XD9707/XD9708 Series of AEC-Q100 Grade 1 (-40 °C to 125 °C) Compliant, 36 V Withstand Voltage Synchronous Step-down DC/DC Converters, Among the Smallest in the World

Torex Semiconductor Ltd. (Tokyo Japan: President, Koji Shibamiya, 6616: 1st section at Tokyo Stock Exchange) has launched the XD9707/XD9708 Series of AEC-Q100 Grade1 (using temperature range: from -40 °C to 125 °C) Compliant, 600mA synchronous step-down DC/DC converters with an internal 36 V operation driver transistor.

The required voltage for conventional automobile body-related applications is commonly 5V, and when supplying 5V directly from 12V in-vehicle batteries, it has been general practice to use large-package regulators equipped with heat sinks.However, the conversion to low voltages such as 3.3V even for body-related applications is progressing, and in consideration for the dropout voltage compared to 12V in-vehicle batteries as well as the load current, there are now concerns emerging overheat dissipation with the use of conventional regulators.

The XD9707/XD9708 series consists of ultra-compact DC/DC converters developed with the intention to replace such applications where regulators were used as power supply ICs with voltage directly supplied from 12V in-vehicle batteries.These components have an input voltage range of 3.0V to 36.0V (absolute maximum rating of 40V), an output voltage range of 1.8V to 12.0V, and a switching frequency of 2.2MHz. Their operating modes can be selected from PWM control (XD9707) or PWM/PFM automatic switching control (XD9708), and they can achieve high efficiency and low ripple voltage in all load regions from light to heavy loads. Their packages can be selected to suit the application from either the SOT-89-5, or the compact USP-6C (1.8 x 2.0 x h0.6 mm), which is one of the world’s smallest 600 mA class packages with 36V withstand voltage.

With an extremely high light load (1 mA) efficiency of 74 %, they have half the power consumption and half the mounting area of components that supply voltage directly through regulators from 12 V in-vehicle batteries, for significant reductions in both power and size (Figure 1).Their soft-start time is internally set to be 2.0 ms (Typ.), and longer times can be set as desired according to resistance and capacity. They are internally equipped with over current limit, UVLO, and thermal shutdown as protective functions.Furthermore, they are also compatible with an operating temperature range up to 125 °C, a specification whose demand is rising due to increases in output current, allowing them to be used without concern.

Fig1. Package USP-6C（1.8 x 2.0 x 0.6mm）