PRODUCT DATABOOK 1996/1997
UC184xA/284xA/384xA
C
URRENT
M
ODE
PWM C
ONTROLLER
P
R O D U C T I O N
D
A T A
S
H E E T
CHARACTERISTIC CURVES
FIGURE 1.
— OSCILLATOR FREQUENCY vs. TIMING
RESISTOR
V
REF
8
Oscillator Frequency - (Hz)
1M
C
T
= 1nF
R
T
R
T
/C
T
4
C
T
GROUND 5
C
T
= 2.2nF
100k
10k
C
T
= 4.7nF
For R
T
> 5k, f
»
0
300
1.0k
3.0k
10.0k
30.0k
100k
1.72
R
T
C
T
Note: Output drive frequency is half the oscillator frequency for
the UCx844A/5A devices.
R
T
- (ohms)
FIGURE 2.
— MAXIMUM DUTY CYCLE vs. TIMING RESISTOR
100.0
Maximum Duty Cycle - (%)
80.0
60.0
40.0
20.0
0
300
1.0k
3.0k
10.0k
30.0k
100k
R
T
- (ohms)
Copyright © 1995
Rev. 1.2 12/95
5
MICROSEMI [ MICROSEMI CORPORATION ]
