NXP Semiconductors

UM12262

FRDM-IMX91 Board User Manual

The CAN interface circuit includes the split termination RC filter (62Ω + 56pF) for noise rejection and signal

integrity. The switch SW4 is provided for enabling/disabling the RC filter. For SW4 detail, see Section 1.7.

The HS-CAN transceiver and header are described in Table 18.

Part identifier

Manufacturing part

number

Description

U741

TJA1051T/3

High-speed CAN transceiver. Provides an interface between a CAN

protocol controller and the physical two-wire CAN bus.

P12

Not applicable

10-pin 2x5 2.54 mm connector (P12). It is connected to the CAN bus and

allows external connection with the bus.

Note: Table 10 explains pinout for the 10-pin 2x5 2.54 mm connector

P12.

Table 18. High-speed CAN transceiver and header

Note: For details about TJA1051, see TJA1051 data sheet at nxp.com.

2.13 USB interface

The i.MX 91 applications processor features two USB 2.0 controllers, with two integrated USB PHYs. On the

FRDM-IMX91 board, one is used for the USB2.0 Type-C Port (P2) and the other is used for USB2.0 Type-A

Port (P17).

Table 19 describes the USB ports available on the board.

Part identifier USB port type

Description

P2

USB2.0 Type-C

Connects to full-speed USB host and device controller (USB 1) of target

processor.

It can operate as a device or host. The USBC_VBUS signal controls the

VBUS drive for the USB port.

P17

USB2.0 Type-A

Connects to full-speed USB host and device controller (USB 2) of target

processor. It can operate as a device or host. The USB2_VBUS signal

controls the VBUS drive for the USB port.

The USB2_DP and USB2_DN signals from the USB2 controller of the target

processor connect to USB2 Type A port (P17) by default. These signals can

be connected to M.2 card connecter (P6) by solder/DNP R2803, R2804,

R2806, R2807.

P1

USB Type-C PD

It is used for power only. It does not support USB data transfer. It is the only

power supply port therefore it must always be supplied for system power.

P16

USB Type-C

It is used for system debug purpose. For detail, see the system debug

section.

Table 19. USB ports

2.14 Ethernet

The i.MX 91 processor supports two Gigabit Ethernet controllers (capable of simultaneous operation) with

support for Energy-Efficient Ethernet (EEE), Ethernet AVB, and IEEE 1588.

The Ethernet subsystem of the board is provided by the Motorcomm YT8521SH-CA Ethernet transceivers

(U713, U716) which support RGMII and connect to RJ45 connectors (P3, P4). The Ethernet transceivers

(or PHYs) receive standard RGMII Ethernet signals from i.MX 91. The RJ45 connectors integrate Magnetic

transformer inside, so they can be directly connected to Ethernet transceivers (or PHYs).

UM12262

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User manual

Rev. 3.0 — 22 April 2025

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