UC2842/3/4/5-UC3842/3/4/5
ELECTRICAL CHARACTERISTICS
(continued)
Symbo l
Parameter
T est Cond ition s
UC284X
UC384X
Min. T yp. Max. Min. T yp. Max.
15
7.8
9
7.0
16
8.4
10
7.6
17
9.0
11
8.2
14.5
7.8
8.5
7.0
16
8.4
10
7.6
17.5
9
11.5
8.2
Unit
UNDER-VOLTAGE LOCKOUT SECTION
Start Threshold
X842/4
X843/5
Min Operating Voltage
After Turn-on
X842/4
X843/5
PWM SECTION
Maximum Duty Cycle
X842/3
X844/5
Minimum Duty Cycle
TOTAL STANDBY CURRENT
I
st
I
i
V
iz
Start-up Current
Operating Supply Current
Zener Voltage
V
PIN2
= V
PIN3
= 0V
I
i
= 25mA
0.5
11
34
1
20
0.5
11
34
1
20
mA
mA
V
93
46
97
48
100
50
0
93
47
97
48
100
50
0
%
%
%
V
V
V
V
N otes :
2. These parameters, although guaranteed, are not 100% tested in production.
3. Parameter measured at trip point of latch with V
PIN2
= 0.
4. Gain defined as :
∆
V
PIN1
A=
; 0
≤
V
PIN3
≤
0.8 V
∆
V
PIN3
5. Adjust V
i
above the start threshold before setting at 15 V.
6. Output frequency equals oscillator frequency for the UC3842 and UC3843.
Output frequency is one half oscillator frequency for the UC3844 and UC3845.
4/11
STMICROELECTRONICS [ STMICROELECTRONICS ]
