UCC3808D-1
RC
4.99 k
Ω
4.99 k
Ω
432
Ω
0.1
µ
F10
µ
F
20 k
Ω
330 pF
86.6 k
Ω
0.01
µ
F
1 kV
N
S1
N
S2
N
P1
N
P2
680
µ
F 0.01
µ
F
470 pF
4700 pF
20 k
Ω
19.1 k
Ω
COMP
19.1 k
Ω
200
Ω
LOOP B
LOOP A
2.2
Ω
0.2
Ω
2 k
Ω
330 pF
1000 pF
62
Ω
62
Ω
1000 pF
2.2
Ω
51 k
Ω
1/4 W
0.47
µ
F4700
µ
F
V
IN
36 V TO 72 V
+
–
BYV
28–200
BYV
28–200
32CTQ030ER28
8:2
+
V
O
5 V 50 W
5678
4321
H11A1
4
5
6
3
2
1
U3
CURRENT
SENSE
PRIMARY
GROUND
–
IRF640
IRF640
20 k
Ω
2N2907
0.1
µ
F
240
Ω
0.1
µ
F
3
1
TL431
2
10
Ω
12
EF25 7
µ
H
1 mH
DF02SGICT
2.80 k
Ω
VDD OUTA OUTB GND
RCCSFBCOMP
UCC2808-1
,
UCC2808-2
,
UCC3808-1
,
UCC3808-2
SLUS168E –APR 1999–REVISED AUGUST 2015
UCCx808-x Low Power Current Mode Push-Pull PWM
1 Features 3 Description
The UCCx808-x is a family of BiCMOS push-pull,
1
• Dual Output Drive Stages in Push-Pull
high-speed, low-power, pulse-width modulators. The
Configuration
UCCx808 contains all of the control and drive circuitry
• 130-μA Typical Starting Current
required for offline or DC-to-DC fixed frequency
• 1-mA Typical Run Current
current-mode switching power supplies with minimal
external parts count.
• Operation to 1-MHz
• Internal Soft-Start
The UCCx808-x dual output drive stages are
arranged in a push-pull configuration. Both outputs
• On-Chip Error Amplifier With 2-MHz Gain
switch at half the oscillator frequency using a toggle
Bandwidth Product
flip-flop. The dead time between the two outputs is
• On-Chip VDD Clamping
typically 60 ns to 200 ns depending on the values of
• Output Drive Stages Capable Of 500-mA Peak
the timing capacitor and resistors, thus limiting each
output stage duty cycle to less than 50%.
Source Current, 1-A Peak Sink Current
Device Information
(1)
2 Applications
PART NUMBER PACKAGE BODY SIZE (NOM)
• Server and Desktop Power Supplies
UCC2808-1 SOIC (8) 4.90 mm × 3.91 mm
• Telecom Power Supplies
UCC2808-2
UCC3808-1
PDIP (8) 9.81 mm × 6.35 mm
• DC-DC Converters
UCC3808-2
• Switched-Mode Power Supplies
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Schematic
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
