TI MM5453VX/NOPB

The MM5452 is a monolithic integrated circuit utilizing CMOS metal gate, low threshold enhancement mode devices. It is available in a 40-pin PDIP package. The chip can drive up to 32 segments of LCD and can be paralleled to increase this number. The chip is capable of driving a 4% -digit 7-segment display with minimal interface between the display and the data source. The MM5452 stores display data in latches after it is clocked in, and holds the data until new display data is received. The MM5452 is specifically designed to operate 4% -digit 7-segment displays with minimal interface with the display and the data source. Serial data transfer from the data source to the display driver is accomplished with 2 signals, serial data and clock. Since the MM5452 does not contain a character generator, the formatting of the segment information must be done prior to inputting the data to the MM5452. Using a format of a leading “1” followed by the 32 data bits allows data transfer without an additional load signal. The 32 data bits are latched after the 36th clock is complete, thus providing non-multiplexed, direct drive to the display. Outputs change only if the serial data bits differ from the previous time. For the MM5452 a DATA ENABLE is used instead of the 33rd output. If the DATA ENABLE signal is not required, the 33rd output can be brought out. This is the MM5453 device. The MM5452/MM5453 LCD Drivers can be used with an externally supplied clock, provided it has a duty cycle of 50%. Deviations from a 50% duty cycle result in an offset voltage on the LCD. Using an external clock allows synchronizing the display drive with AC power, internal clocks, or DVM integration time to reduce interference from the display.

• Serial Data Input
• No Load Signal Required
• DATA ENABLE (MM5452)
• Wide Power Supply Operation
• TTL Compatibility
• 32 or 33 Outputs
• Alphanumeric and Bar Graph Capability
• Cascaded Operation Capability

• COPS or Microprocessor Displays
• Industrial Control Indicator
• Digital Clock, Thermometer, Counter, Voltmeter
• Instrumentation Readouts
• Remote Displays