LTC5507 100kHz to 1GHz RF Power Detector U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Temperature Compensated Internal Schottky Diode RF Detector Wide Input Power Range: –34dBm to 14dBm Ultra Wide Input Frequency Range: 100kHz to 1000MHz Buffered Output Wide VCC Range of 2.7V to 6V Low Operating Current: 550µA Low Shutdown Current: <2µA Low Profile (1mm) ThinSOTTM Package U APPLICATIO S ■ ■ ■ The RF input voltage is peak detected using an on-chip Schottky diode and external capacitor. The detected voltage is buffered and supplied to the VOUT pin. A power saving shutdown mode reduces supply current to less than 2µA. , LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation Wireless Transceivers Wireless and Cable Infrastructure RF Power Alarm Envelope Detector U ■ The LTC®5507 is an RF power detector for applications operating from 100kHz to 1000MHz. The input frequency range is determined by an external capacitor. A temperature-compensated Schottky diode peak detector and buffer amplifier are combined in a small 6-pin ThinSOT package. TYPICAL APPLICATIO Typical Detector Characteristics at 100kHz, 100MHz and 1000MHz 4 VBAT 2.7V TO 6V C2 5 C1 RF INPUT 6 LTC5507 VCC VOUT PCAP GND RFIN SHDN 3 2 1 VOUT DETECTED VOLTAGE TA = 25°C VCC = 2.7V TO 6V VOUT OUTPUT VOLTAGE (mV) 10000 1000 DISABLE ENABLE 5507 TA01 Figure 1. 100kHz to 1000MHz RF Power Detector 100kHz, 100MHz 1000MHz 100 –34 –26 –18 –10 –2 6 RF INPUT POWER (dBm) 14 5507 TA01b 5507f 1 LTC5507 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 to GND ......................... (VCC ± 1.8V) to 7V SHDN Voltage to GND ................ –0.3V to (VCC + 0.3V) PCAP Voltage to GND ........................(VCC – 1.8V) to 7V IVOUT ...................................................................... 5mA Operating Temperature Range (Note 2) .. – 40°C to 85°C Maximum Junction Temperature ......................... 125°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C TOP VIEW LTC5507ES6 SHDN 1 6 RFIN GND 2 5 PCAP VOUT 3 4 VCC S6 PART MARKING S6 PACKAGE 6-LEAD PLASTIC SOT-23 TJMAX = 125°C, θJA = 250°C/W LTZX 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 = 25°C. VCC = 3.6V, RF Input Signal is Off, unless otherwise noted. PARAMETER CONDITIONS MIN VCC Operating Voltage ● IVCC Shutdown Current SHDN = 0V ● IVCC Operating Current SHDN = VCC, IVOUT = 0mA ● VOUT VOL (No RF Input) RLOAD = 2k, SHDN = VCC, Enabled SHDN = 0V, Disabled VOUT Output Current VOUT = 1.75V, VCC = 2.7V to 6V, ∆VOUT = 10mV ● VOUT Enable Time SHDN = VCC, CLOAD = 33pF, RLOAD = 2k ● VOUT Load Capacitance (Note 4) ● VOUT Noise VCC = 3V, Noise BW = 1.5MHz, 50Ω RF Input Termination 2.7 MAX VCC = 2.7V to 6V ● SHDN Voltage, Chip Enabled VCC = 2.7V to 6V ● SHDN Input Current SHDN = 3.6V ● UNITS 6 V 2 µA 0.55 0.85 mA 130 250 1 370 mV mV 1 2 7 mA 20 µs 33 pF 2 SHDN Voltage, Chip Disabled RFIN Input Frequency Range TYP mVP-P 0.35 1.4 V V 24 40 µA 0.1– 1000 MHz Max RFIN Input Power (Note 3) 14 dBm RFIN AC Input Resistance F = 10MHz, RF Input = –10dBm F = 1000MHz, RF Input = –10dBm 130 95 Ω Ω 1.7 pF RFIN Input Shunt Capacitance Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Specifications over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: RF performance is tested at: 80MHz, –4dBm Note 4: Guaranteed by design. 5507f 2 LTC5507 U W TYPICAL PERFOR A CE CHARACTERISTICS LTC5507 Typical Detector Characteristics, 100kHz, VCC = 2.7V TO 6V 10000 LTC5507 Typical Detector Characteristics, 100MHz VCC = 2.7V TO 6V 10000 C1 = 1000pF C2 = 1000pF VOUT OUTPUT VOLTAGE (mV) VOUT OUTPUT VOLTAGE (mV) C1 = 0.47µF C2 = 0.47µF 1000 1000 TA = –40°C TA = 85°C TA = –40°C TA = 85°C TA = 25°C 100 –34 –28 –22 –16 –10 –4 2 RF INPUT POWER (dBm) 8 TA = 25°C 100 –34 –28 –22 –16 –10 –4 2 RF INPUT POWER (dBm) 14 5507 G01 Positive VOUT Slew Rate vs C2 Capacitance 1000 10.0 POSITIVE VOUT SLEW RATE (V/µs) C1 = 33pF C2 = 33pF VOUT OUTPUT VOLTAGE (mV) 14 5507 G02 LTC5507 Typical Detector Characteristics, 1000MHz VCC = 2.7V TO 6V 10000 8 1.0 0.10 TA = –40°C TA = 85°C TA = 25°C 100 –34 –28 –22 –16 –10 –4 2 RF INPUT POWER (dBm) 0.01 8 33 14 330 3300 33000 C2 CAPACITANCE (pF) 5507 G03 5507 G04 Negative VOUT Slew Rate vs C2 Capacitance VOUT BW vs C2 Capacitance 10000 10.000 1.000 1000 VOUT BW (kHz) NEGATIVE VOUT SLEW RATE (V/µs) 330000 0.100 0.010 100 10 0.001 0 33 330 3300 33000 C2 CAPACITANCE (pF) 330000 5507 G05 1 33 330 3300 33000 C2 CAPACITANCE (pF) 330000 5507 G06 5507f 3 LTC5507 U U U PI FU CTIO S SHDN (Pin 1): Shutdown Input. A logic low or no-connect 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 the enable driver is in a tri-state condition. VCC (Pin 4): Power Supply Voltage, 2.7V to 6V. VCC should be bypassed with 0.1µF and 100pF ceramic capacitors. GND (Pin 2): System Ground. RFIN (Pin 6): RF Input Voltage. Referenced to VCC. A coupling capacitor must be used to connect to the RF signal source. This pin has an internal 250Ω termination and an internal Schottky diode detector. PCAP (Pin 5): Peak Detector Hold Capacitor. Capacitor value is dependent on RF frequency. Capacitor must be connected between PCAP and VCC. VOUT (Pin 3): Buffered and Level Shifted Detector Output Voltage. W BLOCK DIAGRA VCC 4 GAIN COMPRESSION + BUFFER C1 250Ω RFSOURCE VOUT – 6 SHDN RFIN 30k 30k C2 VCC 3 100Ω + 5 PCAP RF DET – 60µA 60µA 150k BIAS GND 2 1 C1 = C2 C2 (µF) ≥ 1 , f = LOWEST RF INPUT FREQUENCY (MHz) 30f 5507 BD SHDN Figure 2. 5507f 4 LTC5507 U W U U APPLICATIO S I FOR ATIO Operation Applications The LTC5507 integrates several functions to provide RF power detection over frequencies up to 1000MHz. These functions include an internally compensated buffer amplifier, an RF Schottky diode peak detector and level shift amplifier to convert the RF 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. The LTC5507 can be used as a self-standing signal strength measuring receiver for a wide range of input signals from –34dBm to 14dBm for frequencies up to 1000MHz. Buffer Amplifier 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 VCC – 0.1V. RF Detector The internal RF Schottky diode peak detector and level shift amplifier converts the RF input signal to a low frequency signal. The frequency range of the RF pin is typically up to 1000MHz. The detector demonstrates excellent operation over a wide range of input power. The Schottky detector is biased at about 70µA. The hold capacitor is external. The LTC5507 can be used as a demodulator for AM and ASK modulated signals with data rates up to 1.5MHz. 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. C1, C2 Capacitor Selection (Refer to Figure 3) C1 couples the RF input signal to the detector input RFIN which is referenced to VCC. C2 is the peak detector capacitor connected between PCAP and VCC. The value of C2 will affect the slew rate and bandwidth. Typically C1 can equal C2. Ceramic capacitors are recommended for C1 and C2. The values for C1 and C2 are dependent on the operating RF frequency. The capacitive reactance should be less than 5Ω to minimize ripple on C2. C2(µF) ≥ 1/(30 • f) where f is the lowest RF input frequency (MHz) C1 = C2 Gain Compression The gain compression circuit changes the feedback ratio as the RF peak-detected input voltage increases above 60mV. Below 60mV, the DC voltage gain from the peak detector to the buffer output is 4. Above 140mV, the DC voltage gain is reduced to 0.75. The compression expands the low power detector range due to higher gain. In general, select C1 and C2 large enough to pass the lowest expected RF signal frequency, as described by the above formulas. But optimize C1 and C2, subject to this constraint, to improve output slew rate and bandwidth, and to enable good AC performance for the highest expected RF signal frequency. Modes of Operation MODE SHDN OPERATION Shutdown Low Disabled Enable High Power Detect 5507f 5 LTC5507 U U W U APPLICATIO S I FOR ATIO SHDN E4 R3* 22k R4* 1 JP1 2 VOUT GND E2 E3 J1 RFIN VCC SHDN R2* 68Ω C5* 3 LTC5507 SHDN RFIN GND PCAP VOUT VCC C1 6 5 4 C2 C4* 0.1µF VCC E1 VCC C3* 100pF 5507 F03 * OPTIONAL COMPONENTS R2 AND C5 FORM AN OPTIONAL OUTPUT LOWPASS FILTER. R3 IS USED FOR DEMO PURPOSES ONLY, AND IS NOT USED IN ACTUAL PRODUCT IMPLEMENTATION. R4 CAN BE USED FOR INPUT POWER LIMITING OR BROADBAND IMPEDANCE MATCHING. C3 AND C4 ARE OPTIONAL POWER SUPPLY FILTERS. Figure 3. Evaluation Demo Board Schematic 5507f 6 LTC5507 U PACKAGE DESCRIPTIO S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636) 0.62 MAX 2.90 BSC (NOTE 4) 0.95 REF 1.22 REF 3.85 MAX 2.62 REF 1.4 MIN 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE ID RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 6 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) 1.90 BSC S6 TSOT-23 0302 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. JEDEC PACKAGE REFERENCE IS MO-193 5507f 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 LTC5507 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS RF Power Controllers LTC1757A RF Power Controller Multiband GSM/DCS/GPRS Mobile Phones LTC1758 RF Power Controller Multiband GSM/DCS/GPRS Mobile Phones LTC1957 RF Power Controller Multiband GSM/DCS/GPRS Mobile Phones LTC4400 ThinSOT RF PA Controller Multiband GSM/DCS/GPRS Phones, 45dB Dynamic Range, 450kHz Loop BW LTC4401 ThinSOT RF PA Controller Multiband GSM/DCS/GPRS Phones, 45dB Dynamic Range, 250kHz Loop BW LTC4403 Multiband RF Power Controllers for EDGE/TDMA Supports EDGE/TDMA Applications LT5504 800MHz to 2.7GHz RF Measuring Receivers 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 LTC5508 300MHz to 7GHz RF Power Detector >40dB Dynamic Range, SC-70 Package Other Related Parts LT5500 1.8GHz to 2.7GHz, Receiver Front End Dual LNA gain Setting +13.5dB/–14dB at 2.5GHz, Double-Balanced Mixer, 1.8V to 5.25V Supply 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 LT5506 500MHz Quadrature IF Demodulator with VGA 1.8V to 5.25V Supply, 40MHz to 500MHz IF, –4dB to 57dB Linear Power Gain LT5511 High Signal Level Upconverting Mixer 10MHz to 3000MHz RF Output Range, Integrated LO Buffer, 17dBm IIP3 LT5512 High Signal Level Down Converting Mixer DC-3GHz, 20dBm IIP3, Integrated LO Buffer 5507f 8 Linear Technology Corporation LT/TP 0103 2K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2001