SKY65045-70LF Datasheet, PDF (15/22 Pages) Skyworks Solutions Inc. – 390 - 1500 MHz Low Noise Power Amplifier Driver

Data Sheet • SKY65045-70LF
Typical Performance Data
V_CC = 5 V, F = 897.5 MHz, CW, Z_o = 50 Ω, T_c = 25 °C, unless otherwise noted
-40 °C
1.30
+25 °C
+85 °C
-40 °C
60
+25 °C
+85 °C
1.25
55
1.20
50
1.15
45
1.10
40
1.05
35
1.00
4.5
5.0
5.5
V_CC (V)
Gain Flatness vs. V_CC across temperature
30
4.5
5.0
5.5
V_CC (V)
Quiescent Current vs. V_CC across temperature
Theory of Operation
The SKY65045-70LF is a single stage, low noise power amplifier
in a low-cost surface mount package. The device operates with
a single 5 V power supply connected though an RF choke (L1) to
the output pin. Capacitors C7, C8 and C9 provide DC bias decou-
pling for V_CC. The bias current is set by the on-chip active bias
composed of current mirror and reference voltage transistors,
allowing for excellent gain tracking over temperature and voltage
variations. The part is externally RF matched using surface mount
components to facilitate operation over a frequency range of
390 to 1500 MHz.
Pin 1 is the RF input and Pin 3 is the RF output. External DC
blocking is required on the input and output, but can be imple-
mented as part of the RF matching circuit. Pin 2 and the package
backside metal, Pin 4, provide the DC and RF ground.
Application Circuit Notes
RF In (Pin 1). Amplifier RF input pin. The amplifier requires a DC
blocking capacitor as part of the external RF matching.
Ground (Pin 2). Attach the ground pin to the RF ground plane
with the largest diameter and lowest inductance via that the
layout will allow. Multiple small vias are also acceptable and will
work well under the device if solder migration is an issue.
RF Out/V_CC (Pin 3). Amplifier RF output pin. The amplifier
requires a DC blocking capacitor as part of the external RF
matching. The amplifier collector supply voltage is supplied
through an RF choke to the output at pin 3.
Center Ground (Pin 4). It is extremely important that the device
paddle be sufficiently grounded for both thermal and stability rea-
sons. Multiple small vias are acceptable and will work well under
the device if solder migration is an issue.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
200960 Rev. E • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • December 3, 2008
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