Datenblatt-pdf.com


A4952 Schematic ( PDF Datasheet ) - Allegro

Teilenummer A4952
Beschreibung (A4952 / A4953) Full-Bridge DMOS PWM Motor Drivers
Hersteller Allegro
Logo Allegro Logo 




Gesamt 11 Seiten
A4952 Datasheet, Funktion
A4952 and A4953
Full-Bridge DMOS PWM Motor Drivers
Features and Benefits
• Low RDS(on) outputs
• Overcurrent protection (OCP)
Motor short protection
Motor lead short to ground protection
Motor lead short to battery protection
• Low Power Standby mode
• Adjustable PWM current limit
• Synchronous rectification
• Internal undervoltage lockout (UVLO)
• Crossover-current protection
• Fault output (A4952 only)
• Selectable retry (A4952 only)
Packages:
10-pin MSOP
with exposed thermal pad
(LY package)
Description
Designed for pulse width modulated (PWM) control of DC
motors, the A4952 and A4953 are capable of peak output
currents to ±2 A and operating voltages to 40 V.
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 overcurrent protection,
motor lead short to ground or supply, thermal shutdown with
hysteresis, undervoltage monitoring of VBB, and crossover-
current protection.
The A4952 is provided in a low-profile 10-pin MSOP package
(suffix LY) and the A4953 is provided in a low-profile
8-pin SOICN package (suffix LJ). Both packages have an
exposed thermal pad, and are lead (Pb) free, with 100% matte tin
leadframe plating.
8-pin SOICN
with exposed thermal pad
(LJ package)
Not to scale
Functional Block Diagram
A4952 only
RTRY
VINT
IN1
IN2
GND
A4952 only
FLTn
VREF
÷ 10
OSC
Charge
Pump
Control
Logic
Disable
TSD
UVLO
7V
Load Supply
VBB
OUT1
OUT2
LSS
(Optional)
A4952-DS, Rev. 2
Free Datasheet http://www.Datasheet4U.com






A4952 Datasheet, Funktion
A4952 and
A4953
Full-Bridge DMOS PWM Motor Drivers
Synchronous Rectification
When a PWM off-cycle is triggered by an internal fixed off-time
cycle, load current will recirculate. The A4952/A4953 synchro-
nous rectification feature turns-on the appropriate DMOSFETs
during the current decay, and effectively shorts out the body
diodes with the low RDS(on) driver. This significantly lowers
power dissipation. When a zero current level is detected, syn-
chronous rectification is turned off to prevent reversal of the load
current.
Mixed Decay Operation
The bridges operate in Mixed Decay mode. Referring to the
lower panel of the figure below, as the trip point is reached, the
device goes into fast decay mode for 50% of the fixed off-time
period. After this fast decay portion the device switches to slow
decay mode for the remainder of the off-time. During transitions
from fast decay to slow decay, the drivers are forced off for the
Crossover Delay, tCOD . This feature is added to prevent shoot-
through in the bridge. During this “dead time” portion, synchro-
nous rectification is not active, and the device operates in fast
decay and slow decay only.
Mixed Decay Mode Operation
VPHASE
+
IOUT 0
See Enlargement A
Enlargement A
Fixed Off-Time, toff = 25 μs
0.50 × toff
0.50 × toff
ITrip
IOUT
tCOD
Fast Decay
tCOD
Slow Decay
tCOD
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
6
Free Datasheet http://www.Datasheet4U.com

6 Page







SeitenGesamt 11 Seiten
PDF Download[ A4952 Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
A4950Full-Bridge DMOS PWM Motor DriverAllegro MicroSystems
Allegro MicroSystems
A4952(A4952 / A4953) Full-Bridge DMOS PWM Motor DriversAllegro
Allegro
A4953(A4952 / A4953) Full-Bridge DMOS PWM Motor DriversAllegro
Allegro

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche