Test Setup
3
SNLU261A – August 2019 – Revised November 2019
Copyright © 2019, Texas Instruments Incorporated
TUSB2E22EVM-CAT User's Guide
2.2
TUSB2E22EVM-CAT - Bench Power
Bench power is used for power measurements and checking operation at voltage corners.
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3.3V power supply is supplied to J14_1
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1.8V power supply is supplied to J15_1
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Jumper J16 [1,2] is installed to route 3.3V to TUSB2E22
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SW2 is pulled high (SW 2 to 3) prior to power on / reset.
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5V power supply is supplied to J5_1 to provide VBUS on the USB ports.
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Jumpers J2 and J9 can be installed as needed if VBUS is to be provided to one of the USB ports
(host mode) or sensed from one of the ports (device mode)
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Jumpers not installed: J14, J15, J16[2,3]
NOTE:
The 1K ohm latch-up protection resistors, R28 and R27, will have a noticeable impact on
power measurements and should not be installed.
3
Board Layout
The TUSB2E22EVM-CAT was laid out with the following considerations:
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USB 2.0 signals impedance controlled 90 ohms differ/- 5%
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eUSB2 signals impedance controlled 45 ohms signal ended +/- 5%
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USB 2.0 and eUSB2 signal pairs routed with matched trace lengths and minimal vias.
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All other signals to be impedance controlled 45 ohms +/- 10% or 50 ohms +/- 10%
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Separate ground plane for TUSB2E22 connected by 0 ohm resistor, ground to ground vias added to
minimize parasitic inductance.
General information about the PCB is provided below:
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Finished board thickness: .062 +/- 10% - necessary for socket
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Copper weight: 1oz start internal, 1/2 oz start external
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Laminate material: FR4 Polyclad 370 or equivalent
A six layer stack-up was used for the EVM to account for the small BGA breakout in addition to some
added lab use only test capabilities. TUSB2E22 would typically be designed onto a 4 layer board.
Drill notes on board stack up:
1. L1 -L2 (laser drill) used for small pitch BGA break out
2. L2 - L5 (mechanical drill) completes the small pitch BGA breakout
