电压检测MAX110ACPE[1](12)

Low-Cost, 2-Channel, ±14-Bit Serial ADCsMAX110/MAX111

Figure 4. Differential Transfer Function

Figure 5. Unipolar Transfer Function

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Low-Cost, 2-Channel, ±14-Bit Serial ADCs

Figure 6. Detailed Serial-Interface Timing

The ADC serial interface operates with just SCLK, DIN,and DOUT (allow sufficient time for the conversion tocomplete between read/write operations). Achieve con-tinuous operation by connecting BUSYto an uncommit-ted µP I/O or interrupt, to signal the processor when theconversion results are ready. Figures 8a and 8b showthe timing for SPI/MICROWIRE and QSPI operation.The fully static 16-bit I/O register allows infinite timebetween the two 8-bit read/write operations necessaryto obtain the full 16 bits of data with SPI andMICROWIRE. CSmust remain low during the entiretwo-byte transfer (Figure 8a). QSPI allows a full 16-bitdata transfer (Figure 8b).

Interfacing to the 80C32 Microcontroller FamilyFigure 7c shows the general 80C32 connection to theMAX110/MAX111 using Port 1. For a more detailed dis-cussion, see the MAX110 evaluation kit manual.

I/O Shift Register

Serial data transfer is accomplished with a 16-bit fullystatic shift register. The 16-bit control word shifted intothis register during a data-transfer operation controlsthe ADC’s various functions. The MSB (NO-OP)enables/disables transfer of the control word within theADC. A logic 1 causes the remaining 15 bits in the con-trol word to be transferred from the I/O register into thecontrol register when CSgoes high, updating theADC’s configuration and starting a new conversion. If

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MAX110/MAX111