OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
U
LTRA
-L
OW
S
TART
-U
P
C
URRENT
, C
URRENT
-M
ODE
PWM
LX1552/3/4/5
PRODUCT DATABOOK 1996/1997
5
Copyright © 1994
Rev. 1.0b
PRODUCTION DATA SHEET
GRAPH / CURVE INDEX
Characteristic Curves
FIGURE #
1. OSCILLATOR FREQUENCY vs. TIMING RESISTOR
2. MAXIMUM DUTY CYCLE vs. TIMING RESISTOR
3. OSCILLATOR DISCHARGE CURRENT vs. TEMPERATURE
4. OSCILLATOR FREQUENCY vs. TEMPERATURE
5. OUTPUT INITIAL ACCURACY vs. TEMPERATURE
6. OUTPUT DUTY CYCLE vs. TEMPERATURE
7. REFERENCE VOLTAGE vs. TEMPERATURE
8. REFERENCE SHORT CIRCUIT CURRENT vs. TEMPERATURE
9. E.A. INPUT VOLTAGE vs. TEMPERATURE
10.START-UP CURRENT vs. TEMPERATURE
11.START-UP CURRENT vs. SUPPLY VOLTAGE
12.START-UP CURRENT vs. SUPPLY VOLTAGE
13.DYNAMIC SUPPLY CURRENT vs. OSCILLATOR FREQUENCY
14.CURRENT SENSE DELAY TO OUTPUT vs. TEMPERATURE
15.CURRENT SENSE THRESHOLD vs. ERROR AMPLIFIER OUTPUT
16.START-UP THRESHOLD vs. TEMPERATURE
17.START-UP THRESHOLD vs. TEMPERATURE
18.MINIMUM OPERATING VOLTAGE vs. TEMPERATURE
19.MINIMUM OPERATING VOLTAGE vs. TEMPERATURE
20.LOW LEVEL OUTPUT SATURATION VOLTAGE DURING UNDER-
VOLTAGE LOCKOUT
21.OUTPUT SATURATION VOLTAGE vs. OUTPUT CURRENT and
TEMPERATURE
22.OUTPUT SATURATION VOLTAGE vs. OUTPUT CURRENT and
TEMPERATURE
FIGURE INDEX
Theory of Operation Section
FIGURE #
23.TYPICAL APPLICATION OF START-UP CIRCUITRY
24.REFERENCE VOLTAGE vs. TEMPERATURE
25.SIMPLIFIED SCHEMATIC OF OSCILLATOR SECTION
26.DUTY CYCLE VARIATION vs. DISCHARGE CURRENT
27.OSCILLATOR FREQUENCY vs. TIMING RESISTOR
28.MAXIMUM DUTY CYCLE vs. TIMING RESISTOR
29.CURRENT SENSE THRESHOLD vs. ERROR AMPLIFIER OUTPUT
Typical Applications Section
FIGURE #
30.CURRENT SENSE SPIKE SUPPRESSION
31.MOSFET PARASITIC OSCILLATIONS
32.ADJUSTABLE BUFFERED REDUCTION OF CLAMP LEVEL
WITH SOFT-START
33.EXTERNAL DUTY CYCLE CLAMP AND MULTI-UNIT SYCHRONIZATION
34.SLOPE COMPENSATION
35.OPEN LOOP LABORATORY FIXTURE
36.OFF-LINE FLYBACK REGULATOR
