The MAX6381–MAX6390 microprocessor (µP) supervisory circuits monitor power-supply voltages from +1.8V to +5.0V while consuming only 3µA of supply current at +1.8V. Whenever VCC falls below the factory-set reset thresholds, the reset output asserts and remains asserted for a minimum reset timeout period after VCC rises above the reset threshold. Reset thresholds are available from +1.58V to +4.63V, in approximately 100mV increments. Seven minimum reset timeout delays ranging from 1ms to 1200ms are available.The MAX6381/MAX6384/MAX6387 have a push-pull active-low reset output. The MAX6382/MAX6385/MAX6388 have a push-pull active-high reset output, and the MAX6383/MAX6386/MAX6389/MAX6390 have an open-drain active-low reset output. The MAX6384/MAX6385/MAX6386 also feature a debounced manual reset input (with internal pullup resistor). The MAX6387/MAX6388/MAX6389 have an auxiliary input for monitoring a second voltage. The MAX6390 offers a manual reset input with a longer VCC reset timeout period (1120ms or 1200ms) and a shorter manual reset timeout (140ms or 150ms).The MAX6381/MAX6382/MAX6383 are available in 3-pin SC70 and 6-pin µDFN packages and the MAX6384–MAX6390 are available in 4-pin SC70 and 6-pin µDFN packages.ApplicationsComputersControllersCritical µP and µC Power MonitoringDual Voltage SystemsIntelligent InstrumentsPortable Battery-Powered Equipment

The MXD1810–MXD1813/MXD1815–MXD1818 family of microprocessor (µP) reset circuits monitor power supplies in µP and digital systems. These devices provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +2.5V/+3.0V/+3.3V (MXD1815–MXD1818), and +5V (MXD1810–MXD1813) systems.These circuits assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping reset asserted for at least 100ms after VCC rises above the reset threshold. The MXD1813/MXD1818 also keep reset asserted for at least 100ms after the output is momentarily pulled to GND by an external push-button switch.The MXD1812/MXD1817 have an active-high push-pull RESET output. The MXD1810/MXD1815 (push-pull) and MXD1811/MXD1813/MXD1816/MD1818 (open-drain) have an active-low RESET output. The open-drain devices (MXD1811/MXD1813/MXD1816/MXD1818) have an internal pullup resistor to VCC. The MXD1813/MXD1818 feature a debounced manual reset feature that asserts a reset if the active-low RESET pin is pulled low for more than 1.5µs. When used to initiate manual reset, active-low RESET debounces signals from devices such as mechanical switches. For devices with this feature, the release of the external switch triggers the reset period. The MXD1810–MXD1813/MXD1815–MXD1818 are guaranteed to output the correct logic state for VCC down to +1V. These ICs provide a reset comparator designed to ignore fast transients on VCC. Reset thresholds are available between +2.18V and +4.62V. These small, low-power (4µA) devices are ideal for use in portable equipment. All are available in space-saving 3-pin SC70 and SOT23 packages, and are specified from -40°C to +105°C.ApplicationsComputers and ControllersCritical µP and µC MonitoringIntelligent InstrumentsPortable Battery-Powered EquipmentPrintersSet-Top Boxes

The MAX6736–MAX6745 are low-power dual-/triple-voltage microprocessor (µP) supervisors. These devices assert a reset if any monitored supply falls below its factory-trimmed or adjustable threshold and maintain reset for a minimum timeout period after all supplies rise above their thresholds. The integrated dual/triple supervisory circuits significantly reduce size and power compared to separate ICs or discrete components. The low supply current of 6µA makes these devices ideal for portable equipment.The MAX6736/MAX6737 are dual fixed-voltage µP supervisors with a manual reset input. The MAX6738/MAX6739 have one fixed and one adjustable reset threshold and a manual reset input. The MAX6740/MAX6743 are triple-voltage µP supervisors with two fixed and one user-adjustable reset threshold inputs. The MAX6741/MAX6744 are dual-voltage µP supervisors with a power-OK (POK) output ideal for power-supply sequencing. The MAX6742/MAX6745 monitor the primary VCC supply and have an independent power-fail comparator.The MAX6736–MAX6745 monitor I/O supply voltages (VCC1) from 1.8V to 5.0V and core supply voltages (VCC2) from 0.9V to 3.3V with factory-trimmed reset threshold voltage options (Table 1). An external adjustable RSTIN input option allows monitoring voltages down to 0.5V.A variety of push-pull or open-drain reset outputs along with manual reset input and power-fail input/output features are available (see the Selector Guide). The MAX6736–MAX6745 are offered in a space-saving 5-pin SC70 package and operate over the -40°C to +85°C temperature range.ApplicationsControllersGPS EquipmentMultivoltage SystemsNotebook ComputersPDAsPortable Battery-Powered EquipmentPOS Equipment

The MAX6746–MAX6753 low-power microprocessor (µP) supervisory circuits monitor single/dual system supply voltages from 1.575V to 5V and provide maximum adjustability for reset and watchdog functions. These devices assert a reset signal whenever the VCC supply voltage or RESET IN falls below its reset threshold or when manual reset is pulled low. The reset output remains asserted for the reset timeout period after VCC and RESET IN rise above the reset threshold. The reset function features immunity to power-supply transients.The MAX6746–MAX6753 have ±2% factory-trimmed reset threshold voltages in approximately 100mV increments from 1.575V to 5.0V and/or adjustable reset threshold voltages using external resistors.The reset and watchdog delays are adjustable with external capacitors. The MAX6746–MAX6751 contain a watchdog select input that extends the watchdog timeout period by 128x. The MAX6752/MAX6753 contain a window watchdog timer that looks for activity outside an expected window of operation.The MAX6746–MAX6753 are available with a push-pull or open-drain active-low RESET output. The MAX6746–MAX6753 are available in an 8-pin SOT23 package and are fully specified over the automotive temperature range (-40°C to +125°C). Design Solution: Build in Automotive Insurance with Supervisor andWatchdog Policies ›ApplicationsAutomotiveBattery-Powered Computers/ControllersComputersCritical µP MonitoringEmbedded ControllersIntelligent InstrumentsMedical EquipmentPortable EquipmentSet-Top Boxes

The MAX6746–MAX6753 low-power microprocessor (µP) supervisory circuits monitor single/dual system supply voltages from 1.575V to 5V and provide maximum adjustability for reset and watchdog functions. These devices assert a reset signal whenever the VCC supply voltage or RESET IN falls below its reset threshold or when manual reset is pulled low. The reset output remains asserted for the reset timeout period after VCC and RESET IN rise above the reset threshold. The reset function features immunity to power-supply transients.The MAX6746–MAX6753 have ±2% factory-trimmed reset threshold voltages in approximately 100mV increments from 1.575V to 5.0V and/or adjustable reset threshold voltages using external resistors.The reset and watchdog delays are adjustable with external capacitors. The MAX6746–MAX6751 contain a watchdog select input that extends the watchdog timeout period by 128x. The MAX6752/MAX6753 contain a window watchdog timer that looks for activity outside an expected window of operation.The MAX6746–MAX6753 are available with a push-pull or open-drain active-low RESET output. The MAX6746–MAX6753 are available in an 8-pin SOT23 package and are fully specified over the automotive temperature range (-40°C to +125°C). Design Solution: Build in Automotive Insurance with Supervisor andWatchdog Policies ›ApplicationsAutomotiveBattery-Powered Computers/ControllersComputersCritical µP MonitoringEmbedded ControllersIntelligent InstrumentsMedical EquipmentPortable EquipmentSet-Top Boxes

The MAX6746–MAX6753 low-power microprocessor (µP) supervisory circuits monitor single/dual system supply voltages from 1.575V to 5V and provide maximum adjustability for reset and watchdog functions. These devices assert a reset signal whenever the VCC supply voltage or RESET IN falls below its reset threshold or when manual reset is pulled low. The reset output remains asserted for the reset timeout period after VCC and RESET IN rise above the reset threshold. The reset function features immunity to power-supply transients.The MAX6746–MAX6753 have ±2% factory-trimmed reset threshold voltages in approximately 100mV increments from 1.575V to 5.0V and/or adjustable reset threshold voltages using external resistors.The reset and watchdog delays are adjustable with external capacitors. The MAX6746–MAX6751 contain a watchdog select input that extends the watchdog timeout period by 128x. The MAX6752/MAX6753 contain a window watchdog timer that looks for activity outside an expected window of operation.The MAX6746–MAX6753 are available with a push-pull or open-drain active-low RESET output. The MAX6746–MAX6753 are available in an 8-pin SOT23 package and are fully specified over the automotive temperature range (-40°C to +125°C). Design Solution: Build in Automotive Insurance with Supervisor andWatchdog Policies ›ApplicationsAutomotiveBattery-Powered Computers/ControllersComputersCritical µP MonitoringEmbedded ControllersIntelligent InstrumentsMedical EquipmentPortable EquipmentSet-Top Boxes

The MAX6832–MAX6840 are microprocessor (µP) supervisory circuits used to monitor low-voltage power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +1.2V to +1.8V powered circuits.These devices assert a reset signal whenever the VCC supply voltage declines below a preset threshold or whenever manual reset (active-low MR) is asserted. Reset remains asserted for a fixed timeout delay after VCC has risen above the reset threshold or when manual reset is deasserted. Five different timeout periods are available: 70µs (voltage detector), 1.5ms, 30ms, 210ms, and 1.68s. Reset thresholds suitable for operation with a variety of supply voltages are available.The MAX6832/MAX6835/MAX6838 have a push-pull active-low reset output (active-low RESET). The MAX6833/MAX6836/MAX6839 have a push-pull active-high reset output (RESET) and the MAX6834/MAX6837/MAX6840 have an open-drain active-low reset output (active-low RESET). The open-drain active-low reset output requires a pullup resistor that can be connected to a voltage higher than VCC.The MAX6835/MAX6836/MAX6837 feature a debounced manual reset input (active-low MR), while the MAX6838/MAX6839/MAX6840 provide a RESET-IN input allowing the user to externally adjust the reset threshold. The reset comparator is designed to ignore fast transients on VCC.Low supply current of 7.5µA makes the MAX6832–MAX6840 ideal for use in portable equipment. These devices are available in 3- and 4-pin SC70 packages.ApplicationsComputers: Desktop, Workstation, ServerControllersCritical µP and µC Power MonitoringIntelligent InstrumentsPortable Battery-Powered Equipment

The MAX8537/MAX8539 controllers provide a complete power-management solution for both double-data-rate (DDR) and combiner supplies. The MAX8537 and MAX8539 are configured for out-of-phase and in-phase DDR power-supply operations, respectively, and generate three outputs: the main memory voltage (VDDQ), the tracking sinking/sourcing termination voltage (VTT), and the termination reference voltage (VTTR). The MAX8538 is configured as a dual out-of-phase controller for point-of-load supplies. Each buck controller can source or sink up to 25A of current, while the termination reference can supply up to 15mA output.The MAX8537/MAX8538/MAX8539 use constant-frequency voltage-mode architecture with operating frequencies of 200kHz to 1.4MHz. An internal high- bandwidth (25MHz) operational amplifier is used as an error amplifier to regulate the output voltage. This allows fast transient response, reducing the number of output capacitors. An all-N-FET design optimizes efficiency and cost. The MAX8537/MAX8538/MAX8539 have a 1% accurate reference. The second synchronous buck controller in the MAX8537/MAX8539 and the VTTR amplifier generate 1/2 VDDQ voltage for VTT and VTTR, and track the VDDQ within ±1%.This family of controllers uses a high-side current-sense architecture for current limiting. ILIM pins allow the setting of an adjustable, lossless current limit for different combinations of load current and RDSON. Alternately, more accurate overcurrent limit is achieved by using a sense resistor in series with the high-side FET. Overvoltage protection is achieved by latching off the high-side MOSFET and latching on the low-side MOSFET when the output voltage exceeds 17% of its set output. Independent enable, power-good, and soft-start features enhance flexibility.ApplicationsBroadband RoutersDDR Memory Power SuppliesNetworking SystemsNotebooks and DesknotesPower Combiner in Advanced VGA CardsPower DSP Core SuppliesRAMBUS Memory Power SuppliesServers and Storage SystemsxDSL Modems and Routers

The MAX803/MAX809/MAX810 are microprocessor (µP) supervisory circuits used to monitor the power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V, +3.3V, +3.0V, or +2.5V powered circuits.These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available.The MAX803 has an open-drain output stage, while the MAX809/MAX810 have push-pull outputs. The MAX803's open-drain active-low RESET output requires a pullup resistor that can be connected to a voltage higher than VCC. The MAX803/MAX809 have an active-low RESET output, while the MAX810 has an active-high RESET output. The reset comparator is designed to ignore fast transients on VCC, and the outputs are guaranteed to be in the correct logic state for VCC down to 1V.Low supply current makes the MAX803/MAX809/MAX810 ideal for use in portable equipment. The MAX803 is available in a 3-pin SC70 package, and the MAX809/MAX810 are available in 3-pin SC70 or SOT23 packages.ApplicationsAutomotiveComputers: Desktop, Workstation, ServerControllersCritical µP and µC Power MonitoringIntelligent InstrumentsPortable Battery-Powered Equipment

The LT®1070/LT1071 are monolithic high power switching regulators. They can be operated in all standard switching configurations including buck, boost, flyback, forward,inverting and “Cuk”. A high current, high efficiency switch is included on the die along with all oscillator,control and protection circuitry. Integration of all functions allows the LT1070/LT1071 to be built in a standard 5-pin T0-220 power package. This makes it extremely easy to use and provides “bust proof” operation similar to that obtained with 3-pin linear regulators.The LT1070/LT1071 operate with supply voltages from 3Vto 60V, and draw only 6mA quiescent current. They can deliver load power up to 100W with no external power devices. By utilizing current mode switching techniques,they provide excellent AC and DC load and line regulation.The LT1070/LT1071 have many unique features not found even on the vastly more difficult to use low power control chips presently available. They use adaptive antisat switch drive to allow very wide ranging load currents with no loss in efficiency. An externally activated shutdown mode reduces total supply current to 50µA typical for standby operation. Totally isolated and regulated outputs can be generated by using the optional “flyback regulation mode” built into the LT1070/LT1071, without the need for optocouplers or extra transformer windings.Applications Logic Supply 5V at 10A 5V Logic to ± 15V Op Amp Supply Offline Converter up to 200W Battery Upconverter Power Inverter (+ to -) or (- to +) Fully Floating Multiple Outputs For Lower Current Applications, See the LT1072