MAX6683 Evaluation System/Evaluation Kit

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Detailed Description

User-Interface Panel

The user interface is easy to operate using the mouse,

or by using the tab key to navigate with the arrow keys.

The checkboxes, edit fields, and radio buttons corre-

spond to bits in the internal registers. By clicking on

them, the correct SMBus write operation is generated

to update the registers.

The program monitors for an alert interrupt and continu-

ally polls the device for new temperature, voltage, and

status data. To disable the continuous polling of data,

uncheck the Automatic Read checkbox. To change

the temperature or voltage threshold comparison regis-

ters, select the appropriate data field and type in the

new value. Pressing Enter, after typing in the new val-

ues, updates the internal registers.

The message ALERT appears whenever an interrupt

condition occurs. To clear the interrupt, first eliminate the

condition that caused it and then click on Read Status.

Simple SMBus Commands

There are two methods for communicating with the

MAX6683: through the normal user-interface panel or

through the SMBus commands available from pressing

the MAXSMBus.. button. A display appears that allows

the SMBus protocols, such as Read Byte and Write

Byte, to be executed. To stop normal user-interface

execution so that it does not override the manually set

values, turn off the update timer that slaves the pro-

gram to the conversion rate by unchecking the

Automatic Read checkbox.

The SMBus dialog boxes accept numeric data in bina-

ry, decimal, or hexadecimal. Hexadecimal numbers

should be prefixed by $ or 0x. Binary numbers must be

exactly eight digits.

Note: In places where the slave address asks for an 8-

bit value, it must be the 7-bit slave address of the

MAX6683 as determined by the address pin (ADD) with

the last bit set to 1 for a read operation and 0 for a write.

Data Logging

Check the Data Logging checkbox to activate data

logging. Data logging saves temperature, voltage, and

status data to a text file that includes a time/date stamp

next to each data point. If Automatic Read is enabled,

data is sampled at 2Hz; however, the data is logged to

the file only if the temperature, voltage, or status

change. This slows the growth of the data-logging file.

When Automatic Read is disabled, the data is logged

each time the Read All button is clicked. To stop data

logging, uncheck the Data Logging checkbox.

Jumper and Switch Settings

Jumper 1 (JU1) sets the MAX6683 slave address. The

default address is 0010 101 (ADD = VCC); see Table 1

for a complete list of addresses. The slide switch, SW1,

provides a means to force a reset. This switch disables

power to the device.

Evaluating the MAX6652

The MAX6683 EV kit can also evaluate the MAX6652.

Remove the MAX6683 from the board and install the

MAX6652.

The MAX6652 and MAX6683 monitor different voltages.

See Table 2.

When evaluating the MAX6652 with the MAX6683 soft-

the 1.8V nominal voltage, and the 5V nominal voltage are

incorrect. However, the ADC output code, shown in

parentheses next to the voltage, is correct. Use the equa-

tions shown below to calculate the actual voltages:

.

V

V ADC output code

Voltage on pin

V ADC output code

Voltage on pin

V ADC output code

×

=

×

=

×

5

192

1

12

192

3

33

192

Table 2. Voltage Monitor Differences

Between MAX6652 and MAX6683

SHUNT

LOCATION

ADD

CONNECTION

MAX6683

ADDRESS

0x28

To GND

0010 100Y

0x2A

To VCC

0010 101Y

0x2C

To SDA

0010 110Y

0x2E

To SCL

0010 111Y

Table 1. JU1 Shunt Settings for SMBus

Address

Note: The first 7 bits shown are the address. Y (bit 0) is the

SMBus read/write bit. This bit is a 1 for a read operation and

zero for a write.

PIN

MAX6652 (V)

MAX6683 (V)

5

3.3

1

12

1.8

3

3.3

5