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Standard ICs
Segment-type LCD driver
BU9729K
The BU9729K is a driver for segmented liquid crystal displays, which enables connection with a microcomputer
through a serial interface. 4-bit common output and an internal power supply circuit for LCD drive make it possible to
configure a low-cost display system.
1) Serial interface (8-bit length).
2) Display RAM: 72bits, internal (up to 72 segments
can be displayed).
3) Internal power supply circuit for liquid crystal drive.
4) Display duty: 1 / 4.
5) Low-voltage and low-current operation supported.
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Block diagram
Serial
Interface
Address
Counter
LCD Driver
Bias Circuit
Display Data RAM
(DD RAM)
LCD
Segment
Driver
18bits
LCD
Common
Driver
4bits
COM1
SEG1
COM2
COM3
COM4
SD
Command / Data
Register
Command
Decoder
Timing
Generator
Common
Counter
OSC1 OSC2
SCK
C / D
CS
VLCD
SEG2
SEG18
VC
VDD
VSS
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Features
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Applications
Movie projectors, car audio equipment, telephones