- TIDA-00746 Test Results
(PDF 1544 KB)
30 Nov 2016 2,057 views
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.
- Wide-Vin front end power supply for 10W-17W automotive
- Off-battery operation with reverse battery protection
- Series fault protection FET with OVP at input
- Passed CISPR25 Class 5 conducted EMI test
- All devices have an AEC-Q100 qualified version available
- Switching frequency: above AM band (>1.85 MHz) for all the converters used