Isolated 12-port PoE PSE controller chipset eliminates optos to reduce costs
May 02, 2011 // Paul Buckley
Linear Technology Corporation has introduced an isolated 12-port Power Source Equipment (PSE) controller chipset designed for use in IEEE 802.3at (PoE+) Type 1 and Type 2 compliant Power over Ethernet (PoE) systems. The LTC4270/71 provides 12 independent PSE channels for simpler, lower component count designs, reduced board space and lower solution costs.
The LTC4271 provides a digital interface to the PSE host, while the LTC4270 proffers the high voltage Ethernet interface; the two ICs are then bridged by inexpensive Ethernet transformers. The transformer-isolated communication protocol replaces up to six expensive opto-couplers and a complex isolated 3.3 V supply used in traditional designs, resulting in cost savings and a more robust and manufacturable design.
The LTC4270/LTC4271 is suitable for a wide variety of PSE applications, including next generation switches, routers, hubs and midspans. Users will appreciate the robustness provided by 80 V port pins and lowest-in-industry power dissipation, making thermal design significantly easier than designing with PSEs that integrate more fragile normally higher RDS(ON) MOSFETs. Powered Device (PD) discovery is accomplished using a proprietary dual-mode, four point detection mechanism that ensures the best immunity from false PD detection. Advanced power management includes prioritized fast shutdown, 14-bit per-port voltage and current readback, 8-bit programmable current limits and 7-bit programmable overload current limits and field-upgradeable firmware. A 1 MHz I2C interface allows a host controller to digitally configure the IC or query port readings. “C” libraries are available to reduce engineering costs and improve time to market.
The LTC4270 is available in three power grades: A-grade uses Linear's LTPoE++ signaling to support up to 90W PDs, B-Grade uses PoE+ signaling to support up to 25.5 W PDs, and C-grade uses PoE signaling to support up to 13W PDs. All chipsets are offered in industrial temperature grades. The LTC4270 is in a RoHS-compliant 52-pin 7 mm x 8 mm QFN package, while the LTC4271 is in a 24-pin 4 mm x 4 mm QFN package.
The LTC4270/71 chipset is priced starting at $12.00 each in 1,000 piece quantities and is now available in production quantities. The LTC4270/LTC4271 is backward compatible with the LTC4266 4-port PoE+ PSE controller and LTC4274 single-port PoE+ PSE controller, supported by Linear's extensive technical experience in PoE circuit design, ensuring a smooth transition to the new PoE+ standard or higher power levels.
More information about the LTC4270 chipset at www.linear.com/product/LTC4270.
Rohm's European Design Center in growth phase
November 21, 2014
At Electronica EE Times Europe caught up with Michael Davis European R&D director at the European Design Center (EDC) of ...
Combo inertial sensor market on 19% CAGR, says Yole.
US, China pushing industrial chip market growth, says IHS
LA Auto Show: Hydrogen fuel cell drive is back
Opening up the IoT data flood gates
Polarizing filter reduces energy drain from smartphone displays
November 21, 2014
A polarizing filter has been developed by University of Utah engineers which allows in more light, leading the way for mobile ...
From warm to cool white: colour-temperature tunable LEDs
System provides high-volume solution for flexible OLED displays
Isabellenhütte diversifies channels, clientele
- Halogen-free options and increased performance for terminal blocks
- Wireless Power User Guide
- Secure is the New Smart
- 5 Best Practices for Designing Flexible Test Stations
InterviewFreescale CEO: 'IoT isn't just buzz'
Coming after the solid third quarter results that produced higher operating margins and improving cash flow, Freescale Semiconductor's CEO Gregg Lowe had every reason to be chipper and lively when EE Times ...
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, Cherry is giving away five of its Energy Harvesting Evaluation kits, worth over 266 Euros each, for EETimes Europe's readers to win. Cherry's energy harvesting technology benefit mostly applications where a complex wire assembly and/or batteries would be inappropriate.
The required RF-energy is created by the mechanical actuation of the switch and the data is transmitted...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.
Most popular news
- Could magnesium battery innovation end lithium's dominance?
- From warm to cool white: colour-temperature tunable LEDs
- Li-Fi communication module wirelessly transfers data at 1-Gbps
- Supercapacitor innovation promises panel-powered cars in five years
- Rebranding the revolution: the future of IoT is embedded