Datasheet LTC1392 (Analog Devices) - 7

LTC1392
U U W U APPLICATIONS INFORMATION MSB-First Data (MSBF = 1)
tCYC CS tsuCS CLK tWAKEUP SEL1 SEL0 DIN START MSBF Hi-Z Hi-Z DOUT B9 B8 B7 B6 B5 B4 B3 B2 B1 B0 FILLED WITH ZEROS tSMPL tCONV tCYC CS tsuCS CLK tWAKEUP SEL1 SEL0 DIN START MSBF Hi-Z Hi-Z DOUT B9 B8 B7 B6 B5 B4 B3 B2 B1 B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 FILLED WITH ZEROS tCONV tSMPL LTC1392 • F01
Figure 1
temperature measurement or a 10µs delay for other mea- DIN input which configures the LTC1392 and starts the surements, followed by a 4-bit input word which config- conversion. Further inputs on the DIN input are then ures the LTC1392 for the current conversion. This data ignored until the next CS cycle. The four bits of the input word is shifted into the DIN input. DIN is then disabled from word are defined as follows: shifting in any data and the DOUT pin is configured from three-state to an output pin. A null bit and the result of the
BIT 3 BIT 2 BIT 1 BIT 0
current conversion are serially transmitted on the falling Start Select 1 Select 0 MSBF CLK edge onto the DOUT line. The format of the A/D result can be either MSB-first sequence or MSB-first sequence
Start Bit
followed by an LSB-first sequence. This provides easy The first “logic one” clocked into the D interface to MSB- or LSB-first serial ports. Bringing CS IN input after CS goes low is the Start Bit. The Start Bit initiates the data high resets the LTC1392 for the next data exchange. transfer and all leading zeros which precede this logical one will be ignored. After the Start Bit is received the
INPUT DATA WORD
remaining bits of the input word will be clocked in. Further Data transfer is initiated by a falling chip select (CS) signal. input on the DIN pin are then ignored until the next CS After CS falls, the LTC1392 looks for a start bit. Once the cycle. start bit is received, the next three bits are shifted into the 7