Electronic Design

Infineon, National Semi Claim Firsts On Regulator And Op-Amp Designs

Nearly every new design tries to add functionality while using less power. Recent products from Infineon Technologies, National Semiconductor, Ricoh Europe BV, and Dialog Semiconductor all seek to provide that efficiency. In fact, Infineon and NI claim that their new devices represent benchmarks in power technology.

Single-Chip Regulator

According to Infineon Technologies, it has designed the world’s first single-chip linear voltage regulator with integrated diagnosis and car radio system protection functions. Its TLF 4277 low-dropout (LDO) voltage regulator has adjustable output voltage to support most standard active antennas, including FM/AM, DAB (Digital Audio Broadcast), and the XM and Sirius satellite radio bands. With its integrated current monitor and adjustable current limitation, it should reduce the number of discrete components for active antenna applications by approximately 50%, Infineon says.

More than 95% of all cars now produced worldwide feature active antennas for radio program reception. Active antennas are small enough to fit into the windscreen, front bumper, or stub antenna on the car’s roof. According to current market research, about 52 million to 55 million cars are expected to be produced globally in 2009 despite the current downturn in sales. On average, cars are equipped with two active antennas and two active antenna voltage regulators.

The monitor function of the TLF 4277 allows the detection of failures and simple integration of a failure analysis function in an infotainment system. The AEC-Q100 qualified device is protected against failure situations, such as short circuit of the output against ground or battery voltage, overtemperature, and overcurrent. Pricing for 1000-unit quantities is $1.11 each.

Nanopower Op Amp

Also, National Semiconductor says its LPV521 nanopower operational amplifier provides the industry’s lowest power consumption at 552 nW, with guaranteed operation down to 1.6 V. Its supply voltage ranges from 1.6 to 5.5 V with a maximum supply current of 0.4 µA, and its power-to-performance ratio is 65 µA/MHz.

The op amp’s wide-input common-mode voltage range accepts input signals 100 mV beyond each rail, enabling direct connection to several sensor types. In addition, the LPV521’s maximum 1-mV input offset voltage (VOS) and 3.5 µV/°C of input offset voltage drift (TCVOS) enable accurate and stable measurement for both high-side and low-side current sensing.

National Semiconductor additionally calls the LPV521 the world’s only nanopower op amp equipped with electromagnetic interference (EMI) suppression filters to reduce unwanted radio-frequency (RF) interference from external sources like mobile phones, motion sensors, and RFID readers. The LPV521 is available now and costs $0.65 each in minimum batches of 1000.

Driver IC For AMOLEDs

Meanwhile, Ricoh Europe BV’s R1285 driver IC provides a dual power supply to active-matrix OLED (AMOLED) display units. AMOLED displays require a dual power supply consisting of a positive and a negative voltage supply. The R1285 offers a small single-chip solution with only a few external components needed to complete the circuitry. Both power supplies include an internal MOSFET driver.

The R1285’s soft-start function prevents high inrush current peaks during the startup sequence. The startup sequence of both outputs is made internally. Once the positive output reaches its nominal level, the negative output will initialize as well. By using the CE pin, the R1285 can be turned off. Both outputs use an embedded auto-discharge function to discharge the remaining output voltage to 0 V rapidly, preventing phenomena such as random graphics on the display during shutdown.

The IC’s undervoltage lockout (UVLO) circuit disables the chip once the input voltage is below a specific threshold. Overcurrent and short protection is embedded to keep the internal drivers off with a latch function once the fault condition exceeds a timeout period, preventing the chip from overheating or damaging other parts on the circuit board. The chip resumes normal operation by using the chip enable or UVLO functions.

Atom Power IC

To optimize the power efficiency of applications using the Intel Atom processor Z5xx series, Dialog Semiconductor has launched the first in a family of power-management ICs (PMICs). According to Dialog, its PMICs improve battery life, simplify design, improve system reliability, require less than half the board space, and cut the bill-of-materials.

From a single supply voltage, the DA6001 provides low-noise supplies to all platform voltage domains and current for system DDR2 memory. Four dc-dc buck converters power the platform hardware engine, the synchronization channel (SCH) core and front-side bus, both internal and external system memory, and the CPU core, meeting the IMVP-6 specification for the Intel Atom processor.

Using Dialog’s patented Smart Mirror technology, six high-performance LDO voltage regulators supply further platform power demands, removing the need for a low-power mode and simplifying power control in the system. A dedicated push-pull LDO is integrated into the device to terminate the address lines of the external RAM, further minimizing external components.

The DA6001 includes a clock synthesizer/driver according to Intel’s CK610 specification, providing all the necessary clocks via three separate fractional division phase-locked loops (PLLs). Two analog signal inputs can be multiplexed to a 10-bit analog-to-digital converter (ADC) for signal measurements and a charge pump, which is integrated to generate the 5-V reference domain even if the input voltage drops below 5 V. An autonomous state machine manages the complete system startup and shutdown procedures as well as the state transitions of the Intel Atom processor during all operational modes.

Samples are available now with volume production and AEC-Q100 qualified volume parts for automotive applications expected sometime during the second half of 2009.

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