
Novatek Microelectronics
General Description
The NT7502 is a single-chip LCD driver for dot-matrix liquid crystal displays which is directly connectable to a microcomputer bus. It accepts 8-bit serial or parallel display data directly sent from a microcomputer and stores it in an on-chip display RAM. It generates a LCD drive signal independent of the microprocessor clock.
The set of the on-chip display RAM of 65 X 132 bits and a one-to-one correspondence between LCD panel pixel dots and on-chip RAM bits permit implementation of displays with a high degree of freedom.
The NT7502 contains 65 common output circuits and 132 segment output circuits, so that a single chip of NT7502 can make 65 X 132, 55 X 132, 49 X 132 and 33 X 132 dot displays with pad option (DUTY1, DUTY0).
No external operation clock is required for RAM read/write operations. Accordingly, this driver can be operated with a minimum current consumption and its onboard low-current-consumption liquid crystal power supply can implement a high-performance handy display system with minimum current consumption and the smallest LSI configuration.
FEATUREs
■ Direct RAM data display using the display RAM. When RAM data bit is 0, it is not displayed. When RAM data bit is 1, it is displayed. (At normal display)
■ RAM capacity: 65 X 132 = 8580 bits
■ Many command functions: Read/Write Display Data.
Display ON/OFF. Normal/Reverse Display. Page Address Set. Set Display Start Line. Set LCD Bias, Electronic contrast Controls, V0 voltage regulation internal resistor ratio set, Read Modify Write, Select Segment Driver Direction, Power Save
■ High-speed 8-bit microprocessor interface allowing direct connection to both the 8080 and 6800
■ Serial interface
■ Power supply voltage: 2.4 - 3.5V
■ Maximum 12V LCD driving output voltage
■ 2X / 3X / 4X on chip DC-DC converter
■ Voltage regulator
■ Voltage follower
■ On-chip oscillator