17W system-level power supply reference design for automotive infotainment processor power supply

TIDA-00746 is a 17W system-optimized SMPS design for automotive infotainment processor power supply. This design has been tested and complies with CISPR25 Class 5 conducted EMI limits. All buck converters used in this design switch at frequencies above the AM band (>1.85MHz).

The design is divided into four main parts:

1. ● Front-end protection: Various protections have been implemented such as protection against positive and negative pulses (ISO7630 pulses 1, 2a, 3a/b) through TVS, reverse terminal protection through innovative smart diodes (LM74610) and battery disconnection with OVP Switch protection (PFET).
2. ● EMI filters: Common mode and differential filters suitable for conducted EMI suppression.
3. ● Low EMI front-end DC/DC converter: LM53635-Q1 is a switching synchronous 3.5A buck regulator, used as a front-end DC/DC converter in this design. This 2.1MHz device is optimized for automotive and has low EMI. In addition to the spread spectrum option, the device is available in the automotive-qualified Hotrod(TM) QFN wettable side package, which reduces parasitic inductance and resistance while increasing efficiency, minimizing switch node ringing and significantly reducing EMI.
4. ● Downstream POL buck converters (such as LM26420-Q1 (integrated dual buck), TPS57114-Q1 and TPS57112-Q1): All POL switches used in this design have switching frequencies above the AM band. For high frequency noise sensitive rails, ferrite bead filters are used.

characteristic

• ● Wide input voltage front-end power supply for 10W-17W automobiles
• ● Off-battery operation mode with battery reverse protection
• ● Series fault protection FET with OVP function on input
• ● Passed CISPR25 Category 5 conducted EMI test
• ● All devices are available in AEC-Q100 qualified versions
• ● Switching frequency: All converters used are above the AM band (>1.85MHz)