Power devices save board space, lower EMI, and speed the design process

By Jean-Jacques
DeLisle, contributing writer

A
buck converter, or a step-down converter, is a type of DC/DC power converter
that produces a lower voltage level at the output compared to the source input.
Typically, buck converters are designed using switched-mode power supplies,
comprised of several transistors/diodes, and passive components, such as
capacitors, inductors, and resistors. Buck converters are often used in place
of linear regulators, as they are typically far more power efficient and also
step-up output current, though buck converters are generally more complex and
potentially more expensive than some linear regulators.

 

These
devices are used in a wide array of electronics applications, spanning
virtually every electronics industry that requires multiple levels of DC
voltage for an application. These applications include computers, automobiles,
aircraft, hand-held electronics, smartphones, sensors, and Internet of Thing
(IoT) devices. Here is a sampling of the latest buck converters available in
the market.

 

 

GE’s new 60.8-square-millimeter (mm) Femto DLynx II buck
converters, the
FKX003 and FKX006
, offer the company’s smallest point-of-load (PoL) footprint
to date and are available in either 3-A or 6-A modules. These voltage
regulators use minimal board space compared to designs that place power
components directly on the main board and the IPC9592 qualification ensures
high reliability in all applications, said the company. The high-efficiency,
fully integrated PoL power modules convert 5-volt or 12-volt bus voltages to
lower voltages of 0.6 volt to 5.5 volts, as required by the load.

 

The FKX006 and FKX003 converters also
have wide input and output voltage ranges — 4.5 volts to 14.4 volts and 0.6
volt to 5.5 volts, respectively — and high efficiencies of up to 93.5 percent.
Both devices support patented Tunable Loop, which provides superior transient
performance while minimizing required output capacitors. The 6.76-mm x 9-mm
DLynx II PoL modules provide the same benefits as GE’s previous analog,
low-current DLynx 3-A and 6-A DC/DC, non-isolated converters, but in a 58 percent
smaller package (61 mm2 instead of 144 mm2) without compromising the reliability
and performance of the Lynx/TLynx/DLynx series, said the company.

 

The small footprint will be particularly appealing to
applications that are limited in board space or where low-risk design is
required, said GE. Applications range from portable industrial devices,
industrial automation and test and measurement to telecom and wireless
infrastructure equipment to servers/storage and routers and switchers.

 

The
FKX003 and FKX006 Femto DLynx II converters are available, with prices starting
at $3 and $6, respectively, in OEM quantities.

 

 

 

Maxim
Integrated touts the pin-compatible MAX20073 and MAX20074 PoL buck
converters can significantly lower electromagnetic interference (EMI) in
automotive applications thanks to its unique spread-spectrum and SYNC In
features that mitigate system EMI radiation. The MAX20073/MAX20074 claim the
lowest EMI in the industry for low-voltage PoL applications, reducing
interference that can impact the function of sub-systems.

 

Other
key features include high efficiency across the entire operating range and
ultra-low quiescent current. The devices are housed in a small 3 mm x 3 mm,
10-pin TDFN-EP package, which translates into a lower overall system footprint.

 

The
MAX20073/MAX20074 delivers up to 3-A load current from 0.5 V to 3.8 V. The
devices operate from an input voltage range of 2.7 V to 5.5 V, making them
suitable for on-board point-of-load and post-regulation applications. Total
output error is less than ±1.5% over load, line, and temperature. The devices
feature fixed-frequency PWM mode of operation with a 2.2-MHz switching
frequency and an all-ceramic capacitor design. The low-resistance on-chip
switches ensure high efficiency at heavy loads while minimizing critical
inductances, said Maxim.

 

The
output voltage accuracy makes these devices suited for applications that have
these tight processor and memory voltage requirements, particularly automotive
infotainment and ADAS applications, said Maxim.

 

The
ICs also adhere to tight safety standards, operate with low-input voltages
across a wide range of temperatures, and minimize radio frequency interference
while exhibiting high accuracy, high efficiency, and high reliability.

 

The
MAX20073 is priced at $1.20 and the MAX20074 is available for $1.30. The MAX20073EVKIT# and MAX20074EVKIT# evaluation kits
are priced at $45. Designers are recommended to contact Maxim for
pin-compatible ASIL variants. 

 

Texas Instruments launched two
wide-VIN synchronous SIMPLE SWITCHER DC/DC buck regulators
in
ultra-small HotRod quad flat no-lead (QFN) packaging. The highly integrated 3-A
LMR33630 and 2-A LMR33620 step-down voltage converters feature full load
efficiency at 92% with switching frequencies up to 2.1 MHz. When used in
conjunction with TI’s WEBENCH Power Designer, the converters can simplify power
conversion and speed the design process.

 

The
3.8-V to 36-V LMR33630 and LMR33620 buck
regulators
are offered in 3-mm x 2-mm thermally enhanced
packaging. The small HotRod QFN package includes unique wettable flanks
enabling post-solder optical inspection to simplify manufacturing and gives the
LMR33630 the industry’s highest 0.5A/mm2 power density at 3 A of current, said
TI. In addition, the “optimized package construction and symmetrical pin
placement minimizes parasitic inductance and facilitates optimal placement of
input bypass capacitors to mitigate conducted and radiated noise emissions,”
said the company.

 

Key
specs:

 

●  Operating input voltage ranges as high as 36 V
for nominal 12-V or 24-V systems such as factory and home automation, motor
drives, inverters and servo control units

●  Full load efficiency of 92 percent at 24 VIN, 5
VOUT and a 400-kHz switching frequency with a low 24-µA typical standby
quiescent current to increase light load efficiency

●  Devices
are also available in 8-pin, 5-mm x 6-mm SOIC packages

 

The 36-V LMR33630 and LMR33620 are priced in small
reels at $1.86 and $1.75, respectively, in quantities of
1,000-unit quantities. The 60-V LMR36015 and LMR36006 are priced in small
reels at $1.84 and $1.61, respectively, in quantities of 1,000.
All four devices are available in the 12-pin HotRod package. Available in
the 8-pin SOIC package, the 36-V LMR33630 and LMR33620 are priced in small
reels at $1.62 and $1.52, respectively, in quantities of 1,000. The EVMs can be ordered as follows:

 

LMR33630