MaximIntegrated│ 10

MAX14921 Evaluation Kit

Evaluates: MAX14921

www.maximintegrated.com

Auxiliary Input Section

The device also has three general-purpose analog

inputs (T1–T3) whose voltages can also be presented

to the ADC. Unlike the cell voltage inputs, the T_ inputs

are neither level shifted nor sampled. The auxiliary

input section provides a way to see these T inputs in

action. Figure 8 and Table 4 detail the available control

and actions.

Streaming Data to a File

The EV kit can collect cell and T_ input data and stream it

to a file. This is when the repeat time parameter is used.

At the default setting of 10ms, data is logged at 100 data

sets per second.

To stream cell data, push the “Stream to File” control. A

“SaveAs” dialog box opens to select a file to write the

datato.Onceafileisselected,clickthe“Save”button.

Streaming continues until the “Stop Streaming” control is

pushed.Notethatyoucanquicklyendupwithlargefiles.

Stream Data File Format

Thedataisstoredinthestreamingfileastext.Thefirst

line indicates what range of cell data is captured, up to

16 cells, and whether each T_ input is also captured or

not.Eachsubsequentlineorpairoflinesrepresentsone

captured data set.

Actual data starts with the second line. This line records

up to 16 cell voltages, starting with the highest numbered

cell down to the first cell (cell 1). If any of the T_ inputs

areenabled,thenextlineisupto3T_inputvoltages.If

noT_inputisenabled,thethirdlineisinsteadthenext

set of cell voltages, captured one repeat time later.

Forexample,inFigure10,thefirstlineofthefileindicates

that all 16 cell voltages are captured, as well as all three

auxiliaryinputs.Thesecondlineshowsthatcell16read

0.0392V and cell 15 read 0.0160V. The third line shows

that T1 read 1.1506V, T2 read 4.0587V, and T3 read

4.0950V. This occurred at one time instant. The fourth

andfifthlinewouldreportthecellandauxiliaryinputs,like

lines 2 and 3, only one repeat time later. Note that at the

default 100 samples per second (10ms repeat time), the

datafilecanquicklygrowquitelarge.

Table 4. EV Kit Auxiliary Input Section Details (Figure 8)

ITEM

LABEL

READ/WRITE

DESCRIPTION

1

Voltage

Read

These are the voltages read from the corresponding T_ input. Each T_ input must

beenabledforitsvoltagetobeacquiredanddisplayed.

2

Enable

Write

ChecktheboxtoenableordisablethecorrespondingT_input.Whenenabled,

the T_ input voltage is read and converted at the same repetition rate as the cell

voltages.

3

Buffer

Write

ChecktheboxtoenableordisabletheoptionalbufferforeachT_input.When

unchecked, the corresponding T_ input connects directly to the ADC. Use this

setting for high-drive analog sources. When checked, the T_ input is unity-gain

buffered to the ADC. Use this for low-drive analog signals.

4

Settling Delay

Write

This is the delay time, in microseconds, from when the device presents a T_ signal

to when the ADC conversion begins.