SKY73208-11 Datasheet, PDF (3/17 Pages) Skyworks Solutions Inc. – 350-5000 MHz Wideband Receive Mixer with Integrated Integer-N PLL and VCO

Table 1. SKY73208-11 Signal Descriptions
Pin
Name
Description
1
LD
Lock detect output
2
VDD_DIG
+3.3 V supply for digital blocks
3
VDD_CLK
+3.3 V supply for reference buffer
4
REF_CLK
Reference clock input
5
EXT_VCO_INP
External VCO positive input
6
EXT_VCO_INN
External VCO negative input
7
LE
Latch enable input for SPI
8
DATA
Data input for SPI
9
CLK
Clock input for SPI
10 N/C
No connection
11 N/C
No connection
12 N/C
No connection
13 N/C
No connection
14 N/C
No connection
15 GND
Ground
16 VDD_VCO
+3.3 V supply for VCO
17 VCO_RES
External 15 kΩ resistor to set VCO bias
18 VDD_OBUF
+3.3 V supply for output LO buffer
DATA SHEET • SKY73208-11 MIXER WITH PLL AND VCO
Pin
Name
19 OUT_BUFN
20 OUT_BUFP
21 GND
22 VDD_LO
23 IF_OUTN
24 IF_OUTP
25 VDD_IF
26 EXT_PD
27 MIX_RES
28 VDD_MIXBIAS
29 RF_IN
30 LO_RES
31 VDD_MIX
32 VDD_DIV
33 VCTRL
34 VDD_PLL
35 VDD_CP
36 ICP
Description
LO negative output
LO positive output
Ground
+5 V supply for mixer LO buffer
Negative IF output
Positive IF output
+5 V supply for mixer output
Power-down control pin for mixer
External bias resistor for mixer
+5 V supply for mixer bias
RF mixer input
External bias resistor for LO chain
+5 V supply for mixer
+3.3 V supply for LO dividers
Tuning voltage for VCO
+3.3 V supply for PLL
+3.3 V supply for charge pump
Charge pump output
Functional Description
The SKY73208-11 is comprised of four main functional blocks:
 RF mixer
 Synthesizer
 VCO
 VCO dividers and LO chain
RF Mixer
The high linearity SKY73208-11 integrates an active, double
balanced mixer that provides good noise performance and an
excellent third order input intercept point (IIP3).
The balanced nature of the mixer also provides for high port-to-
port isolation. A wideband match to 50 Ω is provided internally,
which eliminates the need for any external matching components
except for a coupling capacitor.
The IF outputs are designed for a 200 Ω differential impedance
and require off-chip matching.
Synthesizer
The frequency synthesizer is composed of the R-divider, N-
divider, phase detector, charge pump, and lock detector.
R-Divider
The 11-bit programmable R-divider divides the reference input
frequency and generates the reference input for the phase
detector. The R-divider range varies from 1 to 2¹¹ –1 (= 2047).
N-Divider
The N-divider consists of a selectable 16/17 or 32/33 prescaler,
13-bit main counter, and 5-bit swallow counter. The 18-bit N-
divider ratio is calculated as:
N=P×M+S
Where: P = Prescaler value
M = Main counter value
S = Swallow counter value
The N-divider range is from P² to 2¹⁸ – 1. For a 32/33 prescaler,
the N-divider range varies from 1024 to 262143.
Phase Detector
The phase detector is an edge-controlled digital circuit. The
circuit has two inputs: the reference signal (Ref) and the N-divider
output. There are two digital outputs (Up and Dn) that drive the
charge pump.
When the input phase difference is positive, the Up output is
pulled up to VDD. When the input phase difference is negative,
the Dn output is pulled down to ground. This type of phase
detector acts only on the positive edges of the input signals.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
201317F • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • November 5, 2015
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