ROHM BH6511

Optical disc ICs
4-channel PWM driver for CD and MD
players
BH6511FS
The BH6511FS is an IC designed for CD and MD player motors and actuators, and has an internal 4-channel PWM driver, and a charge pump circuit that supplies the gate drive for the output stage power MOSFET. The power MOSFET in
the output stage assures low power consumption for applications.
FApplications
CD and MD players
FFeatures
1) Internal 4-channel power MOS H-bridge.
2) Adaptable for PWM input.
3) Internal charge pump circuit to raise VG voltage.
4) Low ON resistance.
5) Low power consumption.
6) 32-pin SSOP-A compact package.
FAbsolute maximum ratings (Ta = 25_C)
FRecommended operating conditions
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Optical disc ICs
Block diagram
Pin descriptions
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BH6511FS
Optical disc ICs
BH6511FS
Pin equivalent circuit diagrams
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Optical disc ICs
BH6511FS
FElectrical characteristics (unless otherwise noted, Ta = 25_C, VM = 5V, VDD = 3V, VG = internal charge pump output,
fIN = 176kHz, RL = 8Ω –47µH)
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Optical disc ICs
BH6511FS
Measurement circuit
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Optical disc ICs
Circuit operation
(1) PWM driver
The output stage is an H-bridge driver with four N-type
FET circuits. Output PWM duty is changed according to
input PWM duty. This pulse drives the load (direct PWM).
Driver truth table
(2) Charge pump
A dedicated charge pump that supplies the drive voltage
to the output stage H-bridge power MOSFET.
(3) Because the charge pump circuit doubles the voltage using pin 9 voltage as its reference, VG is not output
unless VM is impressed on pin 9. Also, be sure to set the
VM voltage to keep the charge pump voltage under the
absolute maximum rating.
(4) When supplying VG directly from an external
source, rather than using the internal charge pump circuit, disconnect the capacitor between pins 31 and 32.
(5) A charge pump capacitor between 0.01 and 0.1µF
is recommended. Using one with a greater capacity will
not significantly improve performance.
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BH6511FS
Optical disc ICs
BH6511FS
Application example
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Optical disc ICs
Electrical characteristic curves
Extermal dimensions (Units: mm)
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BH6511FS