RF2423 5 100mW SPREAD-SPECTRUM TRANSMITTER IC Typical Applications • Digital and Analog Communication Systems • GMSK, QPSK, DQPSK, QAM Modulation • Spread-Spectrum Communication Systems • AM, SSB, DSB Modulation • Portable Battery-Powered Equipment N E W The RF2423 is a monolithic integrated transmitter IC capable of universal direct modulation for UHF AM, PM, or compound carriers. The transmitter may be used stand-alone for applications requiring not more than 100mW output power, or may be used to drive a final power amplifier. The maximum output level is 100mW, and is adjustable over a 25dB range by a single positive voltage. This low-cost IC implements differential amplifiers for the modulation inputs, 90 degree carrier phase shift network, carrier limiting amplifiers, two matched doubly-balanced mixers, variable gain summing amplifier for level control, and 100mW linear (class AB) output amplifier. .157 .150 1 Si Bi-CMOS SiGe HBT GC PHASE ! 1 2 POWER CONTROL Si CMOS .050 .244 .228 16 STAND BY 15 VDD2 14 VDD3 GND2 4 13 GND3 LO IN 5 GND1 6 I REF 7 I SIG 8 N O T 3 12 RF OUT 8 °MAX 0°MIN .050 .016 .010 .007 Package Style: SOP-16 Features • 100mW Output Power Into 50Ω • 25dB Gain Control Range • Excellent Phase & Amplitude Balance • Digitally Controlled Stand-By Mode • 800MHz to 1000MHz Operation 11 GND4 Σ 10 Q REF 9 Q SIG Functional Block Diagram Rev A3 001218 .065 .043 • Single 5V Power Supply VDD1 -45° +45° 5 GaAs MESFET FO R GaAs HBT .010 .004 .393 .386 Optimum Technology Matching® Applied Si BJT .018 .014 MODULATORS AND UPCONVERTERS D E S IG N S Product Description Ordering Information RF2423 RF2423 PCBA 100mW Spread-Spectrum Transmitter IC 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 5-35 RF2423 Absolute Maximum Ratings Parameter Supply Voltage Power Down Voltage (VPD) Input LO and RF Levels Operating Ambient Temperature Storage Temperature Unit VDC VDC dBm °C °C Specification Min. Typ. Max. 800 to 1000 0 to +6 55-j120 Modulation Input Frequency Range Reference Voltage (VREF) Modulation for 100mW Output Power (I & Q) Maximum Modulation (I & Q) Quadrature Phase Error Input Impedance DC Offset (I & Q) VREF ±2.5 ±3 3000 40 +22 -15 25 22 FO R Output Impedance Output VSWR Second Harmonic Output Other Harmonics Output Sideband Suppression Carrier Suppression Unit MHz dBm Ω Condition +22 -10 50 2:1 -45 <-20 35 30 915MHz MHz V V 200 N E W Output Power DC to 100 2.0 to 3.0 VREF ±2 V ° Ω mV VDD =5.3V, VGC =5.3V, LO power=0dBm, LO frequency=915MHz, SSB, I/Q=2.0VP sine wave, VREF =3V +5 dBm dBm Ω dBc dBc dB dB VGAIN =0V Modulation DC offset can be externally adjusted for optimum suppression. Carrier suppression is then typically better than 40dB. Output Level Control Control Range Control Voltage Control Input Current N O T MODULATORS AND UPCONVERTERS Frequency Range Power Level Input Impedance RF Output 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). T=25 °C, VDD =5.3V, VGC =5.3V Carrier Input (LO IN) 5 Caution! ESD sensitive device. D E S IG N S Parameter Rating -0.5 to +7.5 VDD +0.4 +6 -40 to +85 -40 to +150 25 1 to 4 <1.5 dB V mA <100 >50 VCC 0 ns kΩ V V Threshold voltage; Part is turned “ON” Threshold voltage; Part is turned “OFF” 5 4.5 to 6.0 110 50 2 V V mA mA mA Specifications Operating limits Total, 100mW output power Total, minimum output power Standby mode Standby Mode Turn On/Off Time STANDBY Input Impedance Power Down “ON” Power Down “OFF” Power Supply Voltage Current 5-36 60 170 20 Rev A3 001218 RF2423 3 VDD1 4 GND2 5 LO IN GND1 7 I REF I SIG N O T 8 9 10 This pin adjusts the phase of the I/Q signals. However, the control is very sensitive and hard to control. Control voltage change for a few degrees adjustment is in the order of 10mV. Device to device and temperature variation are not characterized. Therefore it is not recommended to use this pin; leave it not connected. Do NOT connect it to ground. For compensating large errors in the I/Q signals supplied to the device or in control loops, this pin may prove useful. Power supply to all circuits except the RF output stages. It is recommended to put some RF decoupling on this pin, though it is not critical. An optional 0.1µF capacitor is required if no other low frequency bypass capacitor is nearby. Ground connection for the gain controlled RF amplifier. Keep traces physically short and connect immediately to ground plane for best performance. Modulator LO input. A series 22nH inductor can be used for matching. This pin is NOT internally DC blocked. An external blocking capacitor must be provided if the pin is connected to a device with DC present. A DC path to ground (i.e. an inductor or resistor to ground) is, however, acceptable at this pin. If a blocking capacitor is required, a value of 33pF is recommended. Ground connection for the baseband, LO and mixer circuits. Keep traces physically short and connect immediately to ground plane for best performance. Reference voltage for the I mixer. This voltage should be the same as the DC voltage supplied to the I SIG pin. To obtain a carrier suppression of better than 25dB it may be tuned ±0.15V (relative to the I SIG DC voltage). Without tuning, it will typically be better than 25dB. Input impedance of this pin is about 3kΩ. FO R 6 Interface Schematic Gain control of the RF amplifier. This pin can be used to control the output power over a 25dB range. Output power is the lowest when the control voltage is 1V or lower, and the highest when set to 4V or higher. When a fixed maximum output level is needed, it is recommended to connect this pin to VDD. Q SIG Q REF Rev A3 001218 5 kΩ GC 10 kΩ PHASE Baseband input to the I mixer. This pin is DC coupled. Maximum output power is obtained when the input signal has a peak to peak amplitude of 5V. The DC level supplied to this pin should be VDD2/2. Input impedance of this pin is about 3kΩ. Baseband input to the Q mixer. This pin is DC coupled. Maximum output power is obtained when the input signal has a peak to peak amplitude of 5V. The DC level supplied to this pin should be VDD2/2. Input impedance of this pin is about 3kΩ. 5 MODULATORS AND UPCONVERTERS PHASE Description D E S IG N S 2 Function GC N E W Pin 1 LO IN I REF 4 kΩ I SIG 2 kΩ 2 kΩ 1 kΩ 1 kΩ Q REF Q SIG 2 kΩ 2 kΩ 1 kΩ 1 kΩ Reference voltage for the Q mixer. This voltage should be the same as the DC voltage supplied to the Q SIG pin. To obtain a carrier suppression of better than 25dB it may be tuned ±0.15V (relative to the Q SIG DC voltage). Without tuning it will typically be better than 25dB. Input impedance of this pin is about 3kΩ. 5-37 RF2423 Pin 11 Function GND4 12 RF OUT Description Interface Schematic Ground connection for the RF driver and output stage. Keep traces physically short and connect immediately to ground plane for best performance. Having a good ground connection on this pin is extremely important due to the high RF levels in the circuits connected to this pin. 50Ω RF output. This pin is not internally DC blocked and an external blocking capacitor of 22pF is needed. VDD RF OUT 15 VDD2 16 STANDBY D E S IG N S VDD3 N E W 14 Ground connection for the RF driver and output stage. Keep traces physically short and connect immediately to ground plane for best performance. Having a good ground connection on this pin is extremely important due to the high RF levels in the circuits connected to this pin. Power supply for the RF output stage. A 33pF external bypass capacitor is required and an optional 0.1µF will be required if no other low frequency bypass capacitors are nearby. The trace length between the pin and the bypass capacitors should be minimized. The ground side of the bypass capacitors should connect immediately to ground plane. Having good bypassing on this pin is especially important because of the high levels of RF signal on the circuits connected to this pin. Power supply for the RF driver stage. A 33pF external bypass capacitor is required and an optional 0.1µF will be required if no other low frequency bypass capacitors are near by. The trace length between the pin and the bypass capacitors should be minimized. The ground side of the bypass capacitors should connect immediately to ground plane. Having good bypassing on this pin is especially important because of the high levels of RF signal on the circuits connected to this pin. Standby mode control. When this pin is 0V all circuits are turned off, and when this pin is VDD all circuits are operating. This is a high impedance input, internally connected to the gate of a few transistors. To minimize current consumption in power down mode, this pin should be as close to 0 V as possible, or even a little negative. Turn-on voltage of some parts of the circuit may be as low as 0.0 V. In order to maximize output power this pin should be as close to VDD as possible during normal operation. FO R GND3 N O T MODULATORS AND UPCONVERTERS 5 13 5-38 Rev A3 001218 RF2423 Application Schematic CMOS 1 2 VDD STANDBY 16 POWER CONTROL VDD 15 Note 1 3 14 4 13 100 nF 5 VREF 6 R -45° 22 pF 11 10 Σ C I INPUT 8 C RF OUTPUT 12 +45° VREF 5 R 7 R 100 nF D E S IG N S 22 nH LO INPUT Note 1 100 nF C R 9 MODULATORS AND UPCONVERTERS GAIN CONTROL Q INPUT C 33 pF SMD capacitor mounted as close to the package pin as possible, grounded through via to the ground plane with minimum inductance. NOTE 2: The values of R and C depend on the lowest frequency of the baseband signal. N O T FO R N E W NOTE 1: Rev A3 001218 5-39 RF2423 Evaluation Board Schematic (Download Bill of Materials from www.rfmd.com.) P1 P2 1 QSIG P2-1 1 LEVEL P1-2 2 QREF P2-2 2 PHASE P1-3 3 IREF 3 GND P1-4 4 ISIG P2-4 4 VDD 5 GND P2-5 5 STBY P2-1 C4 100 nF 5 2423400 Rev - 1 MODULATORS AND UPCONVERTERS C5 100 nF P2-2 2 P2-4 16 POWER CONTROL 3 C7 100 pF 5 L1 22 nH P1-3 7 P1-4 8 C2 36 pF P2-4 C6 100 nF -45° +45° 12 11 Σ C1 36 pF RF OUT J2 R3 0Ω P1-2 10 P1-1 9 R4 22 Ω N O T FO R R1 22 Ω P2-5 13 N E W R2 33 Ω 6 C3 36 pF 15 14 4 LO IN J1 D E S IG N S P1-1 5-40 Rev A3 001218 RF2423 Evaluation Board Layout 1.25” x 1.25” D E S IG N S Board Thickness 0.031”; Board Material FR-4 N O T FO R N E W MODULATORS AND UPCONVERTERS 5 Rev A3 001218 5-41 N O T FO R N E W 5 D E S IG N S MODULATORS AND UPCONVERTERS RF2423 5-42 Rev A3 001218