Analog Devices

The LTC2937 is a 6-channel power supply sequencer and voltage supervisor. Supplies are enabled or disabled with precise user controlled order and time spacing. To detect power supply output faults during sequencing and monitoring, the LTC2937 accurately monitors supply turn-on/-off delays and output voltage levels. In the event of a fault, response actions include complete power supply shutdown and optional restarts. Root cause of power faults are logged to EEPROM. For systems with high supply count, a simple single wire connection between multiple LTC2937 devices allows sequencing expansion to 300 supplies. After successful sequencing and supply voltage stabilization, the reset output pulls high to initiate microprocessor or other system activity. To accommodate supply margin testing, the reset output can be disabled. Upon supply turn-off, integrated current sources are available as needed to discharge slowly decaying supplies. Configuration EEPROM supports autonomous operation without software.ApplicationsNetwork ServersData Storage SystemsTelecom EquipmentHigh Availability Computer Systems

The LTC2938/LTC2939 are configurable supply monitors for systems with up to four or six supply voltages that need watchdog supervision. One of sixteen preset or adjustable voltage monitor combinations can be selected using an external resistive divider connected to the program input. The preset voltage thresholds are accurate to ±1.5% over temperature. The LTC2938 and LTC2939 also feature adjustable inputs with a 0.5V nominal threshold.The reset and watchdog timeout periods are adjustable using external capacitors. Tight voltage threshold accuracy and glitch immunity ensure reliable reset operation without false triggering. TheRSToutput is guaranteed to be in the correct state for VCCdown to 1V. Each status output has a weak internal pull-up and may be externally pulled up to a user-defined voltage.The 80μA supply current makes the LTC2938 and LTC2939 ideal for power conscious systems. The LTC2939 monitors up to six supplies and the LTC2938 monitors up to four supplies.ApplicationsDesktop and Notebook ComputersMultivoltage SystemsTelecom EquipmentNetwork ServersAutomotive Control Systems

The LTC2938/LTC2939 are configurable supply monitors for systems with up to four or six supply voltages that need watchdog supervision. One of sixteen preset or adjustable voltage monitor combinations can be selected using an external resistive divider connected to the program input. The preset voltage thresholds are accurate to ±1.5% over temperature. The LTC2938 and LTC2939 also feature adjustable inputs with a 0.5V nominal threshold.The reset and watchdog timeout periods are adjustable using external capacitors. Tight voltage threshold accuracy and glitch immunity ensure reliable reset operation without false triggering. TheRSToutput is guaranteed to be in the correct state for VCCdown to 1V. Each status output has a weak internal pull-up and may be externally pulled up to a user-defined voltage.The 80μA supply current makes the LTC2938 and LTC2939 ideal for power conscious systems. The LTC2939 monitors up to six supplies and the LTC2938 monitors up to four supplies.ApplicationsDesktop and Notebook ComputersMultivoltage SystemsTelecom EquipmentNetwork ServersAutomotive Control Systems

The LTC2941 measures battery charge state in battery-supplied handheld PC and portable product applications. Its operating range is perfectly suited for single-cell Li-Ion batteries. A precision coulomb counter integrates current through a sense resistor between the battery’s positive terminal and the load or charger. The measured charge is stored in internal registers. An SMBus/I2C interface accesses and configures the device.The LTC2941 features programmable high and low thresholds for accumulated charge. If a threshold is exceeded, the device communicates an alert using either the SMBus alert protocol or by setting a flag in the internal status register.The LTC2941 requires only a single low value external sense resistor to set the current range.Integrated Sense ResistorLTC2941NoLTC2941-1YesApplicationsLow Power Handheld ProductsCellular PhonesMP3 PlayerCamerasGPS

The LTC2942-1 measures battery charge state, battery voltage and chip temperature in handheld PC and portable product applications. Its operating range is perfectly suited for single cell Li-Ion batteries. A precision coulomb counter integrates current through an internal sense resistor between the battery’s positive terminal and the load or charger. Battery voltage and on-chip temperature are measured with an internal 14-bit No Latency ΔΣ™ADC. The three measured quantities (charge, voltage and temperature) are stored in internal registers accessible via the onboard SMBus/I2C interface.The LTC2942-1 features programmable high and low thresholds for all three measured quantities. If a programmed threshold is exceeded, the device communicates an alert using either the SMBus alert protocol or by setting a flag in the internal status register.Integrated Sense ResistorLTC2942NoLTC2942-1YesApplicationsLow Power Handheld ProductsCellular PhonesMP3 PlayersCamerasGPS

The LTC2943 measures battery charge state, battery voltage, battery current and its own temperature in portable product applications. The wide input voltage range allows use with multicell batteries up to 20V. A precision coulomb counter integrates current through a sense resistor between the battery’s positive terminal and the load or charger. Voltage, current and temperature are measured with an internal 14-bit No Latency ΔΣ™ADC. The measurements are stored in internal registers accessible via the onboard I2C/SMBus Interface.The LTC2943 features programmable high and low thresholds for all four measured quantities. If a programmed threshold is exceeded, the device communicates an alert using either the SMBus alert protocol or by setting a flag in the internal status register. The LTC2943 requires only a single low value sense resistor to set the measured current range.ApplicationsPower ToolsElectric BicyclesPortable Medical EquipmentVideo Cameras

The LTC2944 measures battery charge state, battery voltage, battery current and its own temperature in portable product applications. The wide input voltage range allows use with multicell batteries up to 60V. A precision coulomb counter integrates current through a sense resistor between the battery’s positive terminal and the load or charger. Voltage, current and temperature are measured with an internal 14-bit No Latency ΔΣ™ADC. The measurements are stored in internal registers accessible via the on-board I2C/SMBus Interface.The LTC2944 features programmable high and low thresholds for all four measured quantities. If a programmed threshold is exceeded, the device communicates an alert using either the SMBus alert protocol or by setting a flag in the internal status register. The LTC2944 requires only a single low value sense resistor to set the measured current range.ApplicationsElectric and Hybrid Electric VehiclesPower ToolsElectric Bicycles, Motorcycles, ScootersHigh Power Portable EquipmentPhoto VoltaicsBackup Battery Systems

The LTC2945 is a rail-to-rail system monitor that measures current, voltage, and power. It features an operating range of 2.7V to 80V and includes a shunt regulator for supplies above 80V to allow flexibility in the selection of input supply. The current measurement range of 0V to 80V is independent of the input supply. An onboard 0.75% accurate 12-bit ADC measures load current, input voltage and an auxiliary external voltage. A 24-bit power value is generated by digitally multiplying the measured 12-bit load current and input voltage data. Minimum and maximum values are stored and an overrange alert with programmable thresholds minimizes the need for software polling. Data is reported via a standard I2C interface. Shutdown mode reduces power consumption to 20μA.The LTC2945 I2C interface includes separate data input and output pins for use with standard or opto-isolated I2C connections. The LTC2945-1 has an inverted data output for use with inverting opto-isolator configurations.APPLICATIONSTelecom InfrastructureIndustrialAutomotiveConsumer

The LTC2947-65 is a high precision power and energy monitor with an internal sense resistor supporting up to ±65A*. Three internal No Latency Δ∑™ ADCs ensure accurate measurement of voltage and current, while highbandwidth analog multiplication of voltage and current provides accurate power measurement in a wide range of applications. Internal or external clocking options enable precise charge and energy measurements.An internal 150µΩ, temperature-compensated sense resistor minimizes efficiency loss and external components, simplifying energy measurement applications while enabling high accuracy current measurement over the full temperature range.All measured quanities are stored in internal registers accessible via the selectable I2C/SPI interface. The LTC2947-65 features programmable high and low thresholds for all measured quantities to reduce digital traffic with the host.ApplicationsServersTelecom InfrastructureIndustrialElectric VehiclesPhotovoltaics