uc3844bvnguc3845bd ON Semiconductor, uc3844bvnguc3845bd Datasheet - Page 4

• Manufacturer Part Number: uc3844bvnguc3845bd
• Description: Current Mode Controller
• Manufacturer: ON Semiconductor

9. Adjust V
10. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.
2.55 V
2.45 V
ELECTRICAL CHARACTERISTICS
T
PWM SECTION
TOTAL DEVICE
2.5 V
A
Duty Cycle
Power Supply Current
Power Supply Zener Voltage (I
T
is the operating ambient temperature range that applies [Note 10], unless otherwise noted.)
Maximum (UC284XB, UC384XB)
Maximum
Minimum
Startup (V
Startup (V
Operating (Note 9)
8.0
5.0
2.0
0.8
low
80
50
20
10 k
= 0°C for UC3844B, UC3845B
= - 25°C for UC2844B, UC2845B
= - 40°C for UC3844BV, UC3845BV
NOTE: Output switches at
1/2 the oscillator frequency
CC
20 k
above the Startup threshold before setting to 15 V.
CC
CC
(UC384XBV)
Figure 4. Error Amp Small Signal
= 6.5 V for UCX845B,
=
versus Oscillator Frequency
14 V for UCX844B, BV)
f
For R
OSC
Figure 2. Timing Resistor
Characteristic
, OSCILLATOR FREQUENCY (kHz)
Transient Response
50 k
T
u 5 Kf X 1.72
0.5 ms/DIV
CC
100 k
= 25 mA)
UC3844B, UC3845B, UC2844B, UC2845B
R
200 k
T
(V
C
CC
T
= 15 V [Note 9], R
T
V
A
T
high
A
CC
V
= 25°C
500 k
= -1.0
V
T
A
= 15 V
CC
= + 70°C for UC3844B, UC3845B
= + 85°C for UC2844B, UC2845B
= +105°C for UC3844BV, UC3845BV
= 25°C
http://onsemi.com
= 15 V
1.0 M
Symbol
DC
DC
T
I
V
CC
(max)
(min)
4
= 10 k, C
Z
3.0 V
2.5 V
2.0 V
75
70
65
60
55
50
10 k
T
Ä Ä Ä Ä Ä
Ä Ä Ä Ä Ä
Ä Ä Ä Ä Ä
Ä Ä Ä Ä Ä
Ä Ä Ä Ä Ä
Min
= 3.3 nF. For typical values T
47
30
1. C
2. C
3. C
4. C
5. C
6. C
7. C
-
-
-
-
T
T
T
T
T
T
T
UC284XB
= 10 nF
= 5.0 nF
= 2.0 nF
= 1.0 nF
= 500 pF
= 200 pF
= 100 pF
20 k
Figure 5. Error Amp Large Signal
Typ
0.3
48
12
36
-
-
versus Oscillator Frequency
f
Figure 3. Output Deadtime
OSC
Transient Response
, OSCILLATOR FREQUENCY (kHz)
Max
0.5
50
17
-
0
-
50 k
1.0 ms/DIV
100 k
Min
47
46
30
-
-
-
A
UC384XB, XBV
= 25°C, for min/max values
200 k
Typ
0.3
48
48
12
36
-
1
Max
V
A
T
0.5
50
50
17
A
CC
V
0
-
500 k
= 25°C
= -1.0
= 15 V
2
6
5
3
4
Unit
mA
7
1.0 M
%
V