MAX8631XEVKIT 查看數據表（PDF） - Maxim Integrated

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MAX8631XEVKIT

MAX8631X Evaluation Kit

Maxim Integrated 

MAX8631X Evaluation Kit

Component Suppliers

SUPPLIER

PHONE

WEBSITE

Central Semiconductor Corp.

631-435-1110

www.centralsemi.com

Murata Electronics North America, Inc.

770-436-1300

www.murata-northamerica.com

Nichia Corp.

248-352-6575

www.nichia.com

Panasonic Corp.

800-344-2112

www.panasonic.com

TDK Corp.

847-803-6100

www.component.tdk.com

Note: Indicate that you are using the MAX8631X or MAX8631Y when contacting these component suppliers.

Quick Start

Recommended Equipment

Before beginning, the following equipment is needed:

• A 2.7V to 5.5V power supply or a lithium battery

capable of delivering 1.5A

• Two digital multimeters (DMMs)

• Two 200mA loads

• Ammeter (optional)

Procedure

The MAX8631X EV kit is fully assembled and tested.

Follow the steps below to verify board operation:

1) Preset the power supply to between 2.7V and 5.5V.

2) Turn off the power supply. Caution: Do not turn on

the power supply until all connections are com-

pleted.

3) Verify that the shunt on JU3 is connected to OFF

(pins 2-3). Verify that the shunt on JU5 is connected

to ON (pins 1-2). Verify that there is a shunt on JU4.

Verify that there is no shunt on JU1 and JU2.

4) Connect the positive power-supply terminal to the

pad on the EV kit labeled IN.

5) Connect the power-supply ground terminal to the

pad on the EV kit labeled GND.

6) Connect a DMM across the LDO1 pad on the EV kit

and the GND pad on the EV kit.

7) Connect a DMM across the LDO2 pad on the EV kit

and the GND pad on the EV kit.

8) Turn on the power supply and verify that the main

LEDs are lit.

9) Push S2 for only a short duration to verify that the

flash LED module lights. Holding S2 down for long

durations may damage the flash LED module. See

the Detailed Description section for testing the dim-

ming and shutdown features.

10) Remove the shunt from the OFF position (pins 2-3)

of JU3 and place on the ON position (pins 1-2) of

JU3.

11) Verify the voltage at LDO1 is near 2.6V.

12) Connect a 200mA load between LDO1 and GND.

13) Verify the voltage at LDO1 is near 2.6V.

14) Verify the voltage at LDO2 is near 1.8V.

15) Connect a 200mA load between LDO2 and GND.

16) Verify the voltage at LDO2 is near 1.8V.

Detailed Description

LED Dimming of the Main Display

To test the dimming feature, press the button labeled

DIM MAIN. Each button depression dims the main

LEDs by 3.125%. Due to the logarithmic response of

the human eye, it takes many depressions of the button

to visually notice dimming. The 31st pulse reduces the

current to 3.125%. The 32nd pulse sets the LED current

back to 100%. Refer to the MAX8631X data sheet for

more information on the dimming feature.

Single-Wire Pulse Dimming for Main or

Flash Using External Pulse Generators

To use an external pulse generator in place of the pulse

generator included with the EV kit or to reduce the num-

ber of control traces, the MAX8631X supports serial-

pulse dimming. Connect the output of the external

pulse generator to ENM1 or ENM2 to enable single-wire

pulse dimming of the main LEDs. Use ENF for single-

wire pulse dimming of the flash LED module. The

ground of the external pulse generator should be con-

nected to the EV kit pad labeled GND. Ensure that

there is a shunt on JU5 connected to ON (pins 1-2).

When ENM1 and ENM2 (or ENF) go high simultaneous-

ly, the main (or flash) LEDs are enabled at full bright-

ness. Each subsequent low-going pulse (500ns to

250µs pulse width) reduces the LED current by 3.125%

(1/32), so after one pulse the LED current is 96.9% (or

31/32). The 31st pulse reduces the current to 3.125%.

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