Datasheet

Electrical characteristics
i.MX 8QuadXPlus and 8DualXPlus Automotive and Infotainment Applications Processors, Rev. 0, 11/2018
PRELIMINARY NXP Semiconductors20
4.1.4 External clock sources
Each processor has two external input system clocks: a low frequency (RTC_XTALI) and a high frequency
(XTALI).
The RTC_XTALI is used for real time functions. It supplies the clock for real time clock operation and for
slow-system and watchdog counters. The clock input can be connected to either an external oscillator or a
crystal using the internal oscillator amplifier.
The system clock input XTALI is used to generate the main system clock. It supplies the PLLs and other
peripherals. The system clock input requires a crystal using the internal oscillator amplifier.
The PCIe oscillator can be sourced internally or input to the chip. In both cases, it is a 100 MHz nominal
clock using HCSL signaling to provide the PCIe reference clock.
The following table shows the interface frequency requirements.
Power supplies that shall be connected to output of an embedded LDO
VDD_TMPR_CSI_1P8_3P3 N/A 1.80 V Shall be internally
connected to
VDD_SNVS_LDO_1P8_
CAP when used as a
tamper pin. In CSI mode
use an external 1.8 V
supply. In this case,
follow the 1.8 V I/O
specification above.
VDD_USB_OTG_1P0 N/A 1.00 V Shall be externally
connected to
VDD_USB_SS3_LDO_1
P0_CAP
Junction temperature
Junction temperature -40 125
°C—
1
Voltage ranges are defined to group as many supplies as possible. Some supplies may have a wider range than listed here.
Table 7. External Input Clock Frequency
Parameter Description Symbol Min Typ Max Unit
RTC_XTALI Oscillator
1,2
1
External oscillator or a crystal with internal oscillator amplifier.
f
ckil
—32.768
3
/32.0 kHz
XTALI Oscillator
4,2
f
xtal
—24MHz
PCIe oscillator
5
f
100M
—100MHz
Frequency accuracy ±300 ppm
Table 6. Operating ranges
1
(continued)
Symbol Description Mode Min Typ Max Unit Comments