Current-sharing, diode-OR controller simplifies power system design
June 05, 2012 // Paul Buckley
Claiming a first-of-its-kind current-sharing controller with reverse current blocking, the LTC4370 from Linear Technology frees the designer from the limitations and complications of existing current-sharing methods to obtain a simpler, quicker, and space-saving solution for sharing between two supplies.
The device’s supply-agnostic feature lends the design more flexibility and a longer lifetime. By incorporating diode behavior, the controller prevents one supply failure from bringing down the entire system.
Designers of high availability systems frequently engineer redundancy into their power systems by paralleling two similar supplies with diodes (diode-OR) such that one can handle the load when the other fails. System reliability is further increased if both supplies operate simultaneously, each sharing half the load current. Lower currents lead to cooler operation, reducing the failure rate by half for every 10°C fall in temperature. Other load-sharing benefits include faster recovery after supply failure, and the ability to operate supplies near their peak efficiency point. Prior to the LTC4370, load-sharing solutions demanded active control of the supplies through their trim pins or feedback networks. They also required a share bus, and stability compensation dependent on the supply type. The LTC4370 simplifies designs of reliable power systems.
The LTC4370 controls N-channel MOSFETs in series with each supply. These MOSFETs act like diodes with a variable forward voltage. The LTC4370 adjusts the forward voltage of the MOSFET diodes to offset the mismatch in input supply voltages until the currents from each supply are equal. To limit MOSFET power dissipation, the maximum voltage drop across the MOSFET is adjustable with an external resistor. The controller operates with supplies in the range of 0 V to 18 V. During faults, a fast MOSFET turn-on and turn-off limits the load voltage droop and shoot-through currents between supplies. Enable pins can turn each MOSFET off; when both are off, the controller bias current is lowered. Status pins indicate the MOSFET on state, which can be used to signal a break in current sharing by lighting a red LED. The load sharing feature can also be switched off to turn the device into a dual ideal-diode controller.
Availability and Pricing
Specified over the full commercial and industrial temperature ranges, the LTC4370 is offered in 16-pin DFN (4mm x 3mm) and MSOP packages. Pricing begins at $4.95 each for 1,000-piece quantities and the device is available today in production quantities. Evaluation circuit boards are available online or from your local sales office.
More information LTC4370 current-sharing controller at
Structural electronics - the next big thing in smart cars?
September 18, 2014
Electronic circuits embedded in vehicles, aircraft and more have the potential to be a $60 billion market by 2025, says technology ...
Elastomeric camouflage switches texture and colour
Solar microinverter to break USD1bn barrier in 2018
7nm EUV could ease 10nm squeeze, says ASML
Europeans flex skills to commercialize OLED and OPV devices
Freescale opens Discovery Lab in Toulouse to foster innovation
September 17, 2014
Shortly after the company celebrated the first year of existence of its Austin-based Freescale Discovery Lab, an incubator ...
Can a large-area flexible OLED have reliable contacts?
Lemoptix pico-projector excels
Building ARM-based Bluetooth-enabled wearables
- Putting FPGAs to Work in Software Radio Systems Handbook
- Flexible and Low Power Driving of Solenoid Coils
- How to Protect & Monetize Android Apps
- Power Modules: The New Super Power
InterviewCEO interview: AMS' Laney on driving a sensor-driven business
Kirk Laney, CEO of Austrian mixed-signal chip and sensor company AMS, wants to leverage the opportunity that technology affords to create new markets for sensors and sensor interfaces.
Filter WizardCheck out the Filter Wizard Series of articles by Filter Guru Kendall Castor-Perry which provide invaluable practical Analog Design guidelines.
Linear video channel
READER OFFERRead more
This month, Trinamic Motion Control is offering you to win one of four TMCM-1043 development kits for its highly integrated, NEMA 17-compatible TMCM-1043 stepDancer stepper motor module.
Offering designers an easy-to-use PC-based GUI that allows one-click modification of motor drive current, micro-stepping and other key parameters, the intuitive kits are custom designed and developed for...MORE INFO AND LAST MONTH' WINNERS...
December 15, 2011 | Texas instruments | 222901974
Unique Ser/Des technology supports encrypted video and audio content with full duplex bi-directional control channel over a single wire interface.