2927 DUAL FULL-BRIDGE PWM MOTOR DRIVER GND LOGIC SUPPLY 40 PWM 1 GND 37 1 36 11 35 12 34 13 U D VBB 33 14 2 For PWM current control, the maximum output current is determined by the user’s selection of a reference voltage and sensing resistor. Two logic-level inputs select output current limits of 0, 33%, 67%, or 100% of the maximum level. A PHASE input to each bridge determines load current direction. Active-low ENABLE inputs control the four drivers in each bridge. T C 38 9 10 32 15 31 Y L N Internally generated delays prevent cross-over currents when switching current direction. Special power-up sequencing is not required. Thermal protection circuitry disables the outputs if the chip temperature exceeds safe operating limits. O R P EO D C E N U E N R I E T F N E O R C R S I O D F — 30 16 PWM 2 29 28 RC 2 27 ENABLE 2 26 V REF 2 25 PHASE 2 I21 24 I20 23 OUT 2B 21 LOAD SUPPLY 22 SENSE 2 20 E2 19 OUT 2A 18 GND EN 2 17 θ2 GND The A2927SEB motor driver is designed to drive both windings of a bipolar stepper motor or bidirectionally control two dc motors. Both bridges are capable of sustaining 50 V and include internal pulse-width modulation (PWM) control of the output current to 1.5 A. 39 7 8 DUAL FULL-BRIDGE PWM MOTOR DRIVER VCC ENABLE 1 RC1 41 PHASE 1 43 42 EN1 θ1 I11 2 VREF 1 3 1 OUT 1B I10 4 44 SENSE 1 5 1 OUT 1A E 6 PRELIMINARY INFORMATION (Subject to change without notice) September 16, 1997 Data Sheet 29319.23 2927 Dwg. PP-021 ABSOLUTE MAXIMUM RATINGS at TJ ≤ +150°C Motor Supply Voltage, VBB ................... 50 V Output Current, IOUT ......................... ±1.5 A Logic Supply Voltage, VCC ................... 7.0 V Logic Input Voltage Range, VIN ............................... -0.3 V to +7.0 V Output Emitter Voltage, VE .................. 1.0 V Package Power Dissipation, PD ........................................ See Graph Operating Temperature Range, TA ................................. -20°C to +85°C Storage Temperature Range, TS ............................... -55°C to +150°C The A2927SEB is supplied in a 44-lead power PLCC for surfacemount applications. Its batwing construction provides for maximum package power dissipation in the smallest possible construction. FEATURES ■ 1.5 A Output Current ■ 50 V Output Sustaining Voltage ■ Internal Flyback Diodes ■ Digital Control of Output Current ■ Undervoltage Lockout ■ Internal Thermal Shutdown Circuitry Output current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do not exceed the specified peak current rating or a junction temperature of +150°C. Always order by complete part number: A2927SEB . 2927 DUAL FULL-BRIDGE PWM MOTOR DRIVER PWM CURRENT-CONTROL CIRCUITRY VBB CHANNEL 1 PIN NUMBERS SHOWN. 22 OUT A OUT 6 B 3 V REF 44 5 20 kΩ ÷10 E SENSE – 4 40 kΩ RC 10 kΩ I0 2 R I1 1 ONE SHOT + S SOURCE DISABLE 41 RC CC R C T T Dwg. EP-007-4 12.5 T R θJ =6 10 /W °C ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS TRUTH TABLE Enable Phase OutA OutB L L H H L X H L Z L H Z X = Don’t care Z = High impedance 7.5 5.0 2.5 R θJA = 35 °C/W 0 25 50 75 100 TEMPERATURE IN °C 125 150 Dwg. GP-020-1 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1997 Allegro MicroSystems, Inc. 2927 DUAL FULL-BRIDGE PWM MOTOR DRIVER ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 50 V, VCC = 5.0 V, VREF = 5.0 V (unless otherwise noted). Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Output Drivers (OUTA or OUTB) Motor Supply Range VBB IOUT = ±1.5 A, L = 15 mH 10 — 50 V Output Leakage Current ICEX VOUT = VBB — <1.0 5.0 µA VOUT = 0 — <-1.0 -5.0 µA Sink Driver, IOUT = +1.0 A* — 0.5 0.7 V Sink Driver, IOUT = +1.5 A* — 0.8 0.9 V Source Driver, IOUT = -1.0 A* — 1.8 1.9 V Source Driver, IOUT = -1.5 A* — 1.9 2.0 V Output Saturation Voltage VCE(SAT) Flyback Diode Forward Volt. VF IF = 1.5 A — 1.6 2.0 V Driver Supply Current IBB(ON) Both Bridges ON, No Load — 6.5 9.0 mA IBB(OFF) Both Bridges OFF — 4.0 4.0 mA VIN(1) All Inputs 2.4 — — V VIN(0) All Inputs — — 0.8 V IIN(1) VIN = 2.4 V — <1.0 20 µA IIN(0) VIN = 0.8 V — -3.0 -200 µA Reference Voltage Range VREF Operating 1.5 — 7.5 V Current Limit Threshold VREF/VSENSE I0 = I1 = 0.8 V 9.5 10 10.5 — I0 = 2.4 V, I1= 0.8 V 13.5 15 16.5 — I0 = 0.8 V, I1 = 2.4 V 25.5 30 34.5 — — 170 — °C Control Logic Input Voltage Input Current (at trip point) Thermal Shutdown Temp. TJ Total Logic Supply Current ICC(ON) I0 = I1 = VEN = 0.8 V, No Load — 90 105 mA ICC(OFF) I0 = I1 = 2.4 V, No Load — 10 12 mA Negative current is defined as coming out of (sourcing) the specified device pin. Typical Data is for design information only. * Pulse test (<10 ms). 2927 DUAL FULL-BRIDGE PWM MOTOR DRIVER APPLICATIONS INFORMATION PWM OUTPUT CURRENT WAVEFORM PWM CURRENT CONTROL: The UDN2927EB dual bridge is designed to drive both windings of a bipolar stepper motor. Output current is sensed and controlled independently in each bridge by an external sense resistor (RS ), internal comparator, and monostable multivibrator. When the bridge is turned ON, current increases in the motor winding and it is sensed by the external sense resistor until the sense voltage (VSENSE) reaches the level set at the comparator’s input: V PHASE + I OUT 0 – I TRIP ITRIP = VREF/10 RS The comparator then triggers the monostable which turns OFF the source driver of the bridge. The actual load current peak will be slightly higher than the trip point (especially for low-inductance loads) because of the internal logic and switching delays. This delay (td) is typically 2 µs. After turn-off, the motor current will normally decay, circulating through the external ground clamp diode and sink transistor. The source driver’s OFF time (and therefore the magnitude of the current decrease) is determined by the monostable’s external RC timing components, where toff = RTCT within the range of 20 kΩ to 100 kΩ and 200 pF to 500 pF. td t off Dwg. WM-003-1A LOAD CURRENT PATHS V BB When the source driver is re-enabled, the winding current (the sense voltage) is again allowed to rise to the comparator’s threshold. This cycle repeats itself, maintaining the average motor winding current at the desired level. Special circuitry has been included to prevent runaway current control when the fixed OFF time (toff) is set too short. This circuitry prevents the source driver from being re-enabled until the load current has decayed to below the ITRIP level. RS BRIDGE ON SOURCE OFF ALL OFF Dwg. EP-006-14 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 2927 DUAL FULL-BRIDGE PWM MOTOR DRIVER CURRENT-CONTROL TRUTH TABLE I0 I1 Output Current L L VREF /10 RS = ITRIP H L VREF /15 RS = 2/3 ITRIP L H VREF /30 RS = 1/3 ITRIP H H 0 Loads with high distributed capacitances may result in high turn-ON current peaks. This peak (appearing across RS ) will attempt to trip the comparator, resulting in erroneous current control or high-frequency oscillations. An external RCCC low-pass filter may be needed to delay the action of the comparator. LOGIC CONTROL OF OUTPUT CURRENT: Two logic level inputs (I0 and I1) allow digital selection of the motor winding current at 100%, 67%, 33%, or 0% of the maximum level per the table. The 0% output current condition turns OFF all drivers in the bridge and can be used as an output enable function. These logic level inputs greatly enhance the implementation of µP-controlled drive formats. During half-step operations, the I0 and I1 inputs allow the µP to control the motor at a constant torque between all positions in an eight-step sequence. This is accomplished by digitally selecting 100% drive current when only one phase is ON and 67% drive current when two phases are ON. The logic control inputs can also be used to select a reduced current level (and reduced power dissipation) for ‘hold’ conditions and/or increased current (and available torque) for start-up conditions. GENERAL: Both bridges have internal flyback diodes (connected from the outputs to VBB) for protection against inductive transients. External ground-clamp diodes (connected from the outputs to ground) are required; Schottky ground-clamp diodes are recommended to minimize onchip power dissipation. To avoid excessive voltage spikes on the LOAD SUPPLY terminal (VBB), a large-value capacitor (≥47 µF) should be connected from VBB to ground as close as possible to the device. Under no circumstances should the voltage at LOAD SUPPLY exceed 50 V. A low-value (0.1 µF) ceramic capacitor at this terminal may be used for high-frequency noise suppression. The PHASE input to each bridge determines the direction motor winding current flows. An internally generated deadtime (approximately 3 µs) prevents crossover currents that can occur when switching the PHASE input. All four drivers in the bridge output can be turned OFF (VEN ≥ 2.4 V or I0 = I1 ≥ 2.4 V), resulting in a fast current decay through the internal flyback and external groundclamp diodes. The fast current decay is desirable in halfstep and high-speed applications. All logic inputs float high; the ENABLE input must be tied low if it is not used. Varying the reference voltage (VREF) provides continuous control of the peak load current for micro-stepping applications, within the specified limits for VREF. Thermal protection circuitry turns OFF all drivers when the junction temperature reaches approximately +170°C. It is only intended to protect the device from failures due to excessive junction temperature and should not imply that output short circuits are permitted. The output drivers are reenabled when the junction temperature cools to approximately +160°C. 2927 DUAL FULL-BRIDGE PWM MOTOR DRIVER Dimensions in Inches (controlling dimensions) 18 28 29 17 0.032 0.026 0.319 0.291 0.695 0.685 0.021 0.013 0.656 0.650 0.319 0.291 0.050 INDEX AREA BSC 39 7 40 0.020 44 1 2 6 0.656 0.650 MIN 0.695 0.685 0.180 0.165 Dwg. MA-005-44A in Dimensions in Millimeters (for reference only) 18 28 29 17 0.812 0.661 8.10 7.39 17.65 17.40 0.533 0.331 16.662 16.510 8.10 7.39 INDEX AREA 1.27 BSC 7 39 40 0.51 MIN 4.57 4.20 44 1 2 6 16.662 16.510 17.65 17.40 Dwg. MA-005-44A mm NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown. 2. Lead spacing tolerance is non-cumulative. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 2927 DUAL FULL-BRIDGE PWM MOTOR DRIVER This page intentionally left blank 2927 DUAL FULL-BRIDGE PWM MOTOR DRIVER BRIDGE & HALF-BRIDGE DRIVERS SELECTION GUIDE IN ORDER OF 1) OUTPUT CURRENT AND 2) OUTPUT VOLTAGE Features Output Ratings * Internal Diodes Outputs Internal Protection Dual PWM Full Bridge Dual PWM Full Bridge X X Bipolar Bipolar X X 3966 3968 45 45 45 Dual PWM Full Bridge Dual PWM Full Bridge Dual PWM Full Bridge X X X Bipolar Bipolar Bipolar X X X 2916 2919 6219 ±800 33 Dual PWM Full Bridge X Bipolar X 3964 ±900 14 3-Ø Back-EMF Controller/Driver X DMOS X 8902-A ±1000 7.0 3-Ø Back-EMF Controller/Driver X NMOS X 8984 ±1300 50 PWM Full Bridge X Bipolar X 3953 ±1500 45 45 50 50 Dual PWM Full Bridge Dual PWM Full Bridge PWM Microstepping Full Bridge PWM Microstepping Full Bridge X X X X Bipolar Bipolar Darlington/Satlington™ Darlington/Satlington™ X X X X 2917 2918 3955 3957 ±2000 45 50 50 50 3-Ø Brushless Controller/Driver Dual Full Bridge PWM Full-Bridge PWM Full-Bridge X X X X Darlington Darlington Darlington Darlington X X X X 2936 2998 3951 3952 ±3000 45 PWM Control X Darlington – 2962 ±3400 45 PWM Control X Bipolar X 2961 ±4000 14 3-Ø Brushless Controller/Driver X DMOS X 8925 mA V Description ±650 30 30 ±750 Part Number † * Current is maximum specified test condition, voltage is maximum rating. See specification for sustaining voltage limits or overcurrent protection voltage limits. † Complete part number includes additional characters to indicate operating temperature range and package style. Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the design of its products. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000