AP3125A/V/L/R
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AP3125A/V/L/R
A Product Line of
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NEW PROD UCT
GREEN MODE PWM CONTROLLER
Description
The AP3125A/V/L/R is a current mode PWM controller which is
optimized for high performance, low standby power and cost effective
offline flyback converters.
The PWM switching frequency at normal operation is internally fixed
(about 65kHz). In middle load, the IC will enter green mode to
improve system efficiency with the help of frequency foldback. A
minimum switching frequency (about 20kHz) is set to avoid the
audible noise. In no load or light load, the IC will enter the burst mode
to minimize standby power. Furthermore, the frequency dithering
function is built-in to reduce EMI emission.
Internal slope compensation allows more stable Peak-Current Mode
control over wide range of input voltage and load conditions. Internal
line compensation ensures constant output power limit over entire
universal line voltage range.
Comprehensive protection features are included, such as cycle-by-
cycle current limit (OCP), VCC Over Voltage Protection (VOVP),
internal OTP, Over Load Protection (OLP) and pins’ fault protection.
The versatile latch functions can be implemented using a minimal
number of external components.
Features
Very Low Start-up Current
Current Mode Control
Non-audible-noise Green-mode Control
Internal Slope Compensation
Soft Start During Startup Process
Frequency Fold Back for High Average Efficiency
Secondary Winding Short Protection with FOCP
Soft Switching for Reducing EMI
VCC Maintain Mode
Useful Pin Fault Protection:
SENSE Pin Floating
CTRL Pin Short to Ground
FB/Opto-coupler Open/Short
Comprehensive System Protection Feature:
VCC Over Voltage Protection (VOVP)
Over Load Protection (OLP)
Optional Latch Mode for VOVP, OLP and CTRL Pin Protection
Mini Size Package of SOT26
Pin to Pin Compatible with AP3105NA/NV/NL/NR
Totally Lead-free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Pin Assignments
(Top View)
SOT26
Applications
Switching AC-DC Adapter/Charger
ATX/BTX Auxiliary Power
Set-top Box (STB) Power Supply
Open Frame Switching Power Supply
Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
1
2
3 4
5
Pin 1 Mark
6
GND
FB
CTRL
GATE
VCC
SENSE
AP3125A/V/L/R
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AP3125A/V/L/R
A Product Line of
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NEW PROD UCT
Typical Applications Circuit
~
~
+
-
VCC
GND
GATE
FB
SENSE
CTRL
~
AZ431
AP3125A/V/L/R
L2
T1
R13 C7
C6
C8
R14
R15
R16 R17
R18
C9
C10
R12R11
R10
R9
C5R6
R19
C4
R5
R4
C2
C1
VR1
U1
NTC
R2 R3
F1
R7
C3
C11
NTC
R8
Pin Descriptions
Pin Number
Pin Name
Function
1
GND
Signal ground. Current return for driver and control circuits
2
FB
Feedback. Directly connected to the opto-coupler
3
CTRL
Latch trigger if this pin voltage drops below a threshold or over another threshold, leave CTRL pin
open if this function is not needed. Connecting a NTC thermistor to GND can achieve OTP
protection
4
SENSE
Current Sense
5
VCC
Supply voltage of driver and control circuits
6
GATE
Gate driver output
AP3125A/V/L/R
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© Diodes Incorporated
AP3125A/V/L/R
A Product Line of
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NEW PROD UCT
Functional Block Diagram
GND
GATE
250ns LEB
Driver 13V
OSC with
Frequency
Jitter
0.95V
VCC_OVP
OLP
VCC
32V 28V
VCC_OVP
CTRL
UVLO
16V
7.6V
1V
Auto
Recovery
Protection
AP3125A/V/L/R
100mA
FB
R
2R
PWM
0.3V
1.3V
Latch-off
Protection
70mS
Debounce
OLP
FOCP
3V
4.5V0.6V
10k
CTRL_H
CTRL_L
OCP
SS
SS
VDD
Line
Compensation
Soft
Start
1.80V
FOCP
QD
CLK RB
DFF
OTP
VCC
VDD
OTP
CTRL_H
CTRL_L
VDD
Internal
Bias
150 C
o/125oC
SENSE
1
2
5
4
3
6
AP3125A/V/L/R
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AP3125A/V/L/R
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NEW PROD UCT
Absolute Maximum Ratings (Note 4)
Symbol
Parameter
Rating
Unit
VCC
Power Supply Voltage
30
V
IO
Gate Output Current
350
mA
VFB, VSENSE, VCTRL
Input Voltage to FB, SENSE, CTRL
-0.3 to 7
V
θJA
Thermal Resistance (Junction to Ambient)
250
°C/W
PD
Power Dissipation at TA < +25°C
500
mW
TJ
Operating Junction Temperature
-40 to +150
°C
TSTG
Storage Temperature Range
+150
°C
–
ESD (Human Body Model)
3000
V
–
ESD (Machine Model)
300
V
Note 4: 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.
Recommended Operating Conditions
Symbol
Parameter
Min
Max
Unit
VCC
Supply Voltage
10
25
V
AP3125A/V/L/R
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Electrical Characteristics (@TA = +25°C, VCC = 16V, unless otherwise specified.)
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
Supply Voltage (VCC Pin)
ISTARTUP
Startup Current
–
–
1
10
μA
ICC
Operating Supply Current
VFB=0V, CL=1nF
0.5
0.7
1
mA
VFB=3V, CL=0nF
0.6
1.2
2.0
–
UVLO (on)
–
14.5
15.8
16.5
V
–
VCC Maintain
–
8.6
9.1
9.6
V
–
UVLO (off)
–
7.1
7.6
8.1
V
–
VCC OVP
–
27
28.5
30
V
–
VCC Clamp
ICC=5mA
31
34
–
V
PWM Section/Oscillator Section
–
Maximum Duty Cycle
–
70
75
80
%
–
Oscillation Frequency
–
60
65
70
kHz
–
Green Mode Frequency
–
20
–
30
kHz
–
Frequency Temperature
Stability
-20°C to 125°C (Note 5)
–
–
5
%
–
Frequency Voltage Stability
VCC=12V to 30V
–
–
3
%
–
Frequency Dithering
–
±4
±6
±8
%
Current Sense Section (SENSE Pin)
VCS
Maximum SENSE Voltage
VFB=4.5V
0.9
0.95
1
V
–
FOCP Voltage
–
1.5
1.7
1.9
V
–
LEB Time of SENSE
–
150
250
350
ns
–
Delay to Output (Note 5)
–
–
100
–
ns
–
Soft-start Time
–
3
5
8
ms
Feedback Input Section (FB Pin)
–
The Ratio of Input Voltage to
Current Sense Voltage
–
2.5
3
3.5
V/V
–
Input Impedance
–
12
15
18
kΩ
–
Source Current
VFB=0V
-0.2
-0.27
-0.34
mA
–
Green Mode Threshold
–
–
2.1
–
V
–
Input Voltage for Zero Duty
–
1.3
1.55
1.8
V
Output Section (GATE Pin)
–
Output Low Level
IO=20mA, VCC=12V
–
–
1
V
–
Output High Level
IO=20mA, VCC=12V
8
–
–
V
–
Output Clamping Voltage
–
11
13
15
V
–
Rising Time (Note 5)
CL=1nF, VCC=13V
–
150
250
ns
–
Falling Time (Note 5)
CL=1nF, VCC=13V
–
50
100
ns
AP3125A/V/L/R
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AP3125A/V/L/R
A Product Line of
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NEW PROD UCT
Electrical Characteristics (Cont.) (@TA = +25°C, VCC = 16V, unless otherwise specified.)
Protection Section (CTRL Pin)
–
Source Current
–
90
100
110
μA
–
Internal Reference Voltage
–
–
1.9
–
V
–
Low Threshold Trigger for
Latch
–
0.94
1
1.06
V
–
High Threshold Trigger for
Latch
–
2.85
3
3.15
V
–
Pull-up Current (Note 6)
–
–
–
2
mA
Delay Time Section
–
Delay of Short Circuit
Protection
–
–
70
–
ms
–
Delay of Hiccup Protection
VCC OVP
–
5
–
Cycles
Internal OTP Section
–
OTP Enter
–
–
150
–
°C
–
OTP Exit
–
–
125
–
°C
Note 5: Guaranteed by design.
Note 6: The sourcing current of CTRL pin must be limited below 5mA. Otherwise it may cause permanent damage to the device.
AP3125A/V/L/R
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AP3125A/V/L/R
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NEW PROD UCT
Performance Characteristics
Startup Voltage vs. Ambient Temperature Shutdown Voltage vs. Ambient Temperature
Startup Current vs. Ambient Temperature Operating Current vs. Ambient Temperature
CTRL Utilization for Latch
CTRL
VCC
NTC
CTRL
VCC
NTC
VCC
CTRL
NTC
OVP and OTP OVP OTP
-40 -20 0 20 40 60 80 100 120 140
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Startup Current (mA)
Ambient Temperature (oC)
-40 -20 0 20 40 60 80 100 120 140
13
14
15
16
17
18
Startup Voltage (V)
Ambient Temperature (oC)
-40 -20 0 20 40 60 80 100 120 140
6.5
7.0
7.5
8.0
8.5
9.0
Shutdown Voltage (V)
Ambient Temperature (oC)
-40 -20 0 20 40 60 80 100 120 140
0.5
0.6
0.7
0.8
0.9
VFB=3V, CL=0
Operating Current (mA)
Ambient Tempture (oC)
AP3125A/V/L/R
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AP3125A/V/L/R
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Operation Description
The AP3125A/V/L/R is specifically designed for off-line AC-DC
power supply used in LCD monitor, notebook adapter and battery
charger applications. It offers a cost effective solution with a
versatile protection function.
Start-up Current and UVLO
The start-up current of AP3125A/V/L/R is optimized to realize ultra
low current (1mA typical) so that VCC capacitor can be charged
more quickly. The direct benefit of low start-up current is the
availability of using large start-up resistor, which minimizes the
resistor power loss for high voltage AC input.
An UVLO comparator is included in AP3125A/V/L/R to detect the
voltage on VCC pin. It ensures that AP3125A/V/L/R can draw
adequate energy from hold-up capacitor during power-on. The turn-
on threshold is 16V and the turn-off threshold is 7.6V.
Current Sense Comparator and PWM Latch
The AP3125A/V/L/R operates as a current mode controller, the
output switch conduction is initiated by every oscillator cycle and is
terminated when the peak inductor current reaches the threshold
level established by the FB pin. The inductor current signal is
converted to a voltage signal by inserting a reference sense resistor
RS. The inductor current under normal operating conditions is
controlled by the voltage at FB pin. The relation between peak
inductor current (IPK) and VFB is:
SFBPK RVI 3/)8.0(
Moreover, FOCP with 1.8V threshold is only about 100ns delay,
which can avoid some catastrophic damages such as secondary
rectifier short test. Few drive cycles can alleviate the destruction
range and get better protection.
Leading-edge Blanking
A narrow spike on the leading edge of the current waveform can
usually be observed when the power MOSFET is turned on. A
250ns leading-edge blank is built-in to prevent the false-triggering
caused by the turn-on spike. During this period, the current limit
comparator is disabled and the gate driver can not be switched off.
At the time of turning off the MOSFET, a negative undershoot
(maybe larger than -0.3V) can occur on the SENSE pin. So it is
strongly recommended to add a small RC filter or at least connect a
resistor “R” on this pin to protect the IC (Shown as Figure 1).
FB
SENSE
GATE
GND
CTRL 6
1
3
4
AP3125A/
V/L/R
VCC
5
2
Large undershoot (more than
-0.3V) may damage the SENSE pin
R
C
Necessary
Figure 1
Built-in Slope Compensation
It is well known that a continuous current mode SMPS may become
unstable when the duty cycle exceeds 50%. The built-in slope
compensation can improve the stability, so there is no need for
design engineer to spend much time on that.
FB Pin and Short Circuit Protection
This pin is normally connected to the opto-coupler and always
paralleled with a capacitor for loop compensation. When the voltage
at this pin is greater than 4.5V and lasts for about 70ms, the IC will
enter the protection mode. For AP3125A/V/L/R, the system will
enter hiccup mode to wait the VCC decreasing to low UVLO level,
then the IC will try to restart until the failure removed. And when this
voltage is less than 1.55V, the IC will stop the drive pulse
immediately. Therefore, this feature can be used for short circuit
protection, which makes the system immune from damage.
Normally, output short makes the VFB value to the maximum
because the opto-coupler is cut off.
VCC Maintain Mode
During light load or step load, VFB will drop and be lower than 1.55V,
thus the PWM drive signal will be stopped, and there is no more
new energy transferred due to no switching. Therefore, the IC
supply voltage may reduce to the shutdown threshold voltage and
system may enter the unexpected restart mode. To avoid this, the
AP3125A/V/L/R hold a so-called VCC maintain mode which can
supply energy to VCC.
When VCC decreases to a setting threshold, the VCC maintain
comparator will output some drive signal to make the system switch
and provide a proper energy to VCC pin. The VCC maintain function
will cooperate with the PWM and burst mode loop which can make
the output voltage variation be within the regulation. This mode is
very useful for reducing startup resistor loss and achieving a better
standby performance with a low value VCC capacitor. The VCC is
not easy to touch the shutdown threshold during the startup process
and step load. This will also simplify the system design. The
minimum VCC voltage is suggested to be designed a little higher
than VCC maintain threshold thus can achieve the best balance
between the standby and step load performance。
System Protection and Pin Fault Protection
The AP3125A/V/L/R provides versatile system and pin fault
protections. The OCP comparator realizes the cycle-by-cycle
current limiting (OCP). In universal input line voltage, the IC realizes
the constant over load protection (OLP). VCC over voltage
protection can be applied as the primary OVP or opto-coupler
broken protection. The AP3125A/V/L/R also has pin fault
connection protection including floating and short connection. The
floating pin protection includes the SENSE, FB, etc. The short pin
protection includes the CTRL pin short protection. When these pins
are floated or CTRL pin is shorted to ground, PWM switching will be
disabled, thus protecting the power system.
Latch Protection Function
For some applications, the system requires the latch protection
function. The CTRL pin has two kinds of modes to trigger the latch
protection: high level trigger and low level trigger. The low threshold
is 1V and high threshold voltage is 3V. Some version will have only
one mode. Once the latch protection is triggered, the IC will disable
the output signal, and the bulk capacitor provides the energy to IC
through the startup resistor to ensure the IC disable the output
(latch mode). This mode will be not released until the AC input is
shut off. So, the de-latch time is mainly depending on the HV
startup bulk capacitor value. Therefore, if the system wants a short
de-latch time, it is better for the startup resistor take power from the
point before the rectifier bridge as illustrated in Figure 2.
AP3125A/V/L/R
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AP3125A/V/L/R
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NEW PROD UCT
Operation Description (Cont.)
Internal OTP Protection Function
The AP3125A/V/L/R integrates an internal temperature sensor. It
has a trigger window of +150°C enter and +125°C exit. The internal
OTP protection mode is auto-recovery mode.
VCC
GND
FB
CTRL
AP3125A/V/L/R
SENSE
AC Mains
(90V to 265V) CBUS
GATE
1
2
3
4
56
Figure 2
AP3125A/V/L/R
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NEW PROD UCT
Ordering Information
AP3125XX XX XX - G1
Packing
Package
TR : Tape & Reel
K : SOT26 G1 : Green
Product Name RoHS/Green
Product Version*
A : AP3125A
V : AP3125V
L : AP3125L
R : AP3125R
Diodes IC’s Pb-free products with "G1" suffix in the part number, are RoHS compliant and green.
Package
Part Number
Marking ID
Packing
SOT26
AP3125AKTR-G1
GLS
3000/Tape & Reel
AP3125VKTR-G1
GLU
3000/Tape & Reel
AP3125LKTR-G1
GNB
3000/Tape & Reel
AP3125RKTR-G1
GNC
3000/Tape & Reel
*Product Version Classification (with Different Protection Functions)
Product Version
Frequency
VOVP
OLP & SOCP
CTRL (Low)
CTRL (High)
AP3125A
65kHz
Auto-Recoverable
Auto-Recoverable
Latch
Auto-Recoverable
AP3125V
65kHz
Latch
Auto-Recoverable
Latch
Latch
AP3125L
65kHz
Latch
Latch
Latch
Latch
AP3125R
65kHz
Auto-Recoverable
Auto-Recoverable
Auto-Recoverable
Latch
Marking Information
(Top View)
: Logo
XXX: Marking ID (See Ordering Information)
AP3125A/V/L/R
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Package Outline Dimensions (All dimensions in mm(inch).)
(1) Package Type: SOT26
2.820(0.111)
3.100(0.122)
2.650(0.104)
3.000(0.118)
1.500(0.059)
1.700(0.067)
0.950(0.037)TYP
1.800(0.071)
2.000(0.079)
0.300(0.012)
0.500(0.020)
0.700(0.028)REF
0.100(0.004)
0.200(0.008)
0°
8°
0.200(0.008)
0.300(0.012)
0.600(0.024)
0.000(0.000)
0.150(0.006)
0.900(0.035)
1.300(0.051) 1.450(0.057)
MAX
1 2 3
4
5
6
Pin 1 Mark
AP3125A/V/L/R
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Suggested Pad Layout
(1) Package Type: SOT26
E E
GZ
Y
X
Dimensions
Z
(mm)/(inch)
G
(mm)/(inch)
X
(mm)/(inch)
Y
(mm)/(inch)
E
(mm)/(inch)
Value
3.600/0.142
1.600/0.063
0.700/0.028
1.000/0.039
0.950/0.037
AP3125A/V/L/R
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NEW PROD UCT
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INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
(AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
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final and determinative format released by Diodes Incorporated.
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written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the
labeling can be reasonably expected to result in significant injury to the user.
B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the
failure of the life support device or to affect its safety or effectiveness.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and
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