20-2
Seiko Epson Corporation
S1C31D50 TECHNICAL MANUAL
(Rev. 1.00)
20.2.
Input/Output Pins and External Connections
20.2.1.
List of Input/Output Pins
Table 20.2.1.1 lists the RFC pins.
Table 20.2.1.1 List of RFC Pins
Pin name
I/O
*
Initial status
*
Function
SENB
n
A
Hi-Z
Sensor B oscillation control pin
SENA
n
A
Hi-Z
Sensor A oscillation control pin
REF
n
A
Hi-Z
Reference oscillation control pin
RFIN
n
A
VSS
RFCLK input or oscillation control pin
RFCLKO
n
O
Hi-Z
RFCLK monitoring output pin
RFCLK is output to monitor the oscillation frequency.
* Indicates the status when the pin is configured for the RFC.
If the port is shared with the RFC pin and other functions, the RFC input/output function must be
assigned to the port before activating the RFC. F
or more information, refer to the “I/O Ports” chapte
r.
Note:
The RFIN
n
pin goes to V
SS
level when the port is switched. Be aware that large current may flow if the
pin is biased by an external circuit.
20.2.2.
External Connections
The figures below show connection examples between the RFC and external sensors. For the oscillation
mode and external clock input mode,
refer to “Operating Mode
.
”
Figure 20.2.2.1 Connection Example in Resistive Sensor DC Oscillation Mode
Figure 21.2.2.2 Connection Example in Resistive Sensor AC Oscillation Mode
SENB
n
SENA
n
REF
n
RFIN
n
R
SEN2
R
SEN1
R
REF
C
REF
S1C31 RFC
R
REF
: Reference resistor
R
SEN1
: Resistive sensor (DC bias)
R
SEN2
: Resistive sensor (DC bias)
C
REF
: Reference capacitor
SENB
n
SENA
n
REF
n
RFIN
n
R
SEN1
R
REF
C
REF
S1C31 RFC
R
REF
: Reference resistor
R
SEN1
: Resistive sensor (AC bias)
C
REF
: Reference capacitor
Summary of Contents for S1C31D50
Page 461: ...25 1 Seiko Epson Corporation S1C31D50 TECHNICAL MANUAL Rev 1 00 25 Package TQFP12 48PIN ...
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Page 463: ...25 3 Seiko Epson Corporation S1C31D50 TECHNICAL MANUAL Rev 1 00 TQFP14 80PIN ...
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