LT5517 40MHz to 900MHz Quadrature Demodulator FEATURES DESCRIPTIO n RF Input Frequency Range: 40MHz to 900MHz The LT 5517 is a 40MHz to 900MHz quadrature demodu- n High IIP3: 21dBm at 800MHz lator optimized for high linearity receiver applications n High IIP2: 58dBm at 800MHz where high dynamic range is important. It is suitable for n I/Q Gain Mismatch: 0.3dB Max communications receivers where an RF or IF signal is n I/Q Phase Mismatch: 0.7 directly converted into I and Q baseband signals with a n Noise Figure: 12.4dB at 800MHz bandwidth up to 130MHz. The LT5517 incorporates bal- n Conversion Gain: 3.3dB at 800MHz anced I and Q mixers, LO buffer amplifiers and a precision, n Baseband Bandwidth: 130MHz broadband quadrature generator derived from an on-chip n Single Ended, 50W Matched 2XLO Input divide-by-two circuit. n Shutdown Mode The superior linearity and low noise performance of the n 16-Lead QFN (4mm 4mm) Package LT5517 is achieved across its full frequency range. A well- with Exposed Pad balanced divide-by-two circuit generates precision quadra- ture LO carriers to drive the I mixer and the Q mixer. U Consequently, the outputs of the I-channel and the APPLICATIO S Q-channel are well matched in amplitude, and their phases n Wireless Infrastructure are 90 apart. The LT5517 also provides excellent 50W n High Linearity Direct Conversion I/Q Receiver impedance matching at the 2XLO port across its entire n High Linearity I/Q Demodulator frequency range. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO I/Q Output Power, IM3, IM2 5V vs RF Input Power BPF BPF 20 V + LT5517 CC RF LNA + LPF I OUT 0 VGA P OUT I OUT 20 0 T = 25C A RF P = 10dBm 2XLO 40 f = 1602MHz 2XLO DSP IM3 f = 799.9MHz RF1 f = 800.1MHz RF2 60 + LPF Q OUT IM2 2xLO 2xLO 2 VGA INPUT 80 Q OUT 90 ENABLE EN 5517 F01 100 18 14 10 6 2 2 RF INPUT POWER (dBm) Figure 1. High Signal-Level I/Q Demodulator for 450MHz Infrastructure Receiver 5517 F01b 5517f 1 P , IM3, IM2 (dBm/TONE) OUT U ULT5517 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART TOP VIEW Power Supply Voltage ............................................ 5.5V NUMBER Enable Voltage ....................................................0V, V CC 16 15 14 13 2XLO Voltage (10dBm Equivalent) .......................... 1V LT5517EUF + GNDRF 1 12 V CC RF to RF Differential Voltage + RF 2 11 GND (10dBm Equivalent) ................................................. 2V 17 RF 3 10 2XLO Operating Ambient Temperature ..............40 C to 85 C GNDRF 4 9 GND Storage Temperature Range ................. 65 C to 125 C UF PART 5 6 7 8 Maximum Junction Temperature .......................... 125 C MARKING UF PACKAGE 16-LEAD (4mm 4mm) PLASTIC QFN 5517 EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB T = 125 C, q = 37 C/W JMAX JA Consult LTC Marketing for parts specified with wider operating temperature ranges. AC ELECTRICAL CHARACTERISTICS T = 25 C. V = 5V, EN = V , f = 799.9MHz, f = 800.1MHz, A CC CC RF1 RF2 f = 1602MHz, P = 10dBm, unless otherwise noted. (Notes 2, 3) (Test circuit shown in Figure 2) 2XLO 2XLO PARAMETER CONDITIONS MIN TYP MAX UNITS RF Frequency Range 40 to 900 MHz 2XLO Frequency Range 80 to 1800 MHz 2XLO Power 15 to 0 dBm 2XLO Port Return Loss Internally Matched to a 50W Source 20 dB Conversion Gain Voltage Gain, Load Impedance = 1kW 0 3.3 dB Gain Variation vs Temperature 40 C to 85 C 0.01 dB/ C Noise Figure 12.4 dB Input 3rd Order Intercept 2-Tone, 10dBm/Tone, D f = 200kHz 21 dBm Input 2nd Order Intercept 2-Tone, 10dBm/Tone, D f = 200kHz 58 dBm Input 1dB Compression 10 dBm Baseband Bandwidth 130 MHz I/Q Gain Mismatch (Note 4) 0.3 0.03 0.3 dB I/Q Phase Mismatch (Note 4) 3.5 0.7 3.5 deg Output Impedance Differential 120 W 2XLO to RF Leakage 69 dBm LO to RF Leakage 80 dBm RF to 2XLO Isolation 63 dB 5517f 2 + EN I OUT V I CC OUT + V Q CC OUT V Q CC OUT U WWW