STA6940M Datasheet, PDF (1/19 Pages) Allegro MicroSystems – Brushed DC Motor Driver IC With PWM Control

STA6940M
Brushed DC Motor Driver IC With PWM Control
Features and Benefits
▪ Power supply voltage, V_BB , 44 V maximum, 10 to 40 V
normal operating range
▪ Logic supply voltage, V_DD , 3 to 5.5 V compatible
▪ Output current, I_O ,4 A average, 8 A maximum
▪ Output elements are all N-channel MOSFETs to reduce
losses
▪ Internal charge pump
▪ Forward, reverse, free, and brake control modes available
▪ Constant-current control:
▫ Off-time 35 μs, fixed (Slow Decay mode)
▪ Internal Overcurrent Protection (OCP) circuitry
▫ Off-time 142 μs fixed (Fast Decay mode)
▪ Internal Thermal Shutdown (TSD) circuitry
▪ ZIP type 18-pin fully-molded package (STA package)
Package: 18-pin ZIP (STA)
Description
Combining low-power CMOS-compatible logic with high-
current, high-voltage power MOSFET outputs, the STA6940M
provides complete control and drive for brush DC motors.
It provides internal fixed off time, pulse-width modulation
(PWM) control of the output current, rated for 4 A normal
operating level.
The CMOS logic section provides four modes of operation:
forward and reverse normal drive rotation, outputs-off free
spin (coast), and electronic braking.
The innovative multi-chip internal structure separates the main
logic IC (MIC) from the four N-channel power MOSFETs. This
results in lower thermal resistance and greater efficiency.
PWM control allows constant-current control of output while
reducing heat generation and power losses by providing fixed
off-time dual decay modes. The internal charge pump ensures
full power availability for switching.
Not to scale
28106.01
Functional Block Diagram
VDD
7
CP CP1 CP2 VBB VBB
14 13 12
18 1
MIC
5
IN1
6
IN2
11
Diag
PWM_REF ⁸
OCP_REF ⁹
Charge Pump
Reg
UVLO
Logic
Pre-Driver
Comp
PWM and
Comp OCP Control
OSC
Reg
2
OA
3
OA
16
OB
17
OB
10
GND
15
4
Sense2 Sense1