
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

Preliminary Datasheet
LOW-POWER OFF-LINE PRIMARY SIDE REGULATION CONTROLLER AP1680
Ordering Information
AP1680 -
Circuit Type
G1: Green
Package
K6: SOT-23-6
Package Temperature Range Part Number Marking ID Packing Type
SOT-23-6
BCD Semiconductor's products, as designated with "G1" suffix in the part number, are RoHS compliant and Green.
-40 to 105
o
C
AP1680K6TR-G1 GBF Tape & Reel
TR: Tape and Reel
Absolute Maximum Ratings (Note 1)
Parameter Value Unit
Supply Voltage VCC -0.3 to 36 V
Voltage at CS, OUT to GND -0.3 to 7 V
FB Input -40 to 10 V
Output Current at OUT Internally limited A
o
C/W
o
C
o
C
o
C
Operating Junction Temperature 150
Storage Temperature -65 to 150
Lead Temperature (Soldering, 10s) 300
Thermal Resistance Junction-to-Ambient 250
ESD (Machine Model) 200 V
ESD (Human Body Model) 2000 V
Note 1: Stresses greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the device.
These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated
under "Recommended Operating Conditions" is not implied. Exposure to "Absolute Maximum Ratings" for extended periods
may affect device reliability.
BCD Semiconductor Manufacturing LimitedApr. 2011 Rev. 1. 0
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Preliminary Datasheet
LOW-POWER OFF-LINE PRIMARY SIDE REGULATION CONTROLLER AP1680
Electrical Characteristics
(VCC=15V, TA=25oC, unless otherwise specified.)
Parameter Symbol Conditions Min Typ Max Unit
UVLO SECTION
Start-up Threshold
V
TH (ST)
16 18.5 21 V
Minimal Operating Voltage V
(min) 7.2 9 10.2 V
OPR
STANDBY CURRENT SECTION
Start-up Current
Operating Current I
I
ST
CC(OPR)
VCC=V
Before start-up
Static 200 320 µA
TH (ST)
-0.5V,
0.6 µA
DRIVE OUTPUT SECTION
OUT Maximum Current
Sink
I
OUT
50
mA
Source 24 30 36
CURRENT SENSE SECTION
Current Sense Threshold
Equivalent Current Sense Voltage Accuracy
V
CS
eqVcs,
Note 2 3 %
455 510 545 mV
eqVcs,
Pre-Current Sense
V
CS(PRE)
365 410 455 mV
Leading Edge Blanking 750 ns
FEEDBACK INPUT SECTION
FB
VFB=4V
2.0 2.5 3.1 µA
3.59 3.83 4.07 V
Feedback Pin Input Leakage Current
Feedback Threshold
I
FB
V
Note 2: The output current is given by I
Np
eqVcs,
= .
OUT
Rcs
x
x
Ns
5
BCD Semiconductor Manufacturing LimitedApr. 2011 Rev. 1. 0

Preliminary Datasheet
LOW-POWER OFF-LINE PRIMARY SIDE REGULATION CONTROLLER AP1680
Typical Performance Characteristics
21
20
19
18
Start-up Voltage (V)
17
16
-40 -20 0 20 40 60 80 100 120
Ambient Temperature (oC)
Figure 4. Start-up Voltage vs. Ambient Temperature
10.5
10.0
9.5
9.0
8.5
Minimal Operating Voltage (V)
8.0
7.5
-40 -20 0 20 40 60 80 100 120
Ambient Temperature (oC)
Figure 5. Mininal Operating Voltage vs.
Ambient Temperature
300
280
260
240
220
200
180
160
Operating Current (µA)
140
120
100
-40-200 20406080100120
Ambient Temperature (oC)
Figure 6. Operating Current vs. Ambient Temperature
6
5
4
3
(µA)
FB
I
2
1
0
-40 -20 0 20 40 60 80 100 120
Ambient Temperature (oC)
Figure 7. IFB vs. Ambient Temperature
BCD Semiconductor Manufacturing LimitedApr. 2011 Rev. 1. 0
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Preliminary Datasheet
LOW-POWER OFF-LINE PRIMARY SIDE REGULATION CONTROLLER AP1680
Typical Application
+
C1
R1
R2
R3
VCC
+
C2
OUT
AP1680
FBCS
R4
Figure 8. 16.5V/350mA Output for LED Driver
GND
D1
Q1
Rs
R5 C3
D3
NV
R6
R7
Ns
D2
C4
VO+
+
V
-
O
T1
NV
P
FB
BCD Semiconductor Manufacturing LimitedApr. 2011 Rev. 1. 0
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BCD Semiconductor Manufacturing Limited
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particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use
particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use
of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or
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