A4952ELYTR-T Allegro Microsystems Inc, A4952ELYTR-T Datasheet - Page 7

• Manufacturer Part Number: A4952ELYTR-T
• Description: IC PWM MOTOR DVR FULL 10-MSOP
• Manufacturer: Allegro Microsystems Inc

Specifications of A4952ELYTR-T

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

A4952 and
A4953
Sense Pin (LSS)
In order to use PWM current control, a low-value resistor is
placed between the LSS pin and ground for current sensing pur-
poses. To minimize ground-trace IR drops in sensing the output
current level, the current sensing resistor should have an indepen-
dent ground return to the star ground point. This trace should be
as short as possible. For low-value sense resistors, the IR drops in
the PCB can be significant, and should be taken into account.
When selecting a value for the sense resistor be sure not to
exceed the maximum voltage on the LSS pin of ±500 mV at
maximum load. During overcurrent events, this rating may be
exceeded for short durations.
Ground
A star ground should be located as close to the A4952/ A4953
as possible. The copper ground plane directly under the exposed
Layout for the A4952 (LY package)
GND
GND
Bill of Materials
Item
1
2
3
C1
Reference
CAPACITANCE
RS
BULK
C1
C2
C2
RS
(for V
GND
REF
Application Information
GND
= 5 V, I
Value
0.25
0.22
Full-Bridge DMOS PWM Motor Drivers
100
OUT2
OUT1
VBB
OUT
= 2 A)
thermal pad of the device makes a good location for the star
ground point. The exposed pad can be connected to ground for
this purpose.
Layout
The PCB should have a thick ground plane. For optimum electri-
cal and thermal performance, the A4952/A4953 must be soldered
directly onto the board. On the underside of the A4952/A4953
package is an exposed pad, which provides a path for enhanced
thermal dissipation. The thermal pad must be soldered directly to
an exposed surface on the PCB in order to achieve optimal ther-
mal conduction. Thermal vias are used to transfer heat to other
layers of the PCB.
The load supply pin, VBB, should be decoupled with an electro-
lytic capacitor (typically 100 μF) in parallel with a lower valued
ceramic capacitor placed as close as practicable to the device.
Units
μF
μF
Ω
Thermal Vias
1
FLTn
RTRY
IN2
IN1
VREF
PCB
X5R minimum, 50 V or greater
Electrolytic, 50 V or greater
2512, 1 W, 1% or better,
carbon film chip resistor
A4952
A4952
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
PAD
Description
OUT2
OUT1
GND
VBB
LSS
Solder
Trace (2 oz.)
Signal (1 oz.)
Ground (1 oz.)
Thermal (2 oz.)
R
C1
S
C2
V
BB
7