UPD16633B datasheet(6/20 Pages) NEC

6 / 20 page

µµµµPD16633B

5. RELATIONSHIP BETWEEN INPUT DATA AND OUTPUT VOLTAGE VALUE

This product incorporates a 6-bit D/A converter whose odd output pins and even output pins output respectively

gray scale voltages of differing polarity with respect to the LCD’s counter electrode (common electrode) voltage. The

D/A converter consists of ladder resistors and switches. The ladder resistors r0 to r62 are so designed that the ratios

between the LCD panel’s

γ-corrected voltages and V0’ to V63’ and V0” to V63” are roughly equal; and their respective

resistance values are as shown on page 9. Among the 5-by-2

γ-corrected voltages, input gray scale voltages of the

same polarity with respect to the common voltage, for the respective five

γ-corrected voltages of V0 to V4 and V5 to

V9.

Figure 1 shows the relationship between the driving voltages such as liquid-crystal driving voltages VDD2 and VSS2,

common electrode potential VCOM, and

γ-corrected voltages V0 to V9 and the input data. Be sure to maintain the

voltage relationships of VDD2 > V0 > V1 > V2 > V3 > V4 > V5 > V6 > V7 > V8 > V9 > VSS2.

Figures 2-1 and 2-2 show the relationship between the input data and the output data.

Table 1 shows the

resistance values of the resistor strings.

This driver IC is designed for single-sided mounting. Therefore, please do not use it for

γ-corrected power supply

level inversion in double-sided mounting. Because the current flowing through ladder resistors r0 to r62 is small, its

use for double-sided mounting impairs the IC’s stable operation when the level of the

γ-corrected power supply

terminal is inverted thus causing display failures.

Figure 1. Relationship Between Input Data and Output Voltage

Input data (HEX)

(POL2 = L)

40 (Invalid)

0.1 V

VSS2

0.1 V

VDD2

VCOM

UPD16633B Datasheet(PDF) 6 Page - NEC