link to page 9 link to page 9 link to page 9 ADL557064 QAM OFDMA PERFORMANCE0.9 The ADL5570 shows exceptional performance when used with 0.8 a higher order modulation scheme, such as a 64 QAM system. 0.7 Figure 13, Figure 14, and Figure 15 illuminate the EVM, gain, 0.6 and current consumption performance within the context of ) A ( a 64 QAM OFDMA system. 0.5NT E190.418CURR170.316 152350MHz0.214 130.112)112400MHz01005101520253035 08 0 M (%9 9- 72 EVP8OUT (dBm) 06 7 Figure 15. Burst Current vs. POUT at VCC = 3.5 V, 64 QAM, 6 2350 MHz, 31% 802.16e OFDMA Signal 5 4 32300MHzPOWER-ADDED EFFICIENCY2 1 The efficiency of the ADL5570 is defined on the current that it 0 draws during the data burst of an 802.16e OFDMA signal. In 06 05101520253035 0 9- 72 POUT (dBm) typical test setup, the average rms current, IAVG, is measured. 06 Figure 13. EVM vs. P However, OUT Performance at VCC = 3.5 V and 64 QAM OFDMA Signal IAVG = Duty Cycle (in decimal) × IBURST + 32 (1 − Duty Cycle [in decimal]) × IDEFAULT where: I 31 BURST is the rms current during the data burst of an OFDMA signal. ) IDEFAULT can be the quiescent current drawn when there is no B d (30 data burst and the device remains biased, the sleep current IN (1 mA) if the device is defaulted to sleep mode, or the GA standby current. 29 For example, in a 31% duty cycle 802.16e OFDMA signal, the burst current is calculated by rearranging the previous equation to get 2822802300232023402360238024002420 7 (Ι − 0.69× I ) -00 AVG DEFAULT = 29 I FREQUENCY (MHz) 67 BURST 0 0.31 Figure 14. Gain vs. Frequency Performance at V Finally, the PAE is calculated by CC = 3.5 V and 64 QAM OFDMA Signal RF Output Power (mW) − RF Input Power (mW) PAE (%) = × 100 V (V) × I (mA) CC BURST When RF = 2.35 GHz, 31% 16 QAM OFDMA signal, VCC = 3.5 V, RF output power = 25 dBm, and RF input power = −4 dBm, the ADL5570 consumes a burst current, IBURST = 450 mA and PAE = 21%. Rev. 0 | Page 9 of 12 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS VCC = 3.5 V ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS APPLICATIONS BASIC CONNECTIONS Power Supply RF Input Interface RF Output Interface Transmit/Standby Enable VREG Enable MODE High Power/Low Power Enable 64 QAM OFDMA PERFORMANCE POWER-ADDED EFFICIENCY EVALUATION BOARD MEASUREMENT SETUP USING THE ADL5570 EVALUATION BOARD OUTLINE DIMENSIONS ORDERING GUIDE