Design Con 2015
Breaking News
Newest First | Oldest First | Threaded View
User Rank
re: Multiphase boost converter eases 12V battery 'cranking deep'
GREAT-Terry   6/15/2011 3:36:56 PM
If everything stays at 12V, just a boost is not good enough as there is also a load dump situation when the input voltage can fly up as high as 100V (with TVS clamp it can also be around 40-60V) so a 12V system indeed is not a 12V system. So I don't think a boost converter boosting the input o 12V or 24V (for audio as mentioned in the article) helps. Fortunately, most electronics run at much lower voltage (3.3V, 5V etc.) so there is a high voltage buck after the so-called 12V rail. However, if a real robust 12V is needed, people have to consider the buck-boost or SEPIC design.

User Rank
re: Multiphase boost converter eases 12V battery 'cranking deep'
MAUP   5/4/2011 6:11:11 PM
A simpler solution is to run critical functions off a supply voltage lower than any possible dip in battery voltage, and use buck converters for POL voltage regulators

Don J
User Rank
re: Multiphase boost converter eases 12V battery 'cranking deep'
Don J   5/4/2011 1:30:40 PM
Geoff, Not sure what you mean by "main battery". I believe this article is addressing simple, stop-start only, micro-hybrid vehicles (not mild or full hybrid vehicles which have a secondary high voltage battery). These micro-hybrid vehicles typically use a single 12V lead-acid battery, often an AGM for better cycle life. They are prone to voltage sag during starting since the starter (either an enhanced cranking motor or a Belted-Alternator-Starter or an Integrated Starter Generator) rely on the 12V battery for cranking energy. Mild or full hybrids with a secondary high voltage battery all use the high voltage battery for re-starting and therefore do not have the voltage sag problem during re-starts. Certainly a bigger battery would help, but it is a trade-off between a bigger battery and a DC-DC boost converter. The bigger battery will still have voltage sag during cranking which may be noticed by the customer in the form of dimming lights, slower blower speeds, etc. The big difference here is that during a normal start the electrical accessories are (intentionally) turned off. During stop-start the accessories are still active and one of the goals is to make the stop-start function as transparent to the customer as possible. Don

Geoff Thomas
User Rank
re: Multiphase boost converter eases 12V battery 'cranking deep'
Geoff Thomas   5/4/2011 8:17:17 AM
Hey guys, this is nothing new, - just use a bigger battery, or even better, use the cars' main battery, - no way it is going to be dragged down by deep cranking, far too big.

Top Comments of the Week
Flash Poll
Like Us on Facebook Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Max Maxfield

Feast Your Orbs on My Vetinari Clock Prototype
Max Maxfield
Well, I have to admit that I have a great big Cheshire Cat-type grin plastered on my face at the moment, because the prototype for my Vetinari Clock project is now well underway.

Jack Ganssle,

Open Office: Your Fart is My Problem
Jack Ganssle,
A Washington Post article, Google got it wrong. The open-office trend is destroying the workplace, describes how the author's ad agency moved her from a private office to an open space ...

Rich Quinnell

Bloopers Book Helps Improve GUI Development
Rich Quinnell
Courtesy of fellow editor "Max" Maxfield (aka Max the Magnificent), I recently acquired a copy of GUI Bloopers 2.0 by Jeff Johnson of UI Wizards. I found it an interesting read chock full ...

Rich Quinnell

Making the Grade in Industrial Design
Rich Quinnell
As every developer knows, there are the paper specifications for a product design, and then there are the real requirements. The paper specs are dry, bland, and rigidly numeric, making ...

Special Video Section
The LT8640 is a 42V, 5A synchronous step-down regulator ...
The LTC2000 high-speed DAC has low noise and excellent ...
How do you protect the load and ensure output continues to ...
General-purpose DACs have applications in instrumentation, ...
Linear Technology demonstrates its latest measurement ...
Demos from Maxim Integrated at Electronica 2014 show ...
Bosch CEO Stefan Finkbeiner shows off latest combo and ...
STMicroelectronics demoed this simple gesture control ...
Keysight shows you what signals lurk in real-time at 510MHz ...
TE Connectivity's clear-plastic, full-size model car shows ...
Why culture makes Linear Tech a winner.
Recently formed Architects of Modern Power consortium ...
Specially modified Corvette C7 Stingray responds to ex Indy ...
Avago’s ACPL-K30T is the first solid-state driver qualified ...
NXP launches its line of multi-gate, multifunction, ...
Doug Bailey, VP of marketing at Power Integrations, gives a ...
See how to ease software bring-up with DesignWare IP ...
DesignWare IP Prototyping Kits enable fast software ...
This video explores the LT3086, a new member of our LDO+ ...
In today’s modern electronic systems, the need for power ...