LG StudioWorks 570LE Service Manual page 42

PIN FUNCTIONS
PIN DIP-18 PIN SO-20
11 12
10 11
9 10
18 20
7,8 8,9
2,3 2,3
12 13
16 18
4,5,6 4,5,6,7
13,14,15 14,15,16,17
1 1
17 19
KIA431
1: REFERENCE
2: ANODE
3: CATHODE
1
3
2
NAME
COMP E/A output to be used for frequency compensation
INH A logic signal (active high) disables the device (sleep mode operation).
If not used it must be connected to GND; if floating the device is disabled.
BOOT A capacitor connected between this pin and the output allows to drive the
internal D-MOS.
SYNC Input/Output synchronization.
Vcc Not regulated DC input voltage
OUT Stepdown regulator output.
VFB Stepdown feedback input. Connecting directly this pin to the output 3.3V
and 5.1V are obtained; a voltage divider is requested for higher output
voltages. For voltage below 3.3V see note **
V5.1 Reference voltage externally available.
GND Signal ground
OSC An external resistor connected between the unregulated input voltage and
Pin 1 and a capacitor connected from Pin 1 to ground fixes the switching
frequency. (Line feed forward is automatically obtained)
SS Soft start time constant. A capacitor connected between this terminal and
ground determinates the soft start time.
Programmable Shunt Regulator
- 41 -
L4973V3-L4973V5
L4973D3-L4973D5
DESCRIPTION
2.5V
Reference
(R)
Cathode
(K)
Anode (A)