Analog Devices Inc./Maxim Integrated

MAX17625 and MAX17626 are high-frequency synchronous step-down DC-DC converters with integrated MOSFETs and compensation components that operate over a 2.7V to 5.5V input-voltage range. MAX17625 and MAX17626 support up to 700mA load current and allow the use of small, low-cost input and output capacitors. The output voltage can be adjusted from 0.8V to 3.3V.When the EN pin is asserted, an internal power-up sequence ramps up the error-amplifier reference, resulting in output-voltage soft-start. The FB pin monitors the output voltage through a resistor-divider. The devices select either PFM or forced-PWM mode depending on the state of the MODE pin at power-up. By pulling the EN pin to low, the devices enter shutdown mode and consume only 0.1µA (typ) of standby current.The devices use an internally compensated, fixed-frequency, peak-current mode control scheme. On the falling edge of an internal clock, the high-side pMOSFET turns on and continues to be on during normal operation until at least the rising edge of the clock (for 40ns). An internal error amplifier compares the feedback voltage to a fixed internal reference voltage and generates an error voltage. The error voltage is compared to the sum of the current-sense voltage and the slope-compensation voltage by the PWM comparator to set the on-time. During the on-time of the pMOSFET, the inductor current ramps up. For the remainder of the switching period (off-time), the pMOSFET is kept off and the low-side nMOSFET turns on. During the off-time, the inductor releases the stored energy as the inductor current ramps down, providing current to the output. Under overload conditions, the cycle-by-cycle current-limit feature limits the inductor peak current by turning off the high-side pMOSFET and turning on the low-side nMOSFET.ApplicationsFactory AutomationPersonal ElectronicsPoint-of-Load Power Supply

The MAX1763 is a high-efficiency, low-noise, step-up DC-DC converter intended for use in battery-powered wireless applications. This device maintains exceptionally low quiescent supply current (110µA) despite its high 1MHz operating frequency. Small external components and a tiny package make this device an excellent choice for small hand-held applications that require the longest possible battery life.The MAX1763 uses a synchronous-rectified pulse-width-modulation (PWM) boost topology to generate 2.5V to 5.5V outputs from a wide range of input sources, such as one to three alkaline or NiCd/NiMH cells or a single Lithium-ion (Li+) cell. Maxim's proprietary Idle Mode™ circuitry significantly improves efficiency at light load currents while smoothly transitioning to fixed-frequency PWM operation at higher load currents to maintain excellent full-load efficiency. Low-noise, forced-PWM mode is available for applications that require constant-frequency operation at all load currents. The MAX1763 may also be synchronized to an external clock to protect sensitive frequency bands in communications equipment.The MAX1763 includes an on-chip linear gain block that can be used to build a high-power external linear regulator or as a low-battery comparator. Soft-start and current limit functions permit optimization of efficiency, external component size, and output voltage ripple.The MAX1763 is available in a space-saving 16-pin QSOP package or a high-power (1.5W) 16-pin TSSOP-EP package.ApplicationsDigital Cordless PhonesHandheld Instruments (PDAs, Palmtops)Palmtop ComputersPCS PhonesPersonal CommunicatorsWireless Handsets

The Himalaya series of voltage regulator ICs, power modules, and chargers enable cooler, smaller, and simpler power supply solutions. The MAX17633 is a high-efficiency, high-voltage, Himalaya synchronous step-down DC-DC converter with integrated MOSFETs operating over an input voltage range of 4.5V to 36V. It can deliver up to 3.5A current. The MAX17633 is available in three variants MAX17633A, MAX17633B, and MAX17633C. The MAX17633A and MAX17633B are the fixed 3.3V and fixed 5V output voltage parts, respectively. MAX17633C is an adjustable output voltage (from 0.9V up to 90% of VIN) part. Built-in compensation across the output voltage range eliminates the need for external components.The MAX17633 features peak-current-mode control architecture. The device can be operated in the forced pulse-width modulation (PWM), pulse-frequency modulation (PFM), or discontinuous-conduction mode (DCM) to enable high efficiency under full-load and light-load conditions.The feedback-voltage-regulation accuracy over -40°C to +125°C for the MAX17633A, MAX17633B, and MAX17633C is ±1.3%. Simulation models are available.ApplicationsBase-Station Power SuppliesDistributed Supply RegulationGeneral-Purpose Point-of-LoadHigh-Voltage Single-Board SystemsIndustrial Control Power SuppliesWall Transformer Regulation

The MAX17634x is a high-efficiency, high-voltage, synchronous step-down DC-DC converter with integrated MOSFETs operating over an input-voltage range of 4.5V to 36V. It can deliver up to 4.25A current. The MAX17634 is available in three variants: MAX17634A, MAX17634B, and MAX17634C. The MAX17634A and MAX17634B are fixed 3.3V and fixed 5V output voltage parts, respectively. The MAX17634C is an adjustable output voltage (from 0.9V up to 90% of VIN) part. Built-in compensation across the output voltage range eliminates the need for external components.The MAX17634x features peak-current-mode control architecture. The device can be operated in forced pulse-width modulation (PWM), pulse-frequency modulation (PFM), or discontinuous-conduction mode (DCM) to enable high efficiency under full-load and lightload conditions. The MAX17634x offers a low minimum on time that allows high switching frequencies and a smaller solution size.The feedback voltage regulation accuracy over -40°C to +125°C for the MAX17634x is ±1.3%.The device is available in a compact 20-pin (4mm x 4mm) TQFN package. Simulation models are available.ApplicationsIndustrial Control Power SuppliesGeneral-Purpose Point-of-LoadDistributed Supply RegulationBase Station Power SuppliesWall Transformer RegulationHigh-Voltage, Single-Board Systems

The Himalaya series of voltage regulator ICs, power modules, and chargers enable cooler, smaller, and simpler power-supply solutions. The MAX17640 family of products are high-efficiency, high-voltage, Himalaya synchronous DC-DC converters with integrated MOSFETs operating over a wide input-voltage range of 4.5V to 60V.The converters can deliver up to 400mA and generate output voltages from 0.9V to 0.89 x VIN; MAX17640A fixed at 3.3V, MAX17640B fixed at 5.0V, and MAX17640C is adjustable. The family of converters is available in a compact, 8-pin, TDFN (2mm x 2mm) package.The device employs a peak-current-mode control architecture with a MODE pin that can be used to operate the device in pulse-width modulation (PWM) or pulse-frequency modulation (PFM) control schemes. PWM operation provides constant frequency operation at all loads and is useful in applications sensitive to variable switching frequency. PFM operation disables negative inductor current and additionally skips pulses at light loads for high-efficiency. The low-resistance on-chip MOSFETs ensure high-efficiency at full load and simplify the PCB layout.To reduce input inrush current, the device offers an internal soft-start. The device also incorporates an EN/UVLO pin that allows the user to turn on the part at the desired input voltage level.ApplicationsIndustrial Sensors4–20mA Current LoopsHVAC and Building ControlHigh-Voltage LDO ReplacementGeneral Purpose Point-of-Load

The Himalaya series of voltage regulator ICs, power modules, and chargers enable cooler, smaller, and simpler power-supply solutions. The MAX17643 high-efficiency, high-voltage, Himalaya synchronous step-down DC-DC converter with integrated MOSFETs operates over a 4.5V to 60V input. The converter can deliver up to 2A and generates output voltages from 0.9V up to (0.9 x VIN)V. The feedback (FB) voltage is accurate to within ±1.4% over -40°C to +125°C. Built-in compensation across the output- voltage range eliminates the need for external components. The MAX17643 features peak-current-mode control architecture and operates in fixed frequency forced PWM mode. The current-limit settings of the MAX17643 allow the device to supply load-current peaks up to 2A. This allows the device to support pulsed load applications such as communication modules with minimal output-voltage droop. The MAX17643 offers a low minimum on-time that allows high switching frequencies and a smaller solution size.The device is available in a 12-pin (3mm × 3mm) TDFN package. Simulation models are available.ApplicationsIndustrial-Control Power SuppliesGeneral-Purpose Point-of-LoadDistributed Supply RegulationBase-Station Power SuppliesWall Transformer RegulationHigh-Voltage, Single-Board SystemsPulsed-Load ApplicationsCommunication Modules