LT5518
6
5518f
Output IP2 vs LO Frequency
LO and RF Port Return Loss
vs RF Frequency
EN (Pin 1): Enable Input. When the enable pin voltage is
higher than 1V, the IC is turned on. When the input voltage
is less than 0.5V, the IC is turned off.
GND (Pins 2, 4, 6, 9, 10, 12, 15): Ground. Pins 6, 9, 15
and 17 (exposed pad) are connected to each other internally.
Pins 2 and 4 are connected to each other internally and
function as the ground return for the LO signal. Pins 10
and 12 are connected to each other internally and function
as the ground return for the on-chip RF balun. For best RF
performance, pins 2, 4, 6, 9, 10, 12, 15 and the Exposed
Pad (Pin 17) should be connected to the printed circuit
board ground plane.
LO (Pin 3): LO Input. The LO input is an AC-coupled single-
ended input with approximately 50Ω input impedance at
RF frequencies. Externally applied DC voltage should be
within the range –0.5V to V
CC
+ 0.5V in order to avoid
turning on ESD protection diodes.
BBPQ, BBMQ (Pins 7, 5): Baseband Inputs for the Q-Chan-
nel, with 2.9kΩ Differential Input Impedance. Internally
biased at about 2.06V. Applied common mode voltage
must stay below 2.5V.
V
CC
(Pins 8, 13): Power Supply. Pins 8 and 13 are con-
nected to each other internally. It is recommended to use
0.1µF capacitors for decoupling to ground on each of
these pins.
RF (Pin 11): RF Output. The RF output is an AC-coupled
single-ended output with approximately 50Ω output im-
pedance at RF frequencies. Externally applied DC voltage
should be within the range –0.5V to V
CC
+ 0.5V in order
to avoid turning on ESD protection diodes.
BBPI, BBMI (Pins 14, 16): Baseband Inputs for the I-Chan-
nel, with 2.9kΩ Differential Input Impedance. Internally
biased at about 2.06V. Applied common mode voltage
must stay below 2.5V.
Exposed Pad (Pin 17): Ground. This pin must be soldered
to the printed circuit board ground plane.
LO FREQUENCY (GHz)
1.3
OIP2 (dBm)
65
60
55
50
45
40
35
1.9 2.3
5518 G19
1.5 1.7
2.1 2.5 2.7
f
BB,1
= 2MHz
f
BB,2
= 2.1MHz
f
IM2
= f
BB,1
+ f
BB,2
+ f
LO
5V, T
A
= –40°C
5V, T
A
= 25°C
5V, T
A
= 85°C
4.5V, T
A
= 25°C
5.5V, T
A
= 25°C
RF FREQUENCY (GHz)
1.3
S
11
(dB)
0
–10
–20
–30
–40
–50
1.9 2.3
5518 G20
1.5 1.7
2.1 2.5 2.7
LO PORT, EN = LOW
RF PORT, EN = HIGH,
P
LO
= 0dBm
RF PORT,
EN = LOW
LO PORT,
EN = HIGH
RF PORT, EN =
HIGH, NO LO
V
CC
= 5V, EN = High, T
A
= 25°C, f
LO
= 2.14GHz,
P
LO
= 0dBm. BBPI, BBMI, BBPQ, BBMQ inputs 2.06V
DC
, Baseband Input Frequency f
BB
= 2MHz, I and Q 90° shifted without image
or LO feedthrough nulling. f
RF
= f
BB
+ f
LO
(upper sideband selection). P
RF, OUT
= –10dBm (–10dBm/tone for 2-tone measurements),
unless otherwise noted. (Note 3)
TYPICAL PERFOR A CE CHARACTERISTICS
UW
PI FU CTIO S
UUU
