mm1538 Mitsumi Electronics, Corp., mm1538 Datasheet - Page 20

• Manufacturer Part Number: mm1538
• Description: 4-ch Motor Driver For Portable Cd Players
• Manufacturer: Mitsumi Electronics, Corp.

MITSUMI
Circuit operation
1 H-bridge driver block
(1) Gain setting
(2) Mute function
(3) Vref drop mute
(4) Thermal shutdown
2 PWM power supply drive block
· The driver input resistance (ch 1,3 and 4) are 11kΩ typ. ,ch2 is 7.5kΩ typ. . Set the gain according to the
· The driver output stage power supply is HVcc(36PIN), and the bridge circuit power supply is VSYS2
· Of the four drivers,ch1 has a brake function,and the other channels have a mute function.
· When BRAKE1(23PIN)is set to high level, both ch1 outputs go low level, and the circuit enters brake mode.
· When MUTE2(21PIN)is set to high level, the ch2 output is muted.
· When MUTE34(19PIN)is set to high level, the ch3 and 4 outputs are muted.
· When the voltage applied to Vref(16PIN)is 1.0V or less typ. , the driver outputs are set to high impedance.
· When the chip temperature reaches 150°C typ. the output current is cut. The chip starts operating again at
· This detects the maximun output level from among the four channels, and supplies the load drive power
ch1
ch2
ch3
ch2
following formula.
(15PIN). Connect a bypass capacitor between these two power supplies(approximately 0.1µF).
about 120°C typ. .
supply(36PIN)for the PWM. The external components are a PNP transistor, coil, Schottky diode,and
capacitor.
2200pF
GV=20log
GV=20log
10pF
100kΩ
BATT
PWMFIL
11k
7.5k
44
55k
110k
+
+
R
47kΩ
R
(db)
(db)
PSW
37
R:Externally-connected input
SBD
33µH
4-ch Motor Driver for Portable CD Players MM1538
47µF
HV
36
CC
0.1µF