A6984 36 V, 400 mA automotive synchronous step-down switching regulator Datasheet - production data Applications Car body and ADAS applications (LCM) Car audio and low noise applications (LNM) VFDFPN10 4 x 4 x 1.0 mm Description The A6984 is a step-down monolithic switching regulator able to deliver up to 400 mA DC. The Features output voltage adjustability ranges from 0.9 V. The fixed 3.3 V VOUT requires no external resistor AEC-Q100 qualified divider. The low consumption mode (LCM) is 400 mA DC output current designed for applications active during car 4.5 V to 36 V operating input voltage parking, so it maximizes the efficiency at light load with controlled output voltage ripple. The low Synchronous rectification noise mode (LNM) makes the switching Low consumption mode or low noise mode frequency almost constant over the load current 75 A I at light load (LCM V = 3.3 V) range, serving low noise application Q OUT specifications such as car audio/sensors. The 13 A I Q-SHTDWN PGOOD open collector output can implement Adjustable f (250 kHz - 600 kHz) SW output voltage sequencing during the power-up Output voltage adjustable from 0.9 V phase. The synchronous rectification, designed for high efficiency at medium-heavy load, and the No resistor divider required for 3.3 V V OUT high switching frequency capability make the size V maximizes efficiency at light load BIAS of the application compact. Pulse-by-pulse 350 mA valley current limit current sensing on the low-side power element implements effective constant current protection. Constant on-time control scheme The package lead finishing guarantees side PGOOD open collector solderability, thus allowing visual inspection Thermal shutdown during manufacturing. Figure 1. Application schematic 8 / A6984 73 73 73 73 3*22 3*22 9,19,1 9,1 3*22 5 5 5 5 0HJ 0HJ 9%, 6 N N / / X+ X+ 73 73 1 92879287 / 73 73 5 5 0 0 (1(1 (1 9&& /10 )% (3 *1 & & Q) Q) 73 73 *1 *1 0 9 August 2020 DocID030396 Rev 4 1/49 This is information on a product in full production. www.st.com & & X) X) 9 9 & & Q) Q) 9 9 & & X X 72Contents A6984 Contents 1 Pin settings 4 1.1 Pin connection 4 1.2 Pin description 4 1.3 Maximum ratings 5 1.4 Thermal data . 5 1.5 ESD protection 6 2 Electrical characteristics . 7 3 Datasheet parameters over the temperature range . 10 4 Device description . 11 4.1 Output voltage adjustment 13 4.1.1 Maximum output voltage 13 4.1.2 Leading network 14 4.2 Control loop . 16 4.3 Optional virtual ESR network 20 Output voltage accuracy and optimized resistor divider . 24 4.4 Soft-start 28 4.5 Light load operation . 28 4.5.1 Low noise mode (LNM) . 29 4.5.2 Low consumption mode (LCM) . 29 4.6 Switchover feature 32 4.6.1 LCM 32 4.6.2 LNM 32 4.7 Overcurrent protection . 32 4.8 PGOOD 34 4.9 Overvoltage protection . 34 4.10 Thermal shutdown 35 5 Design of the power components . 36 5.1 Input capacitor selection 36 5.2 Inductor selection . 37 2/49 DocID030396 Rev 4