LT5519
5
5519f
Conversion Gain vs IF Input
Power (One Input Tone)
Conversion Gain, IIP3 and IIP2
vs Supply Voltage
IF, LO and RF Port Return Loss
vs Frequency
TYPICAL PERFOR A CE CHARACTERISTICS
UW
V
CC
= 5V
DC
, EN = High, T
A
= 25°C, IF input = 140MHz at –10dBm, LO input = 1.14GHz at –5dBm, RF output measured at 1000MHz,
unless otherwise noted. For 2-tone inputs: 2nd IF input = 141MHz at –10dBm. (Test Circuit Shown in Figure 2.)
IF INPUT POWER (dBm)
–16
GAIN (dB)
0
2
4
0
5519 G12
–2
–4
–1
1
3
–3
–5
–6
–12
–8
–4
4
T
A
= 85°C
T
A
= 25°C
T
A
= –40°C
FREQUENCY (MHz)
0
–30
RETURN LOSS (dB)
–25
–20
–15
–10
–5
0
500 1000 1500 2000
5519 G13
IF PORT RF PORT
LO PORT
SUPPLY VOLTAGE (V)
4
–2
GAIN (dB)
IIP3, IIP2 (dBm)
0
2
IIP3
IIP2
4
6
10
4.25
4.5 4.75 5
5519 G14
5.25 5.5
8
0
10
GAIN
20
30
40
60
50
LOW SIDE LO
LOW SIDE LO
LOW SIDE AND HIGH SIDE LO
HIGH SIDE LO
HIGH SIDE LO
UU
U
PI FU CTIO S
GND (Pins 1, 4, 9, 12, 13, 16): Internal Grounds. These
pins are used to improve isolation and are not intended as
DC or RF grounds for the IC. Connect these pins to low
impedance grounds on the PCB for best performance.
IF
+
, IF
–
(Pins 2, 3): Differential IF Signal Inputs. A differ-
ential signal must be applied to these pins through DC
blocking capacitors. The pins must be connected to ground
with 100Ω resistors (the grounds must each be capable of
sinking about 18mA). For best LO leakage performance,
these pins should be DC isolated from each other. An
impedance transformation is required to match the IF in-
put to the desired source impedance (typically 50Ω or 75Ω).
EN (Pin 5): Enable Pin. When the applied voltage is greater
than 3V, the IC is enabled. When the applied voltage is less
than 0.5V, the IC is disabled and the DC current drops to
about 1µA.
V
CC1
(Pin 6): Power Supply Pin for the Bias Circuits.
Typical current consumption is about 2mA. This pin
should be externally connected to V
CC
and have appropri-
ate RF bypass capacitors.
V
CC2
(Pin 7): Power Supply Pin for the LO Buffer Circuits.
Typical current consumption is about 22mA. This pin
should have appropriate RF bypass capacitors as shown
in Figure␣ 2. The 1000pF capacitor should be located as
close to the pins as possible.
V
CC3
(Pin 8): Power Supply Pin for the Internal Mixer.
Typical current consumption is about 36mA. This pin
should be externally connected to V
CC
through an induc-
tor. A 39nH inductor is shown in Figure 2, though the value
is not critical.
RF
–
, RF
+
(Pins 10, 11): Differential RF Outputs. One pin
may be DC connected to a low impedance ground to realize
a 50Ω single-ended output. No external matching compo-
nents are required. A DC voltage should not be applied
across these pins, as they are internally connected through
a transformer winding.
LO
+
, LO
–
(Pins 14, 15): Differential Local Oscillator In-
puts. The LT5519 works well with a single-ended source
driving the LO
+
pin and the LO
–
pin connected to a low
impedance ground. No external 50Ω matching compo-
nents are required. An internal resistor is connected
across these pins; therefore, a DC voltage should not be
applied across the inputs.
Exposed Pad (Pin 17): DC and RF ground return for the
entire IC. This must be soldered to the printed circuit board
low impedance ground plane.
