LTC1293/LTC1294/LTC1296 OUUWUAPPLICATIS I FOR ATIOExample 2: The same conditions as Example 1 except MSB-First/LSB-First (MSBF) COM = 1V. The resulting input span is 1V ≤ IN+ ≤ 4V. Note The output data of the LTC1293/4/6 is programmed for if IN+ ≥ 4V the resulting DOUT word is all 1’s. If IN+ ≤ 1V MSB-first or LSB-first sequence using the MSB bit. When then the resulting DOUT word is all 0’s. the MSBF bit is a logical one, data will appear on the DOUT line in MSB-first format. Logical zeroes will be filled in Example 3: Let VCC = 5V, V– = –5V, REF+ = 4V, REF– = 1V indefinitely following the last data bit to accommodate and COM = 1V. Bipolar mode of operation. The resulting longer word lengths required by some microprocessors. input span is –2V ≤ IN+ ≤ 4V. When the MSBF bit is a logical zero, LSB first data will For differential input configurations with the same condi- follow the normal MSB first data on the DOUT line. In the tions as in the above three examples the resulting input bipolar mode the sign bit will fill in after the MSB bit for spans are as follows: MSBF = 0 (see Operating Sequence). Example 1 (Diff.): IN– ≤ IN+ ≤ IN– + 3V. Power Shutdowns (PS)Example 2 (Diff.): IN– ≤ IN+ ≤ IN– + 3V. The power shutdown feature of the LTC1293/4/6 is acti- Example 3 (Diff.): IN– – 3V ≤ IN+ ≤ IN– + 3V. vated by making the PS bit a logical zero. If CS remains low after the PS bit has been received, a 12-bit DOUT word with Operating SequenceExample: Differential Inputs (CH4+, CH5–), Unipolar ModeMSB-FIRST DATA (MSBF = 1) tCYC CS DON'T CLK CARE START SEL1 UNI PS D MSBF IN DON'T CARE SGL/ ODD/ SEL0 DIFF SIGN B11 B1 B0 HI-Z FILLED WITH ZEROES DOUT tSMPL tCONV MSB-FIRST DATA (MSBF = 0) tCYC CS DON'T CLK CARE START SEL1 UNI PS DIN DON'T CARE SGL/ ODD/ SEL0 MSBF DIFF SIGN B11 B1 B0 B1 B11 HI-Z FILLED WITH DOUT ZEROES LTC1293 AI05 tSMPL tCONV 129346fs 13