The MAX5422 main circuit area consists of the

MAX5422 IC U1, decoupling capacitors C25 and C26,

jumpers JU1, JU2, and JU3, header J2, and PCB pads

H, W, L, VCC, and GND. The MAX5422 main circuit

PCB section is less than 1.2in x 1.1in and can be sepa-

rated from the EV kit using the cutout slots, allowing the

MAX5422 to be conveniently attached to a user appli-

cation. After separation, the two parts of the EV kit can

be reconnected using a short cable. A short ribbon

cable of about 3in is recommended to reconnect the

MAX5422 EV kit. A Samtec IDSS-06-D-3.00 ribbon

cable can be used to connect header J1 odd pins to

header J2 odd pins.

Jumper Selection

Using an External DC Power Supply

The MAX5422 EV kit can be powered by an external

2.7V to 5.25V DC power supply. The EV kit can still be

programmed through the USB interface using the soft-

ware GUI. To connect the EV kit to an external power

supply, disconnect the USB cable and install a shunt

on pins 2-3 of jumper JU1. Turn off the power supply

and connect the power-supply ground terminal to the

EV kit GND pad, and the power-supply positive terminal

to the VCC pad. Table 2 lists the various options for

powering the MAX5422 EV kit.

SPI Clock and Data/Chip Select Inputs

The MAX5422 features a clock and data/chip select input

pins for SPI-compatible communication to control the

MAX5422 wiper position and transfer data between volatile

and nonvolatile memories. The clock and data/chip select

pins can be driven by the on-board USB interface circuit

or the PCB header (J2), along with a user-supplied exter-

nal SPI-compatible controller. An external SPI-compatible

controller can be connected to the SCLK (J2-6), DIN (J2-

8),

CS (J2-10), and GND (J2-12) on header J2 to commu-

nicate with the MAX5422 IC. When using an external SPI-

compatible controller, disconnect the on-board USB inter-

face circuit by removing all the shunts from header J1.

Headers J1 and J2 select the SPI serial-interface signal-

control sources for the MAX5422 IC. Table 3 lists the

various options for configuring SPI input signal controls.

MAX5422 Evaluation Kit

8

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Table 2. JU1 Jumper Functions (VDD)

SHUNT

POSITION

TO

EV KIT POWERED

FROM

1-2*

3.3V

USB interface circuit

2-3

External power supply

(2.7V to 5.25V)

Open

Not connected

Do not use (EV kit is

not powered)

*

Default position.

Table 3. J1, J2 Header Functions (+3.3V, VDD, SCLK, DIN,

CS, GND)

HEADER POSITION

SHUNT POSITION

EV KIT FUNCTION

Installed*

Connects +3.3V from USB interface to MAX5422

J1 (1-2)

Not installed

Disconnect +3.3V from USB interface to MAX5422

Installed*

Connects VDD from MAX5422 to USB interface

J1 (3-4)

Not installed

Disconnect VDD from MAX5422 to USB interface

Installed*

Connects SCLK from USB interface to MAX5422

J1 (5-6)

Not installed

Disconnect SCLK from USB interface to MAX5422

Installed*

Connects DIN from USB interface to MAX5422

J1 (7-8)

Not installed

Disconnect DIN from USB interface to MAX5422

Installed*

Connects

CS from USB interface to MAX5422

J1 (9-10)

Not installed

Disconnect

CS from USB interface to MAX5422

J1 (11-12)

Not installed

Shunt not required

J2 (1-2)

J2 (3-4)

J2 (5-6)

J2 (7-8)

J2 (9-10)

Not installed

Do not install shunts on these pins. Shunts will short the power and signal

lines to ground.

J2 (11-12)

Not installed

Shunt not required

*

Default position.