LTC2470/LTC2472 Typical perForMance characTerisTics (TA = 25°C, unless otherwise noted)Power Supply Rejectionvs Frequency Applied to VCCConversion Time vs TemperatureVREF vs VCC 0 4.4 1.250345 T T A = 25°C A = 25°C 1.250340 –20 4.3 VCC = 2.7V 1.250335 –40 4.2 1.250330 (V) –60 4.1 VCC = 4.1V 1.250325 V REF REJECTION (dB) 1.250320 –80 4.0 CONVERSION TIME (ms) 1.250315 V –100 3.9 CC = 5.5V 1.250310 –120 3.8 1.250305 1 10 100 1k 10k 100k 1M 10M –50 –25 0 25 50 75 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 FREQUENCY AT VCC (Hz) TEMPERATURE (°C) VCC (V) 24702 G010 24702 G11 24702 G12 pin FuncTions REFOUT (Pin 1): Reference Output Pin. Nominally 1.25V, SDO (Pin 6): Three-State Serial Data Output. SDO is used this voltage sets the full-scale input range of the ADC. For for serial data output during the DATA INPUT/OUTPUT noise and reference stability connect to a 0.1µF capacitor state. This pin goes Hi-Z when CS is high. tied to GND. This capacitor value must be less than or GND (Pins 7, 11, Exposed Pad Pin 13 – DFN Package): equal to the capacitor tied to the reference compensation Ground. Connect directly to the ground plane through a pin (COMP). REFOUT cannot be overdriven by an external low impedance connection. reference. REF– (Pin 8): Negative Reference Input to the ADC. The COMP (Pin 2): Internal Reference Compensation Pin. For voltage on this pin sets the zero input to the ADC. This low noise and reference stability, tie a 0.1μF capacitor pin should be tied directly to ground or the ground sense to GND. of the input sensor. CS (Pin 3): Chip Select (Active LOW) Digital Input. A LOW IN+ (LTC2472), IN (LTC2470) (Pin 9): Positive input volt- on this pin enables the SDO output. A HIGH on this pin age for the LTC2472 differential device. ADC input for the places the SDO output pin in a high impedance state and LTC2470 single-ended device. any inputs on SDI and SCK will be ignored. IN– (LTC2472), GND (LTC2470) (Pin 10): Negative input SDI (Pin 4): Serial Data Input Pin. This pin is used to pro- voltage for the LTC2472 differential device. GND for the gram the sleep mode and the 208sps/833sps output rate. LTC2470 single-ended device. SCK (Pin 5): Serial Clock Input. SCK synchronizes the V serial data input/output. Once the conversion is complete, CC (Pin 12): Positive Supply Voltage. Bypass to GND with a 10μF capacitor in parallel with a low-series-induc- a new data bit is produced at the SDO pin following each tance 0.1μF capacitor located as close to the device as SCK falling edge. Data is shifted into the SDI pin on each possible. rising edge of SCK. 24702fb 6 For more information www.linear.com/LTC2470 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Analog Inputs Power Requirements Digital Inputs and Digital Outputs Timing Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Revision History Typical Application Related Parts