|
AP3720 Datasheet, PDF (1/13 Pages) BCD Semiconductor Manufacturing Limited – CURRENT MODE PWM CONTROLLER FOR BJT | |||
|
Preliminary Datasheet
CURRENT MODE PWM CONTROLLER FOR BJT
AP3720
General Description
The AP3720 is a low startup current, current mode
PWM controller with green-mode operation. The
PWM switching frequency at normal operation is 65k,
but when the output power drops below the
specifically level, the device enters the
frequency-drop mode and the typical operating
frequency is 20kHz (no audible noise). Additionally,
when the load drops to a very low level or zero, the
IC operates in so called âburst modeâ to minimize
switching loss.
The IC integrated a lot of functions such as the
Lead-Edge Blanking (LEB) of the current sensing,
internal slope compensation, line compensation, and
several protection features. The protection functions
include cycle-by-cycle current limit (OCP), VCC
over voltage protection (OVP), OTP and OLP.
The AP3720 is available in DIP-8 and SOIC-8
packages.
Features
⢠Low Startup Current ï¼ 2.5µA ï¼ and Low
Operating Current (1.2mA)
⢠Off-line Converter Applied in Sub 25W Range
⢠Skip Cycle Mode Achieves Low Standby Power
(<200mW)
⢠Cycle-by-Cycle Power Limited
⢠Frequency-drop Mode
⢠Soft Start with 2ms
⢠Programmable Drive Current for BJT
⢠Leading Edge Blanking
⢠Pre-shutdown Decreases Turn-off Losses
⢠Reliable Protection:
Accurate OCP with Line Compensation
Short Circuit Protection
Over Voltage Protection for VCC
Hysteretic Thermal Shutdown Protection
Applications
⢠STB
⢠Cable Modem
⢠ADSL Modem
⢠DVD Recorder
Jul. 2009 Rev. 1. 0
DIP-8
SOIC-8
Figure 1. Package Types of AP3720
BCD Semiconductor Manufacturing Limited
1
|
▷ |