RF2131

RF2131 2 Typical Applications • AMPS/ETACS Cellular Handsets • CDPD Portable Data Cards • 900MHz ISM Band Equipment • Commercial and Consumer Systems • Portable Battery-Powered Equipment HIGH EFFICIENCY AMPS/ETACS AMPLIFIER 2 POWER AMPLIFIERS Product Description The RF2131 is a high-power, high-efficiency amplifier IC. The device is manufactured on an advanced Gallium Arsenide Heterojunction Bipolar Transistor (HBT) process, and has been designed for use as the final RF amplifier in AMPS and ETACS handheld equipment, spread spectrum systems, CDPD, and other applications in the 800MHz to 950MHz band. On-board power control provides over 30dB of control range with an analog voltage input, and provides power down with a logic "low" for standby operation. Although it is intended for class C operation, linear class AB operation can be achieved by raising the bias level. The device is self-contained with 50 Ω input and the output can be easily matched to obtain optimum power and efficiency characteristics. Optimum Technology Matching® Applied Si BJT Si Bi-CMOS 0.158 0.150 0.021 0.014 -A0.009 0.004 0.392 0.386 0.069 0.064 0.050 0.244 0.230 8° MAX 0° MIN 0.010 0.008 0.060 0.054 0.035 0.016 ü Package Style: Standard Batwing GaAs HBT SiGe HBT GaAs MESFET Si CMOS Features • Single 4.0V to 7.0V Supply • 1.2W Output Power • 25dB Gain With Analog Gain Control • 64% Efficiency • Digitally Controlled Power Down Mode • 800MHz to 950MHz Operation PC 1 NC 2 VCC2 3 GND 4 GND 5 GND1 6 RF IN 7 VCC1 8 BIAS 16 NC 15 RF OUT 14 RF OUT 13 GND 12 GND 11 RF OUT 10 RF OUT 9 NC Ordering Information RF2131 RF2131 PCBA High Efficiency AMPS/ETACS Amplifier Fully Assembled Evaluation Board 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 Rev B4 010417 2-99 RF2131 Absolute Maximum Ratings Parameter Supply Voltage Power Control Voltage (VPC) DC Supply Current Input RF Power Output Load VSWR Operating Case Temperature Ambient Operating Temperature Storage Temperature Rating -0.5 to +8.5 -0.5 to +4.5 570 +12 10:1 -40 to +100 -40 to +85 -40 to +150 Unit VDC V mA dBm °C °C °C 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). 2 POWER AMPLIFIERS Parameter Overall Operating Frequency Range Usable Frequency Range Maximum CW Output Power Total CW Efficiency DC Current at 1.2W Output Input Power for 1.2W output Noise Power Output OFF Isolation Second Harmonic Specification Min. Typ. Max. Unit Condition T=25 °C, VCC =4.8V, VPC set for POUT =+31dBm, Freq=836MHz As configured in Application schematics Depends on output matching At Max Output As configured in Application Circuit #1 In 869 - 894 MHz band (any gain or input power setting) VPC =0V, Input Power=+6dBm Depends upon external matching. Second harmonic levels directly from the IC are approximately 20 to 25dBc +30.5 55 824 to 849 800 to 950 +31 64 400 +6 -90 25 -30 +8 -85 MHz MHz dBm % mA dBm dBm/30kHz dB dBc 20 -25 Input VSWR Input Impedance 20V, so nominally at 4.8V there should be no issue with overvoltage. Under extreme conditions, however, which can occur in a cellular handset environment, the supply voltage could be as high as 7.5V to 8.5V. These conditions may correspond to operation in a battery charger, especially with the battery removed, which "unloads" the supply circuit. To add to this worst-case scenario, the RF drive may be at full power during transmit, and the output VSWR could be extremely high, corresponding to a broken or removed antenna. Under all of the above conditions, the peak RF voltages could well exceed two times the supply voltage, forcing the device into breakdown. The RF2131 includes overvoltage protection diodes at the output, which begin clipping the waveform peaks at approximately 15V. This protects the device’s output from breaking down under these worstRev B4 010417 2 POWER AMPLIFIERS RF2131 case conditions, and provides a rugged, robust component for the system designer. High current conditions are also potentially dangerous to any RF device. High currents lead to high channel temperatures and may force early failures. The RF2131 includes temperature compensation circuits in the bias network to stabilize the RF transistors, thus limiting the current through the amplifier and protecting the devices from damage. The same mechanism works to compensate the currents due to ambient temperature variations. 2 POWER AMPLIFIERS Rev B4 010417 2-103 RF2131 Application Schematic 1 Optimized for Efficiency at 4.8V VCC VPC 10 nF VCC 100 nF 100 pF 2 POWER AMPLIFIERS 1 100 nF 2 10 nF 3 4 5 6 100 pF RF IN VCC 8 100 pF 9 7 10 4.7 pF 14 13 12 11 4.7 pF BIAS 16 15 33 pF 10 nH 2.7 nH 0.200" 100 pF RF OUT 5.6 pF 10 nH 33 pF This schematic defines the optimum configuration for maximum efficiency at 4.8V. Under these conditions, as can be seen in the data plots, the power drops at 4.0V. Over 70% power-added efficiency can be achieved at +30.8dBm with 4.8V and +8dBm input level with this implementation. 2-104 Rev B4 010417 RF2131 Application Schematic 2 Optimized for Power and Efficiency over 4.0V to 4.8V VCC VPC 10 nF VCC 100 nF 100 pF 33 pF 2 POWER AMPLIFIERS RF OUT 6.2 pF 1 100 nF 2 10 nF 3 4 5 6 100 pF RF IN VCC 8 100 pF 7 BIAS 16 10 nH 15 14 13 12 11 10 9 33 pF 4.7 pF 4.7 pF 2.7 nH 0.140" 100 pF 10 nH This application circuit differs from Application schematic 1 only slightly in the output tuning. The output shunt capacitor has been moved 0.060” closer to the device, and has increased from 5.6pF to 6.2pF. This retuning allows over +30.8dBm of output power to be achieved down to 4.0V, however a couple of percent points of efficiency are sacrificed. This implementation is recommended for some additional margin on output power. Rev B4 010417 2-105 RF2131 Evaluation Board Schematic (Download Bill of Materials from www.rfmd.com.) 2 POWER AMPLIFIERS VPC C10 10 nF VCC C12 10 nF R1 0Ω C11 100 nF 1 2 3 4 5 C1 100 pF 6 7 8 C13 100 pF 2131400A C6 33 pF VCC 16 L2 10 nH C3 4.7 pF C8 10 µ F C9 100 pF BIAS 15 14 13 12 11 10 9 C4 4.7 pF L3 10 nH C7 33 pF P1-1 C2 6.2 pF L1 2.7 nH C5 100 pF 50 Ω µ strip RF OUT J2 RF IN J1 VCC 50 Ω µ strip P1 1 2 P1-3 3 VCC GND PC 2-106 Rev B4 010417 RF2131 Evaluation Board Layout 3” x 2” 2 POWER AMPLIFIERS Rev B4 010417 2-107 RF2131 2 POWER AMPLIFIERS 2-108 Rev B4 010417