M54640P Datasheet, PDF (1/10 Pages) Mitsubishi Electric Semiconductor – STEPPER MOTOR DRIVER

M54640P
Stepper Motor Driver
Description
The M54640P is a semiconductor IC to drive a stepper motor by the bipolar method.
Features
• Bipolar and constant-current drive
• Wide current control rage (20 – 800mA)
• Wide supply voltage drive range (10 – 40V)
• Built in flywheel diodes
• Current level can be changed by steps or continuously.
• Built in a thermal shutdown circuit
REJ03F0042-0100Z
Rev.1.0
Sep.19.2003
Application
Printer, FDD, HDD, Fax
Function
The M54640P drives a stepper motor by the bipolar drive method to change the current direction of a single coil and
controls the current direction with PHASE input pin. In order to obtain higher efficiency, the constant current drive
system to control the coil current is introduced. The current value can be selected among four levels (0 to max.) by
selecting the combination of three internal comparators by logic input. It also can be continuously changed by
controlling the reference voltage. Conversion to voltage is conducted by the current value sensing resistor (Rs) and the
voltage is sensed with each comparator, and then each comparator output triggers monomulti and the current is cut for a
certain time (t_OFF) by utilizing the inductance of the coil.
Also, diodes needed for choppering and a thermal shutdown circuit as a countermeasure against overvoltage are built in
this circuit.
Pin Configuration
Output MB ← 1
One-shot-multi
time constant
T→ 2
Output power
supply
VMM
3
4
GND
5
Power supply VCC ₆
Output current
value setting
Output current
direction switching
I1 7
Ph → 8
16 → E Current sensor
15 → ^MA ^Output
14
VMM
Output power
supply
13
GND
12
11 ← ^VR
Comparator
reference input
10 ← ^{C Comparator input}
9
Io
Output current
setting
Outline 16P4
Rev.1.0, Sep.19.2003, page 1 of 9