LTC2157-14/ LTC2156-14/LTC2155-14 INTERNAL REFERENCE CHARACTERISTICSThe l denotes the specifications which apply over thefull operating temperature range, otherwise specifications are at TA = 25°C. (Note 5)PARAMETERCONDITIONSMINTYPMAXUNITS VCM Output Voltage IOUT = 0 0.435 • 0.435 • 0.435 • V VDD – 18mV VDD VDD + 18mV VCM Output Temperature Drift ±37 ppm/°C VCM Output Resistance –1mA < IOUT < 1mA 4 Ω VREF Output Voltage IOUT = 0 1.225 1.250 1.275 V VREF Output Temperature Drift ±30 ppm/°C VREF Output Resistance –400µA < IOUT < 1mA 7 Ω VREF Line Regulation 1.7V < VDD < 1.9V 0.6 mV/V POWER REQUIREMENTSThe l denotes the specifications which apply over the full operating temperaturerange, otherwise specifications are at TA = 25°C. (Note 5)LTC2157-14LTC2156-14LTC2155-14SYMBOL PARAMETERCONDITIONSMINTYPMAXMINTYPMAXMINTYPMAXUNITS VDD Analog Supply Voltage (Note 9) l 1.7 1.8 1.9 1.7 1.8 1.9 1.7 1.8 1.9 V OVDD Output Supply Voltage (Note 9) l 1.7 1.8 1.9 1.7 1.8 1.9 1.7 1.8 1.9 V IVDD Analog Supply Current l 316 350 299 330 274 305 mA IOVDD Digital Supply Current 1.75mA LVDS Mode l 45 50 43 49 41 48 mA 3.5mA LVDS Mode l 76 85 73 84 71 83 mA PDISS Power Dissipation 1.75mA LVDS Mode l 650 720 616 682 567 635 mW 3.5mA LVDS Mode l 706 783 670 745 621 698 mW PSLEEP Sleep Mode Power Clock Disabled <5 <5 <5 mW Clocked at fS(MAX) <5 <5 <5 mW PNAP Nap Mode Power Clocked at fS(MAX) 213 198 184 mW DIGITAL INPUTS AND OUTPUTSThe l denotes the specifications which apply over the full operatingtemperature range, otherwise specifications are at TA = 25°C. (Note 5)SYMBOL PARAMETERCONDITIONSMINTYPMAXUNITSENCODE INPUTS (ENC+, ENC– ) VID Differential Input Voltage (Note 8) l 0.2 V VICM Common Mode Input Voltage Internally Set 1.2 V Externally Set (Note 8) l 1.1 1.5 V RIN Input Resistance (See Figure 2) 10 kΩ CIN Input Capacitance (Note 8) 2 pF DIGITAL INPUTS (CS, SDI, SCK) VIH High Level Input Voltage VDD = 1.8V l 1.3 V VIL Low Level Input Voltage VDD = 1.8V l 0.6 V IIN Input Current VIN = 0V to 3.6V l –10 10 µA CIN Input Capacitance (Note 8) 3 pF SDO OUTPUT (Open-Drain Output. Requires 2k Pull-Up Resistor if SDO Is Used) ROL Logic Low Output Resistance to GND VDD = 1.8V, SDO = 0V 200 Ω IOH Logic High Output Leakage Current SDO = 0V to 3.6V l –10 10 µA COUT Output Capacitance (Note 8) 4 pF 21576514fb 4 For more information www.linear.com/LTC2157-14 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Converter Characteristics Analog Input Dynamic Accuracy Internal Reference Characteristics Power Requirements Digital Inputs And Outputs Timing Characteristics Timing Diagrams Typical Performance Characteristics Pin Functions Functional Block Diagram Applications Information Package Description Related Parts