Datasheet AD7949 (Analog Devices) - 5

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Data Sheet AD7949 Parameter Test Conditions/Comments Min Typ Max Unit
INTERNAL REFERENCE REF Output Voltage 2.5 V, @ 25°C 2.490 2.500 2.510 V 4.096 V, @ 25°C 4.086 4.096 4.106 V REFIN Output Voltage7 2.5 V, @ 25°C 1.2 V 4.096 V, @ 25°C 2.3 V REF Output Current ±300 µA Temperature Drift ±10 ppm/°C Line Regulation VDD = 5 V ± 5% ±15 ppm/V Long-Term Drift 1000 hours 50 ppm Turn-On Settling Time CREF = 10 µF 5 ms EXTERNAL REFERENCE Voltage Range REF input 0.5 VDD + 0.3 V REFIN input (buffered) 0.5 VDD − 0.5 V Current Drain 250 kSPS, REF = 5 V 50 µA TEMPERATURE SENSOR Output Voltage8 @ 25°C 283 mV Temperature Sensitivity 1 mV/°C DIGITAL INPUTS Logic Levels VIL −0.3 +0.3 × VIO V VIH 0.7 × VIO VIO + 0.3 V IIL −1 +1 µA IIH −1 +1 µA DIGITAL OUTPUTS Data Format9 Pipeline Delay10 VOL ISINK = +500 µA 0.4 V VOH ISOURCE = −500 µA VIO − 0.3 V POWER SUPPLIES VDD Specified performance 2.3 5.5 V VIO Specified performance 2.3 VDD + 0.3 V Operating range 1.8 VDD + 0.3 V Standby Current11, 12 VDD and VIO = 5 V, @ 25°C 50 nA Power Dissipation VDD = 2.5 V, 100 SPS throughput 1.5 µW VDD = 2.5 V, 100 kSPS throughput 1.45 2.0 mW VDD = 2.5 V, 200 kSPS throughput 2.9 4.0 mW VDD = 5 V, 250 kSPS throughput 10.8 12.5 mW VDD = 5 V, 250 kSPS throughput with internal 13.5 15.5 mW reference Energy per Conversion 50 nJ TEMPERATURE RANGE13 Specified Performance TMIN to TMAX −40 +85 °C 1 See the Analog Inputs section. 2 The bandwidth is set in the configuration register. 3 LSB means least significant bit. With the 5 V input range, one LSB = 305 µV. 4 See the Terminology section. These specifications include full temperature range variation but not the error contribution from the external reference. 5 With VDD = 5 V, unless otherwise noted. 6 All specifications expressed in decibels are referred to a full-scale input FSR and tested with an input signal at 0.5 dB below ful scale, unless otherwise specified. 7 This is the output from the internal band gap. 8 The output voltage is internal and present on a dedicated multiplexer input. 9 Unipolar mode: serial 14-bit straight binary. Bipolar mode: serial 14-bit twos complement. 10 Conversion results available immediately after completed conversion. 11 With all digital inputs forced to VIO or GND as required. 12 During acquisition phase. 13 Contact an Analog Devices, Inc., sales representative for the extended temperature range. Rev. F | Page 5 of 32 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY THEORY OF OPERATION OVERVIEW CONVERTER OPERATION TRANSFER FUNCTIONS TYPICAL CONNECTION DIAGRAMS Unipolar or Bipolar Bipolar Single Supply ANALOG INPUTS Input Structure Selectable Low-Pass Filter Input Configurations Sequencer Source Resistance DRIVER AMPLIFIER CHOICE VOLTAGE REFERENCE OUTPUT/INPUT Internal Reference/Temperature Sensor External Reference and Internal Buffer External Reference Reference Decoupling POWER SUPPLY SUPPLYING THE ADC FROM THE REFERENCE DIGITAL INTERFACE READING/WRITING DURING CONVERSION, FAST HOSTS READING/WRITING AFTER CONVERSION, ANY SPEED HOSTS READING/WRITING SPANNING CONVERSION, ANY SPEED HOST CONFIGURATION REGISTER, CFG GENERAL TIMING WITHOUT A BUSY INDICATOR GENERAL TIMING WITH A BUSY INDICATOR CHANNEL SEQUENCER Examples READ/WRITE SPANNING CONVERSION WITHOUT A BUSY INDICATOR READ/WRITE SPANNING CONVERSION WITH A BUSY INDICATOR APPLICATION HINTS LAYOUT EVALUATING AD7949 PERFORMANCE OUTLINE DIMENSIONS ORDERING GUIDE