LTC5505-1/LTC5505-2 RF Power Detector with Buffered Output and >40dB Dynamic Range U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ The LTC®5505-X is an RF power detector for RF applications operating in the 300MHz to 3.5GHz range. A temperature compensated Schottky diode peak detector and buffer amplifier are combined in a small 5-pin ThinSOT package. The supply voltage range is optimized for operation from a single lithium-ion cell or 3xNiMH. Internal Schottky Diode RF Detector with Two Input Power Ranges: LTC5505-1, –28dBm to 18dBm LTC5505-2, –32dBm to 12dBm Wide Input Frequency Range: 300MHz to 3GHz (LTC5505-1); 300MHz to 3.5GHz (LTC5505-2) Temperature Compensated Buffered Detector Output Wide VCC Range of 2.7V to 6V Low Operating Current: 0.5mA Low Shutdown Current: <2µA Low Profile (1mm) ThinSOTTM Package 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 2µA. The LTC5505-1 operates with input power levels from –28dBm to 18dBm. The LTC5505-2 operates with input power levels from –32dBm to 12dBm. U APPLICATIO S ■ ■ ■ ■ ■ Multimode Mobile Phone Products PCS Devices Wireless Data Modems Wireless and Cable Infrastructure RF Power Alarm Envelope Detector U ■ , LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation TYPICAL APPLICATIO Dual Band Mobile Phone Tx Power Control R1 100Ω RF 1 2 DISABLE ENABLE 3 LTC5505-X VCC 5 RFIN GND SHDN VOUT 4 MOBILE PHONE DSP C1 0.3pF Tx PA MODULE C2 0.1µF Li-Ion CELL BAND DIPLEXER PCS BAND VPC 5505 TA01 BSE 5505f 1 LTC5505-1/LTC5505-2 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 RF Voltage LTC5505-1 ................................... (VCC – 2.6V) to 7V LTC5505-2 ................................... (VCC – 1.4V) to 7V SHDN Voltage to GND ................ –0.3V to (VCC + 0.3V) 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 RFIN 1 LTC5505-1ES5 LTC5505-2ES5 5 VCC GND 2 SHDN 3 4 VOUT S5 PART MARKING S5 PACKAGE 5-LEAD PLASTIC SOT-23 TJMAX = 125°C, θJA = 250°C/W LTXV LTRW 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, SHDN = VCC = HI, SHDN = 0V = LO, RF Input Signal is Off, unless otherwise noted. PARAMETER CONDITIONS VCC Operating Voltage MIN ● 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 MAX UNITS 6 V 2 µA 0.5 0.75 mA 170 260 1 350 mV mV 1 2 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 7) VOUT Slew Rate VRFIN = 2V Step, CLOAD = 33pF, RLOAD = 2k (Note 3) 10 V/µs VOUT Noise VCC = 3V, Noise BW = 1.5MHz, 50Ω RF Input Termination 1.4 mVP-P 8 mA 20 4 SHDN Voltage, Chip Disabled VCC = 2.7V to 6V ● SHDN Voltage, Chip Enabled VCC = 2.7V to 6V ● SHDN Input Current SHDN = 3.6V ● MHz 33 ● µs 0.35 1.4 pF V V 24 40 µA 5505f 2 LTC5505-1/LTC5505-2 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VCC = 3.6V, SHDN = VCC = HI, SHDN = 0V = LO, RF Input Signal is Off, unless otherwise noted. PARAMETER CONDITIONS MIN RFIN Input Frequency Range (LTC5505-1) (LTC5505-2) TYP MAX UNITS 300 to 3000 300 to 3500 MHz MHz RFIN Input Power Range (LTC5505-1) RF Frequency = 900MHz (Note 5, 6, 7) VCC = 2.7V to 6V RF Frequency = 1800MHz (Note 5, 6, 7)VCC = 2.7V to 6V RF Frequency = 2400MHz (Note 5, 7)VCC = 2.7V to 6V RF Frequency = 2700MHz (Note 5, 7)VCC = 2.7V to 6V –28 to 18 –26 to 18 –24 to 16 –22 to 16 dBm dBm dBm dBm RFIN Input Power Range (LTC5505-2) RF Frequency = 900MHz (Note 5) RF Frequency = 1800MHz (Note 5) RF Frequency = 2400MHz (Note 5) RF Frequency = 2700MHz (Note 5) –32 to 12 –32 to 12 –32 to 12 –30 to 12 dBm dBm dBm dBm RFIN AC Input Resistance (LTC5505-1) F = 850MHz F = 1850MHz RFIN Input Shunt Capacitance (LTC5505-1) RFIN AC Input Resistance (LTC5505-2) F = 850MHz F = 1850MHz RFIN Input Shunt Capacitance (LTC5505-2) 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: 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. 165 20 Ω Ω 2 pF 165 59 Ω Ω 1.3 pF Note 5: RF performance is tested at: 1800MHz, 14dBm, –14dBm (LTC5505-1) 1800MHz, 12dBm, –14dBm (LTC5505-2) Note 6: For input RF power levels >16dBm, VCC minimum is 3V and an RF input series resistor of 20Ω is required to limit the input current. Note 7: Guaranteed by design. 5505f 3 LTC5505-1/LTC5505-2 U W TYPICAL PERFOR A CE CHARACTERISTICS 10000 VCC = 2.7V TO 6V 0Ω SERIES TERMINATION –40°C 25°C 85°C VOUT OUTPUT VOLTAGE (mV) VOUT OUTPUT VOLTAGE (mV) 10000 LTC5505-1 Typical Detector Characteristics, 2.45GHz LTC5505-1 Typical Detector Characteristics, 1.85GHz 10000 VCC = 2.7V TO 6V 0Ω SERIES TERMINATION –40°C 25°C 85°C VOUT OUTPUT VOLTAGE (mV) LTC5505-1 Typical Detector Characteristics, 0.85GHz 1000 1000 100 0 6 –30 –24 –18 –12 –6 RF INPUT POWER (dBm) 12 1000 100 –30 –24 –18 –12 –6 0 6 RF INPUT POWER (dBm) LTC5505-2 Typical Detector Characteristics, 0.85GHz 100 0 6 –30 –24 –18 –12 –6 RF INPUT POWER (dBm) 12 5505 G03 LTC5505-2 Typical Detector Characteristics, 1.85GHz 10000 VCC = 2.7V TO 6V 0Ω SERIES TERMINATION –40°C 25°C 85°C VOUT OUTPUT VOLTAGE (mV) VCC = 2.7V TO 6V 0Ω SERIES TERMINATION –40°C 25°C 85°C VOUT OUTPUT VOLTAGE (mV) 12 5505 G02 5505 G01 10000 VCC = 2.7V TO 6V 0Ω SERIES TERMINATION –40°C 25°C 85°C 1000 1000 100 –32 –26 –20 –14 –8 –2 4 RF INPUT POWER (dBm) 100 –32 10 –26 –20 –14 –8 –2 4 RF INPUT POWER (dBm) 5505 G04 5505 G05 LTC5505-2 Typical Detector Characteristics, 2.45GHz LTC5505-2 Typical Detector Characteristics, 3.5GHz 10000 VCC = 2.7V TO 6V 0Ω SERIES TERMINATION –40°C 25°C 85°C VOUT OUTPUT VOLTAGE (mV) VOUT OUTPUT VOLTAGE (mV) 10000 VCC = 2.7V TO 6V 0Ω SERIES TERMINATION –40°C 25°C 85°C 1000 1000 100 –32 10 –26 –20 –14 –8 –2 4 RF INPUT POWER (dBm) 10 5505 G06 100 –32 –26 –20 –14 –8 –2 4 RF INPUT POWER (dBm) 10 5505 G07 5505f 4 LTC5505-1/LTC5505-2 U U U PI FU CTIO S RFIN (Pin 1): RF Input Voltage. Referenced to VCC. An external coupling capacitor to the RF source is required. The frequency range is 300MHz to 3GHz. This pin has an internal 250Ω termination, an internal Schottky diode detector and peak detector capacitor. (See Note 6 in the Electrical Characteristics.) GND (Pin 2): System Ground. SHDN (Pin 3): 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 the drivers are in a tri-state condition. VOUT (Pin 4): Buffered and Level Shifted Detector Output Voltage. VCC (Pin 5): Power Supply Voltage, 2.7V to 6V. VCC should be bypassed appropriately with ceramic capacitors. W BLOCK DIAGRA VCC 5 GAIN COMPRESSION + BUFFER 4 VOUT – SHDN 30k 250Ω RFIN 1 30k 100Ω 100Ω + 28pF RF DET 130mV – 60µA 22k 60µA BIAS 150k GND 2 3 5505 BD SHDN 5505f 5 LTC5505-1/LTC5505-2 U U W U APPLICATIO S I FOR ATIO Operation The LTC5505-X RF detector integrates several functions to provide RF power detection over frequencies ranging from 300MHz to 3.5GHz. These functions include an internally compensated buffer amplifier, an RF Schottky diode peak detector and level shift amplifier to convert the RF feedback 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 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 60µA 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 100mV. Below 100mV, the voltage gain from the peak detector to the buffer output is 1.5. Above 200mV, the voltage gain is reduced to 0.7. 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 LTC5505-1 and LTC5505-2 can be used as selfstanding signal strength measuring receivers for a wide range of input signals from –32dBm to 18dBm for frequencies from 300MHz to 3.5GHz. The LTC5505-1 and LTC5505-2 can be used as demodulators 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 (or audio) output and DC-coupled, RSSI output for signal strength measurements and AGC. The LTC5505-1 and LTC5505-2 can be used for dual band mobile phone transmitter power control (refer to Typical Application schematic on first page). The circuit uses a capacitive tap at the Tx PA outputs. For example, a 0.3pF capacitor (C1) followed by a 100Ω resistor (R1) forms a coupling circuit with about a 20dB loss at the cellular band and 18dB loss at the PCS band, referenced to the LTC5505-2 IC RF input pin. For improved coupling accuracy, the C1 capacitor should be a high tolerance component (±0.05pF.) Example of LTC5505-X GSM/DCS Power Control Timing Diagram 20µs 2µs 28µs 543µs 28µs SHDN VOUT RF INPUT POWER 5505 TD t1 t2 t3 t4 t 1: PART COMES OUT OF SHUTDOWN 20µs MAXIMUM PRIOR TO BURST. t 2: CIRCUITS POWER UP AND SETTLE. t 3: BASEBAND CONTROLLER STARTS RF POWER RAMP UP AT 22µs AFTER SHDN IS ASSERTED HIGH. t5 t6 t 4: BASEBAND CONTROLLER COMPLETES RAMP UP. t 5: BASEBAND CONTROLLER STARTS RF POWER RAMP DOWN AT END OF BURST. t 6: LTC5505-X RETURNS TO SHUTDOWN MODE BETWEEN BURSTS 5505f 6 LTC5505-1/LTC5505-2 U TYPICAL APPLICATIO Dual Band Mobile Phone Tx Power Control with Directional Coupler 0Ω TO 20Ω 33pF 1 2 3 DISABLE ENABLE LTC5505-X VCC 5 RFIN 0.1µF GND SHDN VOUT 4 900MHz INPUT 1.8GHz INPUT MOBILE PHONE DSP Li-Ion BSEL Tx PA MODULE VPC DIRECTIONAL COUPLER DIPLEXER 900MHz OUTPUT 1.8GHz OUTPUT 50Ω 5505 TA02 U PACKAGE DESCRIPTIO S5 Package 5-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1635) 2.90 BSC (NOTE 4) 0.754 0.854 ± 0.127 3.254 2.80 BCS 1.50 – 1.75 (NOTE 4) 0.95 BSC 1.9 BSC PIN ONE RECOMMENDED SOLDER PAD LAYOUT 0.30 – 0.45 TYP 5 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.35 – 0.50 REF 0.09 – 0.20 (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 6. JEDEC PACKAGE REFERENCE IS MO-193 1.90 BSC S5 TSOT-23 0801 5505f 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 LTC5505-1/LTC5505-2 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1618 Constant Current/Constant Voltage, 1.4MHz, High Efficiency Boost Regulator Up to 16 White LEDs, VIN = 1.6V to 18V, VOUT Max = 34V, IQ = 1.8mA, ISD = <1µA, MS10 LTC1733 Standalone Li-Ion Linear Battery Charger Monolithic Charger, Thermal Rejection Prevents Overheating, Small Design, Up to 1.5A Charge Current LTC1734/ LTC1734L Li-Ion Linear Battery Charger in ThinSOT 50mA to 700mA Charge Current, Only Three Components for Complete Solution LTC1878 600mA IOUT, 550kHz, Synchronous Step-Down DC/DC Converter 95% Efficiency, VIN = 2.7V to 6V, VOUT Min = 0.8V, IQ = 10µA, ISD = <1µA, MS8 LT1932 Constant Current, 1.2MHz, High Efficiency White LED Boost Regulator Up to 8 White LEDs, VIN = 1V to 10V, VOUT Max = 34V, IQ = 1.2mA, ISD = <1µA, ThinSOT LT1937 Constant Current, 1.2MHz, High Efficiency White LED Boost Regulator Up to 4 White LEDs, VIN = 2.5V to 10V, VOUT Max = 34V, IQ = 1.9mA, ISD = <1µA, ThinSOT, SC70 LTC3200 Low Noise, 2MHz, Regulated Charge Pump White LED Driver Up to 6 White LEDs, VIN = 2.7V to 4.5V, IQ = 8mA, ISD = <1µA, MS10 LTC3200-5 Low Noise, 2MHz, Regulated Charge Pump White LED Driver Up to 6 White LEDs, VIN = 2.7V to 4.5V, IQ = 6.5mA, ISD = <1µA, ThinSOT LTC3201 Low Noise, 1.7MHz, Regulated Charge Pump White LED Driver Up to 6 White LEDs, VIN = 2.7V to 4.5V, IQ = 6.5mA, ISD = <1µA, MS10 LTC3202 Low Noise, 1.5MHz, Regulated Charge Pump White LED Driver Up to 8 White LEDs, VIN = 2.7V to 4.5V, IQ = 5mA, ISD = <1µA, MS10 LTC3404 600mA IOUT, 1.4MHz, Synchronous Step-Down DC/DC Converter 95% Efficiency, VIN = 2.7V to 6V, VOUT Min = 0.8V, IQ = 10µA, ISD = <1µA, MS8 LTC3405/ LTC3405A 300mA IOUT, 1.5MHz, Synchronous Step-Down DC/DC Converter 95% Efficiency, VIN = 2.7V to 6V, VOUT Min = 0.8V, IQ = 20µA, ISD = <1µA, ThinSOT LTC3406/ LTC3406B 600mA IOUT, 1.5MHz, Synchronous Step-Down DC/DC Converter 95% Efficiency, VIN = 2.5V to 5.5V, VOUT Min = 0.6V, IQ = 20µA, ISD = <1µA, ThinSOT LTC3412 2.5A IOUT, 4MHz, Synchronous Step-Down DC/DC Converter 95% Efficiency, VIN = 2.5V to 5.5V, VOUT Min = 0.8V, IQ = 60µA, ISD = <1µA, TSSOP-16E LTC3411 1.25A IOUT, 4MHz, Synchronous Step-Down DC/DC Converter 95% Efficiency, VIN = 2.5V to 5.5V, VOUT Min = 0.8V, IQ = 60µA, ISD = <1µA, MS10 LTC3440 600mA IOUT, 2MHz, Synchronous Buck-Boost DC/DC Converter 95% Efficiency, VIN = 2.5V to 5.5V, VOUT Min = 2.5V, IQ = 25µA, ISD = <1µA, MS10 LTC4052 Li-Ion Battery Pulse Charger Minimum Heat Dissipation, Current Limit for Safety, Standalone Charger, Monolithic LTC4053 USB Compatible Li-Ion Charger Standalone, Monolithic, 100mA/500mA or Up to 2A from Wall Adapter LTC4412 TM Low Loss PowerPath Controller Replaces Power Supply ORing Diodes, High Efficiency PowerPath is a trademark of Linear Technology Corporation. 5505f 8 Linear Technology Corporation LT/TP 1102 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