LT5538

7

5538f

PIN FUNCTIONS

ENBL (Pin 1): Enable Pin. An applied voltage above 1V will

activate the bias for the IC. For an applied voltage below

0.3V, the circuits will be shut down (disabled) with a cor-

responding reduction in power supply current. If the enable

function is not required, then this pin can be connected

EN = 3V and 200μA for EN = 5V, respectively. Note that at

no time should the ENBL pin voltage be allowed to exceed

RF Input Pin. The pin is internally biased to

should be connected to ground with an ac-decoupling

capacitor.

AC Ground Pin. The pin is internally biased to

This pin should be connected to ground with an external

ac-decoupling capacitor for low frequency operation.

GND (Pin 4, Exposed Pad Pin 9): Circuit Ground Return

for the entire IC. This pin must be soldered to the printed

circuit board ground plane.

coupled using 100pF and 0.1μF capacitors.

Optional Filter Capacitor Pins.

These pins are internally connected to the detector outputs

in front of the output buffer amplifier. An external low-pass

filtering can be formed by connecting a capacitor to Vcc

from each pin for filtering a low frequency modulation sig-

nal. See the Applications Information section for detail.

OUT (Pin 8): Detector DC Output Pin.

BLOCK DIAGRAM

RF LIMITER

GND

RF LIMITER

RF DETECTOR CELLS

DC OFFSET CANCELLATION

RF LIMITER

RF LIMITER

RF LIMITER

3

2

4

9

7

6

OUT

8

ENBL

1

5

5538 BD01