AX−SFUS, AX−SFUS−API
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8
Table 5. LOGIC
Symbol Description Condition Min Typ Max Units
Digital Inputs
V
T+
Schmitt trigger low to high threshold point
VDD_IO = 3.3 V
1.55 V
V
T−
Schmitt trigger high to low threshold point 1.25 V
V
IL
Input voltage, low 0.8 V
V
IH
Input voltage, high 2.0 V
V
IPA
Input voltage range, GPIO[3:0] −0.5 VDD_IO V
V
IPBC
Input voltage range, GPIO[9:4], UARTRX −0.5 5.5 V
I
L
Input leakage current −10 10
mA
R
PU
Programmable Pull−Up Resistance 65
kW
Digital Outputs
I
OH
Output Current, high
Ports GPIO[9:0], UARTTX, TXLED, RXLED,
TXLED, CPULED
V
OH
= 2.4 V 8 mA
I
OL
Output Current, low
GPIO[9:0], UARTTX, TXLED, RXLED, TXLED,
CPULED
V
OL
= 0.4 V 8 mA
I
OZ
Tri−state output leakage current −10 10
mA
AC Characteristics
Table 6. TCXO REFERENCE INPUT
Symbol Description Condition Min Typ Max Units
f
TCXO
TCXO frequency A passive network between the TCXO output
and the pins CLKP and CLKN is required.
For detailed TCXO network recommendations
depending on the TCXO output swing refer to
the AX5043 Application Note: Use with a
TCXO Reference Clock.
For TCXO recommendations see the
AX−SFUS Application Note: Sigfox Compliant
Reference Design
48 MHz
Table 7. TRANSMITTER
Conditions for transmitter specifications unless otherwise specified with the antenna network from AX−SFUS Application Note: Sigfox
Compliant Reference Design and at 902.2 MHz.
Symbol Description Condition Min Typ Max Units
SBR Signal bit rate 100 bps
PTX Highest Transmitter output power AT$CW=902200000,1,24 24 dBm
dTX
temp
Transmitter power variation vs.
temperature
−40°C to +85°C ±0.5 dB
dTX
Vdd
Transmitter power variation vs. VDD_IO 1.8 to 3.6 V ±0.5 dB
PTX
harm2
Emission @ 2
nd
harmonic −51
dBc
PTX
harm3
Emission @ 3
rd
harmonic −63
PTX
harm4
Emission @ 4
th
harmonic −84
