Diodes AP1680 User Manual
Preliminary Datasheet
LOW-POWER OFF-LINE PRIMARY SIDE REGULATION CONTROLLER AP1680
General Description
The AP1680 is a high performance AC/DC power supply controller for LED drivers, battery charger and
adapter applications. The device uses Pulse Frequency
Modulation (PFM) method to build discontinuous conduction mode (DCM) flyback power supplies.
The AP1680 provides accurate constant voltage, constant current (CV/CC) regulation while removing the
opto-coupler and secondary control circuitry. It also
eliminates the need of loop compensation circuitry
while maintaining stability. The AP1680 achieves
excellent regulation and high average efficiency, yet
meets the requirement for no-load consumption less
than 30mW.
The AP1680 is available in SOT-23-6 package.
Features
· Primary Side Control for Rectangular Constant
Current and Constant Voltage Output
· Sub-microampere Start-up Current
· 30mW No-load Input Power Feasible
· Tight CC Regulation Performance
· Eliminates Opto-coupler and Secondary CV/CC
Control Circuitry
· Eliminates Control Loop Compensation Circuitry
· Flyback Topology in DCM Operation
· Random Frequency Modulation to Reduce
System EMI
· Built-in Soft Start
· Open Feedback Protection
· Short Circuit Protection
· SOT-23-6 Package
Applications
· LED Drivers
· Adapters/Chargers for Cell/Cordless Phones,
PDAs, MP3 and Other Portable Apparatus
· Standby and Auxiliary Power Supplies
SOT-23-6
Figure 1. Package Type of AP1680
BCD Semiconductor Manufacturing LimitedApr. 2011 Rev. 1. 0
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Preliminary Datasheet
LOW-POWER OFF-LINE PRIMARY SIDE REGULATION CONTROLLER AP1680
Pin Configuration
K6 Package
(SOT-23-6)
Pin 1 Dot by Marking
OUT
GND
VCC
Figure 2. Pin Configuration of AP1680 (Top View)
1
2
34
FB
6
GND
5
CS
Pin Description
Pin Number Pin Name Function
1 OUT This pin drives the base of external power NPN switch
2, 5 GND
3 VCC Supply voltage
4 CS The primary current sense
6 FB The voltage feedback from the auxiliary winding
Ground
BCD Semiconductor Manufacturing LimitedApr. 2011 Rev. 1. 0
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Preliminary Datasheet
LOW-POWER OFF-LINE PRIMARY SIDE REGULATION CONTROLLER AP1680
Functional Block Diagram
VCC
3
0.1V
6
FB
CS
4
COMP
pfm
EA
4.0V
Constant Voltage Control
Peak Current Control & LEB
Tonsec
Detector
OCk P
Tons
RQ
S
Regulator
&
Bias
CV_ctrl
pfm
UVLO
Driver
1
OUT
Tons
Constant C urrent Control
Figure 3. Functional Block Diagram of AP1680
RQ
S
BCD Semiconductor Manufacturing LimitedApr. 2011 Rev. 1. 0
CC_ctrl
2, 5
GND
3
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