2-74 Service Guide
2.9 Ambit DC-AC Inverter
This notebook uses two kinds of DC-AC inverters: One (T62.088.C) is designed for the 13.3-inch
TFT (LG LP133X1) LCD, the other (T62.055.C) for the 12.1-inch TFT (IBM ITSV50D) LCD.

2.9.1 T62.055C

2.9.1.1 Pin Diagram

CN2

CN1 T62.055.C 1
2
21
20 3
2
1

CN3

Figure 2-12 T62.055.C Pin Diagram
2.9.1.2 Pin Descriptions
Table 2-9T62.055.C Pin Descriptions
Pin Name Pin Type Pin No. Descriptions
CN1 connector signals
Vhi
Vlo O1
2This is the High voltage side of the Lamp. (The shorter wire to
lamp connects to this output.
Max lamp start voltage(Vrms): 1300
Typical lamp run voltage @25°C(Vrms): 650
Min open circuit voltage (Vrms): 1100
Max open circuit voltage(Vrms): 1500
CN2 connector signals
GND GND 1, 6 This the return signal for the input power and control signals and
is an extension of the system ground.
CNTADJ O2, 9 Contrast adjustment (reserved)
DCIN I3, 4, 5 This is the input DC voltage to supply the operating power.
Max value: 19VDC
Min value: 7 VDC
BRTADJ O7This is an analog signal in the range of 0 to 3 volts to control the
lamp current.
Vbrite = 1 volt, Lamp current = 50%±10% of Max.
Vbrite = 3volts, Lamp current = Max = 4.5mA
PANEL_ON I8A control pin to control on/off lamp. This input enable the
inverter operation (Lamp On) when high and disables the inverter
when low. This signal is output from a 3.3V CMOS device.
Max loading = 100uA
Logic Low = 0.8 volts Max.
Logic High =1.8 volts Min.
PWRLED O12 This signal is an open collector sink signal to drive LED1. The
LED current is limited by a series resistor of 1K.