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the Infineon Technologies Companies and Representatives worldwide: see our webpage at http://
www.infineon.com.
CoolMOS™, CoolSET™ are trademarks of Infineon Technologies AG.
Edition 2004-01-28
Published by Infineon Technologies AG,
The information herein is given to describe certain components and shall not be considered as warr anted characteristics.
Terms of delivery and rights to technical change reserved.
We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding
circuits, descriptions and charts stated herein.
Infineon Technologies is an approved CECC manufacturer.
Information
For further information on technology, delivery terms and conditions and prices please contact your nearest
Infineon Technologies Office in Germany or our Infineon Technolog ies Representatives worldwide (see address
list).
Warnings
Due to technical requirements components may contain dangerous substances. For information on the types in
question please contact your nearest Infineon Technologies Office.
Infineon Technologies Components may only be used in life-support devices or systems with the ex press written
approval of Infineon Technologies, if a failure of such components can reasona bly be expe cted to cause the f ailure
of that life-support device or system, or to aff ect t he safety or effectiveness of that device or system. Life support
devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain
and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may
be endangered.
Off-Line SMPS Current Mode Controller
with integrated 650V/800V
CoolSET™-F2
Product Highlights
• Best in class in DIP8, DIP7, TO220 packages
• No heatsink required for DIP8, DIP7
• Lowest standby power dissipation
• Enhanced protection functions all with
Auto Restart Mode
• Isolated drain package for TO220
• Increased creepage distance for TO220 packages
Features
• 650V/800V avalanche rugged CoolMOS™
• Only few external components required
• Input Vcc Undervoltage Lockout
• 67kHz/100kHz switching frequency
• Max duty cycle 72%
• Low Power Standby Mode to meet
European Commission Requirements
• Thermal Shut Down with Auto Restart
• Overload and Open Loop Protection
• Overvoltage Protection during Auto Restart
• Adjustable Peak Current Limitation via
external resistor
• Overall tolerance of Current Limiting < ±5%
• Internal Leading Edge Blanking
• User defined Soft Start Soft Switching for low EMI
Typical Application
R
VCC
Power
Management
Protection Unit
Start-up
PWM Controller
Current Mode
Precise Low Tolerance
Peak Current Limitation
85 ... 270 VAC
SoftS
C
Soft Start
FB
Feedback
Low Power
StandBy
Soft-Start Control
PWM-Controller
CoolSET™-F2
Description
The second generation CoolSET™-F2 provides several
special enhancements to satisfy the needs for low power
standby and protection features. In standby mode
frequency reduction is used to lower the power
consumption and support a stable output voltage in this
mode. The frequency reduction is limited to 20kHz/21.5
kHz to avoid audible noise. In case of failure modes like
open loop, overvoltage or overload due to short circuit the
device switches in Auto Restart Mode which is controlled by
the internal protection unit. By means of the internal precise
peak current limitation the dimension of the transformer and
the secondary diode can be lower which leads to more cost
efficiency.
5VCCController Supply Voltage
6SoftSSoft-Start
7FBFeedback
1)
at Tj = 110°C
650V1) CoolMOS™ Drain
650V1) CoolMOS™ Source
Package P-TO220-6-46/47
1
234567
SoftS (Soft Start & Auto Restart Control)
This pin combines the function of Soft Start in case of
Start Up and Auto Restart Mode and the controlling of
the Auto Restart Mode in case of an error detection.
FB (Feedback)
The information about the regulation is provided by the
FB Pin to the internal Protection Unit and to t he internal
PWM-Comparator to control the duty cycle.
Isense (Current Sense)
The Current Sense pin senses the voltage developed
on the series resistor inserted in the source of the
integrated CoolMOS™. When Isense reaches the
internal threshold of the Current Limit Comparator, the
Driver output is disabled. By this means the Over
Current Detection is realized.
Furthermore the current information is provided for the
PWM-Comparator to realize the Current Mode.
Drain (Drain of integrated CoolMOS™)
Pin Drain is the connection to the Drain of the internal
CoolMOS
VCC (Power supply)
This pin is the positiv supply of the IC. The operating
range is between 8.5V and 21V.
To provide overvoltage protection the driver gets
disabled when the voltage becomes higher than 16.5V
during Start Up Phase.
GND (Ground)
This pin is the ground of the primary side of the SMPS.
TM
.
Drain
Isense
GND
VCC
SoftS
FB
Figure 3Pin Configuration (top view)
Datasheet V4.57Jan 2004
2Representative Blockdiagram
OUT
-
+
V
Converter
DC Output
Snubber
Drain
CoolMOS™
Gate
Driver
Q
Q
S
Clock
Reset
R
PWM-Latch
G4
norm
-f
standby
f
Spike
SQ
Blanking
G3
PWM
Comparator
Q
R
Error-Latch
s
5
G2
Soft-Start
Soft Start
Comparator
0.72
Duty Cycle Max
max
Duty Cycle
Oscillator
6.5V
4.8V
5.3V
4.0V
Voltage
Reference
Internal Bias
Power Management
13.5V
Reset
Lockout
Power-Down
Line
C
Undervoltage
VCC
C
Power-Up
8.5V
G1
CoolSET™-F2
Representative Blockdiagram
Sense
R
Isense
D1
10k
220ns
Blanking
Leading Edge
csth
V
Comparator
Current-Limit
C5
0.3V
osc
f
norm
f
f
Optocoupler
ICE2Bxxxx
Compensation
Propagation-Delay
Current Limiting
ICE2Axxxx
x3.65
0.8V
Improved Current Mode
PWM OP
FB
U
standby
Standby Unit
67kHz
20kHz
100kHz
21.5kHz
norm
standby
f
f
Start-up
R
85 ... 270 VAC
VCC
C1
4.0V
16.5V
6.5V
C4
C3
>140°C
j
T
Thermal Shutdown
4.8V
5.3V
5.6V
Soft-Start
R
SoftS
FB
R
6.5V
T1
Soft-Start
C
Protection Unit
FB
GND
CoolSET™-F2
C2
Figure 4Representative Blockdiagram
Datasheet V4.58Jan 2004
3Functional Description
3.1Power Management
CoolSET™-F2
Functional Description
3.2Improved Current Mode
Main Line (100V-380V)
R
Start-Up
Primary Winding
C
VCC
VCC
Power Management
SoftS
C
Soft-Start
Undervoltage
Lockout
8.5V
Pow er-D own
Reset
Power-Up
Reset
R
T1
13.5V
6.5V
Soft-S ta rt
Intern al
Bias
Voltage
Reference
RSQ
Q
Error-Latch
Soft-S ta rt C o m para to r
Error-D ete ction
6.5V
5.3V
4.8V
4.0V
PWM-Latch
Figure 5Power Management
The Undervoltage Lockout monitors the external
supply voltage V
current consumption is max. 55µA. When the SMPS is
plugged to the main line the current through R
charges the external Capacitor C
exceeds the on-threshold V
circuit and the voltage reference are switched on. After
that the internal bandgap generates a reference
voltage V
avoid uncontrolled ringing at switch-on a hysteresis is
implemented which means that switch-off is only after
active mode when Vcc falls below 8.5V.
In case of switch-on a Power Up Reset is done by
reseting the internal error-latch in the protection unit.
When V
internal reference is switched off and the Power Down
reset let T1 discharging the soft-start capaci tor C
at pin SoftS. Thus it is ensu re d th at at ev ery s wi tch- on
the voltage ramp at pin SoftS starts at zero.
REF
falls below the off-threshold V
VCC
. In case the IC is inactive the
VCC
Start-up
. When V
VCC
=13.5V the internal bias
CCon
VCC
=6.5V to supply the internal circuits. To
=8.5V the
CCoff
Soft-Start
Soft-Start Com parator
FB
PW M-Latch
RSQ
Driver
PW M Com parator
Q
0.8V
PWM OP
x3.65
Isense
Improved
Current Mode
Figure 6Current Mode
Current Mode means that the duty cycle is controlled
by the slope of the primary current. This is done by
comparison the FB signal with the amplified current
sense signal.
Amplified Current Signal
FB
0.8V
Driver
T
on
t
t
Figure 7Pulse Width Modulation
In case the amplified current sense signal exceeds the
FB signal the on-time T
reseting the PWM-Latch (see Figure 7).
of the driver is finished by
on
Datasheet V4.59Jan 2004
The primary current is sensed by the external series
resistor R
CoolMOS™. By means of Current Mode the regulation
of the secondary voltage is insensitive on line
variations. Line variation causes varition of the
increasing current slope which controls the duty cycle.
The external R
the maximum source current of the integrated
inserted in the source of the integrated
Sense
allows an individual adjustment of
Sense
CoolMOS™.
Soft-Start Com parator
PWM Comparator
FB
PW M-Latch
OSC
0.3V
C5
G a te Drive r
O scillato r
V
0.8V
10k
Ω
x3.65
T
2
R
1
V
1
C
20pF
1
PWM O P
Voltage Ramp
Figure 8Improved Current Mode
To improve the Current Mode during light load
conditions the amplified current ramp of the PWM-OP
is superimposed on a voltage ramp, which is built by
the switch T
low pass filter composed of R
Figure 9). Every time the oscillator shuts down for max.
duty cycle limitation the switch T2 is closed by V
When the oscillator triggers the Gate Driver T2 is
opened so that the voltage ramp can start.
In case of light load the amplified current ramp is to
small to ensure a stable regulation. In that case the
Voltage Ramp is a well defined signal for the
comparison with the FB-signal. The duty cycle is then
controlled by the slope of the Voltage Ramp.
By means of the Compa rator C5, the Gate Driver is
switched-off until the voltage ramp exceeds 0.3V. It
allows the duty cycle to be reduced continously till 0%
by decreasing V
, the voltage source V1 and the 1st order
2
below that threshold.
FB
and C1(see Figure 8,
1
OSC
.
CoolSET™-F2
Functional Description
V
OSC
max.
Duty Cycle
Voltage Ramp
0.8V
FB
0.3V
Gate Driver
Figure 9Light Load Conditions
3.2.1PWM-OP
The input of the PWM-OP is applied over the internal
leading edge blanking to the external sense resistor
connected to pin ISense. R
R
Sense
source current into a sense voltage. The sense voltage
is amplified with a gain of 3.65 by PWM OP. The output
of the PWM-OP is connected to the voltage source V1.
The voltage ramp with the superimposed amplified
current singal is fed into the positive inputs of the PWMComparator, C5 and the Soft-Start-Comparator.
Sense
3.2.2PWM-Comparator
The PWM-Comparator compares the sensed current
signal of the integrated C oolMOS
signal V
external optocoupler or external transistor in
combination with the internal pullup resistor R
provides the load information of the feedback circuitry.
When the amplified current signal of the integrated
CoolMOS™ exceeds the signal V
(see Figure 10). VFB is created by an
FB
Comparator switches off the Gate Driver.
TM
with the feedback
FB
t
t
t
converts the
and
FB
the PWM-
Datasheet V4.510Jan 2004
6.5V
R
FB
FB
Soft-Start Com parator
PW M-Latch
PW M Com parator
0.8V
Optocoupler
PWM OP
Ise n s e
x3.65
Improved
Current Mode
Figure 10 PWM Controlling
3.3Soft-Start
V
So ftS
5.6V
5.3V
T
So ft-Start
G a te Drive r
t
t
Figure 11 Soft-Start Phase
The Soft-Start is realized by the internal pullup resistor
and the external Capacitor C
R
Soft-Start
Figure 2). The Soft-Start voltage V
charging the external capacitor C
is generated by
SoftS
Soft-Start
(see
Soft-Start
by the internal
CoolSET™-F2
Functional Description
pullup resistor R
compares the voltage at pin SoftS at the negative input
with the ramp signal of the PWM-OP at the positive
input. When Soft-Start voltage V
Feedback voltage V
the pulse width by reseting the PWM-Latch (see Figure
11). In addition to Start-Up, Soft-Start is also activated
at each restart attempt during Auto Restart. By means
of the above mentioned C
defined by the user. The Soft-Start is finished when
exceeds 5.3V. At that time the Protection Unit is
V
SoftS
activated by Comparator C4 and senses the FB by
Comparator C3 wether the voltage is below 4.8V which
means that the voltage on the secondary side of the
SMPS is settled. The internal Zener Diode at SoftS with
breaktrough voltage of 5.6V is to prevent the internal
circuit from saturation (see Figure 12).
6.5V
5.6V
So ftS
6.5V
5.3V
4.8V
R
FB
FB
Figure 12 Activation of Protection Unit
The Start-Up time T
voltage V
Start Phase T
C
Soft Start–
By means of Soft-Start there is an effective
minimization of current and voltage stresses on the
integrated CoolMOS™, the clamp circuit and the output
overshoot and prevents saturation of the transformer
during Start-Up.
is settled must be shorter than the Soft-
OUT
Soft-Start
. The Soft-Start-Comparator
Soft-Start
the Soft-Start-Comparator limits
FB
SoftS
the Soft-Start can be
Soft-Start
Power-Up Reset
R
Sof t-S ta rt
C4
Erro r-L atc h
G2
C3
Clock
PWM-Latch
within the converter output
Start-Up
(see Figure 13).
T
Soft Start–
------------------------------------- -=
R
Soft Start–
1.69×
is less than
RSQ
Q
RSQ
Gate
Driver
Q
Datasheet V4.511Jan 2004
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