AD8347-EVAL Analog Devices Inc, AD8347-EVAL Datasheet
AD8347-EVAL
Specifications of AD8347-EVAL
Related parts for AD8347-EVAL
AD8347-EVAL Summary of contents
Page 1
... IF broadband demodulators RF instrumentation Satellite modems GENERAL DESCRIPTION 1 The AD8347 is a broadband direct quadrature demodulator with RF and baseband automatic gain control (AGC) amplifiers suitable for use in many communications receivers, performing quadrature demodulation directly to baseband frequencies. The input frequency range is 800 MHz to 2.7 GHz. The outputs can ...
Page 2
... AD8347 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 Functional Block Diagram .............................................................. 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 5 ESD Caution.................................................................................. 5 Pin Configuration and Function Descriptions............................. 6 Typical Performance Characteristics ............................................. 8 RF Amp and Demodulator ......................................................... 8 Baseband Output Amplifiers .................................................... 11 RF Amp/Demod and Baseband Output Amplifiers .............. 12 Equivalent Circuits..................................................................... 14 Theory of Operation ...
Page 3
... V − 1.3 S 0.4 AD8347 Unit GHz dBm V V ° p-p dBm dBm dBm dBm dBm dBm MHz degree p p-p mV p-p Ω dB MHz p-p dBc dBc μ ...
Page 4
... AD8347 Parameter CONTROL INPUT/OUTPUTS VCMO Input Gain Control Input Bias Current Offset Input Overriding Current VREF Output RESPONSE FROM RF INPUT TO FINAL BB AMP Gain @ V = 0.2 V VGIN Gain @ V = 1.2 V VGIN Gain Slope Gain Intercept LO/RF INPUT LOIP Input Return Loss RFIP Input Return Loss ...
Page 5
... Exposure to absolute 68°C/W maximum rating conditions for extended periods may affect 150°C device reliability. −40°C to +85°C −65°C to +150°C 300°C Rev Page AD8347 ...
Page 6
... In AGC mode, connect this pin directly to VAGC. LOIN LOIP 1 28 VPS1 COM1 2 27 IOPN 3 QOPN 26 IOPP QOPP 4 25 VCMO 5 QAIN 24 COM3 IAIN 6 23 AD8347 COM3 QMXO 7 22 TOP VIEW (Not to Scale) IMXO 8 21 VPS3 VDT1 COM2 9 20 RFIN 10 VAGC 19 RFIP 11 18 VDT2 VPS2 12 ...
Page 7
... VREF IMXO IOFS IAIN VREF VREF VCMO PHASE SPLITTER 2 DET 1 DET 2 VREF VDT1 VAGC VDT2 QMXO QOFS QAIN Figure 3. Block Diagram Rev Page AD8347 IOPP IOPN 4 3 VCMO 5 LOIN 1 PHASE SPLITTER 1 LOIP 28 COM3 7 VCMO COM2 9 23 COM3 27 COM1 25 26 QOPP QOPN ...
Page 8
... AD8347 TYPICAL PERFORMANCE CHARACTERISTICS RF AMP AND DEMODULATOR –40° +85° +25° – +25°C A –10 –15 – +85°C A –25 –30 –35 0.2 0.3 0.4 0.5 0.6 0.7 0.8 V (V) VGIN Figure 4. Gain and Linearity Error vs 1900 MHz –40° +25° +85° –40°C ...
Page 9
... S A 1000 1200 1400 1600 1800 2000 2200 2400 2600 RF FREQUENCY (MHz) Figure 14. IIP3 vs 0 MHz LO VGIN 2.7V –40° 5V +85° 2.7V +85° 5V –40° 5V +25° 2.7V +25° BASEBAND FREQUENCY (MHz) Figure 15. IIP3 vs 1 1900 MHz BB VGIN LO AD8347 100 ...
Page 10
... AD8347 –10 –12 – 5V +85° – 2.7V +85° –18 – 5V +25°C – – 5V –40° – 2.7V –28 – 2.7V, – –40°C A – BASEBAND FREQUENCY (MHz) Figure 16. IIP3 vs 0 BB, VGIN 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 RF FREQUENCY (MHz) Figure 17 ...
Page 11
... V = 2.7V, MEAN + 2.7V, MEAN 5V, MEAN 5V, MEAN + –2 σ 2.7V, MEAN – S – 5V, MEAN – S –6 0.5 1.0 1.5 2.0 2.5 V (V) VCMO Figure 25. Common-Mode Output Offset Voltage vs. V Temperature = 25°C (σ Standard Deviation) AD8347 = 100 σ σ 3.0 3.5 , VCMO ...
Page 12
... AD8347 RF AMP/DEMOD AND BASEBAND OUTPUT AMPLIFIERS –40° 2. –40° +25° 2. +25° +85° 2. +85° –5 0.2 0.3 0.4 0.5 0.6 0.7 0.8 V (V) VGIN Figure 26. Voltage Gain vs 1900 MHz, F VGIN LO 2.5 2.0 1.5 1.0 0 +25° –0.5 –1.0 –1 +85° ...
Page 13
... V Figure 34. AGC Voltage and Mixer Output Level vs. RF Input Power –40 –30 –20 – Figure 35. Supply Current vs. Temperature Rev Page AD8347 T = –40° +25° +85° –40°C A –50 –40 –30 –20 – INPUT POWER (dBm 1900 MHz, F ...
Page 14
... AD8347 EQUIVALENT CIRCUITS VPS1 LOIN LOIP COM1 Figure 36. Circuit A VPS3 IOPP , IOPN, QOPP , QOPN, IMXO, QMXO COM3 Figure 37. Circuit B VPS3 VCMO CURRENT MIRROR COM3 Figure 38. Circuit C PHASE SPLITTER CONTINUES Rev Page VPS3 IAIN QAIN COM3 Figure 39. Circuit D VPS2 RFIP RFIN COM2 Figure 40 ...
Page 15
... VPS3 VREF COM3 Figure 42. Circuit G VPS3 ENBL COM3 Figure 43. Circuit H Figure 44. Circuit I Rev Page AD8347 VPS3 VAGC COM3 ...
Page 16
... GAIN VGIN 17 CONTROL INTERFACE The AD8347 is a direct I/Q demodulator usable in digital wireless communication systems including cellular, PCS, and digital video receivers signal in the frequency range of 800 MHz to 2,700 MHz is directly downconverted to the I and Q components at baseband using a local oscillator (LO) signal at the same frequency as the RF signal. ...
Page 17
... The reference voltage (VREF) of 1.0 V, that serves as the common-mode reference for the baseband circuits, is made available for external use. The VREF pin should be decoupled with a 0.1 μF capacitor to ground. Rev Page AD8347 ...
Page 18
... AD8347 APPLICATIONS BASIC CONNECTIONS The basic connections for operating the AD8347 are shown in Figure 46. The device is powered through three power supply pins: VPS1, VPS2, and VPS3. These pins supply current to different parts of the overall circuit. VPS1 and VPS2 power the local oscillator (LO) and RF sections, respectively, while VPS3 powers the baseband amplifiers. Connect all of these pins to the same supply voltage ...
Page 19
... OPERATING THE VGA IN AGC MODE Although the VGA can be driven by an external source such as a DAC, the AD8347 has an on-board sum of squares detector to allow the AD8347 to operate in an automatic leveling mode. Due to the nature of the detector, an input signal with a higher peak-to-average ratio causes the AGC loop to settle with a higher mixer output peak-to-peak voltage ...
Page 20
... AD8347 +V + 0.1 μ F 0.1 μ F 0.1 μ F 100pF 100pF VPS1 VPS2 2 12 AD8347 BIAS 15 CELL ENBL C1 100pF RFIN 10 R1 200 Ω RFIP 11 C2 100pF RF INPUT VGIN GAIN 17 CONTROL INTERFACE Figure 48. Adjusting AGC Level to Increase Baseband Amplifier Output Swing CHANGING THE AGC SETPOINT The AGC circuit can be easily set up to level at voltages higher than the nominal 24 mV p-p, as shown in Figure 48 ...
Page 21
... In Figure 49, the output common-mode levels at Pin 2 (V pin) of the AD8132s are set OCM by the AD8347’s VREF (approximately 1 V). The output common- mode levels can also be externally set, using, for example, the reference voltage from an ADC. R19A 4.99k Ω ...
Page 22
... Feedthrough of the LO signal to the RF input port results in self-mixing of the LO signal. This produces a dc component at the mixer output that is frequency dependent. The AD8347 includes an internal circuit that actively nulls any dc offsets that appear at the mixer output. The dc bias level of the mixer output (which should ideally equal V ...
Page 23
... EVALUATION BOARD Figure 53 shows the schematic of the AD8347 evaluation board. Note that uninstalled components are indicated with the open designation. The board is powered by a single supply in the range of 2 5.5 V. Table 4 details the various configuration options of the evaluation board. TP1 +V S R35 0Ω ...
Page 24
... AD8347 Figure 55. Layout of Component Side Figure 54. Silkscreen of Component Side Rev Page Figure 56. Layout of Circuit Side ...
Page 25
... R40 to VREF. R35, R36, R37, R38 Baseband Amplifier Output Series Resistors. SW1 Device Enable. When in Position A, the ENBL pin is connected to +V AD8347 is in operating mode. In Position B, the ENBL pin is grounded, putting the device in power-down mode. and the S Rev Page AD8347 ...
Page 26
... PIN 1 0.15 0.05 COPLANARITY ORDERING GUIDE Model Temperature Range AD8347ARU −40°C to +85°C AD8347ARU-REEL7 −40°C to +85°C AD8347ARUZ 1 −40°C to +85°C 1 AD8347ARUZ-REEL7 −40°C to +85°C AD8347-EVAL Pb-free part. 9.80 9.70 9. 4.50 4.40 4. 0.65 BSC 1.20 MAX 0.30 ...
Page 27
... NOTES Rev Page AD8347 ...
Page 28
... AD8347 NOTES © 2005 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. C02675-0-10/05(A) Rev Page ...