lt5518 Linear Technology Corporation, lt5518 Datasheet - Page 6

• Manufacturer Part Number: lt5518
• Description: 1.5ghz?2.4ghz High Linearity Direct Quadrature Modulator
• Manufacturer: Linear Technology Corporation

PI FU CTIO S
LT5518
TYPICAL PERFOR A CE CHARACTERISTICS
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
turning on ESD protection diodes.
BBPQ, BBMQ (Pins 7, 5): Baseband Inputs for the Q-Chan-
nel, with 2.9kΩ Differential Input Impedance. Internally
6
P
or LO feedthrough nulling. f
unless otherwise noted. (Note 3)
LO
U
= 0dBm. BBPI, BBMI, BBPQ, BBMQ inputs 2.06V
U
65
60
55
50
45
40
35
U
1.3
Output IP2 vs LO Frequency
RF
1.5
= f
5V, T
5V, T
5V, T
4.5V, T
5.5V, T
W
CC
BB
1.7
A
A
A
LO FREQUENCY (GHz)
= –40°C
= 25°C
= 85°C
A
A
+ f
+ 0.5V in order to avoid
= 25°C
= 25°C
LO
U
1.9
(upper sideband selection). P
f
f
f
BB,1
BB,2
IM2
2.1
= f
= 2MHz
= 2.1MHz
BB,1
2.3
+ f
BB,2
DC
2.5
, Baseband Input Frequency f
+ f
5518 G19
LO
2.7
biased at about 2.06V. Applied common mode voltage
must stay below 2.5V.
V
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
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.
RF, OUT
CC
(Pins 8, 13): Power Supply. Pins 8 and 13 are con-
–10
–20
–30
–40
–50
= –10dBm (–10dBm/tone for 2-tone measurements),
0
1.3
LO and RF Port Return Loss
vs RF Frequency
RF PORT, EN = HIGH,
V
BB
RF PORT, EN =
1.5
CC
HIGH, NO LO
= 2MHz, I and Q 90° shifted without image
= 5V, EN = High, T
P
1.7
RF FREQUENCY (GHz)
LO
= 0dBm
1.9
2.1
LO PORT, EN = LOW
RF PORT,
EN = LOW
2.3
A
LO PORT,
EN = HIGH
= 25°C, f
2.5
5518 G20
2.7
CC
LO
+ 0.5V in order
= 2.14GHz,
5518f