The LTC2927 provides a simple solution to power supply tracking and sequencing requirements. By selecting a few resistors, the supply can be configured to ramp-up and ramp-down with differing ramp rates, voltage offsets, or time delays relative to other supplies or a master signal.By forcing current into a feedback node of an independent supply, the LTC2927 causes the output to track a ramp signal without inserting any pass element losses. Because the current is controlled in an open-loop manner, the LTC2927 does not affect the transient response or stability of the supply. The compact solution at point of load minimizes the trace length of the DC/DC circuit sensitive FB node. Furthermore, it presents a high impedance when power-up is complete, effectively removing it from the DC/DC circuit.Applications VCORE and VI/O Supply Tracking Microprocessor, DSP and FPGA Supplies Multiple Supply Systems Point-of-Load Supplies

The ADP3303 is a member of the ADP3300, ADP3301, andADP3309 family of precision low dropout anyCAP voltage regulators. The ADP3303 stands out from the conventional LDOs with a different architecture, an enhanced process, and adifferent package. Its patented design requires only a 0.47 μFoutput capacitor for stability. This device is insensitive to capacitor Equivalent Series Resistance (ESR) and is stable with any good quality capacitor, including ceramic types (MLCC) forspace restricted applications. The ADP3303 achievesexceptional accuracy of ±0.8% at room temperature and ±1.4%overall accuracy over temperature, line, and load regulations.The dropout voltage of the ADP3303 is only 180 mV (typical) at 200 mA.In addition to the architecture and process, the Analog Devices, Inc., proprietary thermally enhanced package (Thermal Coastline)can handle 1 W of power dissipation without external heatsink or large copper surface on the printed circuit board (PCB).This keeps PCB real estate to a minimum and makes theADP3303 very attractive for use in portable equipment.The ADP3303 operates with a wide input voltage range from 3.2 V to 12 V and delivers a load current in excess of 200 mA.It features an error flag that signals when the device is about to lose regulation or when the short circuit or thermal overloadprotection is activated. Other features include shutdown and optional noise reduction capabilities. The ADP3300, ADP3301,and ADP3309 anyCAP LDO family offers a wide range of output voltages and output current levels:ADP3300 (50 mA, SOT-23)ADP3301 (100 mA) ADP3302 (100 mA, Dual Output)Applications Cellular telephones Notebook, palmtop computers Battery powered systems Portable instruments Post regulator for switching supplies Bar code scanners

The ADP3303 is a member of the ADP3300, ADP3301, andADP3309 family of precision low dropout anyCAP voltage regulators. The ADP3303 stands out from the conventional LDOs with a different architecture, an enhanced process, and adifferent package. Its patented design requires only a 0.47 μFoutput capacitor for stability. This device is insensitive to capacitor Equivalent Series Resistance (ESR) and is stable with any good quality capacitor, including ceramic types (MLCC) forspace restricted applications. The ADP3303 achievesexceptional accuracy of ±0.8% at room temperature and ±1.4%overall accuracy over temperature, line, and load regulations.The dropout voltage of the ADP3303 is only 180 mV (typical) at 200 mA.In addition to the architecture and process, the Analog Devices, Inc., proprietary thermally enhanced package (Thermal Coastline)can handle 1 W of power dissipation without external heatsink or large copper surface on the printed circuit board (PCB).This keeps PCB real estate to a minimum and makes theADP3303 very attractive for use in portable equipment.The ADP3303 operates with a wide input voltage range from 3.2 V to 12 V and delivers a load current in excess of 200 mA.It features an error flag that signals when the device is about to lose regulation or when the short circuit or thermal overloadprotection is activated. Other features include shutdown and optional noise reduction capabilities. The ADP3300, ADP3301,and ADP3309 anyCAP LDO family offers a wide range of output voltages and output current levels:ADP3300 (50 mA, SOT-23)ADP3301 (100 mA) ADP3302 (100 mA, Dual Output)Applications Cellular telephones Notebook, palmtop computers Battery powered systems Portable instruments Post regulator for switching supplies Bar code scanners

The ADP3335 is a member of the ADP330x family ofprecision low dropout any CAP voltage regulators. TheADP3335 operates with an input voltage range of +2.6 Vto +12 V and delivers a continuous load current up to 500mA. The ADP3335 stands out from the conventionalLDOs with the lowest thermal resistance of any MSOP-8package and an enhanced process that enables it to offerperformance advantages beyond its competition. Its patenteddesign requires only a 1.0 µF output capacitor forstability. This device is insensitive to output capacitorEquivalent Series Resistance (ESR), and is stable with anygood quality capacitor, including ceramic (MLCC) typesfor space-restricted applications. The ADP3335 achieves exceptional accuracy of ±0.9% at room temperature and ±1.8% over temperature, line and load variations. The dropout voltage of the ADP3335 is only 200 mV (typical) at 500 mA.This device also includes a safety currentlimit, thermal overload protection and a shutdown feature.In shutdown mode, the ground current is reduced to lessthan 2 µA. The ADP3335 has ultralow quiescent current60 µA (typ) in light load situations.

The LT3468/LT3468-1/LT3468-2 are highly integrated ICs designed to charge photoflash capacitors in digital and film cameras. A patented control technique* allows for the use of extremely small transformers. Each device contains an on-chip high voltage NPN power switch. Output voltage detection* is completely contained within the device, eliminating the need for any discrete zener diodes or resistors. The output voltage can be adjusted by simply changing the turns ratio of the transformer. The LT3468 has a primary current limit of 1.4A, the LT3468-2 has a 1A limit, and the LT3468-1 has a 0.7A limit. These different current limit levels result in well controlled input currents of 500mA for the LT3468, 375mA for the LT3468-2 and 225mA for the LT3468-1. Aside from the differing current limit, the three devices are otherwise equivalent.The CHARGE pin gives full control of the part to the user. Driving CHARGE low puts the part in shutdown. The DONE pin indicates when the part has completed charging. The LT3468 series of parts are available in tiny low profile (1mm) SOT-23 packages.Applications Digital / Film Camera Flash PDA / Cell Phone Flash Emergency Strobe

The LTM4652 is a source/sink dual ±25A or single ±50A output switching mode step-down DC/DC μModule® (micromodule) regulator with ±1.5% total DC output error. Included in the package are the switching controllers, power MOSFETs, inductors and all supporting components. Operating from an input voltage range of 4.5V to 18V, the LTM4652 supports two outputs with an output voltage range of 0.6V to 7.5V, each set by a single external resistor. Its high efficiency design delivers up to ±25A continuous current for each output. Only a few input and output capacitors are needed. Adjustable control loop compensation allows for fast transient response to minimize output capacitance when powering FPGAs, ASICs, and processors.Fault protection features include input and output overvoltage and bidirectional overcurrent protection. The LTM4652 is offered in a 16mm × 16mm × 4.92mm BGA package.APPLICATIONS Test and Measurement Instrumentation Telecom and Networking Equipment Industrial Equipment

The ADM1169 Super Sequencer® is a configurable supervisory/ sequencing device that offers a single-chip solution for supply monitoring and sequencing in multiple supply systems. In addition to these functions, the ADM1169 integrates a 12-bit ADC and four 8-bit voltage output DACs. These circuits can be used to implement a closed-loop margining system that enables supply adjustment by altering either the feedback node or reference of a dc-to-dc converter using the DAC outputs. Supply margining can be performed with a minimum of external components. The margining loop can be used for in-circuit testing of a board during production (for example, to verify board functionality at –5% of nominal supplies), or it can be used dynamically to accurately control the output voltage of a dc-to-dc converter. The device also provides up to eight programmable inputs for monitoring undervoltage faults, overvoltage faults, or out-of-window faults on up to eight supplies. In addition, there are eight programmable outputs that can be used as logic enables. Six of these programmable outputs can also provide up to a 12 V output for driving the gate of an N-FET that can be placed in the path of a supply. The logical core of the device is a sequencing engine (SE). This state machine-based construction provides up to 63 different states. This design enables very flexible sequencing of the outputs, based on the condition of the inputs. A block of nonvolatile EEPROM is available that can be used to store user-defined information and may also be used to hold a number of fault records that are written by the sequencing engine defined by the user when a particular fault or sequence occurs. The ADM1169 is controlled via configuration data that can be programmed into an EEPROM. The entire configuration can be programmed using an intuitive GUI-based software package provided by Analog Devices, Inc.

The ADM1275 is a hot-swap controller that allows a circuit board to be removed from or inserted into a live backplane. It also features current and voltage readback via an integrated 12-bit analog-to-digital converter (ADC), accessed using a PMBus™ interface. The load current is measured using an internal current sense amplifier that measures the voltage across a sense resistor in the power path via the SENSE+ and SENSE− pins. A default limit of 20 mV is set, but this limit can be adjusted, if required, using a resistor divider network from the internal reference voltage to the ISET pin.The ADM1275 limits the current through the sense resistor by controlling the gate voltage of an external N-channel FET in the power path, via the GATE pin. The sense voltage—and, therefore, the load current—is maintained below the preset maximum. The ADM1275 protects the external FET by limiting the time that the FET remains on while the current is at its maximum value. This current limit time is set by the choice of capacitor connected to the TIMER pin. In addition, a foldback resistor network can be used to actively lower the current limit as the voltage across the FET is increased. This helps to maintain constant power in the FET and allows the safe operating area (SOA) to be adhered to in an effective manner.In case of a short-circuit event, a fast internal overcurrent detector responds within 370 ns and signals the gate to shut down. A 1500 mA pull-down device ensures a fast FET response. The ADM1275 features overvoltage and undervoltage protection, programmed using external resistor dividers on the UV and OV pins. A PWRGD signal can be used to detect when the output supply is valid, using the FLB pin to monitor the output. GPO pins can be configured as various output signals that can be asserted when a programmed current or voltage level is reached.The 12-bit ADC can measure the current in the sense resistor, as well as the supply voltage on the SENSE+ pin or the output voltage. A PMBus interface allows a controller to read current and voltage data from the ADC. Measurements can be initiated by a PMBus command. Alternatively, the ADC can run continuously, and the user can read the latest conversion data whenever required. Up to four unique PMBus addresses can be selected, depending on the way that the ADR pin is connected. The ADM1275-1 and ADM1275-3 are available in a 20-lead QSOP and 20-lead LFCSP and have a LATCH pin that can be configured for automatic retry or latch-off when an overcurrent fault occurs. The ADM1275-2 is available in a 16-lead QSOP with latch-off mode only.Applications Power monitoring and control/power budgeting Central office equipment Telecommunication and data communication equipment PCs/servers

Voltage References

Switching Voltage Regulators 3.3/5V or Adjustable Step-Up Step-Down