Linear's Failsafe and Charging ICs

Date
10/27/2010

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New uModule Battery Chargers with Active Current Limit Deliver 2A from up to 32VIN

Compact Triple Supply Monitoring with Power-Fail Detection

Precision Triple Supply Supervisor Provides Early Power-Fail Detection Linear Technology Corporation introduces the LTC2911 three-channel supply monitor with power-fail warning for low voltage systems down to 0.5V. In certain applications, monitoring the main input supply is just as important as monitoring the intermediate bus voltages in order to provide the host an early warning of supply failure and signal shutdown procedures. The LTC2911 offers a power-fail input and output to support this function, in addition to three voltage inputs, with 1.5% threshold accuracy over the entire operating temperature range. The LTC2911 is suitable for a wide variety of applications, including network servers, desktop or notebook computers, and automotive or industrial electronics. The first channel monitors 3.3V, the second channel monitors pre-set values between 1.2V to 5V and the third channel is adjustable down to 0.5V. This versatility allows the LTC2911 to be conveniently ported to similar designs with differing supply voltages. Glitch filtering ensures reliable reset operation by minimizing false triggers. The reset timeout period can be selected internally (200ms) to minimize component count, or externally adjusted. The same reset timer pin can also be used to latch the reset pin status and override reset operation, which is useful in margining applications, where it is common to test systems at supply voltages that might otherwise cause the system to reset. The LTC2911 is available in a variety of voltage options, depending on which three voltages need to be monitored. Commercial and industrial versions offer different operating temperature ranges, from 0°C to 70°C and -40°C to 85°C, respectively. The LTC2911 is available today and offered in 8-lead TSOT-23 and 3mm x 2mm DFN packages. Please visit www.linear.com/2911 for more product selection and information. Summary of Features: LTC2911 • Ultralow Voltage Reset: VCC = 0.5V Guaranteed • Monitors Three Inputs Simultaneously: • Ī1.5% Threshold Accuracy • Power-Fail Monitor • Reset Status Can Be Latched for Margining • Low Supply Current: 30uA Typical • Input Glitch Immunity • Adjustable Reset Timeout Period • Selectable Internal Timeout Saves Components • Open-Drain /RST, /PFO Outputs • Space Saving 8-Lead TSOT-23 & 3mm x 2mm DFN Packages

Linear Technology announces the immediate availability of the LTM8061 and LTM8062, the first devices in a new family of complete system-in-a-package uModule® chargers, supporting an output charge current up to 2A. Both parts provide a complete, efficient 1MHz switching step-down charger solution with as few as just one input capacitor. The LTM8061 features active input-current management to protect against supply rail droop, while providing maximum charge current to the load. The LTM8062 actively manages the output charge current to maximize the power sourced from a solar cell following Maximum Peak Power Tracking (MPPT) principles. The LTM8061 and LTM8062 operate from an input voltage range of 4.95V to 32V with support for preconditioning, constant-current and constant-voltage mode operation. A 0.5% and 0.75% accurate float voltage respectively ensures maximum energy storage at charge termination set by a minimum current threshold detection or adjustable internal timeout. The LTM8061 is specifically targeted for charging Li-Ion or Li-polymer batteries with float voltages of 4.1V, 4.2V, 8.2V and 8.4V. An externally adjustable float voltage allows the LTM8062 to support charging of single-and multi-cell Li-Ion, Li-polymer, Lithium iron phosphate (LiFePO4) and sealed lead acid (SLA) batteries up to 14.4V. To maintain the battery at full charge, the LTM8061 and LTM8062 automatically initiate a recharge cycle once the battery voltage drops to 2.5% below the float voltage. Safety features include bad-battery detection and NTC resistor input with fault indicator suitable for use with a LED. An internal input reverse voltage blocking diode is available to prevent leakage current from the battery when the power source is not present. For more information,visit www.linear.com/8061 and www.linear.com/8062. Summary of Features: LTM8061 & LTM8062 • Complete 1MHz System-in-a-Package Step-Down Battery Chargers in 9mm x 15mm x 4.32mm LGA Package • 4.95V to 32VDC (40V Abs Max) Operating Input Voltage Range • Adjustable Charge Current up to 2A (LTM8061) • Precondition, Constant-Current, Constant-Voltage Charging • Internal Minimum Current or Time-Out Charge Termination • Fixed 4.1V, 4.2V, 8.2V, 8.4V Battery Float Voltage (LTM8061) • Adjustable Battery Float Voltage up to 14.4V (LTM8062) www.linear.com

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