A new power supply tracking and sequencing controller can be used with modules or power supplies with or without access to feedback pins.
Linear Technology has introduced the LTC2926, a power supply tracking and sequencing controller, designed for use with modules or power supplies with or without access to feedback pins. The IC enables a variety of power up and power down profiles and supports up to three power modules: two ’slave’ supplies that track a ‘master’ signal. Tracking of up to two DC/ DC modules is achieved with N-channel MOSFETs in series with the power path, and for IC based convertors by injecting currents into their feedback nodes, without affecting their stability or the transient response.

In addition to the MOSFETs, two external resistors per channel configure the load voltages to track together, with voltage offsets, with time delays or with different ramp rates.

This variety of power up and power down profiles satisfies the requirements of digital logic circuits, such as FPGAs, PLDs, DSPs and microprocessors, making the LTC2926 ideal for such applications.

The LTC2926 features two integrated remote sense switches that automatically compensate for the voltage drop across the MOSFETs.

For applications that require more than two remote sense switches, an additional gate drive can be used to control an external remote sense MOSFET.

A power good timer sets the time allowed for a power supply to turn on after it has been enabled and will assert a fault should a supply fail to enter regulation within the allotted time interval.

The status output asserts after tracking and sequencing have completed.

Specified over the commercial and industrial temperature ranges and available from stock, the LTC2926 is offered in 20-lead SSOP and 4 x 5mm QFN packages.

Pricing begins at $3.50 each for 1000-piece quantities.

A new power supply tracking and sequencing controller can be used with modules or power supplies with or without access to feedback pins.
Linear Technology has introduced the LTC2926, a power supply tracking and sequencing controller, designed for use with modules or power supplies with or without access to feedback pins. The IC enables a variety of power up and power down profiles and supports up to three power modules: two ’slave’ supplies that track a ‘master’ signal. Tracking of up to two DC/ DC modules is achieved with N-channel MOSFETs in series with the power path, and for IC based convertors by injecting currents into their feedback nodes, without affecting their stability or the transient response.

In addition to the MOSFETs, two external resistors per channel configure the load voltages to track together, with voltage offsets, with time delays or with different ramp rates.

This variety of power up and power down profiles satisfies the requirements of digital logic circuits, such as FPGAs, PLDs, DSPs and microprocessors, making the LTC2926 ideal for such applications.

The LTC2926 features two integrated remote sense switches that automatically compensate for the voltage drop across the MOSFETs.

For applications that require more than two remote sense switches, an additional gate drive can be used to control an external remote sense MOSFET.

A power good timer sets the time allowed for a power supply to turn on after it has been enabled and will assert a fault should a supply fail to enter regulation within the allotted time interval.

The status output asserts after tracking and sequencing have completed.

Specified over the commercial and industrial temperature ranges and available from stock, the LTC2926 is offered in 20-lead SSOP and 4 x 5mm QFN packages.

Pricing begins at $3.50 each for 1000-piece quantities.

Intersil’s ISL6306/07 family addresses all VR11 CPU power requirements in desktop, server and embedded systems.
Intersil’s ISL6306/07 family addresses all VR11 CPU power requirements in desktop, server and embedded systems. The PWM (pulsewidth modulation) controllers are the industry’s first with integrated loadline and overcurrent protection (OCP) temperature compensation, enabling the designer to maintain the same current limit threshold over temperature without any increase in external components. Additionally, Intersil is sampling the ISL6326/27 VR11 PWM controllers that are drop-in enhancements to the fully released ISL6306/07 family.

Due to a proprietary, dual-edge PWM architecture that is pin-compatible with the ISL6306/07 these enable significant bulk output capacitor reduction for further system cost reductions.

The ISL6326/27 enables the highest performance/price ratio VR11 CPU core regulator.

The ISL6306/07 family and Intersil FET drivers provide the control and switching functions for VR11 CPU core multiphase buck DC/DC convertors on desktop, workstation, server, and industrial PC motherboards, also VRMs, point-of-load (POL) applications and DC/DC convertors.

The devices feature two- to six-phase operation for flexible voltage regulator design.

The VR11 PWM controllers have the industry’s highest accuracy.

The ISL6306, ISL6307 family controls VR11 microprocessor core voltage regulation by driving up to six synchronous-rectified buck channels in parallel.

The ISL6306 is optimised for desktop and embedded systems, whereas the ISL6307 family is optimised for servers and voltage regulator modules (VRMs).

The multiphase buck convertor architecture uses interleaved timing to multiply channel ripple frequency and reduce input and output ripple currents.

Lower ripple results in fewer components, lower component cost, reduced power dissipation, and smaller implementation area.

Microprocessor loads can generate load transients with extremely fast edge rates.

This family features a high bandwidth control loop and ripple frequencies up to 4MHz to provide optimal response to transients.

Today’s microprocessors require a tightly regulated output voltage position versus load current (droop).

The ISL6306/07 family senses current using patented techniques to measure the voltage across the on-resistance of the lower MOSFETs during their conduction intervals, and DCR (direct current resistance) of the output inductor when current flows through the inductor.

Current sensing provides the needed signals for precision droop, channel-current balancing, and overcurrent protection.

A programmable internal temperature compensation function is implemented to effectively compensate for the temperature coefficient of the current sense element.

A unity gain, differential amplifier is provided for remote voltage sensing, and any potential difference between remote and local grounds can be completely eliminated using the remote sense amplifier.

Eliminating ground differences improves voltage regulation and protection accuracy.

The ISL6326/27 are drop-in enhancements to the ISL6306 and the ISL6307, respectively.

The ISL6306 is available now in a 40-lead QFN package, and the ISL6307, ISL6307A, and the ISL6307B are available in a 48-lead QFN package.

The ISL6326 and ISL6327 are sampling now.

Two new DC/DC convertor ICs are optimised for extremely fast transient response in portable systems powered by single-cell lithium-ion/polymer batteries.
Optimised for extremely fast transient response, two DC/DC convertors from Advanced Analogic Technologies (AnalogicTech) are aimed at portable systems powered by single-cell lithium-ion/polymer batteries. The power supply supporting a GSM phone baseband chipset must almost instantaneously ramp from a few milliamps to full load, so an extremely fast transient response as provided by these convertors is critical. The AAT1146 and AAT2512 step-down convertors are ideally suited for GSM phone applications and allow design engineers to easily meet these stringent requirements, while keeping the convertor output in regulation.

AnalogicTech’s AAT1146 step-down convertor supports an input voltage range of 2.7 to 5.5V and output levels as low as 0.6V.

The device delivers up to 400mA of load current and maintains a no-load quiescent current of just 27uA.

The AAT2512 is a dual-channel synchronous buck convertor operating over the same 2.7V to 5.5V input range.

Each regulator features independent input and enable pins.

Each channel delivers 400mA of load current, and the device supports quiescent current levels of 27uA for light load conditions.

Both the AAT1146 and the AAT2512 are available in fixed or programmable versions with efficiency as high as 98%.

The devices use a high, 1.4MHz typical switching frequency to minimise the size of external components and keep switching losses low.

They feature internal soft-start to eliminate output voltage overshoot, and integrated overtemperature and current limit protection.

The two devices also add 100% duty cycle low-dropout operation.

The AAT1146 and AAT2512 are rated across the -40 to +85C temperature range.

The AAT1146 is available in a Pb-free compact 2.0 x 2.1mm SC70JW-8 package and the AAT2512 is offered in a Pb-free TDFN33-12 package.

A tiny fully integrated stand-alone linear battery charger replenishes single coin cell Li-ion batteries up to 250mA without overheating the device or surrounding components.
A tiny fully integrated stand-alone linear battery charger replenishes single coin cell Li-ion batteries up to 250mA without overheating the device or surrounding components.
Linear Technology has introduced the LTC4065L, a tiny fully integrated stand-alone linear battery charger that charges single coin cell Li-ion batteries up to 250mA without overheating the device or surrounding components. This full-featured IC offers a 4.2V +/-0.5% accurate float voltage, 5% charge current accuracy, timer termination and C/10 detection and is housed in a miniature 2 x 2mm DFN package. A complete solution requires only two discrete components (input capacitor and a charge current program resistor) and fits into a 2.5 x 2.7 x 0.75mm form factor.

Its small size and ability to regulate low charge currents make it well suited for applications in small capacity rechargeable lithium-battery-powered portable devices such as MP3 players, wireless headsets and Bluetooth-enabled devices.

The LTC4065L requires no external MOSFET, sense resistor or blocking diode.

A patented thermal regulation scheme prevents the junction temperature of the IC from exceeding 115C by reducing charge current during high power or high ambient temperature operation.

Other features of the LTC4065L include a charge current monitor output for charge termination, recharge, trickle charging and charge status indication.

Charge current is adjustable with a standard off-the-shelf resistor.

The device is designed to work with supplies up to 5.5V, including those within USB specifications and from 5V wall adapters.

During shutdown, the supply current is only 20uA and battery drain current is less than 1uA, extending battery run time.

The LTC4065L is rated for operation from -40 to 85C.

Pricing starts at $1.10 each in 1000-piece quantities.

ON Semiconductor has announced that total revenues in the fourth quarter of 2005 were $341.8 million, an increase of approximately 9% from the third quarter of 2005.
ON Semiconductor has announced that total revenues in the fourth quarter of 2005 were $341.8 million, an increase of approximately 9% from the third quarter of 2005. During the fourth quarter of 2005, the company reported net income of $43.8 million. Fully diluted earnings per share for the fourth quarter of 2005 were $0.07 per share, which included a deemed dividend charge of approximately $0.06 per share, associated with a premium, in the form of inducement shares, for the conversion of the Series A Cumulative Preferred Stock into common stock.

During the third quarter of 2005, the company reported net income of $23.5 million, or $0.06 per share on a fully diluted basis.

On a mix-adjusted basis, average selling prices in the fourth quarter of 2005 were down approximately 2% from the third quarter of 2005.

The company’s gross margin in the fourth quarter was 35.0%, an increase of approximately 180 basis points as compared with the third quarter of 2005.

EBITDA for the fourth quarter of 2005 was $76.8 million and included a $0.8 million restructuring, asset impairments and other benefit.

EBITDA for the third quarter of 2005 was $65.4 million and included $0.2 million in restructuring, asset impairments and other charges.

The $0.8 million in restructuring, asset impairments and other benefit for the fourth quarter of 2005 was primarily related to reversals of previously accrued costs associated with the closure of our East Greenwich manufacturing facility.

Although total revenues for 2005 of $1.261 billion were approximately flat compared with $1.267 billion of revenues for 2004, fourth quarter 2005 revenues of $341.8 million were up approximately 11% compared with fourth quarter 2004 revenues of $306.8 million.

During 2005 the company reported net income of $100.6 million that included $3.3 million in restructuring, asset impairments and other charges.

During 2004 the company reported a net loss of $123.7 million that included a loss on debt prepayment of $159.7 million and restructuring, asset impairments and other charges of $19.6 million.

The company’s gross margin increased by approximately 80 basis points to 33.2% in 2005 from 32.4% in 2004.

‘2005 was a significant year for the company’, said Keith Jackson, ON Semiconductor President and CEO.

‘We exited the year with the highest gross margin and the first year of profitability since 2000′.

‘We also shipped record units during the fourth quarter at an annualised run rate of approximately 30 billion units’.

‘We look to continue to fuel our growth with new product designs and wins in the computing, consumer and wireless end-markets and are excited about our prospects for the upcoming year’.

‘Based on booking trends, backlog levels and estimated turns levels, we anticipate that total revenues will be approximately $330 million in the first quarter of 2006 as compared with revenues of $302.4 million in the first quarter of 2005 and revenues of $341.8 million in the fourth quarter of 2005′, Jackson said.

‘Backlog levels at the beginning of the first quarter were up from backlog levels at the beginning of the fourth quarter of 2005, and represented over 90% of our anticipated first quarter 2006 revenues’.

‘We expect that average selling prices will be down approximately 1% for the first quarter of 2006′.

‘We also expect cost reductions to offset the decline in average selling prices and that gross margins will be flat at approximately 35% in the first quarter of 2006′.

‘Beginning in the first quarter of 2006, we are required to expense stock-based compensation’.

‘This is in accordance with the Statement of Financial Accounting Standards No 123 Share Based Payment’.

‘We currently expect this expense to be approximately $2 million in the first quarter of 2006′.

A new family of current-mode adjustable-frequency step-up convertors with internal 2A/40V switches can be adapted in a
Semtech Corp has released the SC4501, SC4502 and SC4502H, a family of current-mode, adjustable frequency step-up (boost) convertors with internal 2A/40V switches. Each convertor can be adapted in a variety of topologies such as boost, sepic and flyback for generating high output voltage from multicell alkaline, NiCd, NiMH or single-cell Li-ion batteries. The boost convertors operate from input voltages as low as 1.4V to generate outputs to 40V at efficiencies over 90%.

Switching frequency can be programmed using a single resistor to select the desired value between 250kHz and 2MHz.

A high frequency of operation enables the system designer to minimise external component size and avoid interference with noise sensitive frequency bands in the system.

A small inductor and ceramic capacitors keep the total solution footprint compact while minimising total solution cost.

The SC4501, with a low-saturation-voltage (220mV) switch, delivers up to 2A at 32V.

The SC4502 and SC4502H feature 210 and 250mV saturation-voltage switches, respectively, to supply up to 1.4A at 32V for the SC4502 and 1.4A at 40V for the SC4502H.

The boost convertor family is ideal for driving up to 10 white LEDs in series configuration for backlighting in cellphones, PDAs and automotive displays.

The high current internal switches also make them well suited for generating bias voltages in LCD panels and for system voltages in battery operated systems such as portable DVDs, digital video cameras, portable medical equipment and many other consumer portables.

The SC4502 and SC4502H include most of the features of the SC4501 and are further optimised for high efficiencies at light loads.

Equipped with a smaller 1.4A switch, they have a low shutdown supply current of 10uA.

In battery-operated appliances where battery conservation is crucial, the SC4502 and SC4502H are highly attractive choices.

The device family includes additional features such as programmable soft start and programmable undervoltage lockout (UVLO) which help eliminate inrush currents during startup and protect the system from line voltage transients, thereby ensuring reliable system performance.

‘Semtech has traditionally dominated the white LED driver market with its charge pump convertor products’, says Ven Shan, VP of Marketing for Semtech’s Power Management Products.

‘The SC4501, SC4502 and SC4502H are inductor-based convertors that complement and extend Semtech’s portfolio of white LED drivers’.

‘They provide performance and efficiency advantages for driving up to 10 white LEDs in series-connected LCD backlight applications, yet are flexible enough to address a much broader range of applications’.

The SC4501 is available in a 3 x 3mm, 10-pin MLPD and in an 8-pin MSOP package.

The SC4502 and SC4502H are offered in the 3 x 3mm 10-pin MLPD package only.

Both packages incorporate a special thermal design for high-power applications.

The lead-free design of the devices meets worldwide environmental and regulatory requirements including the European Union’s RoHS Directive.

All products are available immediately in production quantities.

The SC4501 is priced at $0.89 each in 1000-piece lots with ordering code SC4501MLTRT (MLPD package) and SC4501MSETRT (MSOP package).

The SC4502 is priced at $1.05 each in 1000-piece lots with ordering code SC4502MLTRT (MLPD package).

And, the SC4502H is priced at $1.05 each in 1000-piece lots using ordering code SC4502HMLTRT (MLPD package).

The LTC3412A is a high-efficiency 4MHz synchronous buck regulator based on a constant-frequency current-mode architecture.
Linear Technology has announced the LTC3412A, a high-efficiency 4MHz synchronous buck regulator based on a constant-frequency current-mode architecture. It can deliver up to 3A of continuous output current at voltages as low as 0.8V from a 4 x 4mm QFN (or a thermally enhanced TSSOP-16) package. It operates from an input voltage of 2.25 to 5.5V, making it ideal for both single cell Li-ion, or NiMH applications, as well as more general purpose fixed rail systems.

Its 4MHz switching frequency allows the use of tiny low cost capacitors and inductors with less than 1.5mm profile.

High frequency operation also keeps switching noise out of critical wireless and xDSL frequency ranges, making it ideal for xDSL modems, cellular basestations and automotive applications.

The LTC3412A uses internal switches with on-resistances of only 0.065 and 0.077ohm to deliver efficiencies as high as 95%.

It also utilises low dropout 100% duty cycle operation to allow output voltages up to the input.

No load quiescent current is only 64uA, and less than1uA in shutdown, making it ideal for applications such as automotive power systems that require ultra-low supply currents.

For optimum efficiency at light loads, the LTC3412A uses selectable burst mode operation to reduce gate charge losses.

The current at which the Burst Mode operation initiates is user programmable, enabling the designer to optimise light load efficiency.

If the application is noise sensitive, the sync/mode pin can also be configured to provide forced continuous operation to reduce noise and RF interference.

Additional features include a power good voltage monitor, external synchronisation capability, and thermal protection.

The LTC3412A is ideal, for applications requiring 3A of output current, and where a small solution size and low supply current are critical.

The LTC3412A is available from stock in a QFN-16, or a 16-lead thermally enhanced TSSOP package.

Pricing starts at $4.10 each in 1000-piece quantities.

STR-CAD Design Aid software helps users to develop cost-effective switch-mode power-supply designs using the Sanken Electric STR series of switching-regulator integrated circuits.
Now available from Allegro MicroSystems Europe is STR-CAD Design Aid software: an easy-to-use design tool which allows users to develop cost-effective switch-mode power-supply designs using the STR series of switching-regulator integrated circuits from Sanken Electric - Allegro’s parent company. The free downloadable software is available for use with the STR-A6100, STR-A6200 and STR-W6700 Series of switching regulators, and allows the user to choose one of several topology options: pulsewidth modulation (PWM), quasiresonant or pulse-ratio control (PRC). Users can select from single or multiple output configurations, and the software then quickly guides the user through the process of specifying power-supply requirements with default values, automatically calculating transformer details and other component parameters.

The STR-CAD Design Aid software also provides simulated operation of the virtual design created, and allows the user to make adjustments in parameters, interactively or automatically, for further investigation.

The Sanken STR-A6100 Series are PRC topology ICs with fixed off-time and variable on-time control, and are designed for relatively low output power switch-mode power-supply designs in which output power is up to 20W at universal input or 24W at 230V AC input.

The Sanken STR-A6200 Series are relatively low output power off-line PWM topology switching regulator ICs which have a jittering function for cost reduction of EMI noise-filtering circuits.

The STR-W6700 Series includes quasiresonant topology ICs designed for switch-mode power supplies, showing lower EMI noise characteristics - especially at more than 2MHz - than conventional PWM solutions.

The STR-CAD Design Aid software is available free of charge on the Allegro MicroSystems website.

Sanken Electric semiconductor devices are available in Europe from Allegro MicroSystems Europe and via its network of distributors.

A new compact and highly integrated 1.5A synchronous step-up convertor operates with an input voltage as low as 1.8V while maintaining an overall operating efficiency greater than 90%.
Monolithic Power Systems (MPS) has released the MP1543, a new compact and highly integrated 1.5A synchronous step-up (boost) convertor that operates with an input voltage as low as 1.8V while maintaining an overall operating efficiency greater than 90%. The MP1543 features output disconnect to dramatically cut leakage current in shutdown mode and conserve battery life. Available in the compact thin SOT23-5 package, this combination of features makes the MP1543 ideally suited for battery-powered applications using a single Li-ion or two alkaline (AA, AAA) cells.

The MP1543 is a perfect device for mobile phones, handheld computers/PDAs, portable media players, cordless input devices, digital still/video cameras, and small liquid-crystal/OLED displays.

Additional features of this compact, low voltage boost convertor include thermal shutdown, soft-start, and an adjustable output voltage range of 2.5 to 6V.

This convertor also integrates 500kHz top and bottom switches supporting up to 800mA output current in a 3.6 to 5V boost application.

Pricing for the MP1543 is $1.51 in 1000 piece quantities.

Samples and an evaluation board are available now.