RF2461 CDMA/FM LOW NOISE AMPLIFIER/MIXER 900MHz DOWNCONVERTER RoHS Compliant & Pb-Free Product Package: QFN, 20-Pin, 4x4 ENABLE LO IN VCC2 17 16 1 15 IF2+ MIX GAIN 2 14 IF2- LNA IN 3 13 BYPASS VCC1 4 12 IF1+ GND1B 5 11 IF1- 6 7 8 9 10 MIX IN CDMA/FM (AMPS) Systems Dual-Mode TACS/JCDMA Systems General Purpose Downconverter Commercial and Consumer Systems Portable Battery-Powered Equipment 18 LNA GAIN Applications 19 GND3B 20 ISET1 IP SET ISET2 Complete Receiver Front-End Stepped LNA/Mixer Gain Control Adjustable LNA/Mixer Bias Current Adjustable LNA/Mixer IIP3 Meets IMD Tests with Three Gain States/Two Logic Control Lines LNA OUT IF SEL Features Functional Block Diagram Product Description The RF2461 is a receiver front-end designed for the receive section of dual-mode CDMA/FM cellular applications. It is designed to amplify and downconvert RF signals, while providing 30dB of stepped gain control range. Features include digital control of LNA gain, mixer gain, and power down mode. Another feature of the chip is adjustable IIP3 of the LNA and mixer using an off-chip current setting resistor. Noise figure, IP3, and gain are designed to be compatible with the IS-98B interim standard for CDMA cellular communications. The IC is manufactured on an advanced Silicon Germanium Bi-CMOS process and is assembled in a 4mmx4mm, 20-pin, QFN package. Ordering Information RF2461CDMA/FM Low Noise Amplifier/Mixer 900MHz Downconverter RF2461PCBA-41X Fully Assembled Evaluation Board Optimum Technology Matching® Applied GaAs HBT GaAs MESFET InGaP HBT 9SiGe BiCMOS Si BiCMOS SiGe HBT GaAs pHEMT Si CMOS Si BJT GaN HEMT RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2006, RF Micro Devices, Inc. Rev B6 DS060925 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. 1 of 14 RF2461 Absolute Maximum Ratings Parameter Supply Voltage Input LO and RF Levels Rating Unit -0.5 to +5.0 VDC +6 dBm Operating Ambient Temperature -40 to +85 °C Storage Temperature -40 to +150 °C Parameter Min. Specification Typ. Max. Caution! ESD sensitive device. Exceeding any one or a combination of the Absolute Maximum Rating conditions may cause permanent damage to the device. Extended application of Absolute Maximum Rating conditions to the device may reduce device reliability. Specified typical performance or functional operation of the device under Absolute Maximum Rating conditions is not implied. RoHS status based on EUDirective2002/95/EC (at time of this document revision). The information in this publication is believed to be accurate and reliable. However, no responsibility is assumed by RF Micro Devices, Inc. ("RFMD") for its use, nor for any infringement of patents, or other rights of third parties, resulting from its use. No license is granted by implication or otherwise under any patent or patent rights of RFMD. RFMD reserves the right to change component circuitry, recommended application circuitry and specifications at any time without prior notice. Unit Overall RF Frequency Range Condition T = 25°C, VCC =3.0V 800 869 to 894 1000 MHz 1000 MHz 250 MHz 10 μA 832 to 870 LO Frequency Range 700 954 to 979 722 to 760 IF Frequency Range 0.1 Power Down Current LNA - CDMA/JCDMA Gain LNA Gain=1 14.0 15.0 16.0 dB IPSET=1 13.5 14.5 15.0 dB IPSET=0 1.8 2 dB IPSET=1 1.8 2 dB IPSET=0 Noise Figure Input IP3 +9.0 +11.0 dBm IPSET=1 +7.0 +9.0 dBm IPSET=0 6.5 mA IPSET=1 5.0 mA IPSET=0 Current LNA Bypass CDMA/JCDMA Gain LNA Gain=0 -8 -6 +16.0 +18.0 dBm 0 mA Noise Figure Input IP3 6 Current dB 8 dB 3kΩ balanced load. IIP3 is adjustable. Decreasing R4/R5 will increase IIP3. LO=965MHz@-10dBm, IF=85.38MHz Mixer - CDMA Gain 13 14.5 dB Mixer Preamp ON, Mix Gain=1 4 5.8 dB Mixer Preamp OFF, Mix Gain=0 Noise Figure Input IP3 Current Mixer - JCDMA 2 of 14 5.5 7 dB Mixer Preamp ON, Mix Gain=1 13 14 dB Mixer Preamp OFF, Mix Gain=0 +3.0 +4.0 dBm Mixer Preamp ON, Mix Gain=1 +13.0 +14.0 dBm Mixer Preamp OFF, Mix Gain=0 21 mA Mixer Preamp ON, Mix Gain=1 18 mA Mixer Preamp OFF, Mix Gain=0 3kΩ balanced load. IIP3 is adjustable. Decreasing R4/R5 will increase IIP3. LOIN=741MHz@-4dBm, IF=110MHz 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. Rev B6 DS060925 RF2461 Gain 12 13 dB Mixer Preamp ON, Mix Gain=1 2.5 4.0 dB Mixer Preamp OFF, Mix Gain=0 Noise Figure Input IP3 Current Rev B6 DS060925 5.5 7 dB Mixer Preamp ON, Mix Gain=1 13 14 dB Mixer Preamp OFF, Mix Gain=0 +2.0 +3.0 dBm Mixer Preamp ON, Mix Gain=1 +10.0 +12.0 dBm Mixer Preamp OFF, Mix Gain=0 24 mA Mixer Preamp ON, Mix Gain=1 21 mA Mixer Preamp OFF, Mix Gain=0 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. 3 of 14 RF2461 Parameter Min. Specification Typ. Max. Unit Condition Local Oscillator Input Input Level -10 dBm LO to IF Isolation -70 dB LO to LNA Isolation -60 dB Any gain state. Power Supply Voltage 2.65 3.0 3.15 V LNA High Gain/Mixer High Gain. LNA Gain=1, Mix Gain=1. Assumes 3dB Image filter insertion loss. Cascade High Gain Mode Gain 23.5 26 Noise Figure 28 2.4 Input IP3 -11 -9 Current dB dB 0 26 dBm mA LNA High Gain/Mixer Low Gain. LNA Gain=1, Mix Gain=0. Assumes 3dB Image filter insertion loss. Cascade Mid Gain Mode Gain 16.5 Noise Figure 4.9 dB dB Input IP3 0 dBm Current 23 mA LNA Low Gain/Mixer High Gain. LNA Gain=0, Mix Gain=1. Assumes 3dB Image filter insertion loss. Cascade Low Gain Mode Gain 4 dB Noise Figure 15.5 dB Input IP3 11.8 dBm 22 mA Current LNA Low Gain/Mixer Low Gain. LNA Gain=0, Mix Gain=0. Assumes 3dB Image filter insertion loss. Cascade Ultra-Low Gain Mode Gain -7 -4.5 Noise Figure -3 22.5 Input IP3 +14 +20 Current 18 dB dB 40 dBm mA Cellular CDMA, IPSET=1 Mode LNA GAIN MIX GAIN High Gain 1 1 Recommended for IMD Tests 1 and 2 Mid Gain 1 0 Recommended for IMD Tests 3 and 4 Low Gain 0 1 Recommended for IMD Tests 5 and 6 Ultra-Low Gain 0 0 Alternative Lowest Current Mode for IMD Tests 5 and 6 4 of 14 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. Rev B6 DS060925 RF2461 Pin 1 Function LNA GAIN 2 MIX GAIN 3 LNA IN Description Interface Schematic Controls the bypass feature of the LNA. A logic low (<1.0V) selects the bypass mode. A logic high (>2.0V) turns on the LNA. LNA GAIN Controls the bypass feature of the mixer preamp. A logic low (<1.0V) selects the bypass mode. A logic high (>2.0V) turns on the preamppreamp. MIX GAIN LNA input pin. LNA O U T L N A IN G N D 1B 4 5 VCC1 GND1B 6 7 LNA OUT ISET2 8 ISET1 9 GND3B VCC pin for all circuits except the LO. Buffer/bias circuitry. LNA emitter. This pin provides the DC path to ground for the LNA. A lumped element or a transmission line inductor can be placed between this pin and ground to degenerate the LNA. This will decrease the gain and increase the IP3 of the LNA. As the value of inductance is increased, these effects will become more pronounced. LNA output pin. See pin 3. An external resistor R2 connected to this pin sets the current of the preamp and the mixer. An external resistor R3 connected to this pin sets the current of the LNA when IP SET is high (see pin 19). Ground pin for preamp circuit. A 3.3nH inductor is used between pin 9 and ground to degenerate the mixer preamp. Degenerating the preamp will reduce the gain, increase the IP3 and affect the preamp input impedance. VCC2 M IX IN G N D3B 10 11 12 MIX IN IF1IF1+ 13 14 BYPASS IF2- Rev B6 DS060925 Mixer preamp input pin. See pin 9. Second differential output pin for the first mixer. See pin 12. First differential output pin for the first mixer. Open collector. A current combiner external network performs a differential to single-ended conversion and sets the output impedance. A DC blocking cap must be present if the IF filter input has a DC path to ground. Mixer (IF2+ and IF-) needs to “see” a differential impedance between 2kΩ to 4kΩ. IF1- IF1+ Bypass pin for the LO bias reference. Second differential output pin for the second mixer. See pin 15. 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. 5 of 14 RF2461 Pin 15 Function IF2+ 16 17 VCC2 LO IN Description Interface Schematic First differential output pin for the second mixer. Open collector. A current combiner external network performs a differential to single-ended conversion and sets the output impedance. A DC blocking cap must be present if the IF filter input has a DC path to ground. Mixer (IF2+ and IF2-) needs to “see” a differential impedance between 2kΩ to 4kΩ. IF2- IF2+ VCC pin for the LO buffer/bias circuitry. LO limiter input pin. LO IN 18 ENABLE This pin is used to enable or disable the RF2461. A logic high (>2.0V) enables the circuitry. A logic low (<1.0V) disables the circuitry. ENABLE 19 IP SET Controls the setting of the LNA current. A logic low (<1.0V) selects the internal resistance (49.5kΩ), resulting in an LNA current of 5mA. A logic high (>2.0V) selects the external resistance at pin 8. IP SET 20 IF SEL Determines which IF port is active. A logic low (<1.0V) activates IF1 and deactivates IF2. A logic high (>2.0V) activates IF2 and deactivates IF1. Mixers are identical. Either IF output may be used for CDMA or AMPS applications. IF SEL Pkg Base GND Ground connection. The backside of the package should be soldered to a top side ground pad which is connected to the ground plane with multiple vias. Package Drawing QFN, 20-PIN, 4x4 -A- 0.15 C A 0.05 C 1.00 0.90 2 PLCS 4.00 0.05 2 PLCS 0.15 C B 3.75 4.00 Dimensions in mm. 12° MAX 0.15 C 2 PLCS -B- -C- 3.75 0.15 C 2 PLCS Note orientation of package. 0.10 M C A B 0.20 NOTES: 1 Shaded lead is Pin 1. Dimension applies to plated terminal: 2 to be measured between 0.02 mm and 0.25 mm from terminal end. 2 0.65 0.30 0.60 0.24 TYP 4 PLCS 2.10 SQ. 0.75 0.50 0.23 0.13 4 PLCS 0.50 6 of 14 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. Rev B6 DS060925 RF2461 Application Schematic NOTE: Microstrip Inductor, Z0 = 50 Ω, L = 102 mils suggested compared values. VCC2 VCC1 100 pF See Note 8 56 Ω L2 100 pF See Note 8 See Note 7 LO IN ENABLE C2 IP SET IF SEL 20 LNA GAIN 19 18 17 L 16 L1 1 15 2 14 3 13 R C1 IF2+ IF2F i l t e r MIX GAIN See Note 11 4.3 nH C1 LNA IN 16 nH 33 nF See Note 12 BYPASS 100 pF 100 pF 50 Ω μstrip See Note 8 VCC1 L=130 mils W=12 mils Z0=50 Ω 4 12 5 11 See Note 8 C1 L1 6 7 8 9 R 10 See Note 2 C1 0.1 μF VCC1 100 pF 22 kΩ See Note 8 51 Ω* *This resistor improves NF and IIP3 for VCC = 3.0 V. See Note 9 7.5 nH 4 pF See Note 11 50 Ω μstrip See Note 4 47 kΩ See Note 5 3.3 nH See Note 3 C2 33 nF L IF+ IF- See Note 1 620 Ω L2 See Note 10 47 nH See Note 6 F i l t pF 100 eSee Note 8 r VCC1 F NOTES: i 1. DC blocking capacitor. l 2. LNA emitter degenerator. As the value t of inductance is increased, the gain will decrease, and the IIP3 will increase. 3. Mixer preamp degeneration inductor. e As the value of inductance is increased, the gain will decrease, and the IIP3 will increase. 4. An external resistor connected to this r pin sets the current of the preamp and the mixer. Higher resistance to ground results in lower current. See chart at end of datasheet. 5. An external resistor connected to this pin sets the current of the LNA when IPSET is high. Higher resistance to ground results in lower current. See chart at end of datasheet. 6. Mixer input matching inductor. 7. LO input matching resistor. 8. Bypass capacitor. 9. LNA output matching and bias choke. 10. For stability of the LNA. 11. LNA input and output matching. 12. Low pass path to ground for two-tone beat frequency for optimum IIP3 of LNA. Output Interface Network Rev B6 DS060925 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. 7 of 14 RF2461 L1, C1, and R form a current combiner which performs a differential to single-ended conversion at the IF frequency and sets the output impedance. In most cases, the resonance frequency is independent of R and can be set according to the following equation: Where CEQ is the equivalent stray capacitance and capac1 fIF = itance looking into pins 11 and 12. An average value to L1 (C1 + CEQ) 2π 2 use for CEQ is 2.5pF to 3pF. R can then be used to set the output impedance according to the following equation: L2 and C2 serve dual purposes. L2 serves as an output 1 R = ( - 1 ) -1 bias choke, and C2 serves as a series DC block. 4 R OU T RP where ROUT is the desired output impedance and RP is the parasitic equivalent parallel resistance of L1. C1 should be chosen as high as possible (not greater than 15pF), while maintaining an RP of L1 that allows for the desired ROUT. 8 of 14 In addition, L2 and C2 may be chosen to form an impedance matching network if the input impedance of the IF filter is not equal to ROUT. Otherwise, L2 is chosen to be large, and C2 is chosen to be large if a DC path to ground is present in the IF filter, or omitted if the filter is DC blocked. 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. Rev B6 DS060925 RF2461 Evaluation Board Schematic - CDMA LO@965MHz, RF@880MHz, IF@85MHz (Download Bill of Materials from www.rfmd.com.) P2 P1 P1-1 P1-3 1 MIX GAIN P2-1 1 IF SEL 2 GND P2-2 2 IP SET 3 LNA GAIN P2-3 3 ENABLE CON3 447 pS Electrical Delay 0.13 dB Line Loss J1 LO IN P3 P3-1 P3-3 CON3 1 VCC1 2 GND 3 VCC2 C16 100 pF R6 56 Ω 50 Ω μstrip VCC2 VCC1 L8 390 nH C15 100 pF CON3 ENABLE IP SET IF SEL C14 10 pF 50 Ω μstrip 20 19 18 17 16 LNA GAIN 1 15 2 14 3 13 50 Ω μstrip 348 pS Electrical Delay @ 110 MHz 0.03 dB Line Loss J6 IF2 OUT 50 Ω μstrip 50 Ω μstrip 50 Ω μstrip L9 470 nH R5 10 kΩ C13 11 pF MIX GAIN 329 pS Electrical Delay 0.10 dB Line Loss J2 LNA IN 50 Ω μstrip 50 Ω μstrip L1 4.3 nH L2 16 nH 50 Ω μstrip C1 33 nF C2 100 pF 50 Ω μstrip VCC1 4 12 5 11 L=130 mils W=12 mils Z0=50 Ω VCC1 498 pS Electrical Delay 0.15 dB Line Loss J3 LNA OUT 50 Ω μstrip R14 51 Ω Note: R14 improves NF and IIP3 for VCC = 3.0 V C3 0.1 μF 6 8 9 BYPASS 50 Ω μstrip 10 R1 620 Ω 50 Ω μstrip R2 18 kΩ R3 L4 47 kΩ 3.3 nH L6 470 nH C10 11 pF R4 10 kΩ C9 11 pF 50 Ω μstrip L7 390 nH C8 10 pF 348 pS Electrical Delay @ 110 MHz 0.03 dB Line Loss J5 IF1 OUT 50 Ω μstrip VCC1 C5 4 pF C7 100 pF 50 Ω μstrip 50 Ω μstrip C6 33 nF Rev B6 DS060925 C11 100 pF 50 Ω μstrip 50 Ω μstrip C4 100 pF L3 7.5 nH 7 C12 11 pF 50 Ω μstrip L5 47 nH 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. 320 pS Electrical Delay @ 880 MHz 0.10 dB Line Loss J4 MIXER IN 9 of 14 RF2461 Evaluation Board Schematic - JCDMA LO@741MHz, RF@851MHz, IF@110MHz P1-1 P1-3 P1 P2 P3 1 MIX GAIN P2-1 1 IF SEL 1 VCC1 2 GND P2-2 2 IP SET 2 GND 3 LNA GAIN P2-3 3 ENABLE 3 VCC2 CON3 P3-1 P3-3 CON3 447 pS Electrical Delay 0.13 dB Line Loss J1 LO IN VCC2 C16 100 pF R6 56 Ω 50 Ω μstrip VCC1 L8 270 nH C15 100 pF CON3 ENABLE IP SET IF SEL 50 Ω μstrip 50 Ω μstrip C14 7 pF 50 Ω μstrip 20 19 18 17 16 LNA GAIN 1 15 2 14 3 13 50 Ω μstrip L9 330 nH R5 4.3 kΩ C13 9 pF MIX GAIN 329 pS Electrical Delay 0.10 dB Line Loss J2 LNA IN 50 Ω μstrip 50 Ω μstrip L1 4.3 nH L2 16 nH 50 Ω μstrip C1 33 nF C2 100 pF 50 Ω μstrip VCC1 4 12 5 11 L=130 mils W=12 mils Z0=50 Ω VCC1 498 pS Electrical Delay 0.15 dB Line Loss J3 LNA OUT 50 Ω μstrip C3 0.1 μF R14 51 Ω 6 8 9 C12 10 pF BYPASS 50 Ω μstrip 10 L6 330 nH R1 620 Ω 50 Ω μstrip R2 18 kΩ R3 L4 33 kΩ 7.5 nH C10 11 pF R4 4.3 kΩ C9 9 pF 50 Ω μstrip L7 270 nH C8 7 pF 348 pS Electrical Delay @ 110 MHz 0.03 dB Line Loss J5 IF1 OUT 50 Ω μstrip VCC1 Note: R14 improves NF and IIP3 for VCC = 3.0 V C5 4 pF C7 100 pF 50 Ω μstrip 50 Ω μstrip C6 33 nF 10 of 14 C11 100 pF 50 Ω μstrip 50 Ω μstrip C4 100 pF L3 7.5 nH 7 348 pS Electrical Delay @ 110 MHz 0.03 dB Line Loss J6 IF2 OUT 50 Ω μstrip 50 Ω μstrip L5 30 nH 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. 320 pS Electrical Delay @ 880 MHz 0.10 dB Line Loss J4 MIXER IN Rev B6 DS060925 RF2461 Evaluation Board Layout Board Size 2.0" x 2.0" Board Thickness 0.031”, Board Material FR-4, Multi-Layer Rev B6 DS060925 Assembly Top Power Plane 1 Power Plane 2 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. 11 of 14 RF2461 Back 12 of 14 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. Rev B6 DS060925 RF2461 LNA Gain, Noise Figure and IIP3 versus ICC 16.0 15.0 14.0 Mixer (Mixer High Gain, LO=-7dBm) 25.00 5.0 10.0 0.0 8.0 -5.0 6.0 Gain (dB) NF (dB) 4.0 -10.0 IIP3 (dBm) Gain and Noise Figure (dB) 15.00 12.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 5.00 0.00 0.00 -5.00 NF (dB) IIP3 (dBm) -20.00 16.0 -10.00 10.00 15.00 20.00 ICC (mA) 25.00 30.00 35.00 40.00 ICC (mA) Resistor (R3) versus ICC (mA) LNA Only (LNA High Gain) 200.0 -5.00 Gain (dB) -15.00 -20.0 0.0 5.00 10.00 -10.00 -15.0 2.0 180.0 200.0 Resistor (R2) versus ICC - Mixer (Mixer High Gain, LO=2170@-7dBm) 180.0 R3 (kohm) 160.0 160.0 140.0 140.0 Resistor R2 ( kΩ) Resistor R3 (kΩ) 10.00 20.00 10.0 IIP3 (dBm) Gain and Noise Figure (dB) Mixer Gain, Noise Figure and IIP3 versus ICC - IIP3 (dBm) LNA Only (LNA High Gain) 120.0 100.0 80.0 120.0 100.0 80.0 60.0 60.0 40.0 40.0 20.0 20.0 0.0 R2 (kohm) 0.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 10.0 15.0 ICC (mA) 20.0 25.0 30.0 35.0 40.0 ICC (mA) Condition T=25oC, VCC=2.75V, RF=880 and 881MHz, LO=965MHz @-10dBm Rev B6 DS060925 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. 13 of 14 RF2461 14 of 14 7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical support, contact RFMD at (+1) 336-678-5570 or [email protected]. Rev B6 DS060925