推荐星级：
- 1
- 2
- 3
- 4
- 5
AS3911 general purpose demo Hardware description
资料介绍
AS3911相关的技术文档，开发RFID的相关资料
部分文件列表
| 文件名 | 大小 |
| 1568425613ams_AS3911_Operation_Manual-341285.pdf | 1M |
部分页面预览
（完整内容请下载后查看）austriamicrosystems AG
is now
ams AG
The technical content of this austriamicrosystems application note is still valid.
Contact information:
Headquarters:
ams AG
Tobelbaderstrasse 30
8141 Unterpremstaetten, Austria
Tel: +43 (0) 3136 500 0
e-Mail:
Please visit our website at www.ams.com
AS3911
AS3911 general purpose demo
Hardware description
Application noe
Rev 1V00 December 2011
Application engineer: Thomas Luecker
MarketinManager: Mark Dickson
Proprietary and Confidential
1
1
2
3
3.1
3.2
3.3
Disclaimer............................................................................................................ 2
Introduction.......................................................................................................... 3
Hardware............................................................................................................. 4
Block diagram.........................................................................................................4
EMC and Power supply concept..............................................................................5
Digital section ( micro controller) ...........................................................................6
3.3.1 Programming header P1 ....................................................................................6
Analog section ........................................................................................................7
3.4.1 Power concept...................................................................................................8
3.4.2 Antenna stage....................................................................................................
3.4.3 Capacitive wakeup ............................................................................................9
Measurement ..................................................................................................... 9
Current consumption..............................................................................................9
Antenna stage........................................................................................................9
Measurement of the antenna Parameters.............................................................9
Determination of the Antenna resistor................................................................10
Matching of the driver......................................................................................11
Verification of the Q factor in the timomain ..................................................12
Measurement with Standard assembly f 2200 Ohm. ............................................13
Layout recommendations ....................................................................................13
PCB stack ......................................................................................................14
Gerber Top...................................................................................................14
Gerber Bottom ...................................................................................................15
Assembly Top....................................................................................................16
Bill of Material ................................................................................................17
Version History.........................................................................................18
3.4
4
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13
5
1 Disclaimer
Please note that the provded reference design board, evaluation board, verification board or
demonstration board (hereafter named “demonstration circuit board”) are experimental
printed circuit boards and are therefore intended for device demonstration and evaluation
purposes only for semiconductor integrated circuits supplied by austriamicrosystems. The
demonstration circuit boards are not production qualified. This application has not been
certified accrding to CE/FCC/EMC requirements. Device parameters measured with these
demonsration circuit boards may not represent typical production test data.
THDEMONSTRATION CIRCUIT BOARDS ARE SUPPLIED WITHOUT WARRANTY
OF ANY KIND, EXPRESSED, IMPLIED OR STATUTORY, INCLUDING BUT NOT
LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE. AUSTRIAMICROSYSTEMS ACCEPTS NO
LIABILITY WHATSOEVER ARISING AS A RESULT OF THE USE OF THESE
DEMONSTRATION CIRCUIT BOARDS.
Proprietary and Confidential
2
The fee associated with the demonstration circuit boards is a nonrecurring engineering
fee (NRE) to partially defray the hardware and software engineering costs associated with the
development and provision of the demonstration circuit boards.
The demonstration circuit boards may be operated for demonstration or evaluation purposes
in non-residential areas only. austriamicrosystems’ understanding is that the customer’s
products using the semiconductor integrated circuits shall be designed in compliance with all
applicable requirements of the appropriate regulatory agency (e.g. FCC, ETSI, CE, JQA,
etc.) and will, upon testing and release, be in compliance with these regulatory requirements.
Operation of the customer’s products must not cause harmful interference and must accept any
interference. This application shall not be offered for end-customer sale or lease until
certification is obtained.
2 Introduction
This application note describes the AS3911 general purpoe Demo board and is usage. The
general purpose board is made for a flexible use, hece the digital part can be separated from
the analogue part. This enables fast software dvelopment since the analogue part can be used
out of the box.
The analog section has several jumpers to allow custom antenna and capacitive electrodes to
be used.
Proprietary and Confidential
3
3 Hardware
3.1
Block diagram
The board compromise of a Micro controller with USB support, a LDO to supply the micro
controller and the HF reader IC AS3911.
3V3
5V
LDO
3V3
USB
Connector
Micro
Controller
USB
Differential
SPI
EMC Filter
5V
Matching
NW
Antenne Feedback
coil loop
Tuning Capacitor
bank
AS3911
Blocking Cap for
LDO’s of: VDD,
AGD, VSPA, VSPRFP
U2
Uchip
UA
EMC Filter Network
Matching network
Schematic level
Proprietary and Confidential
4
3.2
EMC and Power supply concept
For rejection of EMC due the rectangular carrier field generation, ferrite beads are placed
close to the supply with additional capacitors next to the connector.
C1
10u
L3
U1
BUS_PWR
VBUS
D-
VBUS
U2
+3.3V
1
3
2
VIN
VOUT
2
3
4
5
D-
C4
Ferritbeat
D-
D+
C5
1u
C6
1u
D3
Zener
D+
10u
D+
D1
24V
AS1360-33
D2
24V
D4
24V
C2
dnp
C3
BUS_GND
Shield
dnp
GND GND
GND GND
GND
GND GND GND
GND
GND
USB_MINI_B
L1
Ferritbeat
L2
Ferritbeat
GND
GND
Since the specification of USB-supply voltage can have wt case 4.5 Volt, the supply
Voltage of the device might vary. AS311 has an inteal rgulator that measure the voltage
and adjust the internal regulator such that the voltage on he output driver (for antenna) is
0.3Volt below the supply votage. This adjustmet assure that the digital noise on the supply
of the antenna driver can be rcted and the Voltagfor the antenna driver can be maximized.
Hence, for evaluation purpose, we have impd a jumper P5 which can be used to provide
an external voltage supply to the reader IC.
Proprietary and Confidential
5
3.3
Digital section ( micro controller)
VBUS
P1
R20
10k
+3.3V
C9
Header 8H
GND
R18
100n
10k
+3.3V +3.3V +3.3V
U3
PIC27FJ64GB002
C7
10n
R1
10k
R4
10k
R7
10k
R19
470
C10
10u
26
17
16
MCLR
PGED1
PGEC1
VCAP
1
2
DISVREG
R2
10k
R5
10k
R100
10k
8
GND
RP4/SOSCI
RA4
C11
3
4
9
RP2
RP3
RP6
RP5
RP9
RP7
RP8
GND
GND
GND
GND
7
18p
RA3
C12
PIC24FJ64GB
SCLK 28
MOSI 27
INTR 15
MISO 13
SEN 14
6
MCCLK
SCLK
MOSI
INTR
MISO
SEN
RA2
GND
18p
R13
R14
R15
R16
R17
220
220
220
220
220
220 R12
220 R8
8MHz
Y1
23
22
21
11
RP15
RP14
RP13
RB5
Plug
T1
R25 470
R26 470
R23 470
R24 470
220 R9
220 R10
220 R11
+3.3V
V_RF
+3.3V VBUS V_RF
D5
D6
D7
D8
C8
+3.3V
R21
27R
100n
R22
27R
R3
dnp 0R
R6
GND
D+
D-
P2
+3.3V
GN
Header 8H
•
•
The used micro controller is a PC24 FJGB002 with internal USB.
Three pins (Pin 1,2 and 3 of the micro controller) bing used for selection of
different Hardware versions of boards.
•
•
Four diodes (D5-D8) display the various condtions of the board.
The connector P2 can used as a alternatie connction to an external micro controller
or to connect to a new developed anasytem of AS3911. The selection can be
done by un mount the coupling resisto(R13-17).
3.3.1 Programming header P1
P1 is the programming header fhe microchip controller. The pin order on the header P1 is
exactly the same as being used on the microchip tool chain, hence no special adapter is
needed.
Proprietary and Confidential
6
3.4
Analog section
Following is the schematic of the analog section incl. AS3911 and its external components
Proprietary and Confidential
7
This setup is made to demonstrate almost all the capabilities of AS3911. The salient features
are:
•
•
•
•
•
•
•
Differential antenna
Capacitive wakeup (possibility to attach external electrodes)
Antenna tuning trimming capacitors
27MHz Crystal
supply noise rejection
High sensitivity
Low impedance driver stage
3.4.1 Power concept
AS3911 has internal LDO that needs to be decoupled with capacitors of 2.2 microF and 10
nF. These pins are
AGD (analogue ground)
VSP_D (to supply the logic of AS3911)
VSP_A (to supply the analogue part of AS3911)
VSP_RF (to supply the driver stage of AS3911)
AS3911 contains internal level shifter that enables to connect to micro controller with
different VDD than AS3911. Pin 1 shall be connected to the same Voltage as the supply of
the micro controller.
GND as well as the supply line are being connected with a ferrite bead to reject the EMC
disturbance caused by the HF driver.
3.4.2 Antenna stage
The Antenna stage consists of a two stage Filter network and a matching. The two stage filter
shall reject higher harmonics of the 13,56 MHz carrier. Since inductors are non-ideal
components and the self-resonant frequency of the second coil is around 400 MHz, we
propose to use a two staged filter.
The first stage has a corner frequency above 200 MHz and will reduce the harmonics at the
higher frequencies.
The second stage has a corner frequency below 10 MHz and will reject frequencies in the
lower frequency band.
The matching network follows the filter and adapts the power from the driver to the antenna.
The tuning consists of external capacitors and chip internal switches. In case the switches are
open, the antenna Voltage is directly applied to the input pin of the chip.
Since the expected Voltage of the Antenna can be high, additional capacitors for voltage
limitation can be applied. The AS3911 can accept voltages up to 30V on its antenna tuning
pins.
The input pins are being connected by a capacitive divider. The voltage on that pins shall be
less than 3.3 Volt.
Proprietary and Confidential
8
3.4.3 Capacitive wakeup
The capacitive wakeup consists of two pins that are each connected to an electrode and are
protected against ESD with a gas discharge element.
Since that pins can also be used as test outputs, an additional UFL connector is mounted.
4 Measurement
4.1
Current consumption
The measurement is being done across the AS3911 supply jumper P5.
AS3911 working condition
Current consumption in
mA
After startup
7,58
en=1, rx_en=0, tx_en=0
en=1, rx_en=1, tx_en=0
en=1, rx_en=1, tx_en=1
en=0, rx_en=0, tx_en=0, wu=1
14,97
150
0.002
4.2
Antenna stage
Used equipment:
Network Analyzer HP 8753C Network analyser
Parameter test set 85047A Test set
4.3
Measurement of the antenna Parameters
The parameters of the antenna are done in following sequence
1: Start with the measurement of the serial Inductance and the serial resistor at a frequency
that is far off the self-resonance of the antenna. The chosen frequency is 1 MHz
@ 1 MHz we get:
LPC = 940 nH
RDC = 470 mOhm
2. Measurement of the self-resonance (The point in which the impedance will be reel, all
reactance’s will be zero.
=> fres ~ 59 MHz
RP,CAR = 5000 Ohm
Using the inductance value that are being measured at 1 MHz, the resonance capacitor can be
calculated with the formula
1
1
C =
=
= 7,74pF
(2*Π * fres)2 * LPC (2*Π *59MHz)2 *940nH
The value of the parallel resistor has to be converted from the self-resonance for the working
frequency. The main reason for that conversion is the skin effect of the antenna, thus a
correction factor can be given by:
Proprietary and Confidential
9
fres
59
K =
=
= 2,085
ftune
13,56
Which will end up in Rp2 at fc= K*RDC
R
=
PC2
K
⋅
10,4 kΩ
≅
Finally
All components of the antenna are now known and a replacement for the antenna circuit can
be drawn.
The serial resistor of the coil can be converted with the approximation formula of the Q-
factor
ω
L
Rp
(ω
L)2
Q =
≈
⇒ Rp =
=14kOhm
Rs
ω
L
Rs
The complete resistor will thus be a parallel schematic of the resistor due to DC component
and the self-resonance component
Rp1* Rp2
Rpc =
≈ 6,02kOhm
Rp1+ Rp2
All components of the antenna are known and a model of the antenna can be given:
ꢀ
The values for the wanted resonance circuit are therefore:
RPC =6,02 kOhm
CPC= 7,74 pF
LPC= 940 nH
4.4
Determination of the Antenna resistor
The Antenna Q Factor can then be calculated as
RPC
RP
6,02kOhm
Q =
=
=
= 75
(
ω
L)
(ωL) 2*Π *13,56MHz *940nH
Proprietary and Confidential
10
Since the antenna works like a filter around it resonance frequency and the subcarrier is
848kHz apart from the carrier, the bandwidth and thus the Q factor need to be adapted. The
Bandwidth is defined based on the sub carrier frequency.
∆fres
848kHz
Q =
=
≈ 13
fres 13,56MHz
Since AS3911 can work due its excellent sensitivity in high Q environment, the Q factor can
be increased to values above 13 and for that board Q is set to 20.
And the parallel target resistor can then be calculate to
RT = Q*(ωL)
RT = 20*(2*13MHz*940nH) =1601Ohm
Taking the parasitic resistor RPC from the antenna into account, the physical assembled
resistor can be calculated to
RPC RT
6020*1601
RP =
=
= 2181Ω
RPC − RT 6020 −1601
The next available physical value is 2200 Ohm.
4.5
Matching of the driver
The matching is done from the driver resistor towards the antenna resistor.
The driver resistor can be assumed with 2 Ohm.
Since the antenna is being used differential, only half of the antenna shall be considered for
the matching.
Matching resistor on antenna side: RP=1090 Ohm
Antenna coil
LP=470nH
Driver
resistor
Matching
resistor
Antenne coil
EMC Filter Network
Matching network
Using the program smith.exe from Bern University of applied science, following matching
with physical available values is found.
Proprietary and Confidential
11
2 Ohms are being matched to 1220 Ohm.
According to the smith chart, the parallel capacitor shall be 89 pF. This capacitor is being
composed out of the parasitic capacitance of the antenna, the parasitic capacitance of the
tracks / voltage divider of the input and the tuning capacitor.
Capacitor
Value
pF
Note
Parasitic antenna capacitor
15,4
Measured value of 7,7 pF
needs to be multiplied by two
due to the differential stage
Capacitor divider (10 pF)
plus 2 pF parasitic on each
tuning inputs (4x2 pF)
Parasitic of the capacitive Assumed to be18
divider and tuning inputs
Tuning capacitor
Result
56
88
Half of the maximum tuning
capacitor bank
4.6
Verification of the Q factor in the time domain
The resonance circuit envelope can be calculated with an exponential function
Falling edge:
Proprietary and Confidential
12
2*Πfc
−t
−t
Q
U f = e τ = e
Rising edge:
2*Πfc
−t
−t
Q
Ur = 1− e τ = 1− e
Thus if the time constant (37% of the maximum amplitude) is known, the Q factor is
calculated to:
QB =
τ
*2*Π * fc
Measurement with Standard assembly of 2200 Ohm.
4.7
With TF=310 ns
With TR=205 ns
QR=26
QF=17
4.8
Layout recommendations
AS3911 is a high integrated device that allow easy layout. There are only a few layout rules to
consider.
Use a solid ground plan under the chip and use thermal via under the chip to dissipate the heat
of and enable a low ohmic connection of the exposed pad to the ground plane.
Take care that the decoupling capacitors of the LDO are close to the chip. Use thick wires for
the decoupling tracks and place the 10nF capacitor closest to the chip.
Use a symmetric layout for the antenna stage
Do not cross the digital lines with the analogue lines.
Take care on the signals VSN_RF, VSP_RF and the two output pins RFO1 and RFO2. These
pins build up the internal driver stage. Tracks on those four pins shall be short and ground
connections must be solid.
Proprietary and Confidential
13
4.9
PCB stack
The PCB stack is made of a two layer PCB with 1.6 mm core material and 35micro (43 micro
final ) copper.
4.10
Gerber Top
Proprietary and Confidential
14
4.11
Gerber Bottom
Proprietary and Confidential
15
4.12
Assembly Top
Proprietary and Confidential
16
4.13
Bill of Material
Part Info
Reference
Footprint
Producer
Distributor
Distributor Number
count
Integrated
Circuits (IC)
AS3911
AS1
U2
QFN32
austriamicrosystems
austriamicrosystems
Microchip
1
AS1360
SOT23
1
PIC27FJ64GB002
SMD resistor
10k
U3
QFN28_6x6
Digikey
Digikey
PIC24FJ64GA002T-
I/MLTR-ND
R1, R2, R4, R5, R0402
R7, R18, R20,
R100
Yageo
311-10KGRTR-ND
8
0R
R6,R29
R0402
Yageo
Digikey
Digikey
311-00JRTND
P220GTND
2
220R
R8, R9, R10, R11, R0402
R12, R13, R14,
R15, R16, R17
Panasonic-ECG
10
470R
R19, R23, R24, R0402
R25, R26
Stackpole
Electronics
Y
Digikey
RMCF0402JT470RTR-ND
5
27R
R21, R22
R0402
R0402
R0402
Digikey
Digike
Dgiy
311-27JRTR-ND
311-330JRTR-ND
311-2.2KJRTR-ND
2
1
1
330R
R27
Yag
Yage
2k2
R28
SMD capacitors
10u
C1,C4,C10
C5,C6
C0805
03
TDK Corporation
Digikey
445-1371-2-ND
3
1u
Taiyo Yuden
Yageo
Digikey
Digikey
587-2834-2-ND
311-1042-2-ND
2
6
10n
C7, C15, C18, C040
C24, C29, C30
100n
18p
C8, C9
C0402
AVX Cooration
rporation
Digikey
Digikey
478-1239-2-ND
445-1238-2-ND
2
4
C11, C12, C1C0402
C16
2u2
C14, C17, C21, C0603
C32, C33
TDK Corporation
Digikey
587-2983-2-ND
5
6p8
12p
100p
27p
C20, C34
C23, C35
C25
C0402
C02
040
402
TDK Corporation
Yageo
Digikey
Digikey
Digikey
Digikey
445-4887-2-ND
311-1016-2-ND
311-1024-2-ND
311-1019-2-ND
2
2
1
2
Yageo
C27, C36
Yageo
56p
C31, C37
C38, C43
C44, C47
C0402
C0402
C0402
Yageo
Yageo
Yageo
Digikey
Digikey
Digikey
311-1022-2-ND
311-1021-2-ND
311-1028-2-ND
2
2
2
47p
470p
330p
C5, C
C48C49
C0
C0402
C0603
C0603
C0603
C0603
Yageo
Digikey
Digikey
Digikey
Digikey
Digikey
311-1027-2-ND
445-1248-2-ND
445-5039-2-ND
445-1281-2-ND
399-1049-2-ND
2
2
1
2
2
120p
TDK Corporation
TDK Corporation
TDK Corporation
Kemet
6p8
100p
C51, C54
C52, C53
10p
SMuctors
10n
L4,L5
L0603
L0805
L0805
TDK Corporation
Murata
Digikey
Digikey
Digikey
445-1492-2-ND
490-5669-2-ND
587-1911-2-ND
2
2
5
20n
L7,L8
Ferritbead
SMD diodes
24V
L1, L2, L3, L6, L9
Taiyo Yuden
D1, D2, D4
D3
D0603_SUP
RESSOR
SOD323F
(SC-90)
Farnell
Digikey
1470613
3
1
Zener
Comchip
Technology
641-1068-2-ND
Proprietary and Confidential
17
SMD LED
LED_LUMEX
Oscillator
27.12MHz
D5,D6,D7,D8
Q1
Led_0402_L
umex
Kingbright Corp
Digikey
Digikey
754-1104-2-ND
490-5581-2-ND
4
1
Crystal FA- Murata
20H
40.0000MF1
5Z-AC3
Mechanical
components
USB_MINI_B
U1
SOCKET_S
MD_USB_M
INI
Hirose Electric
Digikey
Digikey
H2959TR-ND
1
Not Used
10u
C2,C3
Y1
C0603
TDK Corporation
445-4112-2-ND
2
1
8MHz
Crystal FA-
20H
40.0000MF1
5Z-AC3
Header 8H
P1, P2
P3, P4
HDR1X8
2
2
U
FL Socket
-
Surface Mount
Header 2
P5
HDR1X2
HDR1X2
HDR1X3
TESTPOINT
PIN1
1
2
1
1
4
8
MHDR1X2
Header 3
Plug
P6, P7
P8
T1
Plug
T2, T3, T4, T5
dnp
C19, C22, C26, C0402
C28, C39, C40,
C41, C42
dnp
R3
02
1
2
CSA20-141N DNP
U4, U5
6-080_M
Tolerance if not other specified
Capacitor NP0/COG
Capacitor X7R:
Capacitor Y5V:
Tantalum
2%
10%
+80% 20%
20%
Resistor
5%
Inductivity
5%
5
Version History
Version
100
Originator
tlu
Change log
Initial Version
Proprietary and Confidential
18
For further information please contact
The Wireless Business Line
Schloss Premstaetten
A-8141 Unterpremstaetten
AUSTRIA
Tel: +43-(0)3136-500-5473
FAX: +43-(0)3136-500-4141
Subject to change without notice
Proprietary and Confidential
19
更多>>
最新上传
- 打赏
- 30日榜单
-
21ic小能手 打赏10.00元 3天前
-
21ic小能手 打赏10.00元 3天前
-
cai0603 打赏3.00元 3天前
用户：CJQ_ENJOY
-
21ic小能手 打赏5.00元 3天前
-
21ic小能手 打赏10.00元 3天前
-
cai0603 打赏3.00元 3天前
用户：dongshao
-
21ic小能手 打赏5.00元 3天前
-
21ic小能手 打赏10.00元 3天前
-
21ic下载 打赏310.00元 3天前
用户：gsy幸运
-
21ic下载 打赏310.00元 3天前
用户：zhengdai
-
21ic下载 打赏310.00元 3天前
用户：小猫做电路
-
21ic下载 打赏310.00元 3天前
用户：liqiang9090
-
21ic下载 打赏270.00元 3天前
用户：kk1957135547
-
21ic下载 打赏160.00元 3天前
用户：w178191520
-
21ic下载 打赏160.00元 3天前
用户：w1966891335
-
21ic下载 打赏50.00元 3天前
用户：w993263495
-
21ic下载 打赏40.00元 3天前
用户：w993263495
-
21ic下载 打赏90.00元 3天前
用户：cooldog123pp
-
21ic下载 打赏30.00元 3天前
用户：sun2152
-
21ic下载 打赏40.00元 3天前
用户：xzxbybd
-
21ic下载 打赏40.00元 3天前
用户：铁蛋锅
-
21ic下载 打赏30.00元 3天前
用户：happypcb
-
21ic下载 打赏50.00元 3天前
用户：forgot
-
21ic下载 打赏10.00元 3天前
用户：xuzhen1
-
21ic下载 打赏20.00元 3天前
用户：wanglu6666
-
21ic下载 打赏5.00元 3天前
用户：人间留客
-
21ic下载 打赏5.00元 3天前
用户：jyxjiyixing
-
21ic下载 打赏5.00元 3天前
用户：akae_du
-
21ic下载 打赏5.00元 3天前
用户：ouyang_56
-
21ic小能手 打赏5.00元 3天前
-
21ic小能手 打赏5.00元 3天前
-
21ic小能手 打赏5.00元 3天前
-
21ic小能手 打赏5.00元 3天前
-
21ic小能手 打赏5.00元 3天前
-
xlhtracy 打赏10.00元 3天前
-
xlhtracy 打赏10.00元 3天前
-
21ic小能手 打赏5.00元 3天前
-
21ic小能手 打赏5.00元 3天前
-
xlhtracy 打赏5.00元 3天前
-
czmhcy 打赏1.00元 3天前
资料：bitboy
全部评论(0)