Datasheet
i.MX 8M Dual / 8M QuadLite / 8M Quad Applications Processors Data Sheet for Industrial Products, Rev. 0, 01/2018
26 NXP Semiconductors
Electrical characteristics
3.4 On-chip oscillators
3.4.1 OSC25M and OSC27M
A 25 MHz oscillator is used as the primary clock source for the PLLs to generate the clock for the CPU,
BUS, and high-speed interfaces. For fractional PLLs, the 25 MHz clock from the oscillator can be used as
the PLL reference clock directly.
A 27 MHz oscillator is used as the reference clock for HDMI PHY. It can also be used as the alternative
source for the fractional PLLs.
Table 20 lists the electrical specifications of this oscillator when loaded with an NX5032GA 40 MHz
crystal unit at 40 MHz frequency. All values are valid only for the device TJ operating specification of -40
o
C to 125
o
C.
ARM_PLL Clock output range 800 MHz ~1.6 GHz
Reference clock 25 MHz
Lock time 50 s
DRAM_PLL Clock output range 400 MHz–800 MHz
Reference clock 25 MHz
Lock time 70 s
GPU_PLL Clock output range 800 MHz ~1.6 GHz
Reference clock 25 MHz
Lock time 50 s
VPU_PLL Clock output range 400 MHz ~ 800 MHz
Reference clock 25 MHz
Lock time 50 s
Table 20. Electrical specification of oscillator @ 1.8 V
Parameter Min Typ Max Unit
Voltage swing on external pin
1
1
The start-up time is dependent upon crystal characteristics, board leakage, etc.; high ESR and excessive capacitive loads can
cause long start-up time.
250 — 800 mV
Power consumption (analog
supply RMS current in OSC
mode)
2, 3
—— 4mA
Start-up time
1,
2
—— 2ms
Table 19. PLL electrical parameters (continued)
PLL type Parameter Value