Tag Archives: Step Down

Buck battery charger handles multiple chemistries

4015

by Susan Nordyk @ edn.com:

The LTC4015 synchronous step-down battery charger controller from Linear Technology offers charge current of up to 20 A, multiple-chemistry operation, and onboard digital telemetry. The controller transfers power from a variety of input sources, such as wall adapters and solar panels, to a Li-Ion polymer, LiFePO4, or lead-acid battery stack with system load up to 35 V.

Operating over an input voltage range of 4.5 V to 35 V, the LTC4015 provides ±5% charge-current regulation up to 20 A and ±0.5% charge-voltage regulation. While a host microcontroller is required to access the most advanced features of the LTC4015, the use of an I2C port is optional.

Buck battery charger handles multiple chemistries – [Link]

35VIN & VOUT battery charge controller delivers up to 20A

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4015

LTC4015 is a highly integrated, high voltage multichemistry synchronous step-down battery charger controller with onboard telemetry functions. The device efficiently transfers power from a variety of input sources, such as wall adapters and solar panels, to a Li-Ion/Polymer, LiFePO4 or lead-acid battery stack and system load up to 35V.

It provides advanced system monitoring and management functionality, including battery Coulomb counting and health monitoring. While a host microcontroller is required to access the most advanced features of the LTC4015, the use of an I²C port is optional. The main charging features of the product can be adjusted using pin-strap configurations and programming resistors.

35VIN & VOUT battery charge controller delivers up to 20A – [Link]

Buck controller allows 48V to 1V direct step-down

Intersil 8117

by Richard Quinnell @ edn.com:

Aiming to simplify design and increase power density in industrial systems, Intersil has developed the ISL8817 synchronous buck controller. The device accepts DC input voltages from 4.5V to 60 V and produces a selectable output voltage between 0.6V and 54V at up to 20A output current. Able to operate over a wide switching frequency (100 kHz to 2 MHz) with a low duty cycle (40 nsec minimum on time), the controller is able to step down from a 48V source to a 1V output in a single stage. This allows industrial applications using a 48V power distribution bus to provide the many voltages that modern CPUs and FPGAs require without the need for an intermediate low-voltage stage. This both increases power density in such systems as well as reducing conversion losses.

Buck controller allows 48V to 1V direct step-down – [Link]

LT8616 – Dual 42V Synchronous Monolithic Step-Down Regulator with 6.5μA Quiescent Current

 

8616

The LT8616 is a high efficiency dual synchronous monolithic step-down switching regulator with an input voltage range of 3.4V to 42V. Its dual channel design delivers independent 2.5A and 1.5A continuous current to outputs as low as 0.8V. A dual channel synchronous rectification topology delivers up to 95% efficiency while Burst Mode operation keeps quiescent current under 6.5μA (both channels enabled) in no-load standby conditions, making it ideal for always-on systems. Switching frequency can be programmed from 200kHz to 3MHz and is synchronizable throughout this range. The LT8616’s 35ns minimum on-time enables 16V to 1.8V step-down conversions, while switching at 2MHz helps designers avoid critical noise-sensitive frequency bands, such as AM radio while having a very compact solution footprint.

LT8616 – Dual 42V Synchronous Monolithic Step-Down Regulator with 6.5μA Quiescent Current – [Link]

LT8640 – 42V, 5A Synchronous Step-Down Silent Switcher

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LT8640

The LT8640 step-down regulator features Silent Switcher architecture designed to minimize EMI/EMC emissions while delivering high efficiency at frequencies up to 3MHz. Assembled in a 3mm × 4mm QFN, the monolithic construction with integrated power switches and inclusion of all necessary circuitry yields a solution with a minimal PCB footprint. An ultralow 2.5μA quiescent current—with the output in full regulation—enables applications requiring highest efficiency at very small load currents. Its 3.4V to 42V input voltage range makes it ideal for automotive and industrial applications.

LT8640 – 42V, 5A Synchronous Step-Down Silent Switcher – [Link]

 

LT3744 – High Current Synchronous Step-Down LED Driver

3744

The LT®3744 is a fixed frequency synchronous step-down DC/DC controller designed to drive a LED load at up to 20A continuous or 40A pulsed. The peak current mode controller will maintain ±3% LED current regulation over a wide output voltage range, from VEE to VIN. By allowing VEE to float to negative voltages, several LEDs in series can be driven from a single Li-Ion battery with a simple, single step-down output stage. PWM dimming is achieved with the PWM pins. The regulated LED current is set with analog voltages at the CTRL pins. Regulated voltage and overvoltage protection are set with a voltage divider from the output to the FB pin. The switching frequency is programmable from 100kHz to 1MHz through an external resistor on the RT pin.

Additional features include an accurate external reference voltage, a control input for thermally derating regulation current, an accurate EN/UVLO pin, an open-drain output fault flag, OVLO, frequency synchronization, and thermal shutdown.

LT3744 – High Current Synchronous Step-Down LED Driver – [Link]

Five steps to a great PCB layout for a step-down converter

TPS62360

By Chris Glaser @ ti.com:

Especially for switch-mode power supplies (SMPSs), the printed circuit board (PCB) layout is a critical but often under appreciated step in achieving proper performance and reliability. Errors in the PCB layout cause a variety of misbehaviors including poor output voltage regulation, switching jitter, and even device failure. Issues like these should be avoided at all costs, since fixing them usually requires a PCB design modification. However, these pitfalls are easily circumvented if time and thought are spent during the PCB layout process before the first PCBs are ever ordered. This article presents five simple steps to ensure that your next step-down converter’s PCB layout is robust and ready for prototyping.

Five steps to a great PCB layout for a step-down converter – [Link]

Silent Switcher with high efficiency and low EMI/EMC

AppSchemx600

by Steve Taranovich @ edn.com:

Linear Technology Corporation just announced another in its series of power management ICs for automotive usage, the LT8640, a 5A, 42V input capable synchronous step-down switching regulator. A unique Silent Switcher™ architecture, combined with spread spectrum frequency modulation, reduces EMI/EMC emissions by more than 25dB even with switching frequencies in excess of 2MHz, enabling it to easily pass the automotive CISPR25, Class 5 peak limits. This feature varies the clock with a triangular frequency modulation of +20%.

Silent Switcher with high efficiency and low EMI/EMC – [Link]

Dual 3A PSU on a Chip

ISL8203M

by elektor.com:

Intersil have introduced a single chip just 9 x 6.5 mm which contains just about all the control features (including the output stages) needed to build a dual 0.8 to 5 V power supply with 3 A per channel output capability. The ISL8203M can also supply 6 A in current sharing operation.

The ISL8203M is an integrated step-down power module optimized for generating low output voltages down to 0.8V. The input supply voltage range spans from 2.85 V to 6 V. The two channels are clocked 180° out-of-phase to help reduce input RMS current and EMI. While in current sharing mode this interleaving of the two channels is beneficial for reducing input and output voltage ripple.

Dual 3A PSU on a Chip – [Link]