Figure 9 shows a four wire remote display that takes advan-

tage of the device’s serial input to move many bits of display

information on a few wires.

USING AN EXTERNAL CLOCK

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. In

Figure 8, a flip-flop is used to assure

a 50% duty cycle. The oscillator input is grounded to prevent

oscillation and reduce current consumptions in the chips.

The oscillator is not used.

Using an external clock allows synchronizing the display

drive with AC power, internal clocks, or DVM integration time

to reduce interference from the display.

Figure 10 is a general block diagram that shows how the

device’s serial input can be used to advantage in an analog

display. The analog voltage input is compared with a stair-

case voltage generated by a counter and a digital-to-analog

00613707

*The minimum recommended value for R for the oscillator input is 9 k

frequency between 30 Hz and 150 Hz.

FIGURE 7. Parallel Backplane Outputs

00613708

FIGURE 8. External Backplane Clock

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