L6565 Datasheet, PDF (1/17 Pages) STMicroelectronics – QUASI-RESONANT SMPS CONTROLLER

L6565
QUASI-RESONANT SMPS CONTROLLER
s QUASI-RESONANT (QR) ZERO-VOLTAGE-
SWITCHING (ZVS) TOPOLOGY
s LINE FEED FORWARD TO DELIVER
CONSTANT POWER vs. MAINS CHANGE
s FREQUENCY FOLDBACK FOR OPTIMUM
STANDBY EFFICIENCY
s PULSE-BY-PULSE & HICCUP-MODE OCP
s ULTRA-LOW START-UP (< 70µA) AND
QUIESCENT CURRENT (< 3.5mA)
s DISABLE FUNCTION (ON/OFF CONTROL)
s 1% PRECISION (@ T_j = 25°C) INTERNAL
REFERENCE VOLTAGE
s ±400mA TOTEM POLE GATE DRIVER WITH
UVLO PULL-DOWN
s BLUE ANGEL, ENERGY STAR, ENERGY
2000 COMPLIANT
APPLICATIONS
s TV/MONITOR SMPS
s AC-DC ADAPTERS/CHARGERS
s DIGITAL CONSUMER
s PRINTERS, FAX MACHINES,
PHOTOCOPIERS AND SCANNERS
BLOCK DIAGRAM
1
INV
2.5V
COMP
2
-
+
VOLTAGE
REGULATOR
DIP8(Minidip)
SO-8
ORDERING NUMBERS:
L6565N
L6565D
DESCRIPTION
The L6565 is a current-mode primary controller IC,
specifically designed to build offline Quasi-resonant
ZVS (Zero Voltage Switching at switch turn-on) fly-
back converters.
Quasi-resonant operation is achieved by means of a
transformer demagnetization sensing input that trig-
gers MOSFET's turn-on.
VFF
3
LINE VOLTAGE
FEEDFORWARD
2V
-+
-+
40K 4
CS
5pF
January 2003
8
VCC
20V
INTERNAL
SUPPLY
R1
RQ
SQ
+
UVLO
R2
-
VREF2
ZERO CURRENT
DETECTOR
Blanking
START
+
2.1V
BLANKING
1.6V
-
Hiccup-mode
OCP
DRIVER
Starter
STOP
STARTER
VCC
7
GD
Hiccup-mode
OCP
5
ZCD
DISABLE
6
GND
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