The MAX649/MAX651/MAX652 BiCMOS, step-down DC-DC switching controllers provide high efficiency over three decades of load current. A unique, current-limited pulse-frequency-modulated (PFM) control scheme gives these devices the benefits of pulse-width-modulation (PWM) converters (high efficiency at heavy loads), while using only 100µA of supply current (vs. 2mA to 10mA for PWM converters). The result is high efficiency over loads ranging from 10mA to more than 2.5A.These devices use miniature external components. Their high switching frequency (up to 300kHz) allows for less than 9mm diameter surface-mount inductors.The MAX649/MAX651/MAX652 have dropout voltages less than 1V and accept input voltages up to 16.5V. Output voltages are preset at 5V (MAX649), 3.3V (MAX651), and 3V (MAX652). These controllers can also be adjusted to any voltage from 1.5V to the input voltage by using two resistors.These step-down controllers drive external P-channel MOSFETs at loads greater than 10W. If less power is required, use the MAX639/MAX640/MAX653 step-down converters with on-chip FETs, which allow up to a 225mA load current.Applications5V to 3.3V Green PC ApplicationsBattery-Powered ApplicationsHigh-Efficiency Step-Down RegulationMinimum Component DC-DC Converters

The MAX6520 is the lowest-power 1.2V, precision, three-terminal voltage reference offered in a SOT23-3 package. Ideal for 3V battery-powered equipment where power conservation is critical, the MAX6520 is a low-power alternative to existing two-terminal shunt references. Unlike two-terminal references that throw away battery current and require an external series resistor, the MAX6520 has a 70µA maximum supply current (typically only 50µA) that is independent of the input voltage. This feature translates to maximum efficiency at all battery voltages.The MAX6520 operates from a supply voltage as low as 2.4V, and initial accuracy is ±1% for the SOT23 package.Output voltage temperature coefficient is typically only 25ppm/°C, and is guaranteed to be less than 50ppm/°C in the SOT23 package.ApplicationsBattery-Powered ApplicationsData AcquisitionInstrumentation and Process ControlPortable and Handheld Equipment

The MAX639/MAX640/MAX653 step-down switching regulators provide high efficiency over a wide range of load currents, delivering up to 225mA. A current-limiting pulse-frequency-modulated (PFM) control scheme gives the devices the benefits of pulse-width-modulated (PWM) converters (high efficiency at heavy loads), while using only 10µA of supply current (vs. 2mA to 10mA for PWM converters). The result is high efficiency over a wide range of loads.The MAX639/MAX640/MAX653 input range is 4V to 11.5V, and the devices provide lower preset output voltages of 5V, 3.3V, and 3V, respectively. Or, the output can be user-adjusted to any voltage from 1.3V to the input voltage.The MAX639/MAX640/MAX653 have an internal 1A power MOSFET switch, making them ideal for minimum-component, low- and medium-power applications. For increased output drive capability, use the MAX649/MAX651/MAX652 step-down controllers, which drive an external P-channel FET to deliver up to 5W.Applications5V to 3.3V Conversion9V Battery to 5V, 3.3V, or 3V ConversionHigh-Efficiency Linear Regulator ReplacementPortable Instruments and Handy-Terminals

The MAX6575L/H is a low-cost, low-current temperature sensor with a single-wire digital interface. It features accuracy of ±3°C at +25°C, ±4.5°C at +85°C, and ±5°C at +125°C. The MAX6575L/H is a monostable, externally triggered temperature sensor that allows a microprocessor (µP) to interface with up to eight temperature sensors using a single control line. Temperatures are sensed by measuring the time delay between the falling edge of the external triggering pulse and the falling edge of the subsequent pulse delays reported from the devices. Different sensors on the same I/O line use different timeout multipliers to avoid overlapping signals.The MAX6575L/H features eight different timeout multipliers; these are selectable by using the two time-select pins on each device and choosing the 'L' or 'H' version. The 'L' version provides four delay ranges less than 50ms. The 'H' version provides four delay ranges greater than 50ms. The MAX6575L/H is available in a space-saving 6-pin SOT23 package.ApplicationsBattery PacksCell PhonesCritical µP and µC MonitoringHard Drives/Tape DrivesMedical EquipmentNetworking and Telecom EquipmentPortable Battery-Powered Equipment

The MAX660 monolithic, charge-pump voltage inverter converts a +1.5V to +5.5V input to a corresponding-1.5V to -5.5V output. Using only two low-costcapacitors, the charge pump's 100mA output replaces switching regulators, eliminating inductors and their associated cost, size, and EMI. Greater than 90% efficiency over most of its load-current range combined with a typical operating current of only 120µA provides ideal performance for both battery-powered and board-level voltage conversion applications. The MAX660 can also double the output voltage of an input power supply or battery, providing +9.35V at 100mA from a +5V input.A frequency control (FC) pin selects either 10kHz typ or 80kHz typ (40kHz min) operation to optimize capacitor size and quiescent current. The oscillator frequency can also be adjusted with an external capacitor ordriven with an external clock. The MAX660 is a pin-compatible, high-current upgrade of the ICL7660.The MAX660 is available in both 8-pin DIP and small-outline packages in commercial, extended, and military temperature ranges.For 50mA applications, consider the MAX860/MAX861 pin-compatible devices (also available in ultra-small µMAX packages).ApplicationsHandheld Instruments (PDAs, Palmtops)Interface Power SuppliesLaptop ComputersMedical InstrumentsOperational Amplifier Power Supplies

The MAX660 monolithic, charge-pump voltage inverter converts a +1.5V to +5.5V input to a corresponding-1.5V to -5.5V output. Using only two low-costcapacitors, the charge pump's 100mA output replaces switching regulators, eliminating inductors and their associated cost, size, and EMI. Greater than 90% efficiency over most of its load-current range combined with a typical operating current of only 120µA provides ideal performance for both battery-powered and board-level voltage conversion applications. The MAX660 can also double the output voltage of an input power supply or battery, providing +9.35V at 100mA from a +5V input.A frequency control (FC) pin selects either 10kHz typ or 80kHz typ (40kHz min) operation to optimize capacitor size and quiescent current. The oscillator frequency can also be adjusted with an external capacitor ordriven with an external clock. The MAX660 is a pin-compatible, high-current upgrade of the ICL7660.The MAX660 is available in both 8-pin DIP and small-outline packages in commercial, extended, and military temperature ranges.For 50mA applications, consider the MAX860/MAX861 pin-compatible devices (also available in ultra-small µMAX packages).ApplicationsHandheld Instruments (PDAs, Palmtops)Interface Power SuppliesLaptop ComputersMedical InstrumentsOperational Amplifier Power Supplies

The MAX668/MAX669 constant-frequency, pulse-width modulating (PWM), current-mode DC-DC controllers are designed for a wide range of DC-DC conversion applications including step-up, SEPIC, flyback, and isolated-output configurations. Power levels of 20W or more can be controlled with conversion efficiencies of over 90%. The 1.8V to 28V input voltage range supports a wide range of battery and AC-powered inputs. An advanced BiCMOS design features low operating current (220µA), adjustable operating frequency (100kHz to 500kHz), soft-start, and a SYNC input allowing the MAX668/MAX669 oscillator to be locked to an external clock.DC-DC conversion efficiency is optimized with a low 100mV current-sense voltage as well as with Maxim's proprietary Idle Mode™ control scheme. The controller operates in PWM mode at medium and heavy loads for lowest noise and optimum efficiency, then pulses only as needed (with reduced inductor current) to reduce operating current and maximize efficiency under light loads. A logic-level shutdown input is also included, reducing supply current to 3.5µA.The MAX669, optimized for low input voltages with a guaranteed start-up voltage of 1.8V, requires boot-strapped operation (IC powered from boosted output). It supports output voltages up to 28V. The MAX668 operates with inputs as low as 3V and can be connected in either a bootstrapped or non-bootstrapped (IC powered from input supply or other source) configuration. When not bootstrapped, it has no restriction on output voltage. Both ICs are available in an extremely compact 10-pin µMAX® package.ApplicationsCellular TelephonesLANs and Network SystemsPOS SystemsTelecom Hardware

The MAX6806/MAX6807/MAX6808 precision voltage detectors are ideal for accurate monitoring of power supplies in digital systems. They provide circuit reliability and reduce total cost by eliminating external components and adjustments.The MAX6806/MAX6807/MAX6808 assert a reset signal whenever the supply voltage (VCC) falls below the factory-preset, ±2% accurate threshold. Internal hysteresis ensures stable switching. The MAX6806/MAX6807/MAX6808 are available in 4.6V and 2.6V thresholds (2.3V is also available for the MAX6806 only). The MAX6806 features a push-pull active-low RESET output; the MAX6807 features an active-high, push-pull RESET output; and the MAX6808 features an open-drain, active-low RESET output. Active-low RESET is valid for VCC down to 1V (MAX6806/MAX6808), and RESET (MAX6807) is guaranteed for VCC down to 1.2V.The MAX6806/MAX6807/MAX6808 are available in 3-pin SC70, 3-pin SOT23, 8-pin µMAX®, 8-pin SO, and 4-pin SOT143 packages. The SOT143 package includes a manual-reset input.ApplicationsBar-Code ScannersComputers: Desktop, Workstation, ServerControllersCritical µP and µC Power MonitoringIntelligent InstrumentsPortable Battery-Powered Equipment

The MAX680/MAX681 are monolithic, CMOS, dual charge-pump voltage converters that provide ±10V outputs from a +5V input voltage. The MAX680/MAX681 provide both a positive step-up charge pump to develop +10V from +5V input and an inverting charge pump to generate the -10V output. Both parts have an on-chip, 8kHz oscillator. The MAX681 has the capacitors internal to the package, and the MAX680 requires four external capacitors to produce both positive and negative voltages from a single supply.The output source impedances are typically 150Ω, providing useful output currents up to 10mA. The low quiescent current and high efficiency make this device suitable for a variety of applications that need both positive and negative voltages generated from a single supply.The MAX864/MAX865 are also recommended for new designs. The MAX864 operates at up to 200kHz and uses smaller capacitors. The MAX865 comes in the smaller µMAX® package.Applications±10V from +5V Logic Supply±6V from 3V Lithium CellBattery-Powered ApplicationsData AcquisitionHandheld Instruments (PDAs, Palmtops)Operational Amplifier Power SuppliesPanel Meters

The MAX6816/MAX6817/MAX6818 are single, dual, and octal switch debouncers that provide clean interfacing of mechanical switches to digital systems. They accept one or more bouncing inputs from a mechanical switch and produce a clean digital output after a short, preset qualification delay. Both the switch opening bounce and the switch closing bounce are removed. Robust switch inputs handle ±25V levels and are ±15kV ESD-protected for use in harsh industrial environments. They feature single-supply operation from +2.7V to +5.5V. Undervoltage lockout circuitry ensures the output is in the correct state upon power-up.The single MAX6816 and dual MAX6817 are offered in SOT packages and require no external components. Their low supply current makes them ideal for use in portable equipment.The MAX6818 octal switch debouncer is designed for data-bus interfacing. The MAX6818 monitors switches and provides a switch change-of-state output (active-low CH), simplifying microprocessor (µP) polling and interrupts. Additionally, the MAX6818 has three-state outputs controlled by an enable (active-low EN) pin, and is pin-compatible with the LS573 octal latch (except for the active-low CH pin), allowing easy interfacing to a digital data bus.ApplicationsµP Switch InterfacingIndustrial InstrumentsMembrane KeypadsPC-Based InstrumentsPortable Instrumentation

The MAX6816/MAX6817/MAX6818 are single, dual, and octal switch debouncers that provide clean interfacing of mechanical switches to digital systems. They accept one or more bouncing inputs from a mechanical switch and produce a clean digital output after a short, preset qualification delay. Both the switch opening bounce and the switch closing bounce are removed. Robust switch inputs handle ±25V levels and are ±15kV ESD-protected for use in harsh industrial environments. They feature single-supply operation from +2.7V to +5.5V. Undervoltage lockout circuitry ensures the output is in the correct state upon power-up.The single MAX6816 and dual MAX6817 are offered in SOT packages and require no external components. Their low supply current makes them ideal for use in portable equipment.The MAX6818 octal switch debouncer is designed for data-bus interfacing. The MAX6818 monitors switches and provides a switch change-of-state output (active-low CH), simplifying microprocessor (µP) polling and interrupts. Additionally, the MAX6818 has three-state outputs controlled by an enable (active-low EN) pin, and is pin-compatible with the LS573 octal latch (except for the active-low CH pin), allowing easy interfacing to a digital data bus.ApplicationsµP Switch InterfacingIndustrial InstrumentsMembrane KeypadsPC-Based InstrumentsPortable Instrumentation

The MAX6816/MAX6817/MAX6818 are single, dual, and octal switch debouncers that provide clean interfacing of mechanical switches to digital systems. They accept one or more bouncing inputs from a mechanical switch and produce a clean digital output after a short, preset qualification delay. Both the switch opening bounce and the switch closing bounce are removed. Robust switch inputs handle ±25V levels and are ±15kV ESD-protected for use in harsh industrial environments. They feature single-supply operation from +2.7V to +5.5V. Undervoltage lockout circuitry ensures the output is in the correct state upon power-up.The single MAX6816 and dual MAX6817 are offered in SOT packages and require no external components. Their low supply current makes them ideal for use in portable equipment.The MAX6818 octal switch debouncer is designed for data-bus interfacing. The MAX6818 monitors switches and provides a switch change-of-state output (active-low CH), simplifying microprocessor (µP) polling and interrupts. Additionally, the MAX6818 has three-state outputs controlled by an enable (active-low EN) pin, and is pin-compatible with the LS573 octal latch (except for the active-low CH pin), allowing easy interfacing to a digital data bus.ApplicationsµP Switch InterfacingIndustrial InstrumentsMembrane KeypadsPC-Based InstrumentsPortable Instrumentation

The MAX686 DAC-controlled boost/inverter IC converts a positive input voltage to a positive or negative LCD bias voltage up to +27.5V or -27.5V. The device features an internal N-channel MOSFET switch, programmable current limiting, and an internal 6-bit digital-to-analog converter (DAC) for digital adjustment of the output voltage. It comes in a small 16-pin QSOP package (same size as an 8-pin SO).The MAX686 uses a current-limited, pulse-frequency-modulation (PFM) control scheme to provide high efficiency over a wide range of load conditions. Its high switching frequency (up to 300kHz) allows the use of small external components.An LCDON output allows the LCD bias voltage to be automatically disabled when the display logic voltage is removed, protecting the display. The MAX686 has a +2.7V to +5.5V input voltage range for the IC, and a +0.8V to +27.5V input voltage range for the inductor. Typical quiescent supply current is 65µA. Shutdown current is 1.5µA.The MAX686 offers high-level integration to save space, reduce power consumption, and increase battery life, making it an excellent choice for battery-powered portable equipment. The MAX629 is similar to the MAX686, except that it does not contain a built-in DAC. Both devices have evaluation kits to facilitate designs.ApplicationsNotebook ComputersPalmtop ComputersPDAs and Other Handheld DevicesPortable Data-Collection TerminalsPositive or Negative LCD BiasVaractor Tuning Diode Bias

The MAX690A/MAX692A/MAX802L/MAX802M/MAX805Lreduce the complexity and number of componentsrequired for power-supply monitoring and battery-controlfunctions in microprocessor (µP) systems. They significantlyimprove system reliability and accuracy comparedto separate ICs or discrete components.These parts provide four functions:1) A reset output during power-up, power-down, andbrownout conditions.2) Battery-backup switching for CMOS RAM, CMOSµP, or other low-power logic.3) A reset pulse if the optional watchdog timer has notbeen toggled within 1.6sec.4) A 1.25V threshold detector for power-fail warning orlow-battery detection, or to monitor a power supplyother than +5V.The parts differ in their reset-voltage threshold levelsand reset outputs. The MAX690A/MAX802L/MAX805Lgenerate a reset pulse when the supply voltage dropsbelow 4.65V, and the MAX692A/MAX802M generate areset below 4.40V. The MAX802L/MAX802M guaranteepower-fail accuracies to ±2%. The MAX805L is thesame as the MAX690A except that RESET is providedinstead of active-low RESET.All parts are available in 8-pin DIP and SO packages.The MAX690A/MAX802L are pin compatible with theMAX690 and MAX694. The MAX692A/MAX802M arepin compatible with the MAX692.ApplicationsBattery-Powered Computers/ControllersCritical µP MonitoringIntelligent Instruments

The MAX690A/MAX692A/MAX802L/MAX802M/MAX805Lreduce the complexity and number of componentsrequired for power-supply monitoring and battery-controlfunctions in microprocessor (µP) systems. They significantlyimprove system reliability and accuracy comparedto separate ICs or discrete components.These parts provide four functions:1) A reset output during power-up, power-down, andbrownout conditions.2) Battery-backup switching for CMOS RAM, CMOSµP, or other low-power logic.3) A reset pulse if the optional watchdog timer has notbeen toggled within 1.6sec.4) A 1.25V threshold detector for power-fail warning orlow-battery detection, or to monitor a power supplyother than +5V.The parts differ in their reset-voltage threshold levelsand reset outputs. The MAX690A/MAX802L/MAX805Lgenerate a reset pulse when the supply voltage dropsbelow 4.65V, and the MAX692A/MAX802M generate areset below 4.40V. The MAX802L/MAX802M guaranteepower-fail accuracies to ±2%. The MAX805L is thesame as the MAX690A except that RESET is providedinstead of active-low RESET.All parts are available in 8-pin DIP and SO packages.The MAX690A/MAX802L are pin compatible with theMAX690 and MAX694. The MAX692A/MAX802M arepin compatible with the MAX692.ApplicationsBattery-Powered Computers/ControllersCritical µP MonitoringIntelligent Instruments

The MAX690A/MAX692A/MAX802L/MAX802M/MAX805Lreduce the complexity and number of componentsrequired for power-supply monitoring and battery-controlfunctions in microprocessor (µP) systems. They significantlyimprove system reliability and accuracy comparedto separate ICs or discrete components.These parts provide four functions:1) A reset output during power-up, power-down, andbrownout conditions.2) Battery-backup switching for CMOS RAM, CMOSµP, or other low-power logic.3) A reset pulse if the optional watchdog timer has notbeen toggled within 1.6sec.4) A 1.25V threshold detector for power-fail warning orlow-battery detection, or to monitor a power supplyother than +5V.The parts differ in their reset-voltage threshold levelsand reset outputs. The MAX690A/MAX802L/MAX805Lgenerate a reset pulse when the supply voltage dropsbelow 4.65V, and the MAX692A/MAX802M generate areset below 4.40V. The MAX802L/MAX802M guaranteepower-fail accuracies to ±2%. The MAX805L is thesame as the MAX690A except that RESET is providedinstead of active-low RESET.All parts are available in 8-pin DIP and SO packages.The MAX690A/MAX802L are pin compatible with theMAX690 and MAX694. The MAX692A/MAX802M arepin compatible with the MAX692.ApplicationsBattery-Powered Computers/ControllersCritical µP MonitoringIntelligent Instruments

The MAX690A/MAX692A/MAX802L/MAX802M/MAX805Lreduce the complexity and number of componentsrequired for power-supply monitoring and battery-controlfunctions in microprocessor (µP) systems. They significantlyimprove system reliability and accuracy comparedto separate ICs or discrete components.These parts provide four functions:1) A reset output during power-up, power-down, andbrownout conditions.2) Battery-backup switching for CMOS RAM, CMOSµP, or other low-power logic.3) A reset pulse if the optional watchdog timer has notbeen toggled within 1.6sec.4) A 1.25V threshold detector for power-fail warning orlow-battery detection, or to monitor a power supplyother than +5V.The parts differ in their reset-voltage threshold levelsand reset outputs. The MAX690A/MAX802L/MAX805Lgenerate a reset pulse when the supply voltage dropsbelow 4.65V, and the MAX692A/MAX802M generate areset below 4.40V. The MAX802L/MAX802M guaranteepower-fail accuracies to ±2%. The MAX805L is thesame as the MAX690A except that RESET is providedinstead of active-low RESET.All parts are available in 8-pin DIP and SO packages.The MAX690A/MAX802L are pin compatible with theMAX690 and MAX694. The MAX692A/MAX802M arepin compatible with the MAX692.ApplicationsBattery-Powered Computers/ControllersCritical µP MonitoringIntelligent Instruments

The MAX690A/MAX692A/MAX802L/MAX802M/MAX805Lreduce the complexity and number of componentsrequired for power-supply monitoring and battery-controlfunctions in microprocessor (µP) systems. They significantlyimprove system reliability and accuracy comparedto separate ICs or discrete components.These parts provide four functions:1) A reset output during power-up, power-down, andbrownout conditions.2) Battery-backup switching for CMOS RAM, CMOSµP, or other low-power logic.3) A reset pulse if the optional watchdog timer has notbeen toggled within 1.6sec.4) A 1.25V threshold detector for power-fail warning orlow-battery detection, or to monitor a power supplyother than +5V.The parts differ in their reset-voltage threshold levelsand reset outputs. The MAX690A/MAX802L/MAX805Lgenerate a reset pulse when the supply voltage dropsbelow 4.65V, and the MAX692A/MAX802M generate areset below 4.40V. The MAX802L/MAX802M guaranteepower-fail accuracies to ±2%. The MAX805L is thesame as the MAX690A except that RESET is providedinstead of active-low RESET.All parts are available in 8-pin DIP and SO packages.The MAX690A/MAX802L are pin compatible with theMAX690 and MAX694. The MAX692A/MAX802M arepin compatible with the MAX692.ApplicationsBattery-Powered Computers/ControllersCritical µP MonitoringIntelligent Instruments

The MAX705–MAX708/MAX813L microprocessor (µP) supervisory circuits reduce the complexity and number of components required to monitor power-supply and battery functions in µP systems. These devices significantly improve system reliability and accuracy compared to separate ICs or discrete components.The MAX705/MAX706/MAX813L provide four functions:A reset output during power-up, power-down, and brownout conditions.An independent watchdog output that goes low if the watchdog input has not been toggled within 1.6 seconds.A 1.25V threshold detector for power-fail warning, low-battery detection, or for monitoring a power supply other than +5V.An active-low manual-reset input.The MAX707/MAX708 are the same as the MAX705/MAX706, except an active-high reset is substituted for the watchdog timer. The MAX813L is the same as the MAX705, except RESET is provided instead of active-low RESET.Two supply-voltage monitor levels are available: The MAX705/MAX707/MAX813L generate a reset pulse when the supply voltage drops below 4.65V, while the MAX706/MAX708 generate a reset pulse below 4.40V. All four parts are available in 8-pin DIP, SO and µMAX® packages.ApplicationsComputersControllersCritical µP Power MonitoringIntelligent Instruments

The MAX705–MAX708/MAX813L microprocessor (µP) supervisory circuits reduce the complexity and number of components required to monitor power-supply and battery functions in µP systems. These devices significantly improve system reliability and accuracy compared to separate ICs or discrete components.The MAX705/MAX706/MAX813L provide four functions:A reset output during power-up, power-down, and brownout conditions.An independent watchdog output that goes low if the watchdog input has not been toggled within 1.6 seconds.A 1.25V threshold detector for power-fail warning, low-battery detection, or for monitoring a power supply other than +5V.An active-low manual-reset input.The MAX707/MAX708 are the same as the MAX705/MAX706, except an active-high reset is substituted for the watchdog timer. The MAX813L is the same as the MAX705, except RESET is provided instead of active-low RESET.Two supply-voltage monitor levels are available: The MAX705/MAX707/MAX813L generate a reset pulse when the supply voltage drops below 4.65V, while the MAX706/MAX708 generate a reset pulse below 4.40V. All four parts are available in 8-pin DIP, SO and µMAX® packages.ApplicationsComputersControllersCritical µP Power MonitoringIntelligent Instruments