TOP266KG Power Integrations, TOP266KG Datasheet - Page 4

• Manufacturer Part Number: TOP266KG
• Description: IC OFFLINE SWITCHER 39W 58W
• Manufacturer: Power Integrations
• Series: TOPSwitch®-JXr

Specifications of TOP266KG

• Output Isolation: Isolated
• Frequency Range: 66 ~ 132kHz
• Voltage - Output: 725V
• Power (watts): 39W
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 12-BSOP (0.350", 8.89mm Width) Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 596-1399

Figure 5.
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 6.
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
2. A maximum duty cycle (DC
3. Multi-mode operation optimizes and improves the power
4. Switching frequency of 132 kHz reduces the transformer size
5. Frequency jittering reduces EMI in the full frequency mode at
Rev. C 11/10
4
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.
storage capacitor, lower input voltage requirement and/or
higher power capability.
supply efficiency over the entire load range while maintaining
good cross regulation in multi-output supplies.
with no noticeable impact on EMI.
high load condition.
Voltage
Input
Package Line Sense and Externally Set Current Limit.
DC
+
-
TOP264-271
D
S
R
CONTROL
LS
MAX
X
12 kΩ
R
V
) of 78% allows smaller input
IL
4 MΩ
C
V
V
DC
DC
For R
UV
OV
MAX
MAX
For R
= I
= I
V
V
See Figure 37 for
other resistor values
(R
I
LIMIT
I
LS
UV
OV
LIMIT
@100 VDC = 76%
@375 VD
UV
OV
IL
) to select different
= 4 MΩ
= 102.8 VDC
= 451 VDC
IL
× R
× R
values.
= 12 kΩ
= 61%
LS
LS
+ V
+ V
C = 41%
V
V
(I
(I
V
V
= I
= I
UV
OV
)
)
6. Hysteretic over-temperature shutdown ensures thermal fault
7. Packages with omitted pins and lead forming provide large
8. Reduction of the auto-restart duty cycle and frequency to
9. Tighter tolerances on I
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
reduction. In this mode, the value of the resistor determines the
OV/UV thresholds and the DC
slope to improve line ripple rejection. In addition, it also
provides another threshold to implement the latched and
Figure 6.
protection.
drain creepage distance.
improve the protection of the power supply and load during
open loop fault, short-circuit, or loss of regulation.
reduction, PWM gain and thermal shutdown threshold.
100
132
78
55
25
66
30
Control Pin Characteristics (Multi-Mode Operation).
I
Full Frequency Mode
CD1
Auto-Restart
I
B
Jitter
2
f power coefficient, current limit
I
C01
MAX
Slope = PWM Gain
is reduced linearly with a dual
Frequency
Variable
I
Mode
C02
www.powerint.com
I
C03
I
COFF
Frequency
PI-5665-110609
Multi-Cycle
Modulation
CONTROL
CONTROL
Mode
MAX
CONTROL
Low
Current
Current
Current