HMC714LP5

HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz Features • Crest Factor (Peak-to-Average Power Ratio) Measurement • Envelope-to-Average Power Ratio Measurement • Dual channel and channel difference output ports • Excellent Channel Matching and Channel Isolation • Supports Controller Mode[1] • ± 1 dB Detection Accuracy to 3.9 GHz • Input Dynamic Range -55 dBm to +15 dBm • +5V Operation from -40° C to +85° C • Excellent Temperature Stability • Integrated Temperature Sensor • Power-Down Mode • 32 Lead 5x5mm SMT Package: 25mm2 12 POWER DETECTORS - SMT • RF Signal Wave Shape & Crest Factor Independent Typical Applications • Log -> Root - Mean - Square (RMS) Conversion • Transmitter Power Control • Receiver Automatic Gain Control • Antenna VSWR Monitor • Received Signal Strength Indication (RSSI) • Transmitter Signal Strength Indication (TSSI) • Dual Channel wireless infrastructure radio Functional Diagram [1] For more information regarding controller mode operation, please contact your Hittite sales representative or email sales@hittite.com 12 - 114 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz General Description The HMC714LP5E is a dual-channel RMS power detector designed for high accuracy RF power signal measurement and control applications over the 0.1 to 3.9 GHz frequency range. The device can be used with input signals having RMS values from -55 dBm to +15 dBm referenced to 50 Ω and large crest factors with no accuracy degradation. Each RMS detection channel is fully specified for operation up to 3.9 GHz, over a wide dynamic range of 70 dB. The HMC714LP5E operates from a single +5V supply and provides two linear-in-dB detection outputs at the RMSA and RMSB pins with scaled slopes of 37 mV/dB. The RMSA and RMSB channel outputs provide RMS detection performance in terms of dynamic range, logarithmic linearity and temperature stability similar to Hittite’s HMC614LPE RMS Detector. The RMSA and RMSB outputs provide a read of average input signal power, or true-RMS power. Frequency detection up to 5.8 GHz is possible, with excellent channel matching of less than 0.5 dB (for the single-ended configuration), over a wide range of input frequencies and with low temperature drift. The HMC714LP5E also provides “channel difference” output ports via pins OUTP and OUTN, permitting measurements of the input signal power ratio between the two power detection channels. These outputs may be used in single-ended or differential configurations. An input voltage applied to the VLVL input pin is used to set the common mode voltage reference level for OUTP and OUTN. On the Hittite evaluation board, the VLVL pin is shorted to VREF2 output to provide a nominal bias voltage of 2.5V; but any external bias voltage may be used to set VLVL. The HMC714LP5E also features INSA and INSB pins which provide a measurement of instantaneous signal power normalized to average power level in each channel. Reading both the INSA/INSB and RMSA/RMSB output voltage signals provides a very informative picture of the RF input signal; providing peak power, average power, peak-toaverage power, and RF wave shape. The device also includes a buffered PTAT temperature sensor output with a temperature scaling factor of 2.2 mV/°C yielding a typical output voltage of 600 mV at 0°C. The HMC714LP5E operates over the -40 to +85C temperature range, and is available in a compact, 32-lead 4x4 mm leadless QFN package 12 POWER DETECTORS - SMT 12 - 115 Electrical Specifi cations I, TA = +25°C, VCCA = VCCB = VCCBIAS = 5V, CINT = 0.1 μF Parameter Dynamic Range (± 1 dB measurement error) Input Signal Frequency Differential Input Configuration, Channel A Differential Input Configuration, Channel B Input Signal Frequency Single-Ended Input Configuration, Channel A Single-Ended Input Configuration, Channel B Channel Isolations Input Signal Frequency Input A to Input B Isolation (Baluns Macom ETC1-1-13 at both channels) Input A to RMS B Isolation (PIN B = - 45 dBm, RMS B = RMSBINB ±1 dB) Input B to RMSA Isolation (PINA = - 45 dBm, RMSA = RMSAINA ±1 dB) Input A to RMS B Isolation (PIN B = - 40 dBm, RMS B = RMSBINB ±1 dB) Input B to RMSA Isolation (PINA=-40 dBm, RMSA=RMSAINA ±1 dB) 100 72 500 70 60+ 60+ 900 69 56 58 1900 53 46 46 2200 51 44 44 3000 56 47 48 47 43 39 28 3500 48 3900 47 MHz dB dB dB dB dB 100 68 68 100 70 70 500 68 69 900 62 62 900 69 69 1900 72 71 2200 71 71 3000 66 64 3500 47 45 3900 42 41 MHz dB dB MHz dB dB Typ. Typ. Typ. Typ. Typ. Typ. Typ. Typ. Units 1800 ± 300 71 71 2200 ± 300 69 69 3600 ± 300 61 61 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz Electrical Specifi cations II, TA = +25°C, VCCA = VCCB = VCCBIAS = 5V, CINT = 0.1 μF Parameter Typ. Typ. Typ. Typ. Typ. Typ. Typ. Typ. Units Deviation vs Temperature: (Over full temperature range -40°C to 85°C. Deviation is measured from reference, which is CW input at 25°C Differential Input Interface with 1:1 Balun Transformer (over full input frequency range) Wideband Single-Ended Input Interface suitable for input signal frequencies below 1000 MHz Tuned Single-Ended Input Interface Suitable for input signal frequencies above 1000 MHz ± 0.6 ± 0.5 ± 0.6 dB dB dB Modulation Deviation (Deviation measured from reference, which is measured with CW input at equivalent input signal power, VTGT=2V) Input Signal Frequency 256QAM (2 Mbps, 8dB Crest Factor) 100 -0.13 -0.3 -0.5 500 -0.1 -0.2 -0.5 900 -0.1 -0.2 -0.4 1900 -0.1 -0.2 -0.4 2200 -0.1 -0.2 -0.3 3000 -0.1 -0.2 -0.4 3500 -0.3 -0.2 -0.4 3900 -0.3 -0.2 -0.4 MHz mV/dB dBm dBm 12 POWER DETECTORS - SMT WCDMA Single Carrier (Test Model 1 with 64DPCH) WCDMA 2 Carrier (Test Model 1 with 64DPCH) Modulation Deviation (Deviation measured from reference, which is measured with CW input at equivalent input signal power, VTGT=1V) Input Signal Frequency 256QAM (2 Mbps, 8dB Crest Factor) WCDMA Single Carrier (Test Model 1 with 64DPCH) WCDMA 2 Carrier (Test Model 1 with 64DPCH) 100 0.1 -0.1 -0.1 500 0.1 -0.1 -0.1 900 0.1 -0.1 -0.1 1900 0.1 -0.1 -0.1 2200 0.1 -0.1 -0.1 3000 0.1 -0.1 -0.1 3500 -0.2 -0.1 -0.1 3900 -0.1 -0.1 -0.1 MHz dB dB dB Differential Input Configuration Logarithmic Slope and Intercept Input Signal Frequency Logarithmic Slope Logarithmic Intercept Max. Input Power at +-1dB Error Min. Input Power at +-1dB Error 100 37.3 -70 12 -56 500 37.1 -70 14 -55 900 37 -69.5 13 -56 1900 36 -72 15 -56 2200 36 -71.5 15 -56 3000 36.1 -68.5 13 -52 3500 36.2 -68.5 -5 -52 3900 38.2 -64 -8 -49 MHz mV/dB dBm dBm dBm Single Ended Input Configuration Logarithmic Slope and Intercept Input Signal Frequency Logarithmic Slope Logarithmic Intercept Max. Input Power at +-1dB Error Min. Input Power at +-1dB Error 100 38.2 -67 14 -56 900 37.9 -67.5 6 -56 1800 ± 300 36.6 -67 15 -56 2200 ± 300 35.4 -67 15 -54 3600 ± 300 36.8 -64.5 12 -49 MHz mV/dB dBm dBm dBm iPAR Feature: INS[A,B] outputs follow Amplitude Modulated Envelope Power, scaled to Average (RMS) Signal Power INS[A,B] and IREF[A,B] are measured with Rext = 3.9 kΩ and 50 kΩ active scope probe IREF[A,B] Output Voltage INS[A,B] Output Voltage, with CW Input Signal (EAR = 1: Reference Condition)[1] INS[A,B] Scaling Factor (SF) with VTGT = 2V INS[A,B] Scaling Factor (SF) with VTGT = 1V INS[A,B] Output: Variation over Temperature (-40C to 85C) INS[A,B] Output: 3 dB Video BW [1] EAR: Amplitude Modulated Envelope Signal Power-to-Average (RMS) Signal Power Ratio; EAR = 1 for CW signals 1.6 1.6 190 95 ±2 35 V V mV mV % MHz 12 - 116 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz RMS [A,B] Error vs. Pin with Different Modulations @ 1900 MHz, VTGT= 1V 2 1.5 1 ERROR (dB) 0.5 0 -0.5 -1 -1.5 -2 -60 CW WCDMA 1 Carrier WCDMA 2 Carrier 256QAM RMS [A,B] vs. Pin with Different Modulations @ 1900 MHz, VTGT= 1V 4 3.5 3 RMSA (RMSB) (V) 2.5 2 1.5 1 0.5 0 -60 Ideal CW WCDMA1 Carrier WCDMA 2 Carrier 256QAM -50 -40 -30 -20 -10 0 10 -50 -40 -30 -20 -10 0 10 12 POWER DETECTORS - SMT 12 - 117 INPUT POWER (dBm) INPUT POWER (dBm) Logarithmic Error wrt to CW Response @ 1900 MHz for Different Modulation Schemes, VTGT= 1V 1.2 1 0.8 0.6 0.4 WCDMA 1 Carrier WCDMA 2 Carrier 256QAM Logarithmic Error wrt to CW Response @ 1900 MHz for Different Modulation Schemes, VTGT= 2V 2 WCDMA 1 Carrier WCDMA 2 Carrier 256QAM 1.5 ERROR (dB) ERROR (dB) 1 0.5 0.2 0 -60 0 -60 -50 -40 -30 -20 -10 0 10 -50 -40 -30 -20 -10 0 10 INPUT POWER (dBm) INPUT POWER (dBm) Table 3: Electrical Specifi cations III , HMC714LP5E Differential Confi guration, TA=25°C, VCCA = VCCB = VCCBIAS = 5V, Cint = 0.1 uF, unless otherwise noted Parameter Differential Input Configuration Input Network Return Loss Input Resistance between INPA and INNA Input Resistance between INPB and INN B Input Voltage Range RMSOUT [A,B] Output Output Voltage Range Openloop Output Voltage Range Source/Sink Current Compliance Output Slew Rate (rise/fall) RL = 1kOhm, CL = 4.7pF [2] RMS-VSET disconnected for control applications Measured with 900 MHz input RF signal at -30 dBm power With CINT=0, Cofs=0 0.4 to 3.2 0.4 to Vcc-1 10/1.1 110/6 V V mA 10 V/sec 6 Conditions Min. Typ. Max. Units up to 2.5 GHz[1] Between pins 2 and 3 Between pins 6 and 7 VDIFFINA = VINPA - VINNA and VDIFFINB = VINPB -VINNB > 10 220 220 2.25 dB Ohms Ohms V F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz Table 3: Electrical Specifi cations III , HMC714LP5E Differential Confi guration, TA=25°C, VCCA = VCCB = VCCBIAS = 5V, Cint = 0.1 uF, unless otherwise noted Parameter VSET [A,B] Outputs Input Voltage Range [2] Input Resistance OUTP and OUTN Outputs Output Voltage Range Openloop Output Voltage Range RL=1kOhm, CL=4.7pF [2] OUTP-FBKA and OUTN-FBKB disconnected for control applications Measured with 900 MHz input RF signal at -30 dBm power 1 to 3.9 0.1 to Vcc-0.9 20/4.2 V V mA For control applications with nominal slope/intercept settings 0.4 to 3.2 15 V kOhm Conditions Min. Typ. Max. Units 12 POWER DETECTORS - SMT Source/Sink Current Compliance VLVL , Common Mode Reference Level for OUT[P,N] Voltage Range Input Resistance VREF2 , Voltage Reference Output Output Voltage Temperature Sensitivity Source/Sink Current Compliance VREF3 , Voltage Reference Output Output Voltage Temperature Sensitivity Source/Sink Current Compliance TEMP, Temperature Sensor Output Output Voltage Temperature Sensitivity Source/Sink Current Compliance ENX Logic Input, Power Down Control Input High Voltage Input Low Voltage Input Capacitance Power Supply Supply Voltage Supply Current with no input power 115 mA nominal at -40°C; 153mA nominal at 85°C 128 mA nominal at -40°C; 166mA nominal at 85°C 4.5 5 138 5.5 V mA 0.5 0.7*VCC 0.3*VCC V V pF measured at 0°C 0.6 2.2 1.7 / 0.5 V mV/°C mA 2.94 0.15 0.15 / 0.7 V mV/°C mA 2.43 0.15 5.5 / 2.6 V mV/°C mA OUT[P,N]=FBK[A,B] 0 6 5 V kOhm Supply Current with 0dBm at one channel Supply Current with 0dBm at both channels Standby Mode Supply Current 150 mA 164 6.5 mA mA [1] Performance of differential input configuration is limited by the balun. Baluns used are M/A-COM ETC1-1-13 specified 4.5 MHz to 3000 MHz [2] For nominal slope/intercept setting, please see application section to change this range 12 - 118 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz RMSA & Error vs. Pin @ 100 MHz [1] 4 Ideal RMSA +25C RMSA +85C RMSA - 40C RMSB & Error vs. Pin @ 100 MHz [1] 4 3 2 ERROR (dB) RMSB (V) 1 3 4 Ideal RMSB +25C RMSB +85C RMSB - 40C 4 3 2 ERROR (dB) 1 3 RMSA (V) 2 0 -1 2 0 -1 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 0 -60 0 -60 12 POWER DETECTORS - SMT 12 - 119 INPUT POWER (dBm) INPUT POWER (dBm) RMSA & Error vs. Pin @ 500 MHz [1] 4 Ideal RMSA +25C RMSA +85C RMSA - 40C RMSB & Error vs. Pin @ 500 MHz [1] 4 3 2 ERROR (dB) RMSB (V) 1 3 4 Ideal RMSB +25C RMSB +85C RMSB - 40C 4 3 2 ERROR (dB) 1 3 RMSA (V) 2 0 -1 2 0 -1 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 0 -60 0 -60 -50 -40 -30 -20 -10 0 10 INPUT POWER (dBm) INPUT POWER (dBm) RMSA & Error vs. Pin @ 900 MHz [1] 4 Ideal RMSA +25C RMSA +85C RMSA - 40C RMSB & Error vs. Pin @ 900 MHz [1] 4 3 2 ERROR (dB) RMSB (V) 1 3 4 Ideal RMSB +25C RMSB +85C RMSB - 40C 4 3 2 ERROR (dB) 1 3 RMSA (V) 2 0 -1 2 0 -1 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 0 -60 0 -60 INPUT POWER (dBm) INPUT POWER (dBm) [1] CW Input Waveform F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz RMSA & Error vs. Pin @ 1900 MHz [1] 4 Ideal RMSA +25C RMSA +85C RMSA - 40C RMSB & Error vs. Pin @ 1900 MHz [1] 4 3 2 ERROR (dB) RMSB (V) 1 3 4 Ideal RMSB +25C RMSB +85C RMSB - 40C 4 3 2 ERROR (dB) 1 3 RMSA (V) 2 0 -1 2 0 -1 1 -2 ERR +25C ERR +85C ERR - 40C 1 12 POWER DETECTORS - SMT -3 -4 0 -60 -50 -40 -30 -20 ERR +25C ERR +85C ERR - 40C -2 -3 -4 0 -60 -50 -40 -30 -20 -10 0 10 -10 0 10 INPUT POWER (dBm) INPUT POWER (dBm) RMSA & Error vs. Pin @ 2200 MHz [1] 4 Ideal RMSA +25C RMSA +85C RMSA - 40C RMSB & Error vs. Pin @ 2200 MHz [1] 4 4 Ideal RMSB +25C RMSB +85C RMSB - 40C 4 3 2 ERROR (dB) 1 3 RMSA (V) 2 ERROR (dB) RMSB (V) 3 2 0 2 0 -1 1 ERR +25C ERR +85C ERR - 40C -2 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 0 -60 -50 -40 -30 -20 -10 0 10 -4 0 -60 -50 -40 -30 -20 -10 0 10 INPUT POWER (dBm) INPUT POWER (dBm) RMSA & Error vs. Pin @ 3000 MHz [1] 4 Ideal RMSA +25C RMSA +85C RMSA - 40C RMSB & Error vs. Pin @ 3000 MHz [1] 4 3 2 ERROR (dB) RMSB (V) 1 3 4 Ideal RMSB +25C RMSB +85C RMSB - 40C 4 3 2 ERROR (dB) 1 3 RMSA (V) 2 0 -1 2 0 -1 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 0 -60 0 -60 INPUT POWER (dBm) INPUT POWER (dBm) [1] CW Input Waveform 12 - 120 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz RMSA & Error vs. Pin @ 3500 MHz [1] 4 Ideal RMSA +25C RMSA +85C RMSA - 40C RMSB & Error vs. Pin @ 3500 MHz [1] 4 3 2 ERROR (dB) RMSB (V) 1 3 4 Ideal RMSB +25C RMSB +85C RMSB - 40C 4 3 2 ERROR (dB) 1 3 RMSA (V) 2 0 -1 2 0 -1 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 0 -60 0 -60 12 POWER DETECTORS - SMT 12 - 121 INPUT POWER (dBm) INPUT POWER (dBm) RMSA & Error vs. Pin @ 3900 MHz [1] 4 Ideal RMSA +25C RMSA +85C RMSA - 40C RMSB & Error vs. Pin @ 3900 MHz [1] 4 3 2 ERROR (dB) RMSB (V) 1 3 4 Ideal RMSB +25C RMSB +85C RMSB - 40C 4 3 2 ERROR (dB) 1 3 RMSA (V) 2 0 -1 2 0 -1 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 1 ERR +25C ERR +85C ERR - 40C -2 -3 -4 -50 -40 -30 -20 -10 0 10 0 -60 0 -60 INPUT POWER (dBm) INPUT POWER (dBm) OUT [P,N] & Error vs. Pin @ 100 MHz, INPA Power Swept, INPB Fixed Power @ -25 dBm [1] 4 Out N 3 OUT[P,N](V) Out P 2 4 OUT [P,N] & Error vs. Pin @ 500 MHz, INPA Power Swept, INPB Fixed Power @ -25 dBm [1] 4 Out N 3 OUT[P,N](V) ERROR (dB) Out P 2 ERROR (dB) 4 2 0 2 0 1 Out P Err +25C Out P Err +85C Out P Err -40C Out N Err +25C Out N Err +85 C Out N Err -40C -2 1 Out P Err +25C Out P Err +85C Out P Err -40C Out N Err +25C Out N Err +85 C Out N Err -40C -2 0 -60 -50 -40 -30 -20 -10 0 10 -4 0 -60 -50 -40 -30 -20 -10 0 10 -4 INPUT POWER (dBm) INPUT POWER (dBm) [1] CW Input Waveform F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz OUT [P,N] & Error vs. Pin @ 1900 MHz, INPA Power Swept, INPB Fixed Power @ -25 dBm [1] 4 Out N 2 OUT[P,N] (V) ERROR (dB) 3 Out P 2 ERROR (dB) 4 OUT [P,N] & Error vs. Pin @ 900 MHz, INPA Power Swept, INPB Fixed Power @ -25 dBm [1] 4 Out N 3 OUT[P,N](V) Out P 4 2 0 2 0 1 12 POWER DETECTORS - SMT Out P Err +25C Out P Err +85C Out P Err -40C Out N Err +25C Out N Err +85 C Out N Err -40C -2 1 Out P Err +25C Out P Err +85C Out P Err -40C Out N Err +25C Out N Err +85 C Out N Err -40C -2 0 -60 -50 -40 -30 -20 -10 0 10 -4 0 -60 -50 -40 -30 -20 -10 0 10 -4 INPUT POWER (dBm) INPUT POWER (dBm) OUT [P,N] & Error vs. Pin @ 2200 MHz, INPA Power Swept, INPB Fixed Power @ -25 dBm [1] 4 Out N 3 OUT[P,N](V) Out P 2 4 OUT [P,N] & Error vs. Pin @ 3000 MHz, INPA Power Swept, INPB Fixed Power @ -25 dBm [1] 4 Out N 3 OUT[P,N](V) ERROR (dB) Out P 2 ERROR (dB) 4 2 0 2 0 1 Out P Err +25C Out P Err +85C Out P Err -40C Out N Err +25C Out N Err +85 C Out N Err -40C -2 1 Out P Err +25C Out P Err +85C Out P Err -40C Out N Err +25C Out N Err +85 C Out N Err -40C -2 0 -60 -50 -40 -30 -20 -10 0 10 -4 0 -60 -50 -40 -30 -20 -10 0 10 -4 INPUT POWER (dBm) INPUT POWER (dBm) OUT [P,N] & Error vs. Pin @ 3500 MHz, INPA Power Swept, INPB Fixed Power @ -25 dBm [1] 4 Out N 3 OUT[P,N](V) Out P 2 4 OUT [P,N] & Error vs. Pin @ 3900 MHz, INPA Power Swept, INPB Fixed Power @ -25 dBm [1] 4 Out N 3 OUT[P,N] (V) ERROR (dB) Out P 2 ERROR (dB) 4 2 0 2 0 1 Out P Err +25C Out P Err +85C Out P Err -40 C Out N Err +25C Out N Err +85C Out N Err -40 C -2 1 0 -60 -50 -40 -30 -20 -10 0 10 -4 Out P Err +25C Out P Err +85C Out P Err -40 C Out N Err +25C Out N Err +85C Out N Err -40 C -2 0 -60 -50 -40 -30 -20 -10 0 10 -4 INPUT POWER (dBm) INPUT POWER (dBm) [1] CW Input Waveform 12 - 122 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz RMSA-RMSB, Channel Matching vs. Pin over Temperature @ 500 MHz [1][2] 60 40 RMSA-RMSB (mV) 20 0 -20 -40 -60 -55 +25C +85C -40C RMSA-RMSB, Channel Matching vs. Pin over Temperature @ 100 MHz [1][2] 60 40 RMSA-RMSB (mV) 20 0 -20 -40 -60 -55 +25C +85C -40C -45 -35 -25 -15 -5 5 15 -45 -35 -25 -15 -5 5 15 12 POWER DETECTORS - SMT 12 - 123 Input Power (dBm) Input Power (dBm) RMSA-RMSB, Channel Matching vs. Pin over Temperature @ 900 MHz [1][2] 60 40 RMSA-RMSB (mV) 20 0 -20 -40 -60 -55 +25C +85C -40C RMSA-RMSB, Channel Matching vs. Pin over Temperature @ 1900 MHz [1][2] 60 40 RMSA-RMSB (mV) 20 0 -20 -40 -60 -55 +25C +85C -40C -45 -35 -25 -15 -5 5 15 -45 -35 -25 -15 -5 5 15 Input Power (dBm) Input Power (dBm) RMSA-RMSB, Channel Matching vs. Pin over Temperature @ 2200 MHz [1][2] 60 40 RMSA-RMSB (mV) 20 0 -20 -40 -60 -55 +25C +85C -40C RMSA-RMSB, Channel Matching vs. Pin over Temperature @ 3000 MHz [1][2] 60 40 RMSA-RMSB (mV) 20 0 -20 -40 -60 -55 +25C +85C -40C -45 -35 -25 -15 -5 5 15 -45 -35 -25 -15 -5 5 15 Input Power (dBm) Input Power (dBm) [1] CW Input Waveform [2] Differential Input Configuration. Baluns selected for matching performance, mismatch between channels is limited by the input baluns. F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz RMSA-RMSB, Channel Matching vs. Pin over Temperature @ 3900 MHz [1][2] 80 60 RMSA-RMSB (mV) 40 20 0 -20 -40 -60 -80 -55 +25C +85C -40C RMSA-RMSB, Channel Matching vs. Pin over Temperature @ 3500 MHz [1][2] 80 60 RMSA-RMSB (mV) 40 20 0 -20 -40 +25C +85C -40C 12 POWER DETECTORS - SMT -60 -80 -55 -45 -35 -25 -15 -5 5 15 -45 -35 -25 -15 -5 5 15 Input Power (dBm) Input Power (dBm) Interference to an Input Signal (INB Power Fixed) with Interfering Signal on the other Channel (INA Power Swept) [1] 6 5 4 Error (dB) 3 2 1 0 -30 0.5GHz 0.9GHz 1.9GHz 2.2GHz 3.0GHz 3.9GHz Interference to an Input Signal (INA Power Fixed) with Interfering Signal on the other Channel (INB Power Swept) [1] 6 5 4 Error (dB) 3 2 1 0 -30 0.5GHz 0.9GHz 1.9GHz 2.2GHz 3.0GHz 3.9GHz Channel B fixed at -45dBm for fInput B Input B->Input A Channel Isolation/Interface Channel isolation/interference is grouped into two categories: On-chip inter-channel interference, and Off-chip inter-channel interference. Off-chip interference between channels should be considered, especially at small signal levels, since HMC714LP5E is capable of detecting a signal over a very wide dynamic range (70 dB+). There are two main mechanisms through which the interference between the channels may affect measurement accuracy. The first one is the direct coupling of the RF signal from one RF channel input to the other RF channel input. Baluns on the detector inputs usually contribute to inter-channel coupling, as does PC board design and the quality of the soldered connections. On-chip inter-channel interference, herein referred to as “input-output channel isolation”, usually manifests itself as drift on one detector output due to a relatively strong signal present at the other detector input. Quantitatively, the inputoutput channel isolation is defined as the difference between the input power levels at both channels when the interfering (higher power level) channel causes a 1 dB measurement drift in the interfered (lower power level) channel. Worst case channel interference occurs when one channel has an input signal level just over its detection threshold. Input-Output Channel isolation for HMC714LP5E is: 55+ dB input-output isolation at 900 MHz 45 dB input-output isolation up to 2.7 GHz 35 dB input-output isolation up to 5.8 GHz. If the same signal frequency is injected into both channels for this Input-Output Channel Isolation measurement, the interference will manifest as a phase delay. A slight offset in signal frequency between the two channels can be seen as a ripple at the output of the channel with the lower power level applied at its input. Peaks in the output ripple correspond to the worst-case phase shift for input-output interference. The frequency of the output ripple will be equal to the “beat” frequency between the two channels. The magnitude of the output ripple will depend on the integration and offset capacitors connected to CINT and COFS pins, respectively. The output ripple is reduced by increasing the value of the integration capacitance (CINT), thereby decreasing the integrator bandwidth. The data was collected using a 100kHz offset between the channels. 12 POWER DETECTORS - SMT FREQUENCY (GHz) Interference to an Input Signal (INB Power Fixed) with Interfering Signal on the other Channel (INA Power Swept) [1] 3 ERROR IN CHANNEL B (dB) 2.5 2 1.5 1 0.5 0 -30 0.5 GHz 0.9 GHz 1.9 GHz 2.7 GHz 3.9 GHz 5.8 GHz -25 -20 -15 -10 -5 0 5 10 15 CHANNEL A INPUT POWER (dBm) Interference to an Input Signal (INA Power Fixed) with Interfering Signal on the other Channel (INB Power Swept) [1] 3 ERROR IN CHANNEL A (dB) 2.5 2 1.5 1 0.5 0 -30 0.5 GHz 0.9 GHz 1.9 GHz 2.7 GHz 3.9 GHz 5.8 GHz -25 -20 -15 -10 -5 0 5 10 15 CHANNEL B INPUT POWER (dBm) 12 - 142 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz Confi guration for the Typical Application The RF inputs can be connected in either a differential or single-ended configuration: see “RF Input Interface” section for details on each input configuration. With the appropriate input tuning components, the part can provide the full performance with a single-ended input. The RMSA & RMSB output signals are typically connected directly to VSETA & VSETB inputs, providing a Pin->VRMS transfer characteristic slope of 36.5 mV/dBm at both channels; however the RMS output can be re-scaled to “magnify” a specific portion of the input sensing range, and to fully utilize the dynamic range of the RMS output. Refer to the section under the “log-slope and intercept” for details. The INSA & INSB pins are the instantaneous peak-to-average ratio (iPAR) outputs; on each detector. This iPAR measurement pulls it’s signal from the internals of the RMS detector, just before the RMS calculation is processed. Each iPAR output (INSA & INSB) produces a voltage signal which provides a direct read of the RF signal AM envelope. So between the simultaneous measurement of RMS power and iPAR on each power detector, a system can monitor average power, peak power, peak-to-average power, and the RF waveshape. See the section under “iPAR Envelope Power Normalized to Average Power” for application details. VTGT with a nominal value of 2V is typically generated from the VREF reference output of 3V; however the VTGT voltage can be adjusted to optimize measurement accuracy, especially when measurement at higher crest factors is important: see “Adjusting VTGT for greater precision” section for technical details. Due to part-to-part variations in log-slope and log-intercept, a system-level calibration is recommended to satisfy absolute accuracy requirements: refer to the “System Calibration” section for more details. The HMC714LP5E requires a single 5V supply connected to three pins: VCCA , VCCB, and VCCBIAS. Adequate power supply decoupling is required on these pins. The supply pins should be decoupled to ground using two parallel capacitors with the values shown in the application schematic. The capacitors should be placed close to the part (with the smaller value as close as possible to the supply pin) and must provide a low impedance path to RF GND over the entire input frequency range. 12 POWER DETECTORS - SMT 12 - 143 Temperature Sensor Interface The HMC714LP5E provides a buffered PTAT temperature sensor output that provides a temperature scaling factor of 2.2 mV/°C with a typical output voltage of 600 mV at 0°C. The output is capable of sourcing 1.5 mA. TEMP Output 0.85 0.8 0.75 TEMP (V) 0.7 0.65 0.6 0.55 0.5 -40 -30 -20 -10 TEMP Ideal 0 10 20 30 40 50 60 70 80 90 TEMPERATURE (Celcius) F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz RF Input Interface The INPA and INNA pins are differential inputs on one of two power detectors, which we will refer to as channel A. INPB and INNB pins are differential inputs on the other power detector, channel B. The inputs for both channels can be externally configured with differential or single-ended input. Power match components are placed on these input terminals, along with DC blocking capacitors. The coupling capacitor values also set the lower spectral boundary of the input signal bandwidth. The inputs can be reactively matched (refer to input return loss graphs), but a resistor network should be sufficient for good wideband performance. Differential Input Interface: 12 POWER DETECTORS - SMT The value of RD (=RDA=RDB) depends on the balun used; if the balun is 50Ω on both sides of the SE-Diff conversion, then RD where RM = the desired power match impedance in ohms. For RM = 50Ω, RD = 67Ω ≈ 68Ω Single-Ended Input Interface: Tuned SE-interface: for signal frequencies > 900MHz Choose L and C elements from the following graph for narrowband tuning of the SE-interface: R31/34 = 30Ω, R32/35 = 50Ω, C1/6 =1 nF R30/33 = 270Ω, Wideband SE-interface: for signal frequencies < 900 MHz R31/34 = 0Ω, R32/35 = OPEN, R1/R3 = 68Ω, R30/33 = Open C2, C5 is 1 nF decoupling caps. For wideband (un-tuned) input interfaces, choose the input decoupling capacitor values by first determining the lowest spectral component the power detector is required to sense, ƒL. Input decoupling capacitor value 1 ≈ p × f L × 3.2 farads, where ƒL is in Hertz. Ex. If the power detector needs to sense down to 10 MHz, the decoupling capacitor value should be 1/(π*10E6*3.2) = 10 nF A DC bias (Vcc-1.5V) is present on the INP[A,B] and IN[A,B] pins, and should not be overridden. F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com 12 - 144 HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz RF Input Interface (Continued) Tuning, Single Ended Interface: fc ± 300 MHz 10 9 TUNING CAPACITANCE (pF) 8 7 6 5 4 3 2 1 0 900 1400 1900 2400 2900 3400 FREQUENCY (MHz) 10 9 8 7 6 5 4 3 2 1 0 3900 TUNING INDUCTANCE (nH) 12 POWER DETECTORS - SMT 12 - 145 RMS Output Interface and Transient Response Output transient response is determined by the integration capacitances CINTA & CINTB and output load conditions. Using larger values of CINT will narrow the operating bandwidth of the integrator, resulting in a longer averaging time-interval and a more filtered output signal; however it will also slow the power detector’s transient response. A larger CINT value favors output accuracy over speed. For the fastest possible transient settling times, leave the CINT pins free of any external capacitance. This configuration will operate the integrator at its widest possible bandwidth, resulting in short averaging time-interval and an output signal with little filtering. Most applications will choose to have some external integration capacitance, maintaining a balance between speed and accuracy. Furthermore, error performance over crest factor is degraded when CINT is very small (for CINT < 100 pF). Modulation and deviation results in Electrical Specification Table 2 are provided with CINT = 0.1 uF. Start by selecting CINT using the following expression, and then adjust the value as needed, based on the application’s preference for faster transient settling or output accuracy. CINT = 1500 uF/(2*π *ƒlam), in Farads, where ƒlam = lowest amplitude-modulation component frequency in Hertz Example: when ƒlam = 10 kHz, CINT = 1500 μF/(2*π*1000) = 24E-9 Farads ~ 22 nF Table: Transient response vs. CINT capacitance: with COFS = 0 CINT 0 100 pF 1 nF 10 nF RMS Rise - Time over Dynamic Range Pin = 0 dBm 35 nsec 80 nsec 780 nsec 7.8 usec RMS Fall - Time Pin = -30 dBm 120 nsec 410 nsec 3.3 usec 32.4 usec Pin = -10 dBm 200 nsec 720 nsec 5.6 usec 54 usec Pin = 0 dBm 1.18 usec 1.26 usec 7 usec 66.4 usec Input signal is 1900 MHz CW-tone switched on and off RMS is loaded with 1kΩ, 4 pF, and VTGT = 2V, F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz RMS Output Interface and Transient Response (Continued) Transient response can also be slewed by the RMS output if it is excessively loaded: keep load resistance above 375Ω. An optimal load resistance of approximately 500Ω to 1kΩ will allow the output to move as quickly as it is able. For increased load drive capability, consider a buffer amplifier on the RMS output. Using an integrating amplifier on the RMS output allows for an alternative treatment for faster settling times. An external amplifier optimized for transient settling can also provide additional RMS filtering, when operating HMC714LP5E with a lower CINT capacitance value. Rise/Fall Characteristics, CINT = 0 pF Rise/Fall Characteristics, CINT = 10 nF 4 3.5 3 RMSOUT (V) 2.5 2 1.5 1 0.5 10 dBm 0 dBm -10 dBm -20 dBm -30 dBm 12 RMSOUT (V) 4 3.5 3 10 dBm 0 dBm -10 dBm -20 dBm -30 dBm POWER DETECTORS - SMT 2.5 2 1.5 1 0.5 0 0 0.5 1 1.5 TIME (usec) 2 2.5 3 0 0 50 100 150 200 250 TIME (usec) LOG-Slope and Intercept The HMC714LP5E provides for an adjustment of output scale by controlling the fraction of RMSA /RMSB that is fed-back to the setpoint interface at the VSETA /VSETB pins. Log-slope and intercept can be adjusted to “magnify” a specific portion of the input sensing range, and to fully utilize the dynamic range of the RMS output. A log-slope of 36.5 mV/dBm is set by connecting the RMSA /RMSB outputs directly to VSETA /VSETB pins using 0Ω resistors RFBK A and RFBKB. The log-slope is adjusted by using the appropriate resistors RFBK A , RFBKB, RSHUNTA , RSHUNTB on the RMSA /RMSB and VSETA /VSETB pins. Log-intercept is adjusted by applying a DC voltage to the VSETA /VSETB pins through resistors RSETA and RSETB . Due to the 15 kΩ input resistance at the VSETA /VSETB pins, moderately low resistance values should be used to minimize the scaling errors. Very low resistor values will reduce the load driving capabilities of RMSA /RMSB outputs while larger values will result in scaling errors and increase of the temperature errors because of the mismatch of the on-chip and external resistor temperature coefficients. Optimized slope = ß * log slope Optimized intercept = log intercept - (RFBK / RSET) * Vzc RFBK ß= RFBK // RSHUNT // RSET When RFBK = 0 Ohm to set RMS = VSET, then ß = 1 Note: Avoid excessive loading of the RMS output; keep CLOAD < 35 pF, and RLOAD > 375Ω F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com 12 - 146 HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz LOG-Slope and Intercept (Continued) Example: The logarithmic slope can be simply increased by choosing appropriate RFBK and RSHUNT values while not populating the RSET resistor on the evaluation board to keep the intercept at nominal value. Setting RFBK = 820Ω and RSHUNT = 2200Ω results in an optimized slope of: Optimized Slope = ß * log_slope = 1.42 * 36.5 mV / dB Optimized Slope = 52 mV / dB Slope Adjustment 4.5 4 3.5 RMSOUT (V) 3 2.5 2 1.5 1 0.5 0 -70 -60 -50 -40 Slope=36.2mV/dB Rset=open Rfbk=0ohm Rshunt=open Slope=51mV/dB Rset=open Rfbk=820ohm Rshunt=2200ohm High Slope Nominal 12 POWER DETECTORS - SMT 12 - 147 -30 -20 -10 0 10 INPUT POWER (dBm) Example: The logarithmic intercept can also be adjusted by choosing appropriate RFBK, RSHUNT, and RSET values while keeping the logarithmic slope at about 50mV/dB. Setting RFBK = 820 Ohm and RSHUNT = RSET = 4700Ω results in an optimized slope of: Optimized Slope = ß * log_slope = 1.4 * 36.5 mV / dB Optimized Intercept = log_intercept - RFBK * VZC RSET Optimized Intercept = log_intercept - 0.174 * VZC Optimized Slope = 51 mV / dB Intercept Adjustment 4.5 4 3.5 3 VOUT (V) RMS (V) 2.5 2 1.5 1 0.5 0 -60 -50 -40 -30 -20 -10 Vzc=0 Vzc=0.8 Vzc=1.6 Vzc=3.2 Vzc=-0.8 Vzc=-1.6 Vzc=-3.2 Rset=4700ohm Rfbk=820ohm Rshunt=4700ohm Intercept Adjustment (with Temp) 4.5 4 3.5 3 VSET=0V VSET=-1.6V +25C +85C -40C 2.5 2 1.5 1 0.5 VSET=1.6V 0 10 0 -60 -50 -40 -30 -20 -10 0 10 INPUT POWER (dBm) INPUT POWER (dBm) F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz iPAR – Envelope Power Normalized To Average Power The INSA and INSB are envelope detector outputs for A & B channels that provide a measurement of instantaneous signal power normalized average power. This feature is called Instantaneous Peak to Average Ratio (iPAR). The iPAR makes peak-to-average power comparisons immediately obvious. This simultaneous measurement of envelope power and average power in HMC714LP5E has two fundamental advantages over traditional methods of which employ two different power detectors working in parallel. • Both the iPAR and RMS detectors share the same measurement structures, and • Both the iPAR and RMS detectors share the same temperature compensation mechanisms. With traditional implementation of peak-to-average power detection, the dominant source of errors is due to the uncorrelated measurement deviations between the two separate detectors. Both detectors in the HMC714LP5E share the same circuits (INSA-RMSA pair and INSB -RMSB pair), so any deviations, however small, are fully correlated. The iPAR feature can be configured to provide two major functions: 12 POWER DETECTORS - SMT 1. A measurement of instantaneous signal power normalized to average power In this most basic measurement mode, INSA (INSB) output is terminated to ground using an external resistor which forms an output buffer with the internal transistor Q1 connected in emitter-follower configuration. With Rext = 3.9 kOhm (R20 and R12 on the evaluation board for A & B channels), INSA (INSB) output can track the input envelope up to a modulation bandwidth of 35 MHz at which point the output swing drops by 50%. For an unmodulated input signal with f>>35 MHz, the INSA (INSB) output will provide a constant value of approximately 1.6V indicating that the instantaneous power is equal to the average power. The INSA (INSB) output voltages linearly follow the instantaneous power levels at the detector input with the transfer gain scaled by an external voltage applied to VTGT (pin 28). For a nominal voltage of 2V on VTGT the scaling factor of the INSA (INSB) output is 200 mV. INS[A ,B] = IREF[A ,B] + SF*(EAR[A ,B] - 1) where IREF[A ,B] = (VCC[A ,B]*REXT) /( 3*(REXT+65 Ohm)) ≈ 1.6 V (for VCC = 5V, REXT = 2 kΩ) where EAR[A ,B] = input signal RF AM envelope-to-average power ratio on channel [A,B] and SF = the scaling factor set by an external voltage applied to VTGT (200 mV when VTGT = 2.0V) For example, the INSA (INSB) voltage will drop to 1.4 V (1.6-0.2V) when the input power instantaneously drops to zero, and will increase to 2.2V (1.6+0.2*3) when the input power instantaneously increases to 4 times the average power. With lower VTGT values the scaling factor also decreases, allowing INSA (INSB) to linearly track larger swings of input power. iPAR Output & Input RF Signal Envelope vs. Time for an Input Crest Factor of 9.03 dB @ 1900 MHz [2] 2.25 IPAR Output INS [A,B] Output vs. Instantaneous Input Power (Normalized to Average Power) 3 2.8 IPWR OUTPUT (V) 2.6 2.4 2.2 2 1.8 1.6 1.4 0 2 =Pin/Pav*0.2+(1.6-0.2) IPWR Output VTGT = 2V =Pin/Pav*0.1+(1.6-0.1) IPWR Output VTGT = 1V 1.5 INPUT RF SIGNAL ENVELOPE (V) IPWR(t) = (VTGT/10)x(Pin(t)/Pavg)+(1.6-(Vtgt/10)) 1.75 INS [A,B] (V) 1 1.25 0.5 0.75 0 0.25 Input RF Signal Envelope -0.5 1 2 3 Time (usec) 4 5 0 4 6 8 10 INSTANTANEOUS INPUT POWER (NORMALIZED TO AVERAGE POWER) 12 12 - 148 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz PAR – Envelope Power Normalized To Average Power (Continued) The INSA (INSB) output is highly independent from input signal frequency, input average power, and temperature. Proprietary design techniques assure very little part-to-part variation and maintain a very high degree of match between channels. 2. A measurement of peak-power normalized to average power To measure peak power, a peak-hold mechanism is required at the INSA (INSB) output. The peak-hold circuit can be as simple as an RC combination on the INSA (INSB) pin. In this configuration, peak excursions of the input signal is stored as a peak voltage on the external Cext capacitor. Rext is used to set the quiescent bias point of Q1, and together with Cext will for a time-constant for the peak-hold function. The larger Cext is the longer the peakdetector will “remember” the largest signal excursion; conversely a smaller value of Cext will result in a shorter memory, and less filtering. The value of Rext for this “peak-power” mode of the iPAR function should be much larger than the value used for the iPAR mode described previously (instantaneous power tracking mode) to extend the RextCext time-constant. INS[A ,B] = IREF[A ,B] + SF*(PAR[A ,B] - 1) where IREF[A ,B] = VCC[A ,B] / 3 + 0.15V ≈ 1.82V (for VCC = 5V, REXT = 500 kΩ) where PAR[A ,B] = input signal peak-to-average ratio on channel [A,B] and SF = the scaling factor set by an external voltage applied to VTGT (150 mV when VTGT = 2.0V) The graphs below describes the INSA (INSB) peak-hold levels as a function of input peak-to-average ratio (PAR) and also crest factor. Note how the voltage applied at VTGT affects the INSA (INSB) reading. The voltage applied to the VTGT pin also has a secondary effect on crest-factor performance. The VTGT signal optimizes internal bias points for measurement accuracy at higher crest factors: refer to the section under “Adjusting VTGT for greater precision” for a 12 POWER DETECTORS - SMT 12 - 149 iPAR Feature Peak-to-Average Power Detection Confi guration (REXT = 500Ω, CEXT = 100 nF) 3.4 3.2 3 2.8 INSA (V) INSA Linear Fit iPAR Feature Peak-to-Average Power Detection Confi guration vc Crest Factor (CEXT = 100 nF) 3.4 3.2 3 2.8 INSA (V) 2.6 2.4 2.2 Single Tone (CW) Inputs VTGT=2V Rext=100kohm VTGT=2V Rext=500kohm VTGT=1V Rext=500kohm 2.6 VTGT=2V 256QAM (1Mbps) Crest Factor~7.8dB 2.4 2.2 2 1.8 Single Tone (CW) Inputs VTGT=1V 2 1.8 1.6 1 2 3 4 5 6 7 8 9 10 11 12 1.6 2 3 4 5 6 7 8 9 10 11 INPUT CREST FACTOR (dB) 12 13 14 PEAK TO AVERAGE POWER RATIO (PAR) F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz PAR – Envelope Power Normalized To Average Power (Continued) full description on crest factor optimization. iPAR Reference Outputs: IREFA & IREFB HMC714LP5E also provides two reference voltage outputs, IREFA (pin 26) and IREFB (pin 15) for A & B channels, which when used with the INSA /INSB outputs allows cancellation of temperature and supply related variations of the INSA /INSB DC offsets. INSA /INSB DC offsets are equal to the IREFA /IREFB reference voltages, and these levels corresponds to the envelope-to-average ratio (EAR) or peak-to-average ratio (PAR) of an unmodulated carrier (CWtone crest factor = 3 dB). For the best cancellation of the effects of temperature and supply voltage on INSA /INSB DC offsets, load both the INSA /INSB and IREFA /IREFB outputs with an equivalent RC network. 12 POWER DETECTORS - SMT Propagation Delay of INSA & INSB The proper operation of the iPAR feature depends on the proper settling of the RMS outputs because both the iPAR feature and the RMS detection feature share the same internal structures. After internal mechanisms of the detector have settled, the RMS outputs (RMSA & RMSB) provide a reading of input average power while iPAR outputs (INSA & INSB) provides the instantaneous (or peak) power value of the input signal. There is of course some finite propagation delay from the instant of input power change to the change of INSA (INSB). That propagation delay is defined by the external capacitor, Cext. The figure illustrates the propagation delay from a 900 MHz, 6-tone (multi-carrier) input signal at -10 dBm average power to the INSA output of HMC714LP5E. As illustrated, the propagation delay is 26 nsec with the detector configured with the wideband, single-ended input interface. The use of the differential input interface with the balun increases the propagation delay to 37 nsec under similar test conditions. Propagation Delay with Wideband Single Ended Input Itnerface 0.2 0.15 Input Signal Envelope (V) 0.1 0.05 0 -0.05 -0.1 -0.15 -0.2 -150 -100 -50 0 50 100 150 200 26nS 2.85 2.49 2.14 1.78 INSA (V) 1.42 1.07 0.71 0.36 0 250 Vpd (Vdc) Standby Mode The ENX can be used to force the power detector into a low-power standby mode. In this mode, the entire power detector is powered-down. As ENX is deactivated, power is restored to all of the circuits. There is no memory of previous conditions. Coming-out of stand-by, CINT and COFS capacitors will require recharging, so if large capacitor values have been chosen, the wake-up time will be lengthened. DC Offset Compensation Loop Internal DC offsets, which are input signal dependant, require continuous cancellation. Offset cancellation is a critical function needed for maintenance of measurement accuracy and sensitivity. The DC offset cancellation loop performs this function, and its response is largely defined by the capacitance off. Setting DC offset cancellation, loop bandwidth strives to strike a balance between offset cancellation accuracy, and loop response time. A larger value of COFS results in a more precise offset cancellation, but at the expense of a slower offset cancellation response. A smaller value of COFS tilts the performance trade-off towards a faster offset cancellation response. The optimal loop bandwidth setting will allow internal offsets to be cancelled at a minimally acceptable speed. 12 - 150 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz DC Offset Compensation Loop (Continued) DC Offset Cancellation Loop Bandwith ≈ 1 π(500)(COFS + 20 x 1012) Hz For example: loop bandwidth for DC cancellation with COFS = 1nF, bandwidth is ~62 kHz Note: The measurement error produced by internal DC offsets cannot be measured repeatably at any single operating point, in terms of input signal frequency and level. Measurement error must be calculated to a best fit line, over the entire range of input signal (again, in terms of signal level and frequency). Adjusting VTGT for Greater Precision There are two competing aspects of performance, for which VTGT can be used to set a preference. Depending on which aspect of precision is more important to the application, the VTGT pin can be used to find a compromise between two sources of RMS output error: internal DC offset cancellation error and deviation at high crest factors (>12dB). • Increasing VTGT input voltage will reduce the effect of internal DC offsets, but deviation at high crest factors will increase slightly. A 50% increase in VTGT should produce an 18% improvement in RMS precision due to a reduction in internal DC offsets effects. • Decreasing VTGT input voltage will reduce errors at high crest factors, but internal DC offsets will have more of an effect on measurement accuracy. If input signal crest factor is not expected to exceed 10dB, you can improve RMS precision by increasing VTGT voltage. Keep in mind that changing VTGT also adjusts the log-intercept point, which shifts the “input dynamic range”. The best set-point for VTGT will be the lowest voltage that still maintains the “input dynamic range” over the required range of input power. This new VTGT set-point should optimize the amount of DC offset related errors. If error performance at high crest factors requires optimization, set VTGT for the maximum tolerable error at the highest expected crest factor. Increasing VTGT beyond that point will unnecessarily compromise internal DC offset cancellation performance. After changing VTGT, re-verify that the “input dynamic range” still covers the required range of input power. VTGT should be referenced to VREF for best performance. It is recommended to use a temperature stable DC amplifier between VTGT and VREF to create VTGT > VREF. The VREF pin is a temperature compensated voltage reference output, only intended for use with VTGT. 12 POWER DETECTORS - SMT 12 - 151 RMS Output Error vs. Crest Factor 0 RMSA/RMSB ERROR (dB) -0.5 -1 -1.5 VTGT infl uence on DC offset compensation VGTG 1.0 V 1.5 V 2.0 V 3.0 V Error due to internal DC offsets nominal + 0.2 dB nominal + 0.1 dB nominal 7.nominal + 0.06 dB nominal + 0.1 dB -2 -2.5 -3 VTGT=0.5V VTGT=1V VTGT=2V VTGT=3V 3.5 V 0 2 4 6 8 10 12 14 CREST FACTOR (dB) F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz System Calibration Due to part-to-part variations in log-slope and log-intercept, a system-level calibration is recommended to satisfy absolute accuracy requirements. When performing this calibration, choose at least two test points: near the top-end and bottom-end of the measurement range. It is best to measure the calibration points in the regions (of frequency and amplitude) where accuracy is most important. Derive the log-slope and log-intercept, and store them in non-volatile memory. Calibrate iPAR scaling by measuring the peak-to-average ratio of a known signal. For example if the following two calibration points were measured at 2.35 GHz: With Vrms = 2.34V at Pin= -7dBm, and Vrms=1.84V at Pin= -16dBm Now performing a power measurement: Vrms measures 2.13V [Measured Pin] = [Measured Vrms]*SCC + ICC [Measured Pin] = 2.13*18.0 – 49.12 = -10.78dBm An error of only 0.22dB 12 POWER DETECTORS - SMT Slope Calibration Constant = SCC SCC = (-16+7)/(1.84-2.34) = 18 dB/V Intercept Calibration Constant = ICC ICC = Pin – SCC*Vrms = -7 – 18.0 * 2.34 = -49.12dBm Factory system calibration measurements should be made using an input signal representative of the application. If the power detector will operate over a wide range of frequencies, choose a central frequency for calibration. Layout Considerations • Mount RF input coupling capacitors close to the IN+ and IN- pins. • Solder the heat slug on the package underside to a grounded island which can draw heat away from the die with low thermal impedance. The grounded island should be at RF ground potential. • Connect power detector ground to the RF ground plane, and mount the supply decoupling capacitors close to the supply pins. Defi nitions: • Log-slope: slope of PIN –> VRMS transfer characteristic. In units of mV/dB • Log-intercept: x-axis intercept of PIN –> VRMS transfer characteristic. In units of dBm. • RMS Output Error: The difference between the measured PIN and actual PIN using a line of best fit. [measured_PIN] = [measured_VRMS] / [best-fit-slope] + [best-fit-intercept], dBm • Input Dynamic Range: the range of average input power for which there is a corresponding RMS output voltage with “RMS Output Error” falling within a specific error tolerance. • Crest Factor: Peak power to average power ratio for time-varying signals. 12 - 152 F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com HMC714LP5 / 714LP5E v05.0309 DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz Notes: 12 POWER DETECTORS - SMT F or price, delivery, and to place orders, please contact Hittite Microwave Corporation: 20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com 12 - 153