ZSSC3018 Datasheet

© 2020 Renesas Electronics Corporation

13

September 8, 2020

If needed, the polarity of the sensor bridge gain can be reversed by setting the Gain_polarity bit, which is bit 6 in the SM_config register (see

section 3.6.2). Changing the gain polarity is achieved by inverting the chopper clock. Table 2.3 gives the settings for the Gain_polarity bit. This

feature enables applying a sensor to the ZSSC3018 with swapped input signals at INN and INP; e.g., to avoid crossing wires for the final sensor

module’s assembly.

Table 2.3 Gain Polarity

Gain_polarity (SM_config Bit 6)

Gain

Setting Description

0

+1

No polarity change.

1

-1

Gain polarity is inverted.

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 (see Adc_bits, SM_config register; section 3.6.2). The ADC processes

differential input signals.

Table 2.4 ADC Conversion Times for a Single A2D Conversion

Resolution [Bits]

Conversion Time in µs (typical)

12

140

13

185

14

250

15

335

16

470

17

640

18

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 registers’ bit[15] = 1 (Shift_method = 1). The respective analog offset shift can be set up with bits[14:12], the Offset bit field in

SM_config.

Note: The offset shift causes the ADC to perform an additional amplification of the ADC’s input signal by a factor of 2. This must be considered

for a correct analog sensor setup using the pre-amplifier’s gain, the ADC offset shift, and the potential ADC gain.



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



If ADC offset shift is selected, i.e. Shift_method = 1 and Offset

 000 in SM_config: