Product parameters

Funtion：PFM Step-up Multi-cell NIMH Battery Charger IC

Opration Mode：Switch

Battery：Standalone NIMH Battery

Battery No.：4-12

Vout Range：0V-18V

Vin Range：2.7V - 6.5V

Operating Current：300uA

Solar Panel charge：Yes

Chip Temperature Regulation：No

Package：SSOP10

Chip Enable：Yes

On-chip Power MOSFET：No

General Description：

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 or FB pin voltage reaches 1.205V. 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.

Applications:

l  Standalone NIMH Battery Charger

l  Electric Tools

l  Toys

l  Car Models, Aero-modeling

Features：

l  Input Voltage Range：2.7V to 6.5V

l  Operating Current：300uA@VIN=5V

l  Inductor Current Detection

l  Can be Powered by Solar-Panel

l  Switching Frequency up to 1MHz

l  Maintenance Charge Mode to Guarantee Fully-charged Battery

l  Charging terminated by Timer

l  Automatic Recharge

l  Output Power up to 35W

l  Protection for Low Battery Voltage and Short Battery

l  Automatic Adaptability to Input Supply with Limited Driving Capability

l  Chip Enable Input

l  Battery Overvoltage Protection

l  Status Indication

l  Operating Temperature ：－40℃ to 85℃

l  Available in SSOP10 Package

l  Lead-free, rohs-Compliant and Halogen Free