UC1842/3/4/5
UC2842/3/4/5
UC3842/3/4/5
Unless otherwise stated, these specifications apply for −55°C ≤ TA ≤ 125°C for the
UC184X; −40°C ≤ TA ≤ 85°C for the UC284X; 0°C ≤ TA ≤ 70°C for the 384X; VCC =
ELECTRICAL CHARACTERISTICS:
15V (Note 5); RT = 10k; CT = 3.3nF, TA=TJ.
UC1842/3/4/5
UC2842/3/4/5
UC3842/3/4/5
UNITS
PARAMETER
TEST CONDITION
MIN
TYP
MAX
MIN
TYP
MAX
Output Section
Output Low Level
ISINK = 20mA
ISINK = 200mA
0.1
1.5
13.5
13.5
50
0.4
2.2
0.1
1.5
13.5
13.5
50
0.4
2.2
V
V
Output High Level
ISOURCE = 20mA
13
12
13
12
V
ISOURCE = 200mA
V
Rise Time
TJ = 25°C, CL = 1nF (Note 2)
TJ = 25°C, CL = 1nF (Note 2)
150
150
150
150
ns
ns
Fall Time
50
50
Under-voltage Lockout Section
Start Threshold
X842/4
X843/5
X842/4
X843/5
15
7.8
9
16
8.4
10
17
9.0
11
14.5
7.8
8.5
7.0
16
8.4
10
17.5
9.0
V
V
V
V
Min. Operating Voltage
After Turn On
11.5
8.2
7.0
7.6
8.2
7.6
PWM Section
Maximum Duty Cycle
X842/3
X844/5
95
46
97
48
100
50
0
95
47
97
48
100
50
0
%
%
%
Minimum Duty Cycle
Total Standby Current
Start-Up Current
0.5
11
34
1
0.5
11
34
1
mA
mA
V
Operating Supply Current
VPIN 2 = VPIN 3 = 0V
ICC = 25mA
17
17
VCC Zener Voltage
30
30
Note 2:
Note 3:
.
These parameters, although guaranteed, are not 100% tested in production.
Parameter measured at trip point of latch with VPIN 2 = 0
∆ VPIN 1
Note 4:
Gain defined as: A =
; 0 ≤ VPIN 3 ≤ 0.8V.
∆ VPIN 3
Note 5:
Note 6:
Adjust VCC above the start threshold before setting at 15V.
Output frequency equals oscillator frequency for the UC1842 and UC1843.
Output frequency is one half oscillator frequency for the UC1844 and UC1845.
ERROR AMP CONFIGURATION
Error Amp can Source or Sink up to 0.5mA
4
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