UC1842/3/4/5
UC2842/3/4/5
UC3842/3/4/5
ELECTRICAL CHARACTERISTICS:
Unless otherwise stated, these specifications apply for
−55°C ≤
T
A
≤
125°C for the
UC184X;
−40°C≤
T
A
≤
85°C for the UC284X; 0°C
≤
T
A
≤
70°C for the 384X; V
CC
=
15V (Note 5); R
T
= 10k; C
T
=3.3nF, T
A
=T
J.
UC1842/3/4/5
UC2842/3/4/5
MIN
Output Section
Output Low Level
Output High Level
Rise Time
Fall Time
Under-voltage Lockout Section
Start Threshold
Min. Operating Voltage
After Turn On
PWM Section
Maximum Duty Cycle
Minimum Duty Cycle
Total Standby Current
Start-Up Current
Operating Supply Current
V
PIN 2
= V
PIN 3
= 0V
0.5
11
1
17
30
0.5
11
34
1
17
mA
mA
V
X842/3
X844/5
95
46
97
48
100
50
0
95
47
97
48
100
50
0
%
%
%
X842/4
X843/5
X842/4
X843/5
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
9.0
11.5
8.2
V
V
V
V
I
SINK
= 20mA
I
SINK
= 200mA
I
SOURCE
= 20mA
I
SOURCE
= 200mA
T
J
= 25°C, C
L
= 1nF (Note 2)
T
J
= 25°C, C
L
= 1nF (Note 2)
13
12
0.1
1.5
13.5
13.5
50
50
150
150
0.4
2.2
13
12
0.1
1.5
13.5
13.5
50
50
150
150
0.4
2.2
V
V
V
V
ns
ns
TYP
MAX
UC3842/3/4/5
MIN
TYP
MAX
UNITS
PARAMETER
TEST CONDITION
I
CC
= 25mA
30
34
V
CC
Zener Voltage
Note 2: These parameters, although guaranteed, are not 100% tested in production.
Note 3: Parameter measured at trip point of latch with V
PIN 2
= 0.
Note 4: Gain defined as:
∆
V
PIN
1
A
=
; 0
≤
V
PIN
3
≤
0.8V.
∆
V
PIN
3
Note 5: Adjust V
CC
above the start threshold before setting at 15V.
Note 6: 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
TI [ TEXAS INSTRUMENTS ]
