April 14, 2011 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 201121G
DATA SHEET • SKY73078-459LF
QUADRATURE MODULATOR
Technical Description
The SKY73078-459LF is comprised of four main functional areas:
the LO chain, the baseband input level shifters, the mixers, and
the differential to single-ended converter.
LO Chain
The LO chain consists of an input linear buffer, a polyphase
quadrature phase splitter, and limiting amplifiers. The input buffer
provides an internal 50
Ω
match while generating an amplified
differential signal to the polyphase splitters.
The LO can be driven either single-ended or differentially. For
single-ended LO signals, the LON signal (pin 9) should be AC-
grounded using a capacitor. Each quadrature LO signal is passed
through limiting amplifiers before driving the mixers.
Baseband Input Level Shifters
The baseband inputs present a high input impedance while
providing proper DC levels for the mixer inputs. The recommended
DC voltage for the baseband common-mode voltage is 500 mV.
Mixers
The SKY73078-459LF incorporates two Gilbert-type, double-
balanced mixers for both the In-Phase (I) and Quadrature (Q)
channels. The differential output currents are summed together
into an on-chip passive balun, which converts the differential
signal to a single-ended output.
Differential to Single-Ended Converter
The differential to single-ended converter is an on-chip passive
balun that converts the differential mixer output signal to a single-
ended signal. The high impedance output of the balun is designed
to interface directly to a 50
Ω
load. If desired, an external
matching network could be used for power matching between the
balun and the 50
Ω
load.
Electrical and Mechanical Specifications
The absolute maximum ratings of the SKY73078-459LF are
provided in Table 2. The recommended operating conditions are
specified in Table 3 and electrical specifications are provided in
Tables 4, 5, and 6.
Table 2. SKY73078-459LF Absolute Maximum Ratings
Parameter
Supply voltage, +5 V
Supply current
LO input power
Operating temperature
Junction temperature
Storage temperature
VCC
I
CC
P
LO
T
C
T
J
T
STG
–40
–40
Symbol
Minimum
4.75
Typical
Maximum
5.50
218
+6
+85
+150
+125
Units
V
mA
dBm
°C
°C
°C
Notes:
Exposure to maximum rating conditions for extended periods may reduce device reliability. There is no damage to device with only one parameter set at the limit and all other
parameters set at or below their nominal value. Exceeding any of the limits listed here may result in permanent damage to the device.
Nominal thermal resistance (junction to case) is 5.1 °C/W.
CAUTION:
Although this device is designed to be as robust as possible, Electrostatic Discharge (ESD) can damage this device. This device
must be protected at all times from ESD. Static charges may easily produce potentials of several kilovolts on the human body
or equipment, which can discharge without detection. Industry-standard ESD precautions should be used at all times. The
SKY73078-459LF ESD threshold level is 2500 VDC using Human Body Model (HBM) testing. This level applies to RF signal lines
>100 MHz, analog and RF lines <100 MHz, digital lines, power supply lines, and ground pins.
LO Amplitude = 0 dBm, I/Q Amplitude = 1.4 Vpp differential, V
CM
= 0.5 V, F
BB
= 1 MHz, Unless Otherwise Noted)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
GSM850 and EGSM900, F
RF
= 869 MHz to 960 MHz
RF output power (Note 2)
1 dB Output Compression Point
Carrier feedthrough
Sideband suppression
2nd harmonic (harmonic of baseband input)
2fo
P
OUT
= +7.5 dBm,
harmonic output @ F
LO
±
2F
BB
P
OUT
= +7.5 dBm,
harmonic output @ F
LO
±
3F
BB
P
OUT
OP1dB
+6
+10.5
–43
–48
–63
dBm
dBm
dBm
dBc
dBc
3rd harmonic (harmonic of baseband input)
3fo
–49
dBc
3rd Order Output Intercept Point
Noise floor:
without I/Q inputs
with I/Q inputs
Output return loss
OIP3
@ 20 MHz, I/Q = 0 V
DIFF
@ 6 MHz, P
OUT
= +5 dBm
+27
–158.6
–153.5
TBD
dBm
dBm/Hz
dBm/Hz
dB
LTE Bands XII and XIII, F
RF
= 728 MHz to 756 MHz
RF output power (Note 3)
1 dB Output Compression Point
Carrier feedthrough
Sideband suppression
2nd harmonic (harmonic of baseband input)
2fo
P
OUT
= +4 dBm,
harmonic output @
F
LO
± 2Fbb
P
OUT
= +4 dBm,
harmonic output @
F
LO
± 3Fbb
P
OUT
OP1dB
+4
+8
–45
–57
–68
dBm
dBm
dBm
dBc
dBc
3rd harmonic (harmonic of baseband input)
3fo
–49
dBc
3rd Order Output Intercept Point
Noise floor:
without I/Q inputs
with I/Q inputs
Output return loss
OIP3
@ 20 MHz, I/Q = 0 V
DIFF
@ 6 MHz, P
OUT
= +4 dBm
+25
–160.5
–152.0
TBD
dBm
dBm/Hz
dBm/Hz
dB
Note 1:
Performance is guaranteed only under the conditions listed in this Table.
Note 2:
While the device is specified to achieve +7.5 dBm RF output with sinusoidal baseband inputs, typical RF output power for normal GMSK operation is +4 dBm (single carrier power) or
–9.5 dBm (multicarrier total power).
Note
3:
While the device is specified to achieve +4 dBm RF output with sinusoidal baseband inputs, typical RF output power for normal LTE operation is TBD dBm total power.
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