Datasheet LTC1594, LTC1598 (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | 8-Channel, Micropower Sampling 12-Bit Serial I/O A/D Converter |
| Pages / Page | 24 / 10 — APPLICATIONS INFORMATION. OVERVIEW. SERIAL INTERFACE. Figure 1. … |
| File Format / Size | PDF / 246 Kb |
| Document Language | English |
APPLICATIONS INFORMATION. OVERVIEW. SERIAL INTERFACE. Figure 1. LTC1594/LTC1598 Operating Sequence Example: CH2, GND
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LTC1594/LTC1598
U U W U APPLICATIONS INFORMATION OVERVIEW
and can operate with reduced spans to 1.5V. Reducing the spans allow them to achieve 366μV resolution. The LTC1594/LTC1598 are micropower, 12-bit sampling A/D converters that feature a 4- and 8-channel multi- The LTC1594/LTC1598 provide separate MUX output plexer respectively. They typically draw only 320μA of and ADC input pins to form an ideal MUXOUT/ADCIN supply current when sampling at 16.8kHz. Supply cur- loop which economizes signal conditioning. The MUX rent drops linearly as the sample rate is reduced (see and ADC of the devices can also be controlled individually Supply Current vs Sample Rate). The ADCs automatically through separate chip selects to enhance flexibility. power down when not performing conversions, drawing only leakage current. The LTC1594 is available in a 16-pin
SERIAL INTERFACE
narrow SO package and the LTC1598 is packaged in a 24-pin SSOP. Both devices operate on a single supply For this discussion we will assume that CSMUX and from 4.5V to 5.5V. CSADC are tied together and will refer to them as simply CS, unless otherwise specified. The LTC1594/LTC1598 contain a 12-bit, switched- capacitor ADC, sample-and-hold, serial port and an The LTC1594/LTC1598 communicate with the micropro- external reference input pin. In addition, the LTC1594 has cessor and other external circuitry via a synchronous, a 4-channel multiplexer and the LTC1598 provides an half duplex, 4-wire interface (see Operating Sequences in 8-channel multiplexer (see Block Diagram). They can Figures 1 and 2). measure signals floating on a DC common mode voltage tCYC CSMUX = CSADC = CS tsuCS CLK EN D1 DIN DON’T CARE D2 D0 NULL Hi-Z Hi-Z D BIT OUT B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0* tSMPL tCONV CH0 TO CH7 tON ADCIN = MUXOUT COM = GND *AFTER COMPLETING THE DATA TRANSFER, IF FURTHER CLOCKS ARE APPLIED WITH CS LOW, THE ADC WILL OUTPUT LSB-FIRST DATA THEN FOLLOWED WITH ZEROS INDEFINITELY 1594/98 F01
Figure 1. LTC1594/LTC1598 Operating Sequence Example: CH2, GND
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U U W U APPLICATIONS INFORMATION OVERVIEW
and can operate with reduced spans to 1.5V. Reducing the spans allow them to achieve 366μV resolution. The LTC1594/LTC1598 are micropower, 12-bit sampling A/D converters that feature a 4- and 8-channel multi- The LTC1594/LTC1598 provide separate MUX output plexer respectively. They typically draw only 320μA of and ADC input pins to form an ideal MUXOUT/ADCIN supply current when sampling at 16.8kHz. Supply cur- loop which economizes signal conditioning. The MUX rent drops linearly as the sample rate is reduced (see and ADC of the devices can also be controlled individually Supply Current vs Sample Rate). The ADCs automatically through separate chip selects to enhance flexibility. power down when not performing conversions, drawing only leakage current. The LTC1594 is available in a 16-pin
SERIAL INTERFACE
narrow SO package and the LTC1598 is packaged in a 24-pin SSOP. Both devices operate on a single supply For this discussion we will assume that CSMUX and from 4.5V to 5.5V. CSADC are tied together and will refer to them as simply CS, unless otherwise specified. The LTC1594/LTC1598 contain a 12-bit, switched- capacitor ADC, sample-and-hold, serial port and an The LTC1594/LTC1598 communicate with the micropro- external reference input pin. In addition, the LTC1594 has cessor and other external circuitry via a synchronous, a 4-channel multiplexer and the LTC1598 provides an half duplex, 4-wire interface (see Operating Sequences in 8-channel multiplexer (see Block Diagram). They can Figures 1 and 2). measure signals floating on a DC common mode voltage tCYC CSMUX = CSADC = CS tsuCS CLK EN D1 DIN DON’T CARE D2 D0 NULL Hi-Z Hi-Z D BIT OUT B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0* tSMPL tCONV CH0 TO CH7 tON ADCIN = MUXOUT COM = GND *AFTER COMPLETING THE DATA TRANSFER, IF FURTHER CLOCKS ARE APPLIED WITH CS LOW, THE ADC WILL OUTPUT LSB-FIRST DATA THEN FOLLOWED WITH ZEROS INDEFINITELY 1594/98 F01
Figure 1. LTC1594/LTC1598 Operating Sequence Example: CH2, GND
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