Diodes Inc. has expanded its synchronous buck converter portfolio with two new devices for a wide range of point-of-load (PoL) applications. The AP62500 and AP62800 with continuous output current ratings of 5 A and 8 A, respectively, enable engineers to optimize their PoL solutions for either efficiency or size. These buck converters also minimize electromagnetic interference (EMI) issues with a proprietary gate-driver design.
(Source: Diodes Inc.)
Aimed at delivering compact implementations with a minimal component count, the devices target mass-market consumer products, said Diodes. Applications include 5-V and 12-V distributed power bus supplies; television sets and monitors; white goods and small home appliances; FPGA, DSP, and ASIC supplies; home audio, network systems, gaming consoles, consumer electronics and general-purpose PoLs.
The buck converters offer wide input voltage ranges. The AP62500 covers 4.5 V to 18 V, while the AP62800 ranges from 4.5 V to 17 V, making both suitable for 5-V and 12-V rail applications. The output voltages can be adjusted down to 0.6 V. They offer designers three different switching frequencies – 400 kHz, 800 kHz and 1.2 MHz, allowing them to prioritize either higher conversion efficiency or a smaller form factor.
Other features include three selectable operating modes; pulse frequency modulation (PFM) for improved light-load efficiency, pulse width modulation (PWM) for reduced output voltage ripple and ultrasonic (USM) to avoid audible frequency range and to ensure the switching frequency stays above 20 kHz.
Diodes said the on-resistance (RDS(ON)) figures are kept low in relation to both the high-side MOSFET (47 mΩ for AP62500 and 22 mΩ for AP62800) and low-side MOSFET (18 mΩ for AP62500 and 10 mΩ for AP62800), which helps to improve step-down conversion efficiency levels. In addition, an ultra-low quiescent current (IQ) is achieved while in PFM mode (195 μA typical), enhancing light-load efficiencies, said the company, and soft-start-time adjustability protects against the risk of damage from inrush currents.
Thanks to a proprietary gate-driver design, the buck converters mitigate switching-node ringing without having to extend MOSFET turn-on/turn-off times, said Diodes, which would impact high-frequency switching capabilities. The buck converters also feature constant on-time (COT) control, which provides fast transient response and low-output voltage ripple and better loop stabilization.
Pricing for the AP62500 and AP62800 is $0.325 and $0.570, respectively, in quantities of 1,000. They are both supplied in 12-pin V-QFN2030 packages.
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