A3955 Allegro MicroSystems, Inc., A3955 Datasheet - Page 6

• Manufacturer Part Number: A3955
• Description: Full-Bridge PWM Microstepping Motor Driver
• Manufacturer: Allegro MicroSystems, Inc.

A3955
Terminal
Note the A3955SB (DIP) and the A3955SLB
(SOIC) are electrically identical and share a
common terminal number assignment.
12-13
4-5
10
14
15
16
11
1
2
3
6
7
8
9
LOGIC SUPPLY (V
LOAD SUPPLY
GROUND
GROUND
PHASE
SENSE
Name
OUT
OUT
PFD
REF
RC
D
D
D
2
1
0
A
B
Description
(Percent Fast Decay) The analog input used to set the current-decay mode.
(V
D
The parallel combination of external resistor R
PWM current regulator. C
Return for the logic supply (V
measurements.
The PHASE input determines the direction of current in the load.
(DATA
(DATA
One-of-two output load connections.
Connection to the sink-transistor emitters. Sense resistor R
point and ground.
Return for the logic supply (V
measurements.
(DATA
One-of-two output load connections.
(V
Full-Bridge PWM Microstepping Motor Driver
0
REF
CC
BB
, D
) Supply voltage for the load.
) Supply voltage for the logic circuitry. Typically = 5 V.
) The voltage at this input (along with the value of R
1
, and D
2
1
0
) One-of-three (MSB) control bits for the internal digital-to-analog converter.
) One-of-three control bits for the internal digital-to-analog converter.
) One-of-three (LSB) control bits for the internal digital-to-analog converter.
2
) set the peak output current.
Terminal Functions
T
also sets the blanking time.
CC
CC
) and load supply (V
) and load supply (V
T
and capacitor C
BB
BB
); the reference for all voltage
); the reference for all voltage
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
S
and the states of DAC inputs
S
is connected between this
T
set the off time for the
6