USB3320 Datasheet, PDF (62/70 Pages) Microchip Technology – Highly Integrated Full Featured Hi-Speed USB 2.0 ULPI Transceiver

USB3320
8.2 Reference Designs
Microchip has generated reference designs for connecting the USB3320 to SOCs with a ULPI port. Please contact the
Microchip sales office for more details.
8.3 ESD Performance
The USB3320 is protected from ESD strikes. By eliminating the requirement for external ESD protection devices, board
space is conserved, and the board manufacturer is enabled to reduce cost. The advanced ESD structures integrated
into the USB3320 protect the device whether or not it is powered up.
8.3.1 HUMAN BODY MODEL (HBM) PERFORMANCE
HBM testing verifies the ability to withstand the ESD strikes like those that occur during handling and manufacturing,
and is done without power applied to the IC. To pass the test, the device must have no change in operation or perfor-
mance due to the event. All pins on the USB3320 except the REFCLK, SPK_L, and SPK_R pins provide ±8kV HBM
protection, as shown in Table 4-10.
8.3.2 EN/IEC 61000-4-2 PERFORMANCE
The EN/IEC 61000-4-2 ESD specification is an international standard that addresses system-level immunity to ESD
strikes while the end equipment is operational. In contrast, the HBM ESD tests are performed at the device level with
the device powered down.
Microchip contracts with Independent laboratories to test the USB3320 to EN/IEC 61000-4-2 in a working system.
Reports are available upon request. Please contact your Microchip representative, and request information on 3rd party
ESD test results. The reports show that systems designed with the USB3320 can safely provide the ESD performance
shown in Table 4-10 without additional board level protection.
In addition to defining the ESD tests, EN/IEC 61000-4-2 also categorizes the impact to equipment operation when the
strike occurs (ESD Result Classification). The USB3320 maintains an ESD Result Classification 1 or 2 when subjected
to an EN/IEC 61000-4-2 (level 4) ESD strike.
Both air discharge and contact discharge test techniques for applying stress conditions are defined by the EN/IEC
61000-4-2 ESD document.
8.3.3 AIR DISCHARGE
To perform this test, a charged electrode is moved close to the system being tested until a spark is generated. This test
is difficult to reproduce because the discharge is influenced by such factors as humidity, the speed of approach of the
electrode, and construction of the test equipment.
8.3.4 CONTACT DISCHARGE
The uncharged electrode first contacts the USB connector to prepare this test, and then the probe tip is energized. This
yields more repeatable results, and is the preferred test method. The independent test laboratories contracted by Micro-
chip provide test results for both types of discharge methods.
DS00001792B-page 62
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