MAX8795AEVKIT+ Maxim Integrated Products, MAX8795AEVKIT+ Datasheet - Page 3

• Manufacturer Part Number: MAX8795AEVKIT+
• Description: Display Modules & Development Tools MAX8795A KIT MAX8795A KIT
• Manufacturer: Maxim Integrated Products

Specifications of MAX8795AEVKIT+

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

• 4.5V to 5.5VDC, 5A power supply
• Digital multimeters
The MAX8795A EV kit is fully assembled and tested.
Follow the steps below to verify board operation.
Caution: Do not turn on the power supply until all
connections are completed.
1) Connect the positive terminal of the DC power sup-
2) Verify that a shunt is placed across jumper JU1.
3) Turn on the power supply and verify that the step-
4) Verify that the positive linear-regulator output
5) Verify that the negative linear-regulator output
6) Verify that all buffer outputs (OUT1–OUT 5) are
The MAX8795A EV kit includes a high-performance
boost converter, two linear-regulator controllers, and
five high-current op amps optimized for complete TFT
LCD power requirements. The main supply step-up
switching circuit, which is powered from a +5V supply
and switches at 1.2MHz, provides a +14V output with at
least 500mA.
For regulated TFT gate-on supply, the EV kit employs a
positive single-stage charge pump and a linear
postregulator that provides +25V output (VPOS) and
supplies at least 20mA. For regulated TFT gate-off sup-
ply, the EV kit employs a negative single-stage charge
pump and a linear postregulator that provides -10V out-
put and supplies at least 50mA.
The EV kit also features five high-current op amps that
are ideal for driving the capacitive backplane of TFT
LCD panels. Each buffer is set to one-half of the main
supply output through external resistor-dividers.
ply to the VIN pad. Connect the negative terminal of
the DC power supply to the PGND pad.
Verify that there is no shunt placed across jumper
JU2.
up regulator output (VMAIN) is approximately +14V.
(VPOS) is approximately +25V.
(VNEG) is approximately -10V.
approximately +7V.
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Recommended Equipment
Detailed Description
Quick Start
Procedure
MAX8795A Evaluation Kit
The MAX8795A EV kit features a capacitive dummy
load of 1.5nF (C22) at the COM output pad to simulate
a panel load to test the switch matrix. Jumper JU1
selects and deselects the dummy load. Table 1 lists
jumper JU1 options.
Using a 2-pin jumper (JU2), the MAX8795A EV kit fea-
tures an option to control the high-voltage switches
between SRC, COM, and DRN. The switch between the
SRC and COM pins, and the switch between the COM
and DRN pins can also be controlled by an external
TTL logic source connected to the CTL pad. See Table
2 for switch states and refer to the Switch-Control Block
section in the MAX8795A IC data sheet for further infor-
mation about the high-voltage switches connected to
the COM pin.
Table 1. Jumper JU1 Functions
* Default position.
* Default position.
Table 2. Jumper JU2 Functions
Not installed*
Not installed*
Not installed
POSITION
POSITION
Installed
Installed
SHUNT
SHUNT
High-Voltage Switch Control Input (CTL)
Dummy Load for the High-Voltage
Connected to VIN
DUMMY LOAD
Connected to
GND through
Connected to
Connected to
Unconnected
external TTL
resistor R10
CTL PIN
source
(C22)
COM
Jumper Selection
Switch Output (COM)
(COM connected to DRN)
(COM connected to SRC)
COM connected to SRC
COM connected to DRN
EV KIT FUNCTION
Normal operation
TTL = logic-high
TTL = logic-low
COM OUTPUT
Testing mode
(panel load)
MAX8795A
(no panel)
(+25V)
(+14V)
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