LTC5508 300MHz to 7GHz RF Power Detector with Buffered Output in SC70 Package U DESCRIPTIO FEATURES Temperature Compensated Internal Schottky Diode RF Detector Wide Input Frequency Range: 300MHz to 7GHz Wide Input Power Range: -32dBm to 12dBm Buffered Detector Output Wide VCC Range of 2.7V to 6V Low Operating Current: 550A Low Shutdown Current: <2A SC70 Package U APPLICATIO S The RF input voltage is peak detected using an on-chip Schottky diode. The detected voltage is buffered and supplied to the VOUT pin. A power saving shutdown mode reduces supply current to less than 2A. The LTC5508 operates with input power levels from -32dBm to 12dBm. 802.11a, 802.11b, 802.11g, 802.15 Multimode Mobile Phone Products Optical Data Links Wireless Data Modems Wireless and Cable Infrastructure RF Power Alarm Envelope Detector , LTC and LT are registered trademarks of Linear Technology Corporation. U The LTC(R)5508 is an RF power detector for RF applications operating in the 300MHz to 7GHz range. A temperature compensated Schottky diode peak detector and buffer amplifier are combined in a small SC70 package. The supply voltage range is optimized for operation from a single lithium-ion cell or 3xNiMH. TYPICAL APPLICATIO Output Voltage vs RF Input Power 300MHz to 7GHz RF Power Detector RF INPUT 33pF 6 2 DISABLE ENABLE 1 LTC5508 VCC 4 RFIN 5 GND GND SHDN VOUT 3 VOUT VCC 100pF 0.1F VOUT OUTPUT VOLTAGE (mV) 10000 VCC = 3.6V TA = 25C 1000 2GHz 7GHz 1GHz 4GHz 6GHz 5508 TA01 100 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 5508 TA02 5508fa 1 LTC5508 U W W W ABSOLUTE AXI U RATI GS U W U PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART NUMBER VCC, VOUT to GND .................................... -0.3V to 6.5V RFIN Voltage ......................................(VCC 1.3V) to 7V SHDN Voltage to GND ................ -0.3V to (VCC + 0.3V) IVOUT ...................................................................... 5mA Operating Temperature Range (Note 2) .. - 40C to 85C Maximum Junction Temperature ......................... 125C Storage Temperature Range ................ - 65C to 150C Lead Temperature (Soldering, 10 sec)................. 300C TOP VIEW SHDN 1 6 RFIN GND 2 5 GND VOUT 3 4 VCC LTC5508ESC6 SC6 PART MARKING SC6 PACKAGE 6-LEAD PLASTIC SC70 TJMAX = 125C, JA = 256C/W LAAD Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VCC = 3.6V, SHDN = VCC = HI, SHDN = 0V = LO, RF Input Signal is Off, unless otherwise noted. PARAMETER CONDITIONS MIN VCC Operating Voltage IVCC Shutdown Current SHDN = LO IVCC Operating Current SHDN = HI, IVOUT = 0mA VOUT VOL (No RF Input) RLOAD = 2k, SHDN = HI, Enabled SHDN = LOW, Disabled TYP 2.7 150 MAX UNITS 6 V 2 A 0.55 0.85 mA 250 1 400 mV mV VOUT Output Current VOUT = 1.75V, VCC = 2.7V, VOUT = 10mV VOUT Enable Time SHDN = HI, CLOAD = 33pF, RLOAD = 2k VOUT Bandwidth CLOAD = 33pF, RLOAD = 2k (Note 4) VOUT Load Capacitance (Note 6) VOUT Slew Rate VRFIN = 2V Step, CLOAD = 33pF, RLOAD = 2k (Note 3) 5 V/s VOUT Noise VCC = 3V, Noise BW = 1.5MHz, 50 RF Input Termination 2 mVP-P SHDN Voltage, Chip Disabled VCC = 2.7V to 6V SHDN Voltage, Chip Enabled VCC = 2.7V to 6V SHDN Input Current SHDN = 3.6V 1 2 8 mA 20 2 RFIN Input Frequency Range MHz 33 s 0.35 1.4 pF V V 24 40 A 300 to 7000 MHz -32 to 12 dBm RFIN Input Power Range RF Frequency = 300MHz to 7GHz (Note 5, 6) VCC = 2.7V to 6V RFIN AC Input Resistance F = 1000MHz, Pin = -25dBm 150 RFIN Input Shunt Capacitance F = 1000MHz, Pin = -25dBm 0.6 pF Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Specifications over the -40C to 85C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: The rise time at VOUT is measured between 0.5V and 1.5V. Note 4: Bandwidth is calculated using the 10% to 90% rise time equation: BW = 0.35/rise time. Note 5: RF performance is tested at 1800MHz Note 6: Guaranteed by design. 5508fa 2 LTC5508 U W TYPICAL PERFOR A CE CHARACTERISTICS Typical Detector Characteristics, 300MHz 1000 10000 VCC = 3.6V 1000 TA = -40C TA = 85C TA = 25C 1000 TA = 85C TA = -40C TA = 25C 100 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 5508 G01 1000 TA = 85C TA = 25C TA = -40C TA = 85C TA = 25C 5508 G04 VCC = 3.6V 8 12 TA = -40C 100 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 5508 G06 Typical Detector Characteristics, 7000MHz 10000 VOUT OUTPUT VOLTAGE (mV) VCC = 3.6V TA = 85C TA = 25C 5508 G05 Typical Detector Characteristics, 6000MHz VOUT OUTPUT VOLTAGE (mV) Typical Detector Characteristics, 5000MHz 1000 100 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 8 12 5508 G03 10000 1000 10000 100 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 VCC = 3.6V VOUT OUTPUT VOLTAGE (mV) VOUT OUTPUT VOLTAGE (mV) 10000 100 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) TA = 25C Typical Detector Characteristics, 4000MHz VCC = 3.6V TA = -40C TA = 85C 5508 G02 Typical Detector Characteristics, 3000MHz 10000 TA = -40C VOUT OUTPUT VOLTAGE (mV) 100 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) VCC = 3.6V VOUT OUTPUT VOLTAGE (mV) 10000 VCC = 3.6V VOUT OUTPUT VOLTAGE (mV) VOUT OUTPUT VOLTAGE (mV) 10000 Typical Detector Characteristics, 2000MHz Typical Detector Characteristics, 1000MHz VCC = 3.6V 1000 1000 TA = -40C TA = 85C TA = 25C 100 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 5508 G07 TA = -40C TA = 85C TA = 25C 100 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 5508 G08 5508fa 3 LTC5508 U W TYPICAL PERFOR A CE CHARACTERISTICS VOUT Slope vs RF Input Power at 300MHz 1000 100 10 TA = -40C TA = 25C 1000 VCC = 3.6V VOUT SLOPE (mV/dB) VCC = 3.6V VOUT SLOPE (mV/dB) VOUT SLOPE (mV/dB) 1000 100 TA = -40C 10 TA = 25C TA = 85C 100 TA = -40C 10 TA = 25C TA = 85C 1 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 5508 G09 TA = -40C 10 TA = 25C 1000 VCC = 3.6V TA = -40C VCC = 3.6V 100 10 TA = -40C TA = 25C TA = 25C TA = 85C TA = 85C TA = 85C 1 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 1 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) VOUT Slope vs RF Input Power at 6000MHz 1000 VCC = 3.6V 100 10 TA = -40C TA = 25C 5508 G14 VCC = 3.6V 100 10 TA = -40C TA = 25C TA = 85C TA = 85C 1 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 VOUT Slope vs RF Input Power at 7000MHz VOUT SLOPE (mV/dB) 1000 1 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 5508 G13 5508 G12 VOUT SLOPE (mV/dB) VOUT Slope vs RF Input Power at 5000MHz 100 10 8 12 5508 G11 VOUT SLOPE (mV/dB) VOUT SLOPE (mV/dB) 100 8 12 VOUT Slope vs RF Input Power at 4000MHz 1000 VCC = 3.6V 1 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 5508 G10 VOUT Slope vs RF Input Power at 3000MHz VOUT SLOPE (mV/dB) VCC = 3.6V TA = 85C 1 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 1000 VOUT Slope vs RF Input Power at 2000MHz VOUT Slope vs RF Input Power at 1000MHz 8 12 5508 G15 1 -32 -28 -24 -20 -16 -12 -8 -4 0 4 RF INPUT POWER (dBm) 8 12 5508 G16 5508fa 4 LTC5508 U W TYPICAL PERFOR A CE CHARACTERISTICS RFIN Input Impedance (Pin = 0dBm, VCC = 3.6V, TA = 25C) FREQUENCY (GHz) RESISTANCE () REACTANCE () 1.000 129.136 -86.960 1.375 100.771 -92.142 1.750 73.844 -81.141 2.125 60.159 -68.796 2.500 50.135 -58.139 2.875 43.042 -48.927 3.250 37.570 -41.033 3.625 33.924 -33.346 4.000 30.923 -26.405 4.375 28.793 -20.012 4.750 26.992 -14.080 5.125 25.717 -8.323 5.500 24.920 -3.228 5.875 24.318 2.177 6.250 24.549 7.535 6.625 25.273 12.197 7.000 26.337 16.503 RFIN Input Impedance (Pin = -25dBm, VCC = 3.6V, TA = 25C) FREQUENCY (GHz) RESISTANCE () REACTANCE () 1.000 114.531 -63.267 1.375 95.061 -71.669 1.750 71.491 -64.607 2.125 59.563 -54.798 2.500 51.714 -46.844 2.875 44.940 -39.753 3.250 39.708 -32.738 3.625 36.151 -26.385 4.000 33.227 -20.478 4.375 31.108 -15.107 4.750 29.514 -9.941 5.125 27.899 -4.793 5.500 27.047 0.266 5.875 26.627 5.250 6.250 26.760 10.267 6.625 27.619 14.616 7.000 28.241 18.523 S11 Forward Reflection Impedance 1.000GHz-7.000GHz 5508 TA03 S11 Forward Reflection Impedance 1.000GHz-7.000GHz 5508 TA04 5508fa 5 LTC5508 U U U PI FU CTIO S SHDN (Pin 1): Shutdown Input. A logic low on the SHDN pin places the part in shutdown mode. A logic high enables the part. SHDN has an internal 150k pull down resistor to ensure that the part is in shutdown when no input is applied. GND (Pin 2, 5): Ground. VOUT (Pin 3): Detector Output. VCC (Pin 4): Power Supply Voltage, 2.7V to 6V. VCC should be bypassed appropriately with ceramic capacitors. RFIN (Pin 6): RF Input Voltage. Referenced to VCC. A coupling capacitor must be used to connect to the RF signal source. The frequency range is 300MHz to 7GHz. This pin has an internal 250 termination, an internal Schottky diode detector and a peak detector capacitor. W BLOCK DIAGRA RFSOURCE 12pF TO 200pF (DEPENDING ON APPLICATION) VCC 4 GAIN COMPRESSION + BUFFER 3 VOUT - SHDN 30k 250 RFIN 6 30k 20k 28pF 20k 60A 100 100 + RF DET 130mV - 40k 60A BIAS 150k GND 2 GND 5 1 5508 BD SHDN 5508fa 6 LTC5508 U U W U APPLICATIO S I FOR ATIO Operation The LTC5508 RF detector integrates several functions to provide RF power detection over frequencies ranging from 300MHz to 7GHz. These functions include an internally compensated buffer amplifier, an RF Schottky diode peak detector and level shift amplifier to convert the RF input signal to DC, a delay circuit to avoid voltage transients at VOUT when coming out of shutdown and a gain compression circuit to extend the detector dynamic range. Buffer Amplifier 60mV. Below 60mV, the voltage gain from the peak detector to the buffer output is 4. Above 120mV, the voltage gain is reduced to 0.85. The compression expands the low power detector range due to higher gain. Modes of Operation MODE SHDN OPERATION Shutdown Low Disabled Enable High Power Detect Applications The buffer amplifier has a gain of two and is capable of driving a 2mA load. The buffer amplifier typically has an output voltage range of 0.25V to 1.75V. RF Detector The internal RF Schottky diode peak detector and level shift amplifier converts the RF input signal to a low frequency signal. The detector demonstrates excellent efficiency and linearity over a wide range of input power. The Schottky detector is biased at about 60A and drives a peak detector capacitor of 28pF. Gain Compression The gain compression circuit changes the feedback ratio as the RF peak-detected input voltage increases above The LTC5508 can be used as a self-standing signal strength measuring receiver for a wide range of input signals from -32dBm to 12dBm for frequencies from 300MHz to 7GHz. The LTC5508 can be used as a demodulator for AM and ASK modulated signals with data rates up to 2MHz. Depending on specific application needs, the RSSI output can be split into two branches, providing AC-coupled data (or audio) output and DC-coupled, RSSI output for signal strength measurements and AGC. The LTC5508 can be used for RF power detection and control. Refer to Application Note 91, "Low Cost Coupling Methods for RF Power Detectors Replace Directional Couplers." Demo Board Schematic VCC R3 22k E4 SHDN C1 18pF ENABLE 1 2 DISABLE 3 JP1 VOUT E2 E3 GND R2 68 (OPT) C5 (OPT) GND GND VOUT VCC RFIN J1 SHDN RF LTC5508 R1 68 (OPT) VCC E1 VCC C2 0.1F C3 100pF E5 GND 5508 AI01 5508fa 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. 7 LTC5508 U PACKAGE DESCRIPTIO SC6 Package 6-Lead Plastic SC70 (Reference LTC DWG # 05-08-1638) 0.47 MAX 0.65 REF 1.80 - 2.20 (NOTE 4) 1.16 REF INDEX AREA (NOTE 6) 1.80 - 2.40 1.15 - 1.35 (NOTE 4) 0.96 MIN 3.26 MAX 2.1 REF PIN 1 RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.15 - 0.30 6 PLCS (NOTE 3) 0.65 BSC 0.10 - 0.40 0.80 - 1.00 0.00 - 0.10 REF 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 6. DETAILS OF THE PIN 1 INDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE INDEX AREA 7. EIAJ PACKAGE REFERENCE IS EIAJ SC-70 1.00 MAX 0.10 - 0.30 SC6 SC70 0802 0.10 - 0.18 (NOTE 3) RELATED PARTS PART NUMBER DESCRIPTION COMMENTS RF Power Controllers LTC1757A RF Power Controller Single/Dual Band GSM/DCS/GPRS Mobile Phones LTC1758 RF Power Controller Single/Dual Band GSM/DCS/GPRS Mobile Phones LTC1957 RF Power Controller Single/Dual Band GSM/DCS/GPRS Mobile Phones LTC4400 SOT-23 RF PA Controller Single/Dual Band GSM/DCS/GPRS Phones, 45dB Dynamic Range, 450kHz Loop BW LTC4401 SOT-23 RF PA Controller Single/Dual Band GSM/DCS/GPRS Phones, 45dB Dynamic Range, 250kHz Loop BW LT5500 1.8GHz to 2.7GHz RF Front End Dual LNA gain Setting +13.5dB/-14dB at 2.5GHz, Double-Balanced Mixer, 1.8V VSUPPLY 5.25V LT5502 400MHz Quadrature Demodulator with RSSI 1.8V to 5.25V Supply, 70MHz to 400MHz IF, 84dB Limiting Gain, 90dB RSSI Range LT5503 1.2GHz to 2.7GHz Direct IQ Modulator and Up Converting Mixer 1.8V to 5.25V Supply, Four-Step RF Power Control, 120MHz Modulation Bandwidth LT5504 800MHz to 2.7GHz RF Measuring Receiver 80dB Dynamic Range, Temperature Compensated, 2.7V to 5.5V Supply LTC5505 300MHz to 3.5GHz RF Power Detector >40dB Dynamic Range, Temperature Compensated, 2.7V to 6V Supply LT5506 500MHz Quadrature IF Demodulator with VGA 1.8V to 5.25V Supply, 40MHz to 500MHz IF, -4dB to 57dB Linear Power Gain LTC5507 100kHz to 1GHz RF Power Detector 48dB Dynamic Range, Temperature Compensated, 2.7V to 6V Supply LT5511 High Signal Level Up Converting Mixer RF Output to 3GHz, 17dBm IIP3, Integrated LO Buffer LT5512 High Signal Level Down Converting Mixer DC-3GHz, 20dBm IIP3, Integrated LO Buffer 5508fa 8 Linear Technology Corporation LT/TP REV A 0603 1K * PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear.com LINEAR TECHNOLOGY CORPORATION 2002