LT5578

1

5578f

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

0.4GHz to 2.7GHz

High Linearity

Upconverting Mixer

Frequency Upconversion in LTE Transmitter

Gain, NF and OIP3 vs

RF Output Frequency

24.3dBm at 1.95GHz

× 5mm QFN24 Package

(Pin Compatible with LT5579)

The LT

mixer optimized for frequencies in the 0.4GHz to 2.7GHz

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

1.95GHz operation, the LT5578 provides conversion gain

of –0.7dB, high OIP3 of 24.3dBm and a low noise floor of

–158dBm/Hz at a –5dBm RF output signal level.

The LT5578 offers a high performance alternative to pas-

sive mixers. Unlike passive mixers, which have conversion

loss and require high LO drive levels, the LT5578 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.

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

BIAS

LT5578

RF

GND

LO

3.3V

5579 TA01a

10μF

100nH

13.7Ω

13.7Ω

39pF

220pF

TC4-1W+

4:1

220pF

6.8pF

2.7pF

100μF

1nF

2pF

RF

700MHz

TO 950MHz

LO INPUT

–1dBm

IF

140MHz

22nH

2.7pF

13nH

100nH

RF OUTPUT FREQUENCY (MHz)

650

20

25

30

OIP3

800

900

5578 TA01b

15

10

700

750

850

950

1000

5

0

SSB NF

GAIN