AST1S31PUR STMicroelectronics

AST1S31 Up to 4 V, 3 A step-down 1.5 MHz switching regulator for automotive applications Datasheet - production data Applications Designed for automotive systems Battery powered applications Car body applications Description The AST1S31 device is an internally Features compensated 1.5 MHz fixed-frequency PWM synchronous step-down regulator. The AST1S31 AECQ100 qualification device operates from 2.8 V to 4 V input, while it 3 A DC output current regulates an output voltage as low as 0.8 V and up to V . IN 2.8 V to 4 V input voltage The AST1S31 integrates a 70 m high-side Output voltage adjustable from 0.8 V switch and a 55 m synchronous rectifier 1.5 MHz switching frequency allowing very high efficiency with very low output Internal soft-start and enable voltages. Integrated 70 m and 55 m power MOSFETs The peak current mode control with an internal All ceramic capacitor compensation deliver a very compact solution with a minimum component count. Power Good (POR) The AST1S31 device is available in a 3 x 3 mm, 8 Cycle-by-cycle current limiting leads VFDFPN package. Current foldback short-circuit protection VFDFPN 3 x 3 - 8L package Figure 1. Application circuit / 1 92 87 6 9, : 1 6: 9, 1 5 67 6 &LQBD (1 &RX W 3* Z QBV & L 5 August 2020 DocID025467 Rev 7 1/35 This is information on a product in full production. www.st.com *1 9)% 9,Contents AST1S31 Contents 1 Pin settings 4 1.1 Pin connection 4 1.2 Pin description 4 2 Maximum ratings 5 2.1 Thermal data . 5 2.2 ESD performance 5 3 Electrical characteristics . 6 4 Functional description . 8 4.1 Output voltage adjustment . 9 4.2 Soft-start 10 4.3 Error amplifier and control loop stability 10 4.4 Overcurrent protection . 15 4.5 Enable function 17 4.6 Light load operation . 18 4.7 Hysteretic thermal shutdown 18 5 Application information . 19 5.1 Input capacitor selection 19 5.2 Inductor selection . 20 5.3 Output capacitor selection 21 5.4 Thermal dissipation . 22 5.5 Layout consideration 23 6 Demonstration board . 25 7 Typical characteristics 27 8 Package information 31 8.1 VFDFPN8 (3 x 3 x 1.0 mm) package information . 31 2/35 DocID025467 Rev 7