| CN3387 |
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PFM Step-up Multi-cell NIMH
Battery Charger IC |
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| General Description： |
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CN3387 is a PFM mode step-up battery charge
management IC with operating voltage range between 2.7V to 6.5V.
It is specially designed for multi-cell NIMH battery charge
management with fewer external components. CN3387 adopts
constant current and maintenance mode to charge battery.
On power up, CN3387 enters constant current charging mode, the
external N-channel MOSFET is turned on, inductor current rises.
When inductor current reaches upper threshold, the N-channel
MOSFET is turned off, then inductor is discharged, the energy
stored in inductor is transferred to battery. When the inductor
current is discharged to its lower threshold, the N-channel
MOSFET is turned on again. When FB pin voltage rises to 1.124V (Typ.)
, CN3387 enters maintenance mode, in which the input current is
reduced, in the meantime a timer is started. The charge process
will not be terminated until the time out occurs. In termination
mode, the N-channel MOSFET is turned off. When FB pin voltage
falls below recharge threshold, the CN3387 enters charge mode
again. CN3387’s switching frequency can be up to 1MHz, which
makes a small-profile inductor usable.
If battery voltage is lower than input voltage by a diode drop,
CN3387 will increase the off time to 5us to reduce the charge
current as a protection for battery with the joint action of
external N-channel and P-channel MOSFET.
The other features include chip enable input, status indication,
etc.
CN3387 is available in 10-pin SSOP package. |
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| Applications： |
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Standalone NIMH Battery
Charger |
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Electric Tools |
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Toys |
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Car Models, Aero-modeling |
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| Features： |
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Input Voltage Range：2.7V
to 6.5V |
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Maintenance Charge Mode
to Guarantee Fully-charged Battery |
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Charging terminated by
Timer |
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Charge Current up to 1A |
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Automatic Recharge |
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Output Power up to 35W |
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Indicators for Charge and termination status |
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Protection for Low
Battery Voltage and Short Battery |
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Chip Enable Input |
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Battery Overvoltage
Protection |
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Available in SSOP10 Package |
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Pb-free, rohs compliant and Halogen free |
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Application
Note： |
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Quick
Start of CN3387 Demo Board |
