1 / 4

Standard setup with Channel-Pair

DUT Transmitter. 50 Ω. Driver termination Vterm = Vocm. 50 Ω. Driver termination Vterm = Vocm. Voh. 50 Ω. Vocm. 50 Ω. Vol. Standard setup with Channel-Pair. TX setup: Device to Tester. Pin Configuration: Two tester channels per LVDS pair Driver termination to common mode

selima
Download Presentation

Standard setup with Channel-Pair

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DUT Transmitter 50Ω Driver termination Vterm = Vocm 50Ω Driver termination Vterm = Vocm Voh 50Ω Vocm 50Ω Vol Standard setup with Channel-Pair TX setup: Device to Tester Pin Configuration: • Two tester channels per LVDS pair • Driver termination to common mode • Maintains 50/100 Ohm requirement Levels: • Vol = Vocm - Vod/2 • Voh = Vocm + Vod/2 • Vt = Vocm • Driver termination to common mode voltage for functional tests • 50 Ohm term to common mode on both channels is similar to 100 Ohm cross term • No relays and additional resistors on the DUT-board are needed • Termination can be switched off by SW for DC measurements • See next page how to measure common mode voltage... Agilent Restricted

  2. ‘Classic’ way for DC common mode measurement • Run a preconditioning pattern to bring the device outputs to a defined state • Measure the output voltages for ‘one’ and ‘zero’ on both lines of the pair • Calculate and check the common mode voltage for both cases • Can be implemented with testflow variables, as a userprocedure or a testmethod Preconditioning Measurement Preconditioning Measurement Calculation & Check VOp_0 VOn_1 VOCM_0 VOCM_1 PASS/FAIL VOn_0 VOp_1 GND • VOCM_0 = Vop_0 - Von_0 • VOCM_1 = Von_1 - Vop_1 Agilent Restricted

  3. Solution proposal #1: Relays to switch-in resistors Tester Channel 50 • Switch in the resistors only when they are required • Run high-speed functional test with standard driver termination to Vcom • Minimize Reflections on the ‘open’ line by keeping the connection path very short Device Driver 50 Tester Channel 10 K 50 50 pF 50 Tester Channel 50 Loadboard Agilent Restricted

  4. Solution proposal #2: Relays to switch-in resistors Tester Channel 50 • Switch in the resistors only when they are required • Run high-speed functional with standard driver termination to Vcom • No ‘open ends’ in the relays for functional measurement Device Driver 50 Tester Channel 10 K 50 50 pF 50 Tester Channel 50 Loadboard Agilent Restricted

More Related