Seiko Instruments G1216B1N000 Operational Amplifier Bias R2= 9 4 R1= 5 R1, Bias Voltage Generator

AN.No.G1216B1N000-3D0E

￿Y-address counter

This counter sets the address by instruction and is automatically advanced by the read/write operation. Counting is performed by looping the values 0 to 63.

2.3Common driver (HD61203)

The common driver is a 64 drive output CMOS IC. Incorporating an oscillation circuit, this driver generates the common signal and timing signals (LC AC drive control, and one-frame timing signal) necessary for the LC display, and controls the display by supplying the timing signals to the segment drivers.

2.4Bias voltage generator

Six levels of standard voltage Va to Vf are applied to the drivers as a bias voltage. This voltage is generated by resistance division of Vopr and driven by a voltage follower through an operational amplifier.

VDD

R1

R1

Vopr R2

R1

R1

VLC

		Va
		C
+		Vb
		C
+￿		Vc
		C
+￿		Vd
		C
+	Operational	Ve
		C
	Amplifier
		Vf

1 / 9 bias: R2= (9 ￿4) R1= 5 R1

Figure 7 Bias Voltage Generator

- 13 -