MAX17823H datasheet(37/129 Pages) MAXIM

37 / 129 page

Measurement Alerts

After the measurement cycle, the ALU compares the

enabled measurements to the various configured thresh-

olds (see Table 10), and sets the alert bits before the ALU

data is transferred to the data registers. In oversampling

mode, the alert status is updated after the last over-

sample. The alerts are updated whether or not the data

is moved from the ALU registers to the data registers and

are only updated for those measurements enabled in the

MEASUREEN register.

Voltage Alerts

Use the ALRTOVEN and ALRTUVEN registers to enable

voltage alerts for the cell and auxiliary inputs. If a

cell voltage alert is enabled, the cell input voltage is

compared against the programmable overvoltage and

undervoltage thresholds after every acquisition as shown

in Figure 14. Separate thresholds for setting the alert and

for clearing the alert provide hysteresis. Configure the set

thresholds for cell undervoltage (VUVTHSET) and over-

voltage (VOVTHSET) using the OVTHSET and UVTHSET

registers. Configure the clear thresholds for cell undervolt-

age (VUVTHCLR) and cell overvoltage (VOVTHCLR) using

the OVTHCLR and UVTHCLR registers.

Alert flags in the ALRTOVCELL register are set, if enabled,

when the acquired cell voltage is over VOVTHSET. Alerts

in the ALRTUVCELL register are set, if enabled, when

the acquired cell voltage is under VUVTHSET. The alerts

are cleared when the cell voltage moves in the opposite

direction and crosses the clear threshold. The voltage

must cross the threshold; if it is equal to a threshold,

the alert flag does not change. Therefore, setting the

overvoltage-set threshold to full scale, or setting the

undervoltage-set threshold to zero scale, effectively

disables voltage alerts.

The ALRTOV and ALRTUV bits in the STATUS register

are set when any alert flag is set in the ALRTOVCELL or

ALRTUVCELL registers, respectively. ALRTCELLn is the

logical OR of ALROVCELLn and ALRTUVCELLn.

Cell Mismatch

Enable the mismatch alert to signal when the minimum

and maximum cell voltages differ by more than a specified

voltage. The MSMTCH register sets the 14-bit threshold

(VMSMTCH) for the mismatch alert (ALRTMSMTCH).

Whenever VMAX - VMIN > VMSMTCH, thenALRTMSMTCH

= 1. The alert bit is cleared when a new acquisition does

not exceed the threshold condition. To disable the alert,

write FFCH to the MSMTCH register (default value).

Cell Statistics

The cell numbers with the lowest and highest voltages

are stored in the MINMAXCELL register. When multiple

cells have the same minimum or same maximum volt-

age, only the highest cell position having that voltage is

reported. The sum of all enabled cell voltages is stored

in the TOTAL register as a 16-bit value. For acquisitions

with no enabled cell inputs, the MINMAXCELL and TOTAL

registers are not updated.

Table 10. Measurement Alerts

DESCRIPTION

CONDITION OR RESULT

ALERT BIT

LOCATION

Cell overvoltage (OV)

VCn - VCn-1 > VVOVTHSET

ALRTOV, ALRTOVn

STATUS, ALRTOVCELL

Cell undervoltage (UV)

VCn - VCn-1 < VUVTHSET

ALRTUV, ALRTUVn

STATUS, ALRTUVCELL

Cell Mismatch

VMAX - VMIN > VMSMTCH

ALRTMSMTCH

STATUS

Cell with minimum voltage

n where VCELLn = VMIN

None

MINMAXCELL

Cell with maximum voltage

n where VCELLn = VMAX

None

MINMAXCELL

Total of all cell voltages

Σ VCELLn for n = 1 to 12

None

TOTAL

AUXINx overvoltage

(undertemperature)

VAUXINx > VAINUT

ALTRTCOLD, ALRTOVAINx

STATUS, ALRTOVCELL

AUXINx undervoltage

(overtemperature)

VAUXINx < VAINOT

ALRTHOT, ALRTUVAINx

STATUS, ALRTUVCELL

MAX17823H

12-Channel, High-Voltage

Data-Acquisition Systems

www.maximintegrated.com

Maxim Integrated │ 37

MAX17823H Datasheet(PDF) 37 Page - Maxim Integrated Products

MAX17823H Datasheet(HTML) 37 Page - Maxim Integrated Products

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL