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Fan Speed Controller
The TDA21801 fan speed controller from Infineon Technologies is an intelligent controller that allows manufacturers of cooling fan systems to deliver the functionality of a four-wire fan using a lower-cost two-wire fan. This can reduce the bill of materials by 25%.
A typical four-wire fan solution with overtemperature protection (OTP) requires 27 components, while a two-wire fan solution using the TDA21801 requires only 13 components. The TDA21801 can adjust fan speed from 750 rpm to 4000 rpm, which makes it ideal for applications requiring low fan speed to reduce noise levels.
The TDA21801 is available in a RoHS-compliant SO-8 package at a price of $0.70 in quantities of 50,000.
Intersil has expanded its power management portfolio with the introduction of a synchronous stepdown controller with up to 95% efficiency. The ISL88550A integrates a synchronous buck pulse-width modulation (PWM) controller, a sourcing and sinking low-dropout (LDO) regulator and a 10-mA reference output buffer. The constant-on-time PWM controller generates voltage for double data rate memory, the LDO regulator generates termination voltage supply and the reference output buffer generates termination voltage reference.
It features a 1.8-V/2.5-V fixed or 0.7-V to 3.5-V adjustable output and a 2-V to 25-V input voltage range. Switching frequencies available are 200 kHz, 300 kHz, 450 kHz and 600 kHz, and the step response of the output is 100 ns. With the combined features, the ISL88550A provides a complete solution for double data rate I and II memory power supplies.
The ISL88550A is available now in a 28-pin 5-mm × 5-mm thin QFN package and is priced at $2.85 in 1000-unit quantities.
Power Supply Kits
IXYS and ASIC Advantage have collaborated to bring to market new design kits for low and medium power supply requirements. Featured design kits include a highly flexible low EMI platform for isolated and nonisolated ac-to-dc switch-mode power supplies, featuring line and load protections, very high efficiency and very low standby power. The first targeted design kit, made available in the fourth quarter of 2005, is the ASIC Advantage IPS-DK18/IXYS PN EVPS001 targeted for off-line applications below 10 W.
The ASIC Advantage line of IN-PLUG Controllers features flyback, feedback, PFC, push-pull and LED controllers. These design kits feature IXYS's new rugged PolarHV Power MOSFETs, as well as the company's line of low-conduction-loss Schottky diodes and ultrafast soft-switching HiPerFRED diodes.
Santa Clara, Calif.
International Rectifier (IR) has introduced the IPS10xx family of low-side intelligent power switches (IPS). The devices are qualified to Q100, making them ideal for harsh automotive environments. The new IPS line includes the IPS1011R, a 13-mΩ device in a D-PAK that enables circuit designers to pack more current-handling capability into existing board layouts.
In addition, the IPS devices include protection and a logic-level input and diagnostic information pin to monitor or detect faults during operation. Signals from this pin can be fed back to a microcontroller to trigger a specific sequence or restart strategy following a fault condition.
Pricing for the IPS1011R starts at $1.84 each in 10,000-unit quantities.
El Segundo, Calif.
Battery Charger IC
Advanced Analogic Technologies has announced the AAT3686, a Li-ion/polymer battery charger IC designed to operate off both USB and ac adapter inputs. This new dual-path charger features both an innovative digital thermal loop and a charge-reduction loop that allows users to charge the battery with available current from the USB port while keeping the port voltage regulated.
The AAT3686 maximizes charging current by measuring internal circuit die temperature and reducing fast-charge current when the circuit die temperature exceeds preset thresholds. For rapid charging, the AAT3686 supports programmable adapter charge current rates up to 1.5 A. USB charge rates can be programmed up to a maximum current level of 500 mA. The AAT3686 can also report up to 22 different charging status states to a microcontroller via a serial interface output.
The AAT3686 is immediately available in a lead-free, thermally enhanced, 16-pin 4-mm × 4-mm TDFN package. The device sells for $1.64 in 1000-piece quantities.
Power Drawer Connectors
Anderson Power Products (APP) has added the Power Drawer series of connectors to its connector range. The family features blind mating connectors for 35-A or 75-A applications. These versatile Power Drawer connectors are used on “N + 1” power supply and rectifier systems ideal for server, telecommunications and network applications. APP's durable connectors are UL recognized and are able to mate with competitive products, offering the designer and user further development and sourcing options.
APP's 35-A Power Drawer connectors can be configured with up to eight #12 AWG power contacts, eight #16 AWG power contacts or a combination of four #16 AWG power contacts, four #12 AWG power contacts and 21 #20 AWG signal contacts. APP's 75-A Power Drawer connectors can be configured with up to four #8 AWG power contacts, nine #12 AWG power contacts and 24 #20 AWG signal contacts. Float-mount and pc board-mount versions are available for both connectors.
Anderson Power Products
FCI further increases the design flexibility of its AirMax VS system with the introduction of a new right-angle power receptacle. Designed to mate with existing right-angle header power connectors, the power receptacle enables power connections between co-planar circuit boards and complements the AirMax co-planar product range that already includes signal connectors and guidance modules.
AirMax VS power connectors are designed to maximize the airflow passages in the insulating connector bodies, contributing to the modules' higher current-carrying capacity.
Two available mating lengths for power receptacle contacts provide capability for sequential mating of power and signal contacts. The protected back of the connector meets the UL 60950 compliance for finger probe protection, and the AirMax VS power modules are also RoHS-compliant. The power connectors employ an “eye of the needle” (EON)-compliant tail for press-fit pc board termination. Volume pricing for the AirMax VS co-planar power receptacle is $2 per connector. Co-planar guides are also available.
Linear Regulator Supply
Maxim Integrated Products has introduced the MAX8761, a complete linear-regulator power supply solution for thin-film transistor (TFT) liquid-crystal-display (LCD) panels used in LCD monitors and LCD TVs. The device includes a high-performance linear regulator, a positive and a negative charge-pump regulator, built-in power-up sequence control and a high-current operational amplifier. Additionally, the MAX8761 provides logic-controlled high-voltage switches to control the positive charge-pump output.
The MAX8761's linear regulator directly steps down the input voltage to generate the supply voltage for the source-driver ICs. Output accuracy is 1.6% with a fast transient response. The two built-in charge-pump regulators generate the TFT gate-on and gate-off supplies. The high-current operational amplifier is typically used to drive the LCD backplane (VCOM) and features high output current (150 mA), fast slew rate (12 V/µs) and wide bandwidth (12 MHz).
The MAX8761 is available in a 4-mm × 4-mm, 0.8-mm, 24-pin thin QFN package. Prices start at $3.62 for 1000-unit quantities.
Maxim Integrated Products
Charger IC Family
Power Integrations has introduced the LinkSwitch-XT, targeted for applications where tight regulation of output voltage and current are key design priorities. The new ICs support universal-input (85 Vac to 265 Vac) chargers and adapters with output levels of up to 4 W, and may be used in open-frame applications up to 9 W (230 Vac). This charger features EcoSmart technology, ideal for use in chargers and adapters designed to comply with energy-efficiency standards for external power supplies.
The LinkSwitch-XT features a 700-V power MOSFET together with control circuitry on a single silicon die. It is available in lead-free, plastic through-hole DIP-8 and surface-mountable SMD-8 packages. Pricing in 1000-piece quantities for the LNK362PN, a 2.6-W part in a DIP-8 package, is $0.53 each. The LNK364PN, a 6-W part, is priced at $0.55 each.
San Jose, Calif.
From Renesas Technology, the M62298FP dc-dc converter incorporates a total of seven stepup converter and stepdown converter channels for digital still cameras (DSCs). Six of the M62298FP's seven channels have one or two built-in MOSFETs. Achieving 85% power conversion efficiency from a Li-ion battery or similar power source, the M62298FP also helps to extend battery life.
The input voltage range of the M62298FP is 2.5 V to 6 V, making it suitable for use with devices capable of operating on a 1-cell Li-ion battery. The main features of the M62298FP are designed to reduce the size of DSCs and extend battery life. The package used is a leadless 52-pin QFN package (0.4-mm pitch) 7 mm × 7 mm in size.
Selectable Polarity Dual Supervisor
Linear Technology introduces the LTC2909, a dual low-voltage adjustable input supervisor intended for a variety of system monitoring applications. The device can monitor two supplies — positive, negative or both — for undervoltage, overvoltage or one of each. It also may monitor a single supply (positive or negative) for undervoltage and overvoltage simultaneously.
The low-voltage threshold of 0.5 V comes with an accuracy of ±1.5%, ensuring reliable reset operation without false triggering. A precision undervoltage lockout allows VCC to be used as an accurate third fixed 10% undervoltage supply monitor. The common reset output delay can be configured to use a preset 200-ms timeout, adjusted by an external capacitor or disabled. In addition to quiescent current of 50 µA, the onboard featured 6.5-V shunt regulator permits operation from a high-voltage supply.
The LTC2909 IC is offered in 8-pin SOT-23 and 3-mm × 2-mm DFN packages and is specified over the commercial and industrial temperature ranges. Pricing begins at $1.55 each for 1000-piece quantities.
The OP520 and OP521 Series devices from OPTEK Technology, a TT Electronics company, are silicon NPN phototransistors designed to detect 880-nm wavelength infrared light. Both devices are packaged in a 1206 chip with a flat molded lens; the OP520 features an opaque lens to shield it from ambient light, while the OP521 lens is water clear, giving it a wider response range.
Electrical performance of the OP520/521 Series is characterized at a collector-emitter voltage of 30 V, emitter-collector voltage of 5 V, collector current of 20 mA and power dissipation of 75 mW at 25°C. The phototransistors are designed to be mechanically and spectrally matched to OPTEK's OP250 Series surface-mount infrared LEDs.
Typical pricing for the OP520/OP521 Series phototransistors starts at $0.20 each in quantities of 1000 pieces.