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Rainbow Electronics MAX1495 User Manual

Page 15

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MAX1491/MAX1493/MAX1495

3.5- and 4.5-Digit, Single-Chip

ADCs with LCD Drivers

______________________________________________________________________________________

15

φ1

φ2

φ3

φ1'

φ2'

φ3'

V

LCD

-V

LCD

0

V

RMS

= V

LCD

/ 3 (OFF)

V

LCD

-V

LCD

0

V

RMS

= V

LCD

/ 3 (OFF)

V

LCD

-V

LCD

0

V

RMS

= 1.92V

LCD

/ 3 (ON)

V

LCD

-V

LCD

0

V

RMS

= 1.92V

LCD

/ 3 (ON)

ALL
OFF

φ1, φ2, φ3 - - BP HIGH WITH RESPECT TO SEGMENT (BP+ TIME)

φ1', φ2', φ3' - - BP LOW WITH RESPECT TO SEGMENT (BP- TIME)
BP1 ACTIVE DURING

φ1 AND φ1'

BP2 ACTIVE DURING

φ2 AND φ2'

BP3 ACTIVE DURING

φ3 AND φ3'

V

G

= V

Y

- V

BP2

(DIFFERENCE BETWEEN SEGMENT LINE Y AND BP2 VOLTAGE)

VOLTAGE CONTRAST RATIO = V

RMS

ON / V

RMSOFF

= 1.922

a ON

g, d OFF

a, g ON

d OFF

ALL

ON

Figure 11. Voltage Waveforms on the g Segment