1) To monitor the MAX110 supply current, install a cur-

rent meter before applying power to the MAX110 EV

Typical supply current is less than 1mA during nor-

mal operation, and less than 4µA in shutdown mode

if the internal RC oscillator is used.

2) Follow the quick-start instructions to start the

MAX110 software on the IBM PC.

3) From the Control Panel screen, press “S” to enter

the Shutdown Power Cycling screen.

4) From the Shutdown Power Cycling screen, press

“D” to shut down the MAX110. The supply current

should drop to less than 4µA.

5) From the Shutdown Power Cycling screen, press

“U” to power-up the MAX110. The supply current

should settle at less than 1mA. There will be short

current spikes whenever a command is sent to the

MAX110.

A typical application may sample the MAX110 at regu-

lar intervals, keeping the MAX110 shut down between

samples. This type of usage can be evaluated by using

the “P” command in the Shutdown Power Cycling

screen. The power-cycling loop repeatedly puts the

MAX110 into sleep mode for a user-specified length of

time, wakes up the MAX110, takes a reading, and

powers the MAX110 down again. The “P” command

runs continuously, until halted by either the “U” or “D”

command.

The parameters that pertain to the “P” command are as

follows: the state of the PD and PDX bits before and

after shutdown, the sleep time, and the optional NOOP,

AUTO NULL, and GAIN CAL cycles.

The sampling rate is determined by setting the sleep

time, which is the length of time the program keeps the

MAX110 in shutdown mode. The program allows a

maximum sleep time of 65 seconds.

If the internal RC oscillator is used, activating the PDX

bit may cause the BUSY line to remain low. This condi-

tion should be cleared by starting the power-up

sequence with a configuration word whose MSB is 0 (a

NOOP cycle). If an external oscillator is used, the PDX

bit has no effect and the NOOP cycle is not required.

Supply current will not be as low as in the internal RC

oscillator mode, unless the external oscillator is halted

during shutdown.

The PDX power-down bit has no effect unless the

internal RC oscillator is being used. Normally, the PD

and PDX bits should be set to 1 in shutdown mode, and

both should be 0 in active mode.

Measuring Supply Current

Jumper J9 can be used to measure the supply current

drawn by the MAX110 IC. To measure the supply current,

use the following procedure:

1) Exit the MAX110 software and then turn off the

MAX110 EV kit power.

2) Carefully cut the printed circuit board trace at

location J9.

3) Connect a current meter between the two pins of

J9. The direction of current flow is marked with an

arrow on the board.

4) Turn on the MAX110 EV kit and restart the MAX110

program to evaluate the desired operating mode.

5) Observe the supply current in both operating and

shutdown modes.

To restore the MAX110 EV kit, use the following

procedure:

1) Turn off the MAX110 EV kit power.

2) Disconnect the current meter.

3) Install a 2-pin header and jumper at J9, or use a

small piece of wire to reconnect J9.

current can be measured in a similar way. Remove the

shunt from J4 1-2 and connect a current meter. Current

will flow from J4 pin 2 to J4 pin 1. Or, the current meter

to the -5V edge pad.

__Detailed Description of Software

When starting the MAX110 program from the DOS

prompt, several command-line options are available.

For a list of available options, run MAX110 with the “?”

command-line option. Refer to Table 3.

When the MAX110 program begins operation, it is in its

Opening screen. Use the space bar to select the serial

communications port to which you have connected the

80C32 module. Press the ENTER key to advance to the

Terminal screen.

The MAX110 program displays its Terminal screen

when it is establishing communications with the 80C32

module. When power is applied to the 80C32 module

or reset is pressed, banner message identifying the

80C32 module is displayed. After the module com-

pletes its self check, it says that all tests have passed.

At this point, use the ALT+L command to load the RAM

resident program into the 80C32 module. After the RAM

resident program has been loaded, use the ALT+C

command to advance to the Control Panel screen.

MAX110 Evaluation System/Evaluation Kit

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