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

Page 16

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

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Contents USER’S Manual AN.No.G1216B1N000-3D0ECopyright 1993 by Seiko Instruments Inc Contents General +80 Temperature Storage Symbol Conditions Min Typ Max Unit Input HighPower supply voltage VoltageMin Typ Max Unit Remark 25 C Vopr=13.0 Viewing angle∅ = 25 C Vopr=13.0 Contrast 25 C Vopr=13.0AN.No.G1216B1N000-3D0E Definition of response time −20 To +70 Storage temp. rangeLeda Number of LEDChips=20 LedcDB0 DB1DB2 DB3CS2 CS1 Circuit ConfigurationV c, V d, V f CS R/W FRMMSB LSBBusy Page COM1 COM2COM3 COM4Operational Amplifier Bias R2= 9 4 R1= 5 R1 MPU Operating InstructionsCS1 CS2 450 140To DB7 Test point RL = 2.4 k = 11 kReset time Rise time 200Detailed explanation Display ON/OFF Code FunctionD/I AN.No.G1216B1N000-3D0E Display start line Code DB7 DB0Display start line=0 Display start line=1 Display start line =2 Display start line=3Display Data RAM Address Configuration AN.No.G1216B1N000-3D0E Address page set CodeReset Voltage V opr 13.5 13.0 12.5 11.5 10.5 =10 k Ω=1.2 k Ω Variable resistor=Input voltage power voltageV =LED forward voltage=Allowable LED forward current a Leda LedcMPU Connection Diagram Z80 PIOD0 to D7 A0 to A7 DB0 to DB7 A0 to A15 Decoder Iorq RST CS1Precautions 9, 11, 12, 17, 18, 19 11, 12, 1710, 16, 17 LC drive voltageSeiko Instruments Inc
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