LG LAC2900N Service Manual page 26

1-2. PIN FUNCTION (Note1)
Pin No. Pin name
1 GND Ground
2 FREG_B External Trs bass drive (Note4)
3 FREG_F FREG feedback terminal
4 ILMOUT 8.4V output for JLM/500mAmax
5 CTL4 FREG control terminal
6 CDOUT 8.0V output for CD/1.3Amax (Note4)
7 DSPOUT 3.3V output for DSP/250mAmax (Note4)
8 VB Battery
9 CTL3 ILM control terminal
10 AUDIOOUT 8.4V output for AUDIO/500mAmax (Note4)
11 CTL1 DSP, CD, Audio control terminal
12 EXTOUT High side output/600mAmax (Note4)
13 CTL2 EXT control terminal
14 VDDOUT 5.7V output for micro controller (Note4)
15 VBUP Back up
Note1. In the uper table. "On" means always On. "Off" means compulsory Off and "On/Off" means that it can control by con-
trol terminal.
Note2. Thermal protection circuit
A built-in thermal protection circuit (TSD:Thermal shut down) prevents thermal damage to the IC. All outputs except
VDD(pin14) and FREG (pin2&3) are switched off when the circuit operates, revert to the original state when the tem-
perature drops to a certain level.
Note3. Overvoltage protection circuit
The overvoltage protection circuit (surge protector) turns off all outputs without Vdd, when VB voltage is more than
about 21V. And the overvoltage protection circuit (surge protector) turns off Vdd output with other all outputs, when
VB voltage is more than about 26V. When the overvoltage protection operates on VB>=18V condition, the stand by
current increases.
Note4. Overcurrent protection circuit
FREG_B (pin2), ILMOUT (pin4), CDOUT (pin6), DSPOUT (pin7), AUDIOOUT (pin10), EXITOUT (pin12), VDDOUT
(pin14) output circuits are built-in overcurrent protection circuit based on the respective output current. These over-
current protection circuits limit the current with a curve shape of "7" in the voltage-current graph. This prevents IC
destruction due to overcurrent.
Function
2-19
Protection function
Normal
(Note2)
TSD On
operation
- -
On/Off On/Off
On/Off On/Off
On/Off Off
- -
On/Off Off
On/Off Off
- -
- -
On/Off Off
- -
On/Off Off
- -
On On
- -
(Note3) (Note3)
VB=24V VB=50V
- -
Off Off
Off Off
Off Off
- -
Off Off
Off Off
- -
- -
Off Off
- -
Off Off
- -
On Off
- -