Product category:
Power Supply ICs and Controllers
News Release from: Linear Technology Corp | Subject: LTC3557
Edited by the Electronicstalk Editorial
Team on 17 October 2007
Power management IC offers fast charging
The powerpath manager in the LTC3557 seamlessly manages the transition between multiple input sources and power to the load
Linear Technology has released the LTC3557, a multi-function power management solution for Li-Ion/Polymer battery applications The LTC3557 integrates a linear PowerPath manager, a stand-alone battery charger, an ideal diode, three high-efficiency synchronous buck regulators and an always-on LDO in a low-profile 4 x 4mm QFN package
This article was originally published on Electronicstalk on 28 Jul 2004 at 8.00am (UK)
Related stories
Card power chip meets smart and SIM standards
The LTC4557 is a dual SIM/smart-card power supply and level translator, which provides both 1.8 and 3V SIM power and digital signal level shifting from a 3 x 3mm QFN package.
RF mixers take transformers onboard
Linear Technology has released two new high linearity up-converting RF active mixers with integrated RF transformers.
The powerpath manager seamlessly manages the transition between multiple input sources and power to the load, while for fast charging the linear battery charger delivers up to 1.5A charge current from a wall adapter supply or up to 500mA charge current from a USB port.
The LTC3557's three integrated synchronous buck regulators feature 100% duty cycle operation and are capable of delivering output currents of 600/400/400mA respectively, with adjustable output voltages down to 0.8V.
The 2.25MHz switching frequency allows the use of tiny low cost capacitors and inductors less than 1mm in height.
The internal low RDS(ON) switches enable efficiencies as high as 95%, maximising battery run time.
In addition, pin-selectable burst mode operation optimises efficiency at light loads with a quiescent current of only 35uA per regulator (less than 1uA in shutdown).
Furthermore, the regulators are stable with ceramic output capacitors, achieving very low output voltage ripple.
The LTC3557's stand-alone autonomous operation simplifies design, eliminating the need for an external microprocessor for charge termination.
To preserve battery energy, the IC draws less than 6uA from the battery in suspend mode.
The LTC3557 can control a high-voltage buck regulator to achieve high efficiency bat-track charging and powerpath control from a high voltage source, reducing power dissipation.
The charger is compatible with inputs up to 5.5V (7V absolute maximum transient for added robustness).
The internal 200mohm ideal diode plus optional external ideal diode controller provide a low-loss power path when input current is limited or unavailable, maximising thermal performance.
The LTC3557 is available from stock in a 4 x 4 x 0.75mm QFN-28 package. Request a free brochure from Linear Technology Corp ...
• Linear Technology Corp: contact details and other news
• Email this article to a colleague
• Register for the free Electronicstalk email newsletter
• Electronicstalk Home Page
Search the Pro-Talk network of sites
