ZSSC3218 datasheet(13/56 Pages) RENESAS

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ZSSC3218 Datasheet

April 20, 2016

2.3.2.

Analog-to-Digital Converter

An analog-to-digital converter (ADC) is used to digitize the amplifier signal. To allow optimizing the trade-off

between conversion time and resolution, the resolution can be programmed from 12-bit to 18-bit (Adc_bits,

SM_config register; section 3.6.2). The ADC processes differential input signals.

Table 2.4

ADC Conversion Times for a Single Analog-to-Digital Conversion

Resolution (Bits)

Conversion Time in

µs (typical)

140

185

250

335

470

640

890

The ADC can perform an offset shift in order to adapt input signals with offsets to the ADC input range. The shift

feature is enabled by setting SM_config register’s bit [15] = 1 (Shift_method = 1). The respective analog offset

shift can be set up with bits [14:12], Offset in SM_config. The offset shift causes the ADC to perform an additional

amplification of the ADC’s input signal by factor 2. This must be considered for a correct analog sensor setup by

means of the pre-amplifier’s gain, the ADC offset shift, and the potential ADC gain.

The overall analog amplification

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potential use cases:

•

If no offset shift is selected, i.e., Shift_method = 0 and Offset = 000 in SM_config,

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•

If ADC offset shift is selected, i.e., Shift_method = 1 (Offset is arbitrary) in SM_config,

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