GND
1500pF
1500pF
1200pF
1200pF
10pF
680pF
100pF 220pF
680pF
150nH
330nH
GND
GND
27pF
GND
GND
GND
2.2uF
0.01uF
2.2uF
0.01uF
GND
GND
2.2uF
0.01uF
GND
2.2uF
0.01uF
GND
27pF
GND
27pF
GND
1.5uH
68pF
GND
12pF
12pF
6.8k
GND
GND
10k
GND
GND
47k
0.1uF
100R
GND
GND
MC-921
GND
0
0
SMA-142-0701-801/806
GND
GND
2.2uF
0.01uF
GND
057-014-2
C2
C3
C4
C5
C6
C7
C10
C
8
C9
L1
L2
C11
C16
C15
C20
C19
C18
C17
C22
C21
C23
C24
L3
C14
C13
C12
R1
TCK
TMS
P4.0/TB0
P4.1/TB1
P4.2/TB2
P4.3/TB0
P4.4/TB1
P4.5/TB2
P4.6/TBOUTH/ACLK
P4.7/TBCLK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
29
30
31
32
33
34
35
36
37
38
TP
39
40
R6
R5
C1
R4
X2
R2
R3
GND1
2
IN
1
GND2
4
OUT
3
X3
V
D
D
_
X
3
2
O
S
C
_
IN
3
1
O
S
C
_
O
U
T
3
0
V
S
S
_
D
2
9
E
N
2
8
S
Y
S
_
C
L
K
2
7
D
A
T
A
_
C
L
K
2
6
E
N
2
2
5
I/O_7
24
I/O_6
23
I/O_5
22
I/O_4
21
I/O_3
20
I/O_2
19
VDD_A
1
VIN
2
VDD_PA
4
TX_OUT
5
VSS_PA
6
VDD_RF
3
I/O_1
18
I/0_0
17
B
A
N
D
_
G
A
P
11
V
D
D
_
I/
O
1
6
V
S
S
_
A
1
5
M
O
D
1
4
IRQ
1
3
A
S
K
/O
O
K
1
2
VSS_RX
7
RX_IN1
8
V
S
S
1
0
RX
_IN2
9
GND(PAD)
33
C25
C26
X4-1
X4
-2
X4-3
X4
-4
X4-5
X4
-6
X4-7
X4
-8
X4-9
X4
-10
X4-11
X
4-12
X4-13
X
4-14
SYS_CLK
S
Y
S
_
C
L
K
DATA_CLK
D
A
T
A
_
C
L
K
VIN
V
IN
IRQ
IRQ
M
O
D
MOD
V
D
D
_
X
VDD_X
V
D
D
_
X
RST_NMI
RST_NMI
RST_NMI
TCK
TCK
TMS
TMS
TDI
TDI
TDO/TDI
TDO/TDI
VCC
VCC
VCC
VCC
VCC
RXD
TXD
ASK/OOK
A
S
K
/O
O
K
E
N
EN
OSC_OUT
O
S
C
_
O
U
T
O
S
C
_
IN
OSC_IN
P3.0
P3.0
P3.2
P3.2
P3.1
P3.1
P3.6
P3.7
P4.2
P4.2
JTAG
(+2.7VDC - 5.5VDC)
TRF7964A
SLOS787H – MAY 2012 – REVISED APRIL 2014
7.2
TRF7964A Reader System Using SPI With SS Mode
7.2.1
General Application Considerations
shows the TRF7964A application schematic optimized for both ISO15693 and ISO14443
systems using the Serial Port Interface (SPI). Short SPI lines, proper isolation of radio frequency lines,
and a proper ground area are essential to avoid interference. The recommended clock frequency on the
DATA_CLK line is 2 MHz.
shows matching to a 50-
Ω
port, which allows connecting to a properly matched 50-
Ω
antenna
circuit or RF measurement equipment (for example, a spectrum analyzer or power meter).
7.2.2
Schematic
shows a sample application schematic for SPI with an SS mode MCU interface.
Figure 7-2. Application Schematic – SPI With SS Mode MCU Interface
An MSP430F2370 (32KB Flash, 2KB RAM) is shown in
. Minimum MCU requirements depend
on application requirements and coding style. If only one ISO protocol or a limited command set of a
protocol needs to be supported, MCU Flash and RAM requirements can be significantly reduced and user
should be aware that recursive inventory and anticollision commands require more RAM than single
slotted operations. For example, current reference firmware for ISO15693 (with host interface) is
approximately 8KB, using 512B RAM and for all supported protocols (also with same host interface) the
reference firmware is approximately 12KB and uses a minimum of 1KB RAM. An MCU capable of running
its GPIOs at 13.56 MHz is required for Direct Mode 0 operations.
Copyright © 2012–2014, Texas Instruments Incorporated
Application Schematic and Layout Considerations
69
Product Folder Links:
