Datasheet ADUCM355 (Analog Devices) - 22

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ADuCM355 Data Sheet Pin No. Mnemonic Type1 Description
Sensor Channel 1 Pins B11 CE1 AI/O Output of Potentiostat 1 Amplifier. This pin is connected to a counter electrode when measuring electrochemical sensors. Optionally, this pin can be used as an ADC input. If unused, it is recommended to connect this pin to AVDD_REG or AGND. A11 RE1 AI Input to Analog Input Switch Matrix. For electrochemical sensor measurement, connect this pin to the Potentiostat 1 amplifier inverting input. Optionally, this pin can be used as an ADC input. If unused, it is recommended to connect this pin to AVDD_REG or AGND. A9 SE1 AI Input to Analog Switch Matrix. For electrochemical sensor measurement, connect this pin to TIA, inverting input. If unused, it is recommended to connect this pin to AVDD_REG or AGND. A10 DE1 AI Diagnostic Electrode Input 1. This pin is internally connected to the analog input switch matrix. If unused, it is recommended to connect this pin to AVDD_REG or AGND. C10 VBIAS1 AI/O VBIAS1 to DAC1 Output. This pin is used internally to set the common-mode voltage of the Potentiostat 1 amplifier. Connect this pin to AGND via a 100 nF capacitor. Optionally, this pin can be used as an ADC input. If unused, it is recommended to connect this pin to AVDD_REG or AGND. Do not use this pin as a voltage source for an external circuit. B10 VZERO1 AI/O VZERO1 to DAC1 Output. This pin is used internally to set the common-mode voltage of TIA1. Optionally, this pin can be used as an ADC input. If unused, it is recommended to connect this pin to AVDD_REG or AGND. Do not use this pin as a voltage source for an external circuit. D11 RC1_0 AI Connection to External Capacitor for Low Power TIA Input. Connect this pin to the other side of the capacitor to RC1_1. Use a 100 nF capacitor with this pin. Optionally, a TIA gain resistor can be connected across RC1_0 and RC1_1. D10 RC1_1 AI Connection to External Capacitor for Low Power TIA Input. Connect this pin to the other side of the capacitor to RC1_0. Use a 100 nF capacitor with this pin. Optionally, a TIA gain resistor can be connected across RC1_0 and RC1_1. C11 CAP_POT1 AI High Frequency Filter Capacitor. Connect this pin to CE1 pin via an external capacitor of 100 nF. This pin is used for the RC filter on the RE1 input. Other Analog Pins A7 RCAL0 AI Calibration Resistor Connection. This pin is the connected to the excitation amplifier output. This pin is used for the calibration of impedance measurement circuitry. A6 RCAL1 AI Calibration Resistor Connection. This pin is connected to the high power TIAs, inverting input. This pin is used for the calibration of impedance measurement circuitry. B9 AIN0 AI ADC Input. B8 AIN1 AI ADC Input. B6 AIN2 AI ADC Input. B7 AIN3/BUF_VREF1V8 AI/O ADC Input (AIN3)/Buffered 1.8 V Bias (BUF_VREF1V8). The maximum load = 200 μA. Connect BUF_VREF1V8 to AGND via a 100 pF capacitor. A4 AIN4_LPF0 AI/O External Low-Pass Filter. This pin is required for TIA0 when measuring electrochemical sensors. A 4.7 μF capacitor is recommended when this pin is used as the low-pass filter capacitor connection. Optionally, this pin can be used as an ADC input. B4 AIN5 AI ADC Input. B3 AIN6 AI ADC Input. A8 AIN7_LPF1 AI/O External Low-Pass Filter. This pin is required for TIA1 when measuring electrochemical sensors. A 4.7 μF capacitor is recommended when this pin is used as the low-pass filter capacitor connection. Optionally, this pin can be used as an ADC input. A5 VREF_1.82V AI/O Decoupling Capacitor Connection for 1.8 V Internal Reference. Connect a 4.7 μF capacitor between this pin and AGND. Do not use this pin as a voltage source for an external circuit. E2 VREF_2.5V AI/O Decoupling Capacitor Connection for 2.5 V Internal Reference. Connect a 470 nF capacitor between this pin and AGND. Do not use this pin as a voltage source for an external circuit. E11 ADCVBIAS_CAP AI/O Decoupling Capacitor for PGA Common Mode Reference. Connect a 470 nF capacitor between this pin and AGND. Do not use this pin as a voltage source for an external circuit. B5 AGND_REF S Reference Ground Pin. Connect this pin to AGND. Rev. C | Page 22 of 28 Document Outline FEATURES APPLICATIONS SIMPLIFIED FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION SPECIFICATIONS MICROCONTROLLER ELECTRICAL SPECIFICATIONS RMS NOISE RESOLUTION OF ADC TIMING SPECIFICATIONS Timing Diagrams ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS APPLICATIONS INFORMATION RECOMMENDED CIRCUIT AND COMPONENT VALUES OUTLINE DIMENSIONS ORDERING GUIDE