RF2948B 0 2.4GHz SPREAD-SPECTRUM TRANSCEIVER Typical Applications • IEEE 802.11b WLANs • High Speed Digital Links • Wireless Residential Gateways • Wireless Security • Secure Communication Links • Digital Cordless Telephones 2 PLCS 0.10 C A IG N S Product Description -A- 2.50 TYP. E S 2 PLCS 0.10 C B 2 PLCS 0.10 C A 9Si Bi-CMOS SiGe HBT InGaP/HBT 0.05 0.00 12° MAX -B-C- SEATING PLANE 2.37 TYP. 4.75 SQ. 0.10 M C A B 0.60 0.24 TYP. 0.30 0.18 2 Pin 1 ID R.20 Shaded lead is pin 1. 3.45 SQ. 3.15 W N E GaAs HBT 0.70 0.65 Dimensions in mm. 0.50 0.30 0.50 Optimum Technology Matching® Applied Si BJT 0.05 C 0.90 0.85 2 PLCS 0.10 C B 3 D The RF2948B is a monolithic integrated circuit specifically designed for direct-sequence spread-spectrum systems operating in the 2.4GHz ISM band. The part includes: a direct conversion from IF receiver with variable gain control; quadrature demodulator; I/Q baseband amplifiers; and, on-chip programmable baseband filters. For the transmit side, a QPSK modulator and upconverter are provided. The design reuses the IF SAW filter for transmit and receive reducing the number of SAW filters required. Two-cell or regulated three-cell (3.6V maximum) battery applications are supported by the part. The part is also designed to be part of a 2.4GHz chipset consisting of the RF2494 LNA/Mixer, one of the many RFMD high-efficiency GaAs HBT PA’s and the RF3000 Baseband Processor. 5.00 SQ. Package Style: QFN, 32-Pin, 5x5 GaAs MESFET Si CMOS Features SiGe Bi-CMOS VREF 1 VCC2 BW CTRL DCFB Q DCFB I VREF1 BUF Q OUT • 45MHz to 500MHz IF Quad Demod RX VGC FO R GaN HEMT 32 31 30 29 28 27 26 25 • On-Chip Variable Baseband Filters • Quadrature Modulator and Upconverter BW Control • 2.7V to 3.6V Operation DC Feedback N O T PD 1 RX EN 2 RX IF BIAS 3 • Part of IEEE802.11b Chipset gm-C LPF Logic DC Feedback REF • 2.4GHz PA Driver gm-C LPF VCC1 4 24 I OUT RX IF IN 5 TX Bias 23 VCC4 gm-C LPF TX IF IN 6 VCC9 7 22 TXQ DATA 21 TXQ BP Ordering Information Σ gm-C LPF TX VGC 8 ÷2 Phase Splitter RF2948B RF2948BTR13 RF2948B PCBA 20 TXI DATA 19 TXI BP 18 IF1 OUT+ 2.4GHz Spread-Spectrum Transceiver 2.4GHz Spread-Spectrum Transceiver (Tape & Reel) Fully Assembled Evaluation Board 17 IF1 OUT15 16 RF OUT VCC5 14 RF LO 13 PA IN 12 PA OUT 11 VCC6 10 VCC8 IF LO 9 Functional Block Diagram RF Micro Devices, Inc. 7628 Thorndike Road Greensboro, NC 27409, USA Tel (336) 664 1233 Fax (336) 664 0454 http://www.rfmd.com NOT FOR NEW DESIGNS Rev A6 040930 11-239 RF2948B Absolute Maximum Ratings Parameter Refer to “Handling of PSOP and PSSOP Products” on page 16-15 for special handling information. Rating Unit -0.5 to +3.6 -0.5 to +3.6 +12 +5 -40 to +85 -40 to +150 VDC VDC dBm dBm °C °C MSL JEDEC level 3 at 240oC Specification Min. Typ. Max. Parameter Refer to “Soldering Specifications” on page 16-13 for special soldering information. 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). IG N S Supply Voltage Control Voltages Input RF Level LO Input Levels Operating Ambient Temperature Storage Temperature Unit Condition T=25 °C, VCC =3.0V, Freq=374MHz, RBW =10kΩ Overall Receiver Cascaded Noise Figure Cascaded Input IP3 Cascaded Input IP3 IF LO Leakage Quadrature Phase Variation 374 50 115 -68 0 Gain 65 Noise Figure IF Input Impedance 4.5 70 5.5 515-j994 MHz dB dB dB dBµV dBµV dBm ° 2 dB VPP % 7.5 dB +1 W IF AMP and Quad Demod ±3 0 1.2 N E Quadrature Amplitude Variation Output P1dB Distortion 500 76 3 35.0 RX VGC =1.2V RX VGC =2.0V Varies with gain. VGC <1.2V VGC>2.0V f=374MHz, LO Power=-10dBm With expected LO amplitude and harmonic content. E S 45 65 0 5.5 D RX Frequency Range Cascaded Voltage Gain dB Ω 1.4<RX VGC <1.8V At 0.70VPP output level. VGC =1.95V=min gain VGC =1.25V max gain Single Sideband, max gain. Single-ended. 374MHz VREF1-15 2 700 VREF1 1 FO THD Output Voltage DC Output Voltage R RX Baseband Amplifiers At 0.707VP-P output level RL >5kΩ, CL <15pF VREF1+15 % mVPP mV 10 35 MHz 5th order Bessel LPF. Set by BW CTRL (RBW) ±10 0.1 ±30 dB % RX Baseband Filters Baseband Filter 3dB Bandwidth N O T Passband Ripple Baseband Filter 3dB Frequency Accuracy Group Delay Group Delay Baseband Filter Ultimate Rejection Output Impedance 11-240 15 ns 400 >80 ns dB 20 Ω At 35MHz, increasing as bandwidth decreases. At 2MHz. Designed to drive>5kΩ, <15pF load. Rev A6 040930 RF2948B Specification Min. Typ. Max. Parameter Unit Condition Transmit Modulator and LPF 0 1 15 Group Delay Ultimate Rejection Input Impedance Input AC Voltage Input P1dB Input DC Offset Requirement IF Frequency Range Differential Output Resistance 400 >80 3 100 200 1.6 45 1.7 1.8 500 22 -18 -26 -30 FO R VGA Gain Range VGA Control Voltage Range VGA Gain Sensitivity VGA Input Impedance RF Mixer Output Impedance VGA/Mixer Conversion Gain VGA/Mixer Output Power N E Harmonic Outputs Transmit VGA and Upconverter ns dB kΩ mVp-p mVp-p V MHz kΩ pF pF ±3 ±1 W Carrier Output dB MHz dB ns E S 0.436 0.4 0 0 0.0185 D Differential Output Capacitance Shunt Output Capacitance I/Q Phase Balance I/Q Gain Balance Conversion Transconductance Any setting 5th order Bessel LPF, Set by BW CTRL At 35MHz, increasing as bandwidth decreases. At 2MHz. Single-ended Linear, Single-ended. Single-ended. For correct operation. dB S dBc Between output pins. Open collector when TX on, Hi Z when TX off Between output pins. From each pin to ground. Single-ended voltage input to differential output current conversion gain. Without external offset adjustments. 374MHz. Compared to modulated signal, 100mVP-P input. dBc 17 1.0 to 2.0 17 515-j994 50 -3 to +14 -9 dB V dB/V Ω Ω dB dBm -4 dBm Positive Slope 374MHz With matching elements. With 50Ω match on the output. 1dB compression - Single Sideband, TX GC=1.0V. (Desired signal power) 1dB compression - Single Sideband, TX GC=2.0V. (Desired signal power) N O T VGA/Mixer Output Power 35 0.1 IG N S Filter Gain Baseband Filter 3dB Bandwidth Passband Ripple Group Delay Rev A6 040930 11-241 RF2948B Parameter Specification Min. Typ. Max. Unit 6 9 12 50 50 dBm dB dBm Ω Ω Condition Transmit Power Amp Linear Output Power Gain Output P1dB Output Impedance Input Impedance 10 Nominal Nominal Power Down Control VCC -0.3V Logical Controls “OFF” Control Input Impedance RX VGC Response TIme RX EN Response TIme TX EN Response TIme VPD to RX Response TIme VPD to TX Response TIme -0.3 0 >1 200 2 330 1.33 50 VCC +0.3V V 0.3 V MΩ ns µs ns ms µs 1050-j1200 -10 RF LO Input 33-j110 -10 2000 VREF1 Buffered Power Supply mA mV V V 1.7 2.7 3.3 3.6 FO N O T 11-242 Ω dBm MHz 1 VREF1+10 1.8 R Voltage Total Current Consumption Sleep Mode Current PA Driver Current RX Current BW (MHz) 9 12-20 20-30 TX Current BW (MHz) 9 12-20 20-30 0 2400 VREF1-10 1.6 N E Source/Sink Current Output Voltage VREF1 Ω dBm MHz W Input Impedance Input Power Range Input Frequency 0 1000 D -15 90 Full step in gain, to 90% of final output level. I/Q output VALID To IF output VALID To I/Q output VALID To IF output VALID The IF LO is divided by 2 and split into quadrature signals to drive the frequency mixers. f=748MHz peak (2x IF Frequency) E S IF LO Input Input Impedance Input Power Range Input Frequency Voltage supplied to the input, not to exceed 3.6V. Voltage supplied to the input. IG N S Logical Controls “ON” µA mA 1 18 65 70 110 85 mA mA mA 95 105 115 136 mA mA mA f=2.04GHz unmatched. VCC =3.3V, Baseband BW 1MHz to 40MHz PD=0, RX EN=1 TX EN=1 Rev A6 040930 RF2948B Pin 1 Function PD Description Interface Schematic This pin is used to power up or down the transmit and receive baseband sections. A logic high powers up the quad demod mixers, TX and RX GmC LPF’s, baseband VGA amps, data amps, and IF LO buffer amp/ phase splitter. A logic low powers down the entire IC for sleep mode. Also, see State Decode Table. VCC 10 kΩ Pins 3, 4, 5 ESD To Logic 3 4 5 RX IF BIAS VCC1 RX IF IN 6 TX IF IN IF input for receiver section. Must have DC-blocking cap. The capacitor See pin 6. value should be appropriate for the IF frequency. For half-duplex operation, connect RX IF IN and TX IF IN signals together after the DC blocking caps, then run a transmission line from the output of the IF SAW. AC coupling capacitor must be less than 150pF to prevent delay in switching RX to TX/TX to RX. Input for the TX IF signal after SAW filter. External DC-blocking cap IF required. For half-duplex operation, connect RX IF IN and TX IF IN sigSAW nals together after the DC-blocking caps, then run a transmission line Filter from the output of the IF SAW. AC coupling capacitor must be less than 150pF to prevent delay in switching RX to TX/TX to RX. D Pin 8 Gain control setting for the transmit VGA. Positive slope. IF LO input. Must have DC-blocking cap. The capacitor value should be appropriate for the IF frequency. LO frequency=2xIF. Quad mod/demod phase accuracy requires low harmonic content from IF LO, so it is recommended to use an n=3 LPF between the IF VCO and IF LO. This is a high impedance input and the recommended matching approach is to simply add a 100Ω shunt resistor at this input to constrain the mismatch. Recommended Matching Network for IF LO C2 150 pF IF VCO IF LO Pin 9 R 100 Ω Power supply for IF LO buffer and quadrature phase network. Power supply for transmitter bias generator. FO VCC8 VCC6 PA OUT N O T 10 11 12 Rev A6 040930 DC Block Pin 7 50 Ω µstrip Power supply for the TX 15dB gain amp and TX VGA. W VCC9 TX VGC IF LO See pin 1. Power supply for RX VGA amplifier, IC logic and RX references. N E 7 8 9 Enable pin for the receiver 15dB gain IF amp and the RX VGA amp. Powers up all receiver functions when PD is high, turns off the receiver IF circuits when low. Also, see State Decode Table. When this pin is a logic “high”, the device is in receive mode. When this pin is a logic “low”, the device is in transmit mode. Shunt resistor of 23.7±1% to ground. Biases IF AMPS. IG N S RX EN E S 2 This is the output transistor of the power amp stage. It is an open collector output. The output match is formed by an inductor to VCC, which supplies DC and a series cap. VCC CBYP 22 nF L Power Amp Output C PA OUT From TX RF Image Filter 14 mA PA IN Bias 11-243 RF2948B Pin 13 Function PA IN 14 VCC5 Description Interface Schematic Input to the power amplifier stage. This is a 50Ω input. Requires DCblocking/tuning cap. Supply for the RF LO buffer, RF upconverter and amplifier. See pin 12. VCC VCC CBYP 22 nF To TX RF Image Filter CBYP 22 nF VCC5 RF OUT From TX VGA 12 mA VB IG N S RF LO From RF VCO 16 RF OUT 17 IF1 OUT- Single-ended LO input for the transmit upconverter. External matching See pin 14. to 50Ω and a DC-block are required. Upconverted Transmit signal. This 50Ω output is intended to drive an See pin 14. RF filter to suppress the undesired sideband, harmonics, and other outof-band mixer products. The inverting open collector output of the quadrature modulator. This pin needs to be externally biased and DC isolated from other parts of IF1 OUT+ the circuit. This output can drive a Balun with IF1 OUT+, to convert to unbalanced to drive a SAW filter. The Balun can be either broadband (transformer) or narrowband (discrete LC matching). Alternatively, just IF1 OUT+ can be used to drive a SAW single-ended with an RF choke (high Z at IF) from VCC to IF1 OUT-. E S RF LO D 15 CBLOCK 22 pF IF1 OUT+ The non-inverting open collector output of the quadrature modulator. This pin needs to be externally biased and DC isolated from other parts of the circuit. This output can drive a Balun with IF1 OUT-, to convert to unbalanced to drive a SAW filter. The Balun can be either broadband (transformer) or narrowband (discrete LC matching). Alternatively, just IF1 OUT+ can be used to drive a SAW single-ended with an RF choke (high Z at IF) from VCC to IF1 OUT+. 19 TXI BP 20 21 TXI DATA TXQ BP This is the in-phase modulator bypass pin. A 10nF capacitor to ground is recommended. I input to the baseband 5 pole Bessel LPF for the transmit modulator. 22 23 24 TXQ DATA VCC4 I OUT 25 Q OUT 26 VREF1 BUF 27 DCFB I 28 DCFB Q 29 BW CTRL 30 VCC2 See pin 17. R This is the quadrature phase modulator bypass pin. A 10nF capacitor to ground is recommended. Q input to the baseband 5 pole Bessel LPF for the transmit modulator. FO N O T 11-244 N E W 18 IF1 OUT- Power supply for quadrature modulator. Baseband analog signal output for in-phase channel. 700mVP-P linear output. Baseband analog signal output for quadrature channel. 700mVP-P linear output. Buffered version of the VREF1 output. See pin 31. Sink/Source current <1mA. DC feedback capacitor for in-phase channel. Requires capacitor to ground. (22nF recommended) DC feedback capacitor for quadrature channel. Requires decoupling capacitor to ground. (22nF recommended) This pin requires a resistor to ground to set the baseband LPF bandwidth of the receiver and transmit GmC filter amps. Supply for the I and Q baseband and GmC filters. This pin should be bypassed with a 10nF capacitor. Rev A6 040930 RF2948B Pin 31 Function VREF 1 32 Pkg Base RX VGC Interface Schematic This is a bypass pin for the bias circuits of the GmC filter amps and for I/Q inputs. No current should be drawn from this pin (<10µA). 1.7V nominal. Receiver IF and baseband amp gain control voltage. Negative slope. Ground for all circuitry in the device. A very low inductance from the base to the PCB groundplane is essential for good performance. Use an array of vias immediately underneath the device. This diode structure is used to provide electrostatic discharge protection to 3kV using the Human body model. The following pins are protected: 1-4, 7, 8, 10, 19-32. VCC N O T FO R N E W D E S IG N S ESD Description Rev A6 040930 11-245 RF2948B Input Pins PD RX EN 0 x 1 1 1 0 State Decode Table Sleep Mode Receive Mode Transmit Mode Internally Decoded Signals BB EN RXIF EN TXRF EN 0 0 0 1 1 0 1 0 1 NOTES BB_EN Enables: Quad Demodulator mixers Baseband Amps and gm-C LPF’s IF LO buffer/phase splitters RXIF_EN Enables: RX IF VGA amplifiers TXRF_EN Enables: E S Front-end IF amplifier (RX) IG N S TX_LPF’s and buffers TX VGA D Front-end IF amplifier (TX) RF upconverter and buffer W PA driver RF LO buffer N O T FO R N E Quad Modulator mixers 11-246 Rev A6 040930 RF2948B RX VGC VREF 1 VCC2 BW CTRL DCFB Q DCFB I VREF1 BUF Q OUT Detailed Functional Block Diagram 32 31 30 29 28 27 26 25 IG N S BW Control DC Feedback PD 1 RX EN 2 gm-C LPF Logic RX IF BIAS 3 DC Feedback E S REF gm-C LPF 24 I OUT D VCC1 4 TX Bias W RX IF IN 5 N E TX IF IN 6 VCC9 7 gm-C LPF Σ gm-C LPF R Phase Splitter 20 TXI DATA FO 19 TXI BP 18 IF1 OUT+ 10 11 12 13 14 15 16 IF LO VCC8 VCC6 PA OUT PA IN VCC5 RF LO RF OUT 17 IF1 OUT- 9 N O T Rev A6 040930 22 TXQ DATA 21 TXQ BP TX VGC 8 ÷2 23 VCC4 11-247 RF2948B Theory of Operation RECEIVER RX IF AGC/Mixer Being essentially high impedance, RX IF IN responds to the input voltage (rather than power), and amplifies that voltage by the gain specified in the datasheet, then presents the output voltage at a high impedance (after downconversion). For characterization purposes, a 50Ω shunt resistor is placed on the IF signal path, before AC-coupling to the input. A 50Ω signal source is applied directly across the shunt resistor, through a coaxial test lead. The signal source sees the shunt resistor and therefore a low SWR. Voltage gain is then simply the ratio of the output voltage to the input voltage. N E R The IF to BB mixers are double-balanced, differential in, differential out, mixers with negligible conversion gain. The LO for each of these mixers is shifted 90° so that the I and Q signals are separated in the mixers. IG N S E S IF LO Buffer The IF LO input has a limiting amplifier before the phase splitting network to amplify the signal and help isolate the VCO from the IC. Also, the LO input signal must be twice the desired intermediate frequency. This simplifies the quadrature network and helps reduce the LO leakage onto the RX_IF input pin (since the LO input is now at a different frequency than the IF). The amplitude of this input needs to be between -15dBm and 0dBm. Excessive IF LO harmonic content affects phase balance of the modulator and demodulator so it is recommended that IF LO harmonics be kept below -30dBc. N O T FO RX Baseband Amps, Filters, and DC Feedback At baseband frequency, there are fully integrated gm-C low pass filters to further filter out-of-band signals and spurs that get through the SAW filter, anti-alias the signal prior to the A/D converter, and to band-limit the signal and noise to achieve optimal signal-to-noise ratio. The 3dB cut-off frequency of these low pass filters is programmable with a single external resistor, and continuously variable from 1MHz to 35MHz. A five-pole Bessel type filter response was chosen because it is optimal for data systems due to its flat delay response and clean step response. Butterworth and Chebychev type filters ring when given a step input making them less ideal for data systems. The filter outputs drive the linear 700mVPP signal off-chip. LO INPUT BUFFERS RF LO Buffer The RF LO input has a limiting amplifier before the mixer on both the RF2494 (RX) and RF2948B (TX). This limiting amplifier design and layout is identical on both ICs, which will make the input impedance the same as well. Having this amplifier between the VCO and mixer minimizes any reverse effect the mixer has on the VCO, expands the range of acceptable LO input levels, and holds the LO input impedance constant when switching between RX and TX. The LO input power range is -18dBm to +5dBm, which should make it easy to interface to any VCO and frequency synthesizer. D W The front end of the IF AGC starts with a single-ended input and a constant gain amp of 15dB. This first amp stage sets the noise figure and input impedance of the IF section, and its output is taken differentially. The rest of the signal path is differential until the final baseband output, which is converted back to single-ended. Following the front end amp are multiple stages of variable gain differential amplifiers, giving the IF signal path a gain range of 4.0dB to 70.0dB. The noise figure (in max gain mode) of the IF amplifiers is 5dB, which should not degrade the system noise figure. DC feedback is built into the baseband amplifier section to correct for input offsets. Large DC offsets can arise when a mixer LO leaks to the mixer input and then mixes with itself. DC offsets can also result from random transistor mismatches. A large external capacitor is needed for the DC feedback to set the high pass cutoff. 11-248 Rev A6 040930 RF2948B IG N S +6dBm PA Driver The SSB output of the upconverter is -6dBm of linear power. The image filter should have at most 4dB of insertion loss while removing the image, LO, 2LO and any other spurs. The filter output should supply the PA driver input -10dBm of power. The PA driver is a one-stage class A amplifier with 10dB gain and capable of delivering 6dBm of linear power to a 50Ω load, and has a 1dB compression point of 12dBm. For lower power applications, this PA driver can be used to drive a 50Ω antenna directly. R N E W D TX VGA Being essentially high impedance, TX IF IN responds to the input voltage (rather than power), and amplifies that voltage by the gain specified in the datasheet, then presents the output voltage at a 50Ω impedance (after upconversion). For characterization purposes, a 50Ω shunt resistor is placed on the IF signal path, before AC-coupling to the input. A 50Ω signal source is applied directly across the shunt resistor, through a coaxial test lead. The signal source sees the shunt resistor and therefore a low SWR. Voltage gain is then the same as power gain, simply the difference in dB between the output power and the input power. TX Upconverter The IF to RF upconverter is a double-balanced differential mixer with a differential to single-ended converter on the output to supply 0dBm peak linear power to the image filter. The upconverted SSB signal should have -6dBm power at this point, and the image will have the same power, but due to the correlated nature of the signal and image, the output must support 0dBm of linear power to maintain linearly. E S TRANSMITTER TX LPF and Mixers The transmit section starts with a pair of 5-pole Bessel filters identical to the filters in the receive section and with the same 3dB frequency. These filters pre-shape and band-limit the digital or analog input signals prior to the first upconversion to IF. These filters have a high input impedance and expect an input signal of 100mVPP typical. Following these low pass filters are the I/Q quadrature upconverter mixers. Each of these mixers is half the size and half the current of the RF to IF downconverter on the RF2494. Recall that this upconverted signal may drive the same SAW filter (in half-duplex mode) as the RF2494 and therefore share the same load. Having the sum of the two BB to IF mixers equal in size and DC current to the RF to IF mixer, will minimize the time required to switch between RX and TX, and will facilitate the best impedance match to the filter. N O T FO The AGC after the SAW filter starts with a switch and a constant gain amplifier of 15dB, which is identical to the circuitry on the receive IF AGC. This was done so that the input impedance will remain constant for different gain control voltages. Following this 15dB gain amplifier is a single stage of gain control offering 15dB gain range. The main purpose of adding this variable gain is to give the system the flexibility to use different SAW filters and image filters with different insertion loss values. This gain could also be adjusted real time, if desired. Rev A6 040930 11-249 RF2948B IL = 1-3 dB 2.4 to 2.483 GHz RF Micro Devices 2.4 GHz ISM Chipset RX VGC RF2948B RF2494 SSOP-16 EPP Gain Select OUT Q SAW IL = 10 dB max RX RX LNA Dual Gain Modes IF Amp TX OUT I Filter 2.4 to 2.483 GHz RF VCO Dual Frequency Synthesizer IF VCO x2 IG N S TX T/R Switch RF3000 Base Band Amp. Active Selectable LPF (fC = 1 MHz to 40 MHz) +45° -45° Filter 10 dBm PA Driver E S RF2189 Σ I INPUT Filter Selectable LPF Q INPUT TX VGC D IL = 1-3 dB 2.4 to 2.483 GHz N O T FO R N E W Figure 1. Entire Chipset Functional Block Diagram 11-250 Rev A6 040930 RF2948B Evaluation Board Schematic (Download Bill of Materials from www.rfmd.com.) R43 10 Ω VCC C68 100 pF VREF1 BUF C65 10 nF R42 10 kΩ C58 22 nF C57 22 nF J2 Q OUT RX VGC 32 C77 100 pF J1 X/TX IF IN R10* 0Ω 28 27 26 1 24 2 23 3 22 4 21 5 C76 100 pF R61 220 Ω TX VGC J6 IF OUT 10 11 12 R28* 270 kΩ VCC R62 51 Ω C70 100 pF 2 VCC P1-3 3 TX VGC J10 PA OUT CON3 P3 1 P3-1 P2-3 C20 10 nF P2-4 RX/TX EN 3 PD RX VGC 4 CON4 L16 3.9 nH *Configured for RX Demod and TX Cascaded Evaluation Evaluate Populate TX Mod Out R11 R62 N/A TX Upconverter R10 R9, R61 R56 to 0 R48 10 Ω VCC C54 22 pF R45 47 Ω R54 10 Ω VCC L14 33 nH C43 1 nF R39 2.2 kΩ L15 27 nH C44 12 pF C50 3 pF FL2 374 MHz GND J8 RF LO L12 33 nH 50 Ω µstrip R5 0Ω OUT GND IN R6* 0Ω 50 Ω µstrip Unpopulate Changes J9 PA IN J7 RF OUT N O T FO R C19 100 pF 16 50 Ω µstrip R7 0Ω R8* 0Ω GND 2 C95 22 pF N E C12 10 nF C40 22 pF 50 Ω µstrip VREF1 BUF GND 2 CON2 P2-2 15 D P1-2 W GND P2 1 14 VCC P1 C82 100 pF 13 C60 10 nF 50 Ω µstrip 1 C91 5 pF C90 5 pF C40 22 pF R27 10 Ω VCC C24 10 nF J5 TXI DATA 17 9 C69 10 nF R32 47 Ω R11* 0Ω C48 1 nF 18 8 50 Ω µstrip J11 IF LO R9 0Ω C47 1 nF E S R56 130 Ω J4 TXQ DATA 19 7 C74 10 nF VCC C52 10 nF 20 6 VCC J3 I OUT 25 IN VCC R1 51 Ω RX/TX EN R44 23.7k, 1% 29 OUT C73 100 pF R49 10 Ω 30 IG N S PD C72 10 nF 31 Rev A6 040930 11-251 RF2948B Evaluation Board Layout Board Size 2.2” x 2.1” N O T FO R N E W D E S IG N S Board Thickness 0.031”, Board Material FR-4, Multi-Layer 11-252 Rev A6 040930 RF2948B RX Voltage Gain versus VGC and VCC (Temp=25oC; RX IF 75.00 RX Gain versus IF LO Amplitude and Temp (VCC=3V; RX IN=375MHz; I and Q out ∼ 300mVP-P IF LO=748MHz @ -10dBm) 70.00 Gain, 2.7V 65.00 Gain, 3V 60.00 Gain, 3.3V VGC=1.6V; RX IF IN=375MHz, I and Q OUT~650mVP-P; IF LO=748MHz) 41.5 41.0 40.5 55.00 40.0 50.00 Gain (dB) 40.00 35.00 30.00 39.5 39.0 Gain, 85°C 20.00 38.0 15.00 37.5 10.00 5.00 37.0 0.00 -5.00 36.5 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 RX IQ Amplitude and Phase Error versus IF LO Amplitude and Temp Ampl. Err, 25°C Ampl. Err, 85°C Ampl. Err, -40°C Phase Err, 25°C Phase Err, 85°C Phase Err, -40°C 0.8 W 0.5 N E 2.5 0.1 1250.0 2 1150.0 R 1100.0 1050.0 1000.0 950.0 900.0 850.0 1.5 800.0 1 750.0 700.0 0.5 650.0 600.0 0 -5.0 0.0 1.2 5.0 FO -10.0 MHz; IF LO = 748 MHz at -10 dBm) 1200.0 3 -15.0 1.3 1.4 1.5 LO Amplitude (dBm) 1.6 1.7 1.8 1.9 2.0 RX VGC (VDC) RX 3dB BW versus RBW (Temp=Ambient, VCC=3.15V, VGC=1.6V, TX 3dB BW Point versus RBW (Broadband 50Ω match on IFOUT, Temp=Ambient, VCC=3.15V, GCTX=1.5V, I&Qin=100mVP-P, IFLO=560MHz@-10dBm) RX IFIN =-67dBm, IF LO=560MHz@-10dBm) 50.0 45.0 N O T 30.0 5.0 1300.0 4 VOUT (mVP-P) 0.6 -20.0 0.0 1400.0 3.5 -25.0 -5.0 1350.0 4.5 0.7 -30.0 -10.0 D 0.9 0.0 -15.0 RX OP1dB versus VGC and Temp (VCC = 3 V; RX IFIN = 375 5 0.2 -20.0 E S 1.0 0.3 -25.0 LO Ampl. (dBm) (VCC=3V; RX VGC=1.6V; RX IF IN=375MHz, I&Q OUT~650mVP-P; IF LO=748MHz) 0.4 Gain, -40°C -30.0 RX VGC (VDC) Amplitude Error (dB) Gain, 25°C 38.5 25.00 IG N S Gain (dB) 45.00 40.0 3dB BW Point [MHz] 3 dB BW Point [MHz] 25.0 20.0 15.0 10.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 5.0 0.0 0.0 1.0 10.0 100.0 RBW [kΩ] Rev A6 040930 1000.0 1.0 10.0 100.0 1000.0 RBW [kΩ] 11-253 RF2948B Modulator Amplitude Error and Image Suppression versus IF LO Amplitude and Temp (VCC=3V; IF LO=748MHz; IQ IN=1MHz @ 100mVP-P) 1.0 28.0 54.0 27.5 48.0 27.0 0.7 42.0 26.5 0.6 36.0 0.5 30.0 0.4 24.0 0.3 18.0 24.5 0.2 12.0 24.0 0.1 6.0 23.5 0.0 23.0 Ampl.Err, 25°C Ampl. Err, 85°C Ampl. Err, -40°C Image Supp, 25°C Image Supp, 85°C Image Supp, -40°C LO Supp, 85°C 0.0 -30.0 -26.0 -22.0 -18.0 -14.0 -10.0 -6.0 -2.0 2.0 6.0 LO Supp, -40°C 26.0 25.5 25.0 -30.0 LO Amplitude (dBm) -18.0 -14.0 -10.0 -6.0 -2.0 2.0 6.0 E S 8.0 14.0 13.0 12.0 11.0 10.0 9.0 6.0 Gain, 2.7V 4.0 D Gain, 3V Gain, 3.3V 2.0 0.0 8.0 7.0 6.0 5.0 4.0 3.0 -2.0 -3.0 -4.0 -5.0 -6.0 0.4 0.6 0.8 1.0 1.2 1.4 1.6 -4.0 -6.0 -8.0 -10.0 -12.0 -14.0 -16.0 Gain, 25°C -18.0 Gain, 85°C -20.0 Gain, -40°C -22.0 1.8 2.0 2.2 -26.0 2.4 FO 0.2 R 2.0 1.0 0.0 -1.0 Gain (dB) W -2.0 N E Gain (dB) -22.0 Upconverter Voltage Gain versus RF LO Amplitude and Temp (VCC=3V; TX VGC=1.6V; TX IF IN=374MHz@-35dBm, RF LO=2068MHz) TX IF IN=374MHz @ -35dBm, RF LO=2068MHz @ -5dBm) -22.0 -18.0 -14.0 -10.0 -6.0 -2.0 2.0 6.0 TX VGC (VDC) LO Amplitude (dBm) Upconverter Output P1dB versus RF LO Amplitude and Temp (VCC=3V; TX VGC=1.6V; TX IF IN=374MHz, RF LO=2068MHz) Upconverter Output P1dB versus VGC and VCC (Temp=25oC; 0.0 TX IF IN=374MHz, RF LO=2068MHz @ -5dBm) -2.0 N O T -2.0 -4.0 -6.0 -2.5 OP1dB, 2.7V -3.0 OP1dB, 3V -3.5 OP1dB, 3.3V -4.0 -8.0 -4.5 -10.0 -5.0 OP1dB (dBm) Gain (dB) -26.0 LO Ampl (dBm) Upconverter Voltage Gain versus VGC and VCC (Temp=25oC; -12.0 -14.0 -16.0 -6.0 -6.5 -7.0 -8.0 -20.0 OP1dB, 25°C -22.0 OP1dB, 85°C -24.0 OP1dB, -40°C -8.5 -9.0 -9.5 -26.0 -26.0 -5.5 -7.5 -18.0 -10.0 -22.0 -18.0 -14.0 -10.0 -6.0 LO Amplitude (dBm) 11-254 IG N S 0.8 LO Supp, 25°C LO Supp (dBc) 0.9 Amplitude Error (dB) Modulator LO Suppression versus IF LO Amplitude and Temp (VCC=3V; IF LO=748MHz; IQ IN=1 MHz @ 100mVP-P) 60.0 -2.0 2.0 6.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 TX VGC (VDC) Rev A6 040930 RF2948B PA Output P1dB versus VCC and Temp (PA IN=2442MHz @ -30dBm) (PA IN=2442MHz) 15.0 14.5 14.0 13.5 13.0 OP1dB (dBm) 12.5 12.0 11.5 11.0 10.5 Gain, 25°C 10.0 Gain, 85°C 9.5 Gain, -40°C 9.0 2.7 3.0 IG N S Gain (dB) PA Gain versus VCC and Temp 10.1 10.0 9.9 9.8 9.7 9.6 9.5 9.4 9.3 9.2 9.1 9.0 8.9 8.8 8.7 8.6 8.5 8.4 8.3 8.2 8.1 8.0 2.7 3.3 3.0 OP1dB, 85°C OP1dB, -40°C 3.3 VCC (VDC) N O T FO R N E W D E S VCC (VDC) OP1dB, 25°C Rev A6 040930 11-255 N O T FO R N E W D E S IG N S RF2948B 11-256 Rev A6 040930