Products in Focus | Power Supplies
Abroad range of systems continue
to employ increasing numbers
of advanced SoC (System on
Chip), FPGA, and microprocessor
solutions. Each successive generation
expands in power budget as powerhungry
components are added and
data processing speeds rise to support
live streams of telecom, audio, or video
data.
These demands can only be met
by robust, easy to use low voltage
power supplies with high efficiency,
high power density, and low
electromagnetic radiation.
SoCs and FPGAs require a number
of low voltage supplies, including 1.1V
for DDR, 0.8V for core, and 3.3V/1.8
V for I/O devices. Delivering sub-1V
will usually require two stages: an
intermediate regulation stage to 12
V or 5 V, and another to low voltage.
Each dc-to-dc conversion must be
efficient and pass EMI standards to
enable the overall power system to
perform efficiently.
It can be difficult to meet size,
efficiency, and EMI design goals
using conventional buck regulators.
Sub-1 V buck regulators traditionally
rely on bulky and EMI noisy PWM
controllers and MOSFETs. The
demands of automotive and industrial
systems mean that devices must give
way to something more compact,
with higher current capability,
higher efficiency, and superior EMI
performance.
Monolithic Silent Switcher 2 buck
regulators in the LTC7150S and
LT8642S family have been designed to
address these SoC power demands.
EMI performance
EMI issues that crop up in the late
phase of the design and development
of a system can cost significant
money and time in troubleshooting
and redesign. So, to assure EMI
qualification throughout the
power supply design process, EMI
suppression is often prioritised, and
sometimes over-engineered, at the
expense of other desirable features
- namely efficiency, reliability, and
simplicity.
EMI usually involves slowing
down switching edges and/or lowering
switching frequency. However, this
can come with significant trade-offs,
including increased minimum ontimes,
limited voltage conversion
ratios, and larger solution size.
Alternative mitigation techniques, such
as bulky EMI filters or metal shielding,
add significant costs in board space,
an increased component count, and
greater assembly complexity.
None of these strategies meet the
requirements of the demanding SoC
power budgets of compact size, high
efficiency, and low EMI.
6 www.newelectronics.co.uk
www.digikey.co.uk
Image: kran77/stock.adobe.com
Powering advanced components
High efficiency monolithic regulators are being used to power advanced
SoCs and microprocessors. By Ying Cheng and Zhongming Ye
/www.newelectronics.co.uk
/www.digikey.co.uk
/stock.adobe.com