Power ICs - DC-DC Isolated Power Supplies - PWM Controllers0 pages

Si9110/9111
Vishay Siliconix
Document Number: 70004
S-42037—Rev. H, 15-Nov-04
www.vishay.com
1
High-Voltage Switchmode Controllers
FEATURES
10- to 120-V Input Range
Current-Mode Control
High-Speed, Source-Sink Output Drive
High Efficiency Operation (> 80%)
Internal Start-Up Circuit
Internal Oscillator (1 MHz)
SHUTDOWN and RESET
Reference Selection
Si9110 - 1%
Si9111 - 10%
DESCRIPTION
The Si9110/9111 are BiC/DMOS integrated circuits designed
for use as high-performance switchmode controllers. A
high-voltage DMOS input allows the controller to work over a
wide range of input voltages (10- to 120-VDC). Current-mode
PWM control circuitry is implemented in CMOS to reduce
internal power consumption to less than 10 mW.
A push-pull output driver provides high-speed switching for
MOSPOWER devices large enough to supply 50 W of output
power. When combined with an output MOSFET and
transformer, the Si9110/9111 can be used to implement
single-ended power converter topologies (i.e., flyback,
forward, and cuk).
The Si9110/9111 are available in both standard and
lead (Pb)-free 14-pin plastic DIP and SOIC packages which
are specified to operate over the industrial temperature range
of -40
C to 85
C.
FUNCTIONAL BLOCK DIAGRAM
+
-
-
+
+
-
+
-
+
-
FB COMP DISCHARGE
OSC
14 13 9 8 7
2 V
Ref
Gen
R
S
Q
R
S
Q
SENSE
3
5
4
11
12
Current-Mode
Comparator
C/L
1.2 V
Undervoltage
8.1 V RESET
8.6 V
BIAS
Current
Sources
To
Internal
Circuits
10
1
6
2
Comparator
Error
Amplifier
VREF
VCC
+VIN
VCC
SHUTDOWN
4 V
OSC
OUT
OSC
IN
-VIN
Pre-Regulator/Start-Up
OUTPUT
To
VCC
Comparator
Clock (1/2 fOSC)