LT5520

1

5520f

APPLICATIO S

FEATURES

DESCRIPTIO

TYPICAL APPLICATIO

s

Wide RF Output Frequency Range: 1.3GHz

to 2.3GHz

s

15.9dBm Typical Input IP3 at 1.9GHz

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On-Chip RF Output Transformer

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No External LO or RF Matching Required

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Single-Ended LO and RF Operation

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Integrated LO Buffer: –5dBm Drive Level

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Low LO to RF Leakage: – 41dBm Typical

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Wide IF Frequency Range: DC to 400MHz

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Enable Function with Low Off-State Leakage Current

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Single 5V Supply

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Small 16-Lead QFN Plastic Package

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Wireless Infrastructure

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Cable Downlink Infrastructure

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Point-to-Point Data Communications

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High Linearity Frequency Conversion

1.3GHz to 2.3GHz

High Linearity

Upconverting Mixer

The LT

requirements of wireless and cable infrastructure trans-

mission applications. A high-speed, internally matched,

LO amplifier drives a double-balanced mixer core, allow-

ing the use of a low power, single-ended LO source. An RF

output transformer is integrated, thus eliminating the

need for external matching components at the RF output,

while reducing system cost, component count, board area

and system-level variations. The IF port can be easily

matched to a broad range of frequencies for use in many

different applications.

The LT5520 mixer delivers 15.9dBm typical input 3rd

order intercept point at 1.9GHz with IF input signal levels

of –10dBm. The input 1dB compression point is typically

4dBm. The IC requires only a single 5V supply.

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

Figure 1. Frequency Conversion in Wireless Infrastructure Transmitter

RF Output Power and Output IM3 vs

IF Input Power (Two Input Tones)

PA

LO INPUT

–5dBm

BIAS

EN

5520 F01

BPF

BPF

GND

IF

INPUT

4:1

220pF

220pF

15pF

100

Ω

100

Ω

(OPTIONAL)

1

µF

1000pF

39nH

RF

OUTPUT

10pF

5pF

5pF

85

Ω

LT5520

IF INPUT POWER (dBm/TONE)

–16

10

0

–10

–20

–30

–40

–50

–60

–70

–80

–90

0

5520 • F01b

–12

–8

–4

4

IM3