LT5506 40MHz to 500MHz Quadrature Demodulator with VGA FEATURES DESCRIPTIO n Wide Range 1.8V to 5.25V Supply The LT 5506 is a 40MHz to 500MHz monolithic integrated n Frequency Range: 40MHz to 500MHz quadrature demodulator with variable gain amplifier (VGA), n 4dB to 59dB Variable Power Gain designed for low voltage operation. It supports standards n THD < 0.12% (58dBc) that use a linear modulation format. The chip consists of at 800mV Differential Output Level a VGA, quadrature down-converting mixers and lowpass P-P n 8.8MHz I/Q Lowpass Output Noise Filters noise filters. The LO port consists of a divide-by-two stage n IF Overload Detector and LO buffers. The IC provides all building blocks for IF n Baseband I/Q Amplitude Imbalance: 0.2dB down-conversion to I and Q baseband signals with a single n Baseband I/Q Phase Imbalance: 0.6 supply voltage of 1.8V to 5.25V. The VGA gain has a linear- n 6.8dB Noise Figure at Max Gain in-dB relationship to the control input voltage. Hard-clip- n Input IP3 at Low Gain: 0.5dBm ping amplifiers at the mixer outputs reduce the recovery n Low Supply Current: 27mA time from a signal overload condition. The lowpass filters n Low Delay Shift Over Gain Control Range: 2ps/dB reduce the out-of-band noise and spurious frequency n Outputs Biased Up While in Standby components. The cut-off frequency of the noise filters is n 16-Lead QFN 4mm x 4mm Package with Exposed Pad approximately 8.8MHz. The external 2xLO frequency is required to be twice the IF input frequency for the mixers. U APPLICATIO S The standby mode provides reduced supply current and fast transient response into the normal operating mode n IEEE802.11 when the I/Q outputs are AC-coupled to a baseband chip. n High Speed Wireless LAN , LTC and LT are registered trademarks of Linear Technology Corporation. n Wireless Local Loop TYPICAL APPLICATIO Total Harmonic Distortion vs IF Input Level at 1.8V Supply 1.8V 30 280MHz C2 C1 f = 280MHz IF, 1 IF INPUT + 1F 1nF IF f = 280.1MHz L1 IF, 2 35 f = 570MHz 15nH 2xLO V 800mV DIFFERENTIAL OUT CC P-P C3 + I 10pF OUT 40 L2 IF 15nH I OUT 45 IF DET V CTRL C3 GAIN CONTROL 50 + 1.8pF 2xLO + Q OUT 2xLO C4 55 L3 560MHz 2 3.3pF Q 39nH OUT INPUT 2xLO 60 60 50 40 30 20 10 LT5506 EN STBY GND C5 IF INPUT POWER EACH TONE (dBm) 5506 TA01 3.3pF STANDBY 5506 TA01b ENABLE 5506fa 1 THD (dBc) U ULT5506 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW ORDER PART Supply Voltage ....................................................... 5.5V + NUMBER Differential Voltage Between 2xLO and 2xLO .......... 4V 16 15 14 13 + IF , IF ............................................. 500mV to 500mV GND 1 12 STBY LT5506EUF + + I , I , Q , Q ..................V 1.8V to V + + OUT OUT OUT OUT CC CC IF 2 11 2xLO 17 Operating Ambient Temperature IF 3 10 2xLO (Note 2) ...................................................40 C to 85 C GND 4 9 EN 5 6 7 8 Storage Temperature Range ..................65 C to 125 C Voltage on Any Pin Not to Exceed ........................ 500mV to V + 500mV CC UF PACKAGE 16-LEAD (4mm 4mm) PLASTIC QFN T = 125 C, q = 37 C/W JMAX JA EXPOSED PAD (PIN 17) IS GROUND MUST BE SOLDERED TO PCB Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS V = 3V. f = 570MHz, P = 5dBm (Note 5), f = 284MHz, CC 2xLO 2xLO IF P = 30dBm, I and Q outputs 800mV into 4kW differential load, T = 25 C, EN = V , STBY = V , unless otherwise noted. (Note 3) IF P-P A CC CC SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS IF Input f Frequency Range 40 to 500 MHz IF Nominal Input Level R = 200W Differential 79 to 22 dBm SOURCE + Input Impedance IF , IF to GND, EN = V 100W //1.2pF CC + IF , IF to GND, EN = GND 1pF NF Noise Figure at Max Gain V = 1.7V 6.8 dB CTRL G Min Gain (Note 4) V = 0.2V 0.9 8 dB L CTRL G Max Gain (Note 4) V = 1.7V 50 59 dB H CTRL IIP3 Input IP3, Min Gain P = 22.5dBm (Note 7) 0.5 dBm IF Input IP3, Max Gain P = 75dBm (Note 7) 49 dBm IF IIP2 Input IP2, Max Gain V = 1.7V 8 dBm CTRL Demodulator I/Q Output Nominal Voltage Swing (Note 6) 0.8 V P-P Clipping Level (Note 6) 1.25 V P-P DC Common Mode Voltage V 1.19 V CC I/Q Amplitude Imbalance (Note 8) 0.2 0.5 dB I/Q Phase Imbalance (Note 8) 0.6 3 Deg DC Offset (Notes 6, 8) 28 mV Output Driving Capability Single Ended, C 10pF 2 1.5 kW LOAD STBY to Turn-On Delay 0.3 m s I/Q Output 1dB Compression 11.5 dBm I/Q Output IM3 P = 25.5dBm, 280MHz 50 dBc IF, 1 P = 25.5dBm, 280.1MHz (Note 7) IF, 2 5506fa 2 + V I CC OUT V I CTRL OUT + IF DET Q OUT V Q CC OUT U WWW