link to page 9 AD8420Data SheetParameter TestConditions/CommentsMinTypMaxUnit GAIN2 G = 1 + (R2/R1) Gain Range 1 1000 V/V Gain Error G = 1 VOUT = 0.1 V to 1.1 V, VREF = 0.1 V 0.02 % G = 10 to 1000 VOUT = 0.2 V to 4.8 V 0.05 0.1 % Gain vs. Temperature TA = −40°C to +85°C 10 ppm/°C OUTPUT Output Swing VS = 5 V, RL = 10 kΩ to midsupply VS = ±5 V, RL = 20 kΩ to ground TA = +25°C −VS + 0.1 +VS − 0.15 V TA = +85°C −VS + 0.1 +VS − 0.2 V TA = −40°C −VS + 0.1 +VS − 0.15 V Short-Circuit Current 10 mA POWER SUPPLY Operating Range Single-supply operation3 2.7 36 V Quiescent Current VS = 5 V TA = +25°C 55 70 90 μA TA = +85°C 110 μA TA = −40°C 75 μA TEMPERATURE RANGE Specified −40 +85 °C Operational4 −40 +125 °C 1 The input stage uses PNP transistors; therefore, input bias current always flows out of the device. 2 For G > 1, errors from External Resistor R1 and External Resistor R2 should be considered in addition to these specifications, including error from FB pin bias current. 3 Minimum supply voltage indicated for V+IN, V−IN, and VREF = 0 V. 4 See the Typical Performance Characteristics section for operation between 85°C and 125°C. Rev. A | Page 4 of 26 Document Outline FEATURES APPLICATIONS PIN CONFIGURATION GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION ARCHITECTURE SETTING THE GAIN GAIN ACCURACY INPUT VOLTAGE RANGE INPUT PROTECTION Input Voltages Beyond the Rails Large Differential Input Voltage LAYOUT Common-Mode Rejection Ratio over Frequency Power Supplies Reference DRIVING THE REFERENCE PIN INPUT BIAS CURRENT RETURN PATH RADIO FREQUENCY INTERFERENCE (RFI) OUTPUT BUFFERING APPLICATIONS INFORMATION AD8420 IN ELECTROCARDIOGRAPHY (ECG) CLASSIC BRIDGE CIRCUIT 4 mA TO 20 mA SINGLE-SUPPLY RECEIVER OUTLINE DIMENSIONS ORDERING GUIDE