432
Regulator ICs
6-channel switching regulator
controller
BA9736KV
The BA9736KV is a 6-channel controller that includes all of the circuits required to construct a switching regulator . The
circuits on the chip include a triangular-wave generator , a reference voltage circuit, an error amplifier, a PWM compara-
tor, a pseudo-totem-pole driver, and a variety of protection circuits.
Applications
VCR / cameras, digital still cameras, and other portable
equipment
Features
1) The totem-pole driver can directly drive power tran-
sistors, and the on current can be set to the rating cur-
rent using an external resistor.
2) Miss-operation prevention circuit for low-voltage input.
3) Output cutoff circuit (timer latch type) for overload
protection.
4) Channels 1 and 4 employ FETs, and have totem-pole
drivers that rectify synchronously with a chopper . The
duty offset of the chopper can be adjusted externally .
5) For channel control, by making STB low level, all
channels go off, and by making STB3 low level, chan-
nel 3 can be switched off independently.
6) Soft start is applied to all channels using an external
capacitor, and is synchronized with the rising edges
of STB and STB3.
7) VQFP64 package (0.5mm pitch).
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions (Ta = 25C)
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Regulator ICs BA9736KV
Block diagram
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Regulator ICs BA9736KV
Pin descriptions
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Regulator ICs BA9736KV
Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 7.2V, fOSC = 700kHz and output voltage off)
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Regulator ICs BA9736KV
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Regulator ICs BA9736KV
Measurement circuits
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Regulator ICs BA9736KV
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Regulator ICs BA9736KV
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Regulator ICs BA9736KV
Application example
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Regulator ICs BA9736KV
Operation notes
(1) Set the dead-time input voltage to 0.73V or more.
(2) Use short and wide wiring tracks for the power sup-
ply and ground to keep the mutual impedance as small
as possible, and use inductors and capacitors to keep
ripple to a minimum.
(3) Set RDUTY so that the drive stage and the MOS drive
stage for the synchronous rectifier channel are not on at
the same time.
(4) If you are not using the external trigger input (pin 13)
for overload output cutoff, pull it up to VCC (pin 28).
(5) Great care has been paid to the quality of this com-
ponent. However, if the absolute maximum ratings for
temperature and applied voltage are exceeded, the IC
may be destroyed. Since it is not possible to predict
whether it will be in short mode or open mode if the IC is
destroyed, if there is a chance that the maximum ratings
of the IC will be exceeded, use appropriate physical pro-
tective measures (fuses etc.).
External dimensions (Units: mm)