Final Electrical Specifications LT5504 800MHz to 2.7GHz RF Measuring Receiver January 2002 U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ The LT®5504 is an 800MHz to 2700MHz monolithic integrated measuring receiver, capable of detecting a wide dynamic range RF signal from –75dBm to +5dBm. The logarithm of the RF signal is precisely converted into a linear DC voltage. The LT5504 consists of RF/IF limiters, an LO buffer amplifier, a limiting mixer, a 3rd-order 450MHz integrated low pass filter, RF/IF detectors and an output interface. The ultrawide dynamic range is achieved by simultaneously measuring the RF signal and a downconverted IF signal obtained using the on-chip mixer and an external local oscillator. The RF- and IF-detected signals are summed to generate an accurate linear DC voltage proportional to the input RF voltage (or power) in dB. The output is buffered with a low output impedance driver. RF Frequency Range: 800MHz to 2.7GHz Ultra Wide Dynamic Range: 80dB Over Full Frequency Range and Over Temperature Wide Power Supply Range: 2.7V to 5.25V Low Supply Current: 14.7mA at 3V Shutdown Current: 0.2µA 8-Lead MS0P Package U APPLICATIO S ■ ■ ■ ■ ■ RSSI Measurements Receive AGC Transmit Power Control ASK and Envelope Demodulation GSM/TDMA/CDMA/WCDMA , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO C2 1nF 3V C1 100pF Output Voltage and Slope Variation vs RF Input Power VCC LT5504 2.0 RF DETECTOR IF DETECTOR ••• IF DETECTOR 4 OUTPUT R2 200Ω C3 10pF R1 82Ω VOUT (V) RF+ fRF = 900MHz fIF = 240MHz AVERAGE SLOPE:23mV/dB 1.6 2 1.2 0 0.8 –2 0.4 –4 SLOPE VARIATION (dB) VOUT RF INPUT 6 2.4 RF – ENABLE LO EN GND 5504 TA01a LO INPUT 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) 0 –6 10 5504 TA01b 5504i Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 1 LT5504 U W W W ABSOLUTE AXI U RATI GS U W U PACKAGE/ORDER I FOR ATIO (Note 1) Power Supply Voltage ............................................ 5.5V VOUT, EN ................................................................ 0,VCC LO Input Power .................................................... 6dBm RF Input Power Differential (50Ω, 5.5V) ............. 24dBm RF Input Power Single-Ended (50Ω, 5.5V) ......... 18dBm Operating Ambient Temperature ..............–40°C to 85°C Storage Temperature Range ..................–65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C ORDER PART NUMBER TOP VIEW VCC RF+ RF – GND 1 2 3 4 8 7 6 5 VCC VOUT LO EN LT5504EMS8 MS8 PACKAGE 8-LEAD PLASTIC MSOP MS8 PART MARKING LTGP TJMAX = 150°C, θJA = 160°C/W Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER TA = 25°C. VCC = 3V, PLO = –10dBm, unless otherwise noted. (Notes 2, 3) CONDITIONS MIN TYP MAX UNITS RF Input fRF Frequency Range 800 to 2700 Input Impedance Note 6 DC Voltage Internally Biased 1.7 MHz V LO Input fLO PLO Frequency Range 850 to 3100 Input Return Loss Internally Matched DC Voltage Internally Biased LO Power LO to RF Leakage 900MHz 1.9GHz 2.5GHz MHz 14 dB 0.82 V –16 to –8 dBm –50 –45 –40 dBc dBc dBc 50 to 450 MHz IF Frequency fIF Frequency Output Voltage at fRF = 900MHz, fLO = 1140MHz Linear Dynamic Range (Note 4) 66 Output Voltage Input = –70dBm Input = –20dBm Input = 0dBm Average Slope Input from –50dBm to –20dBm 16 75 dB 0.4 1.6 2.1 V V V 23 mV/dB 72 dB 0.35 1.52 1.9 V V V Output Voltage at fRF = 1900MHz, fLO = 2140MHz Linear Dynamic Range (Note 4) 60 Output Voltage Input = –70dBm Input = –20dBm Input = 0dBm Average Slope Input from –50dBm to –20dBm 16 23 mV/dB 5504i 2 LT5504 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER TA = 25°C. VCC = 3V, PLO = –10dBm, unless otherwise noted. (Notes 2, 3) CONDITIONS MIN TYP MAX UNITS 58 70 dB 0.3 1.45 1.8 V V V Output Voltage at fRF = 2500MHz, fLO = 2260MHz Linear Dynamic Range (Note 4) Output Voltage Input = –70dBm Input = –20dBm Input = 0dBm Average Slope Input from –50dBm to –20dBm 16 23 mV/dB 400 µA Output Interface Current Drive Capability Output Noise Spectral Density At 100KHz At 10MHz 3.9 0.32 µV/√Hz µV/√Hz Output Response Time (Note 5) RF Input Pin from No Signal to 0dBm 200 ns Turn ON Time (Note 5) 400 ns Turn OFF Time (Note 5) 4 µs Input Resistance 30 kΩ Power Up/Down tON Enable Turn ON Voltage (Note 7) 0.6 • VCC V Disable Turn OFF Voltage (Note 7) 0.4 • VCC V Power Supply VCC Supply Voltage ICC Supply Current 14.7 22 mA Shutdown Current 0.2 30 µA Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Tests are performed as shown in the configuration of Figure 5. Note 3: Specifications over the –40°C to 85°C temperature range are guaranteed by design, characterization and correlation with statistical process controls. 2.7 5.25 V Note 4: The Linear Dynamic Range is defined as the range over which the output slope is at least 50% of the average slope from –50dBm to –20dBm. Note 5: The output voltage is settled to the full specification within 1dB. Note 6: Refer to Figure 1 and Applications Information. Note 7: Refer to Pin Functions description. 5504i 3 LT5504 U W TYPICAL PERFOR A CE CHARACTERISTICS Output Voltage vs RF Input Power and Frequency Supply Current vs Supply Voltage and Temperature Power Up Response Time 20 2.4 fIF = 240MHz SUPPLY CURRENT (mA) 2.0 fRF = 900MHz fRF = 1.9GHz 1.2 fRF = 2.5GHz 0.8 16 VOUT 1V/DIV TA = 25°C 14 ENABLE 1V/DIV 10 0.4 8 0 10 OFF 2.5 3.5 4.0 4.5 SUPPLY VOLTAGE (V) 3.0 5.0 5504 G03 2.4 fIF = 240MHz AVERAGE SLOPE: 23mV/dB 2.0 VOUT (V) 0 fRF = 1.9GHz 2 0 1.2 TA = 85°C –2 0.8 –2 50% VARIATION OR SLOPE = 11.5mV/dB TA = 25°C TA = –40°C Output Voltage and Slope Variation vs RF Input Power and Temperature 0.8 TA = 85°C –2 TA = –40°C –4 0.4 TA = 25°C 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) TA = –40°C –2 10 0 TA = –40°C 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) 2.4 4 fIF = 70MHz 2 1.6 240MHz 0 1.2 70MHz 0.8 –6 10 Output Voltage and Slope Variation vs RF Input Power and Supply Voltage 6 400MHz 0 5504 G06 fRF = 1.9GHz AVERAGE SLOPE: 23mV/dB 2.0 VOUT (V) 0 1.2 –4 0.4 fIF = 240MHz –2 –4 0.4 6 fRF = 1.9GHz fIF = 240MHz 2.0 4 VCC = 5.25V 2 1.6 VCC = 5.25V 0 1.2 VCC = 2.7V 0.8 0.4 –2 VCC = 2.7V SLOPE VARIATION (dB) TA = –40°C –2 TA = 25°C SLOPE VARIATION (dB) VOUT (V) 4 2 TA = 25°C 2.4 SLOPE VARIATION (dB) 1.6 TA = 85°C 0.8 Output Voltage and Slope Variation vs RF Input Power and IF Frequency 6 fRF = 1.9GHz fIF = 240MHz 2.0 AVERAGE SLOPE: 23mV/dB 0 1.2 5504 G05 5504 G04 2.4 2 TA = 25°C TA = –40°C 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) 10 4 1.6 –4 0.4 0 fRF = 2.5GHz fIF = 240MHz 2.0 AVERAGE SLOPE: 23mV/dB 4 TA = 25°C 6 2.4 SLOPE VARIATION (dB) 1.6 fRF = 900MHz 6 fRF = 900MHz fIF = 240MHz AVERAGE SLOPE: 23mV/dB SLOPE VARIATION (dB) SLOPE VARIATION (dB) 4 fRF = 2.5GHz –6 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) Output Voltage and Slope Variation vs RF Input Power and Temperature Output Voltage and Slope Variation vs RF Input Power and Temperature Output Slope Variation vs RF Input Power and Frequency –4 2µs/DIV 5504 G02 5504 G01 2 5.5 VOUT (V) 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) 6 ON TA = –40°C 12 VOUT (V) VOUT (V) 1.6 VCC = 3V RF INPUT POWER = 0dBm TA = 85°C 18 –4 fIF = 400MHz 0 –6 10 5504 G07 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) 0 –6 10 5504 G08 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) 0 –6 10 5504 G09 5504i 4 LT5504 U W TYPICAL PERFOR A CE CHARACTERISTICS Output Voltage and Slope Variation vs RF Input Power and Temperature Output Voltage and Slope Variation vs RF Input Power and Temperature 6 1.6 2 TA = 25°C TA = –40°C 0 1.2 0.8 TA = 85°C –2 TA = 25°C 0.4 –4 1.6 VOUT (V) 4 fRF = 1.9GHz fIF = 400MHz 2.0 AVERAGE SLOPE: 23mV/dB TA = 25°C 0 2 TA = –40°C 0 1.2 TA = 85°C –2 0.8 TA = 25°C –4 0.4 TA = –40°C TA = –40°C 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) 4 –6 10 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) 0 SLOPE VARIATION (dB) fRF = 1.9GHz fIF = 70MHz 2.0 AVERAGE SLOPE: 23mV/dB Output Response Time 6 2.4 SLOPE VARIATION (dB) VOUT (V) 2.4 VOUT 1V/DIV PULSED RF 900MHz 0dBm 1V/DIV –6 10 100ns/DIV 5504 G12 5504 G11 5504 G10 U U U PI FU CTIO S VCC (Pins 1, 8 ): Power Supply Pins. These pins must be tied together at the part as close as possible, and should be decoupled using 1000pF capacitors. RF+ (Pin 2): Positive RF Input Pin. EN (Pin 5): Enable Pin. The on/off threshold voltage is about VCC/2. When the input voltage is higher than 0.6 • VCC, the circuit is completely turned on. When the input voltage is less than 0.4 • VCC, the circuit is turned off. RF– (Pin 3): Negative RF Input Pin. LO (Pin 6): Local Oscillator Input Pin. GND (Pin 4): Ground Pin. VOUT (Pin 7): Output Pin. W BLOCK DIAGRA VCC VCC 1 8 7 VOUT + DET DET LIMITING MIXER RF+ 2 RF– 3 RF LIMITER DET DET LPF IF LIMITER LO BUFFER ••• IF LIMITER ENABLE 6 4 5 LO GND EN 5504 BD 5504i 5 LT5504 U U W U APPLICATIO S I FOR ATIO The LT5504 consists of the following sections: RF/IF limiters, limiting mixer, RF/IF detectors, LO buffer amplifier, 3rd-order integrated low pass filter (LPF), output interface and bias circuitry. An RF signal ranging from 800MHz to 2.7GHz is detected by the RF and IF detectors using a proprietary technique. The down-converted IF signal is band limited by the onchip LPF, reducing broadband noise, and thus an ultrawide dynamic range signal can be measured. The RF measuring receiver is essentially a logarithmic voltage detector. The measured output voltage is directly proportional to the RF signal voltage. An internal temperature compensation circuit results in a highly temperature-stable output voltage. RF Limiter The differential input impedance of the RF limiter is shown in Figure 1. A 1:1 input transformer can be used to achieve 50Ω broadband matching with an 82Ω shunt resistor (R1) at the inputs as shown in Figure 5. MATCHING NETWORK CS1 3.3pF RF INPUT TO RF + LSH 3.3nH CS2 3.3pF TO RF – 5504 F02 Figure 2. RF Input Matching Network at 1900MHz Figure 3 shows the output voltage vs RF input power response for these two input terminations. The voltage gain of the single-ended-to-differential conversion circuit is: GAIN = 20 • LOG RIN = 3dB, 50 where RIN = 100Ω is the narrow band input impedance. Thus, the output voltage curve in this case is shifted to the left by about 3dB. Table 1. The Component Values of Matching Network LSH, CS1 and CS2 63.56Ω –j98.05Ω 900.00MHz 2: 26.69Ω –j42.90Ω 1.90GHz 3: 28.88Ω –j27.76Ω 2.50GHz fIF (MHz) LSH(nH) CS1/CS2(pF) 900 12.0 3.9 1900 3.3 3.3 2500 2.7 2.2 2700 2.4 1.5 1: 2.5 3 fRF = 1.9GHz 2.0 1 WITH SINGLE-ENDED-TODIFFERENTIAL INPUT CIRCUIT START: 100MHz STOP:3GHz 5504 F01 VOUT (V) 2 1.5 1.0 WITH 1:1 INPUT TX Figure 1. Differential RF Input Impedance 0.5 The 1:1 RF input transformer can also be replaced with a narrow band single-ended-to-differential conversion circuit using three discrete elements as shown in Figure 2. Their nominal values are listed in Table 1. Due to the parasitics of the PCB, these values may require adjustment. 0 –80 –70 –60 –50 –40 –30 –20 –10 PIN (dBm) 0 10 5504 F03 Figure 3. The Output Voltage vs RF Input Power 5504i 6 LT5504 U U W U APPLICATIO S I FOR ATIO Limiting Mixer and LPF The amplified RF signal is down-converted using the limiting mixer and LO signal. The resulting signal is filtered by the 3rd-order, 450MHz, integrated low pass filter (LPF). Only the desired IF signal is passed to the IF limiters for further detection. Any other mixing products, including LO feedthrough, are much reduced to maximize sensitivity. The receiver’s sensitivity is thus defined by the LPF bandwidth. IF Limiter The IF signal is then amplified through the multiple limiter stages for further signal detection. All DC offsets, including LO signal self-mixing, are eliminated by an internal DC offset cancellation circuit. Nevertheless, care should be taken in component placement and in PCB layout to minimize LO coupling to the RF port. Output Interface The output interface of the LT55O4 is shown in Figure 4. The output currents from the RF and IF detectors are summed and converted into an output voltage, VOUT. The maximum charging current available to the output load is about 400µA. An internal compensation capacitor CC is used to guarantee stable operation for a large capacitive output load. The slew rate is 80V/µs and the small signal output bandwidth is approximately 5MHz when the output is resistively terminated. When the output is loaded with a large capacitor CL, the slew rate is limited to 400µA/CL. For example, the slew rate is reduced to 4V/ µs when CL = 100pF. VCC + – OUTPUT CURRENTS FROM RF AND IF DETECTORS 400µA CC VOUT 5504 F04 Figure 4. Simplified Circuit Schematic of the Output Interface Applications The LT5504 can be used as a self-standing signal strengthmeasuring receiver (RSSI) for a wide range of input signals from – 75dBm to +5dBm, for frequencies from 800MHz to 2.7GHz. The LT5504 can be used as a demodulator for AM and ASK modulated signals with data rates up to 5MHz. Depending on specific application needs, the RSSI output can be split into two branches, providing AC coupled data output, and DC coupled, RSSI output for signal strength measurements and AGC. Refer to Figure 5. The LT5504 can also be used as a wide range RF power detector for transmit power control. U TYPICAL APPLICATIO S C2 100pF C1 RF INPUT 100pF C4 1nF VCC R3 10k C3 1nF 1 R1 82Ω T1 TOKO 617DB-1022 8 VCC VCC LT5504 2 7 RF + VOUT 3 4 RF – LO GND EN JUMPER R2 200Ω VOUT 6 LO INPUT 5 R5 500k C7 100pF R4 20k 5504 F04 Figure 5. LT5504 Evaluation Board Circuit Schematic Figure 6.Component Side Silkscreen of Evaluation Board 5504i 7 LT5504 U TYPICAL APPLICATIO Figure 7. Component Side Layout of Evaluation Board Figure 8.Bottom Side Silkscreen of Evaluation Board Figure 9. Bottom Side Layout of Evaluation Board U PACKAGE DESCRIPTIO MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660) 0.889 ± 0.127 (.035 ± .005) 5.23 (.206) MIN 3.2 – 3.45 (.126 – .136) 0.42 ± 0.04 (.0165 ± .0015) TYP 0.254 (.010) 3.00 ± 0.102 (.118 ± .004) (NOTE 3) 8 7 6 5 3.00 ± 0.102 (.118 ± .004) NOTE 4 4.88 ± 0.1 (.192 ± .004) DETAIL “A” 0.52 (.206) REF 0° – 6° TYP GAUGE PLANE 0.65 (.0256) BSC 0.53 ± 0.015 (.021 ± .006) RECOMMENDED SOLDER PAD LAYOUT DETAIL “A” 1 1.10 (.043) MAX 2 3 4 0.86 (.34) REF 0.18 (.077) NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX SEATING PLANE 0.22 – 0.38 (.009 – .015) 0.65 (.0256) BCS 0.13 ± 0.05 (.005 ± .002) MSOP (MS8) 1001 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT5500 1.8GHz to 2.7GHz Receiver Front End LNA with Dual Gain Setting, Double Balanced Mixer, Internal LO Buffer, 1.8V to 5.25V LT5502 400MHz Quadrature IF Demodulator with RSSI IF Frequency Range, 70MHz to 400MHz, 84dB Limiting IF Gain 90db Linear RSSI Range, 1.8V to 5.25V Supply LT5503 1.2GHz to 2.7GHz Direct IQ Modulator and Mixer 1.8V to 5.25V Supply Range, 28mA Supply Current, 4-Step Output Power Control LTC5505 RF Power Detector in SOT-23 Internal Schottky Diode with Buffer, >40dB Dyamic Range, Low 0.5mA Supply Current, 2.7V ≤ VCC ≤ 6V, 300MHz to 3GHz 5504i 8 Linear Technology Corporation LT/TP 0102 1.5K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2002