LOW POWER PWM CONTROLLER FOR OFF-LINE BATTERY CHARGER
The AP3700/A is a green-mode pulse width modula-
tion (PWM) controller. It is specially designed for low
power applications such as off-line battery chargers,
where the needs for low standby power, space saving
and low cost are all required. In a battery charger rated
5V/1A, the maximum standby power is only 0.18W.
In normal operation, the AP3700/A switches on and
off at a fixed switching frequency of 60 kHz. With a
current limit capability of 460mA for AP3700 and
500mA for AP3700A, the AP3700/A can directly
drive the emitter of high voltage NPN transistor. When
output power falls below a given level, the IC enters
skip cycle mode to reduce power consumption.
The AP3700/A also features under-voltage lockout,
over-current and short circuit protections.
· Current Mode Control with Skip Cycle Capability
· Lower Operating Current: 0.45mA
· Fixed Switching Frequency: 60 kHz
· Frequency Dithering for Low EMI: ±2.5kHz
· Under-Voltage Lockout Protection
· Over-Current Protection
· Internal Short Circuit Protection
· Higher Output Voltage at OUT Terminal
· Low Total Cost Solution
· Battery Chargers
· Off-Line Power Supplies
The AP3700/A is available in TO-92 package.
Mar. 2008 Rev. 1. 4
Figure 1. Package Types of AP3700/A
BCD Semiconductor Manufacturing Limited