Demonstration circuit 649 is a Telecom isolated DC/DC converter featuring the LTC3803 constant frequency current mode flyback controller. The DC649 converts an isolated 36V to 72V input and provides 2A of output current at 5V. The 200kHz constant frequency operation is maintained down to very light load to reduce low frequency noise generated over a wide range of load current. The converter provides high output voltage accuracy (typically ±2%) over wide load range with no minimum load requirement.

The LTC3412A is a high efficiency monolithic synchronous, step-down DC/DC converter utilizing a constant frequency, current mode architecture. It operates from an input voltage range of 2.25V to 5.5V and provides a regulated output voltage from 0.8V to 5V while delivering up to 3A of output current. The internal synchronous power switch with 77m? on-resistance increases efficiency and eliminates the need for an external Schottky diode. Switching frequency is set by an external resistor or can be synchronized to an external clock. 100% duty cycle provides low dropout operation extending battery life in portable systems. OPTI-LOOP? compensation allows the transient response to be optimized over a wide range of loads and output capacitors. The LTC3412A can be configured for either Burst Mode operation or forced continuous operation. Forced continuous operation reduces noise and RF interference while Burst Mode operation provides high efficiency by reducing gate charge losses at light loads. In Burst Mode operation, external control of the burst clamp level allows the output voltage ripple to be adjusted according to the application requirements.APPLICATIONS Point-of-Load Regulation Notebook Computers Portable Instruments Distributed Power Systems

Demonstration Circuit 658 is a complete power management system using the LTC3456 for portable applications powered by a wall adapter, a USB port or a 2-cell alkaline battery, in that order of priority. DC658 provides three outputs: a 1.8V, 200mA core supply, a 3.3V, 150mA main supply, and a 3.3V, 50mA Hot Swap supply. All outputs are discharged to ground during shutdown. The synchronous buck (1.8V output) and the second converter (which operates as a buck or a boost depending on the power source, and provides 3.3V @ 150mA and 3.3V @ 50mA outputs) accept a 2V to 3.2V battery input or USB/Wall adapter input.

The LTC1844 Series are low noise VLDO? (very low dropout) linear regulators designed for low power/portable applications. These regulators can operate from input voltages as low as 1.6V. Typical output noise is only 30?VRMS and typical dropout for the LTC1844-3.3 is just 90mV at the maximum load current of 150mA, reducing to 30mV at 50mA.The internal P-channel MOSFET pass transistor requires no base current, allowing the device to draw only 35?A during normal operation, independent of the dropout voltage and load current. The quiescent current falls to a negligible 10nA during shutdown.Other features include high output voltage accuracy, excellent transient response, stability with ultralow ESR ceramic capacitors as small as 1?F, reverse-battery and reverse-current protection, short-circuit and thermal overload protection and output current limiting.The LTC1844 regulators are available in a low profile (1mm) SOT-23 (ThinSOT?) package.Applications Portable Instruments and Battery-Powered Systems Bluetooth/802.11 Cards Cellular Phones PDAs and Notebook Computers

DC690A: Demo Board for the LT3420 Photoflash Capacitor Chargers with Automatic Refresh.

DC711A-A: Demo Board for the LT3468 Photoflash Capacitor Chargers in ThinSOT.

The LTC4063 is a standalone linear charger for single cell lithium-ion batteries with an adjustable low dropout linear regulator (LDO). The adjustable LDO regulates an output voltage between 1.2V to 4.2V at up to 100mA load current. When the input supply (wall adapter or USB supply) is removed, the LDO regulates the output voltage without interruption. The battery charger and LDO regulator can be enabled individually.No external sense resistor or external blocking diode is required for charging due to the internal MOSFET architecture. Internal thermal feedback regulates the charge current to maintain a constant die temperature during high power operation or high ambient temperature conditions. The float voltage is fixed at 4.2V and the charge current is programmed with an external resistor. Charge termination methods include minimum charge current or maximum time. With power applied, the LTC4063 can be put into shutdown mode to reduce the supply current to 35?A and the battery drain current to less than 2?A.Other features include smart recharge, undervoltage lockout, LDO current limiting and a charge status pin to indicate when the charge cycle has completed.Applications Handheld Computers Portable MP3 Players Digital Cameras

Demonstration circuit 760 is a dual, output, 1.1MHz Boost/Inverter in a 3mm x 3mm DFN featuring the LT3472EDD. The demo circuit demonstrates small size and low component count in a Boost Circuit and an Inverting Circuit. The Boost Converter is designed to convert a 2.7V–4.2V input to 15V output at 25mA– 45mA load. The Inverting Circuit generates a –8V output at 35mA–65mA from the same input. Since the maximum VIN of the LT3472EDD is 16V, this demo circuit will work well at higher inputs. The only limitation is the 10V rating of the input capacitor.

Demonstration circuit 761 is a low noise regulated charge pump featuring the LTC3204 (Burst Mode operation) in the 2 × 2 DFN package. There are two assembly versions, DC761A-A and DC761A-B for the LTC3204-5 (5V output) and LTC3204-3.3 (3.3V output) respectively. The DC761A-B produces a regulated 3.3V output from a 1.8V to 4.5V input. The guaranteed output current is 50mA from VIN between 1.9V and 4.5V, and 40mA for VIN less than 1.9V. The circuit requires only three tiny 0603 surface mount capacitors and uses minimal board space. No inductor or diodes are needed. The circuit features automatic Burst Mode® operation at light loads to maintain low supply current.

The LT1618 step-up DC/DC converter combines a traditional voltage feedback loop and a unique current feedback loop to operate as a constant-current, constant-voltage source. This fixed frequency, current mode switcher operates from a wide input voltage range of 1.6V to 18V, and the high switching frequency of 1.4MHz permits the use of tiny, low profile inductors and capacitors. The current sense voltage is set at 50mV and can be adjusted using the IADJ pin.Available in the 10-Pin (3mm x 3mm) Exposed Pad DFN and 10-pin MSOP packages, the LT1618 provides a complete solution for constant-current applications.Applications LED Backlight Drivers USB Powered Boost/SEPIC Converters Input Current Limited Boost/SEPIC Converters Battery Chargers