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Hotswap circuits rely on the thermal capacitance of the series-limiting MOSFET to dissipate the large transient energy under current- or power-limit operation. The peakjunction temperature must be controlled in order to achieve a robust design. The constant-power MOSFET protection of the TPS2490 provides a simple method to useinformation provided by MOSFET manufacturers to determine peak junct

This reference design is synchronous buck-boost converter that can deliver up to 3.8 A of continuous current at -5 V from a 5 V input. This topology uses a synchronous buck controller (TPS5103) referenced to the negative output rail. The synchronous MOSFETs allow this design to achieve a peak eff

DC1436A is a 16-Channel High Voltage Boost LED Driver featuring the LT3754. The LT3754 drives up to 50mA per string and has a maximum LED string voltage of 45V. The VIN terminal is powered from an 8V to 14V input supply and is distinct from the 24V PVIN supply (20V to 28V) for best thermal performance. Overvoltage protection is set at 55V in case the LEDs are removed from the circuit. If the LEDs are opened, the FAULT terminal output flag goes low and reports the fault condition. If one or more of the 16 LED channels is not used, its LED pin or terminal should be tied to VOUT (LED+) to disable it. Multiple channels can be tied in parallel by tying their LED1-LED16 pins together.

The LTC4227 offers ideal diode-OR and Hot Swap? functions for two power rails by controlling external Nchannel MOSFETs. MOSFETs acting as ideal diodes replace two high power Schottky diodes and the associated heat sinks, saving power and board area. A Hot Swap control MOSFET allows a board to be safely inserted and removed from a live backplane by limiting inrush current. The supply output is also protected against short-circuit faults with a fast acting current limit and internal timed circuit breaker.The LTC4227 regulates the forward voltage drop across the MOSFETs to ensure smooth current transfer from one supply to the other without oscillation. The ideal diodes turn on quickly to reduce the load voltage droop during supply switchover. If the input supply fails or is shorted, a fast turn-off minimizes reverse-current transients.The LTC4227 allows turn-on/off control, and reports fault and power good status for the supply. Part Overcurrent Fault Start-Up Delay LTC4227-1 Latch Off 100ms LTC4227-2 Retry 100ms LTC4227-3 Latch Off 1.6ms LTC4227-4 Retry 1.6ms Applications Redundant Power Supplies and Supply Holdup Computer Systems and Servers Telecom Networks

This application report demonstrates the use of the Micrium uC/OS-II real-time kernel on an MSP430 microcontroller with very low memory overhead. Suggestions on how to effectively use the features of MSP430 and µC/OS-II to optimize a project are included. This report also explains how to effectively use MSP430 ultralow-power modes with uC/OS-II projects.

The LTC4270/LTC4271 chipset is a 12-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3at Type 1 and Type 2 (high power) compliant Power over Ethernet (PoE) systems. Transformer-isolated communication protocol replaces expensive opto-couplers and complex isolated 3.3V supply resulting in significant BOM cost savings. The LTC4270/LTC4271 chipset delivers lowest-in-industry heat dissipation by utilizing low-RDS(ON) external MOSFETs and 0.25? sense resistors.Advanced power management features include per-port 12?bit current monitoring ADCs, DAC-programmable current limit, and versatile fast shut-down of preselected ports. Advanced power management host software is available under a no-cost license. PD discovery uses a proprietary dual-mode 4-point detection mechanism ensuring excellent immunity from false PD detection. Midspan PSEs are supported with 2-event classification and a 2 second backoff timer. The LTC4270/LTC4271 includes an I2C serial interface operable up to 1MHz.The LTC4270/LTC4271 is available in multiple power grades allowing delivered PD power up to 90W.Applications PoE PSE Switches/Routers PoE PSE Midspans

The AD5590 is a 16-channel input and 16-channel output analog I/O port with eight uncommitted amplifiers, operating from a single 4.5 V to 5.25 V supply. The AD5590 comprises 16 input channels multiplexed into a 1 MSPS, 12-bit successive approximation ADC with a sequencer to allow a preprogrammed selection of channels to be converted sequentially. The ADC contains a low noise, wide bandwidth track-and-hold amplifier that can handle input frequencies in excess of 1 MHz.The conversion process and data acquisition are controlled using ASYNC and the serial clock signal, allowing the device to easily interface with microprocessors or DSPs. The input signal is sampled on the falling edge of ASYNC and conversion is also initiated at this point. There are no pipeline delays associated with the ADC. By setting the relevant bits in the control register, the analog input range for the ADC can be selected to be a 0 V to VREFA input or a 0 V to 2 ? VREFA with either straight binary or twos complement output coding. The conversion time is determined by the ASCLK frequency because it is also used as the master clock to control the conversion.The DAC section of the AD5590 comprises sixteen 12-bit DACs divided into two groups of eight. Each group has an on-chip reference. The on-board references are off at power-up, allowing the use of external references. The internal references are enabled via a software write.The AD5590 incorporates a power-on reset circuit that ensures that the DAC outputs power up to 0 V and remain powered up at this level until a valid write takes place. The DAC contains a power-down feature that reduces the current consumption of the device and provides software-selectable output loads while in power-down mode for any or all DAC channels. The outputs of all DACs can be updated simultaneously using the LDAC function, with the added functionality of user-selectable DAC channels to simultaneously update. There is also an asynchronous CLR that updates all DACs to a user-programmable code: zero scale, midscale, or full scale.The AD5590 contains eight low noise, single-supply amplifiers. These amplifiers can be used for signal conditioning for the ADCs, DACs, or other independent circuitry, if required.APPLICATIONS Optical Line Cards (Monitoring and Control) Base Stations General Purpose Analog I/O Monitoring and control

The short and long term reliability of National Semiconductor's interface circuits like any integrated circuit is very dependent on its environmental condition. Beyond the mechanical/environmental factors nothing has a greater influence on this reliability than the electrical and thermal stress seen by the integrated circuit. Both of these stress issues are specifically addressed on every inter

The AD9959 consists of four direct digital synthesizer (DDS)cores that provide independent frequency, phase, and amplitudecontrol on each channel. This flexibility can be used to correct imbalances between signals due to analog processing, such asfiltering, amplification, or PCB layout-related mismatches.Because all channels share a common system clock, they areinherently synchronized. Synchronization of multiple devices is supported.The AD9959 can perform up to a 16-level modulation of fre-quency, phase, or amplitude (FSK, PSK, ASK). Modulation isperformed by applying data to the profile pins. In addition, theAD9959 also supports linear sweep of frequency, phase, or amplitude for applications such as radar and instrumentation. The AD9959 serial I/O port offers multiple configurations to provide significant flexibility. The serial I/O port offers an SPI-compatible mode of operation that is virtually identical to the SPI operation found in earlier Analog Devices, Inc., DDS products. Flexibility is provided by four data pins (SDIO_0/SDIO_1/SDIO_2/SDIO_3) that allow four programmable modes of serial I/O operation.The AD9959 uses advanced DDS technology that provides low power dissipation with high performance. The device incorporates four integrated, high speed 10-bit DACs with excellent wideband and narrow-band SFDR. Each channel has a dedicated 32-bit frequency tuning word, 14 bits of phase offset, and a 10-bit output scale multiplier. The DAC outputs are supply referenced and must be terminated into AVDD by a resistor or an AVDD center-tapped transformer. Each DAC has its own programmable reference to enable different full-scale currents for each channel. The DDS acts as a high resolution frequency divider with the REFCLK as the input and the DAC providing the output. The REFCLK input source is common to all channels and can be driven directly or used in combination with an integrated REFCLK multiplier (PLL) up to a maximum of 500 MSPS. The PLL multiplication factor is programmable from 4 to 20, in integer steps. The REFCLK input also features an oscillator circuit to support an external crystal as the REFCLK source. The crystal must be between 20 MHz and 30 MHz. The crystal can be used in combination with the REFCLK multiplier.The AD9959 comes in a space-saving 56-lead LFCSP package. The DDS core (AVDD and DVDD pins) is powered by a 1.8 V supply. The digital I/O interface (SPI) operates at 3.3 V and requires DVDD_I/O (Pin 49) be connected to 3.3 V. The AD9959 operates over the industrial temperature range of ?40?C to +85?C.APPLICATIONSAgile local oscillators Phased array radars/sonars Instrumentation Synchronized clocking RF source for AOTF

The TIDA-00170 is a reference design for industrial control Analog Mixed Input Output Modules. The design implements four channel analog input & two channel analog output. The analog input channels can measure all standard industrial voltages up to ±10V and current inputs up to 24mA. The two simultaneous analog outputs can source voltage up to ±10V and current up to 24mA.The reference design includes the necessary on-board protection circuit & is tested for IEC61000-4 standard – EFT: ESD and Surge requirements with IO Controller platform. The protection circuitry does not negatively affect the design and test results showed typical unadjusted errors were less than 0.1% of the full-scale range (FSR) for the analog input channel and less than 0.2% FSR for the analog output channel.

The ADATE320 is a complete, single-chip ATE solution that performs the pin electronics functions of a driver, comparator, and active load (DCL), and a four quadrant per pin parametric measurement unit (PPMU). Dedicated 16-bit digital-to-analog converters (DACs) with on-chip calibration registers provide all the necessary dc levels for operation of the device.The driver features three active modes: high, low, and terminate, as well as a high impedance inhibit state. The inhibit state, in conjunction with the integrated dynamic clamps, facilitates significant attenuation of transmission line reflections when the driver is not actively terminating the line. The open-circuit drive capability is ?1.5 V to +4.5 V to accommodate a standard range of ATE and instrumentation applications.The ADATE320 can be used as a dual, single-ended pin electronics channel or as a single differential channel. In addition to per channel high speed window comparators, the ADATE320 provides a programmable threshold differential comparator for differential ATE applications.All dc levels for DCL and PPMU functions are generated by dedicated, on-chip, 16-bit DACs. To facilitate the programming of accurate levels, the ADATE320 includes an integrated calibration function to correct for the gain and offset errors of each functional block. Correction coefficients can be stored on chip, and any values written to the DACs adjust automatically using the appropriate correction factors.The ADATE320 uses a serial programmable interface (SPI) bus to program all functional blocks, DACs, and on-chip calibration constants. It also has an on-chip temperature sensor and overvolt-age/undervoltage fault clamps that monitor and report the device temperature and any output pin or transient PPMU voltage faults that may occur during operation.The ADATE320 is available in two options. The standard option has high speed comparator outputs with 250 mV output swing. The ADATE320-1 has 400 mV output swing. See the Ordering Guide for more information.APPLICATIONSAutomatic test equipment (ATE)Semiconductor/board test systemsInstrumentation and characterization equipment

The popularity of companding or complementary noise reduction systems is self-evident. Nearly allmedium to high quality cassette tape decks include either Dolby&regB or Dolby C type noise reduction. Ascant few have different systems such as dbx or Hi-Com. The universal appeal of compandors to n.r.system designers is the amount of noise reduction they can offer yet one of the major reasons t

This application report presents an overview on the differences among the TPS6501x family members. Devices included are the TPS65010, TPS65011, TPS65012,TPS65013, and TPS65014. It is intended to assis