WIRELESS ~ Power Amplifier AWTO0908 TX POWER MMIC Advanced Product Information Rev 0 900 MHz Band GSM GaAs Power Amplifier IC DESCRIPTION The AWT0908X is a monolithic Power Amplifier IC suited for GSM cellular telephone Applications FEATURES High Output Power High Efficiency Single Supply Low Harmonics Built in Pulse Shaping Small Size Surface Mount Package 50Q Input Impedance Low Cost | T] g | Tt] | Te] 1. Maximum Ratings Static sensitive electronic devices. Do not operate or store near strong electrostatic, fields. Take proper ESD precautions. Pin Rating Notes Pin 2 - RF + 12 dBm max., Pin 3 - Vrer + 5V max., 0 V min. If Vper is kept high and not pulsed, the amplifier may draw very high currents and permanent damage may occur. Pin 4 - VdB +7.5V max., 0 V min. Pin 5 - Vssin N/A Do not apply voltage to this pin. If Vssm is not between - 4V and - 4.5V (with Voen = 4.8V), the amplifier may not work properly. 195 WIRELESS Power Amplifier AWT0908 Pin Rating Notes Pin 10 VssOUT N/A Do not apply voltage to these pin Pin 11, Pin 12 N/A Do not apply voltage to these pins. Pin 13 - Voen +7.5 V max. 0 V min. Voen must be turned on before any of the drain supplies. Pin 16 - D2 +7.5 V max.,0 V min. Pinl9 - D3B +7.5 V max,,0 V min. Pin 24- D3A +7.5 V max.,0 V min. Pin 27-D1 +7.5 V max.,0 V min. 2. ELECTRICAL CHARACTERISTICS: (Pin <+7 dBm, Vps = + 4.8Vpc, Varn = + 4.8 Voc, Pulsed @ 577 uS/12.5% Duty Cycle, Te= 25C, 50Q Input & 50Q external output match) PARAMETER SYMBOL MIN. | TYP. | MAX. PARAMETER Frequency fo 880 915 MHz Power Output Pout 35 dBm @ VREF < 3.7 Vv Power Added Efficiency PAE 50 % Harmonics (@ 35 dBm) 2fo - 38 dBe 3rd -28 Stability: - 80 dBc, VSWR load, all phase angles, all spurious outputs relative to 6:1 (Pour <= 35dBm) desired signal Vos = +4.8.0V, Zs = 50Q Input Return Loss Rim 12 dB Isolation - 40 dBm DC/DC Converter Current Igen 5.5 mA Pulse Control Ter 2 mA Operating Range Te - 20 +70 C 196 WIRELESS ~ Power Amplifier AWT0908 3. DATA AWTO0908 Pout and Efficiency as functions of T 56% Da a 4 - |- 10; o Efficiency 49% >~oo ~| 42% | | 35% + 28% /=902.4MHz 21% Vdd=4.8V Pin=+5.0dBm 14% VREF pulsed at 12.5% duty cycle 7% \ Pulse width - 577uS y - F ; 0% 15 2 2.5 3 3.5 4 45 5 Power Control Voltage - VREF [V] Pout ~~ wut -=- Efficienc 4. Case Outline and Pin Description ia 39040.004 . 0.008 ~s) Ly | 4 . 1 0.240 x | Tre 197 WIRELESS ~ Power Amplifier AWT0908 Pin Signal Description I GND RF and DC Ground 2 RFin RF power input, DC blocked 3 Varer Output Power control, Should be set to level that corresponds to the desired output power Pulse control voltage (Veer, 0 to 4 V) 4 Vpp Bias circuit Supply (+ 4.8 V, 5 ma ) 5 Vss In Negative Supply (-4.5V) generated by the dce/de converter 6,7,8,9 GND RF and DC Ground (The Batwing) _ 10 Vss gut The output of the dc/de converter providing the negative voltage 11,12 Pump capacitor (C5) which is part of the de/dc converter circuit. 13 Voen DC/DC converter positive supply AC and DC ground for the de/de converter .If possible should be 14 GND grounded through a separate via hole . 15 GND RF and DC ground. 16 Vp2 The open drain of the second amplifier stage 17 GND RF and DC Ground 18 N/C Not Connected 19 Vo 3rd stage drain supply (4.8V) and RF out 20,21,22,23 GND RF and DC ground (the BATWING) 24 Vp3a 3rd stage drain supply (4.8V) and RF out 25 N/C Not Connected 26 GND RF and DC ground 27 Voi Ist stage drain supply (4.8V) _ 28 GND RF and DC Ground 5, Recommended Operating Procedure on the Evaluation Board Power Up A. Begin by setting all power supplies to zero volts. B. Make sure that the input RF power is turned off. C. Turn on Veen (Pin 13) to + 4.8V D. Check the voltage @ Vss_in (pin 5) to see if it is between -4.5 V and - 4.0V if voltage is not ,check the pin alignment. E. Turn on Vp;(Pin 27), Vo2(Pin 16), Vp3(Pins 19 and 24) and Vpg (Pin 4) which are tied together on the Qm fixture, and set to + 4.8V. Little drain current should be flowing at this time (Ipp < 5 mA). Turn RF on and adjust input power to 5 dBm. Turn Veer on using the pulsed scheme of GSM. Adjust Pulse Veer to desired output power (< = 35 dBm). No lower than 0 V and no higher than +3.7 V. Use an oscilloscope to measure Vrer on the Vrer package pin (3) rather than using the display of the pulse generator. The reason for that is that the pulse generator may have a 50 output impedance while the impedance of Veer pin is high. This causes the voltage on Vrer pin to be almost twice as high as the readout on the pulse generator. Power Down To power down the device follow the above procedure in reverse order . 198 WIRELESS - Power Amplifier AWT0908 6. AWT0908 TEST CIRCUIT eos ah hb b -) COMPONENTS 1, Turn Veen on first (+4.8V) 2. Apply + 4.8 V to VD1, VD2, VDB 3. Apply +4.8 V to Vo, C7,C10,C11 4. Pulse Ves between 0 V and 3.7 V CBA 199