- Motor Drive ICs
TARGETED AT the portable and instrumentation markets, Allegro's A3908 is a low-voltage bidirectional dc motor driver with a typical input voltage range of 3 V to 5.5 V and output currents up to 500 mA. The unique full-bridge output incorporates source side linear operation to allow a constant voltage supply across the motor coil. This regulated output minimizes motor voltage change due to I × RDS(ON) variation and battery voltage tolerance.
Two logic inputs are provided to control the motor direction of rotation, brake and standby (< 500-nA supply current) modes and to allow optional PWM of the sink drivers. Internal protection circuitry includes thermal shut down, undervoltage lockout, and crossover (shoot through) protection.
Priced at $0.45 in quantities of 1,000, the A3908 is supplied in a Pb-free 2-mm × 2-mm × 0.575-mm nominal, 8-lead DFN package, with exposed thermal pad (package suffix “EE”).
Allegro Microsystems; Worcester, Mass.
- Hot-Swap SMPS ICs
Texas Instruments' TPS2420 family of hot-swap managers helps protect against overcurrents for voltage rails between 3 V and 20 V and an operating current of up to 5 A. The TPS2420 comes in a 16-pin QFN package while the TPS2421-1 and TPS2421-2 are available in 8-pin SOIC packages and offer more than twice the current throughput of existing hot-swap managers with integrated FETs in the same voltage range. The TPS2420 family supports applications such as disk drive arrays, network clients, industrial monitoring devices and communications systems.
Requiring up to 70% fewer external components than competitive products to implement a complete solution, each device can operate across the entire operating voltage range with only the timing capacitor and resistor-set current thresholds The TPS2420 is available now. The TPS2421-1 and TPS2421-2 will be available in second quarter 2009.
Texas Instruments; Dallas
VISHAY INTERTECHNOLOGY'S VSMP0603 ultra-high-precision Bulk Metal Z-Foil (BMZF) wraparound surface-mount resistor features an extended power rating to 0.1 W and higher resistance values to 5 kΩ. The device is the industry's first in the 0603 chip size to offer a military-grade absolute TCR of ±0.2 ppm/°C from -55°C to +125°C, +25°C ref., a tolerance of ±0.01%, and an almost immeasurable 1-ns rise time, effectively without ringing. While typical 0603 resistors offer a load-life stability of ±0.1% through a 1,000-hr workload, this device offers an improved load-life stability of ±0.005% (50 ppm) at +70°C for 2,000 hr at rated power.
The resistor also features a full wraparound termination that ensures safe handling during the manufacturing process, as well as providing stability during multiple thermal cycling. Wraparound terminations render the VSMP0603 solderable in various board positions, and its 0.06-in. × 0.03-in. footprint is currently the smallest available in Foil-based technology.
Prototype samples and production orders of the VSMP0603 resistor are available now, with lead times from six weeks. Pricing starts at $4.
Vishay Intertechnology; Malvern, Pa.
- DC-DC Converter
Linear Technology's LT3571 is a fixed frequency, current-mode step-up dc-dc converter with an integrated high-side avalanche photodiode (APD) current monitor. The device can deliver output voltages up to 75 V from inputs ranging from 2.7 V to 20 V, making it suitable for a wide range of fiber-optic applications.
The LT3571 features a high-side fixed voltage drop APD current monitor, providing better than 10% relative accuracy over the -40°C to 125°C temperature range. The fixed 5-V (±5%) drop across the current monitor is unique to the LT3571 and enables higher data bandwidths in many fiber-optic applications. The power switch, Schottky diode and APD current monitor are integrated into a single IC that is packaged in a 3-mm × 3-mm QFN. Other features include soft-start, internal compensation and thermal shutdown.
The LT3571's internal 75-V, 350-mA switch offers output voltages as high as 75 V. Its switching frequency can be programmed between 250 kHz and 2 MHz, enabling users to optimize efficiency while minimizing the size of the external components. Constant frequency architecture is used to keep output ripple below 500-u VPK-PK, which is critical in most APD applications.
The LT3571EUD is priced at $2.45 each in 1,000-piece quantities. An industrial-grade version, the LT3571IUD, is priced at $2.72 each in 1,000-piece quantities.
Linear Technology; Milpitas, Calif.
- Switcher ICs
POWER INTEGRATIONS has expanded its LinkSwitch-II product family to include the LNK632DG. Designed for applications with up to 3.1 W of output, the device enables manufacturers to meet worldwide energy-efficiency and no-load regulations for low-power chargers and adapters, such as ENERGY STAR EPS v2.0. Additionally, the LNK632DG enables the industry's lowest BOM cost for cellphone chargers designed to achieve a 5-star efficiency rating with no-load power consumption of 30 mW or less. The product also cuts the cost of USB chargers and LED light bulb designs by eliminating the need for clamping circuitry and therefore reducing component count.
The LNK632DG's protection and safety features include auto-restart, output short-circuit protection and hysteretic thermal shutdown. IEC 60950-1 HV creepage requirements are met between the drain pin and other pins, and all single-point failures are safely handled.
Housed in a 8-pin surface-mount package, LNK632DG devices are available from $0.42 each in 100,000-unit quantities.
Power Integrations; San Jose, Calif.