Datasheet AD8314 (Analog Devices) - 18

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AD8314 Data Sheet OPERATION AT 2.7 GHz USING THE LFCSP PACKAGE
While the AD8314 is specified to operate at frequencies up to On the underside of the LFCSP package, there is an exposed, 2.5 GHz, it works at higher frequencies, although it does exhibit compressed paddle. This paddle is internally connected to the slightly higher output voltage temperature drift. Figure 43 chip’s ground. While the paddle can be connected to the printed shows the transfer function of a typical device at 2.7 GHz, at circuit board’s ground plane, there is no thermal or electrical ambient as well as hot and cold temperatures. requirement to do this. Figure 44 shows the transfer function of the AD8314 when
EVALUATION BOARD
driven by both an unmodulated sine wave and a 64 QAM Figure 45 shows the schematic of the AD8314  MSOP signal. As previously discussed, the higher peak-to-average ratio evaluation board. The layout and silkscreen of the component of the 64 QAM signal causes an increase in the intercept. side are shown in Figure 46 and Figure 47. An evaluation board In this case, the intercept increases by approximately 1.5 dB, is also available for the LFCSP package. (For exact part numbers, causing the overal transfer function to drop by the same see the Ordering Guide.) Apart from the slightly smaller device amount. For precision operation, the AD8314 should be footprint, the LFCSP evaluation board is identical to the MSOP calibrated for each signal type that is driving it. board. The board is powered by a single supply in the 2.7 V to 5.5 V range. The power supply is decoupled by a single 0.1 µF capacitor. Additional decoupling, in the form of a series resistor or inductor in R9, can also be added. Table 7 details the various configuration options of the evaluation board.
1.2 3 1.2 3 +25°C 1.0 2 1.0 2 CW +25°C –40°C –40°C 0.8 1 0.8 1 ) ) CW ) ) dB dB V V ( ( 0.6 0 R ( 0.6 0 R ( UP UP V V RRO RRO E E 0.4 –1 0.4 –1 64 QAM +80°C +80°C 0.2 –2 0.2 –2 64 QAM 0 –3 0 –3 –70 –60 –50 –40 –30 –20 –10 0 10 –70 –60 –50 –40 –30 –20 –10 0 10
044 043
INPUT POWER (dBm) INPUT POWER (dBm)
01086- 01086- Figure 43. Operating at 2.7 GHz Figure 44. Shift in Transfer Function due to 64 QAM
C1 R2 0.1µF 52.3Ω R1 R9 0Ω 0Ω 1 RFIN VPOS 8 V INPUT POS R3 VPOS 0Ω 2 ENBL V_DN 7 V_DN SW1 AD8314 R4 C2 (OPEN) (OPEN) VSET 3 VSET V_UP 6 R5 4 FLTR COMM 5 0Ω LK1 V_UP C4 (OPEN) R6 C3 (OPEN) (OPEN)
045
R8 R7 OPEN 0Ω
01086- Figure 45. Evaluation Board Schematic Rev. C | Page 18 of 20 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION INVERTED OUTPUT APPLICATIONS BASIC CONNECTIONS TRANSFER FUNCTION IN TERMS OF SLOPE AND INTERCEPT dBV VS. dBm FILTER CAPACITOR OPERATING IN CONTROLLER MODE POWER-ON AND ENABLE GLITCH INPUT COUPLING OPTIONS INCREASING THE LOGARITHMIC SLOPE IN MEASUREMENT MODE EFFECT OF WAVEFORM TYPE ON INTERCEPT MOBILE HANDSET POWER CONTROL EXAMPLES OPERATION AT 2.7 GHz USING THE LFCSP PACKAGE EVALUATION BOARD OUTLINE DIMENSIONS ORDERING GUIDE