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TOP264-271
TOPSwitch-JX
Family
®
Integrated Off-Line Switcher with EcoSmart Technology
for Highly Efficient Power Supplies
®
Product Highlights
EcoSmart
®
- Energy Efficient
•
Energy efficient over entire load range
•
No-load consumption below 100 mW at 265 VAC
•
Up to 750 mW standby output power for 1 W input at 230 VAC
High Design Flexibility for Low System Cost
•
Multi-mode PWM control maximizes efficiency at all loads
•
132 kHz operation reduces transformer and power supply size
•
66 kHz option for highest efficiency requirements
•
Accurate programmable current limit
•
Optimized line feed-forward for line ripple rejection
•
Frequency jittering reduces EMI filter cost
•
Fully integrated soft-start for minimum startup stress
•
725 V rated MOSFET
•
Simplifies meeting design derating requirements
Extensive Protection Features
•
Auto-restart limits power delivery to <3% during overload faults
•
Output short-circuit protection (SCP)
•
Output over-current protection (OCP)
•
Output overload protection (OPP)
•
Output overvoltage protection (OVP)
•
User programmable for hysteretic/latching shutdown
•
Simple fast AC reset
•
Primary or secondary sensed
•
Line undervoltage (UV) detection prevents turn-off glitches
•
Line overvoltage (OV) shutdown extends line surge withstand
•
Accurate thermal shutdown with large hysteresis (OTP)
Advanced Package Options
•
eDIP
™
-12 package:
•
Low profile horizontal orientation for ultra-slim designs
Output Power Table
Product
5
TOP264VG
TOP265VG
TOP266VG
TOP267VG
TOP268VG
TOP269VG
TOP270VG
TOP271VG
PCB Copper Area
1
230 VAC ±15%
4
85-265 VAC
Open
Open
2
Adapter
Adapter
2
Frame
3
Frame
3
21 W
34 W
12 W
22.5 W
22.5 W
36 W
15 W
25 W
24 W
39 W
17 W
28.5 W
27.5 W
44 W
19 W
32 W
30 W
48 W
21.5 W
36 W
32 W
51 W
22.5 W
37.5 W
34 W
55 W
24.5 W
41 W
36 W
59 W
26 W
43 W
Product
5
TOP264EG/VG
TOP265EG/VG
TOP266EG/VG
TOP267EG/VG
TOP268EG/VG
TOP269EG/VG
TOP270EG/VG
TOP271EG/VG
Metal Heat Sink
1
230 VAC ±15%
4
85-265 VAC
Open
Open
2
Adapter
Adapter
2
Frame
3
Frame
3
30 W
62 W
20 W
43 W
40 W
81 W
26 W
57 W
60 W
119 W
40 W
86 W
85 W
137 W
55 W
103 W
105 W
148 W
70 W
112 W
128 W
162 W
80 W
120 W
147 W
190 W
93 W
140 W
177 W
244 W
118 W
177 W
AC
IN
+
DC
OUT
-
D
V
CONTROL
TOPSwitch-JX
S
X
F
C
PI-5578-090309
Figure 1.
Typical Flyback Application.
•
•
•
Heat transfer to both PCB and heat sink
•
Optional external heat sink provides thermal impedance
equivalent to a TO-220
eSIP
®
-7C package:
•
Vertical orientation for minimum PCB footprint
•
Simple heat sink mounting using clip provides thermal
impedance equivalent to a TO-220
Extended creepage to DRAIN pin
Heat sink is connected to SOURCE for low EMI
•
Description
TOPSwitch-JX cost effectively incorporates a 725 V power
MOSFET, high voltage switched current source, multi-mode
PWM control, oscillator, thermal shutdown circuit, fault
protection and other control circuitry onto a monolithic device.
Table 1. Output Power Table.
Notes:
1. See Key Application Considerations section for more details.
2. Minimum continuous power in a typical non-ventilated enclosed adapter measured at +50 °C ambient temperature.
3. Minimum continuous power in an open frame design at +50 °C ambient temperature.
4. 230 VAC or 110/115 VAC with doubler.
5. Packages: E: eSIP-7C, V: eDIP-12. See Part Ordering Information section.
www.powerint.com
March 2010
TOP264-271
Section List
Functional Block Diagram
....................................................................................................................................... 3
Pin Functional Description
...................................................................................................................................... 3
TOP264-271 Functional Description
........................................................................................................................ 4
CONTROL (C) Pin Operation .................................................................................................................................... 5
Oscillator and Switching Frequency.......................................................................................................................... 5
Pulse Width Modulator ............................................................................................................................................ 5
Maximum Duty Cycle ............................................................................................................................................... 6
Error Amplifier .......................................................................................................................................................... 6
On-Chip Current Limit with External Programmability ............................................................................................... 6
Line Undervoltage Detection (UV) ............................................................................................................................. 6
Line Overvoltage Shutdown (OV) .............................................................................................................................. 7
Hysteretic or Latching Output Overvoltage Protection (OVP)..................................................................................... 7
Line Feed-Forward with DC
MAX
Reduction ................................................................................................................ 8
Remote ON/OFF ..................................................................................................................................................... 8
Soft-Start ................................................................................................................................................................. 9
Shutdown/Auto-Restart (for OCP, SCP, OPP) ......................................................................................................... 10
Hysteretic Over-Temperature Protection (OTP) ....................................................................................................... 10
Bandgap Reference ............................................................................................................................................... 10
High-Voltage Bias Current Source .......................................................................................................................... 10
Typical Uses of FREQUENCY (F) Pin
...................................................................................................................... 12
Typical Uses of VOLTAGE MONITOR (V) and EXTERNAL CURRENT LIMIT (X) Pins
.......................................... 13
Application Examples
.............................................................................................................................................. 15
Low No-load, High Efficiency, 65 W, Universal Input Adapter Power Supply
..................................................................... 15
Very low No-load, High Efficiency, 30 W, Universal Input, Open Frame, Power Supply .............................................................. 17
Key Application Considerations
.............................................................................................................................. 18
TOPSwitch-JX vs.TOPSwitch-HX
........................................................................................................................
. 18
TOP264-271 Design Considerations ..................................................................................................................... 18
TOP264-271 Layout Considerations ...................................................................................................................... 20
Quick Design Checklist .......................................................................................................................................... 21
Design Tools .......................................................................................................................................................... 21
Product Specifications and Test Conditions
.......................................................................................................... 23
Typical Performance Characteristics
.................................................................................................................... 30
Package Outlines
.................................................................................................................................................... 34
Part Ordering Information
........................................................................................................................................ 35
2
Rev. B 03/10
www.powerint.com
TOP264-271
CONTROL (C)
Z
C
V
C
0
DRAIN (D)
INTERNAL
SUPPLY
-
1
SHUNT REGULATOR/
ERROR AMPLIFIER
-
+
+
5.8 V
4.8 V
-
SOFT START
K
PS(UPPER)
+
5.8 V
VI
(LIMIT)
I
FB
CURRENT
LIMIT
ADJUST
INTERNAL UV
COMPARATOR
-
+
ON/OFF
÷
16
SHUTDOWN/
AUTO-RESTART
STOP LOGIC
K
PS(LOWER)
-
+
EXTERNAL CURRENT
LIMIT (X)
VOLTAGE
MONITOR (V)
V
BG
+ V
T
CURRENT LIMIT
COMPARATOR
SOURCE (S)
CONTROLLED
TURN-ON
GATE DRIVER
1V
V
LINE
SENSE
OVP OV/
UV
DC
MAX
DC
MAX
HYSTERETIC
THERMAL
SHUTDOWN
STOP
SOFT
START
D
MAX
CLOCK
S
R
Q
OSCILLATOR
WITH JITTER
66k/132k
F REDUCTION
FREQUENCY (F)
LEADING
EDGE
BLANKING
F REDUCTION
SOFT START
I
FB
PWM
I
PS(UPPER)
I
PS(LOWER)
OFF
K
PS(UPPER)
K
PS(LOWER)
PI-4511-012810
SOURCE (S)
Figure 2.
Functional Block Diagram (E and V Package).
Pin Functional Description
DRAIN (D) Pin:
High-voltage power MOSFET DRAIN pin. The internal start-up
bias current is drawn from this pin through a switched high-
voltage current source. Internal current limit sense point for
drain current.
CONTROL (C) Pin:
Error amplifier and feedback current input pin for duty cycle
control. Internal shunt regulator connection to provide internal
bias current during normal operation. It is also used as the
connection point for the supply bypass and auto-restart/
compensation capacitor.
EXTERNAL CURRENT LIMIT (X) Pin:
Input pin for external current limit adjustment remote
ON/OFF and device reset. A connection to SOURCE pin
disables all functions on this pin.
VOLTAGE MONITOR (V) Pin:
Input for OV, UV, line feed forward with DC
MAX
reduction, output
overvoltage protection (OVP), remote ON/OFF. A connection to
the SOURCE pin disables all functions on this pin.
FREQUENCY (F) Pin:
Input pin for selecting switching frequency 132 kHz if connected
to SOURCE pin and 66 kHz if connected to CONTROL pin.
SOURCE (S) Pin:
Output MOSFET source connection for high voltage power return.
Primary side control circuit common and reference point.
NO CONNECTION (NC) Pin:
Internally not connected, floating potential pin.
E Package (eSIP-7C)
V Package (eDIP-12)
S 12
Exposed Pad
S 11
(Hidden)
S 10
Internally
Connected to
S 9
SOURCE Pin
1V
2X
3C
4F
5 NC
6D
S8
S7
12345 7
VXCF S D
PI-5568-083109
Figure 3.
Pin Configuration (Top View).
3
www.powerint.com
Rev. B 03/10
TOP264-271
PI-5579-012210
+
R
LS
4 MΩ
V
UV
= I
UV
× R
LS
+ V
V
(I
V
= I
UV
)
V
OV
= I
OV
× R
LS
+ V
V
(I
V
= I
OV
)
For R
LS
= 4 MΩ
Auto-Restart
78
Duty Cycle (%)
Slope = PWM Gain
V
UV
= 102.8 VDC
V
OV
= 451 VDC
DC
MAX
@100 VDC = 76%
DC
MAX
@375 VD
C = 41%
C
DC
Input
Voltage
D
V
CONTROL
S
X
R
IL
12 kΩ
For R
IL
= 12 kΩ
I
LIMIT
= 61%
See Figure 35 for
other resistor values
(R
IL
) to select different
I
LIMIT
values.
-
Figure 4.
CONTROL
Current
Package Line Sense and Externally Set Current Limit.
TOP264-271 Functional Description
Like TOPSwitch-HX, TOP264-271 is an integrated switched
mode power supply chip that converts a current at the control
input to a duty cycle at the open drain output of a high voltage
power MOSFET. During normal operation the duty cycle of the
power MOSFET decreases linearly with increasing CONTROL
pin current as shown in Figure 5.
In addition to the three terminal TOPSwitch features, such as
the high voltage start-up, the cycle-by-cycle current limiting,
loop compensation circuitry, auto-restart and thermal shut-
down, the TOP264-271 incorporates many additional functions
that reduce system cost, increase power supply performance
and design flexibility. A patented high voltage CMOS technology
allows both the high-voltage power MOSFET and all the low
voltage control circuitry to be cost effectively integrated onto a
single monolithic chip.
Three terminals, FREQUENCY, VOLTAGE-MONITOR, and
EXTERNAL CURRENT LIMIT have been used to implement
some of the new functions. These terminals can be connected
to the SOURCE pin to operate the TOP264-271 in a TOPSwitch-
like three terminal mode. However, even in this three terminal
mode, the TOP264-271 offers many transparent features that do
not require any external components:
1. A fully integrated 17 ms soft-start significantly reduces or
eliminates output overshoot in most applications by sweeping
both current limit and frequency from low to high to limit the
peak currents and voltages during start-up.
2. A maximum duty cycle (DC
MAX
) of 78% allows smaller input
storage capacitor, lower input voltage requirement and/or
higher power capability.
3. Multi-mode operation optimizes and improves the power
supply efficiency over the entire load range while maintaining
good cross regulation in multi-output supplies.
4. Switching frequency of 132 kHz reduces the transformer size
with no noticeable impact on EMI.
5. Frequency jittering reduces EMI in the full frequency mode at
high load condition.
Drain Peak Current
To Current Limit Ratio (%)
100
55
25
CONTROL
Current
Full Frequency Mode
132
Low
Frequency
Mode
Frequency (kHz)
66
Jitter
30
I
CD1
I
B
I
C01
Variable
Frequency
Mode
Multi-Cycle
Modulation
I
C02
I
C03
I
COFF
CONTROL
Current
PI-5665-110609
Figure 5.
Control Pin Characteristics (Multi-Mode Operation).
6. Hysteretic over-temperature shutdown ensures thermal fault
protection.
7. Packages with omitted pins and lead forming provide large
drain creepage distance.
8. Reduction of the auto-restart duty cycle and frequency to
improve the protection of the power supply and load during
open loop fault, short circuit, or loss of regulation.
9. Tighter tolerances on I
2
f power coefficient, current limit
reduction, PWM gain and thermal shutdown threshold.
The VOLTAGE-MONITOR (V) pin is usually used for line sensing
by connecting a 4 MW resistor from this pin to the rectified DC
high voltage bus to implement line overvoltage (OV), under-
voltage (UV) and dual-slope line feed-forward with DC
MAX
reduction. In this mode, the value of the resistor determines the
OV/UV thresholds and the DC
MAX
is reduced linearly with a dual
slope to improve line ripple rejection. In addition, it also
provides another threshold to implement the latched and
4
Rev. B 03/10
www.powerint.com
TOP264-271
hysteretic output overvoltage protection (OVP). The pin can
also be used as a remote ON/OFF using the I
UV
threshold.
The EXTERNAL CURRENT LIMIT (X) pin can be used to reduce
the current limit externally to a value close to the operating peak
current, by connecting the pin to SOURCE through a resistor.
This pin can also be used as a remote ON/OFF input.
The FREQUENCY (F) pin sets the switching frequency in the full
frequency PWM mode to the default value of 132 kHz when
connected to SOURCE pin. A half frequency option of 66 kHz
can be chosen by connecting this pin to the CONTROL pin
instead. Leaving this pin open is not recommended.
CONTROL (C) Pin Operation
The CONTROL pin is a low impedance node that is capable of
receiving a combined supply and feedback current. During
normal operation, a shunt regulator is used to separate the
feedback signal from the supply current. CONTROL pin voltage
V
C
is the supply voltage for the control circuitry including the
MOSFET gate driver. An external bypass capacitor closely
connected between the CONTROL and SOURCE pins is
required to supply the instantaneous gate drive current. The
total amount of capacitance connected to this pin also sets the
auto-restart timing as well as control loop compensation.
When rectified DC high voltage is applied to the DRAIN pin
during start-up, the MOSFET is initially off, and the CONTROL
pin capacitor is charged through a switched high voltage
current source connected internally between the DRAIN and
CONTROL pins. When the CONTROL pin voltage V
C
reaches
approximately 5.8 V, the control circuitry is activated and the
soft-start begins. The soft-start circuit gradually increases the
drain peak current and switching frequency from a low starting
value to the maximum drain peak current at the full frequency
over approximately 17 ms. If no external feedback/supply
current is fed into the CONTROL pin by the end of the soft-start,
the high voltage current source is turned off and the CONTROL
pin will start discharging in response to the supply current
drawn by the control circuitry. If the power supply is designed
properly, and no fault condition such as open loop or shorted
output exists, the feedback loop will close, providing external
CONTROL pin current, before the CONTROL pin voltage has
had a chance to discharge to the lower threshold voltage of
approximately 4.8 V (internal supply undervoltage lockout
threshold). When the externally fed current charges the CONTROL
pin to the shunt regulator voltage of 5.8 V, current in excess of
the consumption of the chip is shunted to SOURCE through an
NMOS current mirror as shown in Figure 2. The output current
of that NMOS current mirror controls the duty cycle of the
power MOSFET to provide closed loop regulation. The shunt
regulator has a finite low output impedance Z
C
that sets the gain
of the error amplifier when used in a primary feedback
configuration. The dynamic impedance Z
C
of the CONTROL pin
together with the external CONTROL pin capacitance sets the
dominant pole for the control loop.
When a fault condition such as an open loop or shorted output
prevents the flow of an external current into the CONTROL pin,
the capacitor on the CONTROL pin discharges towards 4.8 V.
At 4.8 V, auto-restart is activated, which turns the output
MOSFET off and puts the control circuitry in a low current
standby mode. The high-voltage current source turns on and
charges the external capacitance again. A hysteretic internal
supply undervoltage comparator keeps V
C
within a window of
typically 4.8 V to 5.8 V by turning the high-voltage current
source on and off as shown in Figure 7. The auto-restart circuit
has a divide-by-sixteen counter, which prevents the output
MOSFET from turning on again until sixteen discharge/charge
cycles have elapsed. This is accomplished by enabling the
output MOSFET only when the divide-by-sixteen counter
reaches the full count (S15). The counter effectively limits
TOP264-271 power dissipation by reducing the auto-restart
duty cycle to typically 2%. Auto-restart mode continues until
output voltage regulation is again achieved through closure of
the feedback loop.
Oscillator and Switching Frequency
The internal oscillator linearly charges and discharges an
internal capacitance between two voltage levels to create a
triangular waveform for the timing of the pulse width modulator.
This oscillator sets the pulse width modulator/current limit latch
at the beginning of each cycle.
The nominal full switching frequency of 132 kHz was chosen to
minimize transformer size while keeping the fundamental EMI
frequency below 150 kHz. The FREQUENCY pin, when shorted
to the CONTROL pin, lowers the full switching frequency to
66 kHz (half frequency), which may be preferable in some cases
such as noise sensitive video applications or a high efficiency
standby mode. Otherwise, the FREQUENCY pin should be
connected to the SOURCE pin for the default 132 kHz.
To further reduce the EMI level, the switching frequency in the
full frequency PWM mode is jittered (frequency modulated) by
approximately ±2.5 kHz for 66 kHz operation or ±5 kHz for
132 kHz operation at a 250 Hz (typical) rate as shown in Figure 6.
The jitter is turned off gradually as the system is entering the
variable frequency mode with a fixed peak drain current.
Pulse Width Modulator
The pulse width modulator implements multi-mode control by
driving the output MOSFET with a duty cycle inversely
proportional to the current into the CONTROL pin that is in
excess of the internal supply current of the chip (see Figure 5).
The feedback error signal, in the form of the excess current, is
filtered by an RC network with a typical corner frequency of
7 kHz to reduce the effect of switching noise in the chip supply
current generated by the MOSFET gate driver.
To optimize power supply efficiency, four different control
modes are implemented. At maximum load, the modulator
operates in full frequency PWM mode; as load decreases, the
modulator automatically transitions, first to variable frequency
PWM mode, then to low frequency PWM mode. At light load,
the control operation switches from PWM control to multi-cycle-
modulation control, and the modulator operates in multi-cycle-
modulation mode. Although different modes operate differently
to make transitions between modes smooth, the simple
relationship between duty cycle and excess CONTROL pin
current shown in Figure 5 is maintained through all three PWM
5
www.powerint.com
Rev. B 03/10
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