DC1437B-AB Linear Technology, DC1437B-AB Datasheet - Page 16

• Manufacturer Part Number: DC1437B-AB
• Description: BOARD EVAL LTM9003-AB
• Manufacturer: Linear Technology
• Type: Pre-Distortion Receiver Subsystemr

Specifications of DC1437B-AB

• Design Resources: DC1437 Schematic
• Frequency: 184MHz
• Features: LTM9003 12bit Predistortion Receiver Subsystem, LVDS Output
• Tool / Board Applications: Wireless Connectivity-ZigBee, RF, Infrared, USB
• Mcu Supported Families: LTM9003
• Development Tool Type: Hardware - Eval/Demo Board
• For Use With/related Products: LTM9003
• Lead Free Status / RoHS Status: Not applicable / Not applicable

LTM9003
applicaTions inForMaTion
Table 1b. RF Input Impedance vs Frequency (LTM9003-AB)
LO Input Port
The mixer’s LO input, shown in Figure 6, is internally
matched from 0.9GHz to 3.5GHz. LO input matching near
600MHz requires the series inductor (L4)/shunt capaci-
tor (C4) network shown in Figure 6. Likewise, the 2GHz
match can be improved by using L4 = 2.7µH, C4 = 0.5pF .
Measured LO input return losses for these three cases
are plotted in Figure 7.
The optimum LO drive is –3dBm for LO frequencies above
1.2GHz, although the amplifiers are designed to accommo-
date several dB of LO input power variation without significant
mixer performance variation. Below 1.2GHz, 0dBm LO drive
is recommended for optimum noise figure, although –3dBm
will still deliver good conversion gain and linearity.

FREQUENCY
(MHz)
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
500
600
700
800
900
INPUT IMPEDANCE
19.8 + j7.3
25.7 + j6.6
28.8 + j5.9
32.3 + j5.1
36.1 + j3.9
40.5 + j2.6
45.4 + j1.1
50.8 – j0.2
56.3 – j0.9
61.4 – j0.7
65.3 + j0.5
67.4 + j2.4
67.3 + j4.1
65.7 + j5.1
63.2 + j5.2
60.4 + j4.7
57.6 + j3.7
52.4 + j1.3
47.4 – j1.4
44.8 – j2.7
41.9 – j3.9
35.7 – j5.9
22.7 + j7
55 + j2.6
39 – j5
49.9
MAG
0.59
0.55
0.51
0.47
0.42
0.38
0.32
0.26
0.15
0.12
0.14
0.19
0.25
0.31
0.37
0.42
0.46
0.49
0.51
0.53
0.54
0.55
0.55
0.55
0.54
0.2
S11
–101.6
–106.3
–111.9
ANGLE
138.4
133.9
129.2
123.9
117.9
110.6
101.3
–13.1
–37.9
–52.4
–61.9
–68.9
–74.4
–79.1
–86.7
–90.1
–93.7
–97.3
87.6
65.6
27.5
143
–83
Custom matching networks can be designed using the port
impedance data listed in Table 2. This data is referenced
to the LO pin with no external matching.
Table 2a. LO Input Impedance vs Frequency (LTM9003-AA)
LO
IN
FREQUENCY
FOR LO < 1GHz
(MHz)
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
MATCHING
500
600
700
800
900
EXTERNAL
C4
L4
Figure 6. LO Input Schematic
INPUT IMPEDANCE
LO
LTM9003
109.7 – j42.2
206.6 – j35.9
115.4 + j59.4
86.7 + j35.2
70.7 + j18.5
183.8 + j70
V
10.3 – j6.1
18.7 + j8.2
64.5 – j9.9
59.3 + j7.4
50.2 + j0.2
42.6 – j4.5
35.9 – j7.2
30.2 – j8.3
25.6 – j8.1
22.4 – j6.7
20.8 – j4.6
21.5 – j2.1
28.9 + j1.3
35.3 + j1.5
42.6 + j0.9
57.7 – j0.6
9.7 + j2.2
37 + j6.2
CC2
24.2
50.3
REGULATOR
MAG
0.73
0.68
0.64
0.59
0.63
0.66
0.68
0.71
0.68
0.66
0.63
0.59
0.54
0.48
0.42
0.35
0.28
0.21
0.16
0.12
0.6
0.6
0.7
0.7
0.7
0.1
S11
LIMITER
V
REF
–159.1
–109.2
–118.9
–129.2
–140.3
–152.3
–165.5
–179.8
ANGLE
172.4
141.8
108.4
–17.1
–37.3
–53.7
–67.4
–79.2
–89.7
–99.6
163.9
145.1
121.1
72.7
38.3
88.6
45.8
7.9
9003 F06
TO
MIXER
9003f