Datasheet LTC1285, LTC1288 (Analog Devices) - 7

LTC1285/LTC1288
W U TYPICAL PERFORMANCE CHARACTERISTICS Minimum Clock Frequency Digital Input Logic Threshold Input Channel Leakage Current for 0.1 LSB Error vs Temperature vs Supply Voltage vs Temperature
120 3.0 1000 VCC = 2.7V TA = 25°C VCC = 2.7V VREF = 2.5V VREF = 2.5V 100 2.5 100 80 2.0 10 60 1.5 1 40 1.0 ON CHANNEL CLOCK FREQUENCY (kHz) LEAKAGE CURRENT (nA) OFF CHANNEL 0.1 20 0.5 2 0 DIGITAL INPUT LOGIC THRESHOLD VOLTAGE (V) 0 0.01 0 10 20 30 40 50 60 70 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 –55 –35 –15 5 25 45 65 85 105 125 TEMPERATURE (°C) SUPPLY VOLTAGE (V) TEMPERATURE (°C) LTC1285/88 • TPC22 LTC1285/88 • TPC23 LTC1285/88 • TPC24
U U U PIN FUNCTIONS LTC1285 LTC1288 VREF (Pin 1):
Reference Input. The reference input defines
CS/SHDN (Pin 1):
Chip Select Input. A logic low on this the span of the A/D converter. input enables the LTC1288. A logic high on this input disables and powers down the LTC1288.
IN+ (Pin 2):
Positive Analog Input.
CH0 (Pin 2):
Analog Input.
IN – (Pin 3):
Negative Analog Input.
CH1 (Pin 3):
Analog Input.
GND (Pin 4):
Analog Ground. GND should be tied directly to an analog ground plane.
GND (Pin 4):
Analog Ground. GND should be tied directly to an analog ground plane.
CS/SHDN (Pin 5):
Chip Select Input. A logic low on this input enables the LTC1285. A logic high on this input
DIN (Pin 5):
Digital Data Input. The multiplexer address is disables and powers down the LTC1285. shifted into this input.
DOUT (Pin 6):
Digital Data Output. The A/D conversion
DOUT (Pin 6):
Digital Data Output. The A/D conversion result is shifted out of this output. result is shifted out of this output.
CLK (Pin 7):
Shift Clock. This clock synchronizes the serial
CLK (Pin 7):
Shift Clock. This clock synchronizes the data transfer and determines conversion speed. serial data transfer and determines conversion speed.
VCC (Pin 8):
Power Supply Voltage. This pin provides
VCC/VREF (Pin 8):
Power Supply and Reference Voltage. power to the A/D converter. It must be kept free of noise This pin provides power and defines the span of the A/D and ripple by bypassing directly to the analog ground converter. It must be kept free of noise and ripple by plane. bypassing directly to the analog ground plane. 7