LT5560
10
5560f
PI FU CTIO S
UUU
LO
–
, LO
+
(Pins 1, 8): Differential Inputs for the Local
Oscillator Signal. The LO input impedance is approxi-
mately 180Ω, thus external impedance matching is
required. The LO pins are internally biased to approxi-
mately 1V below V
CC
; therefore, DC blocking capacitors
are required. The LT5560 is characterized and production
tested with a single-ended LO drive, though a differential
LO drive can be used.
EN (Pin 2): Enable Pin. An applied voltage above 2V will
activate the IC. For V
EN
below 0.3V, the IC will be shut
down. If the enable function is not required, then this pin
should be connected to V
CC
. The typical enable pin input
current is 25µA for EN = 3V. The enable pin should not be
allowed to fl oat because the mixer may not turn on reliably.
Note that at no time should the EN pin voltage be allowed
to exceed V
CC
by more than 0.3V.
IN
+
, IN
–
(Pins 3, 4): Differential Inputs. These pins should be
driven with a differential signal for optimum performance.
Each pin requires a DC current path to ground. Resistance
to ground will cause a decrease in the mixer current. With
0Ω resistance, approximately 6mA of DC current fl ows
out of each pin. For lowest LO leakage to the output, the
DC resistance from each pin to ground should be equal.
An impedance transformation is required to match the
differential input to the desired source impedance.
OUT
–
, OUT
+
(Pins 5, 6): Differential Outputs. An imped-
ance transformation may be required to match the outputs.
These pins require a DC current path to V
CC
.
V
CC
(Pin 7): Power Supply Pin for the Bias Circuits.
Typical current consumption is 1.5mA. This pin should
be externally bypassed with a 1nF chip capacitor.
Exposed Pad (Pin 9): PGND. Circuit Ground Return for
the Entire IC. This must be soldered to the printed circuit
board ground plane.
