Analog Devices Inc./Maxim Integrated

The MAX1749 allows for a constant vibration force while operating from a +2.5V to +6.5V input range and delivering up to 120mA. A PMOS pass transistor allows the 80µA supply current to remail independent of the load.The output voltage can be adjusted from +1.25V to VINwith an external resistor-divider. When turned off (ON = low), the MAX1749 supply current drops to 1µA (max) to minimize battery drain. Other features include short-circuit protection, thermal shutdown protection, and reverse battery protection. The MAX1749 is available in a 5-pin SOT23 package.ApplicationsPager Vibrator Motor DriversWireless Handset Vibrator Motor Drivers

The MAX17491 is a single-phase synchronous noninverting MOSFET driver. The MAX17491 is intended to work with controller ICs like the MAX8736, MAX8786, or MAX17030 in multiphase notebook CPU core regulators.The regulators can either step down directly from the battery voltage to create the core voltage or step down from the main system supply. The single-stage conversion method allows the highest possible efficiency, while the 2-stage conversion at higher switching frequency provides the minimum possible physical size.The low-side driver is optimized to drive 3nF capacitive loads with 4ns/8ns typical fall/rise times, and the high-side driver with 8ns/10ns typical fall/rise times. Adaptive dead-time control prevents shoot-through currents and maximizes converter efficiency.The MAX17491 features improved zero crossing and UVLO performance over the MAX8791/MAX8791B.The MAX17491 is available in a small, lead-free, 8-pin, 3mm x 3mm, TQFN package.ApplicationsCPU Core Power SuppliesMultiphase Step-Down ConvertersNotebooks/Desktops/Servers

The MAX17497A/MAX17497B include both a current-mode fixed-frequency flyback converter and a synchronous step-down regulator. They contain all the control circuitry required to design wide input-voltage nonisolated power supplies to supply multiple output rails for smart meters, industrial control, and other similar applications. The MAX17497A has its rising/falling undervoltage lockout (UVLO) thresholds optimized for universal offline (85V AC to 265V AC) applications, while the MAX17497B supports undervoltage lockout (UVLO) thresholds suitable to low-voltage DC-DC applications. Both devices also include a 3.3V fixed-output synchronous step-down regulator that delivers up to 600mA load current.The switching frequency of the MAX17497A flyback converter is 250kHz, while the MAX17497B flyback/ boost converter is 500kHz. The internally compensated synchronous step-down regulator switches at 1MHz on both versions. These frequencies allow the use of tiny magnetic and filter components resulting in compact, cost-effective power supplies. An EN/UVLO input allows the user to start the power supply precisely at the desired input voltage, while also functioning as an on/off pin. The OVI pin enables implementation of an input overvoltage-protection scheme that ensures the converter shuts down when the DC input voltage exceeds the desired maximum value.Programmable current limit allows proper sizing and protection of the primary switching FET. The devices support a maximum duty cycle greater than 92% and provides programmable slope compensation to allow optimization of control-loop performance. The devices provide an open-drain RESETN pin that serves as a power-good indicator and enters the high-impedance state to indicate that the flyback/boost converter and 3.3V step-down regulator outputs are in regulation. An SSF pin allows programmable soft-start time for the flyback/boost converter, while an internal digital soft-start is employed for the 3.3V step-down regulator to limit inrush current. Hiccup mode overcurrent protection and thermal shutdown are provided to minimize dissipation under overcurrent and overtemperature fault conditions. The devices are available in a space-saving 16-pin (3mm x 3mm) TQFN package with 0.5mm lead spacing.ApplicationsAC/DC Power Supplies for Smart Meter ApplicationsUniversal-Input Offline AC-DC Power SuppliesWide-Range DC Input Flyback/Boost Industrial Power Supplies

The MAX17498A/MAX17498B/MAX17498C devices are current-mode fixed-frequency flyback/boost converters with a minimum number of external components. They contain all the control circuitry required to design wide input voltage isolated and nonisolated power supplies. The MAX17498A has its rising/falling undervoltage lockout (UVLO) thresholds optimized for universal offline (85V AC to 265V AC) applications, while the MAX17498B/MAX17498C support UVLO thresholds suitable to low-voltage DC-DC applications.The switching frequency of the MAX17498A/MAX17498C is 250kHz, while that of the MAX17498B is 500kHz. These frequencies allow the use of tiny magnetic and filter components, resulting in compact, cost-effective power supplies. An EN/UVLO input allows the user to start the power supply precisely at the desired input voltage, while also functioning as an on/off pin. The OVI pin enables implementation of an input overvoltage-protection scheme that ensures that the converter shuts down when the DC input voltage exceeds the desired maximum value.The devices incorporate a flexible error amplifier and an accurate reference voltage (REF) to enable the end user to regulate both positive and negative outputs. Programmable current limit allows proper sizing and protection of the primary switching FET. The devices support a maximum duty cycle greater than 92% and provide programmable slope compensation to allow optimization of control loop performance. The devices provide an open-drain PGOOD pin that serves as a power-good indicator and enters the high-impedance state to indicate that the flyback/boost converter is in regulation. An SS pin allows programmable soft-start time for the flyback/boost converter. Hiccup-mode overcurrent protection and thermal shutdown are provided to minimize dissipation under overcurrent and overtemperature fault conditions. The devices are available in a space-saving, 16-pin (3mm x 3mm) TQFN package with 0.5mm lead spacing.ApplicationsFront-End AC/DC Power Supplies for Industrial Applications (Isolated and Nonisolated)Telecom Power SuppliesWide Input Range DC Input Flyback/Boost Industrial Power Supplies

The MAX17498A/MAX17498B/MAX17498C devices are current-mode fixed-frequency flyback/boost converters with a minimum number of external components. They contain all the control circuitry required to design wide input voltage isolated and nonisolated power supplies. The MAX17498A has its rising/falling undervoltage lockout (UVLO) thresholds optimized for universal offline (85V AC to 265V AC) applications, while the MAX17498B/MAX17498C support UVLO thresholds suitable to low-voltage DC-DC applications.The switching frequency of the MAX17498A/MAX17498C is 250kHz, while that of the MAX17498B is 500kHz. These frequencies allow the use of tiny magnetic and filter components, resulting in compact, cost-effective power supplies. An EN/UVLO input allows the user to start the power supply precisely at the desired input voltage, while also functioning as an on/off pin. The OVI pin enables implementation of an input overvoltage-protection scheme that ensures that the converter shuts down when the DC input voltage exceeds the desired maximum value.The devices incorporate a flexible error amplifier and an accurate reference voltage (REF) to enable the end user to regulate both positive and negative outputs. Programmable current limit allows proper sizing and protection of the primary switching FET. The devices support a maximum duty cycle greater than 92% and provide programmable slope compensation to allow optimization of control loop performance. The devices provide an open-drain PGOOD pin that serves as a power-good indicator and enters the high-impedance state to indicate that the flyback/boost converter is in regulation. An SS pin allows programmable soft-start time for the flyback/boost converter. Hiccup-mode overcurrent protection and thermal shutdown are provided to minimize dissipation under overcurrent and overtemperature fault conditions. The devices are available in a space-saving, 16-pin (3mm x 3mm) TQFN package with 0.5mm lead spacing.ApplicationsFront-End AC/DC Power Supplies for Industrial Applications (Isolated and Nonisolated)Telecom Power SuppliesWide Input Range DC Input Flyback/Boost Industrial Power Supplies

The MAX17499/MAX17500 current-mode PWM controllers contain all the control circuitry required for the design of wide-input-voltage isolated and nonisolated power supplies. The MAX17499 is well suited for low input voltage (9.5V DC to 24V DC) power supplies. The MAX17500 is well suited for universal input (rectified 85V AC to 265V AC) or telecom (-36V DC to -72V DC) power supplies.The ICs contain an internal error amplifier that regulates the tertiary winding output voltage that is used in primary-side-regulated isolated power supplies. Primary-side regulation eliminates the need for an optocoupler. An input undervoltage lockout (UVLO) is provided for programming the input-supply start voltage and to ensure proper operation during brownout conditions. An open-drain UVLO flag output, with 210μs internal delay, allows the sequencing of a secondary-side controller. The input-supply start voltage is externally programmable with a voltage-divider. A UVLO/EN input is used to shut down the devices. Internal digital soft-start eliminates output voltage overshoot.The MAX17500 has an internal bootstrap UVLO with large hysteresis that requires a minimum 23.6V for startup. The MAX17499 does not have the internal bootstrap UVLO and can be biased directly from a minimum voltage of 9.5V.The switching frequency for the ICs is programmable with an external resistor. The MAX17499A/MAX17500A provide a 50% maximum duty-cycle limit, while the MAX17499B/MAX17500B provide a 75% maximum duty-cycle limit. These devices are available in 10-pin µMAX® packages and are rated for operation over the -40°C to +125°C temperature range.Applications1/2, 1/4, and 1/8 Brick Power Modules12V Boost and SEPIC RegulatorsHigh-Efficiency, Isolated Telecom Power SuppliesIndustrial Power ConversionIsolated and Nonisolated High-Brightness LEDIsolated Keep-Alive Power SuppliesNetworking/ServersPower Supplies