male cable. If the only available serial port uses a

25-pin connector, a standard 25-pin to 9-pin

adapter is required. The EV kit software checks the

modem status lines (CTS, DSR, DCD) to confirm

that the correct port has been selected.

7) Start the MAX1132 program by opening its icon in

the Start | Programs menu.

8) Turn on the power supply and slide SW1 to the ON

position on the 68HC16MODULE-DIP module.

Press the OK button to automatically connect and

download the KIT1132.C16 file to the module.

9) Apply the input signal across the pins of JU2.

Observe the readout on the screen.

Detailed Description

of Software

The evaluation software main window controls the

active control word bits, serial clock speed, and sam-

ple rate. It displays the voltage and output code, as

well as some statistics of the input signal. A separate

graph window shows the data changing in real time.

The update rate is limited to about 10 samples per sec-

ond, due to COM port bandwidth limitations.

Controls

The control word is divided into several fields. To

change the active control word, drop down the appro-

priate field’s combo box and select the desired option.

If the QSPI clock is set to STOP, the configuration data

is not sent until the READ button is clicked.

Statistics

The minimum and maximum fields show the lowest and

highest readings acquired. The average and RMS

fields show the running mean and root-mean-square of

the input signal. The Clear button resets the statistics.

To remove offset errors, first apply zero volts to the

active input channel, clear statistics, acquire some

samples, and then check Tare. This offset is now sub-

tracted from all subsequent voltage measurements.

Sampling

To sample data at rates up to 125ksps, select the

Sample menu item, make your selections, and click the

Begin Sampling button. Sample size is restricted to a

power of two to permit FFT processing once the data is

saved to a file. After the samples have been collected,

the data is automatically uploaded to the host and is

MAX1132 Evaluation Kit/Evaluation System

_______________________________________________________________________________________

3

JUMPER

POSITION

FUNCTION

—

1-2

Operate

JU1

Open

SHDN is controlled by 68HC16 module

—

2-3

Shutdown

JU2

Closed

Measure short circuit (zero volts)

—

Open

Apply input signal at JU2

JU3

Closed

Illegal

—

Open*

Enable internal reference, or apply an external reference

JU4

Closed

Disable internal reference

—

Open*

Enable internal reference

—

1

User-programmable output pin P2

JU5

2

User-programmable output pin P1

—

3

User-programmable output pin P0

Table 1. Jumper Functions

*Default configuration.