ETC GSM850

RF3140
0
QUAD-BAND GSM850/GSM900/DCS/PCS
POWER AMP MODULE
Typical Applications
• Portable Battery-Powered Equipment
• Power StarTM Module
0.400 TYP
Product Description
The RF3140 is a high-power, high-efficiency power amplifier module with integrated power control. The device is
self-contained with 50Ω input and output terminals. The
power control function is also incorporated, eliminating
the need for directional couplers, detector diodes, power
control ASICs and other power control circuitry; this
allows the module to be driven directly from the DAC output. The device is designed for use as the final RF amplifier in GSM850, EGSM900, DCS and PCS handheld
digital cellular equipment and other applications in the
824MHz to 849MHz, 880MHz to 915MHz, 1710MHz to
1785MHz and 1850MHz to 1910MHz bands. On-board
power control provides over 50dB of control range with an
analog voltage input; and, power down with a logic “low”
for standby operation.
9.600 TYP
8.800 TYP
8.200 TYP
7.400 TYP
6.800 TYP
6.000 TYP
5.400 TYP
4.600 TYP
4.000 TYP
3.200 TYP
2.600 TYP
1.800 TYP
1.200 TYP
0.400 TYP
0.000
Pin 1
8.747
5.925
4.075
9
Si BJT
GaAs HBT
Si Bi-CMOS
SiGe HBT
InGaP/HBT
GaN HEMT
8.280
8.205
9.098 TYP
1.797
0.000
1.245
0.306
1.70
1.45
Pin 1
10.00
± 0.10
10.00 ± 0.10
Optimum Technology Matching® Applied
5.400 TYP
6.000 TYP
6.800 TYP
7.400 TYP
8.200 TYP
8.275 TYP
8.800 TYP
9.600 TYP
• GPRS Class 12 Compatible
3.200 TYP
4.000 TYP
4.600 TYP
• Commercial and Consumer Systems
2.600 TYP
• GSM850/EGSM900/DCS/PCS Products
1.200 TYP
1.800 TYP
• 3V Quad-Band GSM Handsets
0.450
± 0.075
Package Style: Module (10mmx10mm)
GaAs MESFET
9Si CMOS
Features
SiGe Bi-CMOS
• Complete Power Control Solution
• Single 3.0V to 5.5V Supply Voltage
VCC2
• +35dBm GSM Output Power at 3.5V
• +33dBm DCS/PCS Output Power at 3.5V
12
DCS/PCS IN 1
11 DCS/PCS OUT
• 60% GSM and 55% DCS/PCS ηEFF
BAND SELECT 2
• 10mmx10mm Package Size
TX ENABLE 3
10 VCC OUT
VBATT 4
VREG 5
Ordering Information
VRAMP 6
9 GSM850/GSM900 OUT
GSM850/GSM900 IN 7
RF3140
VCC2
8
Functional Block Diagram
Rev A6 040113
RF3140
RF3140 PCBA
Quad-Band GSM850/GSM900/DCS/PCS Power
Amp Module
Power Amp Module 5-Piece Sample Pack
Fully Assembled Evaluation Board
RF Micro Devices, Inc.
7628 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
2-491
RF3140
Absolute Maximum Ratings
Parameter
Supply Voltage
Power Control Voltage (VRAMP)
Input RF Power
Max Duty Cycle
Output Load VSWR
Operating Case Temperature
Storage Temperature
Parameter
Rating
Unit
-0.3 to +6.0
-0.3 to +1.8
+8.5
50
10:1
-20 to +85
-55 to +150
VDC
V
dBm
%
°C
°C
Specification
Min.
Typ.
Max.
Caution! ESD sensitive device.
RF Micro Devices believes the furnished information is correct and accurate
at the time of this printing. However, RF Micro Devices reserves the right to
make changes to its products without notice. RF Micro Devices does not
assume responsibility for the use of the described product(s).
Unit
Condition
Overall Power Control
VRAMP
Power Control “ON”
Power Control “OFF”
VRAMP Input Capacitance
VRAMP Input Current
Turn On/Off Time
0.2
15
1.5
0.25
20
10
2
V
V
pF
µA
µs
Max. POUT, Voltage supplied to the input
Min. POUT, Voltage supplied to the input
DC to 2MHz
VRAMP =VRAMP MAX
VRAMP =0.2V to VRAMP MAX
5.5
10
V
V
µA
Specifications
Nominal operating limits
PIN <-30dBm, TX Enable=Low,
Temp=-20°C to +85°C
VRAMP =0.2V, TX Enable=High
Overall Power Supply
Power Supply Voltage
3.5
3.0
Power Supply Current
VREG Voltage
VREG Current
1
2.7
2.8
7
10
150
2.9
8
mA
V
mA
µA
0.5
3.0
50
0.5
3.0
2
V
V
µA
V
V
µA
TX Enable=High
TX Enable=Low
Overall Control Signals
Band Select “Low”
Band Select “High”
Band Select “High” Current
TX Enable “Low”
TX Enable “High”
TX Enable “High” Current
2-492
0
1.9
0
1.9
0
2.0
20
0
2.0
1
Rev A6 040113
RF3140
Parameter
Specification
Min.
Typ.
Max.
Unit
Temp=+25 °C, VBATT =3.5V,
VRAMP =VRAMP MAX, PIN =3dBm,
VREG =2.8V, Freq=824MHz to 849MHz,
25% Duty Cycle, Pulse Width=1154µs
Overall (GSM850 Mode)
Operating Frequency Range
Maximum Output Power
+34.2
824 to 849
+35.0
MHz
dBm
32
33
dBm
45
0
55
+3
+5
%
dBm
Output Noise Power
-86
-84
dBm
Forward Isolation 1
Forward Isolation 2
Cross Band Isolation at 2f0
Second Harmonic
Third Harmonic
All Other
Non-Harmonic Spurious
Input Impedance
Input VSWR
Output Load VSWR Stability
Output Load VSWR Ruggedness
-35
-25
-30
-15
-30
-25
-10
-20
-5
-10
-36
dBm
dBm
dBm
dBm
dBm
dBm
Total Efficiency
Input Power Range
Condition
Ω
50
50
Ω
VRAMP =0.2V to VRAMP MAX
Spurious<-36dBm, RBW=3MHz
Set VRAMP where VRAMP <34.2dBm into
50Ω load
Load impedance presented at RF OUT pad
55
dB
VRAMP =0.2V to VRAMP MAX
2.5:1
8:1
10:1
Output Load Impedance
Temp = 25°C, VBATT =3.5V,
VRAMP =VRAMP MAX
Temp=+85 °C, VBATT =3.0V,
VRAMP =VRAMP MAX
At POUT MAX, VBATT =3.5V
Maximum output power guaranteed at minimum drive level
RBW=100kHz, 869MHz to 894MHz,
POUT > +5dBm
TXEnable=Low, 0V, PIN =+5dBm
TXEnable=High, PIN =+5dBm, VRAMP =0.2V
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
Power Control VRAMP
Power Control Range
Note: VRAMP MAX =3/8*VBATT +0.18<1.5V
Rev A6 040113
2-493
RF3140
Parameter
Specification
Min.
Typ.
Max.
Unit
Temp=+25 °C, VBATT =3.5V,
VRAMP =VRAMP MAX, PIN =3dBm,
VREG =2.8V, Freq=880MHz to 915MHz,
25% Duty Cycle, Pulse Width=1154µs
Overall (GSM900 Mode)
Operating Frequency Range
Maximum Output Power
Total Efficiency
Input Power Range
+34.2
880 to 915
+35.0
MHz
dBm
32
33
dBm
52
0
58
+3
+5
%
dBm
-86
-82
dBm
-88
-84
dBm
-35
-25
-24
-15
-30
-25
-10
-20
-5
-10
-36
dBm
dBm
dBm
dBm
dBm
dBm
Output Noise Power
Forward Isolation 1
Forward Isolation 2
Cross Band Isolation 2f0
Second Harmonic
Third Harmonic
All Other
Non-Harmonic Spurious
Input Impedance
Input VSWR
Output Load VSWR Stability
Output Load VSWR Ruggedness
Condition
Ω
50
50
Ω
VRAMP =0.2V to VRAMP MAX
Spurious<-36dBm, RBW=3MHz
Set VRAMP where VRAMP <34.2dBm into
50Ω load
Load impedance presented at RF OUT pad
50
dB
VRAMP =0.2V to VRAMP MAX
2.5:1
8:1
10:1
Output Load Impedance
Temp = 25°C, VBATT =3.5V,
VRAMP =VRAMP MAX
Temp=+85 °C, VBATT =3.0V,
VRAMP =VRAMP MAX
At POUT MAX, VBATT =3.5V
Maximum output power guaranteed at minimum drive level
RBW=100kHz, 925MHz to 935MHz,
POUT > +5dBm
RBW=100kHz, 935MHz to 960MHz,
POUT > +5dBm
TXEnable=Low, 0V, PIN =+5dBm
TXEnable=High, VRAMP =0.2V, PIN =+5dBm
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
Power Control VRAMP
Power Control Range
Note: VRAMP MAX =3/8*VBATT +0.18<1.5V
2-494
Rev A6 040113
RF3140
Parameter
Specification
Min.
Typ.
Max.
Unit
Temp=25°C, VBATT =3.5V,
VRAMP =VRAMP MAX, PIN =3dBm,
VREG =2.8V, Freq=1710MHz to 1785MHz,
25% Duty Cycle, pulse width=1154µs
Overall (DCS Mode)
Operating Frequency Range
Maximum Output Power
+32
1710 to 1785
+33
MHz
dBm
+29.5
+31.0
dBm
48
0
55
+3
+5
%
dBm
Output Noise Power
-85
-80
dBm
Forward Isolation 1
Forward Isolation 2
-40
-20
-30
-10
dBm
dBm
Second Harmonic
Third Harmonic
All Other
Non-Harmonic Spurious
Input Impedance
Input VSWR
Output Load VSWR Stability
Output Load VSWR Ruggedness
-15
-30
-7
-15
-36
dBm
dBm
dBm
Total Efficiency
Input Power Range
Condition
50
-
Ω
50
Ω
VRAMP =0.2V to VRAMP MAX
Spurious<-36dBm, RBW=3MHz
Set VRAMP where VRAMP <34.2dBm into
50Ω load
Load impedance presented at RF OUT pin
50
dB
VRAMP =0.2V to VRAMP MAX, PIN =+5dBm
2.5:1
8:1
10:1
Output Load Impedance
Temp=25°C, VBATT =3.5V,
VRAMP =VRAMP MAX
Temp=+85°C, VBATT =3.0V,
VRAMP =VRAMP MAX
At POUT MAX, VBATT =3.5V
Maximum output power guaranteed at minimum drive level
RBW=100kHz, 1805MHz to 1880MHz,
POUT > 0dBm, VBATT =3.5V
TXEnable=Low, 0V, PIN =+5dBm
TXEnable=High, VRAMP =0.2V, PIN =0dBm
to +5dBm
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
Power Control VRAMP
Power Control Range
Note: VRAMP MAX =3/8*VBATT +0.18<1.5V
Rev A6 040113
2-495
RF3140
Parameter
Specification
Min.
Typ.
Max.
Unit
Temp=25°C, VBATT =3.5V,
VRAMP =VRAMP MAX, PIN =3dBm,
VREG =2.8V, Freq=1850MHz to 1910MHz,
25% Duty Cycle, pulse width=1154µs
Overall (PCS Mode)
Operating Frequency Range
Maximum Output Power
+32
1850 to 1910
+33
MHz
dBm
+29.5
+31.0
dBm
45
0
52
+3
+5
%
dBm
Output Noise Power
-85
-80
dBm
Forward Isolation 1
Forward Isolation 2
Second Harmonic
Third Harmonic
All Other
Non-Harmonic Spurious
Input Impedance
Input VSWR
Output Load VSWR Stability
-40
-20
-15
-30
-30
-10
-7
-15
-36
dBm
dBm
dBm
dBm
dBm
8:1
Output Load VSWR Ruggedness
10:1
Total Efficiency
Input Power Range
Condition
50
-
Output Load Impedance
Temp=25°C, VBATT =3.5V,
VRAMP =VRAMP MAX, 1850MHz to 1910MHz
Temp=+85°C, VBATT =3.0V,
VRAMP =VRAMP MAX
At POUT MAX, VBATT =3.5V
Full output power guaranteed at minimum
drive level
RBW=100kHz, 1930MHz to 1990MHz,
POUT > 0dBm, VBATT =3.5V
TX_ENABLE=Low, PIN =+5dBm
TXEnable=High, VRAMP =0.2V, PIN =+5dBm
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
VRAMP =0.2V to VRAMP MAX
Ω
50
Ω
VRAMP =0.2V to VRAMP MAX
Spurious<-36dBm, VRAMP =0.2V to
VRAMP MAX, RBW=3MHz
Set VRAMP where VRAMP <34.2dBm into
50Ω load
Load impedance presented at RF OUT pin
50
dB
VRAMP =0.2V to VRAMP MAX, PIN =+5dBm
2.5:1
Power Control VRAMP
Power Control Range
Note: VRAMP MAX =3/8*VBATT +0.18<1.5V
2-496
Rev A6 040113
RF3140
Pin
1
2
Function Description
DCS/PCS IN RF input to the DCS/PCS band. This is a 50Ω input.
Allows external control to select the GSM or DCS/PCS bands with a
BAND
logic high or low. A logic low enables the GSM bands, whereas a logic
SELECT
high enables the DCS/PCS bands.
3
TX ENABLE
4
5
6
VBATT
VREG
VRAMP
7
GSM850/GS
M900 IN
VCC2
8
9
10
11
12
Pkg
Base
GSM850/GS
M900 OUT
VCC OUT
DCS/PCS
OUT
VCC2
Interface Schematic
This signal enables the PA module for operation with a logic high. Once
TX Enable is asserted the RF output level will increase to -20dBm.
Power supply for the module. This should be connected to the battery.
Regulated voltage input for power control function. (2.8V nom)
Ramping signal from DAC. A simple RC filter may need to be connected between the DAC output and the VRAMP input depending on the
baseband selected.
RF input to the GSM bands. This is a 50Ω input.
Controlled voltage input to driver stage for GSM bands. This voltage is
part of the power control function for the module. This node must be
connected to VCC out.
RF output for the GSM bands. This is a 50Ω output. The output load
line matching is contained internal to the package.
Controlled voltage output to feed VCC2. This voltage is part of the power
control function for the module. It cannot be connected to anything
other than VCC2, nor can any component be placed on this node (i.e.,
decoupling capacitor).
RF output for the DCS/PCS bands. This is a 50Ω output. The output
load line matching is contained internal to the package.
Controlled voltage input to DCS/PCS driver stage. This voltage is part
of the power control function for the module. This node must be connected to VCC out.
GND
Rev A6 040113
2-497
RF3140
PIN #1
VCC2
Pin Out
DCS/PCS OUT
DCS/PCS IN
BAND SELECT
TX EN
VBATT
VCC OUT
10.0000
VREG
VRAMP
GSM850/GSM900 OUT
VCC2
GSM850/GSM900 IN
10.0000
2-498
Rev A6 040113
RF3140
Theory of Operation
Overview
The RF3140 is a quad-band GSM850, EGSM900,
DCS1800, and PCS1900 power amplifier module that
incorporates an indirect closed loop method of power
control. This simplifies the phone design by eliminating
the need for the complicated control loop design. The
indirect closed loop appears as an open loop to the
user and can be driven directly from the DAC output in
the baseband circuit.
Theory of Operation
The indirect closed loop is essentially a closed loop
method of power control that is invisible to the user.
Most power control systems in GSM sense either forward power or collector/drain current. The RF3140
does not use a power detector. A high-speed control
loop is incorporated to regulate the collector voltage of
the amplifier while the stage are held at a constant
bias. The VRAMP signal is multiplied by a factor of 2.65
and the collector voltage for the second and third
stages are regulated to the multiplied VRAMP voltage.
The basic circuit is shown in the following diagram.
VBATT
TX ENABLE
VRAMP
H(s)
RF IN
RF OUT
TX ENABLE
By regulating the power, the stages are held in saturation across all power levels. As the required output
power is decreased from full power down to 0dBm, the
collector voltage is also decreased. This regulation of
output power is demonstrated in Equation 1 where the
relationship between collector voltage and output
power is shown. Although load impedance affects output power, supply fluctuations are the dominate mode
of power variations. With the RF3140 regulating collector voltage, the dominant mode of power fluctuations is
eliminated.
2
( 2 ⋅ V CC – V SAT )
P dBm = 10 ⋅ log ------------------------------------------(Eq. 1)
–3
8 ⋅ R LOAD ⋅ 10
Rev A6 040113
There are several key factors to consider in the implementation of a transmitter solution for a mobile phone.
Some of them are:
•
Effective efficiency (ηeff)
•
Current draw and system efficiency
•
Power variation due to Supply Voltage
•
Power variation due to frequency
•
Power variation due to temperature
•
Input impedance variation
•
Noise power
•
Loop stability
•
Loop bandwidth variations across power levels
•
Burst timing and transient spectrum trade offs
•
Harmonics
Talk time and power management are key concerns in
transmitter design since the power amplifier has the
highest current draw in a mobile terminal. Considering
only the power amplifier’s efficiency does not provide a
true picture for the total system efficiency. It is important to consider effective efficiency which is represented by ηEFF. (ηEFF considers the loss between the
PA and antenna and is a more accurate measurement
to determine how much current will be drawn in the
application). ηEFF is defined by the following relationship (Equation 2):
m
∑ PN – PIN
=1
⋅ 100 (Eq. 2)
η EFF = n-------------------------------P DC
Where Pn is the sum of all positive and negative RF
power, PIN the input power and PDC is the delivered
DC power. In dB the formula becomes (Equation 3):
P PA + P LOSS
-----------------------------10
P IN
------10
10
– 10
η EFF = ------------------------------------------------- (Eq. 3)
V BAT ⋅ I BAT ⋅ 10
2-499
RF3140
Where PPA is the output power from the PA, PLOSS the
insertion loss, PIN the input power to the PA and PDC
the delivered DC power.
The RF3140 improves the effective efficiency by minimizing the PLOSS term in the equation. A directional
coupler may introduce 0.4dB to 0.5dB loss to the transit path. To demonstrate the improvement in effective
efficiency consider the following example:
Conventional PA Solution at F=1785MHz:
PPA = +33.5 dBm
PIN = +3 dBm
PLOSS = -0.4 dB
VBAT = 3.5 V
IBAT = 1.16 A
ηEFF = 50.3%
RF3140 Solution:
PPA = +33.5 dBm
PIN = +3 dBm
PLOSS = 0 dB
VBAT = 3.5 V
IBAT = 1.16 A
hEFF = 55.16%
The RF3140 solution improves effective efficiency by
5%.
Output power does not vary due to supply voltage
under normal operating conditions if VRAMP is sufficiently lower than VBATT. By regulating the collector
voltage to the PA the voltage sensitivity is essentially
eliminated. This covers most cases where the PA will
be operated. However, as the battery discharges and
approaches its lower power range the maximum output
power from the PA will also drop slightly. In this case it
is important to also decrease VRAMP to prevent the
power control from inducing switching transients.
These transients occur as a result of the control loop
slowing down and not regulating power in accordance
with VRAMP.
The switching transients due to low battery conditions
are regulated by incorporating the following relationship limiting the maximum VRAMP voltage (Equation 2).
Although no compensation is required for typical battery conditions, the battery compensation required for
extreme conditions is covered by the relationship in
Equation 4. This should be added to the terminal software.
2-500
3
V RAMP ≤ --- ⋅ V CC + 0.18 (Eq. 4)
8
Due to reactive output matches, there are output power
variations across frequency. There are a number of
components that can make the effects greater or less.
Power variation straight out of the RF3140 is shown in
the tables below.
The components following the power amplifier often
have insertion loss variation with respect to frequency.
Usually, there is some length of microstrip that follows
the power amplifier. There is also a frequency
response found in directional couplers due to variation
in the coupling factor over frequency, as well as the
sensitivity of the detector diode. Since the RF3140
does not use a directional coupler with a diode detector, these variations do not occur.
Input impedance variation is found in most GSM power
amplifiers. This is due to a device phenomena where
CBE and CCB (CGS and CSG for a FET) vary over the
bias voltage. The same principle used to make varactors is present in the power amplifiers. The junction
capacitance is a function of the bias across the junction. This produces input impedance variations as the
Vapc voltage is swept. Although this could present a
problem with frequency pulling the transmit VCO off
frequency, most synthesizer designers use very wide
loop bandwidths to quickly compensate for frequency
variations due to the load variations presented to the
VCO.
The RF3140 presents a very constant load to the VCO.
This is because all stages of the RF3140 are run at
constant bias. As a result, there is constant reactance
at the base emitter and base collector junction of the
input stage to the power amplifier.
Noise power in PA's where output power is controlled
by changing the bias voltage is often a problem when
backing off of output power. The reason is that the gain
is changed in all stages and according to the noise formula (Equation 5),
F2 – 1 F3 – 1
F TOT = F1 + ---------------- + ------------------- (Eq. 5)
G1
G1 ⋅ G2
the noise figure depends on noise factor and gain in all
stages. Because the bias point of the RF3140 is kept
constant the gain in the first stage is always high and
the overall noise power is not increased when decreasing output power.
Rev A6 040113
RF3140
Power control loop stability often presents many challenges to transmitter design. Designing a proper power
control loop involves trade-offs affecting stability, transient spectrum and burst timing.
In conventional architectures the PA gain (dB/ V) varies
across different power levels, and as a result the loop
bandwidth also varies. With some power amplifiers it is
possible for the PA gain (control slope) to change from
100dB/V to as high as 1000dB/V. The challenge in this
scenario is keeping the loop bandwidth wide enough to
meet the burst mask at low slope regions which often
causes instability at high slope regions.
The RF3140 loop bandwidth is determined by internal
bandwidth and the RF output load and does not
change with respect to power levels. This makes it easier to maintain loop stability with a high bandwidth loop
since the bias voltage and collector voltage do not vary.
An often overlooked problem in PA control loops is that
a delay not only decreases loop stability it also affects
the burst timing when, for instance the input power
from the VCO decreases (or increases) with respect to
temperature or supply voltage. The burst timing then
appears to shift to the right especially at low power levels. The RF3140 is insensitive to a change in input
power and the burst timing is constant and requires no
software compensation.
Switching transients occur when the up and down
ramp of the burst is not smooth enough or suddenly
changes shape. If the control slope of a PA has an
inflection point within the output power range or if the
slope is simply too steep it is difficult to prevent switching transients. Controlling the output power by changing the collector voltage is as earlier described based
on the physical relationship between voltage swing and
output power. Furthermore all stages are kept constantly biased so inflection points are nonexistent.
Rev A6 040113
Harmonics are natural products of high efficiency
power amplifier design. An ideal class “E” saturated
power amplifier will produce a perfect square wave.
Looking at the Fourier transform of a square wave
reveals high harmonic content. Although this is common to all power amplifiers, there are other factors that
contribute to conducted harmonic content as well. With
most power control methods a peak power diode
detector is used to rectify and sense forward power.
Through the rectification process there is additional
squaring of the waveform resulting in higher harmonics. The RF3140 address this by eliminating the need
for the detector diode. Therefore the harmonics coming
out of the PA should represent the maximum power of
the harmonics throughout the transmit chain. This is
based upon proper harmonic termination of the transmit port. The receive port termination on the T/R switch
as well as the harmonic impedance from the switch
itself will have an impact on harmonics. Should a problem arise, these terminations should be explored.
The RF3140 incorporates many circuits that had previously been required external to the power amplifier.
The shaded area of the diagram below illustrates those
components and the following table itemizes a comparison between the RF3140 Bill of Materials and a conventional solution:
Component
Power Control ASIC
Directional Coupler
Buffer
Attenuator
Various Passives
Mounting Yield
(other than PA)
Total
Conventional
Solution
$0.80
$0.20
$0.05
$0.05
$0.05
$0.12
RF3140
$1.27
$0.00
N/A
N/A
N/A
N/A
N/A
N/A
2-501
RF3140
1
14
2
13
3
12
4
11
5
10
6
9
7
8
From DAC
*Shaded area eliminated with Indirect Closed Loop using RF3140
2-502
Rev A6 040113
RF3140
Application Schematic
12
50 Ω µstrip
DCS/PCS IN
1
BAND SELECT
2
TX ENABLE
3
VBATT
4
VREG
50 Ω µstrip
11
DCS/PCS OUT
10
5
15 kΩ**
VRAMP
6
50 Ω µstrip
GSM850/GSM900 IN
50 Ω µstrip
7
9
GSM850/GSM900 OUT
8
** Used to filter noise and spurious from base band.
Evaluation Board Schematic
(Download Bill of Materials from www.rfmd.com.)
P1
1
GND
CON1
P2-1
P2
1
VCC
CON1
50 Ω µstrip
DCS/PCS IN
12
6.8 pF
1
BAND SELECT
3
VBATT
10
4
VRAMP
DCS/PCS OUT
2
TX ENABLE
VREG
50 Ω µstrip
11
22 µF*
1 nF*
50 Ω µstrip
5
15 kΩ**
6
50 Ω µstrip
7
GSM850/GSM900 IN
9
GSM850/GSM900 OUT
8
*Not required in most applications.
** Used to filter noise and spurious from base band.
Note 1: All the PA output measurements are referenced to the PA output pad (Pin 11 and 9).
Note 2: The 50 Ω microstrip between the PA output pad and the SMA connector has an
approximate insertion loss of 0.1 dB for GSM850/EGSM900 and 0.2 dB for
DCS1800/PCS1900 bands.
Rev A6 040113
2-503
RF3140
Evaluation Board Layout
Board Size 2.0” x 2.0”
Board Thickness 0.032”, Board Material FR-4, Multi-Layer
2-504
Rev A6 040113
RF3140
PCB Design Requirements
PCB Surface Finish
The PCB surface finish used for RFMD’s qualification process is electroless nickel, immersion gold. Typical thickness is
3µinch to 8µinch gold over 180µinch nickel.
PCB Land Pattern Recommendation
PCB land patterns are based on IPC-SM-782 standards when possible. The pad pattern shown has been developed and
tested for optimized assembly at RFMD; however, it may require some modifications to address company specific
assembly processes. The PCB land pattern has been developed to accommodate lead and package tolerances.
PCB Metal Land and Solder Mask Pattern
A = 0.80 (mm) Sq. Typ.
B = 2.17 x 6.40 (mm)
A = 0.80 (mm) Sq. Typ.
A
4.20 (mm) Typ.
A
2.81 (mm)
A
1.40 (mm)
A
0.00
A
A
A
3.30 (mm)
3.21 (mm)
2.41 (mm)
1.78 (mm)
0.98 (mm)
0.89 (mm) Typ.
A
A
A
A
A
A
A
A
A
A
A
4.20 (mm) Typ.
A
A
A
A
A
2.81 (mm) Typ.
A
A
A
A
A
1.40 (mm) Typ.
A
A
A
A
A
0.00
A
A
A
A
A
A
A
8.39 (mm) Typ.
5.60 (mm)
A
7.00 (mm) Typ.
A
A
A
7.00 (mm) Typ.
A
5.60 (mm) Typ.
8.39 (mm) Typ.
A
7.51 (mm) Typ.
Pin 1
5.60 (mm) Typ.
7.00 (mm)
1.40 (mm) Typ.
7.49 (mm) Typ.
6.60 (mm)
6.00 (mm)
5.20 (mm)
5.11 (mm)
2.79 (mm) Typ.
3.48 (mm)
4.19 (mm) Typ.
8.39 (mm) Typ.
A
1.40 (mm) Typ.
A
2.30 (mm) Typ.
A
Metal Land Pattern
0.00
Pin 1
0.00
8.39 (mm) Typ.
A
A
B
4.20 (mm)
Solder Mask Pattern
Figure 1. PCB Metal Land and Solder Mask Pattern (Top View)
Rev A6 040113
2-505
RF3140
Thermal Pad and Via Design
The PCB land pattern has been designed with a thermal pad that matches the exposed die paddle size on the bottom of
the device.
Thermal vias are required in the PCB layout to effectively conduct heat away from the package. The via pattern shown
has been designed to address thermal, power dissipation and electrical requirements of the device as well as accommodating routing strategies.
The via pattern used for the RFMD qualification is based on thru-hole vias with 0.203mm to 0.330mm finished hole size
with 0.025mm plating on via walls. If micro vias are used in a design, it is suggested that the quantity of vias be
increased by a 4:1 ratio to achieve similar results. .
1.40 (mm) Grid
Figure 2. Thermal Pad and Via Design (RFMD qualification)
2-506
Rev A6 040113