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AM263P4-Q1: AM263P4 MCU damage to ESD

Jayakeerthana P
Intellectual 395 points

Part Number: AM263P4-Q1
Other Parts Discussed in Thread: AM263P4, , TPD4E02B04

Hi team,
  We are using the AM263P4 microcontroller in our custom board. Over the past two months, more than four MCUs have been damaged, and ESD is suspected to be the primary cause.

Apart from using ESD wrist straps and working in an ESD-protected area, we would like to understand what additional measures can be implemented in our hardware design to protect the MCU from ESD damage.

Could you please help us with the following queries?

  1. What additional design-level protection measures can be implemented to prevent ESD damage to the AM263P4?

  2. What are the possible causes of MCU damage due to ESD during assembly, testing, programming, or normal operation?

  3. Are there any specific precautions recommended for the power supply, reset, boot, JTAG, and UART interfaces to prevent ESD-related damage?

  4. Could you please share any relevant application notes or design guidelines for improving ESD robustness in our custom board?

Your recommendations would help us identify the root cause and prevent further MCU failures.

Regards
Jayakeerthana P

  • 0
    TI__Mastermind 40033 points

    Hi Jayakeethana,

    1. Design-level protection: The AM263P4-Q1 carries a 2 kV HBM device-level ESD rating, which is below a ±4 kV connector-level requirement, so TI's guidance is to add external TVS/clamp protection on any exposed ADC and GPIO signals, and to keep injected current at 20 mA or below (note: the 100 mA figure is a JEDEC latch-up rating, not a design target) 1. For USB-connected interfaces, place suppressors directly on the signal traces as close as possible to the connector (avoiding stubs) and tie the connector shield to chassis ground; TI's own EVM uses the TPD4E02B04 for this 2.

    2. Causes of ESD damage: General ESD events occur when a charged person, IC, or machine contacts the device, or an electrostatic field induces breakdown 3. Internal ESD structures are intended for pre-assembly handling only, not sustained board-level protection, so externally connected I/O needs added protection 4. During assembly/test, recommended controls include PCB ionization, grounded dissipative pick-and-place tooling, and dissipative test fixtures/pogo pins 5.

    3. Power/reset/boot/JTAG/UART precautions: PORz should stay low until both the 1.2 V core and 3.3 V rails reach nominal voltage, with SOP pins held in their boot-latch state until supplies stabilize 6. Power rails ramping too quickly can inadvertently trigger internal ESD structures and cause excess current draw, and non-fail-safe inputs (including JTAG/GPIO) should not see external signals before their supply rails are valid 7. A removable/depopulatable JTAG/trace header is recommended for production boards 8. No AM263P4-Q1-specific external ESD component or layout guidance for the UART/JTAG/reset connectors themselves was found in the retrieved material.

    4. App notes: The custom-board bring-up note directs designers to the separate "AM26x Hardware Design Guidelines" application note for full design-phase recommendations 9; the complete content of that guideline (connector-level ESD, grounding, and layout rules) was not retrieved in this search.

    Clarifications that would sharpen the analysis:
    - Which specific connectors/interfaces on your custom board are exposed to human contact or external cables (power input, JTAG header, UART, reset switch)? This determines where external TVS protection is actually required.
    - Are the failures occurring at a specific assembly/test/field stage, or intermittently during operation? Pinpointing the stage would let us match it against the assembly/test vs. operation-phase causes above.
    - Do you have the specific TVS/clamp part numbers currently used (if any) on these interfaces, so we can verify they meet the ±4 kV/20 mA targets?

    1. E2E: AM263P4-Q1 ESD clamping diodes on ADC inputs and GPIOs
    2. AM26x Hardware Design Guidelines - USB ESD
    3. E2E: FAQ - What is ESD immunity per IEC 61000-4-2
    4. E2E: AM2434 pins ESD protection and maximum allowed voltages
    5. TI Errata/App note on ESD handling controls
    6. AM263P4-Q1 Datasheet - Power-on sequencing
    7. E2E: AM625/AM64x/AM243x design recommendations - core supplies
    8. AM26x Hardware Design Guidelines - JTAG header
    9. AM26x Custom Board Bring-up Application Note

    Best Regards,

    Zackary Fleenor