lt5525 Linear Technology Corporation, lt5525 Datasheet - Page 11

• Manufacturer Part Number: lt5525
• Description: High Linearity, Low Power Downconverting Mixer
• Manufacturer: Linear Technology Corporation

APPLICATIO S I FOR ATIO
Conversion gain and IIP3 performance with an RF fre-
quency of 1900MHz are plotted vs IF frequency in Figure
13. These results show that the usable IF bandwidth for the
lumped element balun is greater than 60MHz, assuming
tight tolerance matching components. Contact the factory
for applications assistance with this circuit.
TYPICAL APPLICATIO S
–10
–15
–20
–25
–5
0
200
Figure 12. Typical IF Return Loss
Performance with 240MHz,
360MHz and 450MHz Lumped
Element Baluns
250
300
FREQUENCY (MHz)
U
350
Top Layer Silkscreen
400
U
450
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
5525 F12
U
500
W
20
–5
15
10
5
0
200
Figure 13. Typical Gain and IIP3 vs
IF Frequency with 240MHz,
360MHz and 450MHz Lumped
Element Baluns
U
IIP3
GAIN
Evaluation Board Layouts
250
IF FREQUENCY (MHz)
300
350
Table 4. Component Values for Lumped Balun
IF FREQ (MHz)
400
T
f
f
P
P
240
360
450
LO
RF
A
LO
RF
= 25°C
= f
= 1900MHz
= –5dBm
= –15dBm
RF
450
– f
5525 F13
IF
500
L11, L12 (nH) C11, C12 (pF) C13 (pF) L14 (nH)
100
68
56
Top Layer Metal
20
19
18
17
16
15
14
13
12
11
10
1200
Figure 14. Typical IIP3 vs RF
Frequency with Lumped Element
Baluns and IF Frequencies of
240MHz, 360MHz and 450MHz
T
f
P
P
LO
A
LO
RF
= 25°C
1400
= f
= –5dBm
= –15dBm
RF
3.9
2.7
2.2
– f
1600
RF FREQUENCY (MHz)
IF
1800
2000 2200
100
8.2
10
LT5525
11
240MHz
360MHz
450MHz
2400 2600
560
270
180
5525 F14
5525f