Datasheet

Detailed Description
The MAX9650/MAX9651 operational rail-to-rail
input/output amplifiers hold the VCOM voltage stable
while providing the ability to source and sink a high cur-
rent quickly (1.3A) into a capacitive load such as the
backplane of a TFT-LCD panel.
Thermal Shutdown
with Temperature Hysteresis
The MAX9650/MAX9651 are capable of high output
currents and feature thermal-shutdown protection with
temperature hysteresis. When the die temperature
reaches +170°C, the device shuts down. When the die
cools down by 15°C, the device turns on again. In a
TFT-LCD application, the duty cycle is very low. Even
with high values of voltage and current, the power dissi-
pation is low and the chip does not shut down.
High-Current VCOM Drive Op Amps
for TFT LCDs
Maxim Integrated 5
MAX9650/MAX9651
Pin Description
PIN
MAX9650
SOT23
µMAX-EP,
TDFN-EP
MAX9651
(µMAX-EP,
TDFN-EP)
NAME
FUNCTION
16 1
OUTA
VCOM Output A
24 4
GND
Ground
33 3
INA+
Positive Input A
42 2
INA-
Negative Input A
57 8V
DD
Positive-Supply Input. Bypass V
DD
to GND with a 0.1µF capacitor as close as
possible to the device.
—— 5
INB+
Positive Input B
—— 6
INB-
Negative Input B
—— 7
OUTB
VCOM Output B
— 1, 5, 8 —
N.C.
No Connection. Not internally connected.
—— —EP
Exposed Pad (μMAX and TDFN Only). EP is internally connected to GND. Connect EP
to GND.
IN_+
IN_-
GND
OUT_
V
DD
LCD VCOM LOAD
19V
SUPPLY
V
REF
*10μF and 0.1μF CAPACITORS AS CLOSE AS POSSIBLE TO THE PIN.
**(R
S
= R
GEN
) x C
LCD
x 6 < 2μs, WHERE R
GEN
= GENERATOR SOURCE IMPEDANCE.
MAX9650
*C2 = 0.1μF *C1 = 10μF
19V
SUPPLY
V
OUT_
C
LCD
=
0.1μF
R
S
=
2.2Ω
**0V TO 2.2V
AT 50kHz
Figure 1. Settling Time Test Circuit