MAX1512 Datasheet, PDF (9/12 Pages) Maxim Integrated Products – EEPROM-Programmable TFT VCOM Calibrator

EEPROM-Programmable TFT VCOM Calibrator
V_DD
PROGRAMMING
CIRCUIT
CE
R_CE
MAX1512
CTL
GND
Figure 5. Optional Circuit to Drive CE
The programming circuit in Figure 5 drives CE high to
enable the CTL input when it is connected. When the
programming circuit is not connected, CE is pulled low
through resistor R_CE, which disables the CTL input. The
CTL input is relatively immune to noise and brief volt-
age transients. It can be safely left continuously
enabled if higher supply current is acceptable.
VCOM Adjustment (CTL)
Pulse CTL low for more than 200µs to increment the DAC
setting, which increases the OUT sink current and lowers
the VCOM level by 1 least-significant bit (LSB) (Figure 6).
Similarly, pulse CTL high for more than 200µs to decre-
ment the DAC setting, which decreases the OUT sink cur-
rent and increases the VCOM level by 1 LSB.
CTL HIGH
CTL
V_DD/2
CTL LOW
CE / V_DD
>1ms
>200µs
>200µs
>200µs >10µs >200µs <20µs
<20µs
FIRST
COUNT
IGNORED
CTL
ENABLED
SHORT
COUNTS
IGNORED
VCOM UP
VCOM DOWN
DAC SETTING
UNDEFINED
64
65
64
63
VCOM
Figure 6. VCOM Adjustment
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