ADA4938-1/ADA4938-2Data SheetPIN CONFIGURATIONS AND FUNCTION DESCRIPTIONSSSSS11T–V–V–V–V111BSS1UN6IFVVDO1514131+–––P–432102222921–FB 112 PD–IN1 118 +OUT1+IN 211 –OUTADA4938-1+FB1 217 VOCM1–IN 3TOP VIEW10 +OUT+V3ADA4938-216S1–VS2(Not to Scale)+V4TOP VIEW15 –V+FB 49VS1S2OCM(Not to Scale)–FB2 514 PD25678+IN2 613 –OUT2SSSS+V+V+V+V78901 11 212222NOTES22NBSSMT1. THE EXPOSED PAD IS NOT ELECTRICALLY CONNECTEDI– F V VCU+++OTO THE DEVICE. IT IS TYPICALLY SOLDERED TO GROUND 03 O 0 V+OR A POWER PLANE ON THE PCB THAT IS THERMALLY 2- CONDUCTIVE. 659 NOTES 0 1. THE EXPOSED PAD IS NOT ELECTRICALLY CONNECTED 06 TO THE DEVICE. IT IS TYPICALLY SOLDERED TO GROUND 22- OR A POWER PLANE ON THE PCB THAT IS THERMALLY 659 CONDUCTIVE. 0 Figure 5. ADA4938-1 Pin Configuration Figure 6. ADA4938-2 Pin Configuration Table 7. ADA4938-1 Pin Function DescriptionsTable 8. ADA4938-2 Pin Function DescriptionsPin No.MnemonicDescriptionPin No.MnemonicDescription 1 −FB Negative Output Feedback Pin. 1 −IN1 Negative Input Summing Node 1. 2 +IN Positive Input Summing Node. 2 +FB1 Positive Output Feedback Pin 1. 3 −IN Negative Input Summing Node. 3, 4 +VS1 Positive Supply Voltage 1. 4 +FB Positive Output Feedback Pin. 5 −FB2 Negative Output Feedback Pin 2. 5 to 8 +VS Positive Supply Voltage. 6 +IN2 Positive Input Summing Node 2. 9 VOCM Output Common-Mode Voltage. 7 −IN2 Negative Input Summing Node 2. 10 +OUT Positive Output for Load Connection. 8 +FB2 Positive Output Feedback Pin 2. 11 −OUT Negative Output for Load Connection. 9, 10 +VS2 Positive Supply Voltage 2. 12 PD Power-Down Pin. 11 VOCM2 Output Common-Mode Voltage 2. 13 to 16 −VS Negative Supply Voltage. 12 +OUT2 Positive Output 2. EP Exposed Paddle. The exposed pad is not 13 −OUT2 Negative Output 2. electrically connected to the device. It is 14 PD2 Power-Down Pin 2. typically soldered to ground or a power plane on the PCB that is 15, 16 −VS2 Negative Supply Voltage 2. thermally conductive. 17 VOCM1 Output Common-Mode Voltage 1. 18 +OUT1 Positive Output 1. 19 −OUT1 Negative Output 1. 20 PD1 Power-Down Pin 1. 21, 22 −VS1 Negative Supply Voltage 1. 23 −FB1 Negative Output Feedback Pin 1. 24 +IN1 Positive Input Summing Node 1. EP Exposed Paddle. The exposed pad is not electrically connected to the device. It is typically soldered to ground or a power plane on the PCB that is thermally conductive. Rev. B | Page 8 of 26 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAMS REVISION HISTORY SPECIFICATIONS DUAL-SUPPLY OPERATION ±DIN to ±OUT Performance VOCM to ±OUT Performance SINGLE-SUPPLY OPERATION ±DIN to ±OUT Performance VOCM to ±OUT Performance ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Maximum Power Dissipation ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TEST CIRCUTS TERMINOLOGY THEORY OF OPERATION ANALYZING AN APPLICATION CIRCUIT SETTING THE CLOSED-LOOP GAIN ESTIMATING THE OUTPUT NOISE VOLTAGE THE IMPACT OF MISMATCHES IN THE FEEDBACK NETWORKS CALCULATING THE INPUT IMPEDANCE OF AN APPLICATION CIRCUIT INPUT COMMON-MODE VOLTAGE RANGE IN SINGLE-SUPPLY APPLICATIONS TERMINATING A SINGLE-ENDED INPUT SETTING THE OUTPUT COMMON-MODE VOLTAGE LAYOUT, GROUNDING, AND BYPASSING HIGH PERFORMANCE ADC DRIVING OUTLINE DIMENSIONS ORDERING GUIDE