Building Technology Power Solutions

The ADP2230 includes two high efficiency, low quiescent current, 800 mA, step-down, dc-to-dc converters in a small, 10-lead, 3 mm × 3 mm, LFCSP package. The total solution requires only five tiny external components. When the ADP2230 is used with three 0603 capacitors and two 2 mm × 2 mm inductors, the total solution size is about 48 mm2, resulting in the smallest footprint solution to meet a variety of portable applications.

The ADP2230 buck regulator uses a proprietary, high speed, current mode, constant frequency, PWM control scheme for excellent stability and transient response. The buck outputs operate out of phase to reduce the input current ripple. To ensure the longest battery life in portable applications, the ADP2230 has a power saving variable frequency mode that reduces the switching frequency under light load conditions.

During logic controlled shutdown, the input is disconnected from the output, and it draws less than 0.1 μA from the input source. The ADP2230 operates from input voltages from 2.3 V to 6.5 V, allowing the use of multiple alkaline, NiMH, or lithium cells and other standard power sources.

The ADP2230 offers multiple options for setting the operating frequency. To maximize light load efficiency, the ADP2230 can operate at a reduced switching frequency in PSM and switch automatically to PWM as the load increases. The ADP2230 can be forced to operate at 2 MHz in PWM only mode when noise considerations are more important than efficiency. The ADP2230 can also be synchronized with a 1.5 MHz to 2.5 MHz external clock via the SYNC pin. When using the external clock synchronization control, both buck outputs operate in phase with the applied clock signal.

The ADP2230 includes an internal power switch, synchronous rectifier, and compensation to minimize external part count and maximize efficiency. Other key protection features include undervoltage lockout to prevent deep battery discharge, internal soft start to prevent input current overshoot at startup, and an integrated, switched resistor, QOD function that automatically discharges the output when the device is disabled. Short-circuit protection and thermal overload protection circuits prevent damage in adverse conditions.

Applications

• Portable and battery-powered equipment
• Automatic meter readers (WSN)
• Point of sales and transaction processing instruments
• Mobile phones
• Digital cameras and audio devices
• Medical instruments
• Medium format display tablets and pads

The LTC4291-1/LTC4292 chipset is a 4-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3bt Type 3 and 4 compliant Power over Ethernet (PoE) systems. The LTC4291-1/LTC4292 is designed to power compliant 802.3af, 802.3at, and 802.3bt PDs. The LTC4291-1/LTC4292 chipset delivers lowest-in-industry heat dissipation by utilizing low R_DS(ON) external MOSFETs and 0.15Ω sense resistance per power channel. A transformer-isolated communication protocol replaces expensive opto-couplers and complex isolated 3.3V supply, resulting in significant BOM cost savings.

Advanced power management features include per-port 14-bit current monitoring, programmable current limit, and versatile fast shutdown of preselected ports. Advanced power management host software is available under a no-cost license. PD detection uses a proprietary multipoint detection mechanism ensuring excellent immunity from false PD identification. Autoclass and 5-event physical classification are supported. The LTC4291-1/LTC4292 includes an I²C serial interface operable up to 1MHz. The LTC4291-1/LTC4292 is pin or I²C programmable to negotiate PD delivered power up to 71.3W.

The LTC4292/LTC4291 chipset is a 4-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3bt Type 3 and 4 compliant Power over Ethernet (PoE) systems. The LTC4292/LTC4291 is designed to power compliant 802.3af, 802.3at, and 802.3bt PDs. The LTC4292/LTC4291 chipset delivers lowest-in-industry heat dissipation by utilizing low-R_DS(ON) external MOSFETs and 0.15Ω sense resistance per power channel. A transformer-isolated communication protocol replaces expensive opto-couplers and complex isolated 3.3V supply, resulting in significant BOM cost savings.

Advanced power management features include perport 14-bit current monitoring, programmable current limit, and versatile fast shut-down of preselected ports. Advanced power management host software is available under a no-cost license. PD detection uses a proprietary multipoint detection mechanism ensuring excellent immunity from false PD identification. Autoclass and 5-event physical classification are supported. The LTC4292/LTC4291 includes an I²C serial interface operable up to 1MHz. The LTC4292/LTC4291 is pin or I²C programmable to negotiate PD delivered power up to 71.3W.

The LT4320/LT4320-1 are ideal diode bridge controllers that drive four N-channel MOSFETs, supporting voltage rectification from DC to 600Hz typical. By maximizing available voltage and reducing power dissipation (see thermograph comparison below), the ideal diode bridge simplifies power supply design and reduces power supply cost, especially in low voltage applications.

An ideal diode bridge also eliminates thermal design problems, costly heat sinks, and greatly reduces PC board area. The LT4320’s internal charge pump supports an all- NMOS design, which eliminates larger and more costly PMOS switches. If the power source fails or is shorted, a fast turn-off minimizes reverse current transients.

The LT4320 is designed for DC to 60Hz typical voltage rectification, while the LT4320-1 is designed for DC to 600Hz typical voltage rectification. Higher frequencies of operation are possible depending on MOSFET size and operating load current.

Applications

• Security Cameras
• Terrestrial or Airborne Power Distribution Systems
• Power-over-Ethernet Powered Device with a Secondary Input
• Polarity-Agnostic Power Input
• Diode Bridge Replacement

The LT4321 is a dual ideal diode bridge controller that enables a Power over Ethernet (PoE) powered device (PD) to receive power in either voltage polarity from RJ-45 data pairs, spare pairs, or both. The LT4321 and eight N-channel MOSFETs replace the eight diodes in a passive PoE rectifier bridge. The LT4321 eases thermal design and increases delivered power.

An internal charge pump allows an all-NMOS bridge eliminating larger and more costly PMOS switches. The LT4321 works with 2-pair and 4-pair applications. High impedance input sense pins prevent reverse current on unused pairs. If the power source fails or is shorted, a fast turn-off minimizes reverse current transients. Unlike discrete ideal bridge solutions, the LT4321 will operate through transients without enabling the MOSFETs on unpowered pairs.

Applications

• PoE/PoE+/ LTPoE++ Powered Devices
• DC Polarity Correction and Ideal Diode-ORing of Telecom Supplies

The LT8608 is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 1.7µA of quiescent current. The LT8608 can deliver 1.5A of continuous current. Low ripple Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mV. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/ UV pin has an accurate 1V threshold and can be used to program V_IN undervoltage lockout or to shut down the LT8608. The PG flag signals when V_OUT is within ±8.5% of the programmed output voltage as well as fault conditions.

The MSOP package includes a SYNC pin to synchronize to an external clock, or to select Burst Mode operation or pulse-skipping with or without spread-spectrum; the TR/SS pin programs soft-start or tracking. The DFN package omits these pins and can be purchased in pulse-skipping or Burst Mode operation varieties.

APPLICATIONS

• General Purpose Step Down
• Low EMI Step Down

Demonstration circuit 2259A is a Daisy Chain isoSPI Battery-Stack Monitor featuring the LTC6811-1. Multiple boards can be linked through a 2-wire isolated serial interface to monitor any number of cells on a stack.

Demonstration circuit 2521A is a 42V, 1.5A micropower synchronous step-down regulator featuring the LT8608/ LT8608B. There are two assembly versions. DC2521A-A is for the LT8608 and DC2521A-B is for the LT8608B.

The LT8608/LT8608B is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator. Top and bottom power switches, compensation components and other necessary circuits are inside of the 2mm × 2mm DFN package to minimize external components and simplify design. The difference LT8608 and LT8608B is the LT8608 works under low ripple Burst Mode^® operation at light load condition, while the LT8608B has pulse-skipping mode for light load. Due to the Burst Mode operation, LT8608 consumes only 1.7μA of quiescent current when output is regulated at 5V. LT8608B has higher quiescent current because of its pulse-skipping mode operation.

The demo board is designed for 5V output from a 5.5V to 42V input. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies.

The demo board has an EMI filter installed. To use the EMI filter, the input should be tied to V_EMI, not V_IN. An inductor L2, which is a 0Ω jumper on the board by default now, can be added in the EMI filter to further reduce the conducted emission.

The LT8608 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this demo manual for DC2521A.

The ADP2230 evaluation board aids in rapid testing of the performance of the ADP2230. The evaluation board ships with the adjustable output option, allowing for testing to be performed on multiple output voltages. The boards come preconfigured to have one output set to 1.2 V, and one output set to 3.3 V. The user can adjust the output by replacing set resistors on the evaluation board.

For more information about the ADP2230 dual buck converter, see the ADP2230 data sheet.

The ADP5090 demonstration platform is a plug and play evaluation board (ADP5090-2-EVALZ) for energy harvesting. The demonstration platform includes the photovoltaic (PV) panel and all of the power management to enable devices to be powered using energy harvesting. It is based on the Alta Devices^™ PV cell, or the IXYS^™ Corporation PV cell, and the ADP5090 energy harvesting power management IC.

The ADP5090 demonstration platform converts light energy to electrical energy. The PV panel converts the light to 0.8 V electrical energy. The ADP5090 boosts the input voltage from 0.8 V to 3.5 V and stores the energy in a supercapacitor.

In addition, there is an on-board, low dropout (LDO) regulator that powers loads at lower voltage rails than the 3.5 V stored in the supercapacitor. The Alta Devices PV cell is a light harvesting gallium arsenide-based cell. The PV cell is optimized for indoor environments, where lux levels are typically 200 lux to 1000 lux.

The ADP5090 is an ultra low power, synchronous, boost dc-to-dc regulator. The ADP5090 runs from input voltages of 0.38 V to 3.3 V and provides a high efficiency solution with an integrated power switch, synchronous rectifier, and battery management. The demo platform provides an easy way to evaluate the device.

Full details about the ADP5090 devices are available in the ADP5090 data sheet and must be consulted when using the ADP5090-2-EVALZ evaluation board.

The demo platform system also plugs directly into the Analog Devices WSN demo platform.