Quick Start

Recommended Equipment

•

12V, 100mA power supply (VSOURCE)

•

3.3V power supply (VDD)

•

Electronic load capable of sinking 100mA

•

Digital voltmeter (DVM)

Procedure

The MAX9922 EV kit is fully assembled and tested.

Follow the steps below to verify board operation.

Caution: Do not turn on power supplies until all con-

nections are completed.

1) Verify that all jumpers (JU1, JU2, and JU3) are in their

default positions, as shown in Tables 1, 2, and 3.

2) Set the input power supply to 12V. Connect the

ground of the power supply to the PGND pad, and

connect the positive terminal to the VSOURCE pad.

3) Set the VDD power supply to 3.3V. Connect the

ground of the VDD supply to the GND pad and

connect the positive terminal to the VDD pad.

4) Set the electronic load to sink 100mA.

5) Connect the load’s ground to the GND pad.

Connect the electronic load’s positive terminal to

the LOAD pad.

6) Connect the DVM across the VOUT pad and the

GND pad.

7) Turn on the 3.3V power supply.

8) Turn on the 12V power supply.

Detailed Description of Hardware

The MAX9922 EV kit is a current-sense amplifier that

measures the load current and provides an analog volt-

age output. The EV kit comes assembled with the

MAX9922 IC, which allows adjustable gain with a pair

of external resistors (R2 and R3) between OUT, FB, and

REF. The EV kit is configured for bidirectional current

lowing equation:

Shutdown Input Control

The MAX9922 EV kit features 2-pin jumper JU1 to con-

trol the logic shutdown input. For normal operation,

remove the shunt from jumper JU1 to drive

SHDN high.

To place the device in shutdown mode, drive

SHDN low

by placing a shunt across the JU1 pins. Table 1 sum-

marizes jumper JU1’s function.

VR

R

R

I

OUT

SENSE

SENSE

=×

+

⎛

⎝⎜

⎞

⎠⎟

×

1

2

3

VR

R

R

IV

OUT

SENSE

SENSE

REF

=×

+

⎛

⎝⎜

⎞

⎠⎟

×+

1

2

3

VR

R

R

IV

OUT

SENSE

SENSE

REF

=×

+

⎛

⎝⎜

⎞

⎠⎟

×+

1

2

3

MAX9922 Evaluation Kit

2

_______________________________________________________________________________________

SUPPLIER

PHONE

WEBSITE

IRC, Inc.

361-992-7900

www.irctt.com

Keystone Electronics Corp.

209-796-2032

www.keyelco.com

Murata Electronics North America, Inc.

770-436-1300

www.murata-northamerica.com

TDK Corp.

847-803-6100

www.component.tdk.com

Component Suppliers

Note: Indicate that you are using the MAX9922 when contacting these component suppliers.

Table 1. Jumper JU1 Function (

SHDN)

SHUNT

POSITION

SHDN PIN

MODE

Installed

Connected to GND

Shutdown mode

Not installed*

Connected to VDD

through pullup resistor R4

Normal operation

*

Default position.