LTC2424/LTC2428 WUTYPICAL PERFOR A CE CHARACTERISTICSINL vs Output RateINL vs Output RateResolution vs Output Rate 20 20 24 VCC = 5V VCC = 3V V T CC = 5V A = 25°C VREF = 5V VREF = 2.5V V T REF = 5V A = 90°C FO = EXTERNAL FO = EXTERNAL f T 18 18 O = EXTERNAL A = –45°C 22 16 T 16 A = –45°C T T A = –45°C A = 25°C 20 14 14 T TA = 25°C RESOLUTION (BITS) T TUE RESOLUTION (BITS) A = 90°C TUE RESOLUTION (BITS) A = 90°C 18 12 12 10 10 16 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 0 7.5 25 50 75 100 OUTPUT RATE (Hz) OUTPUT RATE (Hz) OUTPUT RATE (Hz) 24248 G27 24248 G28 24248 G29 UUUPIN FUNCTIONSGND (Pins 1, 6, 16, 18, 22, 27, 28): Ground. Should be CH1 (Pin 10): Analog Multiplexer Input. connected directly to a ground plane through a minimum CH2 (Pin 11): Analog Multiplexer Input. length trace or it should be the single-point-ground in a single-point grounding system. CH3 (Pin 12): Analog Multiplexer Input. VCH4 (Pin 13): Analog Multiplexer Input. No connect on the CC (Pins 2, 8): Positive Supply Voltage. 2.7V ≤ VCC ≤ 5.5V. Bypass to GND with a 10µF tantalum capacitor in LTC2424. parallel with 0.1µF ceramic capacitor as close to the part CH5 (Pin 14): Analog Multiplexer Input. No connect on the as possible. LTC2424. FSSET (Pin 3): Full-Scale Set Input. This pin defines the CH6 (Pin 15): Analog Multiplexer Input. No connect on the full-scale input value. When VIN = FSSET, the ADC outputs LTC2424. full scale (FFFFFH). The total reference voltage (VREF) is FS CH7 (Pin 17): Analog Multiplexer Input. No connect on the SET – ZSSET. LTC2424. ADCIN (Pin 4): Analog Input. The input voltage range is – 0.125 • V CLK (Pin 19): Shift Clock for Data In. This clock synchro- REF to 1.125 • VREF. For VREF > 2.5V the input voltage range may be limited by the pin absolute maxi- nizes the serial data transfer into the MUX. For normal mum rating of – 0.3V to V operation, drive this pin in parallel with SCK. CC + 0.3V. ZSCSMUX (Pin 20): MUX Chip Select Input. A logic high on SET (Pin 5): Zero-Scale Set Input. This pin defines the zero-scale input value. When V this input allows the MUX to receive a channel address. A IN = ZSSET, the ADC outputs zero scale (00000 logic low enables the selected MUX channel and connects H). For pin compatibility with the LTC2404/ LTC2408 this pin must be grounded. it to the MUXOUT pin for A/D conversion. For normal operation, drive this pin in parallel with CSADC. MUXOUT (Pin 7): MUX Output. This pin is the output of the multiplexer. Tie to ADCIN for normal operation. DIN (Pin 21): Digital Data Input. The multiplexer address is shifted into this input on the last four rising CLK edges CH0 (Pin 9): Analog Multiplexer Input. before CSMUX goes low. 9