LT5522
8
5522fa
BLOCK DIAGRA
W
2
HIGH SPEED
LO BUFFER
LINEAR
AMPLIFIER
IF
+
RF
+
3
RF
–
15
LO
+
14
LO
–
LIMITER
V
CC2
5522 BD
11
GND
DOUBLE BALANCED
MIXER
12
GND
9
EN
5
7
IF
–
10
V
CC1
6
EXPOSED
PAD
17
BIAS
UU
U
PI FU CTIO S
NC
(Pins 1, 4, 8, 13, 16): Not Connected Internally. These
pins should be grounded on the circuit board for improved
LO to RF and LO to IF isolation.
RF
+
, RF
–
(Pins 2, 3): Differential Inputs for the RF Signal.
The RF input signal should be applied to the RF
–
pin (Pin
3) and the RF
+
pin (Pin 2) must be connected to ground.
These pins are the primary side of the RF input balun which
has low DC resistance. If the RF source is not DC blocked,
then a series blocking capacitor must be used.
EN
(Pin 5): Enable Pin. When the input enable voltage is
higher than 3V, the mixer circuits supplied through Pins 6,
7, 10 and 11 are enabled. When the input enable voltage is
less than 0.3V, all circuits are disabled. Typical input EN pin
current is 55µA for EN = 5V and 0µA when EN = 0V. The EN
pin should not be left floating. Under no conditions should
the EN pin voltage exceed V
CC
+ 0.3V, even at start-up.
V
CC1
(Pin 6): Power Supply Pin for the LO Buffer Circuits.
Typical current consumption is 22mA. This pin should be
externally connected to the V
CC2
pin and decoupled with
0.01µF and 3.3µF capacitors.
V
CC2
(Pin 7): Power Supply Pin for the Bias Circuits.
Typical current consumption is 4mA. This pin should be
externally connected to the V
CC1
pin and decoupled with
0.01µF and 3.3µF capacitors.
GND (Pins 9, 12): Ground. These pins are internally
connected to the backside ground for improved isolation.
They should be connected to RF ground on the circuit
board, although they are not intended to replace the
primary grounding through the backside contact of the
package.
IF
–
, IF
+
(Pins 10, 11): Differential Outputs for the IF
Signal. An impedance transformation may be required to
match the outputs. These pins must be connected to V
CC
through impedance matching inductors, RF chokes or a
transformer center-tap.
LO
–
, LO
+
(Pins 14, 15): Differential Inputs for the Local
Oscillator Signal. The LO input can also be driven single
ended by connecting one input to ground. These pins are
internally matched for 50Ω single-ended operation. If the
LO source is not AC-coupled, then a series blocking
capacitor must be used.
Exposed Pad (Pin 17): Circuit Ground Return for the
Entire IC. This must be soldered to the printed circuit board
ground plane.
