Taiyo Yuden's NR8040T series of 8-mm × 8-mm × 4-mm wirewound power inductors is intended for dc-dc converter choke coil applications. The 13 models in the series offer a combination of low dc resistance (0.006 Ω to 0.29 Ω), high inductance (0.9 µH to 100 µH) and high current ratings (1 A to 11.8 A). The NR8040T-100M device, for example, offers rated current at 3.4 A for 10 µH in the 8-mm × 8-mm form factor. Sample pricing is $0.30 each.
LDO Linear Regulator
Micrel's MIC5301, a low dropout (LDO) linear regulator, offers a dropout of 40 mV at 150 mA, more than 75 dB PSRR and low output noise. The device is offered in a 1.6-mm × 1.6-mm 6-pin MLF package. The MIC5301 achieves excellent transient performance with the use of just one 1-µF ceramic capacitor. In addition, it features a low quiescent current and a fast turn-on time of 30 µs.
Pricing for the MIC5301 starts at $0.45 each in 1000-unit quantities.
San Jose, Calif.
Intended to be used for dc-dc converter applications, the OptiMOS 3 30-V n-channel MOSFET family improves reliability and energy efficiency by 1% to 1.3% in typical power-supply applications.
The OptiMOS 3 will be available in eight package types, with a total of more than 80 devices. These packages include the Shrink SuperSO-8 (S3O8), a 3-mm × 3-mm package, and a SuperSO-8 package, which offers a maximum RDSON of only 1.6 mΩ.
Compared to the OptiMOS 2, the OptiMOS 3 features several major improvements including on-resistance reduction by 30%; a 30% improved figure of merit, while offering similar performance in a 60% smaller package (S3O8) compared to OptiMOS 2. In an S3O8 package, the price of a 3.5-mΩ device is less than $0.70 each.
Stackpole Electronics' SMD chip resistor series is more reliable in high sulfur conditions than traditional resistors. Designated the RMCS series, the resistors are available in sizes from 0201 to 2512, in resistance values from 10 Ω to 22 MΩ in tolerances as low as 1% and TCs as low as 100 ppm. This series offers a 0-Ω jumper for each size as well.
The RMCS series has a proprietary inner termination material that greatly reduces the amount of silver present. Most standard chip resistors have a relatively high amount of silver in their inner terminations that, in the presence of a high sulfur environment, can react to form nonconductive silver sulfide.
The IRF6641TRPBF Power MOSFET from International Rectifier features DirectFET package technology paired with IR's latest 200-V HEXFET MOSFET silicon technology and achieves 95% efficiency. This device is designed for use in isolated dc-dc converter designs operating from 36 V to 75 V. At 25°C, the device provides ID = 25 A when VGS = 20 V.
With its typical 10-V RDSON of 51 mΩ and a gate charge of 34 nC, the IRF6641TRPBF is ideally suited as a synchronous rectifier MOSFET in high-frequency, high-efficiency dc-dc converters. The IRF6641TRPbF DirectFET MOSFET is priced at $1.24 each in 10,000-unit quantities.
El Segundo, Calif.
Power Management Controllers
Semtech's SC457 and SC458 power supply controllers feature digitally controlled output and fast transient performance for powering processors and graphics chips in notebook PCs. With a built-in 7-bit DAC, the output of the controllers can be programmed in 12.5-mV steps from 0.3 V up to 1.5 V. A programmable DAC slew rate minimizes transient currents and audible noise. The single-phase SC457 drives up to 30 A, while the dual-phase SC458 drives up to 60 A and switches seamlessly between single- and dual-phase operation. In lots of 1000, unit pricing is $1.94 each for the SC457 and $2.80 each for the SC458.