Maxim Unveils Dual, 3/5A, Step-Down Regulators
Maxim Integrated Products introduced the MAX8833/MAX8855 – described as the industry’s first step-down regulators to operate from 3.3 or 2.5V inputs, provide dual 3 or dual 5A outputs (respectively), and integrate switches that maximize space savings. The use of internal MOSFETs enables these devices to operate efficiently from low input voltages, which the company says is not possible with large, discrete MOSFETs.
Internal MOSFETs are claimed to provide much better performance in low-voltage applications compared to their discrete counterparts, which require higher voltages for full enhancement. With low on-resistances of 49 and 37mΩ, respectively, the MAX8833/MAX8855 are capable of providing efficiencies in the mid-90% range while switching above 1MHz. The low on-resistance, high efficiency, and small package of these devices make them suitable for DDR power supplies, processors that require more than one rail, and high-end enterprise equipment.
To increase design flexibility, each device provides a programmable frequency up to 2MHz and an external frequency-synchronization input. An external reference input enables the implementation of tracking applications, such as DDR power supplies, by allowing one channel to power Vddq while the tracking channel powers Vtt. Programmable soft-start for each channel supports a wide range of outputs, further enhancing flexibility. Additionally, a separate power-good signal and enable input for each output ensure simple sequencing. The MAX8833/MAX8855 also combine a high-bandwidth, voltage-error amplifier with high-frequency switching to allow the use of ceramic capacitors that have minimal values.
The MAX8833/MAX8855 are fully specified over the -40 to +85°C extended temperature range. Each device is available in a 5 x 5mm, 32-pin TQFN package to allow interchangeability as current requirements change.
Pricing starts at $2.59 for the MAX8833 and $3.41 for the MAX8855 (10,000-up, FOB USA).
