MAX17108 Evaluation Kit
Evluates:MAX7108
8) Connect the +6V to +20V power-supply positive
terminal to the AVDD PCB pad. Connect the
power-supply ground terminal to the PGND pad.
configuration of jumper JU1. Jumpers JU2–JU11 are provid-
ed to connect RC loads at the MAX17108Y 1–Y10 outputs.
The MAX17108 VCOM amplifier output is configured as
a unity-gain buffer and is set to half the voltage applied
at the AVDD PCB pad, using resistors R1 and R2. To
reconfigure VCOM to other voltages, replace resistor
R1. The VCOM output can be monitored using the EV
kit VCOM and GND PCB pads.
9) Connect the +12V to +38V power-supply positive
terminal to the GON1 PCB pad. Connect the
power-supply ground terminal to the PGND pad.
10) Enable the GOFF negative power supply and set it
to -12V.
11) Enable the AVDD positive power supply and set it
to +12V.
Power Supplies Configuration
The MAX17108EV kit requires two positive power supplies
and one negative power supply for proper evaluation of
the EV kit. AVDD requires a +6V to +20V power supply
that provides up to 250mA of current. GON1 and GON2
each require a +12V to +38V power supply providing up
to 500mA of current. GOFF requires a -12V to -4V power
supply that provides up to 500mA of current.
12) Enable the GON1 positive power supply and set it
to +20V.
13) Adjust potentiometer R56 until the voltmeter at
LDO_OUT reads +3.3V.
14) Verify that the output of the high-speed op amp
(VCOM) is +6V.
Jumper JU1 configures the input power source for
GON2. Install a shunt across pins 1-2 of jumper JU1 to
select GON1 as the input power source for GON2.
Install a shunt across pins 2-3 of jumper JU1 to apply
an external power source at the GON2 and PGND PCB
pads. Buffers Y7 and Y8 output the voltage applied at
the GON2 PCB pad. See Table 1 for proper jumper JU1
configuration.
15) Verify that test points TP1–TP10 outputs are +20V.
Detailed Description of Hardware
The MAX17108 evaluation kit (EV kit) is a fully assem-
bled and tested surface-mount PCB that evaluates the
MAX17108 10-channel, high-voltage level-shifting scan
drivers for thin-film transistor (TFT) liquid-crystal display
(LCD) applications. The EV kit requires two positive
power supplies and one negative power supply. AVDD
requires a +6V to +20V power supply that provides up
to 250mA of current. A +12V to +38V power supply that
provides up to 1A of current is required when powering
both the GON1 and GON2 inputs. The GON1 and
GON2 inputs can also be powered using separate
power supplies that provide up to 500mA each of cur-
rent. GOFF requires a -12V to -4V power supply that
provides up to 500mA of current.
Table 1. GON2 Power Source Selection
(JU1)
SHUNT
GON2 IC PIN
POSITION
1-2
Connected to GON1
Connected to external power source at GON2
and PGND PCB pads
2-3
The MAX17108 logic level to high-voltage level-shifting
scan drivers can buffer 10 logic inputs (A1–A10) and
shift them to a desired level (Y1–Y10) for driving TFT-
LCD row logic. GON1 supplies the high-voltage levels
at the MAX17108 buffers Y1–Y6, Y9, and Y10 when its
respective input is a logic-high. GON2 supplies the
high-voltage levels at the MAX17108 buffers Y7 and Y8
when its respective input is a logic-high. GOFF supplies
the low-voltage level at all of the scan-driver outputs
when their input is a logic-low. DIP switch Sꢁ1 is used
to set a DC logic-high level at A1–A10 inputs for testing
purposes, by using a high-voltage input LDO regulator
U2 (MAX6771) and potentiometer R56.
Additional surface-mount 1206 PCB pads are provided
for adding additional bulk capacitance at C1, C88, C89,
and C90 when interfacing long wires to the EV kit’s
AVDD, GON1, GON2, and GOFF power-supply inputs.
Output Load Connection
The MAX17108 EV kit provides resistor/capacitor loads
for each output channel to mimic TFT-LCD panel load
models for easy evaluation of the EV kit. Install shunts
across jumpers JU2–JU11 to connect the RC loads to
the MAX17108 scan-driver outputs. Place a scope
probe across the shunts installed at jumpers
JU2–JU11 and PGND for proper evaluation of the
MAX17108 buffers (Y1–Y10), when applying a square-
wave signal at the SIGNAL_IN PCB pad. Test points
TP1–TP10 can be used to monitor the loaded buffer out-
puts when applying static DC voltages at the A_ inputs.
Jumper JU1 is provided for evaluation of the MAX17108
EV kit when utilizing one power source for the
MAX17108 GON1 and GON2 power inputs. See the
Power Supplies Configuration section for proper
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