RF2371 Preliminary 4 3V LOW NOISE AMPLIFIER Typical Applications • GSM Handsets • IF or RF Buffer Amplifiers • CDMA Handsets • Driver Stage for Power Amplifiers • TDMA Handsets • Oscillator Loop Amplifiers Product Description 4 GENERAL PURPOSE AMPLIFIERS 0.365 TEXT* The RF2371 is a general purpose, low-cost, high performance low noise amplifier designed for operation from a 2.7V to 4V supply with low current consumption. The attenuation of the device is controlled when in power down mode, providing a known gain step. The RF2371 is available in a small industry-standard SOT23-8 surface mount package, enabling compact designs which conserve board space. The design features a highly accurate PTAT (Proportional To Absolute Temperature) biasing scheme using bandgap cells. 0.15 0.05 1.59 1.61 2.80 3.00 0.650 2.60 3.00 1.44 1.04 *When Pin 1 is in upper left, text reads downward (as shown). 0.127 3°MAX 0°MIN 0.35 0.55 Optimum Technology Matching® Applied Si BJT üSi Bi-CMOS GaAs HBT GaAs MESFET SiGe HBT Si CMOS Package Style: SOT23-8 Features • 700MHz to 2000MHz Operation • 2.7V to 3.6V Single Supply • +5dBm Input IP3 at 3.0mA 1 8 RF OUT • 12dB Gain at 1950MHz GND1 2 7 ISET • 1.8dB Noise Figure at 1950MHz 6 VCC • 17dB Gain Step 5 ENABLE RF IN GND2 3 Bias Circuits IPSET 4 Ordering Information RF2371 RF2371 PCBA Functional Block Diagram Rev A2 010205 3V Low Noise Amplifier Fully Assembled Evaluation Board RF Micro Devices, Inc. 7625 Thorndike Road Greensboro, NC 27409, USA Tel (336) 664 1233 Fax (336) 664 0454 http://www.rfmd.com 4-221 RF2371 Preliminary Absolute Maximum Ratings Parameter Supply Voltage Supply Current Operating Ambient Temperature Storage Temperature Parameter GENERAL PURPOSE AMPLIFIERS 4 Rating Unit 4.0 20 -40 to +85 -40 to +150 V mA °C °C Specification Min. Typ. Max. Caution! ESD sensitive device. RF Micro Devices believes the furnished information is correct and accurate at the time of this printing. However, RF Micro Devices reserves the right to make changes to its products without notice. RF Micro Devices does not assume responsibility for the use of the described product(s). Unit T=27° C, VCC =2.7V, VISELECT =0V, VENABLE =2.7V Overall Frequency Range 700 to 2000 MHz 12.5 1.6 +6 -14 5:1 dB dB dBm dBm dB dB dB dB dB dBm LNA Performance Gain Noise Figure Input IP3 Input P1dB Input VSWR Output VSWR Off Mode Gain Gain Noise Figure Input IP3 Condition Freq=1.95GHz 10.5 +4 1.5:1 -5.0 17 1.6 0 At 2.9mA (Noise match) VENABLE =0V Freq=836MHz Current Control Internal Current Setting “ON” External Current Setting “ON” Current into ISELECT CMOS Low CMOS High 1 V V µA Voltage on ISELECT Voltage on ISELECT VISELECT =2.7V 1 V V µA Voltage on ENABLE Voltage on ENABLE VENABLE =2.7V 5 1 V mA µA VCC =2.7V, Internal current setting VENABLE =0V Power Control Power “ON” Voltage Power “OFF” Voltage Current into ENABLE CMOS High CMOS Low Power Supply Operating Voltage Operating Current Leakage Current 4-222 2.7 to 3.6 2.9 Rev A2 010205 RF2371 Preliminary Function RF IN 2 GND1 3 4 GND2 IPSET 5 ENABLE 6 7 8 VCC ISET RF OUT Rev A2 010205 Description Interface Schematic RF input pin. This pin is not internally DC blocked and requires an external blocking capacitor. Ground connection for the LNA. Keep traces physically short and connect immediately to ground plane for best performance. Ground connection for the bias circuits. This pin selects the internal current setting when CMOS level “low”, and the external current setting when this pin is CMOS level “high”. Power down control. This is a CMOS input. When this pin is CMOS “high” the device is enabled. When the level is CMOS “low” the device is shut off and a controlled attenuator is turned on. Power supply for the bias circuits. 4 This pin sets the current for the device. RF output pin. Bias for the LNA is provided through this pin, hence it should be connected to VCC through an inductor. GENERAL PURPOSE AMPLIFIERS Pin 1 4-223 RF2371 Preliminary Application Information The RF2371 may be configured to use either the internal current setting or the external current setting. This choice is made by asserting IPSET, pin 4, to CMOS level “low” for the internal current setting or CMOS level “high” for the external current setting. Internal Current Setting When IPSET is set to CMOS “low”, the internal current settings are chosen. This current draw is typically 2.9mA. In this mode, the resistorR1 may be removed from the evaluation board schematic and ISET left floating. The condition for optimal IP3 is to use the internal current setting option and leave the ISET pin open (no connect). GENERAL PURPOSE AMPLIFIERS 4 External Current Setting The external current setting is configured by using the series resistor between ISET, pin7, and ground (refer to resistor R1 in evaluation board schematic). The value of the resistor may be changed to permit various operating currents up to a maximum allowable current of 20mA. The table below gives approximate minimum R1 values to allow the 20mA maximum current draw at various operating voltages. Note: When the internal current setting was selected, the part tested drew 4.4mA, which is higher than typical (2.9mA). Thus values of R1 given vary from part to part. VCC (V) Resistor R1 (Ω) Current Draw (mA) 2.7 2.4k 20.1 3.0 2.7k 20.1 3.3 3.0k 20.0 3.6 3.3k 19.8 4-224 Rev A2 010205 RF2371 Preliminary Application Schematic 1.95GHz VCC 3.3 nH 22 nF RF IN 1 10 nF 1.5 pF RF OUT 8 1 kΩ 2 7 3 6 VCC 4 Bias Circuits 4 ENABLE 5 GENERAL PURPOSE AMPLIFIERS IPSET Application Schematic 836MHz VCC 18 nH 22 nF RF IN 82 nH 1 8 2 7 3 6 1 pF RF OUT 1 kΩ VCC Bias Circuits IPSET Rev A2 010205 4 5 ENABLE 4-225 RF2371 Preliminary Evaluation Board Schematic (Download Bill of Materials from www.rfmd.com.) VCC L1 3.9 nH C1 22 nF J2 LNA INPUT L2 10 nH GENERAL PURPOSE AMPLIFIERS 4 1 8 2 7 3 6 C2 1.5 pF R1 1 kΩ J1 LNA OUTPU VCC Bias Circuits IPSET 4 ENABLE 5 2371400- IPSET VCC ENABLE ENVCC+ 2.6 V C3 1 nF C4 1 uF + C5 22 nF VCC+ 2.7 V- P1 1 VCC 2 ENABLE 3 IPSET GND 4 CON4 4-226 Rev A2 010205 RF2371 Preliminary Evaluation Board Layout Board Size 0.833” x 1.009” Board Thickness 0.031”, Board Material FR-4 GENERAL PURPOSE AMPLIFIERS 4 Rev A2 010205 4-227 RF2371 Preliminary GENERAL PURPOSE AMPLIFIERS 4 4-228 Rev A2 010205