LT5579

1

5579f

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

1.5GHz to 3.8GHz

High Linearity

Upconverting Mixer

Basestations

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

All other trademarks are the property of their respective owners.

*Operation over wider frequency range is possible with reduced performance.

Consult Linear Technology for information and assistance.

Frequency Upconversion in 2.14GHz W-CDMA Transmitter

Gain, NF and OIP3 vs

RF Output Frequency

× 5mm QFN24 Package

The LT

mixer optimized for frequencies in the 1.5GHz to 3.8GHz

range. The single-ended LO input and RF output ports

simplify board layout and reduce system cost. The mixer

needs only –1dBm of LO power and the balanced design

results in low LO signal leakage to the RF output. At 2.6GHz

operation, the LT5579 provides high conversion gain of

1.3dB, high OIP3 of +26dBm and a low noise floor of

–157.5dBm/Hz at a –5dBm RF output signal level.

The LT5579 offers a high performance alternative to pas-

sive mixers. Unlike passive mixers, which have conversion

loss and require high LO drive levels, the LT5579 delivers

conversion gain at significantly lower LO input levels and

is less sensitive to LO power level variations. The lower

LO drive level requirements, combined with the excellent

LO leakage performance, translate into lower LO signal

contamination of the output signal.

BIAS

LT5579

RF

GND

LO

3.3V

5579 TA01a

1μF

40nH

11Ω

11Ω

33pF

5

4

3

2

1

82pF

MABAES0061

4:1

82pF

100pF

1nF

0.45pF

RF

OUTPUT

LO INPUT

–1dBm (TYP)

IF

INPUT

1.8nH

40nH

RF FREQUENCY (MHz)

1900

0

5

10

15

20

25

OIP3

SSB NF

GAIN

30

2000

2100

2200

2300

5579 TA01b

2400