1

LT5500

5500f

TYPICAL APPLICATIO

FEATURES

DESCRIPTIO

APPLICATIO S

1.8GHz to 2.7GHz

Receiver Front End

The LT

voltage operation. The chip contains a low noise amplifier

(LNA), a Mixer and an LO buffer. The IC is designed to

operate over a power supply voltage range from 1.8V to

5.25V.

The LNA can be set to either high gain or low gain mode.

At 2.5GHz, the high gain mode provides 13.5dB gain and

a noise figure (NF) of 4dB. The LNA in low gain mode

provides –14dB gain and an IIP3 of + 8dBm at 2.5GHz.

The mixer has 5dB of conversion gain and an IIP3 of

– 2.5dBm at 2.5GHz, with –10dBm LO input power.

Figure 1. 2.5GHz Receiver. Interstage Filter is Optional

LO

MIX_IN

LNA_OUT

LNA_IN

LNA_GND

GND

GS

EN

LT5500

MIX_GND

2V

5500 F01

2V

••

T2

8:1

IF

RF

C4

C17

C23

L3

L5

L7

IF OUTPUT

RF

INPUT

L4

100pF

×2

L2

2V

GAIN

SELECT

RF INPUT

FILTER

ENABLE

100pF

100pF

L9

LO INPUT

INTERSTAGE

FILTER

100pF

×4

1nF

100pF

1µF

LNA Gain (High Gain Mode)

and Mixer Conversion Gain

1.5

13.4

13.6

13.7

5.5

5500 TA02

13.2

13.0

2.5

3.5

4.5

2

3

4

5

14.0

13.3

13.5

13.1

13.8

13.9

4.8

5.2

5.4

4.4

4.0

6.0

4.6

5.0

4.2

5.6

5.8

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

All other trademarks are the property of their respective owners.