lt5538 Linear Technology Corporation, lt5538 Datasheet - Page 7

• Manufacturer Part Number: lt5538
• Description: 40mhz To 3.8ghz Rf Power Detector With 75db Dynamic Range
• Manufacturer: Linear Technology Corporation

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
to V
EN = 3V and 200μA for EN = 5V, respectively. Note that at
no time should the ENBL pin voltage be allowed to exceed
V
IN
V
is connected via internal 394Ω resistor to the IN
should be connected to ground with an ac-decoupling
capacitor.
IN
V
BLOCK DIAGRAM
CC
CC
CC
IN
IN
+
–
+
–
(Pin 3): AC Ground Pin. The pin is internally biased to
–0.5V and coupled to ground via internal 20pF capacitor.
(Pin 2): RF Input Pin. The pin is internally biased to
–0.5V and should be DC blocked externally. The input
CC
by more than 0.3V.
2
3
. Typical enable pin input currents are 100μA for
4
GND
9
RF LIMITER
RF LIMITER
RF LIMITER
DC OFFSET CANCELLATION
–
RF DETECTOR CELLS
pin which
RF LIMITER
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.
V
coupled using 100pF and 0.1μF capacitors.
CAP
These pins are internally connected to the detector outputs
in front of the output buffer amplifi er. An external low-pass
fi ltering can be formed by connecting a capacitor to Vcc
from each pin for fi ltering a low frequency modulation sig-
nal. See the Applications Information section for detail.
OUT (Pin 8): Detector DC Output Pin.
CC
–
(Pin 5): Power Supply Pin. This pin should be de-
, CAP
+
RF LIMITER
(Pins 6, 7): Optional Filter Capacitor Pins.
CAP
6
–
CAP
7
+
LT5538
5538 BD01
5
1
8
V
ENBL
OUT
7
5538f
CC