hd66789 Renesas Electronics Corporation., hd66789 Datasheet - Page 115

• Manufacturer Part Number: hd66789
• Description: 528-channel, One-chip Driver For Amorphous Tft Panels With 262,144-color Display Ram, Power Supply Circuit, And Gate Circuit
• Manufacturer: Renesas Electronics Corporation.

HD66789
J-Correction Registers
Register
Groups
Gradient
adjustment
Amplitude
adjustment
Fine adjustment
Ladder resistors and 8-to-1 selector
Block configuration
The block diagram of page 112 consists of two ladder resistors including variable resistors, and 8-to-1
selectors which select the voltage generated by the ladder resistors to output a reference voltage for the
grayscale voltage. The variable resistors and the 8-to-1 selectors are controlled by the J correction registers.
Pins that are connected to a variable resistor are provided to compensate the variation among the panels.
Variable resistor
There are three kinds of variable resistors for the gradient adjustment (VRHP(N)/VRLP(N)), the amplitude
adjustment (1) (VRP(N)0), and the amplitude adjustment (2) (VRP(N)1). The resistance is determined by
the gradient adjustment and amplitude adjustment registers as is shown below.
Gradient adjustment
Contents of Register
PRP(N) 0/1[2:0]
Rev.0.12, May 09 2003, page 115 of 156
000
001
010
011
100
101
110
111
Positive
Polarity
PRP0 2 to 0
PRP1 2 to 0
VRP0 3 to 0
VRP1 4 to 0
PKP0 2 to 0
PKP1 2 to 0
PKP2 2 to 0
PKP3 2 to 0
PKP4 2 to 0
PKP5 2 to 0
Resistance
VRHP(N)
VRLP(N)
12R
16R
20R
24R
28R
0R
4R
8R
Negative
Polarity
PRN0 2 to 0
PRN1 2 to 0
VRN0 3 to 0
VRN1 4 to 0
PKN0 2 to 0
PKN1 2 to 0
PKN2 2 to 0
PKN3 2 to 0
PKN4 2 to 0
PKN5 2 to 0
Amplitude adjustment (1)
Contents of Register
VRP(N)0[3:0]
0000
0001
0010
1101
1111
1111
x
x
x
x
Description
Variable resistor VRHP (N)
Variable resistor VRLP (N)
Variable resistor VRP (N)0
Variable resistor VRP (N)1
8-to-1 selector (voltage level of grayscale 1)
8-to-1 selector (voltage level of grayscale 8)
8-to-1 selector (voltage level of grayscale 20)
8-to-1 selector (voltage level of grayscale 43)
8-to-1 selector (voltage level of grayscale 55)
8-to-1 selector (voltage level of grayscale 62)
Resistance
VRP(N)0
26R
28R
30R
0R
2R
4R
x
x
x
x
Amplitude adjustment (2)
Contents of Register
VRP(N)1[4:0]
00000
00001
00010
11101
11110
11111
Preliminary
x
x
x
x
Resistance
VRP(N)1
29R
30R
31R
0R
1R
2R
x
x
x
x