LT5546 Series

40MHz to 500MHz VGA and I/Q Demodulator with 17MHz Baseband Bandwidth

Catalog

40MHz to 500MHz VGA and I/Q Demodulator with 17MHz Baseband Bandwidth

Part	RF Frequency [Max]	RF Frequency [Min]	Voltage - Supply [Min]	Voltage - Supply [Max]	Supplier Device Package	Package / Case	Function	P1dB	Mounting Type	Noise Figure	Current - Supply	LO Frequency [Min]	LO Frequency [Max]
Analog Devices LT5546EUF#PBF	500 MHz	40 MHz	1.8 V	5.25 V	16-QFN (4x4)	16-WQFN Exposed Pad	Demodulator	-10 dBm	Surface Mount	7.8 dB	24 mA	80 MHz	1 GHz
Analog Devices LT5546EUF#TRPBF	500 MHz	40 MHz	1.8 V	5.25 V	16-QFN (4x4)	16-WQFN Exposed Pad	Demodulator	-10 dBm	Surface Mount	7.8 dB	24 mA	80 MHz	1 GHz

Catalog

40MHz to 500MHz VGA and I/Q Demodulator with 17MHz Baseband Bandwidth

Key Features

• 17MHz I/Q Lowpass Output Noise Filters

• Wide Range 1.8V to 5.25V Supply Voltage

• Frequency Range: 40MHz to 500MHz

• THD < 0.14% (–57dBc) at 800mVP-PDifferential Output Level

• IF Overload Detector

• Log Linear Gain Control Range: –7dB to 56dB

• Baseband I/Q Amplitude Imbalance: 0.2dB

• Baseband I/Q Phase Imbalance: 0.6°

• 7.8dB Noise Figure at Max Gain

• Input IP3 at Low Gain: –1dBm

• Low Supply Current: 24mA

• Low Delay Shift Over Gain Control Range: 2ps/dB

• Outputs Biased Up While in Standby

• 16-Lead QFN 4mm × 4mm Package with Exposed Pad

Description

The LT5546 is a 40MHz to 500MHz monolithic integrated quadrature demodulator with variable gain amplifier (VGA) and 17MHz I/Q baseband bandwidth designed for low voltage operation. It supports standards that use a linear modulation format. The chip consists of a VGA, quadrature down-converting mixers and 17MHz lowpass noise filters (LPF). The LO port consists of a divide-by-two stage and LO buffers. The IC provides all building blocks for IF down-conversion to I and Q baseband signals with a single supply voltage of 1.8V to 5.25V. The VGA gain has a linear-in-dB relationship to the control input voltage. Hard-clipping amplifiers at the mixer outputs reduce the recovery time from a signal overload condition. The lowpass filters reduce the out-of-band noise and spurious frequency components. The –3dB corner frequency of the noise filters is approximately 17MHz and has a first order roll-off. The standby mode provides reduced supply current and fast transient response into the normal operating mode when the I/Q outputs are AC-coupled to a baseband chip.ApplicationsGPS IF ReceiversSatellite IF ReceiversVHF/UHF ReceiversWireless Local Loop