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IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Cont®
roller – Easy Opto Failsafe Protection
IN-PLUG series: IPS15H
Enhanced Off-line Switcher With Hiccup,
Low Cost, High Efficiency, Low Stand-By Power.
Fail-Safe Protection from Optocoupler Failure
When Combined with Low Power Zener.
– REVISION 10 INTRODUCTION
DESCRIPTION
The IN-PLUG® IPS15H is an enhanced off-line
switcher version of the IPS15 that includes the same
basic features plus offers a special overload
protection mode called “hiccup” to control the
maximum output power from the line side and
eliminate the current sensing circuitry on the load
side.
The original functions of the IPS15 have been
retained. They include soft start, line over-voltage
protection, shunt-regulator, precision oscillator, PWM
with its associated comparator and loop compensation
components as well as all the necessary biasing and
protection circuitry (thermal shutdown, under-voltage,
over-voltage and over-current).
The IPS15H “hiccup” circuitry involves a counter and
some other digital blocks. This feature has been added
to avoid delivering a high current to the load in an
overload condition, which may result in damages to
the SMPS, the load or both.
The overload condition is sensed from the line-side by
monitoring the MOSFET current. The MOSFET must
be allowed to operate at maximum current for the
SMPS to properly start and respond to transient
conditions. If the operation at maximum current is too
long, then it is in an overload condition and the circuit
enters "Hiccup Mode". The peak current in the load is
still high in order to be able to return to normal mode,
but the duty cycle is so low that the average current
drops below 100mA therefore allowing the SMPS to
remain overloaded indefinitely without any reliability
or safety concerns.
The IPS15H not only protects against overload
conditions but also avoid the losses involved in the
sensing circuitry which increases the overall SMPS
efficiency by up to 10%. This is significant!
FEATURES
• “Hiccup” version of the IPS15 with overload
protection.
• Max output power controlled from line-side to
avoid load-side current sensing circuitry and
associated 10% losses.
• Fail-safe protection from optocoupler failure
when combined with low-cost low-power zener.
• Lower quiescent current (max. 50% of the IPS15)
• Can drive a large variety of power MOSFETs
• Simple, less critical, lower cost transformer.
• Wide range PWM for stable operation at any load
and line voltage.
• Operates with optocoupler or bias winding for
constant voltage applications: zeners, adjustable
shunt regulator like TL431.
• EMI reduction in critical applications thanks to:
ƒ Adjustable operating frequency.
ƒ Separate MOSFET N & P drives
• Power shut-down for stand-by modes.
• Cycle to cycle over-current protection
• Under-voltage lock-out
• Line over-voltage protection.
• External component savings: MOV, X-cap, Y-cap
(Application permitting)
APPLICATIONS
• Standby power supplies for TV, VCR and IR
remotely-controlled appliances.
• Cordless and feature phones.
• Cellular phone chargers.
• Power tools fast chargers with trickle and on/off.
• Laptops and personal digital assistants.
• Utility meters.
• Replacements for bulky plug-in transformers.
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
1 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
PIN CONFIGURATION:
ORDERING INFORMATION
DIP-8 / SOIC-8
Part No.
1
PDRIVE
8
ISENSE
RBIAS
4
5
Package
Temperature Range
Pb-Free
GND
IPS15HC-D
-G-LF
8-Pin PDIP
0°C to +70°C
Commercial
OPTO
IPS15HI-D
-G-LF
8-Pin PDIP
-40°C to +85°C
Industrial
OVERV
IPS15HC-SO
-G-LF
8-Pin SOIC
0°C to +70°C
Commercial
IPS15HI-SO
-G-LF
8-Pin SOIC
-40°C to +85°C
Industrial
IPS15H
VCC
ROHS /
NDRIVE
For detailed ordering information, see page 15
FUNCTIONAL BLOCK DIAGRAM
OVERV
OPTO
VCC
UNDER
VOLTAGE
LOCKOUT
PDRIVE
OVER
VOLTAGE
LOCKOUT
SW
THERMAL
SHUTDOWN
PWM
_
5V
REF1
VCC
+
SHUNT
REF2
IPS15H
FILTERS
COMPARATORS
ENB
_
R
REGULATOR
Bandgap
reference
Q
+
REF3
SOFT START
RBIAS
GND
Hiccup
Control
ENB
OSCILLATOR
GND
S
CURRENT
LIMITING
VCC
SW
NDRIVE
ISENSE
TYPICAL APPLICATION SCHEMATIC: AC in 90-265V, DC out 5V, Imax 600mA
L1
D3
TX1 EI/EE FERRITE
OUT+
330uH
Schottky
1A - 60V
Patented
Snubber Network
C4
120pF
600V
4
4.7uF
+
C2
BR1
390k
SMT
1K
1/2W
NMOSFET
1A, 600V
R10
4.3k
SMT
1
2
3
4
R2A
D2
1
430k
SMT
2 x 1N4148
+
C1
C3
4.7uF
400V
10uF
16V
+
2
U4
PDRV NDRV
ISENSE GND
VCC OPTO
RBIAS OVRV
R12
1.5k
SMT
C7
2.2
SMT
R5
8
7
6
5
U2
PrimaryGND
C6
470uF
16V
Loop Compensation
OUTPUT
U3
3
R11
330k
SMT
R17
10Meg
1/4W
OPTO Q817C
R4
R15
4.7K
10k
R10A
IPS15H
D3
BRIDGE
R14
Q1
R3
400V
3
Noise-Canceling Type
LP=1.5mH
LS=1.5microH
R2
+
INPUT
90V-270V AC
100k
SMT
C1
220pF
SMT
K
REF
2
1
A
TL431
R16
10k
SecondaryGND
OUT-
R11 and R12 to be adjusted for max line overvoltage protection
Figure 1
R4 controls max pick current
when the ISENSE pin voltage exceeds ~700 mv
R15 and R16 to be adjusted according to output voltage
Note: Original R2 has been split into R2 and R2A to double the voltage rating.
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
2 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
Hiccup mode:
The output power that triggers the hiccup mode is monitored from the line-side by sensing the MOSFET current
through the ISENSE resistor (R4 in the example of Fig.1). The hiccup mode doesn’t require any specific component
on the load-side. This mode called “hiccup” is a special “overload protection” mode where the IPS15H resets itself
when an overload condition is detected and which duration exceeds the maximum authorized time THdtc as described
below:
Approximatly THoff after power-up and when the IPS15H is fully operational, the output power is sensed to check an
overload condition present or not (“true” or “false”) . If it is “true” and remains “true” all over THdtc then the
IPS15H resets. Power supply re-establishes and after THoff time, the chip restarts monotoring the output power
through RSENSE and the “hiccup” mode could repeat itself as described.
If the overload condition is “false” or when it is true for less than THdtc, the IPS15H simply operates like the original
IPS10 / IPS15 flyback controllers.
Overload Condition:
An overload condition is defined by
PSout > PSmax Æ “true”;
PSout < PSmax Æ “false”;
PSout = SMPS output power (secondary);
PSmax = maximum authorized output power
delivered by the SMPS secondary.
Hiccup detect time THdtc and off time THoff:
THoff = time from start-up to PSOUT sensing;
THdtc = maximum detect time of overload
condition to trigger chip reset;
(THoff + THdtc)/ THoff. = hiccup duty cycle.
Note: Conditions of figure 2 were altered to
better show the “hiccup” operation mode.
Actual duty cycle will be
much less as indicated in formula below.
Figure 2: “Hiccup” mode in constant overload
Calculation of the output power “PSmax” that triggers the hiccup mode:
As explained above, when PSout > PSmax for more than THdtc time, hiccup mode starts. The previous formula could
also be seen from the primary as PSout = (PPout - losses) > PSmax where losses correspond to the overall losses
(schottky, transformer, MOSFET, snubber etc..). As a first approximation the losses could be estimated to 25% and
consequently 75% of primary power PPmax could be used.
PPout > (PSmax + losses) = ½ LpIpeak2F Æ Ipeak = 0.7V/RSENSE (0.7V = max ISENSE pin voltage, Ipeak = peak
MOSFET current).
PSmax /0.75 = ½ LpIpeak2F = ½ Lp (0.7V/RSENSE) 2F
This relation will help the SMPS designer to determine the 3 suitable parameters for their application: Lp = primary
inductance of TX transformer, RSENSE = ISENSE resistor, F = frequency of operation.
As in our example of Fig.1 with R4 = 2.2Ohm, Lp=1.5mH and F= 70KHz Æ Pout = 4W – losses ~ 3W. At 5V, the
overload condition is set “true” when Ipeak reaches approximatly 600mA.
Calculation of hiccup detect time (THdtc ) and off time (THoff )
THdtc is proportional to 1/F and typically is 7ms for Fnom=70KHz. To calculate THdtc at any other frequency, apply
7ms x Fnom/F1. Example: F1= 50KHz, Tdtc = 7ms x 70KHz/50KHz ~ 10ms
THoff ~ 6 x (R2 +R2A) x C3 . In the example of figure 1, with Vin =90V, THoff ~ 6 x 1.5MΩ x 10μF ~ 1s
Vin RMS
90V
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
3 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
Calculation of the max value of the output capacitor C6 (see Fig.1):
During the power-up phase, the output capacitor C6 needs to be fully charged within the hiccup detect time THdtc
otherwise the IPS15H would detect an overload condition which doesn’t exist and will enter hiccup mode. Please
calculate the maximum capacitor value suitable for your application by applying:
C6 max ≤ Lp x 385 x (Ipeak)2
Where Lp = primary inductance of TX transformer
2
Vout
Ipeak = maximum peak current in the MOSFET
Vout = output DC voltage of the SMPs
In the schematic page 2, the calculation of C6 max shows an absolute max value of ~ 2300μF.
PROTECTION AGAINST OPTOCOUPLER FAILURE USING A SIMPLE LOW-COST, LOW-POWER ZENER
D3
TX1 EI/EEFERRITE
OUT+
Schottky
1A - 60V
DC IN
FAIL-SAFE
PROTECTION
Noise-Canceling Type
LP=1.5mH
LS=1.5microH
R10
4.3k
SMT
1
2
3
4
VCC IN
10k
R10A
U4
PDRV NDRV
ISENSE GND
VCC OPTO
RBIAS OVRV
R12
1.5k
SMT
C7
8
7
6
5
U2
R5
PrimaryGND
Loop Compensation
Z1
ONE
3
R11
330k
SMT
C6
470uF
16V
U3
OPTO Q817C
2.2
SMT
R17
10Meg
1/4W
IPS15H
R4
R15
4.7K
+
NMOSFET
1A, 600V
FROM
OPTOCOUPLER
FAILURE
R14
Q1
100k
SMT
C1
220pF
SMT
REF
2
LOW-POWER
ZENER
REQUIRED
K
1
A
TL431
R16
10k
SecondaryGND
OUT-
Figure 3
When adding a zener diode with a voltage slightly above the maximum output DC operating voltage, the SMPS will
automatically enter hiccup mode if the optocoupler fails open.
Thanks to entering hiccup mode, the average power dissipation in the diode will be limited to a small fraction of
what the SMPS could deliver when the feedback loop is opened. This is why a low-power zener is sufficient for full
protection.
Therefore the combination of the IPS15H hiccup capability with a simple low-power low-cost ouput diode brings a
very affordable protection against optocoupler failure, avoiding destruction of the load and the SMPS itself. A
simple replacement of the optocoupler then will bring the SMPS back to normal operation.
As already described in the front page, in hiccup mode the average current drops well below 100mA. A very lowpower rated zener can be therefore selected according to the intrinsic voltage required by the application. This will
allow the SMPS to remain overloaded indefinitely without any reliability or safety concerns.
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
4 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
PIN DESCRIPTION
Number
Name
Description
1
PDRIVE
Internal P drive terminal to be connected to the gate of the outside power
MOSFET. (The rising edge can be adjusted with an external resistor)
2
ISENSE
3
VCC
4
RBIAS
5
OVERV
6
OPTO
7
GND
8
NDRIVE
MOSFET current sensing. Any voltage over 700 mv @ 25°C on this pin for
an internally defined number of clock cycles, will trigger “hiccup” mode.
IC positive supply. The chip behaves like a 9.7 volts zener diode.
External RBIAS connection to set the operating frequency.
Line over-voltage lock-out pin. @ 25°C a voltage over 4V on this pin will
pull the MOSFET gate to GND.
Feedback input
Ground
Internal N drive terminal to be connected to the gate of the outside power
MOSFET. (The falling edge can be adjusted with an external resistor)
IN-PLUG® IPS15H FUNCTIONAL DESCRIPTION
As the IPS15, the IN-PLUG® IPS15H is a PWM controller for flyback switching power supply applications. This
version has been designed to protect SMPSs from overload conditions with a minimum circuitry and minimum load
side losses. The principal features are:
- Low quiescent Current (half of IPS15);
- Max output power (overload) controlled from line-side;
- Shunt regulator to allow the maximum flexibility to power the chip;
- Protections against overheating, and line over-voltage;
- Under-voltage lockout;
- Precise oscillator with externally adjustable frequency;
- On-chip filters for the loop compensation and the over-current sensing;
- Soft start and over-voltage shut-down to protect the MOSFET;
- Separate MOSFET P and N drivers to adjust rising and falling edge independently.
The shunt regulator operates like a zener diode, keeping the chip supply voltage around 9.7 volts. At start-up the
chip stays in stand-by mode until the voltage of VCC reaches about 9.7 volts. During this phase, the consumption is
of the order of 60 μA and the IC being partially disabled can only handle a maximum of 1mA of supply current.
When the 9.7 volts are reached, the driver starts providing gate pulses. The chip will go back to the stand-by mode if
the supply voltage decreases down to ~8 volts. The overall chip consumption in normal operation is about 350 μA,
not counting the current required to drive the MOSFET gate.
For domestic application, the chip can be supplied from the rectified line voltage through a resistor. In such case, the
resistor has to be sized to drive enough current to the chip.
For international applications, the IC gets the start current from a resistor connected to the rectified line voltage
(~70 μA) then, after the first gate pulse, the patented modified snubber network (*) provides the additional current to
keep the chip running.
The opto pin is pulled to internal 5V through an on-chip resistor which value is 60KΩ nominal, allowing a maximal
duty cycle of 66 %. During start-up, the duty cycle is controlled by the internal soft start unit which smoothly
increases the MOSFET current up to its maximum, corresponding to 700mV developped across the sense resistor.
When the expected output voltage is reached, the optocoupler's led is driven, and the opto pin voltage decreases,
reducing the duty cycle to a controlled value. The initial current limiting protection of the original IPS15 that was
simply turning-off the MOSFET when the ISENSE pin voltage exceeds ~700 mv, is now used to trigger the
“hiccup mode” when the condition is present for a maximum time defined by an internal IPS15H digital counter.
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
5 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
This overload condition is sensed from the line-side by monitoring the MOSFET current. The MOSFET must be
allowed to operate at maximum current for the SMPS to properly start and respond to transient conditions. When
the “time of operation at maximum current” counter overflows, it is in an overload condition and the circuit enters
"Hiccup Mode". The peak current in the load is still high in order to be able to return to normal mode, but the duty
cycle is so low that the average current drops below 100mA therefore allowing the SMPS to remain overloaded
indefinitely without any reliability or safety concerns.
The line-side voltage limiting protection operates by turning-off the MOSFET when the OVERV pin voltage
exceeds ~4V.
(*) US Patent # 6,233,165 - Royalty free licence for IN-PLUG® Customers.
IPS15H normal operation at 15W*
AC 110V - IPS15H normal operation at 5W*
Vout
Vout
Isense
Isense
Drain
Drain
IPS15H normal operation at 15W*
AC 250V - IPS15H normal operation at 5W*
Vout
Vout
Isense
Isense
Drain
Drain
*
* Together with a 1A, 600V MOSFET.
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
6 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
OUTPUT POWER CAPABILITY
Part Number
IPS15H
Package
DIP-8 / SOIC-8
230V AC or 115V AC w/ Doubler
Up to 70W (1)
85 – 285V AC
Up to 30W (1)
Note (1): Governed by size and package of external MOSFET
ELECTRICAL CHARACTERISTICS
ABSOLUTE MAXIMUM RATING
Characteristics
Shunt regulator max ICC in normal operation (pin 3)
- see fig 6-
Value
UNITS
50
mA
1
mA
All analog inputs (pin 2, 4, 5, 6)
Min= -0.3, Max= +6.3V
V
Peak drive output current (pin1)
Source=100, Sink=170
mA
Shunt regulator max ICC at start-up
Junction to case thermal resistance RθJ-C
PDIL = 42, SOIC = 45
Junction to PCB thermal resistance RθJ-A
PDIL = 125, SOIC =155
Power dissipation for TA <= 70°C
PDIL = 640, SOIC = 500
Operating junction temperature
- 40 to 150
Storage temperature range
- 55 to 150
Lead temperature (3 mm from case for 5 sec.)
PARAMETER
mW
°C
260
TEST CONDITIONS
@ 25°C unless specified
°C / W
PARAMETERS
UNITS
MIN.
TYP.
MAX.
ICC = 1 to 30 mA
9.2
9.7
10.5
V
1 to 30 mA
2
3
5
Ω
-
35
-
mA
-
-
80
μΑ
VCC – 2.2
VCC - 1.5
VCC - 1.4
V
1.1
3.2
4.9
mA
@
80KHz
@ 150KHz
655
700
745
mV
-
30
-
μV/°C
3.85
4
4.15
V
-
30
-
clock cycles
-
900
-
ns
-
140
-
°C
Supply, bias & circuit protection
Shunt regulator voltage
Shunt regulator dynamic
resistance
Shunt regulator max peak
repetitive current
Min ICC to start oscillator
Under voltage lock-out
Min ICC to ensure continuous
operation
1A, 600V, 5 nC MOSFET
@ 20KHz
Current limiting sensing
voltage
Temperature coefficient of
current limiting
Overvoltage sensing voltage
Soft/start duration
Leading edge blanking
Thermal shutdown trip
temperature
0 to 700mV
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
7 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
ELECTRICAL CHARACTERISTICS (cont’d)
PARAMETER
PARAMETER
@ 25°C unless specified
PARAMETERS
UNITS
MIN.
TYP.
MAX.
30
80
150
KHz
550
170
80
KΩ
-1.5
-
1.5
%
-
66
0
-
%
%
-
7
-
ms
-
54
95
mV
Oscillator & PWM
Range of operating
frequencies
RBIAS values for above
frequencies (see figure 4)
Oscillator stability with
supply & temperature
(see figure 5 for average)
Maximum duty cycle
Minimum duty cycle
ICC = 5 mA
Temp = 0 to 70°C
Hiccup run time THdtc
F = 70 KHz* - see Note2
Hiccup off time THroff
Proportional to R2 x C3
See explanation page 3
Error amplifier
Sensitivity in mV / % of PWM
Voltage for max duty cycle
(On OPTO pin)
-
4
-
V
Voltage for min duty cycle
(On OPTO pin)
-
0.6
-
V
OPTO pin
40
60
80
KΩ
P gate driver saturation
10 mA (source)
-
-
1
V
N gate driver saturation
10 mA (sink)
-
-
0.6
V
Gate pull-down resistor
(internal)
280
400
520
KΩ
PDRIVE Rise time (10% to
90%)
240 pF load
-
150
-
ns
NDRIVE Fall time (10% to
90%)
240 pF load
-
75
-
ns
@ 20 KHz
-
-
100
nC
“
@ 80 KHz
-
-
50
nC
“
@ 150 KHz
-
-
15
nC
Input impedance
P & N Outputs to MOSFET gate
Max recommended total
external MOSFET charge
Note1: Electrical parameters, although guaranteed, are not all 100% tested in production.
* Note2: Detect time THdtc is proportional to 1/F. For example at 50KHz, detect time THdtc = 7ms x 70KHz /
50KHz = 10ms (full explanation page 3)
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
8 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
F ig u re 4 : F re q u e n c y vs R b ia s
190
170
Frequency (kHz)
150
130
110
90
70
50
30
10
0
50
100
150
200
250
300
350
400
450
500
550
R b ia s (k O h m )
Figure 5 Frequency drift vs tem perature
Frequency variation (%)
2.00
1.00
ICC=5mA
0.00
-1.00
-2.00
-20
-10
0
10
20
30
40
50
60
70
80
90
100
Tem perature (°C)
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
9 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
Figure 6: Shunt regulator V/I characteristics*
50
40
Icc (mA)-
30
20
10
0
0
2
4
6
8
10
12
14
Vcc (V)
* Note: Do not attempt to force more than 1mA into Vcc pin during start-up.
GOOD DESIGN PRACTICES
IPS15H and loop stability:
The IPS15H is intrinsically very fast and doesn’t participate to the loop stability. It only involves a comparator that
doesn’t bring any gain and exhibits a negligible phase shift.
It has been designed on purpose to allow its utilization in a large range of applications:
(a) Operating at frequencies up to 200 kHz and even above,
(b) Involving very different types of loop stability from "cycle skipping" where the loop is not compensated at all, to
good stability achieved through the utilization of a TL431 and finally superior transient response when using half of
the IPS25 feedback controller.
The loop compensation is entirely achieved on the load side and the feedback is performed by an optocoupler which
gain and dynamic response play an important role in the loop stability.
Precaution in selecting the optocoupler:
The optocoupler must be using a Phototransistor and NOT a Photodarlington. Most optocouplers of this type are
offered in a wide range of coupling efficiency, also called transfer ratio. Even the cheapest ones have a guaranteed
transfer ratio of the order of 100% meaning that 1mA of current in the IR LED creates approximately 1mA of
current in the receiving phototransistor. The user should be able to design the loop to be stable even though the
actual transfer ratio differs by more than a factor of 3 (example from 100% to 300% or 50% to 150%).
Unfortunately optocouplers were not designed for low-current applications and this results in very bad speed and
saturation characteristics for the phototransistor which could become incredibly slow and create severe loop stability
problems should it be allowed to saturate hard in the application (the optocoupler could cause the IPS15H to skip
cycles due to the long time required by the opto transistor to go out of saturation).
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
10 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
In the example of figure 1, the output voltage is 10 volts as defined by R15 and R16 and 2.5V at the Pin #1 of the TL431. The
cathode of the TL431 can go to a voltage as low as 2 Volts. The IR LED requires approximately 1 Volt which means that the
voltage drop across R14 could be up to 6 volts resulting in a maximum current of 700uA. This value is plentiful for the utilization
of a broad range of optocouplers and yet small enough to avoid hard saturation.
Loop stability with the TL431:
The TL431 has an enormous DC gain and will not ensure stability unless specific loop-compensation components
such as a RC network are added as indicated below.
The RC network should have a cut-off frequency at 100Hz to roll-off the gain at low frequencies but reach a
plateau around 100Hz and have enough AC gain at twice the line frequency and achieve a good line ripple
rejection.
This is achieved by the loop compensation network C7, R17 of figure1. The gain rolls off until the impedance of C7
reaches the value of R7. At much higher frequencies, the gain continue to roll-off due to the natural frequency
response of the TL431.
The goal is to reach a very low gain at the switching frequency.
If the addition of C7 & R17 with values as shown results in gain is too low, the values of R15 & R16 should be
reduced in proportion to lower the impedance at Pin #1 of TL 431. Alternately, if the gain is too high the values of
R17 should be reduced and C7 re-adjusted accordingly to maintain the required cut-off frequency.
Criteria to calculate the network :
1) R17 must be much higher than the input resistance of TL431 constituted by R16//R15=5K Æ 68Kohm OK.
2) F=100Hz=1/(2 x 3.14 x R17 x C7) gives approximately 22,000 pF for C7.
Discontinuous operation:
Check discontinuous mode of operation of the transformer (see application note AN-IPS02 page 2 for details)
to ensure that the Flyback SMPS is indeed operating in discontinuous mode in the entire range of Input Voltages
and Output Current. The response of the SMPS drastically changes in continuous mode, it gets considerably slower
which requires a totally different loop compensation technique. Remember that it is very difficult to ensure loop
stability with a simple schematic when the SMPS is allowed to transition between Discontinuous and Continuous
modes.
MOSFET driver protection:
The MOSFET driver has been sized to be capable of driving power MOSFETs featuring a total gate charge up to
100nC.
The MOSFET should be turned-on relatively slowly and turned-off much faster. These 2 parameters can be
independently adjusted through the external resistors R10 (pin1) and R10A (pin8).
The minimum value of these resistors should be 50Ω in order to reduce EMI and minimize the noise injection which
could result from Miller-capacitance kick-back during transient conditions.
See application note AN-IPS-02 for EMI reduction techniques.
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
11 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
ADDITIONAL RECOMMENDATIONS:
For best results in low power off-line SMPSs with the IPS15H, the following MOSFET features are recommended:
- Low gate charge (max 50 nC).
- 400 V breakdown voltage for domestic use (USA / Japan).
- 600V breakdown voltage for European use (800V when transformer leakage inductance is very small).
- 1, 2 or 3A depending on the maximum output power.
Examples of suitable MOSFETS:
- IXYS PolarHT™ and Polar HV™ MOSFET series: IXTY1R4N60P, IXTY2N60P, IXTY3N60P
- Fairchild MOSFET series: FQPF1N60, FQPF 2N60, FQPF 3N60.
- Infineon COOLMOSTM series: SPD01N60S5, SPD02N60S5, SPD03N60S5.
- Motorola MOSFET series: MTP1N60, MTP2N60, MTP3N60.
- SGS-Thomson MOSFET series: STD1NB60, STD2NB60, STD3NB60.
- Etc…
Notes:
- Due to the rapid evolution of MOSFET technologies, please check for current models when designing a new
SMPS.
- PolarHT™ and Polar HV™ are trademarks of IXYS corporation
- COOLMOSTM is a trademark of Infineon.
TRANSFORMER CHARACTERISTICS:
(a) Transformer design:
E-core with suitable gap to prevent saturation or distributed-gap toroid. Primary inductance of 1.5 mH is very
typical in 5 -10W applications with 5V output DC:
Turn ratio = 9 for 220V input or universal 85V – 265V.
Turn ratio = 7 for 100-120V AC input (Japan and USA)
(b) Transformer phasing:
Check the phase indicated in figure 1. Also refer to applications notes AN-IPS-01 and AN-IPS-02.
SNUBBER NETWORK:
With reference to figure 1, R2 + R2A provide the start-up current for the chip. C3 is being charged through
R2+R2A. Once the chip supply voltage is high enough, the gate drive starts and the chip is then powered by the
modified snubber network presently being patented by our company.
The snubber values may have to be optimized for different specific operating conditions:
- R3 could be reduced to 100 ohms and sometimes eliminated.
- C4 could be increased to 200pF and sometimes more.
Depending on the characteristics of the transformer, essentially leakage inductance and distributed capacitance, the
snubber network shown in figure 1, may not be efficient enough to reduce the voltage spikes when operating at 20W
or above. Please refer to applications notes AN-IPS-01 and AN-IPS-02 design tips or EMI reduction techniques, or
feel free to contact our technical support for assistance.
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
12 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
POWER SHUT-DOWN SOLUTIONS for STAND-BY REQUIREMENTS:
For low-power stand-by requirements, the primary circuitry can be shut-down by pulling the IPS15H VCC pin
“LOW” through a 100Ω resistor.
This can be easily done using a:
• Simple switch
• PNP transistor
• NPN transistor
L1
D3
TX1 EI/EE FERRITE
OUT+
330uH
Schottky
1A - 60V
Patented
Snubber Network
C4
90V-270V AC
+
4
C2
4.7uF
BR1
750k
SMT
1K
1/2W
NMOSFET
1A, 600V
R10
4.3k
SMT
1
2
3
4
R2A
D2
1
750k
SMT
2 x 1N4148
+
C1
C3
4.7uF
400V
10uF
16V
+
2
R12
1.5k
SMT
U4
PDRV NDRV
ISENSE GND
VCC OPTO
RBIAS OVRV
C7
2.2
SMT
8
7
6
5
U2
OUTPUT
U3
R11
330k
SMT
C6
470uF
16V
Loop Compensation
3
R5
R17
10Meg
1/4W
OPTO Q817C
R4
R15
4.7K
10k
R10A
IPS15H
D3
BRIDGE
R14
Q1
R3
400V
3
Noise-Canceling Type
LP=1.5mH
LS=1.5microH
R2
120pF
600V
+
INPUT
PrimaryGND
100k
SMT
C1
220pF
SMT
K
REF
2
1
A
TL431
R16
10k
SecondaryGND
OUT-
SHUT-DOWN
SOLUTIONS
1,2 or 3
Figure 7
Solution 1:
simple switch, close = off
100Ω resistor
mandatory
100 Ω
Solution 2:
PNP transistor, low = off
(low = less than 4V)
100Ω resistor
optional
100 Ω
Solution 3:
NPN transistor, high = off
100Ω resistor
optional
100 Ω
high = off
close = off
low = off
When the "LOW" state is released, the VCC is naturally re-established, re-activating the IPS15H.
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
13 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
PACKAGE DIMENSIONS
PLASTIC DIP-8
PLASTIC SOIC-8
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
14 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
ORDERING INFORMATION
Part-Number
IPS XXXH
C – YY – G-LF - TR
Tape and Reel
TR : Tape & Reel
TU : Tube
Note1 : Default or not specified
is « tube ».
Note2 : Does not appear on
package marking.
IN-PLUG® Controller Series
Flyback
Feedback
PFC
Push-Pull
LED Driver
ROHS + Pb-Free
Package Type
Controller Type
Flyback: 10 series
Feedback: 20 series
PFC: 100 series
Push-Pull: 200 series
LED Driver: 400 series
“H” with hiccup overload protection
D : DIP8
SO : SOIC8
(For production with a new date code, after January
2006, the package type will not appear anymore on
package marking)
Temperature Range
C : Commercial (0, +70°C)
I : Industrial (-40°C. +85°C)
Note : Default or not specified is <commercial>
Example of Marking
AAI
IPS15HC
YYWW
Non-Green Package
AAI G-LF
IPS15HC
YYWW
Green ROHS + Pb-Free Package
(Note : For production with a new date code, since January 2006, the package type does not appear anymore on package
marking)
This ordering information is for commercial and industrial standard IN-PLUG® controllers ONLY. For custom controllers or for
automotive and military temperature ranges, call AAI’s sales representative.
© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
- Revision 10 – April 02, 2007
15 / 16
IN-PLUG® IPS15H Datasheet – Rev.10 – Hiccup flyback Controller – Easy Opto Failsafe Protection
The following is a brief overview of certain terms and conditions of sale of product. For a full and complete copy of all
the General Terms and Conditions of Sale, visit our webpage http://www.asicadvantage.com/terms.htm.
LIMITED WARRANTY
The product is warranted that it will conform to the applicable specifications and be free of defects for one year.
Buyer is responsible for selection of, use of and results obtained from use of the product. Buyer indemnifies and
holds ASIC Advantage, Inc. harmless for claims arising out of the application of ASIC Advantage, Inc.’s products to
Buyer’s designs. Applications described herein or in any catalogs, advertisements or other documents are for
illustrative purposes only.
CRITICAL APPLICATIONS
Products are not authorized for use in critical applications including aerospace and life support applications. Use of
products in these applications is fully at the risk of the Buyer. Critical applications include any system or device
whose failure to perform can result in significant injury to the user.
LETHAL VOLTAGES
Lethal voltages could be present in the applications. Please comply with all applicable safety regulations.
INTELLECTUAL PROPERTY RIGHTS AND PROPRIETARY DATA
ASIC Advantage, Inc. retains all intellectual property rights in the products. Sale of products does not confer on Buyer
any license to the intellectual property. ASIC Advantage, Inc. reserves the right to make changes without notice to
the products at any time. Buyer agrees not to use or disclose ASIC Advantage Inc.’s proprietary information without
written consent.
TRADEMARKS AND PATENTS
- IN-PLUG® is a registered trademark of ASIC Advantage, Inc.
- AAI’s modified snubber network is patented under the US Patent # 6,233,165. IN-PLUG® Customers are granted
a royalty-free licence for its utilization, provision the parts are purchased factory direct or from an authorized agent.
PROTECTION FOR CUSTOM IN-PLUG® SOLUTIONS
When AAI accepts to design and manufacture IN-PLUG® products to Buyer’s designs or specifications, buyer has
certain obligations to provide defense in a suit or proceeding claiming infringement of a patent, copyright or trademark
or for misappropriation of use of any trade secrets or for unfair competition.
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Buyer agrees that at all times it will comply with all applicable federal, state, municipal, and local laws, orders and
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TITLE AND DELIVERY
All shipments of goods shall be delivered ExWorks, Sunnyvale, CA, U.S.A. Title in the goods shall not pass to Buyer
until ASIC Advantage, Inc. has received in full all amounts owed by Buyer.
LATEST DATASHEET UPDATES
For the latest datasheet updates, visit our web page: http://www.in-plug.com/datasheets.htm.
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Copyrights and all other proprietary rights in the Content rests with ASIC Advantage Inc. (AAI) or its licensors. All
rights in the Content not expressly granted herein are reserved. Except as otherwise provided, the Content published
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ASIC Advantage INC.
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Tel: (1) 408-541-8686 Fax: (1) 408-541-8675
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© Copyright 2003-2007 - ASIC Advantage, Inc. – All rights reserved
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