Maxim Integrated Products’ MAX4908/MAX4909, dual single-pole, triple-throw (SP3T) analog switches handle negative signals with a single-positive power supply. The devices feature integrated shunt resistors to ground. This feature reduces audio popping and clicking sounds by depleting the capacitive charge, which commonly builds up on the unconnected port of the switch, to ground. In addition, the device has an extremely low 0.38-Ω on-resistance, low 0.35-Ω onresistance flatness and low 0.02% total harmonic distortion. The AX4908/MAX4909 are both available in a 12- bump UCSP (1.5 mm 2 mm) and a 14-pin TDFN package (3 mm x 3 mm). Prices start at $1.20 each in 1000-unit quantities.
Charge Pump White LED Driver
Allegro MicroSystems has released the A8435, a higheffi ciency charge pump white LED driver. The device is a solution for portable electronics display applications. Using a proprietary control scheme (1x, 1.5x), this LED driver can output wellmatched LED currents for up to four channels, while maintaining the highest effi - ciency over most of the Li-ion battery lifetime.
The part accepts an input range of 2.7 V to 5.5 V and delivers up to 30 mA for each of the four regulated current sources. It can deliver a total output current of 120 mA, meeting the requirements of most Li-ion battery-powered white LED backlight applications. Outputs can also be combined for white LED fl ash/torch applications. The A8435 is available in a 0.75-mm profile, 3-mm x 3-mm MLP-16 package (A8435EES).
Linear Technology's LT3491 is a high-efficiency constant-current white LED driver. The LT3491 features an integrated Schottky diode on-chip, eliminating the external diode. A high-side LED current-sense topology enables the LED cathode to be connected directly to ground, creating a single-wire current source. The LT3491 is designed to drive up to six white LEDs from a single Li-ion cell at effi ciencies over 75%.
The LT3491 switches at 2.3 MHz, allowing the use of a tiny inductor and capacitors while keeping switching noise out of critical RF frequency bands. Its combination of high effi ciency, low noise and small “total solution” footprint make it ideal for handheld applications requiring up to six white LEDs.
The LT3491 is available from stock in an eight-lead SC70 package. Pricing starts at $1.25 each in 1000-piece quantities.
Linear Technology Milpitas, Calif.
Buck Regulator for GPUs
Intersil has introduced the ISL6263, a single-phase buck voltage regulator that powers next-generation graphics processing units (GPUs) or graphics cores used on Intel’s Santa Rosa platforms. This device reduces power consumption and enhances the performance of the GPU by dynamically changing output voltage and operation modes corresponding to the advanced GPU control protocol.
The modulator at the heart of this power system is created using Intersil’s patented Robust Ripple Regulator (R3) technology. Compared with traditional single-phase buck regulators, Intersil’s R3-based converters provide better transient response and effi ciency, and are capable of changing the voltage output when the GPU is in suspend or sleep mode.
The ISL6263 is available in a 32-lead thin QFN package. Pricing is $2.70 each in 1000- unit quantities.
Intersil Milpitas, Calif.
The DR359 Series SMT Inductor/Transformer from Datatronics features a unique dual coil design. With a low seated profi le standing only 0.315 in. above the circuit board in a square package, the DR359 Series Inductor/ Transformer is a versatile magnetic component featuring both parallel and series functionality. The DR359’s unique dual coil design allows circuit designers to take advantage of its ability to support circuit requirements for either an inductor or transformer. The DR359 Series Inductor/ Transformer features an inductance range from 0.47 mH to 1000 mH. The parallel windings feature an inductance range from 0 . 4 1 9 mH to 1 0 0 5 mH (+20%), with a DCR from 0.00195 Ω to 1.6600 Ω. The series windings inductance ranges from 1.676 mH to 4020 mH (+25%), with a DCR from 0.0078 Ω to 6.640 Ω. The DR359 measures 0.493 in. square and is priced from $0.25 each in typical production volume.
Datatronics Romoland, Calif.
APX Series Aluminum Nitride (AlN)–based components from International Manufactur ing Ser v ices (IMS) give designers the ability to upgrade power handling capability without increasing footprint size. Due to its greater thermal conductivity properties, AlN allows designers to avoid costly redesigns by packing more power into a samesized footprint.
The APX Series products are manufactured using robust, thick fi lm technology, and are suited to demanding applications. They are available in 10-Ω to 2-kΩ resistance values.
International Manufacturing Services
Powerex has introduced a family of 1700-V devices that use carrier stored trench gate bipolar transistor (CSTBT) IGBT technology. The new ASeries family, which replaces Powerex’s KA-Series in the range of 75 A to 400 A, offers compatible packaging with the 1200-V CSTBT family, to make the addition of drives for 575-V and 690-V lines an easy transition.
The A-Series reduces onstate losses by 35%, a level that is equal to third-generation 1200-V devices. The devices are available with current ratings of 75 A, 100 A, 150 A, 200 A, 300 A and 400 A at 1700 V in dual or half-bridge packaging. Pricing for the A-Series family of products in quantities of 10 ranges from $63 to $282 each.
Configurable Power Supply
The A3600 from Powerstax is a series of low-profi le 1U high, 19-in. rack-mount, configurable ac-dc power supplies. Capable of providing up to 3600-W output power, the A3600 offers users multi-output power solutions without extended lead times and high nonrecurring engineering costs.
The A3600 employs a modular construction using high-effi ciency (greater than 90%) standard products from the Powerstax range. The A3600 offers combinations of single- or multi-output, regulated dc power from a universal input mains supply of 85 Vac to 264 Vac. Input and output connection may be specifi ed at the front or rear and may be cable entry, connector or safety stud as required.
With up to 18 isolated and adjustable outputs, it is possible to individually margin, enable, parallel or stack the outputs to provide multiple power variants. Features include zero-load operation and fully floating outputs that have standard output voltage ranges from 1.5 V to 58 V, few electrolytic capacitors (all long life), local and remote adjustment, and useradjustable current limit and inhibit/enable functions.