CN3305 |
PFM Step-up
Multi-cell Battery Charger IC |
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General Description: |
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CN3305 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 lithium-ion, LiFePO4 and
Lead Acid battery charge management with fewer external
components. CN3305 adopts constant current and quasi-constant
voltage(Quasi-CVTM) mode to charge battery.
On power up, CN3305 enters 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, 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 reaches 1.205V(Typ.) for the first time,
CN3305 enters quasi-CV mode, in which the charge current is
reduced. The charge process will not be terminated until FB
voltage reaches 1.205V for the second time. In termination mode,
the N-channel MOSFET is turned off. When FB voltage falls below
recharge threshold, the CN3305 enters charge mode again.
CN3305’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,
CN3305 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 status indication, etc.
CN3305 is available in 8-pin SOP package. |
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Applications: |
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Lithium-ion,LiFEPO4 and Lead-Acid Battery |
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Power Bank |
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Audio System |
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Standalone battery charger |
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Electric Appliance |
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Features: |
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Input Voltage Range:2.7V to 6.5V |
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Operating Current:280uA@VIN=5V |
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Inductor Current Detection |
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Switching Frequency up to 1MHz |
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Quasi-CV mode to Compensate for the Voltage Loss
on Battery Internal Resistance and Trace Resistance |
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Automatic Recharge |
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Output Power up to 35W |
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Protection for Battery Voltage Being Low than
Input and Short Battery |
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Good adaptability to Input Supply with Limited
Driving Capability |
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Chip Enable Input |
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Battery Overvoltage Protection |
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Status Indication |
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Operating Temperature Range:-40℃ to 85℃ |
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Available in SOP8 Package |
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Lead-free, rohs-Compliant
and Halogen Free |
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Application
Note: |
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