decay mode (Slow or Mixed). When a signal occurs at the STEP input pin, the A3982 determines if that step results in a higher or lower current in each of the motor phases. If the change is to a higher current, then the decay mode is set to Slow decay. If the change is to a lower current, then the current decay is set to Mixed (set initially to a fast decay for a period amounting to 31.25% of the Package: 24 pin SOICW with internally fused leads (suffix LB) Continued on the next page… Not to scale Pin-out Diagram OUT2A 1 24 OUT1A SENSE2 2 23 SENSE1 22 VBB1 4 21 OUT1B ENABLE 5 20 DIR PGND 6 PGND 7 CP1 8 CP2 9 MS1 12 26184.28C 19 PGND 18 PGND 17 REF 16 STEP 15 VDD OSC VREG 11 Reg VCP 10 Translator & Control Logic 3 Charge Pump VBB2 OUT2B 14 ROSC 13 RESET A3982 DMOS Stepper Motor Driver with Translator Description (continued) fixed off-time, then to a slow decay for the remainder of the off-time). This current decay control scheme results in reduced audible motor noise, increased step accuracy, and reduced power dissipation. Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation. Internal circuit protection includes: thermal shutdown with hysteresis, undervoltage lockout (UVLO), and crossover-current protection. Special power-on sequencing is not required. The A3982 is supplied in a 24-pin wide-body SOIC (package LB) with internally-fused power ground leads for enhanced thermal dissipation. It is lead (Pb) free, with 100% matte tin plated leadframe. Selection Guide Part Number Packing* A3982SLB-T 31 pieces per tube A3982SLBTR-T 1000 pieces per reel Package 24-pin Wide SOIC with pins 6 and 7, and 18 and 19, fused internally *Contact Allegro for additional packing options Absolute Maximum Ratings Rating Units Load Supply Voltage Characteristic VBB 35 V Logic Input Voltage VIN –0.3 to 7 V Sense Voltage Symbol Notes VSENSE 0.5 V Reference Voltage VREF 4 V Output Current IOUT ±2 A –20 to 85 ºC Output current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do not exceed the specified current rating or a junction temperature of 150°C. Range S Operating Ambient Temperature TA Maximum Junction Temperature TJ(max) 150 ºC Tstg –55 to 150 ºC Storage Temperature Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 A3982 DMOS Stepper Motor Driver with Translator Functional Block Diagram 0.1 μF 0.22 μF VREG VDD Current Regulator ROSC CP1 CP2 Charge Pump OSC VCP 0.1 μF REF DMOS Full Bridge DAC VBB1 OUT1A OUT1B PWM Latch Blanking Mixed Decay STEP DIR RESET SENSE1 Gate Drive Translator MS1 Control Logic DMOS Full Bridge RS1 VBB2 OUT2A OUT2B PWM Latch Blanking Mixed Decay ENABLE SENSE2 RS2 DAC VREF Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3 A3982 DMOS Stepper Motor Driver with Translator ELECTRICAL CHARACTERISTICS1 at TA = 25°C, VBB = 35 V (unless otherwise noted) Characteristics Output Drivers Load Supply Voltage Range Logic Supply Voltage Range Output On Resistance Min. Typ.2 Max. Units 8 3.0 – – – – – – – – – – 0.370 0.330 – – – – – – 35 5.5 0.460 0.380 1.2 1.2 4 2 8 5 V V Ω Ω V V mA mA mA mA VIN(1) VDD0.7 – – V VIN(0) – – V μA Symbol VBB VDD RDSON Body Diode Forward Voltage VF Motor Supply Current IBB Logic Supply Current IDD Test Conditions Operating Operating Source Driver, IOUT = –1.5 A Sink Driver, IOUT = 1.5 A Source Diode, IF = –1.5 A Sink Diode, IF = 1.5 A fPWM < 50 kHz Operating, outputs disabled fPWM < 50 kHz Outputs off Control Logic Logic Input Voltage Logic Input Current Input Hysteresis Blank Time IIN(1) IIN(0) VIN = VDD0.7 VIN = VDD0.3 VHYS(IN) tBLANK Fixed Off-Time tOFF Reference Input Voltage Range Reference Input Current VREF IREF Current Trip-Level Error3 errI Crossover Dead Time Protection Thermal Shutdown Temperature Thermal Shutdown Hysteresis UVLO Enable Threshold UVLO Hysteresis tDT OSC > 3 V ROSC = 25 kΩ VREF = 2 V, %ITripMAX = 70.71% VREF = 2 V, %ITripMAX = 100.00% TJ TJHYS UVLO UVHYS VDD rising –20