Datasheet LTC2983 (Analog Devices) - 5

LTC2983
DIGITAL INPUTS AND DIGITAL OUTPUTS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
External SCK Frequency Range l 0 2 MHz External SCK LOW Period l 250 ns External SCK HIGH Period l 250 ns t1 CS↓ to SDO Valid l 0 200 ns t2 CS↑ to SDO Hi-Z l 0 200 ns t3 CS↓ to SCK↑ l 100 ns t4 SCK↓ to SDO Valid l 225 ns t5 SDO Hold After SCK↓ l 10 ns t6 SDI Setup Before SCK↑ l 100 ns t7 SDI HOLD After SCK↑ l 100 ns High Level Input Voltage CS, SDI, SCK, RESET l VDD – 0.5 V Low Level Input Voltage CS, SDI, SCK, RESET l 0.5 V Digital Input Current CS, SDI, SCK, RESET l –10 10 µA Digital Input Capacitance CS, SDI, SCK, RESET 10 pF LOW Level Output Voltage (SDO, INTERRUPT) IO = –800µA l 0.4 V High Level Output Voltage (SDO, INTERRUPT) IO = 1.6mA l VDD – 0.5 V Hi-Z Output Leakage (SDO) l –10 10 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings than one third that of the first thousand hours with a continuing trend may cause permanent damage to the device. Exposure to any Absolute toward reduced drift with time. Long-term stability will also be affected by Maximum Rating condition for extended periods may affect device differential stresses between the IC and the board material created during reliability and lifetime. board assembly.
Note 2:
All voltage values are with respect to GND.
Note 14:
Hysteresis in output voltage is created by package stress
Note 3:
Full scale ADC error. Measurements do not include reference error. that differs depending on whether the IC was previously at a higher or
Note 4:
Guaranteed by design, not subject to test. lower temperature. Output voltage is always measured at 25°C, but the IC is cycled to the hot or cold temperature limit before successive
Note 5:
The input referred noise includes the contribution of internal measurements. Hysteresis measures the maximum output change for the calibration operations. averages of three hot or cold temperature cycles. For instruments that
Note 6:
MUX configuration delay = default 1ms are stored at well controlled temperatures (within 20 or 30 degrees of
Note 7:
Global configuration set to 60Hz rejection. operational temperature), it is usually not a dominant error source. Typical
Note 8:
Global configuration set to 50Hz rejection. hysteresis is the worst-case of 25°C to cold to 25°C or 25°C to hot to
Note 9:
Global configuration default 50Hz/60Hz rejection. 25°C, preconditioned by one thermal cycle.
Note 10:
The exact value of V
Note 15:
Differential Input Range is ±V REF is stored in the LTC2983 and used REF/2. for all measurement calculations. Temperature coefficient is measured
Note 16:
RTD and thermistor measurements are made ratiometrically. As a by dividing the maximum change in output voltage by the specified result current source excitation variation does not affect absolute accuracy. temperature range. Choose an excitation current such that largest sensor or RSENSE resistance
Note 11:
Analog power-up. Command status register inaccessible during value, when driven by the nominal excitation current, will drop 1V or less. this time. The extended ADC input range will accommodate variation in excitation
Note 12:
Digital initialization. Begins at the conclusion of Analog Power- current and the ratiometric calculation will negate the absolute value of the Up. Command status register is 0 × 80 at the beginning of digital excitation current. initialization and 0 × 40 at the conclusion.
Note 17:
Do not apply voltage or current sources to these pins. They must
Note 13:
Long-term stability typically has a logarithmic characteristic be connected to capacitive loads only, otherwise permanent damage may and therefore, changes after 1000 hours tend to be much smaller than occur. before that time. Total drift in the second thousand hours is normally less
Note 18:
Input leakage measured with VIN = –10mV and VIN = 2.5V. 2983fc For more information www.linear.com/LTC2983 5 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Complete System Electrical Characteristics Pin Configuration ADC Electrical Characteristics Reference Electrical Characteristics Digital Inputs and Digital Outputs Typical Performance Characteristics Pin Functions Block Diagram Test Circuits Timing Diagram Overview Applications Information Thermocouple Measurements Diode Measurements RTD Measurements Thermistor Measurements Direct ADC Measurements Supplemental Information Fault Protection and Anti-Aliasing 2- and 3-Cycle Conversion Modes Running Conversions Consecutively on Multiple Channels MUX Configuration Delay Global Configuration Register Custom Thermocouples Custom RTDs Custom Thermistors Package Description Revision History Typical Application Related Parts