AD8383

Rev. 0 | Page 9 of 16

APPLICATIONS

The V1 and V2 inputs in these systems are tied together and are

normally connected to VCOM, as shown in Figure 6.

V2

V1

VCOM

AD8383

Figure 6. Standard Connection Diagram

The transfer function of the AD8383 is shown in Figure 7 for

V2 = V1 = VCOM.

VBIAS = 1V

VCOM

VFS = 5V

VFS = 5V

RESERVED

CODE

RANGE

VBIAS = 1V

1023

820

Figure 7. Output Transfer Function for Standard Connection

EXTERNAL VBIAS GENERATION

In systems that require improved brightness resolution and

higher accuracy, the V1 and V2 inputs, connected to external

voltage references, provide the necessary VBIAS while allowing

the full code range to be used for gamma correction.

V1 sets the white drive voltage while INV = LOW and V2 sets

the white drive voltage while INV = HIGH. V1 and V2 are

defined as

V1 = VCOM – VBIAS

V2 = VCOM + VBIAS

To ensure a symmetrical ac driving voltage, the difference

between V2 and VCOM must be equal to the difference

between VCOM and V1.

(V2 – VCOM) = (VCOM – V1)

The circuit in Figure 8 ensures symmetry to within 1 mV with a

minimum component count. Bypass capacitors are not shown

for clarity.

The transfer function and the input symmetry error of the

AD8383 are shown in Figure 9 when the circuit of Figure 8 is

used to generate VBIAS.

AVCC = 15.5V

VZ = 5.1V

DVCC = 3.3V

VCOM = 7V

R1 = 6k

Ω

R2 = 1k

Ω

V2 = 8V

V1 = 6V

V2

V1

AD8383

AD8132

6

3

2

1

8

V–

V+

VCOM

–IN

+IN

5

4

Figure 8. High Accuracy Reference Circuit

VBIAS = 1V

VCOM

V2

V1

VFS = 4V

VFS = 4V

VBIAS = 1V

THE AD8383, IN THE APPLICATIONS

CIRCUIT SHOWN, TYPICALLY PRODUCES

A SYMMETRICAL OUTPUT AT 85°C WHEN

ITS SUPPLY, (V+) – (V–), IS AT 7.2V.

1023

Figure 9. Transfer Function for High Accuracy Reference Applications

5.7

6.2

6.7

7.2

7.7

8.2

8.7

9.2

9.7

10.2

10.7

–8.75

–6.25

–3.75

1.25

3.75

6.25

7.50

8.75

–1.25

–7.50

–5.00

0.00

2.50

5.00

–2.50

TYPICAL ASYMMETRY AT THE OUTPUTS OF THE

AD8383 VERSUS ITS POWER SUPPLY FOR THE

APPLICATION CIRCUIT

Figure 10. Accuracy for High Accuracy Reference Applications