LTC5535

9

5535f

APPLICATIO S I FOR ATIO

Operation

The LTC5535 RF detector integrates several functions to

provide RF power detection over frequencies ranging

from 600MHz to 7GHz. These functions include an internal

frequency compensated output amplifier, an RF Schottky

diode peak detector and a level shift amplifier to convert the

RF input signal to DC. The LTC5535 has both gain setting

and voltage offset adjustment capabilities.

Output Amplifier

The output amplifier is capable of supplying typically

to a pin for gain selection. External resistors connected

the gain of this amplifier.

The amplifier is not unity gain stable; a minimum gain of

two is required. The output amplifier has a bandwidth of

20MHz with a gain of 2. For increased gain applications,

the bandwidth is reduced according to the formula:

For stable operation the gain setting resistors should be

500Ω for all gain settings.

output voltage is not to be changed. The output amplifier

nected to ground.

voltage. This function, in combination with gain adjust-

ment enables the LTC5535 output to span the input range

where gain is the output amplifier gain. For a gain of 2,

RF Detector

The internal RF Schottky diode peak detector and level

shift amplifier converts the RF input signal to a low

frequency signal. The detector demonstrates excellent

efficiency and linearity over a wide range of input power.

The Schottky diode is biased at about 50µA and drives a

5pF internal peak detector capacitor.

GND

LTC5535ES6

1

2

3

6

5

4

C4

39pF

R1

(OPT)

OFFSET

ADJUSTMENT

C2

100pF

C1

0.1µF

(OPT)

2.7V TO 5.5V

GND

R2

500Ω

1%

R3

500Ω

1%

5535 DB

Demo Board Schematic