Description

TIDA-00746 is a 17W system-optimized SMPS design for automotive infotainment processor power. The design has been tested for and passed CISPR25 Class 5 conducted EMI  limits.  All buck converters used in this design is switching above AM band (>1.85MHz).The design is divided into four major blocks:Front end protection:  Various protections have been implemented: such as those against positive and negative pulses (ISO7630 Pulse 1: 2a: 3a/b) through TVS: reverse terminal protection through innovative smart diode (LM74610): and battery disconnect switch with OVP protection (PFET).EMI filter: a common mode and a differential filter for conducted EMI suppression.Low EMI front end DC/DC converter: LM53635-Q1 is a switching: synchronous 3.5A buck regulator and is used as a front end DC/DC converter in this design. This 2.1 MHz part is automotive optimized and has low EMI. Apart from the spread spectrum option: the device comes in an automotive-qualified Hotrod(TM) QFN package with wettable flanks: which reduces parasitic inductance and resistance while increasing efficiency: minimizing switch node ringing: and dramatically lowering EMI.Downstream POL buck converters such as: LM26420-Q1 (Integrated dual buck): TPS57114-Q1: and TPS57112-Q1: all POL switchers used in the design switch above AM band. For high frequency noise-sensitive rails: a ferrite bead filter is used.