SKY73013-306 Datasheet, PDF (6/7 Pages) Skyworks Solutions Inc. – Direct Quadrature Demodulator 4.9-5.925 GHz Featuring No-Pull LO Architecture

PRELIMINARY DATA SHEET • SKY73013-306
Evaluation Board Test Procedure for Evaluating
Noise Floor
This is procedure assumes that circuit is set up according to the
procedure described above.
1. Reduce the input RF level to -60 dBm
2. Connect 5 V to the 5 V pin on header 4 to power the
differential amplifiers U2 and U3.
3. Move the Oscilloscope probes to the I+, I-, Q+ and Q- pins of
header 3. The differential amplifiers are included in the signal
path because the IF output signals directly from the I and Q
baseband outputs of the SKY73013 are smaller than the
minimum required by most oscilloscopes to make a reasonable
measurement, although these signal levels are well within the
dynamic range of almost any op amp or variable gain amplifier.
4. Adjust RF signal generator level until demodulated noise is
approximately equal to that of the downconverted sinusoid
output level. This input signal level corresponds to the input-
referred noise floor, the input level at which the output SNR
is 0 dB.
Circuit Design Considerations
The following design considerations are general in nature and
must be followed regardless of final use or configuration.
1. Paths to ground should be made as short as possible, with
lowest possible impedance.
2. The ground pad of the SKY73013 direct quadrature
demodulator has special electrical and thermal grounding
requirements. This pad is the main thermal conduit for heat
flow from the die to the circuit board. As such, design the
printed circuit board ground pad to dissipate the maximum
heat produced by the SKY73013 and ensure that the method
used to electrically and mechanically connect the SKY73010
package to this ground pad is adequate to allow for this
heat flow.
3. Two external bypass capacitors on the Vcc pin are recom-
mended. One larger-value capacitor should be used for low
frequency bypassing and the other, smaller value capacitor
for high frequency bypassing. The smaller capacitor should
be physically located as near as possible to the SKY73013
V_CC pin. Special attention should be given to ensure that the
selected smaller capacitor does not go into parallel self
resonance at the RF frequency.
4. The RF and LO inputs must be driven differentially for optimal
performance. A 1:1 impedance balun is recommended for each
with a center tap on the secondary side that is DC grounded.
Special attention should be paid to ensure that the center tap
has access to as “clean” a ground as possible.
Evaluation Board Components
Component
C1, C3, C8, C12, C17
C2, C4
C6
C7, C23
C10, C25, C26, C27
C13, C14
C15, C18, C22, C24
C20
C21
C28, C29, C30
H1, H3
H2, H4
L5, L6, L8
R1
R2
R3, R5, R6, R9
R4, R7, R8
RFC1, RFC2, RFC3
U1
U2, U3
Description
Do not place
0.5 pF
10 pF
100 pF
5 pF
2.7 pF
1000 pF
1 pF
0Ω
0.1 µF
8-pin SMT header
4-pin header
0Ω
1.2 k Ω 1%
500 Ω
39k Ω
500 Ω
SMA connector
SKY73013
AD8318ARM
Default
0201
0804
0603
0201
0402
0402
0402
0402
0402
0402
0402
0402
0402
0402
QFN-16 (4 X 4mm)
Pin 1
Indicator
0.157
(4.00 mm)
0.085 (2.15 mm)
+ 0.004 (0.10 mm)
- 0.006 (0.15 mm)
Exposed Pad
0.008 (0.20 mm)
Seating Plane
0.157
(4.00 mm)
0.042
(1.075 mm)
0.0008
(0.02 mm)
+0.001
(0.03 mm)
-0.0008
(0.02 mm)
0.035 (0.90 mm)
± 0.004 (0.10 mm)
0.077
(1.950 mm)
0.085 (2.15 mm)
+ 0.004 (0.10 mm)
- 0.006 (0.15 mm)
0.077 (1.950 mm)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
6
August 18, 2006 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • 200508 Rev. B