Datasheet

AFE4490
SBAS602F –DECEMBER 2012–REVISED OCTOBER 2013 www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
Minimum and maximum specifications are at T
A
= –40°C to +85°C. Typical specifications are at +25°C.
All specifications are at RX_ANA_SUP = RX_DIG_SUP = 3 V, TX_CTRL_SUP = LED_DRV_SUP = 5 V, stage 2 amplifier
disabled, and f
CLK
= 8 MHz, unless otherwise noted.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
DIAGNOSTICS
EN_SLOW_DIAG = 0
Start of diagnostics after the DIAG_EN register
bit is set. 8 ms
End of diagnostic indicated by DIAG_END going
high.
Duration of diagnostics state machine
EN_SLOW_DIAG = 1
Start of diagnostics after the DIAG_EN register
bit is set. 16 ms
End of diagnostic indicated by DIAG_END going
high.
Open fault resistance > 100 kΩ
Short fault resistance < 10 kΩ
Diagnostics current During diagnostics mode < 100 µA
INTERNAL OSCILLATOR
With an 8-MHz crystal connected to the XIN and
f
CLKOUT
CLKOUT frequency 4 MHz
XOUT pins
DC
CLKOUT
CLKOUT duty cycle 50%
With an 8-MHz crystal connected to the XIN and
Crystal oscillator start-up time 200 µs
XOUT pins
EXTERNAL CLOCK
Maximum allowable external clock jitter 50 ps
External clock input frequency ±10% 8 MHz
Voltage input high (V
IH
) 0.75 × RX_DIG_SUP V
External clock input voltage
Voltage input low (V
IL
) 0.25 × RX_DIG_SUP V
External clock input current 1 µA
TIMING
Wake-up time from complete power-down 1000 ms
Wake-up time from Rx power-down 100 µs
Wake-up time from Tx power-down 1000 ms
t
RESET
Active low RESET pulse duration 1 ms
DIAG_END pulse duration at diagnostics CLKOUT
t
DIAGEND
4
completion cycles
CLKOUT
t
ADCRDY
ADC_RDY pulse duration 1
cycles
DIGITAL SIGNAL CHARACTERISTICS
AFE_PDN, SPI CLK, SPI SIMO, SPI STE,
V
IH
Logic high input voltage 0.75 × RX_DIG_SUP V
RESET
AFE_PDN, SPI CLK, SPI SIMO, SPI STE,
V
IL
Logic low input voltage 0.25 × RX_DIG_SUP V
RESET
I
IN
Logic input current Digital inputs at V
IH
or V
IL
0.1 µA
DIAG_END, LED_ALM, PD_ALM, SPI SOMI,
V
OH
Logic high output voltage RX_DIG_SUP – 0.1 V
ADC_RDY, CLKOUT
DIAG_END, LED_ALM, PD_ALM, SPI SOMI,
V
OL
Logic low output voltage 0.1 V
ADC_RDY, CLKOUT
PIN LEAKAGE CURRENT
Pin leakage current To GND and supply 1 nA
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