AN10885 Doherty RF performance analysis using the

AN10885
Doherty RF performance analysis using the BLF7G22LS-130
Rev. 02 — 25 February 2010
Application note
Document information
Info
Content
Keywords
RF power transistors, Doherty architecture, LDMOS, power amplifier, RF
performance, Digital PreDistortion (DPD), UMTS, W-CDMA,
BLF7G22LS-130
Abstract
This application note describes a state-of-the-art power amplifier design
for UMTS base stations using the BLF7G22LS-130 LDMOS transistor
AN10885
NXP Semiconductors
Doherty RF performance analysis using the BLF7G22LS-130
Revision history
Rev
Date
Description
02
20100225
Modifications
01
20100106
•
•
New template applied and Legal texts updated.
•
Figure 15 “BLF7G22LS-130 Doherty test circuit PCB layout” on page 11: Component
Q1 rotated 180 degrees.
Figure 8 “Power gain and efficiency as a function of output power” on page 7: Title and
Figure notes updated.
Initial version
Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
AN10885_2
Application note
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Rev. 02 — 25 February 2010
© NXP B.V. 2010. All rights reserved.
2 of 15
AN10885
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Doherty RF performance analysis using the BLF7G22LS-130
1. Introduction
This application note describes a state-of-the-art power amplifier design for UMTS base
stations using the BLF7G22LS-130 LDMOS power transistor. The amplifier design
characteristics and the test methods used to determine the RF performance are also
described.
The amplifier uses two BLF7G22LS-130 devices in a Doherty architecture on a Rogers
3006 PCB having a thickness of 0.64 mm (0.025”). The design ensures high-efficiency
while maintaining a very similar peak power capability of two transistors combined. The
input and output sections are internally matched, benefiting the amplifier design with high
gain and good gain flatness and phase linearity over a wide frequency band.
The BLF7G22LS-130 is a seventh generation LDMOS device using NXP
Semiconductor’s advanced LDMOS process.
2. Test summary
The amplifier was characterized under the following conditions:
• Network analyzer measurements for power gain (Gp), delay (td) and Input Return
Loss (IRL) at:
– output power (PL) = 47 dBm
– drain-source voltage (VDS) = 28 V
– main power amplifier quiescent drain current (IDq) = 900 mA
– gate-source voltage of peak amplifier (VGS (peak)) = 0.5 V
• CDMA Interim Standard (IS-95) at VDS = 28 V, IDq = 900 mA and VGS = 0.5 V
• 2-carrier W-CDMA (15 MHz spacing), VDS = 28 V, IDq = 900 mA and VGS (peak) = 0.5 V
• Peak output power (P3dB) capability using CDMA IS95 signal, ratio of peak power to
average power = 9.7 dB at 0.01 % probability, VDS = 28 V, IDq = 900 mA and
VGS (peak) = 0.5 V
• Output power 3 dB compression point using pulsed signal, width = 12 μs, 10 % duty
cycle at VDS = 28 V, IDq = 900 mA and VGS (peak) = 0.5 V
• Digital PreDistortion (DPD) measurements using a DPD system, 2-carrier W-CDMA
signal, Peak-to-average ratio (PAR) = 7.5 dB at 0.01 % probability (total signal),
VDS = 28 V, IDq = 900 mA, VGS (peak) = 0.5 V
Table 1.
AN10885_2
Application note
Performance summary
Frequency
(GHz)
Gp at
47 dBm
(dB)
IRL at
P3dB
47 dBm pulsed
(dB)
12 μs pulse
width
(dBm)
IMD3 (no
correction) at
47 dBm
(dB)
IMD3 with
DPD at
47 dBm
(dB)
Drain efficiency
(ηD) at 47 dBm
(%)
2.11
17.2
−14.0
54.4
−31.3/−30.9
−60.2/−59.6
44.2
2.14
17.3
−15.5
54.4
−33.4/−33.0
−59.8/−58.4
42.9
2.17
17.2
−17.0
54.4
−33.8/−34.7
−59.4/−57.9
42.2
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Rev. 02 — 25 February 2010
© NXP B.V. 2010. All rights reserved.
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AN10885
NXP Semiconductors
Doherty RF performance analysis using the BLF7G22LS-130
3. RF performance
3.1 Network analyzer measurements
Network analyzer measurements were performed under the following conditions:
•
•
•
•
PL = 47 dBm
VDS = 28 V
IDq = 900 mA
VGS (peak) = 0.5 V
001aal197
19
td
(ns)
17
−4
3.0
15
−8
2.6
13
−12
2.2
11
−16
1.8
9
2.050
2.095
2.140
−20
2.185
2.230
f (GHz)
Power gain and input return loss as a function
of frequency
AN10885_2
Application note
001aal199
3.4
IRL
(dB)
Gp
(dB)
Fig 1.
0
1.4
2.050
Fig 2.
2.095
2.140
2.185
2.230
f (GHz)
Delay as a function of frequency
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Rev. 02 — 25 February 2010
© NXP B.V. 2010. All rights reserved.
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AN10885
NXP Semiconductors
Doherty RF performance analysis using the BLF7G22LS-130
3.2 IS-95 measurements
The IS-95 measurements were performed under the following conditions:
• Bias: VDS = 28 V
• IDq = 900 mA
• VGS (peak) = 0.5 V
001aal200
20
100
ηD
(%)
Gp
(dB)
(1)
(2)
(3)
18
80
001aal227
−25
ACPR
(dBc)
(1)
(2)
(3)
(4)
(5)
(6)
−45
60
16
(4)
(5)
(6)
40
14
−65
(7)
(8)
(9)
(10)
(11)
(12)
20
12
10
0
35
39
43
47
51
PL(AV) (dBm)
−85
35
39
43
47
51
PL (dBm)
(1) Gp = 2110 MHz.
(1) 2110 MHz − 885 kHz.
(2) Gp = 2140 MHz.
(2) 2110 MHz + 885 kHz.
(3) Gp = 2170 MHz.
(3) 2140 MHz − 885 kHz.
(4) ηD = 2110 MHz.
(4) 2140 MHz + 885 kHz.
(5) ηD = 2140 MHz.
(5) 2170 MHz − 885 kHz.
(6) ηD = 2170 MHz.
(6) 2170 MHz + 885 kHz.
(7) 2110 MHz − 1.98 MHz.
(8) 2110 MHz + 1.98 MHz.
(9) 2140 MHz − 1.98 MHz.
(10) 2140 MHz + 1.98 MHz.
(11) 2170 MHz − 1.98 MHz.
(12) 2170 MHz + 1.98 MHz.
Fig 3.
Power gain and efficiency as a function of
average output power, IS-95
AN10885_2
Application note
Fig 4.
Adjacent Channel Power Ratio (ACPR) as a
function of output power
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Rev. 02 — 25 February 2010
© NXP B.V. 2010. All rights reserved.
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AN10885
NXP Semiconductors
Doherty RF performance analysis using the BLF7G22LS-130
3.3 2-carrier W-CDMA measurements
These measurements were performed under the following conditions:
•
•
•
•
•
Channel bandwidth = 3.84 MHz, spacing: 15 MHz
Bias: VDS = 28 V
IDq = 900 mA
VGS (peak) = 0.5 V
Heatsink temperature (Th) = 25 °C
001aal228
20
ηD
(%)
Gp
(dB)
18
(1)
(2)
(3)
80
001aal229
0
100
IMD3
(dBc)
−20
60
16
(4)
(5)
(6)
(1)
(2)
(3)
(4)
(5)
(6)
40
14
−40
20
12
10
0
35
39
43
47
51
PL(AV) (dBm)
−60
35
37
39
41
(1) Gp = 2110 MHz.
(1) 2110 MHz IMD3 low.
(2) Gp = 2140 MHz.
(2) 2110 MHz IMD3 high.
(3) Gp = 2170 MHz.
(3) 2140 MHz IMD3 low.
(4) ηD = 2110 MHz.
(4) 2140 MHz IMD3 high.
(5) ηD = 2140 MHz.
(5) 2170 MHz IMD3 low.
(6) ηD = 2170 MHz.
(6) 2170 MHz IMD3 high.
Fig 5.
Power gain and efficiency as a function of
average output power, 2-carrier W-CDMA
AN10885_2
Application note
Fig 6.
43
45
47
49
PL (dBm)
IMD3 as a function of output power, 2-carrier
W-CDMA
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© NXP B.V. 2010. All rights reserved.
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Doherty RF performance analysis using the BLF7G22LS-130
3.4 Peak output power measurements
Two methods were used to measure peak output power.
• Using a standard IS-95 signal (PAR = 9.7 dB at 0.01 % probability on the CCDF),
determining the output power where the PAR reaches 6.7 dB at 0.01 % probability on
the CCDF, measured as the 3 dB compression point
• Using the pulsed signal, measuring the 3 dB compression points
The peak power measurements were performed under the following conditions:
• Bias: VDS = 28 V
• IDq = 900 mA
• VGS (peak) = 0.5 V
001aal230
55.1
PL(M)
(dBm)
001aal231
18
55
Gp
(dB)
54.9
17
54.7
16
54.5
50
(4)
(5)
(6)
ηD
(%)
45
40
(1)
(2)
(3)
35
30
15
25
54.3
20
14
15
54.1
2100
10
55
13
2120
2140
2160
2180
35
40
f (MHz)
45
50
PL (dBm)
(1) f = 2110 MHz.
(2) f = 2140 MHz.
(3) f = 2170 MHz.
(4) f = 2110 MHz.
(5) f = 2140 MHz.
(6) f = 2170 MHz.
Fig 7.
Peak output power as a function of frequency
AN10885_2
Application note
Fig 8.
Power gain and efficiency as a function of
output power
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© NXP B.V. 2010. All rights reserved.
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AN10885
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Doherty RF performance analysis using the BLF7G22LS-130
3.5 DPD measurements
The DPD measurements were performed using an in-house designed DPD system.
The following DPD measurements were performed under the following conditions:
•
•
•
•
fc = 2110 MHz
DPD system: 2-carrier W-CDMA signal, spacing: 15 MHz
VDS = 28 V, IDq = 900 mA, VGS (peak) = 0.5 V
IMD3 at 47.23 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) uncorrected
(no DPD applied): −31.3 dB and −30.9 dB
• IMD3 at 47.24 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) corrected
(DPD applied): −60.2 dB and −59.6 dB
• IMD3 correction = 28.9 dB and 28.7 dB
PL 40
(dBm) 30
20
10
0
−10
−20
−30
−40
−50
2085
2090
2095
2100
2105
2110
2115
2120
2125
2130
2135
f (MHz)
001aal232
IMD3 at 47.23 dBm, 0 dB attenuation.
Fig 9.
DPD uncorrected, fc = 2110 MHz
40
PL
30
(dBm)
20
10
0
−10
−20
−30
−40
−50
−60
2085
2090
2095
2100
2105
2110
2115
2120
2125
2130
2135
f (MHz)
001aal233
IMD3 at 47.24 dBm, 5 dB attenuation.
Fig 10. DPD corrected, fc = 2110 MHz
AN10885_2
Application note
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Rev. 02 — 25 February 2010
© NXP B.V. 2010. All rights reserved.
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AN10885
NXP Semiconductors
Doherty RF performance analysis using the BLF7G22LS-130
The following DPD measurements were performed under the following conditions:
•
•
•
•
fc = 2140 MHz
DPD system: 2-carrier W-CDMA signal, spacing: 15 MHz
VDS = 28 V, IDq = 900 mA, VGS (peak) = 0.5 V
IMD3 at 47.16 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) uncorrected:
−33.4 dB and −33.0 dB
• IMD3 at 47.14 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) corrected:
−59.8 dB and −58.4 dB
• IMD3 correction = 26.4 dB and 25.4 dB
40
PL
30
(dBm)
20
10
0
−10
−20
−30
−40
−50
−60
2115
2120
2125
2130
2135
2140
2145
2150
2155
2160
2165
f (MHz)
001aal234
IMD3 at 47.16 dBm, 5 dB attenuation.
Fig 11. DPD uncorrected, fc = 2140 MHz
40
PL
30
(dBm)
20
10
0
−10
−20
−30
−40
−50
−60
2115
2120
2125
2130
2135
2140
2145
2150
2155
2160
2165
f (MHz)
001aal235
IMD3 at 47.14 dBm, 5 dB attenuation.
Fig 12. DPD corrected, fc = 2140 MHz
AN10885_2
Application note
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Rev. 02 — 25 February 2010
© NXP B.V. 2010. All rights reserved.
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NXP Semiconductors
Doherty RF performance analysis using the BLF7G22LS-130
The following DPD measurements were performed under the following conditions:
•
•
•
•
fc = 2170 MHz
DPD system: 2-carrier W-CDMA signal, spacing:15 MHz
VDS = 28 V, IDq = 900 mA, VGS (peak) = 0.5 V
IMD3 at 47.04 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) uncorrected:
−33.8 dB and −34.7 dB
• IMD3 at 47.13 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) corrected:
−59.4 dB and −57.9 dB
• IMD3 correction = 25.6 dB and 23.2 dB
40
PL
30
(dBm)
20
10
0
−10
−20
−30
−40
−50
−60
2145
2150
2155
2160
2165
2170
2175
2180
2185
2190
2195
f (MHz)
001aal236
IMD3 at 47.04 dBm, 5 dB attenuation.
Fig 13. DPD uncorrected, fc = 2170 MHz
40
PL
30
(dBm)
20
10
0
−10
−20
−30
−40
−50
−60
2145
2150
2155
2160
2165
2170
2175
2180
2185
2190
2195
f (MHz)
001aal237
IMD3 at 47.13 dBm, 5 dB attenuation.
Fig 14. DPD corrected, fc = 2170 MHz
AN10885_2
Application note
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Rev. 02 — 25 February 2010
© NXP B.V. 2010. All rights reserved.
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Doherty RF performance analysis using the BLF7G22LS-130
4. BLF7G22LS-130 Doherty test circuit
R5
R3
R12
R2
C2
R7
Q1
C1
L1
R1
R13
C5
R14 L2
R11
R10
Q2
C4
C7
R6
D1 R8
C20
C10
C9
C15
C13
C17
R9
R4
C3
C8
C6
Q3
X1
C18
C17
C11
C12
C14
C16
R15
C6
Q3
C19
C3
R16
D1 R8
R9
R17
C7
Q2
R11
R5
R2
R12
R3
R7
C2
C1
Q1
R1
L1
C5
R13
C18
C13
C15
C9
C10
R10
C4
add metal
R14 L2
C20
001aal238
Fig 15. BLF7G22LS-130 Doherty test circuit PCB layout
AN10885_2
Application note
All information provided in this document is subject to legal disclaimers.
Rev. 02 — 25 February 2010
© NXP B.V. 2010. All rights reserved.
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Doherty RF performance analysis using the BLF7G22LS-130
4.1 BLF7G22LS-130 Doherty test circuit components
Table 2.
BLF7G22LS-130 Doherty test circuit components
Designator
Description
Part identifier
Manufacturer
Input PCB
BLF7G22LS-130 Doherty PA Input-Rev1
Ohio circuits
Output PCB
Rogers 3006; εr = 6.15, ± 0.15;
thickness 0.64 mm (0.025”);
35 μm (1 oz.) copper on each
side; Ref. 1 on page 13
BLF7G22LS-130 Doherty PA Output-Rev1 Ohio circuits
Q1
78L08 voltage regulator
NJM#78L08UA-ND
NJR
Q2
2N2222 NPN transistor
MMBT2222
Fairchild
Q3
BLF7G22LS-130
BLF7G22LS-130
NXP Semiconductors
R1, R14
9.1 Ω
CRCW08059R09FKEA
Vishay Dale
R2, R3, R17 430 Ω
CRCW0805432RFKEA
Vishay Dale
R4
75 Ω
CRCW080575R0FKTA
Vishay Dale
R5
200 Ω, potentiometer
3214-1-201E
Bourns
R6
2 kΩ
CRCW08052K00FKTA
Vishay Dale
R7, R12
1.1 kΩ
CRCW08051K10FKEA
Vishay Dale
R8
11 kΩ
CRCW080511K0FKEA
Vishay Dale
R9
5.1 Ω
CRCW08055R11FKEA
Vishay Dale
R10
5.1 kΩ
CRCW08055K10FKTA
Vishay Dale
R11
910 Ω
CRCW0805909RFKTA
Vishay Dale
R13
499 Ω, 0.5 W
CRCW2010499RFKEF
Vishay Dale
R15
SMT 2010 50 Ω RL
-
EMC
R16
0Ω
-
Vishay Dale
X1
3 dB, hybrid coupler, 30 W
1J503S
Anaren
L1, L2
Ferroxcube bead
2743019447
Fair Rite
C1, C2,
C4
100 nF ceramic 0805
S0805W104K1HRN-P4
MultiComp
C3
4.7 μF
C4532X7R1H475M
TDK
C5
1 μF
C3216X7R1H105K
TDK
C6, C7, C19 15 pF
600F
American Technical Ceramics
C8
12 pF
600F
American Technical Ceramics
C13, C14
15 pF
ATC100B150JT500X
American Technical Ceramics
C9, C10,
C11, C12
1 μF
GRM31CR72A105KA01L
MuRata
C15, C16
10 μF
GRM32DF51H106ZA01L
MuRata
C20
220 μF, 50 V electrolytic SMT
PCE3474CT-ND
Panasonic
C17
1.5 pF
600F
American Technical Ceramics
C18
1.8 pF
600F
American Technical Ceramics
AN10885_2
Application note
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Doherty RF performance analysis using the BLF7G22LS-130
5. Abbreviations
Table 3.
Abbreviations
Acronym
Description
ACPR
Adjacent Channel Power Ratio
CCDF
Complementary Cumulative Distribution Function
DPD
Digital PreDistortion
LDMOS
Laterally Diffused Metal-Oxide Semiconductor
PAR
Peak-to-Average power Ratio
SMT
Surface-Mount Technology
UMTS
Universal Mobile Telecommunications System
W-CDMA
Wideband Code Division Multiple Access
6. References
[1]
AN10885_2
Application note
Data sheet 1.3000; RO3000 Series High Frequency Circuit Materials −
Advanced Circuit Materials Division; Rogers Corporation.
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© NXP B.V. 2010. All rights reserved.
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7. Legal information
7.1
Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
7.2
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Disclaimers
Limited warranty and liability — Information in this document is believed to
be accurate and reliable. However, NXP Semiconductors does not give any
representations or warranties, expressed or implied, as to the accuracy or
completeness of such information and shall have no liability for the
consequences of use of such information.
In no event shall NXP Semiconductors be liable for any indirect, incidental,
punitive, special or consequential damages (including - without limitation - lost
profits, lost savings, business interruption, costs related to the removal or
replacement of any products or rework charges) whether or not such
damages are based on tort (including negligence), warranty, breach of
contract or any other legal theory.
Notwithstanding any damages that customer might incur for any reason
whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards
customer for the products described herein shall be limited in accordance
with the Terms and conditions of commercial sale of NXP Semiconductors.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
AN10885_2
Application note
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in medical, military, aircraft,
space or life support equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors accepts no liability for inclusion and/or use of
NXP Semiconductors products in such equipment or applications and
therefore such inclusion and/or use is at the customer’s own risk.
NXP Semiconductors does not accept any liability related to any default,
damage, costs or problem which is based on a weakness or default in the
customer application/use or the application/use of customer’s third party
customer(s) (hereinafter both referred to as “Application”). It is customer’s
sole responsibility to check whether the NXP Semiconductors product is
suitable and fit for the Application planned. Customer has to do all necessary
testing for the Application in order to avoid a default of the Application and the
product. NXP Semiconductors does not accept any liability in this respect.
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a prior
authorization from national authorities.
7.3
Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
All information provided in this document is subject to legal disclaimers.
Rev. 02 — 25 February 2010
© NXP B.V. 2010. All rights reserved.
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8. Contents
1
2
3
3.1
3.2
3.3
3.4
3.5
4
4.1
5
6
7
7.1
7.2
7.3
8
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Test summary. . . . . . . . . . . . . . . . . . . . . . . . . . . 3
RF performance . . . . . . . . . . . . . . . . . . . . . . . . . 4
Network analyzer measurements . . . . . . . . . . . 4
IS-95 measurements . . . . . . . . . . . . . . . . . . . . 5
2-carrier W-CDMA measurements . . . . . . . . . . 6
Peak output power measurements . . . . . . . . . . 7
DPD measurements . . . . . . . . . . . . . . . . . . . . . 8
BLF7G22LS-130 Doherty test circuit . . . . . . . 11
BLF7G22LS-130 Doherty test circuit
components . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . 13
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Legal information. . . . . . . . . . . . . . . . . . . . . . . 14
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
© NXP B.V. 2010.
All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
Date of release: 25 February 2010
Document identifier: AN10885_2