AN219

BF P7 4 0 E SD
BF P7 4 0 E SD E S D- H a rd e n e d S i Ge :C
Ul tr a L o w No i s e R F Tra n s i s to r wi t h
2 k V ES D Ra ti n g i n 5 – 6 G Hz L NA
Ap p l i c a ti o n . 1 5 d B G a i n , 1 .3 d B No i s e
Fi g u r e & < 1 0 0 n s T u rn - O n / T u rn - O ff
Ti m e
Fo r 8 0 2 . 1 1 a & 8 0 2 . 1 1 n “ MI M O”
W i re l e s s L A N Ap p l i c a ti o n s
Ap p l i c a ti o n N o te A N 2 1 9
Revision: Rev. 1.0
2010-07-12
RF a n d P r o te c ti o n D e vi c e s
Edition 2010-07-12
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2010 Infineon Technologies AG
All Rights Reserved.
Legal Disclaimer
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BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Application Note AN219
Revision History: 2010-07-12
Previous Revision: prev. Rev.
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Subjects (major changes since last revision)
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MICROTEC™, NUCLEUS™ of Mentor Graphics Corporation. Mifare™ of NXP. MIPI™ of MIPI Alliance, Inc.
MIPS™ of MIPS Technologies, Inc., USA. muRata™ of MURATA MANUFACTURING CO. OmniVision™ of
OmniVision Technologies, Inc. Openwave™ Openwave Systems Inc. RED HAT™ Red Hat, Inc. RFMD™ RF
Micro Devices, Inc. SIRIUS™ of Sirius Sattelite Radio Inc. SOLARIS™ of Sun Microsystems, Inc. SPANSION™
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of Diodes Zetex Limited.
Last Trademarks Update 2009-10-19
Application Note AN219, Rev. 1.0
3 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
List of Content, Figures and Tables
Table of Content
1
Overview ............................................................................................................................................. 6
2
Typical Measurement Results........................................................................................................... 6
3
Schematic Diagram ............................................................................................................................ 7
4
Bill of Material ..................................................................................................................................... 8
5
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.9.1
5.9.2
Measured Graphs ............................................................................................................................... 9
Noise Figure ......................................................................................................................................... 9
1 dB Compression Point .................................................................................................................... 11
Gain .................................................................................................................................................... 12
Input Return Loss ............................................................................................................................... 13
Output Return Loss ............................................................................................................................ 15
Reverse Isolation................................................................................................................................ 17
Amplifier Stability ................................................................................................................................ 19
Third Order Intercept Point ................................................................................................................. 20
Turn-On / Turn-Off Time .................................................................................................................... 21
Turn On Time ..................................................................................................................................... 22
Turn Off Time ..................................................................................................................................... 23
6
Details of PC Board Construction .................................................................................................. 24
7
SOT343 Package Outline and Foot Print ....................................................................................... 26
8
ESD Protection ................................................................................................................................. 27
Authors
28
List of Figures
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Figure 20
Figure 21
Schematic Diagram .............................................................................................................................. 7
Noise Figure Plot, from Rohde and Schwarz FSEK3 + FSEM30 ........................................................ 9
Input 1 dB Compression Point ........................................................................................................... 11
Forward Gain...................................................................................................................................... 12
Input Return Loss in dB ...................................................................................................................... 13
Input Return Loss, Smith Chart .......................................................................................................... 14
Output Return Loss in dB ................................................................................................................... 15
Output Return Loss, Smith Chart ....................................................................................................... 16
Reverse Isolation................................................................................................................................ 17
Reverse Isolation, Amplifier DC Power turned off.............................................................................. 18
Definition of Stability Factor µ1 .......................................................................................................... 19
Stability Factor.................................................................................................................................... 19
Carrier and Intermodulation Products at LNA’s Output...................................................................... 20
Test setup for Turn-On / Turn-Off measurements ............................................................................. 21
Turn On Time ..................................................................................................................................... 22
Turn Off time ...................................................................................................................................... 23
View of entire PC Board, Top / Component Side............................................................................... 24
Close-In View of LNA Section ............................................................................................................ 24
Backside of PCB ................................................................................................................................ 25
PCB Layer Information ....................................................................................................................... 25
SOT344 package outline and recommended foot print ..................................................................... 26
Application Note AN219, Rev. 1.0
4 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
List of Content, Figures and Tables
List of Tables
Table 1
Table 2
Table 3
Electrical Characteristics (at room temperature).................................................................................. 6
Bill-of-Materials..................................................................................................................................... 8
Noise Figure, Tabular Data ................................................................................................................ 10
Application Note AN219, Rev. 1.0
5 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Overview
1
Overview
The BFP740FESD is a high gain, ultra low noise Silicon-Germanium-Carbon (SiGe:C) HBT device suitable for a
wide range of Low Noise Amplifier (LNA) applications. The BFP740FESD has internal ESD-protection
structures giving an ESD-survival rating of 2000 Volts per the Human Body Model (HBM), for ESD strikes of
either polarity applied across any pair of terminals (Base, Emitter, Collector).
The circuit shown in this document is targeted for 802.11a & 802.11n “MIMO” applications in the Wireless Local
Area Network (WLAN) market, particularly for Access Points (AP’s) which require external LNA’s to fulfill highsensitivity / long range requirements. LNA’s for this application must be able to switch on / off within about 1
microsecond (1000 nanoseconds). The charge storage (capacitance) used in the circuit is minimized to reduce
turn-on / turn-off times. Trade-off for reduced capacitance values is a reduction in Third Order Intercept (IP3)
performance. Amplifier is Unconditionally Stable (µ1 > 1.0) from 10 MHz – 12 GHz.
External parts count (not including BFP740 transistor) = 12; 6 capacitors, 3 resistors, and 3 chip inductors. All
passives are ‘0402’ case size. BFP740ESD transistor package is RoHS – compliant, industry-standard SOT343
type.
2
Typical Measurement Results
Table 1
Electrical Characteristics (at room temperature)
Parameter
Symbol
Value
Unit
Frequency
Freq
5.470
GHz
DC Voltage
Vcc
3.0
V
DC Current
Icc
14.7
mA
Gain
G
15.5
dB
Network analyzer source power = -25 dBm
Noise Figure
NF
1.3
dB
Does not extract PCB loss. If PCB loss at input
were extracted, NF would be ~0.2 dB lower
Input Return Loss
RLin
17.8
dB
Network analyzer source power = -25 dBm
Output Return Loss
RLout
23.9
dB
Network analyzer source power = -25 dBm
Reverse Isolation
IRev
20.3
dB
Network analyzer source power = -25 dBm
When DC Power to LNA is OFF: 14.8dB
Input P1dB
IP1dB
-6.4
dBm
Output P1dB
OP1dB
8.1
dBm
Input IP3
IIP3
7.2
dBm
Input power -23dBm / tone, ∆f = 1MHz
Output IP3
OIP3
22.7
dBm
Input power -23dBm / tone, ∆f = 1MHz
Application Note AN219, Rev. 1.0
6 / 29
Comment/Test Condition
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Schematic Diagram
3
Schematic Diagram
Figure 1
Schematic Diagram
Application Note AN219, Rev. 1.0
7 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Bill of Material
4
Bill of Material
Table 2
Bill-of-Materials
Symbol
Value
Unit
Size
Manufacturer
Comment
C1
0.3
pF
0402
Input matching
C2
1.0
pF
0402
Murata
GRM1555C1HR30BZ01D
or equivalent
various
Input DC block, input matching
C3
1.5
pF
0402
various
RF decoupling / blocking cap
C4
33
pF
0402
various
RF decoupling / blocking cap
C5
1.5
pF
0402
various
RF decoupling / blocking cap
C6
0.5
pF
0402
L1
6.8
nH
0402
L2
1.8
nH
0402
Murata LQP15M series
L3
1.3
nH
0402
Murata LQP15M series
R1
22
Ω
0402
various
RF Choke at LNA output, for DC bias
to collector. Also influences matching
and stability.
Output matching; also influences
input match.
For RF stability improvement
R2
27
kΩ
0402
various
DC biasing (base).
R3
39
Ω
0402
various
DC biasing (provides DC negative
feedback to stabilize DC operating
point over temperature variation,
transistor hFE variation, etc.)
TSFP-4
Infineon Technologies
LNA active device
Q1
BFP740ESD
Murata
Output DC block and output
GRM1555C1HR30BZ01D
matching. Also influences input
or equivalent
match.
Murata LQP15M series
RF Choke at LNA input (for DC bias
to base).
J1, J2
RF Edge Mount SMA Female
Connector,
142-0701-841
Emerson / Johnson
Input / Output RF connector
J3
MTA-100 Series 5 pin connector
640456-5
PC Board, Part # 740ESD100531 Rev A
Tyco (AMP)
5 Pin DC connector header
Infineon Technologies
Printed Circuit Board
---
Application Note AN219, Rev. 1.0
8 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5
Measured Graphs
The reference plane of all data displayed here are the input and output SMA connectors of the evaluation board.
This means all PCB losses and SMA connector losses are included.
5.1
Noise Figure
Rohde & Schwarz FSEK3
02 Jul 2010
Noise Figure Measurement
EUT Name:
Manufacturer:
Operating Conditions:
Operator Name:
Test Specification:
Comment:
AN219, BFP740ESD 5 - 6 GHz LNA, Fast Switching / Fast Turn ON-OFF time
Infineon Technologies
T=25 C, V = 3.0 Volts, Vce = 2.1 Volts, I = 14.7 mA
Gerard Wevers
WLAN 802.11n, 802.11a
PCB = 740ESD-100531 Rev A; Preamp = MITEQ AFS3-04000800-10-ULN
2 July 2010
Analyzer
RF Att:
Ref Lvl:
0.00 dB
-45.00 dBm
RBW :
VBW :
1 MHz
100 Hz
Range: 30.00 dB
Ref Lvl auto: ON
Measurement
2nd stage corr: ON
Mode: Direct
ENR: 346A173.ENR
Noise Figure /dB
1.90
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
1.00
0.90
4800 MHz
Figure 2
120 MHz / DIV
6000 MHz
Noise Figure Plot, from Rohde and Schwarz FSEK3 + FSEM30
Application Note AN219, Rev. 1.0
9 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
Table 3
Frequency / MHz
4800
4850
4900
4950
5000
5050
5100
5150
5200
5250
5300
5350
5400
5450
5500
5550
5600
5650
5700
5750
5800
5850
5900
5950
6000
1
1
Noise Figure, Tabular Data
NF / dB
Noise Temperature / K
1.29
1.27
1.31
1.29
1.29
1.27
1.27
1.28
1.26
1.28
1.26
1.24
1.26
1.27
1.29
1.3
1.29
1.31
1.33
1.35
1.31
1.37
1.39
1.38
1.4
100.7
98.8
102.5
100.3
100
98.1
98.5
99.8
97.3
99.6
97.3
95.9
97.7
98.4
100.4
101.6
100.1
102.2
103.7
105.8
102.5
107.7
109
108.8
110.5
Taken with Rohde & Schwarz FSEM30 + FSEK3; System Preamplifier: MITEQ 4-8 GHz LNA
Application Note AN219, Rev. 1.0
10 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.2
1 dB Compression Point
Gain Compression at 5470 MHz, VCC = +3.0 V, I = 14.2mA, VCE = 2.1V, T = 25°C:
Rohde & Schwarz ZVB20 Vector Network Analyzer is set up to sweep input power to LNA at a fixed frequency
of 5470 MHz. X-axis of VNA screen-shot below shows input power to LNA being swept from –30 to –5 dBm.
ZVB20 output power over sweep range is calibrated at end of test cable (reference plane at input SMA
connector to Amplifier Under Test) with Rohde & Schwarz NRP-Z21 power sensor.
Input 1 dB compression point = -6.4 dBm
Output 1dB compression point = -6.4 + (Gain – 1dB) = -6.4 dBm + 14.5 dB = +8.1dBm
Trc1 S21 dB Mag 0.5 dB / Ref 15 dB
Cal int PCal Smo Offs
M 1 -21.72 dBm
• M 2 -6.40 dBm
S21
1
15.517 dB
14.517 dB
16.0
M1
15.5
15.0
M2
14.5
14.0
13.5
13.0
12.5
12.0
Ch1
Start -30 dBm
Freq 5.47 GHz
Stop -5 dBm
7/2/2010, 10:57 AM
Figure 3
Input 1 dB Compression Point
Application Note AN219, Rev. 1.0
11 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.3
Gain
Input / Output Matching Circuits of LNA reduce gain in 2.4 – 2.5 GHz band
Trc1 S21 dB Mag 5 dB / Ref 10 dB
Cal Smo Offs
S21
20
M 2M 3
M1
1
M1
•M 2
M3
M4
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
15.550
15.522
14.728
6.3024
dB
dB
dB
dB
15
10
M4
5
0
-5
-10
-15
-20
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
7/2/2010, 10:47 AM
Figure 4
Forward Gain
Application Note AN219, Rev. 1.0
12 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.4
Input Return Loss
Trc1 S11 dB Mag 3 dB / Ref 0 dB
Cal Smo Offs
1
M1
•M 2
M3
M4
S11
6
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
-11.417
-17.776
-10.628
-2.5694
dB
dB
dB
dB
3
0
M4
-3
-6
-9
M1
M3
-12
-15
M2
-18
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
7/2/2010, 10:46 AM
Figure 5
Input Return Loss in dB
Application Note AN219, Rev. 1.0
13 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
Trc1 S11 Smith
Ref 1 U
Cal Smo Offs
1
1
S11
M 1 5.150000 GHz
0.5
M1
0
0.2
0.5
1M 2
64.470
j28.328
875.45
2
• M 2 5.470000 GHz 60.596
-j8.8572
3.285
M 3 5.825000 GHz 29.968
-j13.165
5
2.075
M 4 2.500000 GHz 7.7591
-j11.635
5.472
2
5
Ω
Ω
pH
Ω
Ω
pF
Ω
Ω
pF
Ω
Ω
pF
M3
M4
-5
-0.5
-2
-1
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
7/2/2010, 10:46 AM
Figure 6
Input Return Loss, Smith Chart
Application Note AN219, Rev. 1.0
14 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.5
Output Return Loss
Trc1 S22 dB Mag 5 dB / Ref 0 dB
Cal Smo Offs
1
M1
•M 2
M3
M4
S22
10
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
-12.596
-23.936
-12.864
-1.4291
dB
dB
dB
dB
5
M4
0
-5
-10
M1 M3
-15
-20
M2
-25
-30
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
7/2/2010, 10:49 AM
Figure 7
Output Return Loss in dB
Application Note AN219, Rev. 1.0
15 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
Trc1 S22 Smith
Ref 1 U
Cal Smo Offs
1
1
S22
M 1 5.150000 GHz
M4
0.5
M2
0
0.2
0.5
1
M3
40.928
-j20.006
1.545
2
• M 2 5.470000 GHz 44.828
j1.8874
54.917
M 3 5.825000 GHz 79.781
j865.16
5
23.639
M 4 2.500000 GHz 5.3841
j28.032
1.785
2
5
Ω
Ω
pF
Ω
Ω
pH
Ω
mΩ
pH
Ω
Ω
nH
M1
-5
-0.5
-2
-1
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
7/2/2010, 10:49 AM
Figure 8
Output Return Loss, Smith Chart
Application Note AN219, Rev. 1.0
16 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.6
Reverse Isolation
Trc1 S12 dB Mag 10 dB / Ref 0 dB
Cal Smo Offs
1
M1
•M 2
M3
M4
S12
0
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
-21.266
-20.342
-20.082
-41.220
dB
dB
dB
dB
-10
M 2M 3
M1
-20
-30
M4
-40
-50
-60
-70
-80
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
7/2/2010, 10:48 AM
Figure 9
Reverse Isolation
Application Note AN219, Rev. 1.0
17 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
Trc1 S12 dB Mag 10 dB / Ref 0 dB
Cal Smo Offs
1
M1
M2
M3
•M 4
S12
0
-10
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
-14.933
-14.826
-15.209
-32.132
dB
dB
dB
dB
M 1M 2M 3
-20
M4
-30
-40
-50
-60
-70
-80
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
7/8/2010, 9:27 AM
Figure 10
Reverse Isolation, Amplifier DC Power turned off
Application Note AN219, Rev. 1.0
18 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.7
Amplifier Stability
Rohde and Schwarz ZVB Network Analyzer calculates and plots stability factor “µ1” of the BFP740FESD
1
amplifier in real time. Stability Factor µ1 is defined as follows :
Figure 11
Definition of Stability Factor µ1
The necessary and sufficient condition for Unconditional Stability is µ1 > 1.0. In the plot, µ1 > 1.0 over 10 MHz
– 12 GHz; amplifier is Unconditionally Stable over 10 MHz – 12 GHz frequency range.
Trc1 µ1 Lin Mag 200 mU/ Ref 1.4 U
Cal Smo Offs
1
M1
M2
M3
•M 4
µ1
2600.0
5.150000
5.470000
5.825000
2.500000
GHz
GHz
GHz
GHz
1.7795
1.6652
1.4741
1.1905
U
U
U
U
2400.0
2200.0
2000.0
M1
1800.0
M2
1600.0
M3
1400.0
M4
1200.0
1000.0
Ch1
Start 10 MHz
Pwr -25 dBm
Stop 12 GHz
7/8/2010, 9:37 AM
Figure 12
1
Stability Factor
“Fundamentals of Vector Network Analysis”, Michael Hiebel, 4th edition 2008, pages 175 – 177, ISBN 978-3-939837-06-0
Application Note AN219, Rev. 1.0
19 / 29
2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.8
Third Order Intercept Point
In-Band Third Order Intercept (IIP3) Test.
Input Stimulus: f1=5470 MHz, f2=5471 MHz, -20 dBm each tone.
Input IP3 = -20 + (54.3 / 2) = +7.2 dBm.
Figure 13
Output IP3 = +7.2 dBm + 15.5 dB gain = +22.7 dBm.
Carrier and Intermodulation Products at LNA’s Output
Application Note AN219, Rev. 1.0
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2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.9
Turn-On / Turn-Off Time
The amplifier is tested for turn-on / turn-off time. See diagram below. The RF signal generator runs
continuously at a power level sufficient to drive the output of the LNA to approximately 0 dBm when the LNA has
DC power ON.
Agilent
DSO6104A
Digital
Oscilloscope
+3 Volts
Ch. 1 (Trigger, edge)
1 Megaohm input Z
Amplifier
6 dB
Attenuator
Pad
Signal
Generator
f=5470 MHz
Agilent
8473B
Detector
Ch. 2 (50 ohm input Z)
! Note !
Set Ch. 2 Input Impedance to 50 ohms, not 1M ohm! 1M ohm
setting will not allow detector to discharge rapidly, and will give
erroneous results to turn-off time measurment, e.g. will indicate
excessively long turn-off times.
1. Signal Generator set such that output power of BFP740F LNA is approx. 0
dBm when LNA is powered ON
2. Channel 1 of oscilloscope monitors input power supply voltage to
Amplifier (+3.0 volts when ON, ~ 0 volts when OFF)
3. Channel 2 of oscilloscope monitors rectified RF output of Amplifier
4. To make measurement of turn-on time, turn power supply OFF, reset
o’scope, setup trigger to trigger on rising edge of Ch.1
5. To make measurement of turn-off time, turn power supply ON, reset
o’scope, setup trigger to trigger on falling edge of Ch. 1
Figure 14
Test setup for Turn-On / Turn-Off measurements
Application Note AN219, Rev. 1.0
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2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.9.1
Turn On Time
Refer to oscilloscope screen-shot below. Upper trace (yellow, Channel 1) is the DC power supply turn-on step
waveform whereas the lower trace (green, Channel 2) is the rectified RF output signal of the LNA stage.
Amplifier turn-on time is aproximately 50 ns, or 0.05 ms. Main source of time delay in the LNA turn-on and
turn-off events are the R-C time constants formed by (R3 * C4), [(R2+R3) * C3], etc. Charge storage has been
minimized in this circuit so as to speed up turn on and turn off times. (Refer to Figure 1).
Figure 15
Turn On Time
Application Note AN219, Rev. 1.0
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2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Measured Graphs
5.9.2
Turn Off Time
Rectified RF output signal (lower green trace) takes approximately ~ 125ns, or ~0.1ms to settle out after power
supply is turned off. Note that input impedance of digital oscilloscope which senses RF Detector Diode output is
set to 50Ω, rather than 1 MΩ, to permit RF Detector Diode to rapidly discharge after Amplifier is turned off.
If input impedance of oscilloscope is set to 1 MΩ, the RF Detector will have to discharge through this 1 MΩ
impedance, giving excessively long results for the turn-off time measurement.
Figure 16
Turn Off time
Application Note AN219, Rev. 1.0
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2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Details of PC Board Construction
6
Details of PC Board Construction
Figure 17
View of entire PC Board, Top / Component Side
Figure 18
Close-In View of LNA Section
Application Note AN219, Rev. 1.0
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2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Details of PC Board Construction
Figure 19
Backside of PCB
PC board is fabricated from standard, low-cost “FR4” glass-epoxy material. A cross-section diagram of the PC
board is given below.
PCB CROSS SECTION
0.012 inch / 0.305 mm
TOP LAYER
INTERNAL GROUND PLANE
0.028 inch / 0.711 mm ?
LAYER FOR MECHANICAL RIGIDITY OF PCB, THICKNESS HERE NOT CRITICAL AS
LONG AS TOTAL PCB THICKNESS DOES NOT EXCEED 0.045 INCH / 1.14 mm
(SPECIFICATION FOR TOTAL PCB THICKNESS: 0.040 + 0.005 / - 0.005 INCH;
1.016 + 0.127 mm / - 0.127 mm )
BOTTOM LAYER
Figure 20
PCB Layer Information
Application Note AN219, Rev. 1.0
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2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
SOT343 Package Outline and Foot Print
7
SOT343 Package Outline and Foot Print
Dinensions in millimeters. Note maximum package height is 0.59 mm / 0.023 inch
Figure 21
SOT344 package outline and recommended foot print
Application Note AN219, Rev. 1.0
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2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
ESD Protection
8
ESD Protection
Electrostatic discharge (ESD) plays an important role when ESD sensitive devices are connected to exposed
interfaces or antennas that can be touched by humans. This is usually applicable to low noise amplifiers (LNAs)
and therefore LNAs must be properly protected against ESD in order to avoid irreversible damage of the LNA.
For mobile applications low voltage supply and low current consumption is a major issue that requires new
technologies with smaller transistor structures. However, the smaller the transistor structure the more sensitive
the transistor is to ESD events. Therefore, RF-LNAs based on new front-end technologies have already ESD
protection elements integrated on-chip, e.g. BFP740ESD, BFP640FESD, BFP540FESD. These on-chip ESD
protection techniques are always a compromise between good ESD protection and RF performance. Integrated
RF ESD concepts hardly ever achieve an ESD protection above ±2 kV according HBM. An on-chip ESD
protection of ±1 kV HBM (component level ESD test JEDEC JESD 22-A115) is quite sufficient to protect the
chip from ESD events in the manufacturing environment where stringent measures are taken to prevent
electrostatic buildup. However in the field, exposed antennas, for example, always require higher ESD
protection levels of at least ±8kV up to ±15kV. Additional the more stringent system level test according to
IEC61000-4-2 is applied. Therefore a special ESD protection becomes mandatory to handle the majority of the
ESD current. An ESD protection based on silicon TVS diodes fits perfect to keep the residual ESD stress for the
subsequent device as small as possible.
For high frequency applications (2.4GHz and 5GHz WLAN) ESD protection diodes with ultra low line
capacitances are required. Infineon offers ultra low clamping voltage and ultra low capacitance, 0.2pF line
capacitance, ESD protection diodes in leadless packages of EIA case 0402 (TSLP-2-17) as well as 0201
(TSSLP-2-1):
ESD0P2RF-02LRH / -02LS
The Infineon TVS diode ESD0P2RF has a line capacitance of only 0.2 pF and comes in either a TSLP-2-17
package (1 mm x 0.6 mm x 0.39 mm) or a super small TSSLP-2-1 package (0.62 mm x 0.32 mm x 0.31 mm).
The ESD0P2 ESD diode is a bidirectional TVS diode with a maximum working voltage of ±5.3V. It is capable of
handling TX power levels of up to +20dBm without influencing the signal integrity, EVM and harmonic
generation. Therefore it is well suited for WLAN 2.4GHz and for a lot of 5GHz applications as well.
Application Note AN219, Rev. 1.0
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2010-07-12
BFP740ESD
BFP740ESD for 5-6GHz WLAN applications
Authors
Authors
Jerry Wevers, Senior Staff Engineer of Business Unit “RF and Protection Devices”
Dietmar Stolz, Staff Engineer of Business Unit “RF and Protection Devices”
Application Note AN219, Rev. 1.0
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2010-07-12
w w w . i n f i n e o n . c o m
Published by Infineon Technologies AG
AN219
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