TK75003D

Manufacturer Part NumberTK75003D
DescriptionPWM CONTROLLER
ManufacturerTOKO, Inc
TK75003D datasheet
 


1
Page 1
2
Page 2
3
Page 3
4
Page 4
5
Page 5
6
Page 6
7
Page 7
8
Page 8
9
Page 9
10
Page 10
11
12
13
14
Page 1/14

Download datasheet (109Kb)Embed
Next
FEATURES
Power Factor Correction/Line Harmonics
Reduction to Meet IEC1000-3-2 Requirements
Optimized for Off-Line Operation
Maximum Duty Ratio 88% (typ.)
Frequency Reduction for Improved Overcurrent
Protection
Low Standby Current for Current-Fed Start-Up
Current-Mode or Voltage-Mode Control
Internal User-Adjustable Slope Compensation
Functionally Integrated & Simplified 5-Pin Design
DESCRIPTION
The TK75003 is a simple primary side controller optimized
for off-line switching power supplies including power factor
correctors. It is suitable for both voltage-mode and current-
mode control and has advanced features not available in
controllers with a
higher pin count. The key to full
functionality in a 5-pin design is that the current signal and
the error signal are added together and fed into the
feedback pin. A sawtooth current flowing out of the feedback
pin provides a slope compensation ramp (in current-mode
applications) or a PWM ramp (in voltage-mode
applications), in proportion to the resistance terminating
that pin. If the sum of the current sense signal, error signal
and ramp signal exceeds the Overcurrent Detector
threshold indicating that the Current Control Detector has
lost control of the switch current, the charging current of
the timing capacitor will be reduced to about 25% for the
remainder of the clock period. The reduced charging
current causes no more than a one-third reduction in
switching frequency, effectively preventing short-circuit
current runaway.
ORDERING INFORMATION
TK75003D
TEMP. CODE (OPTIONAL)
I: -40 to +85 C
January 1999 TOKO, Inc.
APPLICATIONS
Power Factor Correction Converters
Off-Line Power Supplies
Industrial Power Supplies
Telecom Power Supplies
Off-Line Battery Chargers
I CT
C T
146 µA
Tape/Reel Code
Temperature Code
TAPE/REEL CODE
FB
MG: Magazine
TK75003
PWM CONTROLLER
TK75003
DRV
GND
GND
C T
Note: Pins 2 and 3 must be externally
connected for proper operation.
BLOCK DIAGRAM
BANDGAP
REFERENCE
I CHG
205 µA
10.5 V
OSCILLATOR
f CLK
I DS
I FR
2 mA
R
FREQUENCY
Q
REDUCTION
LATCH
S
PWM LATCH
SLOPE
COMPENSATION
S
Q
OVERCURRENT
R
DETECTOR
1.35 V
CURRENT
CONTROL
DETECTOR
0.98 V
GND
V CC
NC
NC
FB
V CC
UVLO
14.5 V
17.5 V
DRV
Page 1

TK75003D Summary of contents