AK7903 Datasheet, PDF (1/10 Pages) Asahi Kasei Microsystems – DCDC Step-down Converter for NiH2 Battery

[AK7903]
AK7903
DCDC Step-down Converter for NiH2 Battery
GENERAL DESCRIPTION
AK7903 is a DCDC step-down converter with fixed current control type for NiH2 battery. This device
detects external resistor current, and controls switching regulator output voltage with fixed current.
AK7903 can convert the battery voltage with a built-in general-purpose amplifier, so CPU can monitor
battery easily. AK7903 also built-in output voltage detection function (external resistors fail detection),
output short protection function, thermal protection circuit, so it can work safely with few radiant heat.
AK7903 is the most suitable charger device for portable system which uses NiH2 battery. The AK7903 is
available in QFN package (3.0mm x 3.0mm), utilizing less board space than competitive offerings.
FEATURE
Most Suitable Charger Device for NiH2 Battery Charging
- Switching DCDC Converter with Fixed Current Control Circuit
Power Supply Voltage: 4.1V～5.5V
Output Voltage: 0.2V～3.6V
Maximum Charger Current (pin control available):
- 0.4A @ ISET= “Low” (SENSE resistor= 0.353Ω)
- 0.3A @ ISET= “Low” (SENSE resistor= 0.470Ω)
- 80mA @ ISET= “High” (SENSE resistor= 0.470Ω)
Charger Current Accuracy: ±5%
Low Power Consumption: 2uA @ Shut-down
Switching Frequency: External Resistor Adjustable (< 10%)
High Efficiency: >80% @VIN=5V, Vout= 1.8V, Iout= 0.3A
General-purpose Amplifier Built-in
- Input Selectable (switch built-in)
Protection Function (Auto Recovery)
- Over Current Protection Circuit
- Thermal Protection Circuit: 120℃(Recovery at 100℃)
Ta: -30～70℃
Few External Parts needed: Power MOSFET built-in
Small Size Package: 16pins QFN (3mm×3mm, 0.5mm pitch)
Application: System which used 1 or 2 series NiH2 battery
MS1190-E-00
1
2010/6