Datasheet

Electrical characteristics
i.MX RT1015 Crossover Processors Data Sheet for Consumer Products, Rev. 0.1, 03/2019
NXP Semiconductors 17
4.1.4 External clock sources
Each i.MX RT1015 processor has two external input system clocks: a low frequency (RTC_XTALI) and
a high frequency (XTALI).
The RTC_XTALI is used for low-frequency functions. It supplies the clock for wake-up circuit,
power-down real time clock operation, and slow system and watch-dog counters. The clock input can be
connected to either external oscillator or a crystal using internal oscillator amplifier. Additionally, there is
an internal ring oscillator, which can be used instead of the RTC_XTALI if accuracy is not important.
The system clock input XTALI is used to generate the main system clock. It supplies the PLLs and other
peripherals. The system clock input can be connected to either external oscillator or a crystal using internal
oscillator amplifier.
Table 11 shows the interface frequency requirements.
The typical values shown in Table 11 are required for use with NXP SDK to ensure precise time keeping
and USB operation. For RTC_XTALI operation, two clock sources are available.
• On-chip 40 kHz ring oscillator—this clock source has the following characteristics:
— Approximately 25 µA more Idd than crystal oscillator
— Approximately ±50% tolerance
— No external component required
Temperature Operating Ranges
Junction
temperature
Tj Standard
Commercial
0—95
o
C See the application note, i.MX
RT1015 Product Lifetime Usage
Estimates for information on
product lifetime (power-on years)
for this processor.
1
Applying the maximum voltage results in maximum power consumption and heat generation. NXP recommends a voltage set
point = (V
min
+ the supply tolerance). This result in an optimized power/speed ratio.
2
Applying the maximum voltage results in shorten lifetime. 3.6 V usage limited to < 1% of the use profile. Reset of profile limited
to below 3.49 V.
3
In setting VDD_SNVS_IN voltage with regards to Charging Currents and RTC, refer to the i.MX RT1015 Hardware
Development Guide (IMXRT1015HDG).
Table 11. 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.
2
The required frequency stability of this clock source is application dependent. For recommendations, see the Hardware
Development Guide for i.MX RT1015 Crossover Processors (IMXRT1015HDG).
f
ckil
—32.768
3
/32.0
3
Recommended nominal frequency 32.768 kHz.
—kHz
XTALI Oscillator
2,4
4
External oscillator or a fundamental frequency crystal with internal oscillator amplifier.
f
xtal
—24—MHz
Table 9. Operating ranges (continued)