Ultralow Noise VGAs with Preamplifier and Programmable RIN AD8331/AD8332/AD8334 Data Sheet FEATURES FUNCTIONAL BLOCK DIAGRAM Ultrasound and sonar time-gain controls High performance automatic gain control (AGC) systems I/Q signal processing High speed, dual ADC drivers The AD8331/AD8332/AD8334 are single-, dual-, and quadchannel, ultralow noise linear-in-dB, variable gain amplifiers (VGAs). Optimized for ultrasound systems, they are usable as a low noise variable gain element at frequencies up to 120 MHz. Included in each channel are an ultralow noise preamp (LNA), an X-AMP® VGA with 48 dB of gain range, and a selectable gain postamp with adjustable output limiting. The LNA gain is 19 dB with a single-ended input and differential outputs. Using a single resistor, the LNA input impedance can be adjusted to match a signal source without compromising noise performance. The 48 dB gain range of the VGA makes these devices suitable for a variety of applications. Excellent bandwidth uniformity is maintained across the entire range. The gain control interface provides precise linear-in-dB scaling of 50 dB/V for control voltages between 40 mV and 1 V. Factory trim ensures excellent part-to-part and channel-to-channel gain matching. Rev. I HILO 3.5dB OR 15.5dB VMID VOH – 48dB ATTENUATOR + 19dB INH LMD VCM BIAS VGA BIAS AND INTERPOLATOR 21dB PA VOL GAIN CONTROL INTERFACE CLAMP RCLMP ENB 03199-001 AD8331/AD8332/AD8334 GAIN Figure 1. Signal Path Block Diagram 60 VGAIN = 1V 50 HI GAIN MODE VGAIN = 0.8V 40 VGAIN = 0.6V 30 VGAIN = 0.4V 20 VGAIN = 0.2V VGAIN = 0V 10 0 –10 100k GENERAL DESCRIPTION VCM 03199-002 APPLICATIONS VIN LNA GAIN (dB) Ultralow noise preamplifier (preamp) Voltage noise = 0.74 nV/√Hz Current noise = 2.5 pA/√Hz 3 dB bandwidth AD8331: 120 MHz AD8332, AD8334: 100 MHz Low power AD8331: 125 mW/channel AD8332, AD8334: 145 mW/channel Wide gain range with programmable postamp −4.5 dB to +43.5 dB in LO gain mode 7.5 dB to 55.5 dB in HI gain mode Low output-referred noise: 48 nV/√Hz typical Active input impedance matching Optimized for 10-bit/12-bit ADCs Selectable output clamping level Single 5 V supply operation AD8332 and AD8334 available in lead frame chip scale package LON LOP VIP 1M 10M 100M 1G FREQUENCY (Hz) Figure 2. Frequency Response vs. Gain Differential signal paths result in superb second- and thirdorder distortion performance and low crosstalk. The low output-referred noise of the VGA is advantageous in driving high speed differential ADCs. The gain of the postamp can be pin selected to 3.5 dB or 15.5 dB to optimize gain range and output noise for 12-bit or 10-bit converter applications. The output can be limited to a user-selected clamping level, preventing input overload to a subsequent ADC. An external resistor adjusts the clamping level. The operating temperature range is −40°C to +85°C. The AD8331 is available in a 20-lead QSOP package, the AD8332 is available in 28-lead TSSOP and 32-lead LFCSP packages, and the AD8334 is available in a 64-lead LFCSP package. Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 ©2003–2016 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com AD8331/AD8332/AD8334 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Ultrasound TGC Application ................................................... 34 Applications ....................................................................................... 1 High Density Quad Layout ....................................................... 34 General Description ......................................................................... 1 AD8331 Evaluation Board ............................................................ 39 Functional Block Diagram .............................................................. 1 General Description ................................................................... 39 Revision History ............................................................................... 2 User-Supplied Optional Components ..................................... 39 Specifications..................................................................................... 4 Measurement Setup.................................................................... 39 Absolute Maximum Ratings ............................................................ 7 Board Layout ............................................................................... 39 ESD Caution .................................................................................. 7 AD8331 Evaluation Board Schematics .................................... 40 Pin Configurations and Function Descriptions ........................... 8 AD8331 Evaluation Board PCB Layers ................................... 42 Typical Performance Characteristics ........................................... 12 AD8332 Evaluation Board ............................................................ 43 Test Circuits ..................................................................................... 20 General Description ................................................................... 43 Measurement Considerations ................................................... 20 User-Supplied Optional Components ..................................... 43 Theory of Operation ...................................................................... 24 Measurement Setup.................................................................... 43 Overview...................................................................................... 24 Board Layout ............................................................................... 43 Low Noise Amplifier (LNA) ..................................................... 25 Evaluation Board Schematics ................................................... 44 Variable Gain Amplifier ............................................................ 27 AD8332 Evaluation Board PCB Layers ................................... 46 Postamplifier ............................................................................... 28 AD8334 Evaluation Board ............................................................ 47 Applications Information .............................................................. 30 General Description ................................................................... 47 LNA—External Components .................................................... 30 Configuring the Input Impedance ........................................... 48 Driving ADCs ............................................................................. 32 Measurement Setup.................................................................... 48 Overload ...................................................................................... 32 Board Layout ............................................................................... 48 Optional Input Overload Protection ....................................... 32 Evaluation Board Schematics ................................................... 49 Layout, Grounding, and Bypassing .......................................... 33 AD8334 Evaluation Board PCB Layers ................................... 51 Multiple Input Matching ........................................................... 33 Outline Dimensions ....................................................................... 53 Disabling the LNA ...................................................................... 33 Ordering Guide .......................................................................... 55 REVISION HISTORY 5/2016—Rev. H to Rev. I Changes to Figure 5, and Table 5 .................................................... 9 Updated Outline Dimensions ....................................................... 54 Changes to Ordering Guide .......................................................... 55 3/2015—Rev. G to Rev. H Changes to Pin 29 Description; Table 6 ....................................... 11 Updated Figure 123, Figure 124, Figure 125; Outline Dimensions ...................................................................................... 53 Changes to Ordering Guide .......................................................... 55 10/2010—Rev. F to Rev. G Changes to Quiescent Current per Channel Parameter, Table 1 ................................................................................................ 6 Changes to Pin 1, Table 3 ................................................................. 8 Changes to Pin 1 and Pin 28, Table 4 and Pin 4 and Pin 5, Table 5 ................................................................................................ 9 Changes to Figure 6 and Table 6................................................... 10 Changes to Figure 33...................................................................... 16 Changes to Figure 64...................................................................... 22 Changes to Figure 70...................................................................... 24 Changes to Low Noise Amplifier (LNA) Section and Figure 74 .......................................................................................... 25 Changes to Figure 94...................................................................... 38 Changes to General Descriptions Section, Figure 95 Caption, Table 10, and Board Layout Section............................................. 39 Changes to Figure 96...................................................................... 40 Changes to Figure 97...................................................................... 41 Changes to Figure 98 and Figure 103 .......................................... 42 Deleted AD8331 Bill of Materials Section and Table 11; Renumbered Sequentially ............................................................. 43 Changes to Figure 104 ................................................................... 43 Changes to Figure 106 ................................................................... 45 Changes to Figure 107 ................................................................... 46 Rev. I | Page 2 of 55 Data Sheet AD8331/AD8332/AD8334 Changes to Figure 113 ....................................................................47 Changes to Figure 114 and Board Layout Section ......................48 Deleted AD8332 Bill of Materials Section and Table 13; Renumbered Sequentially ..............................................................48 Changes to Figure 115 ....................................................................49 Changes to Figure 116 ....................................................................50 Changes to Figure 117 to Figure 120 ............................................51 Changes to Figure 121 ....................................................................52 Deleted AD8334 Bill of Materials Section and Table 15; Renumbered Sequentially ..............................................................54 4/2008—Rev. E to Rev. F Changed RFB to RIZ Throughout...................................................... 4 Changes to Figure 1........................................................................... 1 Changes to Table 1, LNA and VGA Characteristics, Output Offset Voltage, Conditions ............................................................... 4 Changes to Quiescent Current per Channel and Power Down Current Parameters ........................................................................... 6 Changes to Table 2 ............................................................................ 7 Changes to Table 3, Pin 1 Description............................................ 8 Changes to Table 4, Pin 1 and Pin 28 Descriptions ...................... 9 Changes to Table 5, Pin 4 and Pin 5 Descriptions ........................ 9 Changes to Table 6, Pin 2, Pin 15, and Pin 20 Descriptions ......10 Changes to Table 6, Pin 61 Description .......................................11 Changes to Typical Performance Characteristics Section, Default Conditions ..........................................................................12 Changes to Figure 25 ......................................................................15 Changes to Figure 39 ......................................................................17 Changes to Figure 55 Through Figure 68 ...................................20 Changes to Theory of Operation, Overview Section .................24 Changes to Low Noise Amplifier Section and Figure 74 ...........25 Changes to Active Impedance Matching Section, Figure 75, and Figure 77 ...................................................................................26 Changes to Figure 78 ......................................................................27 Changes to Equation 6, Table 7, Figure 81, and Figure 82.........30 Changes to Figure 83 ......................................................................31 Changes to Figure 88 ......................................................................32 Switched Figure 89 and Figure 90 .................................................33 Changes to Figure 89 ......................................................................33 Changes to Ultrasound TGC Application Section .....................34 Incorporated AD8331-EVAL Data Sheet, Rev. A .......................39 Changes to User-Supplied Optional Components Section and Measurement Setup Section ...................................................39 Changes to Figure 95 ......................................................................39 Changes to Figure 97 ......................................................................41 Added Figure 98 ..............................................................................42 Incorporated AD8332-EVALZ Data Sheet, Rev. D.....................44 Incorporated AD8334-EVAL Data Sheet, Rev. 0 ........................49 Updated Outline Dimensions ........................................................55 Changes to Ordering Guide ...........................................................57 4/2006—Rev. D to Rev. E Added AD8334 ................................................................... Universal Changes to Figure 1 and Figure 2.................................................... 1 Changes to Table 1 ............................................................................ 4 Changes to Table 2 ............................................................................ 7 Changes to Figure 7 through Figure 9 and Figure 12................. 12 Changes to Figure 13, Figure 14, Figure 16, and Figure 18 ....... 13 Changes to Figure 23 and Figure 24 ............................................. 14 Changes to Figure 25 through Figure 27...................................... 15 Changes to Figure 31 and Figure 33 through Figure 36 ............ 16 Changes to Figure 37 through Figure 42...................................... 17 Changes to Figure 43, Figure 44, and Figure 48 .......................... 18 Changes to Figure 49, Figure 50, and Figure 54 .......................... 19 Inserted Figure 56 and Figure 57 .................................................. 20 Inserted Figure 58, Figure 59, and Figure 61 ............................... 21 Changes to Figure 60 ...................................................................... 21 Inserted Figure 63 and Figure 65 .................................................. 22 Changes to Figure 64 ...................................................................... 22 Moved Measurement Considerations Section ............................ 23 Inserted Figure 67 and Figure 68 .................................................. 23 Inserted Figure 70 and Figure 71 .................................................. 24 Change to Figure 72 ........................................................................ 24 Changes to Figure 73 and Low Noise Amplifier Section ........... 25 Changes to Postamplifier Section ................................................. 28 Changes to Figure 80 ...................................................................... 29 Changes to LNA—External Components Section ...................... 30 Changes to Logic Inputs—ENB, MODE, and HILO Section ... 31 Changes to Output Decoupling and Overload Sections ............ 32 Changes to Layout, Grounding, and Bypassing Section ............ 33 Changes to Ultrasound TGC Application Section ..................... 34 Added High Density Quad Layout Section ................................. 34 Inserted Figure 94 ........................................................................... 38 Updated Outline Dimensions........................................................ 39 Changes to Ordering Guide ........................................................... 40 3/2006—Rev. C to Rev. D Updated Format ................................................................. Universal Changes to Features and General Description .............................. 1 Changes to Table 1 ............................................................................ 3 Changes to Table 2 ............................................................................ 6 Changes to Ordering Guide ........................................................... 34 11/2003—Rev. B to Rev. C Addition of New Part ......................................................... Universal Changes to Figures ............................................................. Universal Updated Outline Dimensions........................................................ 32 5/2003—Rev. A to Rev. B Edits to Ordering Guide ................................................................. 32 Edits to Ultrasound TGC Application Section ........................... 25 Added Figure 71, Figure 72, and Figure 73.................................. 26 Updated Outline Dimensions........................................................ 31 2/2003—Rev. 0 to Rev. A Edits to Ordering Guide ................................................................. 32 Rev. I | Page 3 of 55 AD8331/AD8332/AD8334 Data Sheet SPECIFICATIONS TA = 25°C, VS = 5 V, RL = 500 Ω, RS = RIN = 50 Ω, RIZ = 280 Ω, CSH = 22 pF, f = 10 MHz, RCLMP = ∞, CL = 1 pF, VCM pin floating, −4.5 dB to +43.5 dB gain (HILO = LO), and differential output voltage, unless otherwise specified. Table 1. Parameter LNA CHARACTERISTICS Gain Input Voltage Range Input Resistance Input Capacitance Output Impedance −3 dB Small Signal Bandwidth Slew Rate Input Voltage Noise Input Current Noise Noise Figure Active Termination Match Unterminated Harmonic Distortion at LOP1 or LOP2 HD2 HD3 Output Short-Circuit Current LNA AND VGA CHARACTERISTICS −3 dB Small Signal Bandwidth AD8331 AD8332, AD8334 −3 dB Large Signal Bandwidth AD8331 AD8332, AD8334 Slew Rate AD8331 AD8332, AD8334 Input Voltage Noise Noise Figure Active Termination Match Unterminated Output-Referred Noise AD8331 AD8332, AD8334 Output Impedance, Postamplifier Output Signal Range, Postamplifier Test Conditions/Comments Single-ended input to differential output Input to output (single-ended) AC-coupled RIZ = 280 Ω RIZ = 412 Ω RIZ = 562 Ω RIZ = 1.13 kΩ RIZ = ∞ Single-ended, either output VOUT = 0.2 V p-p RS = 0 Ω, HI or LO gain, RIZ = ∞, f = 5 MHz RIZ = ∞, HI or LO gain, f = 5 MHz f = 10 MHz, LOP output RS = RIN = 50 Ω RS = 50 Ω, RIZ = ∞ VOUT = 0.5 V p-p, single-ended, f = 10 MHz Pin LON, Pin LOP Min Typ Max Unit 1 19 13 ±275 50 75 100 200 6 13 5 130 650 0.74 2.5 dB dB mV Ω Ω Ω Ω kΩ pF Ω MHz V/µs nV/√Hz pA/√Hz 3.7 2.5 dB dB −56 −70 165 dBc dBc mA 120 100 MHz MHz 110 90 MHz MHz VOUT = 0.2 V p-p VOUT = 2 V p-p LO gain HI gain LO gain HI gain RS = 0 Ω, HI or LO gain, RIZ = ∞, f = 5 MHz VGAIN = 1.0 V RS = RIN = 50 Ω, f = 10 MHz, measured RS = RIN = 200 Ω, f = 5 MHz, simulated RS = 50 Ω, RIZ = ∞, f = 10 MHz, measured RS = 200 Ω, RIZ = ∞, f = 5 MHz, simulated 300 1200 275 1100 0.82 V/µs V/µs V/µs V/µs nV/√Hz 4.15 2.0 2.5 1.0 dB dB dB dB VGAIN = 0.5 V, LO gain VGAIN = 0.5 V, HI gain VGAIN = 0.5 V, LO gain VGAIN = 0.5 V, HI gain DC to 1 MHz RL ≥ 500 Ω, unclamped, either pin 48 178 40 150 1 VCM ± 1.125 nV/√Hz nV/√Hz nV/√Hz nV/√Hz Ω V Rev. I | Page 4 of 55 Data Sheet Parameter Differential Output Offset Voltage AD8331 AD8332, AD8334 Output Short-Circuit Current Harmonic Distortion AD8331 HD2 HD3 HD2 HD3 AD8332, AD8334 HD2 HD3 HD2 HD3 Input 1 dB Compression Point Two-Tone Intermodulation Distortion (IMD3) AD8331 AD8332, AD8334 Output Third-Order Intercept AD8331 AD8332, AD8334 Channel-to-Channel Crosstalk (AD8332, AD8334) Overload Recovery Group Delay Variation ACCURACY Absolute Gain Error 2 Gain Law Conformance 3 Channel-to-Channel Gain Matching GAIN CONTROL INTERFACE (Pin GAIN) Gain Scaling Factor Gain Range Input Voltage (VGAIN) Range Input Impedance Response Time COMMON-MODE INTERFACE (PIN VCMx) Input Resistance 4 Output CM Offset Voltage Voltage Range AD8331/AD8332/AD8334 Test Conditions/Comments Min Typ 4.5 Max Unit 1 V p-p Differential, VGAIN = 0.5 V Common mode Differential, 0.05 V ≤ VGAIN ≤ 1.0 V Common mode −50 −125 −20 −125 ±5 −25 ±5 –25 45 +50 +100 +20 +100 mV mV mV mV mA VGAIN = 0.5 V, VOUT = 1 V p-p, HI gain f = 1 MHz −88 −85 −68 −65 dBc dBc dBc dBc VGAIN = 0.25 V, VOUT = 1 V p-p, f = 1 MHz to 10 MHz −82 −85 −62 −66 1 dBc dBc dBc dBc dBm VGAIN = 0.72 V, VOUT = 1 V p-p, f = 1 MHz VGAIN = 0.5 V, VOUT = 1 V p-p, f = 10 MHz VGAIN = 0.72 V, VOUT = 1 V p-p, f = 1 MHz VGAIN = 0.5 V, VOUT = 1 V p-p, f = 10 MHz −80 −72 −78 −74 dBc dBc dBc dBc VGAIN = 0.5 V, VOUT = 1 V p-p, f = 1 MHz VGAIN = 0.5 V, VOUT = 1 V p-p, f = 10 MHz VGAIN = 0.5 V, VOUT = 1 V p-p, f = 1 MHz VGAIN = 0.5 V, VOUT = 1 V p-p, f = 10 MHz VGAIN = 0.5 V, VOUT = 1 V p-p, f = 1 MHz 38 33 35 32 −98 dBm dBm dBm dBm dB VGAIN = 1.0 V, VIN = 50 mV p-p/1 V p-p, f = 10 MHz 5 MHz < f < 50 MHz, full gain range 5 ±2 ns ns f = 10 MHz f = 1 MHz f = 10 MHz 0.05 V < VGAIN < 0.10 V 0.10 V < VGAIN < 0.95 V 0.95 V < VGAIN < 1.0 V 0.1 V < VGAIN < 0.95 V 0.1 V < VGAIN < 0.95 V −1 −1 −2 +0.5 ±0.3 −1 ±0.2 ±0.1 +2 +1 +1 dB dB dB dB dB 0.10 V < VGAIN < 0.95 V LO gain HI gain 48.5 50 −4.5 to +43.5 7.5 to 55.5 0 to 1.0 10 500 51.5 dB/V dB dB V MΩ ns 48 dB gain change to 90% full scale Current limited to ±1 mA VCM = 2.5 V VOUT = 2.0 V p-p Rev. I | Page 5 of 55 −125 30 −25 1.5 to 3.5 +100 Ω mV V AD8331/AD8332/AD8334 Parameter ENABLE INTERFACE (PIN ENB, PIN ENBL, PIN ENBV) Logic Level to Enable Power Logic Level to Disable Power Input Resistance Power-Up Response Time HILO GAIN RANGE INTERFACE (PIN HILO) Logic Level to Select HI Gain Range Logic Level to Select LO Gain Range Input Resistance OUTPUT CLAMP INTERFACE (PIN RCLMP; HI OR LO GAIN) Accuracy HILO = LO HILO = HI MODE INTERFACE (PIN MODE) Logic Level for Positive Gain Slope Logic Level for Negative Gain Slope Input Resistance POWER SUPPLY (PIN VPS1, PIN VPS2, PIN VPSV, PIN VPSL, PIN VPOS) Supply Voltage Quiescent Current per Channel AD8331 AD8332 AD8334 Power Dissipation per Channel AD8331 AD8332, AD8334 Power-Down Current AD8331 AD8332 AD8334 LNA Current AD8331 (ENBL) AD8332, AD8334 (ENBL) VGA Current AD8331 (ENBV) AD8332, AD8334 (ENBV) PSRR Data Sheet Test Conditions/Comments Min Typ Max Unit 1 5 1.0 V V kΩ kΩ kΩ µs ms 5 1.0 50 V V kΩ ±50 ±75 mV mV 2.25 0 Pin ENB Pin ENBL Pin ENBV VINH = 30 mV p-p VINH = 150 mV p-p 25 40 70 300 4 2.25 0 RCLMP = 2.74 kΩ, VOUT = 1 V p-p (clamped) RCLMP = 2.21 kΩ, VOUT = 1 V p-p (clamped) 0 2.25 1.0 5 V V kΩ V 200 4.5 5.0 5.5 20 22 24 25 27.5 29.5 32 34 mA mA No signal 125 138 mW mW VGA and LNA disabled Each channel Each channel VGAIN = 0 V, f = 100 kHz All dBm values are referred to 50 Ω. The absolute gain refers to the theoretical gain expression in Equation 1. 3 Best-fit to linear-in-dB curve. 4 The current is limited to ±1 mA typical. 1 2 Rev. I | Page 6 of 55 50 50 50 240 300 600 400 600 1200 µA µA µA 7.5 7.5 11 12 15 15 mA mA 7.5 7.5 14 17 −68 20 20 mA mA dB Data Sheet AD8331/AD8332/AD8334 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter Voltage Supply Voltage (VPSn, VPSV, VPSL, VPOS) Input Voltage (INHx) ENB, ENBL, ENBV, HILO Voltage GAIN Voltage Power Dissipation RU Package 1 (AD8332) CP-32 Package (AD8332) RQ Package1 (AD8331) CP-64 Package (AD8334) Temperature Operating Temperature Range Storage Temperature Range Lead Temperature (Soldering 60 sec) θJA RU Package1 (AD8332) CP-32 Package2 2 (AD8332) RQ Package1 (AD8331) CP-64 Package 3 (AD8334) Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability. Rating 5.5 V VS + 200 mV VS + 200 mV 2.5 V ESD CAUTION 0.96 W 1.97 W 0.78 W 0.91 W −40°C to +85°C −65°C to +150°C 300°C 68°C/W 33°C/W 83°C/W 24.2°C/W 4-layer JEDEC board (2S2P). Exposed pad soldered to board, nine thermal vias in pad—JEDEC, 4-layer board J-STD-51-9. 3 Exposed pad soldered to board, 25 thermal vias in pad—JEDEC, 4-layer board J-STD-51-9. 1 2 Rev. I | Page 7 of 55 AD8331/AD8332/AD8334 Data Sheet PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS 20 COMM LMD 1 INH 2 VPSL 3 LON 4 LOP 5 COML 6 VIP 7 14 VPOS VIN 8 13 HILO MODE 9 12 RCLMP PIN 1 INDICATOR 19 ENBL 18 ENBV 16 VOL TOP VIEW (Not to Scale) 15 VOH 11 VCM GAIN 10 03199-003 17 COMM AD8331 Figure 3. 20-Lead QSOP Pin Configuration (AD8331) Table 3. 20-Lead QSOP Pin Function Description (AD8331) Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Mnemonic LMD INH VPSL LON LOP COML VIP VIN MODE GAIN VCM RCLMP HILO VPOS VOH VOL COMM ENBV ENBL COMM Description LNA Midsupply Bypass Pin; Connect a Capacitor for Midsupply HF Bypass LNA Input LNA 5 V Supply LNA Inverting Output LNA Noninverting Output LNA Ground VGA Noninverting Input VGA Inverting Input Gain Slope Logic Input Gain Control Voltage Common-Mode Voltage Output Clamping Level Gain Range Select (HI or LO) VGA 5 V Supply Noninverting VGA Output Inverting VGA Output VGA Ground VGA Enable LNA Enable VGA Ground Rev. I | Page 8 of 55 AD8331/AD8332/AD8334 28 LMD1 1 INH2 2 VPS2 3 26 VPS1 LON2 4 25 LON1 LOP2 5 24 LOP1 COM2 6 7 8 21 VIN1 VCM2 9 20 VCM1 RCLMP 11 19 HILO 18 ENB VOH2 12 17 VOH1 VOL2 13 16 VOL1 COMM 14 15 VPSV AD8332 TOP VIEW (Not to Scale) 24 23 22 21 20 19 18 17 COMM VOH1 VOL1 VPSV NC VOL2 VOH2 COMM 9 10 11 12 13 14 15 16 22 VIP1 VIP2 VIN2 GAIN 10 32 31 30 29 28 27 26 25 23 COM1 1 2 3 4 5 6 7 8 LOP2 COM2 VIP2 VIN2 VCM2 MODE GAIN RCLMP TOP VIEW (Not to Scale) LON1 VPS1 INH1 LMD1 LMD2 INH2 VPS2 LON2 NOTES 1. NC = NO CONNECT. 2. THE EXPOSED PAD MUST BE SOLDERED TO THE PCB GROUND TO ENSURE PROPER HEAT DISSIPATION, NOISE, AND MECHANICAL STRENGTH BENEFITS. 03199-004 AD8332 27 INH1 03199-005 LMD2 PIN 1 INDICATOR LOP1 COM1 VIP1 VIN1 VCM1 HILO ENBL ENBV Data Sheet Figure 4. 28-Lead TSSOP Pin Configuration (AD8332) Figure 5. 32-Lead LFCSP Pin Configuration (AD8332) Table 4. 28-Lead TSSOP Pin Function Description (AD8332) Table 5. 32-Lead LFCSP Pin Function Description (AD8332) Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Mnemonic LMD2 INH2 VPS2 LON2 LOP2 COM2 VIP2 VIN2 VCM2 GAIN RCLMP VOH2 VOL2 COMM VPSV VOL1 VOH1 ENB HILO VCM1 VIN1 VIP1 COM1 LOP1 LON1 VPS1 INH1 LMD1 Description CH 2 LNA Midsupply Pin; Connect a Capacitor for Midsupply HF Bypass CH2 LNA Input CH2 Supply LNA 5 V CH2 LNA Inverting Output CH2 LNA Noninverting Output CH2 LNA Ground CH2 VGA Noninverting Input CH2 VGA Inverting Input CH2 Common-Mode Voltage Gain Control Voltage Output Clamping Resistor CH2 Noninverting VGA Output CH2 Inverting VGA Output VGA Ground (Both Channels) VGA Supply 5 V (Both Channels) CH1 Inverting VGA Output CH1 Noninverting VGA Output Enable—VGA/LNA VGA Gain Range Select (HI or LO) CH1 Common-Mode Voltage CH1 VGA Inverting Input CH1 VGA Noninverting Input CH1 LNA Ground CH1 LNA Noninverting Output CH1 LNA Inverting Output CH1 LNA Supply 5 V CH1 LNA Input CH 1 LNA Midsupply Pin; Connect a Capacitor for Midsupply HF Bypass Pin No. 1 2 3 4 Mnemonic LON1 VPS1 INH1 LMD1 5 LMD2 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 INH2 VPS2 LON2 LOP2 COM2 VIP2 VIN2 VCM2 MODE GAIN RCLMP COMM VOH2 VOL2 NC VPSV VOL1 VOH1 COMM ENBV ENBL HILO VCM1 VIN1 VIP1 COM1 LOP1 EPAD Rev. I | Page 9 of 55 Description CH1 LNA Inverting Output CH1 LNA Supply 5 V CH1 LNA Input CH 1 LNA Midsupply Pin; Connect a Capacitor for Midsupply HF Bypass CH 2 LNA Midsupply Pin; Connect a Capacitor for Midsupply HF Bypass CH2 LNA Input CH2 LNA Supply 5 V CH2 LNA Inverting Output CH2 LNA Noninverting Output CH2 LNA Ground CH2 VGA Noninverting Input CH2 VGA Inverting Input CH2 Common-Mode Voltage Gain Slope Logic Input Gain Control Voltage Output Clamping Level Input VGA Ground CH2 Noninverting VGA Output CH2 Inverting VGA Output No Connect VGA Supply 5 V CH1 Inverting VGA Output CH1 Noninverting VGA Output VGA Ground VGA Enable LNA Enable VGA Gain Range Select (HI or LO) CH1 Common-Mode Voltage CH1 VGA Inverting Input CH1 VGA Noninverting Input CH1 LNA Ground CH1 LNA Noninverting Output Exposed Pad. The exposed pad must be soldered to the PCB ground to ensure proper heat dissipation, noise, and mechanical strength benefits. Data Sheet 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 COM2 COM1 INH1 LMD1 NC LON1 LOP1 VIP1 VIN1 VPS1 GAIN12 CLMP12 EN12 EN34 VCM1 VCM2 AD8331/AD8332/AD8334 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 PIN 1 INDICATOR AD8334 TOP VIEW (Not to Scale) 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 COM12 VOH1 VOL1 VPS12 VOL2 VOH2 COM12 MODE NC COM34 VOH3 VOL3 VPS34 VOL4 VOH4 COM34 NOTES 1. THE EXPOSED PADDLE MUST BE SOLDERED TO THE PCB GROUND TO ENSURE PROPER HEAT DISSIPATION, NOISE, AND MECHANICAL STRENGTH BENEFITS. 2. NC = NO CONNECT. 03199-006 COM3 COM4 INH4 LMD4 NC LON4 LOP4 VIP4 VIN4 VPS4 GAIN34 CLMP34 HILO VCM4 VCM3 NC 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 INH2 LMD2 NC LON2 LOP2 VIP2 VIN2 VPS2 VPS3 VIN3 VIP3 LOP3 LON3 NC LMD3 INH3 Figure 6. 64-Lead LFCSP Pin Configuration (AD8334) Table 6. 64-Lead LFCSP Pin Function Description (AD8334) Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Mnemonic INH2 LMD2 NC LON2 LOP2 VIP2 VIN2 VPS2 VPS3 VIN3 VIP3 LOP3 LON3 NC LMD3 INH3 COM3 COM4 INH4 LMD4 NC LON4 LOP4 VIP4 VIN4 VPS4 Description CH2 LNA Input. CH 2 LNA Midsupply Pin; Connect a Capacitor for Midsupply HF Bypass. Not Connected. CH2 LNA Feedback Output (for RIZ). CH2 LNA Output. CH2 VGA Positive Input. CH2 VGA Negative Input. CH2 LNA Supply 5 V. CH3 LNA Supply 5 V. CH3 VGA Negative Input. CH3 VGA Positive Input. CH3 LNA Positive Output. CH3 LNA Feedback Output (for RIZ). Not Connected. CH 3 LNA Midsupply Pin; Connect a Capacitor for Midsupply HF Bypass. CH3 LNA Input. CH3 LNA Ground. CH4 LNA Ground. CH4 LNA Input. CH 4 LNA Midsupply Pin; Connect a Capacitor for Midsupply HF Bypass. Not Connected. CH4 LNA Feedback Output (for RIZ). CH4 LNA Positive Output. CH4 VGA Positive Input. CH4 VGA Negative Input. CH4 LNA Supply 5 V. Rev. I | Page 10 of 55 Data Sheet Pin No. 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 Mnemonic GAIN34 CLMP34 HILO VCM4 VCM3 NC COM34 VOH4 VOL4 VPS34 VOL3 VOH3 COM34 NC MODE COM12 VOH2 VOL2 VPS12 VOL1 VOH1 COM12 VCM2 VCM1 EN34 EN12 CLMP12 GAIN12 VPS1 VIN1 VIP1 LOP1 LON1 NC LMD1 INH1 COM1 COM2 EPAD AD8331/AD8332/AD8334 Description Gain Control Voltage for CH3 and CH4. Output Clamping Level Input for CH3 and CH4. VGA Gain Range Select (HI or LO). CH4 Common-Mode Voltage—AC Bypass. CH3 Common-Mode Voltage—AC Bypass. No Connect. VGA Ground CH3 and CH4. CH4 Positive VGA Output. CH4 Negative VGA Output. VGA Supply 5 V CH3 and CH4. CH3 Negative VGA Output. CH3 Positive VGA Output. VGA Ground CH3 and CH4. No Connect. Gain Control Slope, Logic Input, 0 = Positive. VGA Ground CH1 and CH2. CH2 Positive VGA Output. CH2 Negative VGA Output. CH2 VGA Supply 5 V CH1 and CH2. CH1 Negative VGA Output. CH1 Positive VGA Output. VGA Ground CH1 and CH2. CH2 Common-Mode Voltage—AC Bypass. CH1 Common-Mode Voltage—AC Bypass. Shared LNA/VGA Enable CH3 and CH4. Shared LNA/VGA Enable CH1 and CH2. Output Clamping Level Input CH1 and CH2. Gain Control Voltage CH1 and CH2. CH1 LNA Supply 5 V. CH1 VGA Negative Input. CH1 VGA Positive Input. CH1 LNA Positive Output. CH1 LNA Feedback Output (for RIZ). Not Connected. CH 1 LNA Midsupply Pin; Connect a Capacitor for Midsupply HF Bypass. CH1 LNA Input. CH1 LNA Ground. CH2 LNA Ground. The exposed paddle must be soldered to the PCB ground to ensure proper heat dissipation, noise, and mechanical strength benefits. Rev. I | Page 11 of 55 AD8331/AD8332/AD8334 Data Sheet TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, VS = 5 V, RL = 500 Ω, RS = RIN = 50 Ω, RIZ = 280 Ω, CSH = 22 pF, f = 10 MHz, RCLMP = ∞, CL = 1 pF, VCM pin floating, −4.5 dB to +43.5 dB gain (HILO = LO), and differential output voltage, unless otherwise specified. 50 60 50 PERCENT OF UNITS (%) 30 20 10 HILO = LO 0 0 0.2 0.4 0.6 20 10 ASCENDING GAIN MODE DESCENDING GAIN MODE (WHERE AVAILABLE) 03199-007 –10 30 0.8 1.0 0 –0.5 1.1 03199-010 GAIN (dB) 40 HILO = HI 40 SAMPLE SIZE = 80 UNITS VGAIN = 0.5V –0.4 –0.3 –0.2 –0.1 0 0.1 0.2 0.3 0.4 0.5 GAIN ERROR (dB) VGAIN (V) Figure 10. Gain Error Histogram Figure 7. Gain vs. VGAIN and MODE (MODE Available on RU Package) 25 2.0 20 1.5 SAMPLE SIZE = 50 UNITS VGAIN = 0.2V GAIN ERROR (dB) –40°C PERCENT OF UNITS (%) 15 1.0 +25°C 0.5 0 –0.5 +85°C –1.0 10 5 0 25 20 VGAIN = 0.7V 15 03199-008 0.6 0.8 1.0 0 1.1 VGAIN (V) CHANNEL TO CHANNEL GAIN MATCH (dB) Figure 8. Absolute Gain Error vs. VGAIN at Three Temperatures Figure 11. Gain Match Histogram for VGAIN = 0.2 V and 0.7 V 2.0 50 1.5 1.0 VGAIN = 0.8V 30 VGAIN = 0.6V GAIN (dB) 0.5 1MHz 0 10MHz 30MHz VGAIN = 0.4V 10 VGAIN = 0.2V 50MHz 70MHz 0 0.2 0.4 0.6 0.8 1.0 VGAIN = 0V –10 –20 100k 1.1 03199-012 –1.5 –2.0 20 0 –1.0 03199-009 GAIN ERROR (dB) VGAIN = 1V 40 –0.5 0.19 0.21 0.4 0.11 0.13 0.15 0.17 0.2 0.01 0.03 0.05 0.07 0.09 0 5 –0.17 –0.15 –0.13 –0.11 –0.09 –0.07 –0.05 –0.03 –0.01 –2.0 03199-011 10 –1.5 1M 10M 100M FREQUENCY (Hz) VGAIN (V) Figure 12. Frequency Response for Various Values of VGAIN Figure 9. Absolute Gain Error vs. VGAIN at Various Frequencies Rev. I | Page 12 of 55 500M Data Sheet AD8331/AD8332/AD8334 0 VGAIN = 1V 50 VGAIN = 0.8V 40 VGAIN = 0.6V VOUT = 1V p-p –20 VGAIN = 1.0V 30 VGAIN = 0.4V 20 VGAIN = 0.2V CROSSTALK (dB) GAIN (dB) 60 AD8332 VGAIN = 0.7V –40 AD8334 VGAIN = 0.4V –60 –80 10 VGAIN = 0V 03199-013 –10 100k 1M 10M 100M 03199-016 –100 0 –120 100k 500M 1M FREQUENCY (Hz) 10M 100M FREQUENCY (Hz) Figure 13. Frequency Response for Various Values of VGAIN, HILO = HI Figure 16. Channel-to-Channel Crosstalk vs. Frequency for Various Values of VGAIN 30 50 VGAIN = 0.5V RIN = RS = 75Ω 20 45 RIN = RS = 50Ω RIN = RS = 100Ω RIN = RS = 200Ω RIN = RS = 500Ω –10 RIN = RS = 1kΩ 03199-014 1M 10M 100M 1µF COUPLING 25 20 15 10 –20 –30 100k 30 03199-017 0 0.1µF COUPLING 35 5 0 100k 500M 1M FREQUENCY (Hz) Figure 14. Frequency Response for Various Matched Source Impedances Figure 17. Group Delay vs. Frequency for Two Values of AC Coupling 20 30 T = +85°C T = +25°C T = –40°C HI GAIN VGAIN = 0.5V RIZ = ∞ 10 OFFSET VOLTAGE (mV) 20 10 0 –10 0 –10 –20 20 LO GAIN 10 0 –20 –30 100k 03199-015 GAIN (dB) 100M 10M FREQUENCY (Hz) 1M 10M 100M T = +85°C T = +25°C T = –40°C –10 –20 500M 0 FREQUENCY (Hz) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 03199-018 GAIN (dB) 10 GROUP DELAY (ns) 40 0.9 1.0 1.1 VGAIN (V) Figure 18. Representative Differential Output Offset Voltage vs. VGAIN at Three Temperatures Figure 15. Frequency Response, Unterminated LNA, RS = 50 Ω Rev. I | Page 13 of 55 AD8331/AD8332/AD8334 Data Sheet 50j 30 SAMPLE SIZE = 100 0.2V < VGAIN < 0.7V RIN = 50Ω, RIZ = 270Ω 25 RIN = 6kΩ, RIZ = ∞ f = 100kHz 20 0Ω 17Ω 15 10 RIN = 75Ω, RIZ = 412Ω 0 03199-019 5 49.6 49.7 49.8 49.9 50.0 50.1 50.2 50.3 50.4 RIN = 100Ω, RIZ = 549Ω 50.5 RIN = 200Ω, RIZ = 1.1kΩ –25j –100j 03199-022 GAIN SCALING FACTOR –50j Figure 19. Gain Scaling Factor Histogram 100 Figure 22. Smith Chart, S11 vs. Frequency, 0.1 MHz to 200 MHz for Various Values of RIZ 20 SINGLE ENDED, PIN VOH OR PIN VOL RL = ∞ VIN = 10mV p-p RIN = 50Ω GAIN (dB) RIN = 200Ω 5 RIN = 500Ω 0 RIN = 1kΩ 1 –5 0.1 100k –10 1M 10M RIN = 75Ω –15 100k 100M 1M FREQUENCY (Hz) 10M 100M 500M FREQUENCY (Hz) Figure 23. LNA Frequency Response, Single-Ended, for Various Values of RIN Figure 20. Output Impedance vs. Frequency 20 10k 15 RIZ = ∞ 10 GAIN (dB) 1k 100 0 RIZ = ∞, CSH = 0pF RIZ = 6.65kΩ, CSH = 0pF RIZ = 3.01kΩ, CSH = 0pF RIZ = 1.1kΩ, CSH = 1.2pF 1M RIZ = 549Ω, CSH = 8.2pF RIZ = 412Ω, CSH = 12pF RIZ = 270Ω, CSH = 22pF 10M –10 –15 100k 100M 03199-024 10 100k 5 –5 03199-021 INPUT IMPEDANCE (Ω) RIN = 100Ω 10 10 03199-020 OUTPUT IMPEDANCE (Ω) 15 03199-023 % TOTAL 100j 25j 35 1M 10M 100M 500M FREQUENCY (Hz) FREQUENCY (Hz) Figure 24. Frequency Response for Unterminated LNA, Single-Ended Figure 21. LNA Input Impedance vs. Frequency for Various Values of RIZ and CSH Rev. I | Page 14 of 55 Data Sheet AD8331/AD8332/AD8334 500 1.00 RS = 0, RIZ = ∞, 0.95 VGAIN = 1V, f = 10MHz 300 HI GAIN AD8332 AD8334 LO GAIN AD8331 200 100 0 0 0.2 0.4 0.6 0.8 0.90 0.85 0.80 0.75 0.70 0.65 0.60 03199-028 INPUT-REFERRED NOISE (nV/ Hz) 400 03199-025 0.55 0.50 –50 1.0 –30 –10 VGAIN (V) Figure 25. Output-Referred Noise vs. VGAIN 10 2.0 1.5 1.0 1M 90 10M 1 RS THERMAL NOISE ALONE 0.1 100M 1 10 100 1k SOURCE RESISTANCE (Ω) Figure 26. Short-Circuit, Input-Referred Noise vs. Frequency Figure 29. Input-Referred Noise vs. RS 7 RS = 0, RIZ = ∞, HILO = LO OR HI, f = 10MHz INCLUDES NOISE OF VGA NOISE FIGURE (dB) 6 10 1 5 4 3 2 RIN = 50Ω RIN = 75Ω RIN = 100Ω RIN = 200Ω RIZ = ∞ 0.1 1 03199-027 INPUT-REFERRED NOISE (nV/ Hz) 70 f = 5MHz, RIZ = ∞, VGAIN = 1V FREQUENCY (Hz) 100 50 03199-029 INPUT-REFERRED NOISE (nV/ Hz) RS = 0, RIZ = ∞, VGAIN = 1V, HILO = LO OR HI 0.5 100k 30 Figure 28. Short-Circuit, Input-Referred Noise vs. Temperature 03199-026 INPUT-REFERRED NOISE (nV/ Hz) 2.5 10 TEMPERATURE (°C) 0 0.2 0.4 0.6 0.8 SIMULATED RESULTS 0 50 100 1.0 VGAIN (V) SOURCE RESISTANCE (Ω) Figure 30. Noise Figure vs. RS for Various Values of RIN Figure 27. Short-Circuit, Input-Referred Noise vs. VGAIN Rev. I | Page 15 of 55 03199-030 OUTPUT-REFERRED NOISE (nV/ Hz) f = 10MHz 1k AD8331/AD8332/AD8334 35 Data Sheet PREAMP LIMITED –30 f = 10MHz, RS = 50Ω f = 10MHz, VOUT = 1V p-p 25 20 15 10 HILO HILO HILO HILO 5 0 0 0.1 = LO, RIN = 50Ω = LO, RIZ = ∞ = HI, RIN = 50Ω = HI, RIz = ∞ 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 –50 –60 –70 HILO = HI, HD3 0 200 400 600 800 Figure 31. Noise Figure vs. VGAIN Figure 34. Harmonic Distortion vs. RLOAD –40 30 20 15 10 03199-032 5 f = 10MHz, RS = 50Ω 0 10 15 20 25 30 35 40 45 50 55 –50 HILO = LO, HD2 HILO = LO, HD3 –60 HILO = HI, HD3 –80 –90 60 HILO = HI, HD2 –70 03199-035 NOISE FIGURE (dB) f = 10MHz, VOUT = 1V p-p = LO, RIN = 50Ω = LO, RFB = ∞ = HI, RIN = 50Ω = HI, RFB = ∞ HARMONIC DISTORTION (dBc) HILO HILO HILO HILO 25 0 10 20 40 50 Figure 35. Harmonic Distortion vs. CLOAD Figure 32. Noise Figure vs. Gain –20 G = 30dB VOUT = 1Vp-p HILO = HI, HD2 HILO = HI, HD3 f = 10MHz, GAIN = 30dB –30 –40 –50 –60 –70 –40 HILO = LO, HD3 HILO = LO, HD2 –60 HILO = HI, HD2 HILO = HI, HD3 –80 03199-036 HARMONIC DISTORTION (dBc) HILO = LO, HD2 HILO = LO, HD3 –20 –80 –90 1M 10M FREQUENCY (Hz) 100M 03199-113 HARMONIC DISTORTION (dBc) 30 CLOAD (pF) GAIN (dB) –10 1000 1200 1400 1600 1800 2000 RLOAD (Ω) VGAIN (V) 0 HILO = LO, HD3 –80 –90 1.1 HILO = LO, HD2 HILO = HI, HD2 03199-034 HARMONIC DISTORTION (dBc) –40 03199-031 NOISE FIGURE (dB) 30 –100 0 1 2 3 4 VOUT (V p-p) Figure 36. Harmonic Distortion vs. Differential Output Voltage Figure 33. Harmonic Distortion vs. Frequency Rev. I | Page 16 of 55 Data Sheet AD8331/AD8332/AD8334 0 0 VOUT = 1V p-p VOUT = 1V p-p COMPOSITE (f1 + f2) G = 30dB –10 –20 –30 HILO = LO, HD3 IMD3 (dBc) –40 HILO = LO, HD2 –60 –80 –50 –70 HILO = HI, HD3 HILO = HI, HD2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 –80 HILO = HI –90 1M 1.0 10M VGAIN (V) Figure 40. IMD3 vs. Frequency 0 40 10MHz HILO = HI VOUT = 1V p-p 35 –20 1MHz HILO = LO HILO = LO, HD3 –60 –80 HILO = HI, HD3 10MHz HILO = LO 25 1MHz HILO = HI 20 15 10 HILO = HI, HD2 –100 03199-038 5 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 03199-041 –40 30 HILO = LO, HD2 INPUT RANGE LIMITED WHEN HILO = LO OUTPUT IP3 (dBm) DISTORTION (dBc) 100M FREQUENCY (Hz) Figure 37. Harmonic Distortion vs. VGAIN, f = 1 MHz –120 03199-040 –100 –120 HILO = LO –40 –60 03199-037 DISTORTION (dBc) –20 INPUT RANGE LIMITED WHEN HILO = LO VOUT = 1V p-p COMPOSITE (f1 + f2) 0 1.0 0 0.1 VGAIN (V) 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 VGAIN (V) Figure 41. Output Third-Order Intercept (IP3) vs. VGAIN Figure 38. Harmonic Distortion vs. VGAIN, f = 10 MHz 10 0 100 f = 10MHz HILO = LO HILO = HI 90 –10 –20 10 –30 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 50mV 10ns 1.0 VGAIN (V) Figure 39. IP1dB Compression vs. VGAIN Figure 42. Small Signal Pulse Response, G = 30 dB, Top: Input, Bottom: Output Voltage, HILO = HI or LO Rev. I | Page 17 of 55 03199-042 –40 0 03199-039 IP1dB COMPRESSION (dBm) 2mV AD8331/AD8332/AD8334 Data Sheet 5.0 4.5 20mV 4.0 100 HILO = HI 90 VOUT (V p-p) 3.5 HILO = LO 3.0 2.5 2.0 1.5 10 03199-043 500mV 10ns 03199-046 1.0 0 0.5 0 0 5 10 15 20 25 30 35 40 45 50 70 80 RCLMP (kΩ) Figure 46. Clamp Level vs. RCLMP Figure 43. Large Signal Pulse Response, G = 30 dB, HILO = HI or LO, Top: Input, Bottom: Output Voltage 2 4 CL = 0pF CL = 10pF CL = 22pF CL = 47pF G = 30dB 1 INPUT G = 40dB RCLMP = 48.1kΩ RCLMP = 16.5kΩ 3 2 VOUT (V) 0 INPUT 0 RCLMP = 7.15kΩ RCLMP = 2.67kΩ –1 –1 –2 –40 –30 –20 –10 0 10 20 30 40 –4 –30 50 03199-047 –2 –50 –3 03199-044 INPUT IS NOT TO SCALE –20 TIME (ns) –10 0 10 20 30 40 50 60 TIME (ns) Figure 44. Large Signal Pulse Response for Various Capacitive Loads, CL = 0 pF, 10 pF, 20 pF, 50 pF Figure 47. Clamp Level Pulse Response for Four Values of RCLMP 200mV 500mV 100 90 10 200mV 400ns 03199-045 0 100ns 03199-048 VOUT (V) 1 Figure 48. LNA Overdrive Recovery, VINH 0.05 V p-p to 1 V p-p Burst, VGAIN = 0.27 V VGA Output Shown Figure 45. Pin GAIN Transient Response, Top: VGAIN, Bottom: Output Voltage Rev. I | Page 18 of 55 Data Sheet AD8331/AD8332/AD8334 2V 1V 100 90 10 1V 1ms 03199-052 100ns 03199-049 0 Figure 52. Enable Response, Large Signal, Top: VENB, Bottom: VOUT, VINH = 150 mV p-p Figure 49. VGA Overdrive Recovery, VINH 4 mV p-p to 70 mV p-p Burst, VGAIN = 1 V VGA Output Shown Attenuated by 24 dB 0 VPS1, VGAIN = 0.5V 1V –10 100 –20 90 PSRR (dB) VPSV, VGAIN = 0.5V –30 –40 –50 VPS1, VGAIN = 0V –60 10 0 03199-053 –70 03199-050 100ns –80 100k 1M 10M 100M FREQUENCY (Hz) Figure 50. VGA Overdrive Recovery, VINH 4 mV p-p to 275 mV p-p Burst, VGAIN = 1 V VGA Output Shown Attenuated by 24 dB Figure 53. PSRR vs. Frequency (No Bypass Capacitor) 140 1ms QUIESCENT SUPPLY CURRENT (mA) 03199-051 200mV 130 VGAIN = 0.5V AD8334 120 110 100 90 80 70 AD8332 60 50 40 AD8331 30 20 –40 –20 0 20 40 03199-054 2V 60 80 TEMPERATURE (°C) Figure 51. Enable Response, Top: VENB, Bottom: VOUT, VINH = 30 mV p-p Figure 54. Quiescent Supply Current vs. Temperature Rev. I | Page 19 of 55 100 AD8331/AD8332/AD8334 Data Sheet TEST CIRCUITS dividing the output noise by the numerical gain between Point A and Point B and accounting for the noise floor of the spectrum analyzer. The gain should be measured at each frequency of interest and with low signal levels because a 50 Ω load is driven directly. The generator is removed when noise measurements are made. MEASUREMENT CONSIDERATIONS Figure 55 through Figure 68 show typical measurement configurations and proper interface values for measurements with 50 Ω conditions. Short-circuit input noise measurements are made as shown in Figure 62. The input-referred noise level is determined by NETWORK ANALYZER 50Ω 50Ω OUT IN 18nF 270Ω 0.1µF 237Ω 0.1µF 28Ω INH 1:1 DUT 22pF 237Ω 0.1µF 28Ω 0.1µF LMD *FERRITE BEAD 03199-055 FB* 120nH Figure 55. Test Circuit—Gain and Bandwidth Measurements NETWORK ANALYZER 50Ω OUT 50Ω IN 18nF 10kΩ 0.1µF 0.1µF INH 28Ω 1:1 DUT 22pF 237Ω 0.1µF LMD 0.1µF *FERRITE BEAD 28Ω VGN 03199-056 FB* 10kΩ 120nH 237Ω Figure 56. Test Circuit—Frequency Response for Various Matched Source Impedances NETWORK ANALYZER 50Ω 50Ω 0.1µF FB* 120nH 0.1µF INH 22pF 237Ω 28Ω 1:1 DUT 0.1µF LMD *FERRITE BEAD 0.1µF IN VGN 237Ω 28Ω 03199-057 OUT Figure 57. Test Circuit—Frequency Response for Unterminated LNA, RS = 50 Ω Rev. I | Page 20 of 55 Data Sheet AD8331/AD8332/AD8334 NETWORK ANALYZER OUT 50Ω 50Ω IN 18nF 10kΩ 0.1µF OR 1µF INH 0.1µF 237Ω 28Ω VGA LNA 1:1 22pF 237Ω LMD 0.1µF OR 1µF 0.1µF *FERRITE BEAD 0.1µF 28Ω 03199-058 0.1µF OR 1µF FB* 120nH Figure 58. Test Circuit—Group Delay vs. Frequency for Two Values of AC Coupling 18nF 270Ω NETWORK ANALYZER 0.1µF 50Ω OUT FB* 120nH 0.1µF INH 237Ω 28Ω DUT 50Ω 1:1 22pF 0.1µF 03199-059 0.1µF 237Ω LMD 28Ω *FERRITE BEAD Figure 59. Test Circuit—LNA Input Impedance vs. Frequency in Standard and Smith Chart (S11) Formats NETWORK ANALYZER OUT 50Ω 50Ω IN 0.1µF 0.1µF 237Ω 0.1µF 28Ω 0.1µF INH LNA 1:1 VGA 22pF 237Ω LMD 0.1µF 0.1µF 0.1µF 03199-060 FB* 120nH 28Ω *FERRITE BEAD Figure 60. Test Circuit—Frequency Response for Unterminated LNA, Single-Ended NETWORK ANALYZER 18nF 270Ω 0.1µF INH 1:1 IN 50Ω 28Ω DUT 22pF 237Ω 0.1µF 0.1µF *FERRITE BEAD 237Ω LMD 28Ω Figure 61. Test Circuit—Short-Circuit, Input-Referred Noise Rev. I | Page 21 of 55 03199-061 FB* 120nH 0.1µF AD8331/AD8332/AD8334 Data Sheet SPECTRUM ANALYZER B A GAIN 0.1µF FERRITE BEAD 0.1µF 120nH INH DUT 1:1 22pF 1Ω 50Ω 50Ω 0.1µF SIGNAL GENERATOR TO MEASURE GAIN DISCONNECT FOR NOISE MEASUREMENT 0.1µF 03199-062 49.9Ω IN LMD Figure 62. Test Circuit—Noise Figure SPECTRUM ANALYZER 270Ω AD8332 0.1µF 1kΩ 0.1µF LPF 50Ω –6dB IN 28Ω INH –6dB 1:1 DUT 1kΩ 22pF LMD 50Ω 0.1µF SIGNAL GENERATOR 28Ω 0.1µF 03199-063 18nF Figure 63. Test Circuit—Harmonic Distortion vs. Load Resistance SPECTRUM ANALYZER 18nF 270Ω AD8332 0.1µF 237Ω 0.1µF LPF –6dB IN 50Ω 28Ω INH –6dB 1:1 DUT 237Ω 22pF LMD 50Ω 0.1µF 28Ω 03199-114 SIGNAL GENERATOR 0.1µF Figure 64. Test Circuit—Harmonic Distortion vs. Load Capacitance SPECTRUM ANALYZER +22dB –6dB 18nF 274Ω 50Ω +22dB –6dB 0.1µF INH 0.1µF 237Ω 1:1 237Ω 22pF LMD SIGNAL GENERATORS INPUT 50Ω 28Ω DUT 0.1µF 0.1µF 50Ω –6dB *FERRITE BEAD Figure 65.Test Circuit—IMD3 vs. Frequency Rev. I | Page 22 of 55 28Ω 03199-065 COMBINER –6dB FB* 120nH Data Sheet AD8331/AD8332/AD8334 OSCILLOSCOPE 18nF 270Ω 0.1µF 0.1µF 50Ω IN 28Ω INH DUT 1:1 237Ω 22pF 50Ω 237Ω LMD 0.1µF 0.1µF 28Ω 03199-066 FB* 120nH *FERRITE BEAD Figure 66. Test Circuit—Pulse Response Measurements OSCILLOSCOPE 18nF 270Ω 0.1µF 0.1µF INH 22pF 50Ω RF SIGNAL GENERATOR DIFF PROBE 255Ω CH1 CH2 DUT LMD 0.1µF 255Ω 0.1µF 9.5dB 50Ω TO PIN GAIN OR PIN ENxx *FERRITE BEAD PULSE GENERATOR 03199-067 FB* 120nH Figure 67. Test Circuit—Gain and Enable Transient Response NETWORK ANALYZER TO POWER PINS OUT 50Ω 50Ω IN 18nF 270Ω 0.1µF 22pF 50Ω RF SIGNAL GENERATOR INH 255Ω DIFF PROBE PROBE POWER DUT LMD 0.1µF 0.1µF 255Ω *FERRITE BEAD Figure 68. Test Circuit—PSRR vs. Frequency Rev. I | Page 23 of 55 03199-068 FB* 120nH 0.1µF AD8331/AD8332/AD8334 Data Sheet THEORY OF OPERATION LON1 LOP1 VIP1 VIN1 EN12 OVERVIEW The AD8331/AD8332/AD8334 operate in the same way. Figure 69, Figure 70, and Figure 71 are functional block diagrams of the three devices LON LOP VIP VIN INH2 21dB VOL VGA BIAS AND INTERPOLATOR GAIN INT GAIN INT GAIN12 HILO VOL2 21dB PA2 VOH2 LOP2 + VCM BIAS PA1 VOL1 + ATTENUATOR –48dB – VIP2 VIN2 LMD 21dB LNA 2 LON2 PA CLMP12 CLAMP VOH1 – ATTENUATOR –48dB + VGA BIAS AND INTERPOLATOR VOH ATTENUATOR –48dB VCM BIAS LMD2 3.5dB/ 15.5dB – + LNA – VMID1 LNA 1 LMD1 HILO VCM VMID INH INH1 VCM1 CLAMP RCLMP GAIN UP/ DOWN MODE VMID2 VCM2 VMID3 VCM3 VIN3 03199-069 ENBV ENBL MODE GAIN VIP3 VOH3 – ATTENUATOR –48dB + LOP3 LON3 21dB PA3 VOL3 Figure 69. AD8331 Functional Block Diagram INH3 VCM1 HILO LMD3 VCM BIAS LMD4 LNA 1 LMD1 LNA VMID LMD2 INH2 LNA 2 VGA BIAS AND INTERPOLATOR + ATTENUATOR –48dB – LON2 LOP2 VIP2 VIN2 21dB 21dB PA4 VOH4 AD8334 INH4 VOH1 CLAMP LNA 4 CLMP34 VMID4 PA1 VOL1 GAIN INT LON4 GAIN VOH2 21dB PA2 VOL2 AD8332 VMID ENB VCM2 CLAMP Figure 70. AD8332 Functional Block Diagram LOP4 EN34 VIP4 VIN4 VCM4 Figure 71. AD8334 Functional Block Diagram RCLMP 03199-070 INH1 – ATTENUATOR –48dB + GAIN34 VOL4 + ATTENUATOR –48dB – 3.5dB/ 15.5dB VMID +19dB GAIN INT 03199-071 LON1 LOP1 VIP1 VIN1 VGA BIAS AND INTERPOLATOR LNA 3 Each channel contains an LNA that provides user-adjustable input impedance termination, a differential X-AMP VGA, and a programmable gain postamp with adjustable output voltage limiting. Figure 72 shows a simplified block diagram with external components. HILO LON VIN SIGNAL PATH POSTAMP 3.5dB/15.5dB PREAMPLIFIER 19dB VOH INH 48dB ATTENUATOR LNA 21dB VOL VMID LMD LOP VIP VCM CLAMP VCM BIAS BIAS AND INTERPOLATOR GAIN INTERFACE GAIN Figure 72. Simplified Block Diagram Rev. I | Page 24 of 55 RCLMP 03199-072 AD8331 Data Sheet AD8331/AD8332/AD8334 The linear-in-dB, gain control interface is trimmed for slope and absolute accuracy. The gain range is +48 dB, extending from −4.5 dB to +43.5 dB in LO gain and +7.5 dB to +55.5 dB in HI gain mode. The slope of the gain control interface is 50 dB/V, and the gain control range is 40 mV to 1 V. Equation 1 and Equation 2 are the expressions for gain. GAIN (dB) = 50 (dB/V) × VGAIN − 6.5 dB, (HILO = LO) (1) or GAIN (dB) = 50 (dB/V) × VGAIN + 5.5 dB, (HILO = HI) (2) The ideal gain characteristics are shown in Figure 73. 60 50 LOW NOISE AMPLIFIER (LNA) Good noise performance in the AD8331/AD8332/AD8334 relies on a proprietary ultralow noise preamplifier at the beginning of the signal chain, which minimizes the noise contribution in the following VGA. Active impedance control optimizes noise performance for applications that benefit from input matching. A simplified schematic of the LNA is shown in Figure 74. INH is capacitively coupled to the source. A bias generator establishes dc input bias voltages of 3.25 V and centers the output commonmode levels at 2.5 V. A capacitor CLMD (can be the same value as the input coupling capacitor CINH) is connected from the LMD pin to ground to decouple the LMD bus. The LMD pin is not useable for configuring the LNA as a differential input amplifier. CIZ 30 TO VGA VPOS LOP LON 2.5V 2.5V 20 I0 10 CINH –10 0 0.2 0.4 0.6 03199-073 ASCENDING GAIN MODE DESCENDING GAIN MODE (WHERE AVAILABLE) 0 I0 –a HILO = LO 0.8 1.0 INH –a 3.25V Q1 60Ω RS 1.1 3.25V 80Ω CSH I0 VGAIN (V) Q2 40Ω VCM BIAS I0 Figure 73. Ideal Gain Control Characteristics The gain slope is negative with MODE pulled high (where available), as follows: GAIN (dB) = −50 (dB/V) × VGAIN + 45.5 dB, (HILO = LO) CLMD Figure 74. Simplified LNA Schematic (3) or GAIN (dB) = −50 (dB/V) × VGAIN + 57.5 dB, (HILO = HI) LMD 03199-074 GAIN (dB) RIZ HILO = HI 40 (4) The LNA converts a single-ended input to a differential output with a voltage gain of 19 dB. If only one output is used, the gain is 13 dB. The inverting output is used for active input impedance termination. Each of the LNA outputs is capacitively coupled to a VGA input. The VGA consists of an attenuator with a range of 48 dB followed by an amplifier with 21 dB of gain for a net gain range of −27 dB to +21 dB. The X-AMP, gain interpolation technique results in low gain error and uniform bandwidth, and differential signal paths minimize distortion. The final stage is a logic programmable amplifier with gains of 3.5 dB or 15.5 dB. The LO and HI gain modes are optimized for 12-bit and 10-bit ADC applications, in terms of output-referred noise and absolute gain range. Output voltage limiting can be programmed by the user. The LNA supports differential output voltages as high as 5 V p-p, with positive and negative excursions of ±1.25 V, about a common-mode voltage of 2.5 V. Because the differential gain magnitude is 9, the maximum input signal before saturation is ±275 mV or +550 mV p-p. Overload protection ensures quick recovery time from large input voltages. Because the inputs are capacitively coupled to a bias voltage near midsupply, very large inputs can be handled without interacting with the ESD protection. Low value feedback resistors and the current-driving capability of the output stage allow the LNA to achieve a low input-referred voltage noise of 0.74 nV/√Hz. This is achieved with a current consumption of only 11 mA per channel (55 mW). On-chip resistor matching results in precise single-ended gains of 4.5× (9× differential), critical for accurate impedance control. The use of a fully differential topology and negative feedback minimizes distortion. Low HD2 is particularly important in second harmonic ultrasound imaging applications. Differential signaling enables smaller swings at each output, further reducing third-order distortion. Rev. I | Page 25 of 55 AD8331/AD8332/AD8334 Data Sheet Active Impedance Matching UNTERMINATED The LNA supports active impedance matching through an external shunt feedback resistor from Pin LON to Pin INH. The input resistance, RIN, is given in Equation 5, where A is the singleended gain of 4.5, and 6 kΩ is the unterminated input impedance. VOUT + – RESISTIVE TERMINATION (5) RIN RS CIZ is needed in series with RIZ because the dc levels at Pin LON and Pin INH are unequal. Expressions for choosing RIZ in terms of RIN and for choosing CIZ are found in the Applications Information section. CSH and the ferrite bead enhance stability at higher frequencies, where the loop gain is diminished, and prevent peaking. Frequency response plots of the LNA are shown in Figure 23 and Figure 24. The bandwidth is approximately 130 MHz for matched input impedances of 50 Ω to 200 Ω and declines at higher source impedances. The unterminated bandwidth (when RIZ = ∞) is approximately 80 MHz. VIN VOUT + RS – ACTIVE IMPEDANCE MATCH - RS = RIN RIZ RIN RS VIN VOUT + – RIN = RIZ 1 + 4.5 Figure 75. Input Configurations Each output can drive external loads as low as 100 Ω in addition to the 100 Ω input impedance of the VGA (200 Ω differential). Capacitive loading up to 10 pF is permissible. All loads should be ac-coupled. Typically, Pin LOP output is used as a single-ended driver for auxiliary circuits, such as those used for Doppler ultrasound imaging. Pin LON drives RIZ. Alternatively, a differential external circuit can be driven from the two outputs in addition to the active feedback termination. In both cases, important stability considerations discussed in the Applications Information section should be carefully observed. 7 INCLUDES NOISE OF VGA RESISTIVE TERMINATION (RS = RIN) 5 4 3 ACTIVE IMPEDANCE MATCH 2 The impedance at each LNA output is 5 Ω. A 0.4 dB reduction in open circuit gain results when driving the VGA, and a 0.8 dB reduction results with an additional 100 Ω load at the output. The differential gain of the LNA is 6 dB higher. If the load is less than 200 Ω on either side, a compensating load is recommended on the opposite output. 1 LNA Noise 7 The input-referred voltage noise sets an important limit on system performance. The short-circuit input voltage noise of the LNA is 0.74 nV/√Hz or 0.82 nV/√Hz (at maximum gain), including the VGA noise. The open circuit, current noise is 2.5 pA/√Hz. These measurements, taken without a feedback resistor, provide the basis for calculating the input noise and noise figure performance of the configurations in Figure 75. Figure 76 and Figure 77 show simulations extracted from these results and the 4.1 dB noise figure (NF) measurement with the input actively matched to a 50 Ω source. Unterminated (RIZ = ∞) operation exhibits the lowest equivalent input noise and noise figure. Figure 76 shows the noise figure vs. source resistance, rising at low RS, where the LNA voltage noise is large compared to the source noise, and again at high RS due to current noise. The VGA input-referred voltage noise of 2.7 nV/√Hz is included in all of the curves. 6 SIMULATION 0 50 100 03199-076 NOISE FIGURE (dB) 6 UNTERMINATED 1k RS (Ω) Figure 76. Noise Figure vs. RS for Resistive, Active Match, and Unterminated Inputs NOISE FIGURE (dB) INCLUDES NOISE OF VGA 5 4 3 2 RIN = 50Ω RIN = 75Ω RIN = 100Ω RIN = 200Ω RIZ = ∞ 1 03199-077 6 kΩ × RIZ RIZ 6 kΩ = 1+ A 33 kΩ + RIZ VIN 03199-075 RIN = RIN RS (SIMULATED RESULTS) 0 50 100 1k RS (Ω) Figure 77. Noise Figure vs. RS for Various Fixed Values of RIN, Actively Matched Rev. I | Page 26 of 55 Data Sheet AD8331/AD8332/AD8334 The primary purpose of input impedance matching is to improve the system transient response. With resistive termination, the input noise increases due to the thermal noise of the matching resistor and the increased contribution of the LNA input voltage noise generator. With active impedance matching, however, the contributions of both are smaller than they would be for resistive termination by a factor of 1/(1 + LNA Gain). Figure 76 shows their relative NF performance. In this graph, the input impedance is swept with RS to preserve the match at each point. The noise figures for a source impedance of 50 Ω are 7.1 dB, 4.1 dB, and 2.5 dB, respectively, for the resistive, active, and unterminated configurations. The noise figures for 200 Ω are 4.6 dB, 2.0 dB, and 1.0 dB, respectively. Figure 77 is a plot of NF vs. RS for various values of RIN, which is helpful for design purposes. The plateau in the NF for actively matched inputs mitigates source impedance variations. For comparison purposes, a preamp with a gain of 19 dB and noise spectral density of 1.0 nV/√Hz, combined with a VGA with 3.75 nV/√Hz, yields a noise figure degradation of approximately 1.5 dB (for most input impedances), significantly worse than the AD8331/AD8332/AD8334 performance. The equivalent input noise of the LNA is the same for singleended and differential output applications. The LNA noise figure improves to 3.5 dB at 50 Ω without VGA noise, but this is exclusive of noise contributions from other external circuits connected to LOP. A series output resistor is usually recommended for stability purposes when driving external circuits on a separate board (see the Applications Information section). In low noise applications, a ferrite bead is even more desirable. VARIABLE GAIN AMPLIFIER The differential X-AMP VGA provides precise input attenuation and interpolation. It has a low input-referred noise of 2.7 nV/√Hz and excellent gain linearity. A simplified block diagram is shown in Figure 78. GAIN GAIN INTERPOLATOR (BOTH CHANNELS) + POSTAMP gm VIP 6dB R 200Ω 48dB 2R – POSTAMP Figure 78. Simplified VGA Schematic 03199-078 VIN X-AMP VGA The input of the VGA is a differential R-2R ladder attenuator network with 6 dB steps per stage and a net input impedance of 200 Ω differential. The ladder is driven by a fully differential input signal from the LNA and is not intended for single-ended operation. LNA outputs are ac-coupled to reduce offset and isolate their common-mode voltage. The VGA inputs are biased through the center tap connection of the ladder to VCM, which is typically set to 2.5 V and is bypassed externally to provide a clean ac ground. The signal level at successive stages in the input attenuator falls from 0 dB to −48 dB in +6 dB steps. The input stages of the X-AMP are distributed along the ladder, and a biasing interpolator, controlled by the gain interface, determines the input tap point. With overlapping bias currents, signals from successive taps merge to provide a smooth attenuation range from 0 dB to −48 dB. This circuit technique results in excellent linear-in-dB gain law conformance and low distortion levels and deviates ±0.2 dB or less from the ideal. The gain slope is monotonic with respect to the control voltage and is stable with variations in process, temperature, and supply. The X-AMP inputs are part of a gain-of-12 feedback amplifier that completes the VGA. Its bandwidth is 150 MHz. The input stage is designed to reduce feedthrough to the output and to ensure excellent frequency response uniformity across gain setting (see Figure 12 and Figure 13). Gain Control Position along the VGA attenuator is controlled by a single-ended analog control voltage, VGAIN, with an input range of 40 mV to 1.0 V. The gain control scaling is trimmed to a slope of 50 dB/V (20 mV/dB). Values of VGAIN beyond the control range saturate to minimum or maximum gain values. Both channels of the AD8332 are controlled from a single gain interface to preserve matching. Gain can be calculated using Equation 1 and Equation 2. Gain accuracy is very good because both the scaling factor and absolute gain are factory trimmed. The overall accuracy relative to the theoretical gain expression is ±1 dB for variations in temperature, process, supply voltage, interpolator gain ripple, trim errors, and tester limits. The gain error relative to a best-fit line for a given set of conditions is typically ±0.2 dB. Gain matching between channels is better than 0.1 dB (Figure 11 shows gain errors in the center of the control range). When VGAIN < 0.1 or > 0.95, gain errors are slightly greater. The gain slope can be inverted, as shown in Figure 73 (except for the AD8332 AR models). The gain drops with a slope of −50 dB/V across the gain control range from maximum to minimum gain. This slope is useful in applications such as automatic gain control, where the control voltage is proportional to the measured output signal amplitude. The inverse gain mode is selected by setting the MODE pin to HI gain mode. Gain control response time is less than 750 ns to settle within 10% of the final value for a change from minimum to maximum gain. Rev. I | Page 27 of 55 AD8331/AD8332/AD8334 Data Sheet VGA Noise Common-Mode Biasing In a typical application, a VGA compresses a wide dynamic range input signal to within the input span of an ADC. While the input-referred noise of the LNA limits the minimum resolvable input signal, the output-referred noise, which depends primarily on the VGA, limits the maximum instantaneous dynamic range that can be processed at any one particular gain control voltage. This limit is set in accordance with the quantization noise floor of the ADC. An internal bias network connected to a midsupply voltage establishes common-mode voltages in the VGA and postamp. An externally bypassed buffer maintains the voltage. The bypass capacitors form an important ac ground connection because the VCM network makes a number of important connections internally, including the center tap of the VGA differential input attenuator, the feedback network of the VGA fixed gain amplifier, and the feedback network of the postamp in both gain settings. For best results, use a 1 nF capacitor and a 0.1 µF capacitor in parallel, with the 1 nF capacitor nearest to the VCM pin. Separate VCM pins are provided for each channel. For dc coupling to a 3 V ADC, the output common-mode voltage is adjusted to 1.5 V by biasing the VCM pin. The output-referred noise is flat over most of the gain range because it is dominated by the fixed output-referred noise of the VGA. Values are 48 nV/√Hz in LO gain mode and 178 nV/√Hz in HI gain mode. At the high end of the gain control range, the noise of the LNA and the noise of the source prevail. The inputreferred noise reaches its minimum value near the maximum gain control voltage, where the input-referred contribution of the VGA becomes very small. POSTAMPLIFIER The final stage has a selectable gain of 3.5 dB (×1.5) or 15.5 dB (×6), set by the HILO logic pin. Figure 79 is a simplified block diagram. + VOH Gm1 At lower gains, the input-referred noise, and thus noise figure, increases as the gain decreases. The instantaneous dynamic range of the system is not lost, however, because the input capacity increases with it. The contribution of the ADC noise floor has the same dependence as well. The important relationship is the magnitude of the VGA output noise floor relative to that of the ADC. With its low output-referred noise levels, these devices ideally drive low voltage ADCs. The converter noise floor drops 12 dB for every two bits of resolution and drops at lower input fullscale voltages and higher sampling rates. ADC quantization noise is discussed in the Applications Information section. The preceding noise performance discussion applies to a differential VGA output signal. Although the LNA noise performance is the same in single-ended and differential applications, the VGA performance is not. The noise of the VGA is significantly higher in single-ended usage because the contribution of its bias noise is designed to cancel in the differential signal. A transformer can be used with single-ended applications when low noise is desired. Gain control noise is a concern in very low noise applications. Thermal noise in the gain control interface can modulate the channel gain. The resultant noise is proportional to the output signal level and usually only evident when a large signal is present. Its effect is observable only in LO gain mode where the noise floor is substantially lower. The gain interface includes an on-chip noise filter, which reduces this effect significantly at frequencies above 5 MHz. Care should be taken to minimize noise impinging at the GAIN input. An external RC filter can be used to remove VGAIN source noise. The filter bandwidth should be sufficient to accommodate the desired control bandwidth. Gm2 F2 F1 VCM Gm2 VOL – Gm1 03199-079 Output- and input-referred noise as a function of VGAIN are plotted in Figure 25 and Figure 27 for the short circuited input conditions. The input noise voltage is simply equal to the output noise divided by the measured gain at each point in the control range. Figure 79. Postamplifier Block Diagram Separate feedback attenuators implement the two gain settings. These are selected in conjunction with an appropriately scaled input stage to maintain a constant 3 dB bandwidth between the two gain modes (~150 MHz). The slew rate is 1200 V/µs in HI gain mode and 300 V/µs in LO gain mode. The feedback networks for HI and LO gain modes are factory trimmed to adjust the absolute gains of each channel. Noise The topology of the postamp provides constant input-referred noise with the two gain settings and variable output-referred noise. The output-referred noise in HI gain mode increases (with gain) by four. This setting is recommended when driving converters with higher noise floors. The extra gain boosts the output signal levels and noise floor appropriately. When driving circuits with lower input noise floors, the LO gain mode optimizes the output dynamic range. Although the quantization noise floor of an ADC depends on a number of factors, the 48 nV/√Hz and 178 nV/√Hz levels are well suited to the average requirements of most 12-bit and 10-bit converters, respectively. An additional technique, described in the Applications Information section, can extend the noise floor even lower for possible use with 14-bit ADCs. Rev. I | Page 28 of 55 Data Sheet AD8331/AD8332/AD8334 Output Clamping 5.0 Outputs are internally limited to a level of 4.5 V p-p differential when operating at a 2.5 V common-mode voltage. The postamp implements an optional output clamp engaged through a resistor from RCLMP to ground. Table 8 shows a list of recommended resistor values. 4.5 The accuracy of the clamping levels is approximately ±5% in LO or HI mode. Figure 80 illustrates the output characteristics for a few values of RCLMP. Rev. I | Page 29 of 55 3.5 RCLMP = ∞ 8.8kΩ 3.5kΩ 3.0 2.5 RCLMP = 1.86kΩ 2.0 3.5kΩ 1.5 8.8kΩ 1.0 0.5 0 –3 RCLMP = ∞ –2 –1 03199-080 VOH, VOL (V) Output clamping can be used for ADC input overload protection, if needed, or postamp overload protection when operating from a lower common-mode level, such as 1.5 V. The user should be aware that distortion products increase as output levels approach the clamping levels, and the user should adjust the clamp resistor accordingly. For additional information, see the Applications Information section. 4.0 0 1 2 VINH (V) Figure 80. Output Clamping Characteristics 3 AD8331/AD8332/AD8334 Data Sheet APPLICATIONS INFORMATION CLMD 0.1µF The LMD pin (connected to the bias circuitry) must be bypassed to ground and signal sourced to the INH pin, which is capacitively coupled using 2.2 nF to 0.1 µF capacitors (see Figure 81). 1 2 +5V The unterminated input impedance of the LNA is 6 kΩ. The user can synthesize any LNA input resistance between 50 Ω and 6 kΩ. RIZ is calculated according to Equation 6 or selected from Table 7. 33 kΩ × (RIN ) (6) 6 kΩ – (RIN ) RIZ (Nearest STD 1% Value, Ω) 280 412 562 1.13 k 3.01 k ∞ 5 6 7 0.1µF Table 7. LNA External Component Values for Common Source Impedances RIN (Ω) 50 75 100 200 500 6k 4 1nF 9 VGAIN 10 11 0.1µF INH2 INH1 VPS2 VPS1 LON2 LON1 LOP2 LOP1 COM2 COM1 VIP2 VIP1 VIN2 VIN1 VCM2 VCM1 GAIN HILO RCLMP ENB 28 0.1µF CSH* 27 5V CIZ* 26 RIZ* 1nF 25 0.1µF LNA OUT 24 23 22 0.1µF 21 20 5V 1nF 1nF CSH (pF) 22 12 8 1.2 None None 8 LMD1 1nF 12 13 14 VOH2 VOH1 VOL2 VOL1 COMM VPSV 0.1µF 19 18 5V 17 * 16 * VGA OUT VGA OUT 15 5V 1nF 0.1µF *SEE TEXT When active input termination is used, a decoupling capacitor (CIS) is required to isolate the input and output bias voltages of the LNA. Figure 81. Basic Connections for a Typical Channel (AD8332 Shown) The shunt input capacitor, CSH, reduces gain peaking at higher frequencies where the active termination match is lost due to the gain roll-off of the LNA at high frequencies. The value of CSH diminishes as RIN increases to 500 Ω, at which point no capacitor is required. Suggested values for CSH for 50 Ω ≤ RIN ≤ 200 Ω are shown in Table 7. RIZ 5Ω VIP TO EXT CIRCUIT 50Ω LON 3.25V 100Ω VCM 2.5V LNA 2.5V CSH When a long trace to Pin INH is unavoidable, or if both LNA outputs drive external circuits, a small ferrite bead (FB) in series with Pin INH preserves circuit stability with negligible effect on noise. The bead shown is 75 Ω at 100 MHz (Murata BLM21 or equivalent). Other values can prove useful. Figure 82 shows the interconnection details of the LNA output. Capacitive coupling between the LNA outputs and the VGA inputs is required because of the differences in their dc levels and the need to eliminate the offset of the LNA. Capacitor values of 0.1 µF are recommended. There is a 0.4 dB loss in gain between the LNA output and the VGA input due to the 5 Ω output resistance. Additional loading at the LOP and LON outputs affects LNA gain. LNA DECOUPLING RESISTOR 3.25V 5Ω 50Ω LOP 100Ω VIN LNA DECOUPLING RESISTOR TO EXT CIRCUIT 03199-082 RIZ = 3 LMD2 LNA SOURCE FB 03199-081 LNA—EXTERNAL COMPONENTS Figure 82. Interconnections of the LNA and VGA Both LNA outputs are available for driving external circuits. Pin LOP should be used in those instances when a single-ended LNA output is required. The user should be aware of stray capacitance loading of the LNA outputs, in particular LON. The LNA can drive 100 Ω in parallel with 10 pF. If an LNA output is routed to a remote PC board, it tolerates a load capacitance up to 100 pF with the addition of a 49.9 Ω series resistor or ferrite 75 Ω/100 MHz bead. Rev. I | Page 30 of 55 Data Sheet AD8331/AD8332/AD8334 Gain Input Optional Output Voltage Limiting The GAIN pin is common to both channels of the AD8332. The input impedance is nominally 10 MΩ, and a bypass capacitor from 100 pF to 1 nF is recommended. The RCLMP pin provides the user with a means to limit the output voltage swing when used with loads that have no provisions for prevention of input overdrive. The peak-to-peak limited voltage is adjusted by a resistor to ground (see Table 8 for a list of several voltage levels and corresponding resistor values). Unconnected, the default limiting level is 4.5 V p-p. VCM Input The common-mode voltage of Pin VCM, Pin VOL, and Pin VOH defaults to 2.5 V dc. With output ac-coupled applications, the VCM pin is unterminated; however, it must still be bypassed in close proximity for ac grounding of internal circuitry. The VGA outputs can be dc connected to a differential load, such as an ADC. Common-mode output voltage levels between 1.5 V and 3.5 V can be realized at Pin VOH and Pin VOL by applying the desired voltage at Pin VCM. DC-coupled operation is not recommended when driving loads on a separate PC board. The voltage on the VCM pin is sourced by an internal buffer with an output impedance of 30 Ω and a ±2 mA default output current (see Figure 83). If the VCM pin is driven from an external source, its output impedance should be <<30 Ω, and its current drive capability should be >>2 mA. If the VCM pins of several devices are connected in parallel, the external buffer should be capable of overcoming their collective output currents. When a common-mode voltage other than 2.5 V is used, a voltagelimiting resistor, RCLMP, is needed to protect against overload. INTERNAL CIRCUITRY 30Ω VCM 100pF RO << 30Ω NEW VCM 0.1µF AC GROUNDING FOR INTERNAL CIRCUITRY 03199-083 2mA MAX Figure 83. VCM Interface Logic Inputs—ENB, MODE, and HILO The input impedance of all enable pins is nominally 25 kΩ and can be pulled up to 5 V (a pull-up resistor is recommended) or driven by any 3 V or 5 V logic families. The enable pin, ENB, powers down the VGA; when pulled low, the VGA output voltages are near ground. Multiple devices can be driven from a common source. Consult Table 3, Table 4, Table 5, and Table 6 for information about circuit functions controlled by the enable pins. Pin HILO is compatible with 3 V or 5 V CMOS logic families. It is either connected to ground or pulled up to 5 V, depending on the desired gain range and output noise. –20 VGAIN = 0.75V –30 –40 –50 HILO = LO –60 HILO = HI –70 –80 1.5 03199-084 If gain control noise in LO gain mode becomes a factor, maintaining ≤15 nV/√Hz noise at the GAIN pin ensures satisfactory noise performance. Internal noise prevails below 15 nV/√Hz at the GAIN pin. Gain control noise is negligible in HI gain mode. Note that third harmonic distortion increases as waveform amplitudes approach clipping. For lowest distortion, the clamp level should be set higher than the converter input span. A clamp level of 1.5 V p-p is recommended for a 1 V p-p linear output range, 2.7 V p-p for a 2 V p-p range, or 1 V p-p for a 0.5 V p-p operation. The best solution is determined experimentally. Figure 84 shows third harmonic distortion as a function of the limiting level for a 2 V p-p output signal. A wider limiting level is desirable in HI gain mode. HD3 (dBc) Parallel connected devices can be driven by a common voltage source or DAC. Decoupling should take into account any bandwidth considerations of the drive waveform, using the total distributed capacitance. 2.0 2.5 3.0 3.5 4.0 4.5 5.0 CLAMP LIMIT LEVEL (V p-p) Figure 84. HD3 vs. Clamping Level for 2 V p-p Differential Input Table 8. Clamp Resistor Values Clamp Level (V p-p) 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.4 Clamp Resistor Value (kΩ) HILO = LO HILO = HI 1.21 2.74 2.21 4.75 4.02 7.5 6.49 11 9.53 16.9 14.7 26.7 23.2 49.9 39.2 100 73.2 Output Decoupling When driving capacitive loads greater than about 10 pF, or long circuit connections on other boards, an output network of resistors and/or ferrite beads can be useful to ensure stability. These components can be incorporated into a Nyquist filter such as the one shown in Figure 81. In Figure 81, the resistor value is 84.5 Ω. For example, all the evaluation boards for this series incorporate 100 Ω in parallel with a 120 nH bead. Lower value resistors are permissible for applications with nearby loads or Rev. I | Page 31 of 55 AD8331/AD8332/AD8334 Data Sheet with gains less than 40 dB. The exact values of these components can be selected empirically. An antialiasing noise filter is typically used with an ADC. Filter requirements are application dependent. When the ADC resides on a separate board, the majority of filter components should be placed nearby to suppress noise picked up between boards and to mitigate charge kickback from the ADC inputs. Any series resistance beyond that required for output stability should be placed on the ADC board. Figure 85 shows a second-order, low-pass filter with a bandwidth of 20 MHz. The capacitor is chosen in conjunction with the 10 pF input capacitance of the ADC. OPTIONAL BACKPLANE 158Ω 18pF ADC POSTAMP OVERLOAD 25mV 56.5 41dB The relative noise and distortion performance of the two gain modes can be compared in Figure 25 and Figure 31 through Figure 41. The 48 nV/√Hz noise floor of the LO gain mode is suited to converters with higher sampling rates or resolutions (such as 12 bits). Both gain modes can accommodate ADC fullscale voltages as high as 4 V p-p. Because distortion performance remains favorable for output voltages as high as 4 V p-p (see Figure 36), it is possible to lower the output-referred noise even further by using a resistive attenuator (or transformer) at the output. The circuit in Figure 86 has an output full-scale range of 2 V p-p, a gain range of −10.5 dB to +37.5 dB, and an output noise floor of 24 nV/√Hz, making it suitable for some 14-bit ADC applications. 187Ω 187Ω 374Ω LPF ADC AD6644 03199-086 2:1 VOL 2V p-p DIFF, 24nV/ Hz –4.5 1m 24.5dB LO GAIN MODE LNA OVERLOAD The output drive accommodates a wide range of ADCs. The noise floor requirements of the VGA depend on a number of application factors, including bit resolution, sampling rate, fullscale voltage, and the bandwidth of the noise/antialias filter. The output noise floor and gain range can be adjusted by selecting HI or LO gain mode. GAIN (dB) DRIVING ADCs VOH 25mV 29dB Figure 85. 20 MHz Second-Order, Low-Pass Filter 4V p-p DIFF, 48nV/ Hz X-AMP OVERLOAD 4mV 10m 0.1 0.275 1 7.5 1m 24.5dB HI GAIN MODE 10m 0.1 0.275 1 INPUT AMPLITUDE (V) INPUT AMPLITUDE (V) 03199-087 1.5µH 43.5 X-AMP OVERLOAD 15mV LNA OVERLOAD 0.1µF POSTAMP OVERLOAD 158Ω Figure 87. Overload Gain and Signal Conditions The clamp interface mentioned in the Output Clamping section controls the maximum output swing of the postamp and its overload response. When the clamp feature is not used, the output level defaults to approximately 4.5 V p-p differential centered at 2.5 V common mode. When other common-mode levels are set through the VCM pin, the value of RCLMP should be selected for graceful overload. A value of 8.3 kΩ or less is recommended for 1.5 V or 3.5 V common-mode levels (7.2 kΩ for HI gain mode). This limits the output swing to just above 2 V p-p differential. OPTIONAL INPUT OVERLOAD PROTECTION Applications in which high transients are applied to the LNA input can benefit from the use of clamp diodes. A pair of backto-back Schottky diodes can reduce these transients to manageable levels. Figure 88 illustrates how such a diode protection scheme can be connected. OPTIONAL SCHOTTKY OVERLOAD CLAMP FB Figure 86. Adjusting the Noise Floor for 14-Bit ADCs OVERLOAD RSH 3 These devices respond gracefully to large signals that overload its input stage and to normal signals that overload the VGA when the gain is set unexpectedly high. Each stage is designed for clean-limited overload waveforms and fast recovery when gain setting or input amplitude is reduced. Rev. I | Page 32 of 55 COMM 20 0.1µF CSH 2 CIZ RIZ INH ENBL 19 3 VPSL 4 LON 2 1 BAS40-04 Figure 88. Input Overload Clamping 03199-088 1.5µH GAIN (dB) 84.5Ω 0.1µF Both stages of the VGA are susceptible to overload. Postamplifier limiting is more common and results in the cleanlimited output characteristics found in Figure 49. Recovery is fast in all cases. The graph in Figure 87 summarizes the combinations of input signal and gain that lead to the different types of overload. 03199-085 84.5Ω Signals larger than ±275 mV at the LNA input are clipped to 5 V p-p differential prior to the input of the VGA. Figure 48 shows the response to a 1 V p-p input burst. The symmetric overload waveform is important for applications, such as CW Doppler ultrasound, where the spectrum of the LNA outputs during overload is critical. The input stage is also designed to accommodate signals as high as ±2.5 V without triggering the slow-settling ESD input protection diodes. Data Sheet AD8331/AD8332/AD8334 ADG736 When selecting overload protection, the important parameters are forward and reverse voltages and trr (or rr). The Infineon BAS40-04 series shown in Figure 88 has a rr of 100 ps and a VF of 310 mV at 1 mA. Many variations of these specifications can be found in vendor catalogs. 1.13kΩ SELECT RIZ 280Ω LON 18nF LAYOUT, GROUNDING, AND BYPASSING 5Ω 200Ω INH LNA LMD 50Ω 5Ω LOP 03199-090 Due to their excellent high frequency characteristics, these devices are sensitive to their PCB environments. Realizing expected performance requires attention to detail critical to good, high speed, board design. 0.1µF AD8332 A multilayer board with power and ground planes is recommended with blank areas in the signal layers filled with ground plane. Be certain that the power and ground pins provided for robust power distribution to the device are connected. Decouple the power supply pins with surface-mount capacitors as close as possible to each pin to minimize impedance paths to ground. Decouple the LNA power pins from the VGA supply using ferrite beads. Together with the capacitors, ferrite beads eliminate undesired high frequencies without reducing the headroom. Use a larger value capacitor for every 10 chips to 20 chips to decouple residual low frequency noise. To minimize voltage drops, use a 5 V regulator for the VGA array. Figure 89. Accommodating Multiple Sources DISABLING THE LNA Where accessible, connection of the LNA enable pin to ground powers down the LNA, resulting in a current reduction of about half. In this mode, the LNA input and output pins can be left unconnected; however, the power must be connected to all the supply pins for the disabling circuit to function. Figure 90 illustrates the connections using AD8331 as an example. Several critical LNA areas require special care. The LON and LOP output traces must be as short as possible before connecting to the coupling capacitors connected to Pin VIN and Pin VIP. RIZ must be placed near the LON pin as well. Resistors must be placed as close as possible to the VGA output pins, VOL and VOH, to mitigate loading effects of connecting traces. Values are discussed in the Output Decoupling section. NC 1 LMD COMM 20 AD8331 NC +5V 2 3 NC Signal traces must be short and direct to avoid parasitic effects. Wherever there are complementary signals, symmetrical layout should be employed to maintain waveform balance. PCB traces should be kept adjacent when running differential signals over a long distance. NC 4 5 INH ENBL VPSL ENBV LON COMM LOP VOL 19 18 +5V 17 16 VOUT 6 COML VOH 15 MULTIPLE INPUT MATCHING Matching of multiple sources with dissimilar impedances can be accomplished as shown in Figure 89. A relay and low supply voltage analog switch can be used to select between multiple sources and their associated feedback resistors. An ADG736 dual SPDT switch is shown in this example; however, multiple switches are also available and users are referred to the Analog Devices Selection Guide for switches and multiplexers. 0.1µF VIN 0.1µF MODE 7 8 9 VIP VPOS VIN HILO MODE RCLMP 14 13 +5V HILO 12 RCLMP 10 GAIN VCM 11 VCM 03199-089 GAIN Figure 90. Disabling the LNA Rev. I | Page 33 of 55 AD8331/AD8332/AD8334 Data Sheet ULTRASOUND TGC APPLICATION HIGH DENSITY QUAD LAYOUT The AD8332 ideally meets the requirements of medical and industrial ultrasound applications. The TGC amplifier is a key subsystem in such applications because it provides the means for echo location of reflected ultrasound energy. The AD8334 is the ideal solution for applications with limited board space. Figure 94 represents four channels routed to and away from this very compact quad VGA. Note that none of the signal paths crosses and that all four channels are spaced apart to eliminate crosstalk. Figure 91 through Figure 93 are schematics of a dual, fully differential system using the AD8332 and the AD9238 12-bit high speed ADC with conversion speeds as high as 65 MSPS. In this example, all of the components shown are 0402 size; however, the same layout is executable at the expense of slightly more board area. The sketch also assumes that both sides of the printed circuit board are available for components and that the bypass and power supply decoupling circuitry is located on the wiring side of the board. Rev. I | Page 34 of 55 Data Sheet AD8331/AD8332/AD8334 S3 EIN2 TP5 AD8332ARU C50 0.1µF LMD2 LMD1 28 2 +5V CFB2 18nF + C80 22pF RFB2 274Ω INH1 C41 0.1µF 3 VPS2 VPS1 C74 1nF L6 120nH FB +5VLNA 5 6 7 VCM1 8 LON2 LON1 LOP2 LOP1 COM2 COM1 VIP2 VIP1 VIN2 VIN1 C48 0.1µF TP2 GAIN TP7 GND C78 1nF 9 10 VCM2 VCM1 GAIN HILO C83 1nF RFB1 274Ω 25 24 C42 0.1µF 23 C59 0.1µF 22 21 20 C69 0.1µF JP8 DC2H RCLMP ENB C68 1nF VOH2 R27 100Ω L19 SAT L17 SAT C54 0.1µF L11 120nH FB 13 C67 L20 SAT SAT L18 JP12 SAT C55 0.1µF L10 120nH FB 14 JP7 DC2L C43 0.1µF +5VGA 19 18 12 VIN–B CFB1 18nF HI GAIN JP10 LO GAIN +5VGA 11 R3 (RCLMP) C66 SAT S1 EIN1 26 C77 1nF VIN+B C60 0.1µF VCM1 JP13 OPTIONAL 4-POLE LOW-PASS FILTER C79 22pF +5VLNA 4 C53 0.1µF L13 120nH FB 27 JP6 IN1 L7 120nH FB +5VGA C51 0.1µF INH2 JP5 IN2 +5VLNA C46 1µF TP6 C70 0.1µF L12 120nH FB TB1 +5V TP4 (BLACK) TB2 GND C49 0.1µF VOH1 VOL2 VOL1 COMM VPSV ENABLE JP16 DISABLE 17 R24 100Ω 16 15 JP9 OPTIONAL 4-POLE LOW-PASS FILTER L9 120nH FB C58 0.1µF L1 SAT L15 SAT L8 120nF FB JP17 C56 0.1µF L14 SAT C64 SAT L16 SAT VIN+A C65 SAT VIN–A R26 100Ω +5VGA C45 0.1µF R25 100Ω C85 1nF JP10 Figure 91. Schematic, TGC, VGA Section Using an AD8332 and AD9238 Rev. I | Page 35 of 55 03199-091 TP3 (RED) 1 AD8331/AD8332/AD8334 3 + 2 1 IN OUT GND C22 0.1µF C31 0.1µF L4 120nH FB C30 0.1µF OUT TAB L3 120nH FB R5 33Ω VIN+_A L2 120nH FB 1 2 3 R6 33Ω R4 C18 1.5kΩ C17 1nF C33 0.1µF 10µF 6.3V + C40 0.1µF R12 1.5kΩ C35 0.1µF C1 0.1µF C36 0.1µF 4 5 6 C52 10nF TP9 C32 + 0.1µF VREF C34 10µF 6.3V C38 0.1µF 8 C12 10µF 6.3V 9 C57 10nF C39 10µF C37 0.1µF VIN–_B VIN+_B 13 14 15 R7 33Ω R18 499Ω 16 17 C20 0.1µF R16 5kΩ R17 49.9Ω C15 1nF C62 18pF +3.3VCLK C63 0.1µF 11 12 1.5kΩ S2 EXT CLOCK 7 10 C16 1.5kΩ 0.1µF R8 33Ω C19 1nF 18 19 R19 499Ω JP3 JP11 R20 4.7kΩ R41 4.7kΩ 20 21 22 +3.3VCLK ADCLK + C86 0.1µF 4 1 VDD OE 20MHz 3 OUT GND 2 U6 SG-636PCE C47 10µF 6.3V ADCLK JP4 3 4 DNC DNC TP 12 U5 74VHC04 U5 74VHC04 EXT 3 1 R9 0Ω 2 2 1 INT U5 74VHC04 5 6 U5 74VHC04 9 TP 13 DATA CLK 1 JP1 SPARES D0_B D1_B D2_B 2 23 24 25 26 27 28 3 8 29 D3_B 30 U5 74VHC04 D4_B 31 13 12 D5_B 32 11 10 AGND AVDD VIN+_A CLK_A VIN–_A SHARED_REF AGND MUX_SELECT AVDD PDWN_A REFT_A OEB_A REFB_A OTR_A VREF D11_A (MSB) SENSE D10_A D9_A REFB_B REFT_B AVDD AGND VIN–_B VIN+_B AGND AVDD CLK_B D8_A DRGND D7_A D6_A D5_A D4_A D3_A DCS D2_A DFS D1_A PDWN_B D0_A OEB_B DNC DNC DNC DNC DRVDD D0_B DRGND D1_B OTR_B D2_B C26 0.1µF D11_B (MSB) DRGND DRVDD D3_B D4_B D5_B C24 1nF Figure 92. Converter Schematic, TGC Using an AD8332 and AD9238 Rev. I | Page 36 of 55 64 63 62 D10_B D9_B D8_B D7_B D6_B R11 100Ω R10 JP2 0Ω SHARED REF Y N 61 R14 4.7kΩ 60 R15 +3.3VADDIG 0Ω 59 58 OTR_A 57 D11_A 56 D10_A 55 D9_A 54 D8_A +3.3VADDIG 53 DRVDD 52 +3.3VADDIG U5 74VHC04 ADCLK + C61 18pF VIN–_A C29 0.1µF C2 10µF 6.3V C21 1nF 51 50 49 48 47 46 45 44 43 42 C23 0.1µF C25 1nF D7_A D6_A D5_A D4_A D3_A D2_A D1_A D0_A DNC DNC 41 40 39 38 37 36 35 34 33 C13 1nF C14 + 0.1µF C11 10µF 6.3V OTR_B D11_B D10_B D9_B D8_B D7_B D6_B 03199-092 +5V +3.3VAVDD L5 120nH FB U1 A/D CONVERTER AD9238 VR1 ADP3339AKC-3.3 C44 1µF Data Sheet Data Sheet AD8331/AD8332/AD8334 DATACLKA 1 OTR_A D11_A D10_A D9_A D7_A D6_A RP 9 8 7 3 6 4 5 5 8 6 7 7 3 6 8 4 5 1 2 22 × 4 RP 10 9 G1 A4 Y4 A5 Y5 A6 Y6 A7 A8 Y7 Y8 + C3 0.1µF C28 10µF 6.3V R40 22Ω +3.3VDVDD 2 1 8 4 3 7 6 5 3 6 8 7 15 4 5 10 9 14 1 22 × 4 8 12 11 13 2 RP2 7 14 13 12 3 6 16 11 4 5 18 20 1 2 22 × 4 RP 1 1 22 × 4 8 2 RP 3 7 22 3 6 24 4 5 26 +3.3VDVDD 1 U7 VCC 20 74VHC541 10 G2 GND 2 18 A1 Y1 3 17 A2 Y2 G1 D5_A D4_A D3_A D2_A D1_A D0_A DNC DNC 1 2 22 × 4 RP 11 3 8 7 6 4 4 5 1 22 × 4 2 RP 12 5 8 6 7 7 3 6 8 4 5 9 A3 Y3 A4 Y4 A5 Y5 A6 Y6 A7 Y7 A8 Y8 C10 + 0.1µF C8 0.1µF 19 C76 10µF 6.3V 16 HEADER UP MALE NO SHROUD D8_A 2 22 × 4 20 U10 VCC 74VHC541 19 10 G2 GND 18 2 Y1 A1 17 3 A2 Y2 4 16 A3 Y3 1 15 17 19 21 23 25 1 22 × 4 8 28 2 RP 4 7 30 29 3 6 32 31 4 5 34 33 36 35 15 14 13 27 38 37 40 39 12 SAM080UPM 11 +3.3VDVDD 1 OTR_B D11_B D10_B D9_B D7_B D6_B D5_B RP 13 8 7 3 6 4 5 1 2 22 × 4 RP 14 3 8 7 6 4 1 U2 G1 VCC 74VHC541 10 G2 GND 18 2 A1 Y1 3 17 A2 Y2 16 4 A3 Y3 5 15 A4 Y4 14 6 A5 Y5 7 13 A6 Y6 12 8 A7 Y7 9 11 A8 Y8 5 22 × 4 + C7 0.1µF 19 8 + C9 0.1µF C27 10µF 6.3V +3.3VDVDD 1 RP 15 20 U3 VCC 74VHC541 10 G2 GND 2 18 A1 Y1 G1 19 D4_B D3_B D2_B D1_B D0_B DNC DNC 2 7 3 6 4 1 2 5 22 × 4 RP 16 8 7 3 4 5 6 3 6 7 4 5 8 9 A2 Y2 A3 Y3 A4 Y4 A5 Y5 A6 Y6 A7 Y7 A8 Y8 C4 0.1µF C5 0.1µF C6 0.1µF + C75 10µF 6.3V 41 44 43 1 22 × 4 8 46 45 2 RP 5 7 48 47 3 6 50 49 4 5 52 51 53 1 22 × 4 8 54 2 RP 6 7 56 3 6 58 4 5 60 62 1 22 × 4 8 2 RP 7 7 64 3 6 66 4 5 68 55 57 59 61 63 65 67 1 22 × 4 8 70 69 2 RP 8 7 72 71 3 6 74 73 4 5 76 75 17 16 15 14 13 12 R39 22Ω 11 DATACLK Figure 93. Interface Schematic, TGC Using an AD8332 and AD9238 Rev. I | Page 37 of 55 42 HEADER UP MALE NO SHROUD D8_B 2 22 × 4 20 78 77 80 79 SAM080UPM 03199-093 1 Data Sheet AD8331/AD8332/AD8334 CH2 LNA INPUT CH3 LNA INPUT CH1 LNA INPUT CH4 LNA INPUT 63 61 LMD1 LMD4 60 NC NC 59 57 56 55 54 53 52 29 51 30 50 31 49 32 VCM4 EN34 VCM3 VCM1 NC VCM2 COM34 VOH4 VOL4 VPS34 VOL3 VOH3 COM34 NC MODE COM12 VOH2 VOL2 VPS12 VOL1 VOH1 COM12 EN12 58 28 HILO 62 INH1 INH4 64 27 CLMP12 CLMP34 INH2 COM1 COM4 1 26 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 NC = NO CONNECT CH1 DIFFERENTIAL OUTPUT CH2 DIFFERENTIAL OUTPUT CH3 DIFFERENTIAL OUTPUT CH4 DIFFERENTIAL OUTPUT Figure 94. Compact Signal Path and Board Layout for the AD8334 LMD2 NC AD8334 25 03199-094 2 3 4 LON2 LOP2 24 Rev. I | Page 38 of 55 5 23 POWER SUPPLY DECOUPLING LOCATED ON WIRING SIDE GAIN12 GAIN34 6 22 VPS1 VPS4 VIP2 21 VIN1 VIN4 7 20 VIP1 VIP4 VIN2 19 LOP1 LOP4 VPS2 VPS3 VIN3 VIP3 LOP3 LON3 NC LMD3 INH3 18 LON1 LON4 8 9 10 11 12 13 14 15 16 17 COM2 COM3 Data Sheet AD8331/AD8332/AD8334 AD8331 EVALUATION BOARD GENERAL DESCRIPTION The AD8331 evaluation board is a platform for testing and evaluating the AD8331 variable gain amplifier (VGA). The board is provided completely assembled and tested; the user simply connects an input signal, VGAIN sources, and a 5 V power supply. The AD8331-EVALZ is lead free and RoHS compliant. Figure 95 is a photograph of the board. USER-SUPPLIED OPTIONAL COMPONENTS As shipped, the LNA input impedance of the AD8331-EVALZ is configured for 50 Ω to accommodate most signal generators and network analyzers. Input impedances up to 6 kΩ are realized by changing the values of RFB and CSH. Refer to the Theory of Operation section for details on this circuit feature. See Table 9 for typical values of input impedance and corresponding components. Table 9. LNA External Component Values for Common Source Impedances RIN (Ω) 50 75 100 200 500 6k RFB (Ω, Nearest 1% Value) 274 412 562 1.13 k 3.01 k ∞ Figure 95. Photograph of AD8331-EVALZ MEASUREMENT SETUP The basic board connection for measuring bandwidth is shown in Figure 97. A 5 V, 100 mA minimum power supply and a low noise, voltage reference supply for GAIN are required. Table 10 lists jumpers, and Figure 97 shows their functions and positions. The preferred signal detection method is a differential probe connected to VO, as shown in Figure 97. Single-ended loads can be connected using the board edge SMA connector, VOH. Be sure to take into account the 25.8 dB attenuation incurred when using the board in this manner. For connection to an ADC, the 270 Ω series resistors can be replaced with 0 Ω or other appropriate values. CSH (pF) 22 12 8 1.2 None None Table 10. Jumper Functions The board is designed for 0603 size, surface-mount components. Back-to-back diodes can be installed at Location D3 if desired. To evaluate the LNA as a standalone amplifier, install optional SMA connectors LON and LOP and capacitors C1 and C2; typical values are 0.1 μF or smaller. At R4 and R8, 0 Ω resistors are installed unless capacitive loads larger than 10 pF are connected to the SMA connectors LON and LOP (such as coaxial cables). In that event, small value resistors (68 Ω to 100 Ω) must be installed at R4 and R8 to preserve the stability of the amplifier. A resistor can be inserted at RCLMP if output clamping is desired. Refer to Table 8 for appropriate values. 03199-115 As shown in the schematic in Figure 96, the board provides for optional components. The components shown in black are for typical operation, and the components shown in gray are installed at the user’s discretion. Switch LNA_EN VGA_EN W5, W6 GN_SLOPE GN_HI_LO Function Enables the LNA when in the top position Enables the VGA when in the top position Connects the AD8331 outputs to the SMA connectors Left = gain increases with VGAIN Right = gain decreases with VGAIN Left = high gain Right = LO gain BOARD LAYOUT The evaluation board circuitry uses four conductor layers. The two inner layers are grounded, and all interconnecting circuitry is located on the outer layers. Figure 99 to Figure 102 illustrate the copper patterns. Rev. I | Page 39 of 55 AD8331/AD8332/AD8334 Data Sheet AD8331 EVALUATION BOARD SCHEMATICS GND1 GND2 GND +5V GND3 GND4 + CINH 0.1µF L1 120nH FB PROBE 3 INPUT CLAMP DIODES CLMD 0.1µF D1 CFB 0.018µF RFB 274µF L2 120nH FB BAT64-04 +5V LON 3 C6 0.1µF 20 ENB INH VPS ENBV 19 DISABLE 18 ENABLE VGA_EN DISABLE DUT 4 LON COMM LOP VOL 17 LO C2 R8 ENABLE LNA_EN AD8331ARQ C1 R4 COMM +5V 2 CSH 22pF LMD2 5 16 L3 120nH FB R44 100Ω LOP 6 C16 0.1µF COML VOH 15 7 VIP VPOS 14 VIN HILO 13 W6 C26 0.1µF R16 237Ω T1 1:1 R20 237Ω VOH L4 120nH FB C32 0.1µF 8 C24 0.1µF VO R43 100Ω C14 0.1µF W5 L5 120nH FB +5V HI GN_HI_LO LO +5V RCLMP DOWN GN_SLOPE UP MODE CLMP 12 C17 0.1µF 10 GAIN COMPONENTS IN GRAY ARE OPTIONAL AND USER SUPPLIED. 9 GAIN VCM C34 1nF 11 VCM C18 0.1µF Figure 96. Schematic of the AD8331 Evaluation Board Rev. I | Page 40 of 55 RCLMP 03199-116 LNA2 1 C3 10µF 10V Data Sheet AD8331/AD8332/AD8334 4395A ANALYZER GN D 1103 TEKPROBE POWER SUPPLY E3631A POWER SUPPLY +5V GND INSERT JUMPERS W5 AND W6 TO USE OUTPUT TRANSFORMER AND VOH SMA Figure 97. AD8331 Typical Board Test Connections Rev. I | Page 41 of 55 03199-117 DIFFERENTIAL PROBE TO VO PINS DP8200 PRECISION VOLTAGE REFERENCE (FOR VGAIN) AD8331/AD8332/AD8334 Data Sheet 03199-118 03199-201 AD8331 EVALUATION BOARD PCB LAYERS Figure 98. AD8331-EVALZ Assembly 03199-202 03199-199 Figure 101. Internal Layer Ground Figure 102. Power Plane 03199-200 03199-119 Figure 99. Primary Side Copper Figure 100. Secondary Side Copper Figure 103. Top Silkscreen Rev. I | Page 42 of 55 Data Sheet AD8331/AD8332/AD8334 AD8332 EVALUATION BOARD GENERAL DESCRIPTION The AD8332-EVALZ is a platform for the testing and evaluation of the AD8332 variable gain amplifier (VGA). The board is shipped assembled and tested, and users need only connect the signal and VGAIN sources to a single 5 V power supply. Figure 104 is a photograph of the component side of the board, and Figure 105 shows the schematic. The AD8332-EVALZ is lead free and RoHS compliant. Table 11. LNA External Component Values for Common Source Impedances RIN (Ω) 50 75 100 200 500 6k RFB1, RFB2 (Ω Std 1% Value) 274 412 562 1.13 k 3.01 k ∞ CSH1, CSH2 (pF) 22 12 8 1.2 None None SMA connectors, S2, S3, S6, and S7, are provided for access to the LNA outputs or the VGA inputs. If the LNA is used alone, 0.1 µF coupling capacitors can be installed at the C5, C9, C23, and C24 locations. Resistors of 68 Ω to 100 Ω may be required if the load capacitances, as seen by the LNA outputs, are larger than approximately 10 pF. 03199-131 A resistor can be inserted at RCLMP if output clamping is desired. The peak-to-peak clamping level is adjusted by installing one of the standard 1% resistor values listed in Table 8. Figure 104.Photograph of the AD8332-EVALZ USER-SUPPLIED OPTIONAL COMPONENTS The board is built and tested using the components shown in black in Figure 105. Provisions are made for optional components (shown in gray) that can be installed for testing at user discretion. The default LNA input impedance is 50 Ω to match various signal generators and network analyzers. Input impedances up to 6 kΩ are realized by changing the values of RFBx and CSHx. For reference, Table 11 lists the common input impedance values and corresponding adjustments. The board is designed for 0603 size, surface-mount components. A high frequency differential probe connected to the 2-pin headers, VOx, is the preferred method to observe a waveform at the VGA output. A typical setup is shown in Figure 106. Single-ended loads can be connected directly via the board edge SMA connectors. Note that the AD8332 output amplifier is buffered with 237 Ω resistors; therefore, be sure to compensate for attenuation if low impedances are connected to the output SMAs. MEASUREMENT SETUP The basic board connections for measuring bandwidth are shown in Figure 106. A 5 V, 100 mA (minimum) power supply is required, and a low noise voltage reference supply is required for VGAIN. BOARD LAYOUT The evaluation board circuitry uses four conductor layers. The two inner layers are power and ground planes, and all interconnecting circuitry is located on the outer layers. Figure 108 to Figure 111 illustrate the copper patterns. Rev. I | Page 43 of 55 AD8331/AD8332/AD8334 Data Sheet EVALUATION BOARD SCHEMATICS C25 10µF GND GND1 GND2 GND3 GND4 + 1 C2 0.1µF C4 0.1µF L1 120nH FB LNA2 CSH2 22pF LMD1 28 C1 0.1µF 2 INH2 INH1 CFB1 18nF 3 +5V +5VLNA C6 0.1µF RFB2 274Ω C9 C3 0.1µF CSH1 22pF 27 CFB2 18nF CAL2 L8 120nH FB S6 LON2 LMD2 VPS2 VPS1 LON2 LON1 +5VLNA C7 0.1µF RFB1 274Ω C23 25 W8 5 LOP2 LOP1 W9 24 C5 C24 R12 6 COM2 COM1 8 C10 0.1µF VCM2 9 VIP2 VIP1 VIN2 VIN1 VCM2 VCM1 22 21 20 VCM1 C17 0.1µF 10 GAIN GAIN HILO 19 RCLMP 11 VOH2 C11 0.1µF W12 W6 VO2 W13 R14 237Ω C12 0.1µF ENB 18 LO +5V ENABLE W4 DISABLE C20 0.1µF L3 120nH FB R13 237Ω RCLMP +5V HI W5 C8 1nF TP3 CLAMP C15 0.1µF C13 0.1µF 7 12 VOH2 VOH1 17 R7 100Ω L6 120nH FB R5 100Ω 13 R8 100Ω L4 120nH FB S3 LOP1 R11 23 C14 0.1µF C16 0.1µF T2 1:1 S2 LON1 R9 R10 S7 LOP2 LNA1 CAL1 26 AD8332ARUZ 4 L2 120nH FB 14 VOL2 COMM VOL1 VPSV 16 R6 100Ω 15 W10 C19 0.1µF W11 C18 0.1µF W7 VO1 R15 237Ω T1 1:1 VOH1 R16 237Ω L5 120nH FB L7 120nH FB COMPONENTS IN GRAY ARE OPTIONAL AND USER SUPPLIED. +5V C22 0.1µF Figure 105. Schematic of the AD8332 Evaluation Board Rev. I | Page 44 of 55 03199-096 +5V Data Sheet AD8331/AD8332/AD8334 NETWORK ANALYZER 1103 TEKPROBE POWER SUPPLY VGAIN SUPPLY 03199-120 DIFFERENTIAL PROBE Figure 106. AD8332 Typical Board Test Connections Rev. I | Page 45 of 55 AD8331/AD8332/AD8334 Data Sheet 03199-121 03199-101 AD8332 EVALUATION BOARD PCB LAYERS Figure 107. AD8332-EVALZ Assembly 03199-099 03199-102 Figure 110. Ground Plane Figure 108. Primary Side Copper 03199-103 03199-100 Figure 111. Power Plane Figure 109. Secondary Side Copper Figure 112. Component Side Silkscreen Rev. I | Page 46 of 55 Data Sheet AD8331/AD8332/AD8334 AD8334 EVALUATION BOARD GENERAL DESCRIPTION 03199-122 The AD8334-EVALZ is a platform for the testing and evaluation of the AD8334 variable gain amplifier (VGA). The board is shipped assembled and tested, and users need only connect the signal and VGAIN sources and a single 5 V power supply. Figure 113 is a photograph of the board. The AD8334-EVALZ is lead free and RoHS compliant. Figure 113. AD8334-EVALZ Top View Rev. I | Page 47 of 55 AD8331/AD8332/AD8334 Data Sheet CONFIGURING THE INPUT IMPEDANCE Viewing Signals The board is built and tested using the components shown in black in Figure 115. Provisions are made for optional components (shown in gray) that can be installed at user discretion. As shipped, the input impedances of the low noise amplifiers (LNAs) are configured for 50 Ω to match the output impedances of most signal generators and network analyzers. Input impedances up to 6 kΩ can be realized by changing the values of the feedback resistors, RFB1, RFB2, RFB3, RFB4, and shunt capacitors, C6, C8, C10, and C12. For reference, Table 12 lists standard values of 1% resistors for some typical values of input impedance. Of course, if the user has determined that the source impedance falls between these values, the feedback resistor value can be calculated accordingly. Note that the board is designed to accept standard surface-mount, size 0603 components. The preferred signal detector is a high impedance differential probe, such as the Tektronix P6247, 1 GHz differential probe, connected to the 2-pin headers (VO1, VO2, VO3, or VO4), as shown in Figure 116. The low capacitance of this probe has the least effect on the performance of the device of any detection method tried. The probe can also be used for monitoring input signals at IN1, IN2, IN3, or IN4. It can be used for probing other circuit nodes; however, be aware that the 200 kΩ input impedance can affect certain circuits. Table 12. LNA External Component Values for Common Source Impedances RIN (Ω) 50 75 100 200 500 6k RFB1, RFB2, RFB3, RFB4 (Ω, ±1%) 274 412 562 1.13 k 3.01 k No resistor Differential-to-single-ended transformers are provided for single-ended output connections. Note that series resistors are provided to protect against accidental output overload should a 50 Ω load be connected to the connector. Of course, the effect of these resistors is to limit the bandwidth. If the load connected to the SMA is >500 Ω, the 237 Ω series resistors, RX1, RX2, RX3, RX4, RX5, RX6, RX7, and RX8, can be replaced with 0 Ω values. C6, C8, C10, C12 (pF) 22 12 8 1.2 No capacitor No capacitor Driving the VGA from an External Source or Using the LNA to Drive an External Load Provisions are made for surface-mount SMA connectors that can be used for driving from either direction. If the LNA is not used, it is recommended that the capacitors, C16, C17, C21, C22, C26, C27, C31, and C32, be carefully removed to avoid driving the outputs of the LNAs. Using the Clamp Circuit The board is shipped with no resistors installed in the spaces provided for clamp-circuit operation. Note that each pair of channels shares a clamp resistor. If the output clamping is desired, the resistors are installed in R49 and R50. The peak-topeak clamping level is application dependent. 03199-123 Appropriate components can be installed if the user wants to drive the VGA directly from an external source or to evaluate the LNA output. If the LNA is used to drive off-board loads or cables, small value series resistors (47 Ω to 100 Ω) are recommended for LNA decoupling. These can be installed in the R10, R11, R14, R15, R18, R19, R22, and R23 spaces. Figure 114. AD8334-EVALZ Assembly MEASUREMENT SETUP The basic board connections for measuring bandwidth are shown in Figure 116. A 5 V, 200 mA (minimum) power supply is required, and a low noise voltage reference supply is required for VGAIN. BOARD LAYOUT The evaluation board circuitry uses four conductor layers. The two inner layers are ground, and all interconnecting circuitry is located on the outer layers. Figure 117 to Figure 120 illustrate the copper patterns. Rev. I | Page 48 of 55 Data Sheet AD8331/AD8332/AD8334 EVALUATION BOARD SCHEMATICS 1 2 4 LO2 1 5 6 7 C69 0.1 µF 8 L3 +5V 120 nH 9 C67 0.1 µF C82 1 nF VC M2 EN34 VC M1 EN12 G A IN 12 VIN1 VPS1 L O P1 IN H1 VIN2 COM12 AD8334 VPS2 NC VOH3 VOL3 LON3 VPS34 NC VOL4 LMD3 18 19 21 22 23 C4 0.1 µF C12 22 pF CR3 20 C11 0.1 µF RFB4 CFB4 274Ω 18 nF 26 28 27 L8 1 120 nHR22 31 R23 1 LO4 1 CLMP34 R50 4.02kΩ RX3 100Ω 45 44 40 39 38 +5V L13 120 nH D SLO PE U L14 120 nH RX5 100Ω 37 36 VO3 RX6 100Ω 35 34 L15 120 nH L34 120 nH +5V 32 C77 0.1 µF C62 0.1 µF L16 120 nH HI +5V RX7 100Ω LO VO2 RX4 100Ω 43 N C3 VC M3 VC M4 H IL O 30 L11 120 nH COM34 33 HIL O L4 120 nH +5V 3 29 C32 0.1 µF ICR4 2 25 C31 0.1 µF IN4 1 24 C6 4 0.1 µF 17 VOH4 C55 0.1 µ F INH3 C3 0.1µF 3 COMM34 G A IN34 15 47 46 42 +5V C75 0.1 µF 48 MODE 41 VPS3 2 3 COM12 VOH2 C8 0 1 nF 1 IN3 L12 120 nH FB 49 VIP2 G A IN34 ICR3 14 16 C10 22 pF 50 VOL2 C1 3 0.1 µ F INH3 C9 0.1 µF 51 LOP2 VPS4 L6 120 nH 52 VIN3 C26 0.1 µF 11 VIP3 12 LOP3 RFB3 274Ω CFB3 18 nF R19 53 10 13 1 54 VPSV2 VIN4 R18 C27 0.1 µF 55 VO1 L10 120 nH C59 0.1 µF 56 VIP4 LO3 1 1 RX2 100Ω C57 D 0.1 µF LON2 L O P4 C71 0.1 µF D E VOL1 NC L2 +5V 120 nH C21 0.1 µF 57 58 L O N4 C22 R151 0Ω 0.1 µF 59 E NC L M D4 3 60 EN34 VOH1 C O M4 2 CR2 3 C2 0.1 µF 61 RX1 100Ω EN 12 LMD2 IN H4 RFB2 274Ω R141 0Ω INH2 62 C O M1 1 C O M2 C8 22 pF IN2 ICR2 1 CFB2 18 nF C O M3 C7 0.1 µF L7 120 nH INH2 63 VIP 1 C1 0.1 µF 3 64 C16 0.1 µF NC CR1 C17 0.1 µF CFB1 18 nF RFB1 274Ω C5 0.1 µF C6 22 pF LON 1 2 R10 L M D1 1 L1 120 nH 1 R11 1 C53 0.1 µ F C L M P12 LO1 L5 120 nH IN1 ICR1 L9 120 nH R49 4.02kΩ C L M P12 + C14 10 µF +5V +5V INH1 G ND1 G ND2 G ND3 G ND4 G ND5 G ND6 C L M P34 + 5V VO4 RX8 100Ω L17 120 nH CR4 03199-124 NOTES 1 COMPONENTS IN GRAY ARE OPTIONAL USER SUPPLIED. 2 NC = NO CONNECT. Figure 115. AD8334-EVALZ Schematic Rev. I | Page 49 of 55 AD8331/AD8332/AD8334 Data Sheet PROBE POWER SUPPLY PRECISION VOLTAGE REFERENCE (FOR VGAIN) GAIN CONTROL VOLTAGE GND NETWORK ANALYZER +5V DIFFERENTIAL PROBE POWER SUPPLY SIGNAL INPUT 03199-125 GND Figure 116. AD8334 Typical Board Test Connections (One Channel Shown) Rev. I | Page 50 of 55 Data Sheet AD8331/AD8332/AD8334 03199-126 03199-128 AD8334 EVALUATION BOARD PCB LAYERS Figure 119. AD8334-EVALZ Inner Layer 1Copper Figure 118. AD8334-EVALZ Secondary Side Copper 03199-129 03199-127 Figure 117. AD8334-EVALZ Primary Side Copper Figure 120. AD8334-EVALZ Inner Layer 2 Copper Rev. I | Page 51 of 55 Data Sheet 03199-130 AD8331/AD8332/AD8334 Figure 121. AD8334-EVALZ Component Side Silkscreen Rev. I | Page 52 of 55 Data Sheet AD8331/AD8332/AD8334 OUTLINE DIMENSIONS 9.80 9.70 9.60 28 15 4.50 4.40 4.30 6.40 BSC 1 14 PIN 1 0.65 BSC 1.20 MAX 0.15 0.05 COPLANARITY 0.10 0.30 0.19 SEATING PLANE 8° 0° 0.20 0.09 0.75 0.60 0.45 COMPLIANT TO JEDEC STANDARDS MO-153-AE Figure 122. 28-Lead Thin Shrink Small Outline Package (TSSOP) (RU-28) Dimensions shown in millimeters 0.345 (8.76) 0.341 (8.66) 0.337 (8.55) 20 11 10 0.010 (0.25) 0.004 (0.10) COPLANARITY 0.004 (0.10) 0.010 (0.25) 0.006 (0.15) 0.069 (1.75) 0.053 (1.35) 0.065 (1.65) 0.049 (1.25) 0.025 (0.64) BSC SEATING PLANE 0.012 (0.30) 0.008 (0.20) 8° 0° 0.050 (1.27) 0.016 (0.41) COMPLIANT TO JEDEC STANDARDS MO-137-AD CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. Figure 123. 20-Lead Shrink Small Outline Package (QSOP) (RQ-20) Dimensions shown in Inches and (millimeters Rev. I | Page 53 of 55 0.020 (0.51) 0.010 (0.25) 0.041 (1.04) REF 09-12-2014-A 1 0.158 (4.01) 0.154 (3.91) 0.150 (3.81) 0.244 (6.20) 0.236 (5.99) 0.228 (5.79) AD8331/AD8332/AD8334 Data Sheet 5.10 5.00 SQ 4.90 PIN 1 INDICATOR 0.30 0.25 0.18 1 24 0.50 BSC 3.25 3.10 SQ 2.95 EXPOSED PAD 8 17 TOP VIEW 0.80 0.75 0.70 16 9 0.05 MAX 0.02 NOM COPLANARITY 0.08 0.20 REF SEATING PLANE 0.25 MIN BOTTOM VIEW FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET. 112408-A 0.50 0.40 0.30 PIN 1 INDICATOR 32 25 COMPLIANT TO JEDEC STANDARDS MO-220-WHHD. Figure 124. 32-Lead Lead Frame Chip Scale Package (LFCSP) 5 mm × 5 mm Body and 0.75 mm Package Height (CP-32-7) Dimensions shown in millimeters 9.10 9.00 SQ 8.90 0.60 MAX 0.60 MAX 64 49 48 1 PIN 1 INDICATOR PIN 1 INDICATOR 8.85 8.75 SQ 8.65 0.50 BSC 0.50 0.40 0.30 33 32 0.05 MAX 0.02 NOM 0.30 0.23 0.18 0.25 MIN 0.20 REF FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET. *COMPLIANT TO JEDEC STANDARDS MO-220-VMMD-4 EXCEPT FOR EXPOSED PAD DIMENSION Figure 125. 64-Lead Lead Frame Chip Scale Package (LFCSP) 9 mm × 9 mm Body and 0.85 mm Package Height (CP-64-1) Dimensions shown in millimeters Rev. I | Page 54 of 55 06-13-2012-A SEATING PLANE 16 7.50 REF 0.80 MAX 0.65 TYP 12° MAX 4.70 SQ 4.55 17 BOTTOM VIEW TOP VIEW 1.00 0.85 0.80 *4.85 EXPOSED PAD Data Sheet AD8331/AD8332/AD8334 ORDERING GUIDE Model 1 AD8331ARQZ AD8331ARQZ-RL AD8331ARQZ-R7 AD8331-EVALZ AD8332ACPZ-R2 AD8332ACPZ-R7 AD8332ACPZ-RL AD8332ARUZ AD8332ARUZ-R7 AD8332ARUZ-RL AD8332-EVALZ AD8334ACPZ AD8334ACPZ-REEL AD8334ACPZ-REEL7 AD8334-EVALZ 1 Temperature Range –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C Package Description 20-Lead Shrink Small Outline Package (QSOP) 20-Lead Shrink Small Outline Package (QSOP) 20-Lead Shrink Small Outline Package (QSOP) Evaluation Board with AD8331ARQ 32-Lead Lead Frame Chip Scale Package (LFCSP) 32-Lead Lead Frame Chip Scale Package (LFCSP) 32-Lead Lead Frame Chip Scale Package (LFCSP) 28-Lead Thin Shrink Small Outline Package (TSSOP) 28-Lead Thin Shrink Small Outline Package (TSSOP) 28-Lead Thin Shrink Small Outline Package (TSSOP) Evaluation Board with AD8332ARU 64-Lead Lead Frame Chip Scale Package (LFCSP) 64-Lead Lead Frame Chip Scale Package (LFCSP) 64-Lead Lead Frame Chip Scale Package (LFCSP) Evaluation Board with AD8334ACP Z = RoHS Compliant Part. ©2003–2016 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D03199-0-5/16(I) Rev. I | Page 55 of 55 Package Option RQ-20 RQ-20 RQ-20 CP-32-7 CP-32-7 CP-32-7 RU-28 RU-28 RU-28 CP-64-1 CP-64-1 CP-64-1