LT5534 50MHz to 3GHz RF Power Detector with 60dB Dynamic Range FEATURES DESCRIPTION RF Frequency Range: 50MHz to 3GHz n Linear Dynamic Range: 60dB n Exceptional Accuracy over Temperature and Power Supply n Fast Transient Response: 38ns Full-Scale Settling Time n Single 2.7V to 5.25V Supply n Low Supply Current: 7mA n Shutdown Current: 0.1µA n Tiny 6-Lead SC70 Package The LT®5534 is a 50MHz to 3GHz monolithic RF power detector capable of measuring RF signals over a 60dB dynamic range. The RF signal in a decibel scale is precisely converted into DC voltage on a linear scale. The 60dB input dynamic range is achieved using cascaded RF detectors and RF limiters. Their outputs are summed to generate an accurate log-linear DC voltage proportional to the input RF signal in dB. The output is buffered with a low output impedance driver. The LT5534 delivers superior temperature stability (typical output variation within ±1dB over the full temperature range). The output responds in less than 40ns to a large RF input signal. n APPLICATIONS n n n n L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. RF RSSI and ACC RF Power Control CATV Power Detection Optical Receiver Gain Control TYPICAL APPLICATION Output Voltage vs RF Input Power 50MHz to 3GHz RF Power Detector 3V ENABLE DET DET DET VOUT RF EN GND 5534 TA01 VOUT VOUT (V) RF INPUT 47Ω DET 3 VCC = 3V AT 900MHz 2 1.6 1 1.2 0 0.8 –1 TA = 25°C TA = 85°C TA = –40°C 0.4 0 –60 –50 –40 –30 –20 –10 RF INPUT POWER (dBm) LINEARITY ERROR (dB) DET 2.0 VCC LT5534 1nF 2.4 100pF 0.1µF –2 0 –3 5534 TA01b 5534fc 1 LT5534 ABSOLUTE MAXIMUM RATINGS (Note 1) PIN CONFIGURATION Power Supply Voltage...............................................5.5V Enable Voltage......................................................0V, VCC RF Voltage (+10dBm Equivalent)...............................±1V Operating Ambient Temperature Range.... –40°C to 85°C Storage Temperature Range.................... –65°C to 125°C Lead Temperature (Soldering, 10 sec)................... 300°C TOP VIEW EN 1 6 RF GND 2 5 GND VOUT 3 4 VCC SC6 PACKAGE 6-LEAD PLASTIC SC70 TJMAX = 125°C, θJA = 256°C/W ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT5534ESC6#PBF LT5534ESC6#TRPBF LBGD 6-Lead Plastic SC70 –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ ELECTRICAL CHARACTERISTICS CC = 3V, EN = 3V, TA = 25°C, source impedance = 50Ω, unless otherwise V noted. Test circuit shown in Figure 1. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS RF Input Frequency Range 50 to 3000 MHz Input Impedance 2 kΩ –58 to +2 dBm fRF = 50MHz RF Input Power Range Dynamic Range (Note 3) ±3dB Linearity Error, TA = –40°C to 85°C Output Slope Output Variation vs Temperature PIN = –48dBm to –14dBm, TA = –40°C to 85°C 60 dB 44 mV/dB 0.007 dB/°C –60 to 0 dBm fRF = 900MHz RF Input Power Range Dynamic Range (Note 3) ±3dB Linearity Error, TA = –40°C to 85°C Output Slope Output Variation vs Temperature PIN = –48dBm to –14dBm, TA = –40°C to 85°C 60 dB 41 mV/dB 0.008 dB/°C –63 to –2 dBm fRF = 1900MHz RF Input Power Range Dynamic Range (Note 3) ±3dB Linearity Error, TA = –40°C to 85°C Output Slope 61 31 Output Variation vs Temperature PIN = –48dBm to –14dBm, TA = –40°C to 85°C Output Intercept 50Ω External Termination, TA = –40°C to 85°C 36.6 dB 43 0.012 –70 –64 mV/dB dB/°C –58 dBm fRF = 2500MHz RF Input Power Range Dynamic Range (Note 3) –63 to –3 ±3dB Linearity Error, TA = –40°C to 85°C 60 dBm dB 5534fc 2 LT5534 ELECTRICAL CHARACTERISTICS CC = 3V, EN = 3V, TA = 25°C, source impedance = 50Ω, unless otherwise V noted. Test circuit shown in Figure 1. (Note 2) PARAMETER CONDITIONS MIN TYP Output Slope Output Variation vs Temperature PIN = –48dBm to –14dBm, TA = –40°C to 85°C MAX UNITS 35 mV/dB 0.025 dB/°C Output Interface Output DC Voltage No RF Input Signal 0 142 380 mV Output Impedance 32 Ω Output Bandwidth 30 MHz Full-Scale Setting Time Input from No Signal to –2dBm, to 90% 38 Sinking/Sourcing ns 10/200 mA/µA VCC = 3V, EN = 3V, TA = 25°C, unless otherwise noted. Test circuit shown in Figure 1. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS Power Up/Down Turn-On Time 200 ns Turn-Off Time 800 ns EN = High (On) 0.9 V EN = Low (Off) 0.6 V Power Supply Supply Voltage 2.7 Supply Current EN = High Shutdown Current EN = Low Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: Specifications over the –40°C to 85°C temperature range are assured by design, characterization and correlation with statistical process control. Output Voltage vs Frequency 50MHz 1.9GHz 2.5GHz 1.2 0.8 0 –70 –60 VCC = 3V TA = 25°C 0 –50 –40 –30 –20 –10 RF INPUT POWER (dBm) 5534 G01 10 µA 2.0 3 VCC = 3V AT 50MHz 2 900MHz 1 0 2.5GHz –1 1.9GHz –2 0.4 0.1 Output Voltage vs RF Input Power 2.4 VOUT (V) VOUT (V) 1.6 2 900MHz mA –3 –70 1.6 1 1.2 0 0.8 –1 TA = 25°C TA = 85°C TA = –40°C 0.4 –60 0 –50 –40 –30 –20 –10 RF INPUT POWER (dBm) 5534 G02 0 –60 –50 –40 –30 –20 –10 RF INPUT POWER (dBm) LINEARITY ERROR (dB) 2.0 50MHz LINEARITY ERROR (dB) 2.4 VCC = 3V TA = 25°C 9 (Test circuit shown in Figure 1) Linearity Error vs Frequency 3 V 7 Note 3: The linearity error is calculated by the difference between the incremental slope of the output and the average output slope from –48dBm to –14dBm. The dynamic range is defined as the range over which the linearity error is within ±3dB. TYPICAL PERFORMANCE CHARACTERISTICS 2.8 5.25 5 –2 0 –3 5534 G03 5534fc 3 LT5534 TYPICAL PERFORMANCE CHARACTERISTICS (Test circuit shown in Figure 1) VOUT Variation vs RF Input Power Output Voltage vs RF Input Power 3 3 VCC = 3V AT 900MHz 2.0 2 1.6 1 1.2 0 –1 0.8 –1 –2 0.4 1 0 VOUT (V) TA = –40°C TA = 85°C –3 –60 –50 –40 –30 –20 –10 RF INPUT POWER (dBm) 0 –60 0 TA = 25°C TA = 85°C TA = –40°C –40 –30 –20 –10 RF INPUT POWER (dBm) –50 LINEARITY ERROR (dB) VOUT VARIATION (dB) 2 2.4 VCC = 3V AT 50MHz NORMALIZED AT 25°C –2 0 –3 5534 G05 5534 G04 3 Output Voltage vs RF Input Power 2.4 VCC = 3V AT 900MHz NORMALIZED AT 25°C 3 VCC = 3V AT 1.9GHz 2.0 2 1.6 1 1.2 0 –1 0.8 –1 –2 0.4 1 0 VOUT (V) TA = –40°C TA = 85°C –3 –60 –50 –40 –30 –20 –10 RF INPUT POWER (dBm) 0 –60 0 TA = 25°C TA = 85°C TA = –40°C –50 –40 –30 –20 –10 RF INPUT POWER (dBm) LINEARITY ERROR (dB) VOUT VARIATION (dB) 2 VOUT Variation vs RF Input Power –2 0 –3 5534 G07 5534 G06 3 Output Voltage vs RF Input Power 2.4 VCC = 3V AT 1.9GHz NORMALIZED AT 25°C 2.0 3 VCC = 3V AT 2.5GHz 2 1 1.2 0 –1 0.8 –1 –2 0.4 TA = 85°C 0 TA = –40°C –3 –60 –50 VOUT (V) 1.6 1 –40 –30 –20 –10 RF INPUT POWER (dBm) 0 0 –60 TA = 25°C TA = 85°C TA = –40°C –50 –40 –30 –20 –10 RF INPUT POWER (dBm) LINEARITY ERROR (dB) VOUT VARIATION (dB) 2 VOUT Variation vs RF Input Power –2 0 –3 5534 G09 5534 G08 5534fc 4 LT5534 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C TA = 85°C PERCENTAGE DISTRIBUTION (%) TA = –40°C –1 Output Voltage Distribution vs Temperature 2.4 0 50MHz VCC = 3V, 5V 1.6 1.9GHz VCC = 3V, 5V 1.2 0.8 –2 0.4 –40 –30 –20 –10 RF INPUT POWER (dBm) 0 0 –60 –50 –30 –10 –40 –20 RF INPUT POWER (dBm) 0 5534 G11 35 RF P = –48dBm AT 1.9GHz IN VCC = 3V 30 20 15 10 5 0 0.54 0.56 0.58 0.6 0.62 0.64 0.66 0.68 0.7 VOUT (V) 5534 G12 Output Voltage Distribution vs Temperature 40 35 RF PIN = –14dBm AT 1.9GHz VCC = 3V Supply Voltage vs Supply Current 10 TA = 25°C TA = –40°C TA = 85°C 9 30 25 20 15 10 TA = 85°C 8 TA = 25°C 7 TA = –40°C 6 5 5 0 TA = 25°C TA = –40°C TA = 85°C 25 5534 G10 SUPPLY CURRENT (mA) –50 PERCENTAGE DISTRIBUTION (%) –3 –60 Output Voltage vs RF Input Power at VCC = 3V and 5V 2.0 1 4 1.79 1.81 1.83 1.85 1.87 1.89 1.91 1.93 VOUT (V) 2.5 3 3.5 4 4.5 SUPPLY VOLTAGE (V) 5 5.5 5530 G14 5534 G13 Output Transient Response RF Input Return Loss vs Frequency 0 –5 1V/DIV RETURN LOSS (dB) VOUT VARIATION (dB) 2 2.8 VCC = 3V AT 2.5GHz NORMALIZED AT 25°C VOUT (V) 3 VOUT Variation vs RF Input Power (Test circuit shown in Figure 1) –10 VOUT –15 –20 RF INPUT PULSED RF 0dBm AT 100MHz –25 –30 0 1 1.5 2 2.5 0.5 RF INPUT FREQUENCY (GHz) 3 50ns/DIV 5534 G16 5534 G15 5534fc 5 LT5534 PIN FUNCTIONS EN (Pin 1): Enable. When the input voltage is higher than 0.9V, the circuit is completely turned on. When the input voltage is less than 0.6V, the circuit is turned off. VCC (Pin 4): Power Supply. This pin should be decoupled using 100pF and 0.1µF capacitors. RF (Pin 6): RF Input. This pin is internally biased to VCC – 0.18V. A coupling capacitor must be used to connect to the RF signal source. GND (Pins 2, 5): Ground. VOUT (Pin 3): RF Detector Output. BLOCK DIAGRAM 4 VCC DET 6 DET RF LIMITER RF DET DET RF LIMITER RF LIMITER DET + – RF LIMITER VOUT 3 VREF OFFSET COMP 2 GND BIAS 5 1 EN 5534 BD TEST CIRCUIT VOUT 6 RF LT5534 5 2 GND GND 1 EN R2 0Ω OPTIONAL 3 C5 OPTIONAL C1 1nF EN VOUT VCC R1 47Ω OPTIONAL 4 C3 100pF C2 0.1µF J1 RF VCC 5534 F01 REF DES VALUE C1 1nF C2 0.1µF C3 100pF C5 R1 47Ω R2 0Ω SIZE 0402 0603 0603 0603 0402 0603 PART NUMBER AVX 04025C102JAT2A TAIYO YUDEN TMK107BJ104KA AVX 06035C101KAT2A OPTIONAL OPTIONAL OPTIONAL Figure 1. Evaluation Circuit Schematic 5534fc 6 LT5534 TEST CIRCUIT Figure 2. Component Side Silkscreen of Evaluation Board Figure 3. Component Side Layout of Evaluation Board APPLICATIONS INFORMATION The LT5534 is a logarithmic-based detector, capable of measuring an RF signal over the frequency range from 50MHz to 3GHz. The 60dB linear dynamic range is achieved with very stable output over the full temperature range from –40°C to 85°C. The absolute variation over temperature is typically within ±1dB over a 47dB dynamic range at 1.9GHz. RF Input Port Table 1. RF Input Impedance FREQUENCY (MHz) INPUT IMPEDANCE (Ω) MAG S11 ANGLE (DEG) 50 1429-j429 0.938 –1.1 100 947-j710 0.934 –2.9 200 509-j609 0.922 –5.6 400 250-j440 0.908 –9.9 600 149-j344 0.900 –14.1 800 96.8-j278 0.896 –18.3 The RF port is internally biased at VCC-0.18V. The pin should be DC blocked when connected to ground or other matching components. A 47Ω resistor (R1) connected to ground will provide better than 10dB input return loss up to 2.5GHz. An additional 2nH inductance in series with R1 will provide improved input matching up to 3GHz. The impedance vs frequency of the RF input is detailed in Table 1. 1000 67.6-j229 0.893 –22.7 1200 49.7-j193 0.889 –27.3 1400 38.4-j165 0.883 –32.3 1600 30.8-j143 0.879 –37.3 1800 25.4-j125 0.873 –42.6 2000 21.4-j109 0.866 –48.0 2200 18.5-j96.2 0.862 –53.6 2400 16.6-j85.0 0.848 –59.6 The approximate linear RF input power range of the LT5534 is from –62dBm to –2dBm with a 50Ω source impedance. However, this range can be adjusted either upward or 2600 15.2-j75.7 0.834 –65.6 2800 13.7-j67.5 0.826 –71.8 3000 12.1-j60.1 0.822 –78.2 5534fc 7 LT5534 APPLICATIONS INFORMATION downward to tailor for a particular application need. By simply inserting an attenuator in front of the RF input, the power range is shifted higher by the amount of the attenuation. Moreover, due to the high RF input impedance of the LT5534, the detecting range can be moved downward for better detection sensitivity by using a narrow band L-C matching network. By this means, the sensitivity of the detector can be extended to as low as –75dBm. By changing the value of resistor R1, the sensitivity of the detector can be fine-tuned within the range from –75dBm to –62dBm. Though the range is adjustable, the overall linear dynamic range remains the same. When the output is terminated with a load capacitance CL, the slew rate is then limited to 200µA/(CL + 1.5pF). For example, the slew rate is reduced to 17.4V/µs when CL = 10pF. A capacitive load may result in output voltage overshoot, which can be minimized with a series compensation resistor R2, as shown in Figure 1. The suggested resistor values for various capacitive loads are listed in Table 2. Table 2. Resistor Value for Capacitive Output Output Interface The output interface of the LT5534 is shown in Figure 4. The output currents from the RF detectors are summed and converted into an output voltage, VOUT. The maximum charging current available to the output load is about 200µA. The internal compensation capacitor CC is used to guarantee stable operation for a large capacitive output load. The slew rate is 133V/µs, and the small-signal output bandwidth is approximately 30MHz when the output is resistively terminated or open. The fastest output transient response is achieved when a large signal is applied to the RF input port. See the Output Transient Response plot in the Typical Performance Characteristics section. C5 (pF) R2 (kΩ) 1.5 5 5 4 10 2.5 20 2 The optional RC network at the output (R2 and C5 on the demo board) can also provide further output filtering, if needed. The output bandwidth is primarily dictated by the RC constant of this lowpass filter when its corner frequency is less than 30MHz. When a large signal (e.g., –2dBm) is present at the RF input port, the output voltage swing can be as high as 2.4V. To assure proper operation of the chip, the minimum resistive load at the output termination should be greater than 18kΩ. VCC + 200µA + CC VOUT – 5534 F04 OUTPUT CURRENTS FROM RF DETECTORS Figure 4. Simplified Circuit Schematic of the Output Interface 5534fc 8 LT5534 REVISION HISTORY (Revision history begins at Rev B) REV DATE DESCRIPTION B 8/10 Revised Output DC Voltage minimum and maximum values in Electrical Characteristics section 3 Updated package drawing in Package Description section 10 Corrected part numbers in Order Information 2 C 12/10 PAGE NUMBER 5534fc 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. 9 LT5534 PACKAGE DESCRIPTION SC6 Package 6-Lead Plastic SC70 (Reference LTC DWG # 05-08-1638 Rev B) 0.47 MAX 0.65 REF 1.80 – 2.20 (NOTE 4) 1.00 REF INDEX AREA (NOTE 6) 1.80 – 2.40 1.15 – 1.35 (NOTE 4) 2.8 BSC 1.8 REF PIN 1 RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.10 – 0.40 0.15 – 0.30 6 PLCS (NOTE 3) 0.65 BSC 0.80 – 1.00 0.00 – 0.10 REF 1.00 MAX GAUGE PLANE 0.15 BSC 0.26 – 0.46 0.10 – 0.18 (NOTE 3) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm SC6 SC70 1205 REV B 6. DETAILS OF THE PIN 1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE INDEX AREA 7. EIAJ PACKAGE REFERENCE IS EIAJ SC-70 8. JEDEC PACKAGE REFERENCE IS MO-203 VARIATION AB RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT5504 800MHz to 2.7GHz RF Measuring Receiver 80dB Dynamic Range, Temperature Compensated, 2.7V to 5.25V Supply LT5506 500MHz Quadrature IF Demodulator with VGA 1.8V to 5.25V Supply, 40MHz to 500MHz IF, –4dB to 57dB Linear Power Gain, 8.8MHz Baseband Bandwidth LT5511 High Linearity Upconverting Mixer RF Output to 3GHz, 17dBm IIP3, Integrated LO Buffer LT5512 DC-3GHz High Signal Level Downconverting Mixer DC to 3GHz, 21dBm IIP3, Integrated LO Buffer LT5515 1.5GHz to 2.5GHz Direct Conversion Quadrature Demodulator 20dBm IIP3, Integrated LO Quadrature Generator LT5516 0.8GHz to 1.5GHz Direct Conversion Quadrature Demodulator 21.5dBm IIP3, Integrated LO Quadrature Generator LT5517 40MHz to 900MHz Direct Conversion Quadrature Demodulator 21dBm IIP3, Integrated LO Quadrature Generator LT5519 0.7GHz to 1.4GHz High Linearity Upconverting Mixer 17.1dBm IIP3, 50Ω Single-Ended RF and LO Ports LT5520 1.3GHz to 2.3GHz High Linearity Upconverting Mixer 15.9dBm IIP3, 50Ω Single-Ended RF and LO Ports LT5522 600MHz to 2.7GHz High Linearity Downconverting Mixer 4.5V to 5.25V Supply, 25dBm IIP3 at 900MHz, NF = 12.5dB, 50Ω Single-Ended RF and LO Ports LTC®5532 300MHz to 7GHz Precision RF Power Detector Precision VOUT Offset Control, Adjustable Gain and Offset LT5546 500MHz Quadrature IF Demodulator with VGA and 17MHz Baseband Bandwidth 17MHz Baseband Bandwidth, 40MHz to 500MHz IF, 1.8V to 5.25V Supply, –7dB to 56dB Linear Power Gain 5534fc 10 Linear Technology Corporation LT 1210 REV C • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2004