
LTC5583
14
5583fa
PIN FUNCTIONS
DECA, DECB (Pins 1, 6): Input Common Mode Decou-
pling Pins for Channel A and Channel B. These pins are
internally biased to 1.6V. The input impedance is 1.75k
in parallel with a 40pF internal shunt capacitor to ground.
The impedance between DECA and IN+A (or IN–A) is 200.
The pin can be connected to the center tap of an external
balun or to a capacitor to ground.
VCCA, VCCB, VCCR (Pins 2, 5, 3): Power Supply Pins for
Channel A, Channel B, and Bias Circuits. Typical total cur-
rent consumption of these pins is 81mA. Each of these
pins should be bypassed with 1nF and 1µF capacitors,
placed as close to the IC as possible.
EN (Pin 4): Enable Input Pin. An applied voltage above
2V will activate the bias for the IC. For an applied voltage
below 0.3V, the circuit will be shut down (disabled) with
a corresponding reduction in power supply current. If
the enable function is not required, then this pin can be
connected to VCC. The applied voltage to this pin should
not exceed VCC by more than 0.3V.
RP2 (Pin 9): Pin for Setting Polarity of Second Order Output
Temperature Compensation. Connect this pin to ground
to change the output voltage inversely proportional to
ambient temperature. Float this pin to change the output
voltage proportional to ambient temperature.
INV (Pin 12): Control Input Pin to Invert the Polarity of
the Difference Output VODF.
RT2 (Pin 14): Second Order Output Temperature Compen-
sation Pin for Both Channels. Connect this pin to ground
to disable. The output voltage will increase or decrease
with the ambient temperature by connecting this pin to
ground via an off-chip resistor, depending on the polarity
set by RP2 pin.
VOS (Pin 15): Input Pin for Setting the DC Offset of the
Difference Output VODF. It is recommended to set this DC
offset such that V
ODF
does not fall below 100mV.
VODF (Pin 16): DC Difference Output. This voltage is equal
to the difference of the two channels’ output voltages,
plus a DC offset:
V
ODF = (VOA – VOB) + VOS, if INV pin is held low, (<1V)
V
ODF = (VOB – VOA) + VOS, if INV pin is held high, (>2V)
RT1 (Pin 17): First Order Output Temperature Compen-
sation Pin for Both Channels. Connect this pin to ground
to disable. The output voltage will increase or decrease
with the ambient temperature by connecting this pin to
ground via an off-chip resistor, depending on the polarity
set by RP1 pin.
VOA, VOB (Pins 18, 13): DC Output of Channel A and
Channel B, respectively.
VCCN (Pin 19): Power Supply Pin for the Envelope Detec-
tors in Both Channels. Typical total current consumption
of this pin is 9.6mA. This pin should be bypassed with 1nF
and 1µF capacitors. Connect this pin to ground to disable
the envelope detectors.
ENVA, ENVB (Pins 20, 11): Envelope Detector Output Pins
for Channel A and Channel B, respectively. Each output
tracks the input signal’s RF envelope and outputs a DC
voltage directly proportional to the signal power, normal-
ized to the average power.
FLTA, FLTB (Pins 21, 10): Connection for an External Filter-
ing Capacitor for Channel A and Channel B, respectively. A
minimum 8nF capacitor is required for stable AC average
power measurement. Each capacitor should be connected
between FLTA and VCCA, and between FLTB and VCCB.
RP1 (Pin 22): Pin for Setting Polarity of First Order Output
Temperature Compensation. Connect this pin to ground
to change the output voltage proportional to ambient
temperature. Float this pin to change the output voltage
inversely proportional to ambient temperature.
IN+A, IN–A, IN+B, IN–B (Pins 24, 23, 7, 8): Differential
RF Input Signal Pins for Channel A and Channel B. Each
channel can be driven with a single-ended or differential
signal. These pins are internally biased to 1.6V and should
be DC-blocked externally. The differential impedance is
400.
GND (Exposed Pad Pin 25): Circuit Ground Return for
the Entire IC. This must be soldered to the printed circuit
board ground plane.