ZHCSRW7 march 2023 AFE781H1 , AFE881H1
PRODUCTION DATA
The AFE881H1 DAC has a 16-bit voltage output, and the AFE781H1 DAC has a 14-bit voltage output. Table 7-1 shows four possible VOUT DAC output ranges. With a voltage-to-current converter stage, the narrow range corresponds to a 4-mA to 20-mA range. The full range allows for undercurrents and overcurrents from 3 mA to 25 mA, and is controlled by DAC_CFG.RANGE.
The AFEx81H1 provide the option to quickly set the DAC output to the value set in the DAC_CLR_CODE register without writing to the DAC_DATA register, referred to as the CLEAR state. Setting the DAC to CLEAR state also sets the DAC output range according to DAC_CFG.CLR_RANGE. For register details, see Table 7-18.
Transitioning from the DAC_DATA to the DAC_CLR_CODE is synchronous to the clock. If slew mode is enabled, the output slews during the transition. Figure 7-37 shows the full AFEx81H1 DAC_DATA signal path. The devices synchronize the DAC_DATA code to the internal clock, causing up to 2.5 internal clock cycles of latency (2 μs) with respect to the rising edge of CS or the end of a UBM command. Update DAC_GAIN and DAC_OFFSET values when DAC_CFG.SR_EN = 0 to avoid an IRQ pulse generated by SR_BUSY.
Set the DAC to CLEAR state either by:
Method 1 is a direct command to the AFEx81H1 to set the DAC to CLEAR state. Set the DAC_CFG.CLR bit to 1h to set the DAC to CLEAR state.
Method 2 is controlled by settings of ALARM_ACT register. For details of conditions and other masks required to use this method, see Table 7-29 and Section 7.3.3.2.
Method 3 supports setting the DAC to CLEAR state without writing to the AFEx81H1. This pin-based DAC CLEAR state function is available only in UBM on the SDI pin. For details of connection options based on communication modes and pins used in each mode, see Section 7.5.1. Set the appropriate pin high to drive the DAC to CLEAR state.