AMC7836IPAPR datasheet(30/91 Pages) TI2

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LV_ADC16

AVDD

LV_ADC20

AGND

S(W) is closed during acquisition.

S(W) is open during conversion.

C(SAMPLE)

S(W)

ADC_0

ADC_15

R(MUX)

3.125 V

Scaling Network

AMC7836

SLAS986D – NOVEMBER 2014 – REVISED FEBRUARY 2018

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7.3.2 Analog-to-Digital Converter (ADC)

The AMC7836 features a monitoring system centered on a 12-bit SAR (successive approximation register) ADC

fronted by a 22-channel multiplexer and an on-chip track-and-hold circuit. The monitoring systems is capable of

sensing up to 16 external bipolar inputs (–12.5 to 12.5 V range), five external unipolar inputs (0 to 5 V range),

and an internal analog temperature sensor.

The ADC operates from an internal 2.5 V reference (Vref, measured at the REF_CMP pin) and the input range is

0 V to 2 × Vref. The external bipolar inputs to the ADC are internally mapped to this range. The ADC timing

signals are derived from an on-chip temperature-compensated oscillator. The conversion results can be

accessed through the device serial interface.

7.3.2.1 Analog Inputs

The AMC7836 has 21 analog inputs for external voltage sensing. Sixteen of these inputs (ADC_0 through

ADC_15) are bipolar and the other five (LV_ADC16 through LV_ADC20) are unipolar. Figure 51 shows the

equivalent circuit for the external analog-input pins. All switches are open while the ADC is in the IDLE state.

Figure 51. ADC External Inputs Equivalent Circuit

To achieve the specified performance, especially at higher input frequencies, driving each analog input pin with a

low impedance source is recommended. An external amplifier can also be used to drive the input pins.

AMC7836IPAPR 数据表(PDF) 30 Page - Texas Instruments