LT5520EUF Linear Technology, LT5520EUF Datasheet - Page 9

• Manufacturer Part Number: LT5520EUF
• Description: IC MIXER UPCONV 1.3-2.3GHZ 16QFN
• Manufacturer: Linear Technology
• Series: LT5520r

Specifications of LT5520EUF

• Rf Type: General Purpose
• Frequency: 1.3GHz ~ 2.3GHz
• Number Of Mixers: 1
• Gain: -1dB
• Noise Figure: 15dB
• Secondary Attributes: Up Converter
• Current - Supply: 70mA
• Voltage - Supply: 4.5 V ~ 5.25 V
• Package / Case: 16-WQFN Exposed Pad
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIO S I FOR ATIO
Figures 6-8 illustrate the performance versus tuned IF
input frequency with both high side and low side LO
injection. Figure 6 shows the measured conversion gain
and IIP3. The noise figure is plotted in Figure 7 for LO
power levels of –5dBm and 0dBm. At lower input frequen-
cies, the LO power level has little impact on noise figure.
However, for higher frequencies, an increased LO drive
level may be utilized to achieve better noise figure. The
single-tone IIP2 behavior is illustrated in Figure 8.
Figure 8. IIP2 vs Tuned IF Input Frequency
60
50
40
30
20
10
0
0
100
U
INPUT FREQUENCY (MHz)
LOW SIDE LO
200
HIGH SIDE LO
U
300
400
500
W
600
5520 F08
700
U
Low Frequency Matching of the RF Output Port
Without any external components on the RF output, the
internal transformer of the LT5520 provides a good 50
impedance match for RF frequencies above approximately
1600MHz. At frequencies lower than this, the return loss
drops below 10dB and degrades the conversion gain. The
addition of a single 3.3pF capacitor in series with the RF
output improves the match at lower RF frequencies,
shifting the 10dB return loss point to about 1300MHz, as
demonstrated in Figure 9. This change also results in an
improvement of the conversion gain, as shown in
Figure 9.
Figure 9. Conversion Gain and Return Loss vs Output Frequency
–1
–2
–3
–4
–5
–6
–7
–8
–9
1
0
1200
C
OUT
C
OUT
1400
= 3.3pF
= 3.3pF
1600
FREQUENCY (MHz)
NO C
OUT
1800
RETURN LOSS
2000
GAIN
NO C
2200
OUT
5520 F09
2400
LT5520
0
–5
–10
–15
–20
–25
9
5520f