Detailed Description of Hardware

The MAX17088 EV kit contains a step-up switching reg-

ulator, positive two-stage charge pump, negative two-

stage charge pump, digitally adjustable VCOM calibra-

tion device with nonvolatile memory, SMBus-compati-

ble interface, high-speed operational amplifier (op

amp), and high-voltage level-shifting scan driver for

TFT-LCD applications. The EV kit operates from a sin-

gle DC power supply between +1.8V and +6V that pro-

vides at least 2A.

As configured, the step-up switching regulator (MAIN)

generates a +8V output and provides at least 200mA

from a +1.8V input. It also provides at least 300mA from

a +2.2V input and 600mA from a +4.5V input. The step-

up switching-regulator output voltage can be adjusted

up to +18V with different feedback resistors (see the

Output-Voltage Selection section).

The GON consists of two positive charge-pump stages

to generate approximately +21V and provides greater

than 20mA. The GOFF consists of two negative charge-

pump stages to generate approximately -13V and pro-

vides greater than 20mA. Loading GON and GOFF

reduces the available MAIN current proportionally.

The op-amp output (VCOM) is SMBus programmable

and is configured for an output-voltage range of +2.4V

to +4V. VCOM can source or sink peak current up to

150mA. The output-voltage range can be reconfigured

to other voltages with voltage-divider resistors R6 and

R7. Refer to the

Setting the VCOM Adjustment Range

section in the MAX17088 IC data sheet for more details.

The MAX17088 includes a 3-channel, high-voltage

level-shifting driver for driving row-driver functions on

the panel glass. CKV, CKVB, and STVP pads are the

outputs of the driver. The outputs swing between GON

and GOFF according to the input logic levels on the

STV, CPV, and OE pads and the IC’s internal logic.

Refer to the

High-Voltage Level-Shifting Scan Driver

section in the MAX17088 IC data sheet for more details.

Jumper Selection (JU1, JU2)

The MAX17088 EV kit incorporates jumper JU1 to

enable/disable the IC outputs and jumper JU2 to

enable/disable write protection. When write protection

is enabled, all SMBus commands are ignored by the

device. This prevents device detection and changing of

the VCOM calibrator settings. See Table 1 for jumper

JU1 functions and Table 2 for jumper JU2 functions.

MAX17088 Evaluation Kit/

Evaluation System

4

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Figure 1. MAX17088 EV Kit Software Main Window

Table 1. Jumper JU1 Functions

SHUNT

POSITION

SHDN PIN

EV KIT OUTPUTS

Installed*

SHDN connected to PIN

Outputs enabled

(MAIN = +8V)

Not installed

SHDN connected to GND

through R5

Outputs disabled

(MAIN

≈ PIN)

*

Default position.