DUAL LDO WITH MICROCONTROLLER RESET FUNCTION

Demonstration circuit 2788A is a boost LED driver featuring the LT®3950. This demonstration circuit powers a string of LEDs at 330mA. The step-up topology can be used to drive a string of up to 28V of LEDs as assembled. The maximum output voltage capability of the LT3950 is 60V. DC2788A runs from an input voltage range of 6V to 24V as built. It also runs at 2MHz and has the capability to turn on spread spectrum frequency modulation (SSFM) for a frequency range of 2.0MHz to 2.5MHz. Dimming control can be achieved with analog dimming or PWM dimming—either from an external or internally-generated clock source. DC2788A features undervoltage lockout (UVLO) set at 6.6V with a 1.0V hysteresis for turn-on. The UVLO voltage, LED current, output voltage range, switching frequency, brightness control, SSFM, and the topology can all be adjusted with simple modifications to the demonstration circuit. LT3950 is a monolithic 1.5A peak switch current, 60V LED driver. The guaranteed peak switch current rating of the IC is 1.5A and this is important to know when calculating maximum output current at a given LED voltage and input voltage for a boost converter. The LT3950 features SSFM and a well-controlled SW node for low emissions. A frequency range of 200kHz to 2MHz and a high-side PWMTG PWM-dimming MOSFET makes this a very versatile IC for many applications. It can be used for boost, buck-boost mode and buck mode LED driver applications. The PWMTG MOSFET not only provides high PWM dimming ratio capability, but it also serves as a short-circuit protection device. The FAULT flag indicates when there is either a short-circuit or open-LED fault at the output. The demo circuit is designed to be easily reconfigured to suit other applications, including the example schematics in the data sheet. Consult technical support for assistance. High voltage operation, 3V input voltage operation, multiple topologies, small-and-compact size, fault protection, low EMI, and multiple brightness control options make the LT3950 flexible and powerful for compact, noise-sensitive LED driver solutions. The LT3950JMSE featured on this demo circuit is available in a thermally enhanced 16-lead plastic MSOP package. The LT3950 data sheet must be read in conjunction with this demo manual to properly use or modify demo circuit DC2788A.

TPS61070 Evaluation Module

The LT8391 is a synchronous 4-switch buck-boost LED controller that regulates LED current from input voltage above, below, or equal to the output voltage. The proprietary peak-buck peak-boost current mode control scheme allows adjustable and synchronizable 150kHz to 650kHz fixed frequency operation, or internal ?15% triangle spread spectrum operation for low EMI. With 4V to 60V input, 0V to 60V output, and seamless low noise transitions between operation regions, the LT8391 is ideal for LED driver and battery charger applications in automotive, industrial, and battery-powered systems.The LT8391 provides both internal (up to 128:1) and external (up to 2000:1) LED current PWM dimming with a high-side PMOS switch. Two CTRL pins provide flexible 20:1 analog dimming with ?3% LED current accuracy at 100mV full scale. Fault protection is provided to detect an open or short LED condition, during which the LT8391 retries, latches off, or keeps running. Switching Frequency Max Output Power LT8391 Adjustable 150kHz - 650kHz 450W+ LT8391A 2MHz 50W+ APPLICATIONS Automotive Head Lamps/Running Lamps High Power LED Lighting

The ADM1170 is a Hot Swap controller that allows a board to be safely inserted and removed from a live backplane. This is achieved using a pass FET with a current control loop that monitors the input current using a sense resistor. An internal charge pump is used to enhance the gate of theexternal high side N-channel FET. When an over current condition is detected the gate voltage of the FET is reduced to limit the current flowing through the sense resistor. The ADM1170 operates with a supply voltage ranging from 2.7V to 16.5V. Using separate SENSE pins from VCC the ADM1170 allows for the hot swap of supplies ranging down to 1.6V. During an overcurrent condition the timer cap determines the amount of time the FET will remain in this condition. The ON (ON-CLR) pin is the enable input for the device and also acts as a latched fault reset for the ADM1170-2 model. The SS pin is used to control the inrush current profile by ramping up the current sense limit at a rate set by the SS capacitor. This device is available in two options: the ADM1170-1 will automatic retry for over-current fault and the ADM1170-2 will latch-off for an over-current fault. The ADM1170 is packaged in an 8-lead TSOT packageAPPLICATIONS Hot Swap Board Insertion ? Line Cards, Raid Systems Electronic Circuit Breaker Industrial High Side Switch/Circuit Breaker

LP38511 Thin TO-263 800 mA Fast-Transient Response LDO with Error Flag Evaluation Board

The LTC1730 is a complete pulse charger for 1-cell lithium-ion batteries. When charging a depleted cell, the internal MOSFET is fully on allowing the current limited input power source to provide charge current to the battery, virtually eliminating heat generation in the charger.As the battery accepts charge and approaches the programmed voltage, the internal MOSFET begins switching off and on with the duty cycle gradually decreasing as the battery approaches a fully charged condition. A programmable timer ends the charge cycle. The end-of-charge condition is indicated at the CHRG pin when the average charge current falls to C/10. Removing the input voltage puts the LTC1730 into a sleep mode, dropping the battery current drain to less than 1?A (maximum).An external sense resistor limits the maximum charge current as a safety precaution against a user connecting a wall adapter with the incorrect or no current limit. The internal MOSFET prevents reverse battery current from flowing if the input voltage is shorted to ground, eliminating the need for a blocking diode.The LTC1730-4 is available in the 16-pin SSOP package and the LTC1730-4.2 is available in the 8-pin SO package.Applications Standalone Lithium-Ion Battery Charger Handheld Computers Cellular Telephones

The LT1339 is a high power synchronous current mode switching regulator controller. The IC drives dual N-channel MOSFETs to create a single IC solution for high power DC/DC converters in applications up to 60V.The LT1339 incorporates programmable average current limiting, allowing accurate limiting of DC load current independent of inductor ripple current. The IC also incorporates user-adjustable slope compensation for minimization of magnetics at duty cycles up to 90%.The LT1339 timing oscillator operating frequency is programmable and can be synchronized up to 150kHz. Minimum off-time operation provides main switch protection. The IC also incorporates a soft start feature that is gated by both shutdown and undervoltage lockout conditions.An output phase reversal pin allows flexibility in configuration of converter types, including inverting and negative topologies.Applications 48V Telecom Power Supplies Personal Computers and Peripherals Distributed Power Converters Industrial Control Systems Lead-Acid Battery Backup Systems Automotive and Heavy Equipment

The LTC6905 precision, programmable silicon oscillator is easy to use and occupies very little board space. It requires only a single resistor to set the output frequency from 17MHz to 170MHz with a typical frequency error of 0.5% or less.The LTC6905 operates with a single 2.7V to 5.5V power supply and provides a rail-to-rail, 50% duty cycle square wave output. The CMOS output driver ensures fast rise/fall times and rail-to-rail switching. Operation is simple: A single resistor, RSET, between 10K to 25K is used to set the frequency, and an internal three-state divider (DIV input) allows for division of the master clock by 1, 2 or 4, providing three frequencies for each RSET value.The LTC6905 features a proprietary feedback loop that linearizes the relationship between RSET and frequency, eliminating the need for tables to calculate frequency. The oscillator can be easily programmed using the simple formula outlined below:See first page of Data Sheet for formula?For higher accuracy, fixed frequency versions that includean internal frequency-setting resistor, see the LTC6905-XXX Series datasheet.Applications High Frequency Precision Oscillator High Speed Data Bus Clock Fixed Crystal Oscillator Replacement Ceramic Oscillator Replacement

Clock & Timer Development Tools LMX2485E EVAL BOARD