INA239 datasheet(17/47 Pages) TI

17 / 47 page

Figure 7-4. Noise vs. Conversion Time (Averaging = 1)

Figure 7-5. Noise vs. Conversion Time (Averaging = 128)

Settings for the conversion time and number of conversions averaged impact the effective measurement

resolution. For more detailed information on how averaging reduces noise and increases the effective number of

bits (ENOB) see Section 8.1.3.

7.3.5 Integrated Precision Oscillator

The internal timebase of the device is provided by an internal oscillator that is trimmed to less than 0.5%

tolerance at room temperature. The precision oscillator is the timing source for ADC conversions. The digital

filter response varies with conversion time; therefore, the precise clock ensures filter response and notch

frequency consistency across temperature. On power up, the internal oscillator and ADC take roughly 300 µs

to reach <1% error stability. Once the clock stabilizes, the ADC data output will be accurate to the electrical

specifications provided in Section 6.

7.3.6 Multi-Alert Monitoring and Fault Detection

The INA239-Q1 includes a multipurpose, open-drain ALERT output pin that can be used to report multiple

diagnostics or as an indicator that the ADC conversion is complete when the device is operating in both

triggered and continuous conversion mode. The diagnostics listed in Table 7-1 are constantly monitored and can

be reported through the ALERT pin whenever the monitored output value crosses its associated out-of-range

threshold.

Table 7-1. ALERT Diagnostics Description

INA239-Q1 DIAGNOSTIC

STATUS BIT IN DIAG_ALRT REGISTER

(RO)

OUT-OF-RANGE

THRESHOLD

VALUE

Shunt Under Voltage Limit

SHNTUL

SUVL

0x8000 h

(two's complement)

Shunt Over Voltage Limit

SHNTOL

SOVL

0x7FFF h

(two's complement)

www.ti.com

INA239-Q1

SLYS028A – MAY 2020 – REVISED JUNE 2021

Submit Document Feedback

Product Folder Links: INA239-Q1

INA239 bảng dữ liệu(PDF) 17 Page - Texas Instruments