22 ELECTRICAL CHARACTERISTICS
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
22-15
(Rev. 2.00)
22.14 R/F Converter (RFC) Characteristics
R/F converter characteristics change depending on conditions (board pattern, components used, etc.). Use these
characteristic values as a reference and perform evaluation using the actual printed circuit board.
Unless otherwise specified: V
DD
= 1.8 to 5.5 V, V
SS
= 0 V, Ta = -40 to 85 °C
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Reference/sensor oscillation frequency f
RFCLK
1
–
1,000
kHz
Reference/sensor oscillation frequency
IC deviation
D
f
RFCLK/
D
IC Ta = 25 °C
*
1
-40
–
40
%
Reference resistor/resistive sensor
resistance
R
REF,
R
SEN
10
–
-
k
W
Reference capacitance
C
REF
100
–
–
pF
Time base counter clock frequency
f
TCCLK
–
–
4.2
MHz
High level Schmitt input threshold
voltage
V
T+
0.5
×
V
DD
–
0.8
×
V
DD
V
Low level Schmitt input threshold
voltage
V
T-
0.2
×
V
DD
–
0.5
×
V
DD
V
Schmitt input hysteresis voltage
D
V
T
120
–
–
mV
R/F converter operating current
I
RFC
C
REF
= 1,000 pF, R
REF
/R
SEN
= 100 k
W
,
Ta = 25 °C, V
DD
= 3.6 V
–
200
350
µA
*
1 In this characteristic, unevenness between production lots, and variations in measurement board, resistances and capacitances
are taken into account.
Waveforms for external clock input mode
RFINn
1/f
RFCLK
V
T+
V
T+
V
T-
1/f
RFCLK
V
T+
V
T+
V
T-
RFC reference/sensor oscillation frequency-
RFC reference/sensor oscillation frequency-
resistance characteristic
capacitance characteristic
C
REF
= 1,000 pF, Ta = 25 °C, Typ. value
R
REF
/R
SEN
= 100 k
W
, Ta = 25 °C, Typ. value
1,000
100
10
1
0.1
f
RFCLK
[kHz]
V
DD
3.6 V
1.8 V
∆
f
RFCLK
/
∆
IC
1
10
100
1,000
10,000
R
REF
/R
SEN
[k
Ω
]
10
1,000
100
10
1
0.1
100
1,000
10,000
100,000
C
REF
[pF]
f
RFCLK
[kHz]
V
DD
3.6 V
1.8 V
∆
f
RFCLK
/
∆
IC