 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| RF2138 2 Typical Applications * 3V GSM Cellular Handsets * 3V Dual-Band/Triple-Band Handsets * Commercial and Consumer Systems * Portable Battery-Powered Equipment * GPRS Compatible 3V GSM POWER AMPLIFIER 2 POWER AMPLIFIERS 0.38 0.40 sq. 2.00 1.50 sq. 0.28 0.80 0.13 Tel (336) 664 1233 Fax (336) 664 0454 http://www.rfmd.com Product Description The RF2138 is a high power, high efficiency power amplifier module offering high performance in GSM or GPRS applications. The device is manufactured on an advanced GaAs HBT process, and has been designed for use as the final RF amplifier in GSM hand held-digital cellular equipment and other applications in the 800MHz to 950MHz band. On-board power control provides over 70dB of control range with an analog voltage input, and provides power down with a logic "low" for standby operation. The device is self-contained with 50 input and the output can be easily matched to obtain optimum power and efficiency characteristics. The RF2138 can be used together with the RF2140 for dual-band operation. The device is packaged in an ultra-small ceramic package, minimizing the required board space. Optimum Technology Matching(R) Applied Si BJT Si Bi-CMOS 3.50 3.35 sq. 1 1.50 1.20 ALL SOLDER PAD TOLERANCES P0.05mm ro du ct u GaAs HBT SiGe HBT GaAs MESFET Si CMOS Features * Single 2.7V to 4.8V Supply Voltage * +36dBm Output Power at 3.5V * 32dB Gain with Analog Gain Control * 58% Efficiency * 800MHz to 950MHz Operation * Supports GSM and E-GSM 1 GND2 RF IN GND1 2 3 4 5 16 15 U pg r S ee 6 APC1 7 APC2 ad ed VCC2 VCC2 14 13 12 RF OUT 11 RF OUT 10 RF OUT 9 NC 8 VCC 2F0 NC NC P VCC1 Ordering Information RF2138 RF2138 PCBA 3V GSM Power Amplifier Fully Assembled Evaluation Board Functional Block Diagram RF Micro Devices, Inc. 7628 Thorndike Road Greensboro, NC 27409, USA Rev A9 011031 R F2 17 4.20 sq. 3.95 Package Style: MP16K01A 3 2-119 RF2138 Absolute Maximum Ratings Parameter Supply Voltage Power Control Voltage (VAPC1,2) DC Supply Current Input RF Power Duty Cycle at Max Power Output Load VSWR Operating Case Temperature Storage Temperature Rating -0.5 to +6.0 -0.5 to +3.0 2400 +13 50 10:1 -40 to +85 -55 to +150 Unit VDC V mA dBm % 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 Output Power Specification Min. Typ. Max. Unit Condition Temp=25 C, VCC =3.5V, VAPC1,2 =2.6V, PIN =+6dBm, Freq=880MHz to 915MHz, 25% Duty Cycle, pulse width=1154s See evaluation board schematic. Temp=25 C, VCC =3.5V, VAPC1,2 =2.6V Temp=+25 C, VCC =3.2V, VAPC1,2 =2.6V Temp=+85 C, VCC =3.2V, VAPC1,2 =2.6V Temp=25 C, VCC =2.7V, VAPC1,2 =2.6V Temp=+85 C, VCC =2.7V, VAPC1,2 =2.6V At POUT,MAX, VCC =3.2V At POUT,MAX, VCC =3.0V POUT =+20dBm POUT =+10dBm +34.0 58 58 12 5 +6 Total Efficiency Input Power for Max Output Output Noise Power +4 ro du ct +8 -72 -81 -40 -30 -38 -43 -55 -50 -40 -36 -30 2.5:1 4:1 Forward Isolation Second Harmonic Third Harmonic Fourth Harmonic Fifth Harmonic Sixth Harmonic All Non-Harmonic Spurious ad ed P -45 Input Impedance Optimum Source Impedance Input VSWR Output Load VSWR Output Load Impedance 10:1 S ee U pg r -50 -65 -65 -65 -65 50 40+j10 1.5-j1.7 2-120 R F2 17 dBm dBm dBm dBc dBc dBc dBc dBc dBm dBm +35.0 +34.1 +34.0 +33.0 +32.5 50 880 to 915 800 to 950 +36 +35.2 MHz MHz dBm dBm dBm dBm dBm % % % % dBm dBm RBW=100kHz, 925MHz to 935MHz, POUT,MIN Rev A9 011031 RF2138 Parameter Power Control VAPC1 VAPC2 Power Control "ON" Power Control "OFF" Power Control Range Gain Control Slope APC Input Capacitance APC Input Current Turn On/Off Time 2.6 0.2 75 5 0.5 100 4.5 150 10 5 10 100 V V dB dB/V pF mA A ns V V V A mA A A Maximum POUT, Voltage supplied to the input Minimum POUT, Voltage supplied to the input VAPC1,2 =0.2V to 2.6V POUT =-10dBm to +35dBm DC to 2MHz VAPC1,2 =2.6V VAPC1,2 =0V VAPC1,2 =0 to 2.6V Specifications Nominal operating limits, POUT <+35dBm With maximum output load VSWR 6:1, POUT <+35dBm DC Current at POUT,MAX Idle Current, PIN <-30dBm PIN <-30dBm, VAPC1,2 =0.2V PIN <-30dBm, VAPC1,2 =0.2V, Temp=+85 C Specification Min. Typ. Max. Unit Condition 2 POWER AMPLIFIERS Power Supply Power Supply Voltage 2.7 3.5 4.8 5.5 2 200 1 1 Power Supply Current 50 Rev A9 011031 S ee U pg r ad ed P ro du ct R F2 17 375 10 10 3 2-121 RF2138 Pin 1 2 Function NC GND2 Description Interface Schematic Not connected. Connect this pin to the ground plane for compatibility with future packages. Ground connection for the driver stage. To minimize the noise power at See pin 15. the output, it is recommended to connect this pin with a trace of about 40mil to the ground plane. This will slightly reduce the small signal gain, and lower the noise power. It is important for stability that this pin have it's own vias to the ground plane, minimizing common inductance. RF Input. This is a 50 input, but the actual impedance depends on the interstage matching network connected to pin 5. An external DC blocking capacitor is required if this port is connected to a DC path to ground RF IN or a DC voltage. Ground connection for the pre-amplifier stage. Keep traces physically See pin 3. short and connect immediately to the ground plane for best performance. It is important for stability that this pin has it's own vias to the groundplane, to minimize any common inductance. Power supply for the pre-amplifier stage and interstage matching. This See pin 3. pin forms the shunt inductance needed for proper tuning of the interstage match. Refer to the application schematic for proper configuration. Note that position and value of the components are important. Power Control for the driver stage and pre-amplifier. When this pin is APC "low," all circuits are shut off. A "low" is typically 0.5V or less at room temperature. A shunt bypass capacitor is required. During normal operation this pin is the power control. Control range varies from about 1.0V for -10dBm to 2.6V for +35dBm RF output power. The maximum power that can be achieved depends on the actual output matching; see the application information for more details. The maximum current into this pin is 5mA when VAPC1 =2.6V, and 0mA when VAPC =0V. 2 POWER AMPLIFIERS 3 RF IN VCC1 From Bias GND1 Stages 4 GND1 5 VCC1 3 6 APC1 VCC R F2 17 To RF Stages GND GND 7 8 9 10 APC2 VCC NC RF OUT Power Control for the output stage. See pin 6 for more details. Power supply for the bias circuits. ro du ct See pin 6. See pin 6. P Not connected. Connect this pin to the ground plane for compatibility with future packages. RF Output and power supply for the output stage. Bias voltage for the final stage is provided through this wide output pin. An external matching network is required to provide the optimum load impedance. RF OUT S ee 14 15 NC VCC2 U pg r 11 12 13 RF OUT RF OUT 2F0 Same as pin 10. Same as pin 10. ad ed From Bias GND Stages PCKG BASE Same as pin 10. Same as pin 10. Same as pin 10. Connection for the second harmonic trap. This pin is internally connected to the RF OUT pins. The bonding wire together with an external capacitor form a series resonator that should be tuned to the second harmonic frequency in order to increase efficiency and reduce spurious outputs. Not connected. Power supply for the driver stage and interstage matching. This pin forms the shunt inductance needed for proper tuning of the interstage match. Please refer to the application schematic for proper configuration, and note that position and value of the components are important. Same as pin 15. Ground connection for the output stage. This pad should be connected to the ground plane by vias directly under the device. A short path is required to obtain optimum performance, as well as to provide a good thermal path to the PCB for maximum heat dissipation. VCC2 From Bias GND2 Stages 16 Pkg Base VCC2 GND Same as pin 15. 2-122 Rev A9 011031 RF2138 Theory of Operation and Application Information The RF2138 is a three-stage device with 32 dB gain at full power. Therefore, the drive required to fully saturate the output is +3dBm. Based upon HBT (Heterojunction Bipolar Transistor) technology, the part requires only a single positive 3V supply to operate to full specification. Power control is provided through a single pin interface, with a separate Power Down control pin. The final stage ground is achieved through the large pad in the middle of the backside of the package. First and second stage grounds are brought out through separate ground pins for isolation from the output. These grounds should be connected directly with vias to the PCB ground plane, and not connected with the output ground to form a so called "local ground plane" on the top layer of the PCB. The output is brought out through the wide output pad, and forms the RF output signal path. The amplifier operates in near Class C bias mode. The final stage is "deep AB", meaning the quiescent current is very low. As the RF drive is increased, the final stage self-biases, causing the bias point to shift up and, at full power, draws about 2000mA. The optimum load for the output stage is approximately 1.2. This is the load at the output collector, and is created by the series inductance formed by the output bond wires, vias, and microstrip, and 2 shunt capacitors external to the part. The optimum load impedance at the RF Output pad is 1.2-j1.7. With this match, a 50 terminal impedance is achieved. The input is internally matched to 50 with just a blocking capacitor needed. This data sheet defines the configuration for GSM operation. The input is DC coupled; thus, a blocking cap must be inserted in series. Also, the first stage bias may be adjusted by a resistive divider with high value resistors on this pin to VPC and ground. For nominal operation, however, no external adjustment is necessary as internal resistors set the bias point optimally. VCC1 and VCC2 provide supply voltage to the first and second stage, as well as provides some frequency selectivity to tune to the operating band. Essentially, the bias is fed to this pin through a short microstrip. A bypass capacitor sets the inductance seen by the part, so placement of the bypass cap can affect the frequency of the gain peak. This supply should be bypassed individually with 100pF capacitors before being combined with VCC for the output stage to prevent feedback and oscillations. The RF OUT pin provides the output power. Bias for the final stage is fed to this output line, and the feed must be capable of supporting the approximately 2A of current required. Care should be taken to keep the losses low in the bias feed and output components. A narrow microstrip line is recommended because DC losses in a bias choke will degrade efficiency and power. While the part is safe under CW operation, maximum power and reliability will be achieved under pulsed conditions. The data shown in this data sheet is based on a 12.5% duty cycle and a 600s pulse, unless specified otherwise. The part will operate over a 3.0V to 5.0V range. Under nominal conditions, the power at 3.5V will be greater than +34.5dBm at +90C. As the voltage is increased, however, the output power will increase. Thus, in a system design, the ALC (Automatic Level Control) Loop will back down the power to the desired level. This must occur during operation, or the device may be damaged from too much power dissipation. At 5.0V, over +38dBm may be produced; however, this level of power is not recommended, and can cause damage to the device. The HBT breakdown voltage is >20V, so there are no issue with overvoltage. However, under worst-case conditions, with the RF drive at full power during transmit, and the output VSWR extremely high, a low load impedance at the collector of the output transistors can cause currents much higher than normal. Due to the bipolar nature of the devices, there is no limitation on the amount of current de device will sink, and the safe current densities could be exceeded. High current conditions are potentially dangerous to any RF device. High currents lead to high channel temperatures and may force early failures. The RF2138 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. To avoid excessively high currents it is important to control the VAPC when operating at supply voltages higher than 4.0V, such that the maximum output power is not exceeded. 2 POWER AMPLIFIERS Rev A9 011031 S ee U pg r ad ed P ro du ct R F2 17 3 2-123 RF2138 Application Schematic VCC 1 nF 120 pF Very close to pins 15/16 Instead of a stripline an inductor of ~10 nH can be used 2 POWER AMPLIFIERS 1 .040" 2 RF IN 180 1 nF 4 5 6 7 8 10 9 3 12 11 16 15 14 13 4.3 pF VCC Instead of a stripline an inductor of 4.7 nH can be used Quarter Wave Length 50 strip 18 pF 33 pF 33 pF RF OUT 5.6 pF VCC 10 nH 33 pF 33 pF 33 pF 33 pF Note: All capacitors are standard 0402 multi layer Internal Schematic 5 ad ed 4.5 pF P VCC1 ro du ct APC R F2 17 VCC2 RF OUT APC2 VCC 300 GND2 PKG BASE RF IN U pg r APC1 VCC 1.6k APC1 5 1k 2-124 S ee GND1 3 Rev A9 011031 VCC Spacing between edge of device and capacitor 0.062" Distance center to center of capacitors 0.416" RF2138 Evaluation Board Schematic (Download Bill of Materials from www.rfmd.com.) P1 C20 3.3 uF + C7 1 nF C24 120 pF VCC1 C19 3.3 uF + C6 1 nF C12 33 pF L2 8.8 nH C21 9.1 pF C13 33 pF C23 5.6 pF 1 2 3 4 5 6 CON3 GND VCC1 VCC1 GND VCC1 2 POWER AMPLIFIERS 50 strip J2 RF OUT 1 2 3 R1 180 4 5 L1 10 nH C8 33 pF C2 1 nF VCC1 + C17 3.3 uF 16 15 14 13 12 11 J1 RF IN 50 strip C1 1 nF 50 strip C22 11 pF 6 7 8 9 C14 10 nF C3 1 nF C9 33 pF C10 33 pF C4 1 nF C11 33 pF J3 VPC ro du ct R F2 17 C5 1 nF C16 10 nF VCC1 + C18 3.3 uF 2138400 Rev A C15 10 nF Rev A9 011031 S ee U pg r ad ed P 3 10 2-125 RF2138 Evaluation Board Layout Board size 2.0" x 2.0" Board Thickness 0.014"; Board Material FR-4; Multi-Layer 2 POWER AMPLIFIERS 2-126 S ee U pg r ad ed P ro du ct R F2 17 Rev A9 011031 3 RF2138 Typical Test Setup Power Supply V- S- S+ V+ 2 POWER AMPLIFIERS RF Generator 3dB Buffer x1 OpAmp Puls Generator A buffer amplifier is recommended because the current into the Vapc changes with voltage. As an alternative, the voltage may be monitored with an oscilloscope. Notes about testing the RF2138 The test setup shown above includes two attenuators. The 3dB pad at the input is to minimize the effects that the switching of the input impedance of the PA has on the signal generator. When Vapc is switched quickly, the resulting input impedance change can cause the signal generator to vary its output signal, either in output level or in frequency. Instead of an attenuator an isolator may also be used. The attenuator at the output is to prevent damage to the spectrum analyzer, and should be able to handle the power. It is important not to exceed the rated supply current and output power. When testing the device at higher than nominal supply voltage, the VAPC should be adjusted to avoid the output power exceeding +36dBm. During load-pull testing at the output it is important to monitor the forward power through a directional coupler. The forward power should not exceed +36dBm, and VAPC needs to be adjusted accordingly. This simulates the behavior for the power control loop in this respect. To avoid damage, it is recommended to set the power supply to limiting the current during the burst, not to exceed the maximum current rating. Rev A9 011031 S ee U pg r ad ed P ro du ct R F2 17 10dB/5W 3 Spectrum Analyzer 2-127 2 POWER AMPLIFIERS 2-128 RF2138 S ee U pg r ad ed P ro du ct R F2 17 3 Rev A9 011031 |
Price & Availability of RF2138PCBA
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |