Datasheet ADA4817-1, ADA4817-2 (Analog Devices) - 27
| Manufacturer | Analog Devices |
| Description | Dual, Low Noise, 1 GHz FastFET Op Amplifier |
| Pages / Page | 31 / 27 — Data Sheet. ADA4817-1. /ADA4817-2. HIGH SPEED JFET INPUT INSTRUMENTATION. … |
| Revision | G |
| File Format / Size | PDF / 632 Kb |
| Document Language | English |
Data Sheet. ADA4817-1. /ADA4817-2. HIGH SPEED JFET INPUT INSTRUMENTATION. AMPLIFIER. VCC. 0.1µF. 10µF. RS1. 350Ω. ADA4817-2 U1. VEE. RF = 500Ω
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Data Sheet ADA4817-1 /ADA4817-2 HIGH SPEED JFET INPUT INSTRUMENTATION
The system bandwidth for G = 1 is 400 MHz. For gains higher
AMPLIFIER
than 2, the bandwidth is set by the preamp, and it can be Figure 66 shows an example of a high speed instrumentation approximated by amplifier with a high input impedance using the ADA4817-1/ In-amp−3 dB = (fCR × RG)/(2 × RF) ADA4817-2. The dc transfer function is The match of resistor ratios, R1:R2 to R3:R4, primarily determine the common-mode rejection of the in-amp and it is estimated by V (V V ) 2R = − 1+ F (16) OUT N P G R V (δ1− δ2) O = (17) For G = 1, it is recommended that the feedback resistors for the CM V (1+ δ ) 1 δ2 two preamps be set to 0 Ω and the gain resistor be open. The summing junction impedance for the preamps is equal to RF | 0.5(RG). Keep this value relatively low to improve the bandwidth response like in the previous example.
VCC 0.1µF 10µF RS1 R2 V 350Ω N ADA4817-2 U1 VCC 0.1µF 10µF VEE 0.1µF 10µF R1 350Ω RF = 500Ω ADA4817-1 VO RG R3 RF = 500Ω 350Ω 0.1µF 10µF VCC R4 V 350Ω EE 0.1µF 10µF ADA4817-2 R U2 S2 0.1µF 10µF VP
050
VEE
07756- Figure 66. High Speed Instrumentation Amplifier Rev. G | Page 27 of 31 Document Outline FEATURES APPLICATIONS CONNECTION DIAGRAMS TABLE OF CONTENTS REVISION HISTORY GENERAL DESCRIPTION SPECIFICATIONS ±5 V OPERATION 5 V OPERATION ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE MAXIMUM SAFE POWER DISSIPATION ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TEST CIRCUITS THEORY OF OPERATION CLOSED-LOOP FREQUENCY RESPONSE NONINVERTING CLOSED-LOOP FREQUENCY RESPONSE INVERTING CLOSED-LOOP FREQUENCY RESPONSE WIDEBAND OPERATION DRIVING CAPACITIVE LOADS THERMAL CONSIDERATIONS POWER-DOWN OPERATION CAPACITIVE FEEDBACK HIGHER FREQUENCY ATTENUATION LAYOUT, GROUNDING, AND BYPASSING CONSIDERATIONS SIGNAL ROUTING POWER SUPPLY BYPASSING GROUNDING EXPOSED PAD LEAKAGE CURRENTS INPUT CAPACITANCE INPUT-TO-INPUT/OUTPUT COUPLING APPLICATIONS INFORMATION LOW DISTORTION PINOUT WIDEBAND PHOTODIODE PREAMP HIGH SPEED JFET INPUT INSTRUMENTATION AMPLIFIER ACTIVE LOW-PASS FILTER (LPF) OUTLINE DIMENSIONS ORDERING GUIDE
Data Sheet ADA4817-1 /ADA4817-2 HIGH SPEED JFET INPUT INSTRUMENTATION
The system bandwidth for G = 1 is 400 MHz. For gains higher
AMPLIFIER
than 2, the bandwidth is set by the preamp, and it can be Figure 66 shows an example of a high speed instrumentation approximated by amplifier with a high input impedance using the ADA4817-1/ In-amp−3 dB = (fCR × RG)/(2 × RF) ADA4817-2. The dc transfer function is The match of resistor ratios, R1:R2 to R3:R4, primarily determine the common-mode rejection of the in-amp and it is estimated by V (V V ) 2R = − 1+ F (16) OUT N P G R V (δ1− δ2) O = (17) For G = 1, it is recommended that the feedback resistors for the CM V (1+ δ ) 1 δ2 two preamps be set to 0 Ω and the gain resistor be open. The summing junction impedance for the preamps is equal to RF | 0.5(RG). Keep this value relatively low to improve the bandwidth response like in the previous example.
VCC 0.1µF 10µF RS1 R2 V 350Ω N ADA4817-2 U1 VCC 0.1µF 10µF VEE 0.1µF 10µF R1 350Ω RF = 500Ω ADA4817-1 VO RG R3 RF = 500Ω 350Ω 0.1µF 10µF VCC R4 V 350Ω EE 0.1µF 10µF ADA4817-2 R U2 S2 0.1µF 10µF VP
050
VEE
07756- Figure 66. High Speed Instrumentation Amplifier Rev. G | Page 27 of 31 Document Outline FEATURES APPLICATIONS CONNECTION DIAGRAMS TABLE OF CONTENTS REVISION HISTORY GENERAL DESCRIPTION SPECIFICATIONS ±5 V OPERATION 5 V OPERATION ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE MAXIMUM SAFE POWER DISSIPATION ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TEST CIRCUITS THEORY OF OPERATION CLOSED-LOOP FREQUENCY RESPONSE NONINVERTING CLOSED-LOOP FREQUENCY RESPONSE INVERTING CLOSED-LOOP FREQUENCY RESPONSE WIDEBAND OPERATION DRIVING CAPACITIVE LOADS THERMAL CONSIDERATIONS POWER-DOWN OPERATION CAPACITIVE FEEDBACK HIGHER FREQUENCY ATTENUATION LAYOUT, GROUNDING, AND BYPASSING CONSIDERATIONS SIGNAL ROUTING POWER SUPPLY BYPASSING GROUNDING EXPOSED PAD LEAKAGE CURRENTS INPUT CAPACITANCE INPUT-TO-INPUT/OUTPUT COUPLING APPLICATIONS INFORMATION LOW DISTORTION PINOUT WIDEBAND PHOTODIODE PREAMP HIGH SPEED JFET INPUT INSTRUMENTATION AMPLIFIER ACTIVE LOW-PASS FILTER (LPF) OUTLINE DIMENSIONS ORDERING GUIDE
