MAX1492 Maxim, MAX1492 Datasheet - Page 13

• Manufacturer Part Number: MAX1492
• Description: 3.5- and 4.5-Digit / Single-Chip ADCs with LCD Drivers
• Manufacturer: Maxim

Figure 6. Backplane Connection for the MAX1492 (3.5 Digits)
Figure 7. Segment Connection for the MAX1492 (3.5 Digits)
thus the contrast of the segment. The RMS OFF voltage
is always V
always 1.92V
ratio of RMS ON to RMS OFF voltage is fixed at 1.92 for
a triplexed LCD.
Figure 12 illustrates contrast vs. applied RMS voltage
with a V
the RMS OFF voltage is 1.1V. The OFF segment has a
LCD
LCD
of 3.1V. The RMS ON voltage is 2.1V, and
LCD
/ 3, whereas the RMS ON voltage is
/ 3. This is illustrated in Figure 11. The
______________________________________________________________________________________
SEG9: F3, E3, DP3
3.5- and 4.5-Digit, Single-Chip ADCs
SEG8: A3, G3, D3
HOLD
SEG10: PEAK, HOLD, BC4
HOLD
PEAK
PEAK
SEG7: B3, C3, MINUS
SEG6: F2, E2, DP2
LOW BATT
contrast of less than 5%, while the ON segments have
greater than 85% contrast.
If ghosting is present on the LCD, the RMS OFF voltage
is too high. Choose an LCD with a higher RMS OFF
voltage. Alternatively, lower the supply or apply a volt-
age on V
Figures 9 and 10 show the voltage on the LCD’s BP_
inputs and the segment inputs during normal operation.
LOW BATT
SEG5: A2, G2, D2
DISP
SEG4: A2, G2, LOWBATT
SEG3: F1, E1, DP1
to lower the RMS OFF voltage.
with LCD Drivers
SEG2: A1, G1, D1
SEG1: B1, C1, N.C.
BP1
BP2
BP3
ANNUNCIATOR
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