1

LT5521

5521f

Very High Linearity

Active Mixer

s

Wideband Output Frequency Range to 3.7GHz

s

+24.2dBm IIP3 at 1.95GHz RF Output

s

Low LO Leakage: –42dBm

s

Integrated LO Buffer: Low LO Drive Level

s

Single-Ended LO Drive

s

Wide Single Supply Range: 3.15V to 5.25V

s

Double-Balanced Active Mixer

s

Shutdown Function

s

16-Lead (4mm

× 4mm) QFN Package

s

Cellular, W-CDMA, PHS and UMTS Infrastructure

s

Cable Downlink Infrastructure

s

Wireless Infrastructure

s

Fixed Wireless Access Equipment

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High Linearity Mixer Applications

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO

PA

2.7nH

LO INPUT

–5dBm

GND

EN

BIAS

110

Ω

LO

2.7nH

4:1

BPF

82pF

6.8pF

1nF

RF

OUTPUT

5V DC

5521 TA01

82pF

6.8pF

1

µF

110

Ω

10pF

1nF

IF

INPUT

1nF

BPF

1:1

Fundamental, 3rd Order

Intermodulation Distortion

vs Input Power

The LT

low distortion and low LO leakage applications. The chip

includes a high speed LO buffer with single-ended input

and a double-balanced active mixer. The LT5521 requires

only –5dBm LO input power to achieve excellent distor-

tion and noise performance, while reducing external drive

circuit requirements. The LO buffer is internally 50

Ω

matched for wideband operation.

With a 250MHz input, a 1.7GHz LO and a 1.95GHz output

frequency, the mixer has a typical IIP3 of +24.2dBm,

–0.5dB conversion gain and a 12.5dB noise figure.

The LT5521 offers exceptional LO-RF isolation, greatly

reducing the need for output filtering to meet LO suppres-

sion requirements.

The device is designed to work over a supply voltage range

from 3.15V to 5.25V.

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

–100

–60

–20

20

–80

–40

0

–10

–6

–2

2

5521 TA02

6

–12

–14

–8

–4

0

4

IM3