Analog Devices Inc./Maxim Integrated

The LTC1759 Smart Battery Charger is a single chip charging solution that dramatically simplifies construction of an SBS compliant system. The LTC1759 implements a Level 2 charger function whereby the charger can be programmed by the battery or by the host. A thermistor on the battery being charged is monitored for temperature, connectivity and battery type information. The SMBus interface remains alive when the AC power adapter is removed and responds to all SMBus activity directed to it, including thermistor status (via the ChargerStatus command). The charger also provides an interrupt to the host whenever a status change is detected (e.g., battery removal, AC adapter connection).Charging current and voltage are restricted to chemistry specific limits for improved system safety and reliability. Limits are programmable by two external resistors. Additionally, the maximum average current from the AC adapter is programmable to avoid overloading the adapter when simultaneously supplying load current and charging current. When supplying system load current, charging current is automatically reduced to prevent adapter overload.ApplicationsPortable ComputersPortable InstrumentsDocking Stations

The LTC1760 Smart Battery System Manager is a highly-integrated SMBus Level 3 battery charger and selector intended for products using dual smart batteries. Three SMBus interfaces allow the LTC1760 to servo to the internal voltage and currents measured by the batteries while allowing an SMBus Host device to monitor either battery’s status. Charging accuracy is determined by the battery’s internal voltage and current measurements, typically better than ±0.2%.A proprietary PowerPath architecture supports simultaneous charging or discharging of both batteries. Typical battery run times are extended by up to 10%, while charging times are reduced by up to 50%. The LTC1760 automatically switches between power sources in less than 10μs to prevent power interruption upon battery or wall adapter removal.The LTC1760 implements all elements of a version 1.1 "Smart Battery System Manager" except for the generation of composite battery information. An internal multiplexer cleanly switches the SMBus Host to either of the two attached Smart Batteries without generating partial messages to batteries or SMBus Host. Thermistors on both batteries are automatically monitored for temperature and disconnection information (SafetySignal).ApplicationsPortable Computers and InstrumentsStandalone Dual Smart Battery ChargersBattery Backup Systems

The LTC1771 is a high efficiency current mode step-down DC/DC controller that draws as little as 10µA DC supply current to regulate the output at no load while maintaining high efficiency for loads up to several amps.The LTC1771 drives an external P-channel power MOSFET using a current mode, constant off-time architecture. An external sense resistor is used to program the operating current level. Current mode control provides short-circuit protection, excellent transient response and controlled start-up behavior. Burst Mode operation enables the LTC1771 to maintain high efficiency down to extremely low currents. Shutdown mode further reduces the supply current to a mere 2µA. For low noise applications, Burst Mode operation can be easily disabled with the MODE pin.Wide input supply range of 2.8V to 18V (20V maximum) and 100% duty cycle operation for low dropout make the LTC1771 ideal for a wide variety of battery-powered applications where maximizing battery life is important.The LTC1771’s availability in both 8-lead MSOP and SO packages provides for a minimum area solution.ApplicationsCellular Telephones and Wireless Modems1- to 4-Cell Lithium-Ion-Powered ApplicationsPortable InstrumentsBattery-Powered EquipmentBattery ChargersScanners

The LTC1772 is a constant frequency current mode step-down DC/DC controller providing excellent AC and DC load and line regulation. The device incorporates an accurate undervoltage lockout feature that shuts down the LTC1772 when the input voltage falls below 2.0V.The LTC1772 provides a ±2.5% output voltage accuracy and consumes only 270µA of quiescent current. For applications where efficiency is a prime consideration, the LTC1772 is configured for Burst Mode operation, which enhances efficiency at low output current.To further maximize the life of a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle).In shutdown, the device draws a mere 8µA. High constant operating frequency of 550kHz allows the use of a small external inductor.The LTC1772 is available in a small footprint 6-lead SOT-23.Burst ModeLTC1772YesLTC1772BNoApplicationsOne or Two Lithium-Ion-Powered ApplicationsCellular TelephonesWireless ModemsPortable ComputersDistributed 3.3V, 2.5V or 1.8V Power SystemsScanners

The LTC1772B is a constant frequency current mode step-down DC/DC controller providing excellent AC and DC load and line regulation. The device incorporates an accurate undervoltage lockout feature that shuts down the LTC1772B when the input voltage falls below 2.0V.The LTC1772B provides a ±2.5% output voltage accuracy and consumes only 270µA of quiescent current. In shutdown, the device draws a mere 8µA.To further maximize the life of a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High constant operating frequency of 550kHz allows the use of a small external inductor.The LTC1772B is available in a small footprint 6-lead SOT-23.For a Burst Mode operation enabled version of the LTC1772B, please refer to the LTC1772 data sheet.Burst ModeLTC1772YesLTC1772BNoApplicationsOne or Two Lithium-Ion-Powered ApplicationsCellular TelephonesWireless DevicesPortable ComputersDistributed 3.3V, 2.5V or 1.8V Power Systems