NEC 104PW161 Power inverter

NEC 104PW161 Power inverter

104PW161 inverter for LCD (Liquid crystal display) modules is composed of a DC/AC inversion circuit, a luminance control circuit and a boosting transformer.

The DC/AC inversion circuit inverts a direct current (DC) power supply into an altar current (AC) by  the center-tap transmitter circuit that used transistors.

The luminance control circuit can control the luminance of cold cathode lamps for LCD backlight unit. The boosting transformer is translated the low AC voltage that obtained from a DC/AC inversion circuit to the high AC voltage. Also the high AC voltage is outputted from a secondary side of the boosting transformer.


  • High AC voltage generator of cold cathode fluorescent lamp for LCD


  • Pulse width modulation circuit
  • Alert circuit for malfunction


Parameter Specification Unit
Board size 105.0 ± 0.5 (W) ´ 26.5 ± 0.5 (H) ´ 9.5 ± 0.5 (D) Note1 mm
Weight 20.0 (typ.), 23.0 (max.) g


Parameter Symbol Rating Unit Remarks

Combined load

Resistance RL 105 kW  



Ta = 25°C

Stray capacity CL 5 pF


Input voltage

Power supply for inverter VDDB 0 to +14.0 V
BRTI signal VBI 0 to +16.0 V
BRTC signal VBC -1.0 to VDDB+1.0 V
Storage temperature Tst -30 to +85 °C  



Operating temperature

Front surface TopF -10 to +70 °C
Rear surface TopR -10 to +70 °C




Relative humidity Note1







£ 95 % Ta £ 40°C
£ 85 % 40 < Ta £ 50°C
£ 70 % 50 < Ta £ 55°C
£ 60 % 55 < Ta £ 60°C
£ 50 % 60 < Ta £ 65°C
£ 42 % 65 < Ta £ 70°C
Absolute humidity Note1 £ 78


g/m3 Ta > 70°C

Note1: No condensation Note2: Ta = 70°C, RH = 42%

  • Driving for inverter(Ta = 25°C)
Parameter Symbol Min. Typ. Max. Unit Remarks

Combined load

Resistance RL 95 100 105 kW  



Stray capacity CL 5 pF



Input voltage

Power supply for inverter VDDB 10.8 12.0 13.2 V
BRTI signal VBI 0 2.5 V

BRTC signal

Low VBCL 0 0.4 V at inverter power OFF
High VBCH 2.5 VDDB V at inverter power ON
Input current Power supply for inverter IDDB 550 750 mA at maximum luminance, VDDB = 12.0V Note1


Output voltage

Power supply for LCD lamp VS 1,200 1,250 1,500 Vrms Starting voltage for lamp,

RL = ¥, CL = ¥


AM signal

Low VBA 0 0.5 V at normal
High VBA 4.5 5.0 5.5 V at malfunction
Output current LCD lamp IBL 4.5 5.0 5.5 mArms  


Oscillation frequency FO 50 55 60 kHz
Luminance control frequency for LCD lamp FL 220 250 280 Hz

Note1: The power supply lines (VDDB and GNDB) occurs large ripple voltage while luminance control of LCD lamps. There is the possibility that the ripple voltage produces acoustic noise and signal wave noise in audio circuit and so on. Put a capacitor (5,000 to 6,000mF) between the power source lines (VDDB and GNDB) to reduce the noise, if the noise occurred in the circuit.

  • Fuses


Fusing line Fuse Rating Unit Remark
Type Supplier





KOA Corporation

1.5 A Fusing current Note1
72 V

Note1: The power capacity should be more than the fusing current rating. If the power capacity is less than the criteria value, the fuse may not blow, and then nasty smell, smoking and so on may occur.

  • Detail of interface pins

CN1 socket: 53261-0890 (MOLEX Inc.)

Adaptable plug: 51021-0800 (MOLEX Inc.)

Pin No. Symbol Function Remarks
1 VDDB Power supply  

2 VDDB Power supply
3 GNDB Ground
4 GNDB Ground
5 BRTC Inverter ON/OFF signal ON: High or Open, OFF: Low
6 BRTI Input of luminance control by resistor / voltage control method Note1
7 GNDB Ground
8 AM Alert for malfunction signal 5.0V output at malfunction



CN2 socket: SM03 (4.0) B-BHS-TB (J.S.T. Mfg Co., Ltd.)

Adaptable plug: BHR-03VS-1 (J.S.T. Mfg Co., Ltd.)

CN1: Figure of socket

Pin No. Symbol Signal Remarks
1 VBLC Low voltage (Cold)  

2 VBLH High voltage (Hot)
3 VBLH High voltage (Hot)

CN2: Figure of socket