Automotive AEC-Q100 Grade 1 Compliant High-Voltage 36V/600mA Compact Step-Down DC/DC Converter

­Torex Semiconductor Ltd. has launched the XD9704/XD9705 series, a new series of step-down DC/DC converters compliant with the automotive standard AEC-Q100 Grade 1.

The XD9704/XD9705 series is a low-power, synchronous step-down DC/DC converter that achieves space savings while supporting a high withstand voltage of 36V. The input voltage supports up to 36V, with a peak voltage of 46V (≤400ms), making the series suitable for +B inputs in automotive applications. It also provides a maximum output current of 600mA, sufficient for applications such as communication systems and sensors. In addition, the operating temperature range complies with AEC-Q100 Grade 1, from -40°C to +125°C.

The switching frequency is set at 2.2MHz, which is suitable for use in automotive applications. Since small external components, including inductors and capacitors, can be used, the required mounting area is as small as 48.7mm², contributing to space savings. Furthermore, with a low quiescent current of only 11μA, the series achieves an efficiency of 90% under VIN=12V, VOUT=5V, and IOUT=1mA, delivering high efficiency from light loads to heavy loads. By taking advantage of these space-saving and high-efficiency features, the heat generation issues of conventional medium- to high-voltage LDOs with relatively large package sizes can be easily resolved by replacing them with the XD9704/XD9705 series.

In addition, unlike the N-channel driver FET commonly used in medium- to high-voltage DC/DC converters, the XD9704/XD9705 series integrates a P-channel driver FET, enabling 100% duty-cycle operation. Even when the input voltage drops below the output voltage setting, such as during engine cranking, the input voltage can be passed directly through to the output. This enables reliable operation even under conditions where the difference between the input and output voltages is small. Furthermore, the Power Good function, which indicates that the output voltage has risen sufficiently, and the soft-start function at startup enable power sequencing control of downstream load systems.

The XD9704 series adopts fixed F-PWM control, which enables stable operation with consistently low ripple voltage, while the XD9705 series adopts automatic PWM/PFM switching control to maintain high efficiency from light loads to heavy loads. Users can select the optimal control method according to their application requirements. Two package options are available: the easy-to-mount SOT-89-5 (4.5 x 4.6 x 1.6mm) and the compact, low-profile DFN1820-6J (1.8 x 2.0 x 0.6mm; under development), featuring a wettable flank structure that allows visual inspection of the solder fillets.

With greater design flexibility, the XD9704/XD9705 series is a compact, general-purpose, high-voltage product designed for high-reliability applications, particularly automotive equipment for sensors and communications, as well as industrial equipment where miniaturization is strongly required.

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