MAX1512 Maxim Integrated Products, MAX1512 Datasheet - Page 7

• Manufacturer Part Number: MAX1512
• Description: EEPROM-Programmable TFT VCOM Calibrator
• Manufacturer: Maxim Integrated Products

Figure 2. Simplified Functional Diagram
The external resistive voltage-divider sets the maximum
value of the VCOM adjustment range. R
full-scale sink current, I
mum value of the VCOM adjustment range. Large R
values increase resolution but decrease the VCOM
adjustment range. Calculate R1, R2, and R
the following procedure:
1) Choose the maximum VCOM level (V
2) Calculate the R1 / R2 ratio:
3) Calculate the R1 / R
mum VCOM level (V
voltage (V
EEPROM-Programmable TFT VCOM Calibrator
R
AVDD
SET
R
CTL
1
_______________________________________________________________________________________
).
R
≅
R
2
1
CE
CTL
(
Adjustment Range (R
OUT
V
SET
≅
MAX
MIN
V
INTERFACE
V
CONTROL
V
DD
, which determines the mini-
V
ratio:
AVDD
MAX
V
MAX
DD
-V
), and the AVDD supply
MIN
Setting the VCOM
7
-
1
7
)
×
20
MAX
DAC
SET
EEPROM
), the mini-
SET
sets the
R
19R
using
SET
SET
)
MAX1512
4) Choose R
5) The resulting resolution is:
A complete design example is given below:
1) V
4) If R
5) Resolution = 15.75mV
2
3
)
)
Electrical Characteristics section and calculate the
values for R1 and R2.
R
R
200kΩ
R
MAX
1
2
R
SET
1
SET
≅
AVDD
= 5V, V
GND
=
OUT
10
SET
5
= 24.9kΩ, then R1 = 200kΩ and R2 =
20
Re solution
SET
- 1
AVDD
×
MIN
according to the limits shown in the
=
R1
R2
R
SET
(
1
5 3
= 3V, V
5
-
)
=
=
8
(
AVDD
V
MAX
127
-V
= 10V
VCOM
MIN
)
7