UPD16680 datasheet(12/44 Pages) NEC

12 / 44 page

Data Sheet S12694EJ2V0DS00

µµµµPD16680

5.2.2 To use internal driving circuit and D/A converter ( VEXT = L , DACHA = H )

To use D/A converter, it is possible to adjust reference voltage VREF inputted to AMPIN(+) pin for LCD driving by

command.

To set 6-bit data to D/A converter register, reference voltage VREF is choose one level from 64 level in 1/2 VDD to VDD.

The formula of VLC1 is as same written in Equation 5-1.

Figure 5-3 Using internal power supply select and D/A converter

VDD

to Internal driving circuit

D/A

Converter

AMPIN(-)

AMPout

VLC1

−

Rth

AMPIN(+)

DACHA

Open

VREF

5.2.3 To use external driving circuit ( VEXT = H )

When external voltage supply circuit for LCD driving is chosen, operational amplifier incorporated IC is off.

Therefore, it is impossible to use operational amplifier for LCD driving and D/A converter function. LCD driving

voltage is adjust by the voltage inputted to VLCD and VLC1 pins directly.

Remarks 1. Set VLCD

≥ VLC1.

2. DACHA , AMPIN(+), AMPIN(-) are CMOS input. Set H level or L level.

3. Set AMPOUT pin "open".

UPD16680 데이터시트(PDF) 12 Page - NEC