MAX9922EVKIT [MAXIM]

Fully Assembled and Tested;


型号：	MAX9922EVKIT
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	Fully Assembled and Tested
文件：	总7页 (文件大小：132K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

19-4487; Rev 0; 3/09

MAX9922 Evaluation Kit

Evluates:/MAX923

General Description

Features

The MAX9922 evaluation kit (EV kit) is a fully assembled

and tested PCB used to evaluate the MAX9922 and

MAX9923 ultra-precision, high-side current-sense

o Bidirectional or Unidirectional Current Sensing

o Shutdown Logic Input Control

amplifiers. An ultra-low offset voltage (V ) of 10µV

o Multiple Gains Available

Adjustable (MAX9922)

25V/V (MAX9923T)

(max) allows accurate measurement of currents at both

extremes of sense voltages (V

), from 10mV to

SENSE

100mV. The EV kit has a 1.9V to 28V input common-

mode sense voltage range that is independent of the

100V/V (MAX9923H)

250V/V (MAX9923F)

2.85V to 5.5V V

supply.

o 2.85V to 5.5V Supply Range (V

)

The MAX9922 EV kit comes assembled with the

MAX9922 IC with adjustable gain, but can also evaluate

the MAX9923 ICs with fixed gains of 25V/V

(MAX9923T), 100V/V (MAX9923H), and 250V/V

(MAX9923F). The MAX9922/MAX9923 are capable of

both unidirectional and bidirectional operation.

o 1.9V to 28V Input Common-Mode Range

Independent of V

o Lead(Pb)-Free and RoHS Compliant

o Fully Assembled and Tested

Ordering Information

PART

TYPE

MAX9922EVKIT+

EV Kit

+Denotes lead(Pb)-free and RoHS compliant.

Component List

COMPONENT QTY

DESCRIPTION

COMPONENT QTY

DESCRIPTION

249kΩ 0.1ꢀ resistor (0ꢁ03)

4.7µF 10ꢀ, ꢁ.3V X5R ceramic

capacitor (0ꢁ03)

Murata GRM188R70J475K

TDK C1ꢁ08X5R0J475K

1kΩ 0.1ꢀ resistor (0ꢁ03)

100kΩ 5ꢀ resistor (0ꢁ03)

1kΩ 5ꢀ resistors (0ꢁ03)

R5, Rꢁ

0.1µF 10ꢀ, 25V X7R ceramic

capacitors (0ꢁ03)

TDK C1ꢁ08X7R1E104K

Murata GRM188R71E104K

Not installed, resistors—short PC

trace (0ꢁ03)

R7, R8, R9

C2, C7

C3, C4, C5, C8

Cꢁ

Test point

Keystone 5000

SHDN

Not installed, capacitors (0ꢁ03)

High-side current-sense amplifier

(10 µMAX^®)

Maxim MAX9922EUB+

1000pF 10ꢀ, 50V X7R ceramic

capacitor (0ꢁ03)

Murata GRM1885C1H102J

TDK C1ꢁ08X7R1H102K

—

Shunts

PCB: MAX9922/3 Evaluation Kit+

JU1, JU2

JU3

2-pin headers

3-pin header

µMAX is a registered trademark of Maxim Integrated Products, Inc.

0.1Ω 1ꢀ current-sense resistor

(120ꢁ)

IRC LRC-LR120ꢁLF-01-R100-F

________________________________________________________________ Maxim Integrated Products

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

MAX9922 Evaluation Kit

Component Suppliers

SUPPLIER

PHONE

WEBSITE

IRC, Inc.

3ꢁ1-992-7900

209-79ꢁ-2032

770-43ꢁ-1300

847-803-ꢁ100

www.irctt.com

Keystone Electronics Corp.

Murata Electronics North America, Inc.

TDK Corp.

www.keyelco.com

www.murata-northamerica.com

www.component.tdk.com

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

Quick Start

Recommended Equipment

12V, 100mA power supply (VSOURCE)

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

•

3.3V power supply (VDD)

Electronic load capable of sinking 100mA

Digital voltmeter (DVM)

sensing. The output voltage (V

lowing equation:

) is given by the fol-

OUT

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.

⎛

⎞

⎟

= R

× I

+ V

⎜

⎝

OUT

SENSE

SENSE REF

⎠

where R

= 0.1Ω, I

= load current, and V

SENSE

REF

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

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

/2. For unidirectional operation, the output voltage

OUT

) is given by the following equation:

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.

⎛

⎞

= R

× I

SENSE

⎜

⎝

⎟

⎠

OUT

SENSE

Evluates:/MAX923

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.

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.

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.

ꢁ) Connect the DVM across the VOUT pad and the

GND pad.

Table 1. Jumper JU1 Function (SHDN)

7) Turn on the 3.3V power supply.

8) Turn on the 12V power supply.

SHUNT

POSITION

SHDN PIN

MODE

9) Adjust the electronic load current (I

) between

Installed

Connected to GND

Shutdown mode

Normal operation

SENSE

is proportional

0A and 100mA and verify that V

OUT

Connected to VDD

through pullup resistor R4

Not installed*

to V

according to the following equation:

SENSE

*Default position.

⎛

⎞

= R

× I

+ V

⎜

⎝

⎟

⎠

OUT

SENSE

SENSE REF

where R

= R1 and V = V /2.

REF DD

SENSE

_______________________________________________________________________________________

MAX9922 Evaluation Kit

Evluates:/MAX923

Input Differential Signal Range

The MAX9922/MAX9923 feature a proprietary input

structure optimized for small differential signals as low

as 10mV full scale for high efficiency or 100mV full

scale for high dynamic range. For best linearity and

Table 2. Jumper JU2 Function (REF)

SHUNT

POSITION

REF PIN

OPERATION

Installed

Connected to GND

Unidirectional

Bidirectional

accuracy, do not exceed V

of 150mV. ꢂith a

SENSE

Not installed*

Set to V /2

0.1Ω sense resistor installed, the EV kit is optimized for

a 100mA full-scale load current and a 10mV full-scale

sense voltage. For other load-current applications,

choose the appropriate sense resistor according to the

following equation:

*Default position.

Table 3. Jumper JU3 Function (RSB)

SHUNT

POSITION

SENSE_FULL_SCALE

RSB PIN

HIGH SIDE

ENSE

LOAD_FULL_SCALE

1-2*

Connected to VSOURCE

Connected to LOAD

VSOURCE

LOAD

In applications monitoring a high current, ensure that

is able to dissipate its own I²R loss. If the resis-

tor’s power dissipation is exceeded, its value may drift,

or fail altogether.

2-3

SENSE

*Default position.

External Reference

Evaluating the MAX9923T/MAX9923H/

MAX9923F

The MAX9922 EV kit features 2-pin jumper JU2 to sup-

port both unidirectional and bidirectional operation. For

unidirectional current-sense applications, connect the

REF input to GND by placing a shunt across JU2. For

bidirectional operation, connect REF to a reference volt-

The MAX9922 EV kit can also be used to evaluate the

MAX9923T/MAX9923H/MAX9923F ultra-precision,

fixed-gain, high-side current-sense amplifiers. Leave

the FB pin unconnected by uninstalling feedback resis-

tors R2 and R3. Replace U1 with the MAX9923T,

MAX9923H, or the MAX9923F. For bidirectional mode,

age. By default, the EV kit provides a V /2 voltage-

divider when the shunt on JU2 is not installed. In this

mode, V

equals V

when V

equals 0mV.

SENSE

OUT

REF

the output voltage (V

equation:

) is given by the following

OUT

Table 2 summarizes jumper JU2’s function.

Current-Sense Amplifier Supply Input

= A × R

× I

+ V

OUT

SENSE SENSE REF

The MAX9922 EV kit features 3-pin jumper JU3 to select

the current-sense amplifier voltage supply (V

) input.

RSB

where R

= 0.1Ω, I

= load current, V

SENSE

REF

The VRSB pad can be connected to either side of the

current-sense resistor by changing the shunt position of

JU3. Place a shunt across pins 1-2 if the VSOURCE pad

is being used to power VRSB. Place a shunt across pins

2-3 if the LOAD pad is being used to power VRSB.

Table 3 summarizes jumper JU3’s function.

/2, and A is the gain of the device. For unidirec-

DD V

tional operation, the output voltage (V

the following equation:

) is given by

OUT

= A × R × I

SENSE SENSE

OUT

_______________________________________________________________________________________

MAX9922 Evaluation Kit

Evluates:/MAX923

Figure 1. MAX9922 EV Kit Schematic

_______________________________________________________________________________________

MAX9922 Evaluation Kit

Evluates:/MAX923

Figure 2. MAX9922 EV Kit Component Placement Guide—Component Side

_______________________________________________________________________________________

MAX9922 Evaluation Kit

Evluates:/MAX923

Figure 3. MAX9922 EV Kit Component PCB Layout—Component Side

_______________________________________________________________________________________

MAX9922 Evaluation Kit

Evluates:/MAX923

Figure 4. MAX9922 EV Kit PCB Layout—Solder Side

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7

Maxim is a registered trademark of Maxim Integrated Products, Inc.

SPRINGER

MAX9922EVKIT [MAXIM]

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