Datasheet
Electrical characteristics
i.MX 8M Dual / 8M QuadLite / 8M Quad Applications Processors Data Sheet for Industrial Products, Rev. 0, 01/2018
NXP Semiconductors 33
Table 33 shows the AC parameters for clock I/O.
3.7 Output buffer impedance parameters
This section defines the I/O impedance parameters of the i.MX 8M Dual / 8M QuadLite / 8M Quad
processors for the following I/O types:
• Double Data Rate I/O (DDR) for LPDDR4, DDR4, and DDR3L modes
• Differential I/O (CLKx)
• USB battery charger detection open-drain output (USB_OTG1_CHD_B)
NOTE
DDR I/O output driver impedance is measured with “long” transmission
line of impedance Ztl attached to I/O pad and incident wave launched into
transmission line. Rpu/Rpd and Ztl form a voltage divider that defines
specific voltage of incident wave relative to OVDD. Output driver
impedance is calculated from this voltage divider (see Figure 6).
Table 33. I/O AC parameters of LVDS pad
Symbol Parameter Test conditions Min Typ Max Unit Notes
Tphld Output Differential propagation delay high to low Rload = 100 between padp
and padn,
Cload = 2pF, at 125 °C, TYP, 1.62
V OVDD, and 0.9 V VDDI
— — 0.92 ns
1
1
At TYP, 125 °C, 1.62 V OVDD, and 0.9 V VDDI. Measurement levels are 50 - 50%. Output differential signal measured.
Tplhd Output Differential propagation delay low to high — — 0.92
Ttlh Output Transition time low to high — — 0.58
2
2
At TYP, 125 °C, 1.62 V OVDD, and 0.9 V VDDI. Measurement levels are 20 - 80%. Output differential signal measured.
Tthl Output Transition time high to low — — 0.73
Tphlr Input Differential propagation delay high to low Rload = 100
between padp
and padn, at 125 °C, TYP, 1.62 V
OVDD, and 0.9 V VDDI
— — 0.83 ns
3
3
At TYP, 125 °C, 1.62 V OVDD, and 0.9 V VDDI. Measurement levels are 50 - 50%.
Tplhr Input Differential propagation delay low to high — — 0.83
Ttx Transmitter startup time (ipp-obe low to high) — — — 40 ns
4
4
TX startup time is defined as the time taken by transmitter for settling after its ipp_obe has been asserted. It is to stabilize the
current reference. Functionality is guaranteed only after the startup time.
F Operating frequency — — 600 1000 MHz —