LT5502 - 400MHz Quadrature IF Demodulator with RSSI

The LT®5502 is a 70MHz to 400MHz monolithic integrated quadrature IF demodulator. It consists of an IF limiter, quadrature down mixers, integrated lowpass filters, and divide-by-two LO buffers. The demodulator provides all building blocks for demodulation of I and Q baseband signals with a single supply voltage of 1.8V to 5.25V. The IF limiter has 84dB small-signal gain, and a built-in receive signal strength indicator (RSSI) with over 90dB linear range. The input referred noise-spectral-density is 1.45nV/√Hz, which is equivalent to a 4dB noise figure when the input is terminated with a 50Ω source. The integrated lowpass output filters act as antialiasing and pulse-shaping filters for demodulated I/Q-baseband signals. The 3dB cutoff frequency of the filters is about 7.7MHz. The VCO frequency is required to be twice the desired operating frequency to provide quadrature local oscillator (LO) signals to the mixers. The standby mode provides fast transient response to the receive mode with reduced supply current when the I/Q outputs are AC-coupled to a baseband chip.

Features
  • Single 1.8V to 5.25V Supply
  • IF Frequency Range: 70MHz to 400MHz
  • 84dB Limiting IF Gain
  • 90dB Linear RSSI Range
  • 7.7MHz Lowpass Output Filter
  • Baseband I/Q Amplitude Imbalance: <0.7dB
  • 4dB Noise Figure
  • Low Supply Current: 25mA
  • Outputs Biased Up While in Standby
  • Shutdown Current: 1mA
  • 24-Lead Narrow SSOP Package
Typical Application
LT5502 Typical Application
LT5502 Typical Application
Applications
  • IEEE802.11
  • High Speed Wireless LAN
  • Wireless Local Loop
Packaging
LT5502 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT5502EGN#PBFSSOP-24E$6.21$5.25
LT5502EGN#TRPBFSSOP-24E$5.35
Demo Boards
Part NumberDescriptionPrice
DC333A-ALT5502EGN | 400MHz IF Receiver with Limiting Amp. and I/Q Demodulator (with IF IContact Factory
DC333A-BLT5502EGN | 400MHz IF Receiver with Limiting Amp. and I/Q Demodulator (with ResiContact Factory
Datasheet
Reliability Data
LT Journal
CAD Symbol
Related Products
LT5502 - 400MHz Quadrature IF Demodulator with RSSI
R409 - Reliability Data
Dec 2002 High Performance 400MHz Quadrature IF Demodulator Runs from 1.8V Supply
LT5502 Footprints and Symbols