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Demo board DC333A Quick Start Guide.

Introduction

Demo board DC333A demonstrates operation of the LT5502 IC. The LT5502 is a high

performance limiting amplifier and quadrature IF demodulator with 70MHz to 400MHz

input frequency, operating over the wide supply voltage range, from 5.25V down to 1.8V.

This allows the LT5502 to run directly from a single Lithium Ion battery, or from two or

more NiCad batteries. In combination with an appropriate RF front end and RF/IF bandpass

filters, the LT5502 forms a wideband receiver for applications at 900MHz, 1.8GHz, 2.4-

2.5GHz, or other frequencies. The LT5502 can even be used as a self-standing receiver at

frequencies below 400MHz.

Figure 1. Demo board DC333A block diagram.

LT5502

1

2

Buffer

I mixer

f/2

0º

90º

LPF

Limiter 1

Buffer

LPF

RSSI

output

STBY

Limiter 2

Vcc

+2.0 to 5.0 V

62 ohm

1.8 pF

100 pF

0.1 uF

IF Input

I outputs

Q outputs

24

23

11

10

3, 5, 8, 9,

14, 20, 21

15

Q mixer

4, 16, 17, 22

12

13

18

19

LO

buffer

6

7

EN

2d LO input

External

Buffer

Q output

External

Buffer

I output