A4956 Datasheet, PDF (1/11 Pages) Allegro MicroSystems – Full-Bridge PWM Gate Driver

A4956
Full-Bridge PWM Gate Driver
FEATURES AND BENEFITS
• PHASE/ENABLE/MODE control logic
• Overcurrent indication
• Adjustable off-time and blank-time
• Adjustable current limit
• Adjustable gate drive
• Synchronous rectification
• Internal UVLO
• Crossover-current protection
• MOSFET VDS protection
• Voltage output proportional to load current
• Decay-mode selection for external PWM
• A4956K is AEC-Q100 Grade 1 qualified
• Commercial temperature grade (A4956G: –40°C to 105°C)
• Automotive temperature grade (A4956K: –40°C to 125°C)
PACKAGES:
20-Pin QFN (suffix “ES”)
with Exposed Thermal Pad
20-Pin eTSSOP (suffix “LP”)
with Exposed Thermal Pad
DESCRIPTION
Designed for pulse-width-modulated (PWM) control of DC
motors, the A4956 is capable of 50 V operation and provides
gate drive for an all n-channel external MOSFET bridge.
Input terminals are provided for use in controlling the speed and
direction of a DC motor with externally applied PWM control
signals. Internal synchronous rectification control circuitry is
provided to lower power dissipation during PWM operation.
Internal circuit protection includes VDS protection, thermal
shutdown with hysteresis, undervoltage monitoring of VBB,
and crossover-current protection.
The A4956 is supplied in a low-profile 4×4 mm, 20-contact
QFN package (suffix “ES”) and a 20-lead eTSSOP (suffix
“LP”), both with exposed thermal pad.
Not to scale
0.1 µF
System
Controller
A4956-DS, Rev. 1
optional
TSD
ISET
UVLO
RC
MODE
PHASE
ENABLE
OCLn
STANDBY
Control
Logic
OCL
Filter
AIOUT HOLD
×10
VREF
÷10
CHARGE PUMP
VREG
VCP
GATE
DRIVE
+
–
VCP
VBB
GHA
GHB
SB
SA
GLA
GLB
SENSE
GND
Functional Block Diagram
0.1 µF
VIN
GHA
SA
GLA
R_SENSE
Inrush current limit =
V_REF/10 * R_SENSE