LT5546 - 40MHz to 500MHz VGA and I/Q Demodulator with 17MHz Baseband Bandwidth

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 downconverting 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 rolloff.  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.

  • 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-P Differential 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
Typical Application
LT5546 Typical Application
LT5546 Typical Application
  • GPS IF Receivers
  • Satellite IF Receivers
  • VHF/UHF Receivers
  • Wireless Local Loop
LT5546 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT5546EUF#PBF4x4 QFN-16E$4.73$3.35
LT5546EUF#TRPBF4x4 QFN-16E$3.45
Demo Boards
Part NumberDescriptionPrice
DC696ALT5546EUF | 500MHz IF Receiver w/ VGA and I/Q Demodulator and Wide BB BW$125.00
Reliability Data
CAD Symbol
Related Products
LT5546 - 40MHz to 500MHz VGA and I/Q Demodulator with 17MHz Baseband Bandwidth
R409 - Reliability Data
LT5546 Footprints and Symbols