LT5515

1

5515fa

LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

The LT

quadrature demodulator optimized for high linearity re-

ceiver applications. It is suitable for communications

receivers where an RF signal is directly converted into I

and Q baseband signals with bandwidth up to 260MHz.

The LT5515 incorporates balanced I and Q mixers, LO

buffer amplifiers and a precision, high frequency quadra-

ture generator.

In an RF receiver, the high linearity of the LT5515 provides

excellent spur-free dynamic range, even with fixed gain

front end amplification. This direct conversion receiver

can eliminate the need for intermediate frequency (IF)

signal processing, as well as the corresponding require-

ments for image filtering and IF filtering. Channel filtering

can be performed directly at the outputs of the I and Q

channels. These outputs can interface directly to channel-

select filters (LPFs) or to a baseband amplifier.

°

× 4mm Package

with Exposed Pad

1.5GHz to 2.5GHz

Direct Conversion

Quadrature Demodulator

Figure 1. High Signal-Level I/Q Demodulator for Wireless Infrastructure

BPF

5V

BPF

LPF

LT5515

+

–

0

°

LO INPUT

EN

ENABLE

LPF

DSP

+

–

90

°

0

°/90°

5515 F01

LNA

VGA

VGA

I/Q Output Power, IM2, IM3

vs RF Input Power

APPLICATIO S

FEATURES

TYPICAL APPLICATIO

DESCRIPTIO

RF INPUT POWER (dBm)

–16

20

0

–20

–40

–60

–80

–100

–12

–8

–4

0

5515 • TA01

48

IM3

IM2