LT5516 Datasheet, PDF (1/12 Pages) Linear Technology – 800MHz to 1.5GHz Direct Conversion Quadrature Demodulator

LT5516
800MHz to 1.5GHz Direct
Conversion Quadrature Demodulator
FEATURES
s _{Frequency Range: 800MHz to 1.5GHz}
s _{High IIP3: 21.5dBm at 900MHz}
s _{High IIP2: 52dBm}
s _{Noise Figure: 12.8dB at 900MHz}
s _{Conversion Gain: 4.3dB at 900MHz}
s _{I/Q Gain Mismatch: 0.2dB}
s _{Shutdown Mode}
s _{16-Lead QFN 4mm × 4mm Package}
with Exposed Pad
U
APPLICATIO S
s _{Cellular/PCS/UMTS Infrastructure}
s _{High Linearity Direct Conversion I/Q Receiver}
s _{High Linearity I/Q Demodulator}
DESCRIPTIO
The LT^®5516 is an 800MHz to 1.5GHz direct conversion
quadrature demodulator optimized for high linearity re-
ceiver applications. It is suitable for communications
receivers where an RF or IF signal is directly converted into
I and Q baseband signals with bandwidth up to 260MHz.
The LT5516 incorporates balanced I and Q mixers, LO
buffer amplifiers and a precision, high frequency quadra-
ture generator.
In an RF receiver, the high linearity of the LT5516 provides
excellent spur-free dynamic range, even with fixed gain
front end amplification. This direct conversion receiver
can eliminate the need for intermediate frequency (IF)
signal processing, as well as the corresponding require-
ments for image filtering and IF filtering. Channel filtering
can be performed directly at the outputs of the I and Q
channels. These outputs can interface directly to channel-
select filters (LPFs) or to a baseband amplifier.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
BPF
BPF
RF⁺
LNA
RF ^–
LO⁺
LO INPUT
LO^–
ENABLE
EN
5V
V_CC
0°/90°
LT5516
I_OUT+
LPF
VGA
I_OUT–
0°
DSP
Q_OUT+
LPF
VGA
Q_OUT–
90°
5516 F01
Figure 1. High Signal-Level I/Q Demodulator for Wireless Infrastructure
I/Q Output Power, IM3 vs
RF Input Power
20
0
P_OUT
–20
–40
–60
–80
–100
–18
IM3
V_CC = 5v
T_A = 25°C
P_LO = –10dBm
f_LO = 901MHz
f_RF1 = 899.9MHz
f_RF2 = 900.1MHz
–14 –10 –6 –2 2
6
RF INPUT POWER (dBm)
5516 TA01
5516f
1