LT5578 Datasheet, PDF (1/16 Pages) Linear Technology – 0.4GHz to 2.7GHz High Linearity Upconverting Mixer

FEATURES
n _{High Output IP3: 27dBm at 0.9GHz}
24.3dBm at 1.95GHz
n _{Low Noise Floor: –158dBm/Hz (POUT = –5dBm)}
n _{High Conversion Gain: 1.4dB at 0.9GHz}
n _{Noise Figure: 8.6dB}
n _{Low LO-RF Leakage: –43dBm}
n _{Single-Ended RF and LO Ports}
n _{Low LO Drive Level: –1dBm}
n _{Single 3.3V Supply}
n _{5mm × 5mm QFN24 Package}
(Pin Compatible with LT5579)
APPLICATIONS
n _{GSM 900PCS/1800PCS and W-CDMA Infrastructure}
n _{LTE and WiMAX Basestations}
n _{Wireless Repeaters}
n _{Public Safety Radios}
LT5578
0.4GHz to 2.7GHz
High Linearity
Upconverting Mixer
DESCRIPTION
The LT^®5578 mixer is a high performance upconverting
mixer optimized for frequencies in the 0.4GHz to 2.7GHz
range. The single-ended LO input and RF output ports
simplify board layout and reduce system cost. The mixer
needs only –1dBm of LO power and the balanced design
results in low LO signal leakage to the RF output. At
1.95GHz operation, the LT5578 provides conversion gain
of –0.7dB, high OIP3 of 24.3dBm and a low noise floor of
–158dBm/Hz at a –5dBm RF output signal level.
The LT5578 offers a high performance alternative to pas-
sive mixers. Unlike passive mixers, which have conversion
loss and require high LO drive levels, the LT5578 delivers
conversion gain at significantly lower LO input levels and
is less sensitive to LO power level variations. The lower
LO drive level requirements, combined with the excellent
LO leakage performance, translate into lower LO signal
contamination of the output signal.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
Frequency Upconversion in LTE Transmitter
LO INPUT
–1dBm
2.7pF
6.8pF
LT5578
13.7Ω
BIAS
IF
140MHz
TC4-1W+
4:1
220pF
100nH
IF⁺
39pF
IF^–
220pF
100nH
13.7Ω
LO
GND
RF
22nH
2pF
10μF
V_CC
100μF
5579 TA01a
1nF
V_CC
3.3V
RF
700MHz
13nH ^{TO 950MHz}
2.7pF
Gain, NF and OIP3 vs
RF Output Frequency
30
OIP3
25
20
T_A = 25°C
f_IF = 140MHz
15
f_LO = f_RF – f_IF
10
SSB NF
5
GAIN
0
650 700 750 800 850 900 950 1000
RF OUTPUT FREQUENCY (MHz)
5578 TA01b
5578f
1