Analog Devices – Automotive-grade step-down regulators reduce footprint and EMI

Analog Devices has released their Power by Linear ADP5138, automotive qualified, high efficiency, 3.2MHz synchronous quad output buck regulators, which incorporates a unique fixed frequency, peak current mode, PWM control architecture that reduces conducted and radiated emissions. The device’s high-efficiency buck regulators enhance thermal management, operate down to 0.8V outputs and deliver up to 1A of continuous output current from each channel. They also integrate a 250mA low output noise (20µVRMS from 10Hz to 100kHz), high PSRR (61dB at 1kHz) LDO for powering noise-sensitive devices. The high level of integration and blend of features, as well as the compact 4mm x 4mm LFCSP package, make it perfect for automotive, industrial and instrumentation systems, as well as DC-DC point-of-load applications where space is restricted. The device runs at a fixed PWM switching frequency of 3.2MHz or can be synchronized to the external clock from 2.8MHz to 3.5MHz, which is outside the AM band. Moreover, this high switching frequency lessens the size of external components, allowing a smaller solution footprint. The four buck regulators run 90-degrees out-of-phase to each other, lessening the input ripple current and the input capacitor size and lowering the system’s EMI. Additional protection includes OCP and TSD. The device and the automotive-qualified version, the ADP5138W, are provided in a low profile (0.75mm), compact 28-lead 4mm x 4mm LFCSP package with backside exposed metal pad for excellent thermal performance. The devices operate from –40C to 125C (junction temperature).