3952
FULL-BRIDGE PWM MOTOR DRIVER
A3952SB
BRAKE REF RC GROUND GROUND LOGIC SUPPLY PHASE ENABLE 1 2 3 4 LOGIC 5 6 7 8 VBB VCC 12 11 10 9 GROUND SENSE OUTA LOAD SUPPLY VBB 16 15 14 13 LOAD SUPPLY OUTB MODE GROUND
Data Sheet 29319.1*
Designed for bidirectional pulse-width modulated current control of inductive loads, the A3952S– is capable of continuous output currents to ±2 A and operating voltages to 50 V. Internal fixed off-time PWM current-control circuitry can be used to regulate the maximum load current to a desired value. The peak load current limit is set by the user’s selection of an input reference voltage and external sensing resistor. The fixed OFF-time pulse duration is set by a user-selected external RC timing network. Internal circuit protection includes thermal shutdown with hysteresis, transient suppression diodes, and crossovercurrent protection. Special power-up sequencing is not required. With the ENABLE input held low, the PHASE input controls load current polarity by selecting the appropriate source and sink driver pair. The MODE input determines whether the PWM current-control circuitry operates in a slow current-decay mode (only the selected sink driver switching) or in a fast current-decay mode (selected source and sink switching). A user-selectable blanking window prevents false triggering of the PWM current control circuitry. With the ENABLE input held high, all output drivers are disabled. A sleep mode is provided to reduce power consumption when inactive. When a logic low is applied to the BRAKE input, the braking function is enabled. This overrides ENABLE and PHASE to turn OFF both source drivers and turn ON both sink drivers. The brake function can be safely used to dynamically brake brush dc motors. The A3952S– is supplied in a choice of four power packages. In all package styles, the batwing/power tab is at ground potential and needs no isolation. These devices are also available for operation from -40°C to +125°C. To order, change the suffix from 'S–' to 'K–'.
Dwg. PP-056
Note that the A3952SB (DIP) and the A3952SLB (SOIC) are electrically identical and share a common terminal number assignment.
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, VBB .................. 50 V Output Current, IOUT (tw ≤ 20 µs) .................................. ±3.5 A (Continuous) ............................... ±2.0 A Logic Supply Voltage, VCC ................. 7.0 V Logic Input Voltage Range, VIN ....................... -0.3 V to VCC + 0.3 V Sense Voltage, VSENSE ...................... 1.5 V Reference Voltage, VREF .................... 15 V Package Power Dissipation, PD ....................................... See Graph Operating Temperature Range, TA ............................... –20°C to +85°C Junction Temperature, TJ ............. +150°C* Storage Temperature Range, TS ............................. –55°C to +150°C
Output current rating may be limited by duty cycle, ambient temperature, heat sinking and/or forced cooling. Under any set of conditions, do not exceed the specified current rating or a junction temperature of +150° C. * Fault conditions that produce excessive junction temperature will activate device thermal shutdown circuitry. These conditions can be tolerated but should be avoided.
FEATURES
s s s s s s s s s ±2 A Continuous Output Current Rating 50 V Output Voltage Rating Internal PWM Current Control Fast and Slow Current-Decay Modes Sleep (Low Current Consumption) Mode Internal Transient Suppression Diodes Under-Voltage Lockout Internal Thermal Shutdown Circuitry Crossover-Current Protection
Always order by complete part number: Part Number A3952SB A3952SEB A3952SLB A3952SW Package 16-Pin DIP 28-Lead PLCC 16-Lead SOIC 12-Pin Power-Tab SIP RθJA 43°C/W 42°C/W 67°C/W 36°C/W Rθ JT 6.0° C/W 6.0° C/W 6.0° C/W 2.0° C/W
3952 FULL-BRIDGE PWM MOTOR DRIVER
FUNCTIONAL BLOCK DIAGRAM
LOAD SUPPLY OUTA OUTB
MODE PHASE UVLO & TSD EMITTERS
'EB' ONLY
ENABLE
BRAKE LOGIC SUPPLY REF 1.5 V 9R VCC
R Q
BLANKING
S
PWM LATCH
+–
R GROUND
VTH RT
TRUTH TABLE
10
ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS
'W' TAB 'B' , 'EB', & 'LB' TAB
BRAKE ENABLE PHASE H H H H H H L L L L X X
X = Irrelevant NOTES:
MODE H L H L H L H L
8
X X H H L L X X
6
H
'W' AMBIENT
4
'B' & 'EB' AMBIENT 'LB' AMBIENT
H L L
2
0
25
50
75
100
125
Dwg. GP-007-1A
150
TEMPERATURE IN °C
Z = High Impedance (source and sink both OFF)
1. Includes active pull-offs for power outputs. 2. Includes internal default Vsense level for over-current protection. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1994 Allegro MicroSystems, Inc.
– +
VCC
INPUT LOGIC
VBB
SLEEP & STANDBY MODES
SENSE
'B', 'LB', & 'W' PACKAGES
RS RC
CT
Dwg. FP-036
OUTA Z Z H H L L L L
OUTB Z Z L L H H L L
DESCRIPTION Sleep Mode Standby, Note 1 Forward, Fast-Decay Mode Forward, Slow-Decay Mode Reverse, Fast-Decay Mode Reverse, Slow-Decay Mode Brake, Fast-Decay Mode Brake, No Current Control, Note 2
3952 FULL-BRIDGE PWM MOTOR DRIVER
NO CONNECTION
A3952SEB
LOAD SUPPLY BRAKE MODE RC OUT B REF
A3952SW
28
27
26
3
4
2
1
GROUND
5 6 7 8 9 10 VBB LOGIC
25 24 23 22 21 20 19 VCC
GROUND
VBB
GROUND
11
GROUND
1
13 16 12 15 17 14 18
2
OUTB
3
LOAD SUPPLY
4
BRAKE
5
REF
6
RC
7
LOGIC SUPPLY
VCC
LOGIC
8
PHASE
9
ENABLE
10
MODE
11
OUTA
12
SENSE
EMITTERS
LOGIC SUPPLY
Dwg. PP-057
GROUND
LOAD SUPPLY
ENABLE
PHASE
OUTA
SENSE
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 50 V, VCC = 5.0 V, VBRAKE = 2.0 V, VSENSE = 0 V, RC = 20 kΩ/1000 pF to Ground (unless noted otherwise).
Limits Characteristic Output Drivers Load Supply Voltage Range Output Leakage Current VBB ICEX Operating, IOUT = ±2.0 A, L = 3 mH VOUT = V BB VOUT = 0 V Output Saturation Voltage VCE(SAT) Source Driver, IOUT = -0.5 A Source Driver, IOUT = -1.0 A Source Driver, IOUT = -2.0 A Sink Driver, IOUT = +0.5 A Sink Driver, IOUT = +1.0 A Sink Driver, IOUT = +2.0 A Clamp Diode Forward Voltage (Source or Sink) VF IF = 0.5 A IF = 1.0 A IF = 2.0 A Load Supply Current (No Load) IBB(ON) IBB(OFF) VENABLE = 0.8 V VENABLE = 2.0 V, VMODE = 0.8 V VBRAKE = 0.8 V IBB(SLEEP) VENABLE = VMODE = 2.0 V VCC – – – – – – – – – – – – – – – –