HMC525ALC4 Data Sheet
Rev. A | Page 26 of 28
APPLICATIONS INFORMATION
TYPICAL APPLICATION CIRCUIT
Figure 101 shows the typical application circuit for the
HMC525ALC4. To select the appropriate sideband, an external
90° degree hybrid is needed. For applications not requiring
operation to dc, use an off-chip dc blocking capacitor. For
applications that require suppression of the LO signal at the
output, use a bias tee or RF feed as shown in Figure 101. Ensure
that the source or sink current used for LO suppression is
<2 mA for each IF port to prevent damage to the device. The
common-mode voltage for each IF port is 0 V.
To select the upper sideband when using as an upconverter,
connect the IF1 pin to the 90° port of the hybrid, and connect
the IF2 pin to the 0° port of the hybrid. To select the lower
sideband, connect IF1 to the 0° port of the hybrid and IF2 to the
90° port of the hybrid. The input is from the sum port of the
hybrid and the difference port is 50 Ω terminated.
To select the upper sideband (low-side LO) when using as
downconverter, connect the IF1 pin to the 0° port of the hybrid,
and connect the IF2 pin to the 90° port of the hybrid. To select
the lower sideband (high-side LO), connect the IF1 pin to the
90° port of the hybrid and IF2 to the 0° port of the hybrid. The
output is from the sum port of the hybrid, and the difference
port is 50 Ω terminated.
13
1
3
4
2
7
5
6
14
15
16
17
18
90°
HYBRID
RF LO
8
9
10
11
12
19
GND
IF1 IF2
20
21
22
23
24
PACKAGE
BASE
16401-109
50Ω IF
SUPPLY
FOR IF1
SUPPLY
FOR IF2
BIAS TEE/
DC FEED FOR IF2
BIAS TEE/
DC FEED FOR IF1
DC BLOCKING
CAPACITORS
EXTERNAL
90° HYBRID
NOTES
1. DASHED SECTIONS ARE OPTIONAL AND MEANT FOR LO NULLING.
Figure 101. Typical Application Circuit
EVALUATION PCB INFORMATION
Use RF circuit design techniques for the circuit board used in
the application. Ensure that signal lines have 50 Ω impedance
and connect the package ground leads and the exposed pad
directly to the ground plane (see Figure 103). Use a sufficient
number of via holes to connect the top and bottom ground planes.
The evaluation circuit board shown in Figure 103 is available
from Analog Devices, Inc., upon request.
Table 7. Materials for Evaluation PCB EV1HMC525ALC4
Item Description
PCB
1
PCB, 109996-1
J1, J2 2.92 mm SubMiniature Version A (SMA) connectors, SRI
connector gage
J3, J4 Gold plated SMA, edge mount with 0.02 inch pin
connectors, Johnson SMA connectors
U1 Device under test, HMC525ALC4
1
109996-1 is the raw bare PCB identifier. Reference EV1HMC525ALC4 when
ordering complete evaluation PCB.
