Chip Marries 60 V Buck Controller and 4 Buck Regulators

Analog Devices has announced the Power by Linear LTC3372, an integrated power management solution for systems that require multiple low voltage outputs generated from an input voltage as high as 60 V. The LTC3372 features a 60 V synchronous buck switching regulator controller followed by four configurable synchronous monolithic buck regulators. This combination provides up to five high efficiency low quiescent current outputs in a single IC, well-suited for automotive, industrial and medical applications.

The LTC3372’s buck controller operates over a 4.5 V to 60 V input voltage range and drives an all N-channel MOSFET power stage. Its output can be programmed to either 3.3 V or 5 V and can generate an output current up to 20 A. The controller output is typically used to feed the four monolithic buck regulators. Each monolithic buck channel can be programmed to regulate an output voltage as low as 0.8 V with a configurable output current up to 4 A. Eight 1 A integrated power stages are programmed by the C1-C3 pins into one of eight unique configurations, from a quad 2 A buck to a dual 4 A buck. This allows only one inductor per channel.

The LTC3372 offers a low IQ solution ideal for battery-powered or automotive applications in which one or more power supply rails are always on. With just the high voltage controller enabled, the device draws 15 µA from a 12 V input supply while regulating the output to 5 V at no load. Each monolithic buck regulator adds only 8 µA of additional IQ per channel enabled. The LTC3372’s monolithic buck switching frequency can be programmed from 1 MHz to 3 MHz and can be synchronized to an external clock while the buck controller switches at 1/6 of this frequency. Additional features include foldback current limiting, soft-start, short-circuit protection and output overvoltage protection.

The LTC3372 is available from stock in a thermally enhanced 48-pin 7 mm × 7 mm QFN package. E and I grades are specified over an operating junction temperature range of –40°C to 125°C, and the H grade features operation from –40°C to 150°C.

Analog Devices | www.analog.com

Power Switching Regulator Has Boost and 3x Buck Capabilities

Analog Devices has announced the Power by Linear LT8603, a 42 V input capable, high efficiency quad output monolithic switching regulator. Its flexible design combines a boost controller with two high voltage 2.5 A and 1.5 A synchronous step-down channels and a lower voltage 1.8 A synchronous step-down channel to provide four independent outputs. The LT8603 can be configured with the boost controller to supply the input of the buck converters, enabling it to deliver three precisely regulated outputs. Alternatively, the boost controller can be driven from one of the step-down outputs, providing four precisely regulated outputs with a very compact solution footprint.

The LT8603’s triple buck synchronous rectification topology delivers up to 93% efficiency while Burst Mode operation keeps quiescent current under 28 µA (high voltage channels active) in no-load standby conditions, ideal for always-on systems. For noise-sensitive applications, the LT8603’s low EMI design meets the CISPR 25, Class 5 EMI requirements even when switching at 2 MHz. The LT8603’s switching frequency can be programmed from 250 kHz to 2.2 MHz and is synchronizable throughout this range.

The LT8603’s 85 ns (max) minimum on-time and cascading topology enables 16VIN to 0.8VOUT step-down conversions while switching at 2 MHz, enabling designers to avoid critical noise-sensitive frequency bands such as AM radio, while using a very compact solution footprint. Its 3 V to 42 V input voltage range is ideal for automotive applications that must regulate through cold crank and stop-start scenarios with minimum input voltages as low as 3V and load dump transients in excess of 40 V. Programmable power-on reset and power good indicators for each channel ensure overall system reliability. The LT8603’s 40-lead thermally enhanced 6 mm x 6 mm QFN package and high switching frequency keep external inductors and capacitors small, providing a compact, thermally efficient footprint.

The LT8603 is available in a thermally enhanced 40-lead 6 mm x  6 mm QFN package. Two temperature grades are available, with operation from -40°C to 125°C (junction) for the extended E- and industrial I-grades.

Analog Devices | www.analog.com

24 V Buck Regulator Boasts 20 A Output

Vicor has announced a 20 A version of its Cool-Power ZVS Buck, PI3325-00-LGIZ. It represents the highest current output ZVS buck to date for 24 V / 28 V applications, providing a regulated 5 V output at up to 20 A. Packaged within a 10 mm x 14 mm x 2.5 mm LGA SiP package, the PI3325-00-LGIZ addresses the continued need for high power density across a growing spectrum of applications. It also offers pin-for-pin compatibility to a 48V input version ZVS buck, the PI3525-00-LGIZ, enabling designs to be quickly ported from 24 VIN capability to 48 VIN.

The PI3325-00-LGIZ requires only an output inductor and minimal passives for a complete, cost-effective, compact design that consumes less than 740 mm2 of PCB real estate. Higher current is also achievable by parallel operation of the regulator. The PI3325-00-LGIZ represents one regulator within a new portfolio of higher current 24V ZVS bucks already or soon to be released.

According to Vicor, Cool-Power ZVS regulators deliver more power at higher temperatures than competitive devices, without sacrificing power density or efficiency. Key attributes to the Cool-Power ZVS regulators’ high performance include zero-voltage switching topology, high silicon integration, and high density LGA SiP packaging. These high performance regulators are also simple to use.

Vicor | www.vicorpower.com

New Synchronous Buck Regulators Offer POL Conversions

Intersil Corp. recently announced a new  family of monolithic synchronous buck regulators that step-down 5- and 3.3-V primary rails to point-of-load (POL) inputs as low as 0.6 V for GPUs, DSPs, SoCs,and FPGAs. The pin-compatible ISL78233, ISL78234, and ISL78235 deliver 3, 4, and 5 A, respectively, of continuous output current to infotainment head units and advanced driver assistance systems (ADAS). intersil isl7823

Using a current mode control architecture to deliver fast transient response and excellent loop stability, the ISL7823x synchronous step-down DC/DC converters integrate low RDSon high-side PMOS and low-side NMOS MOSFETs. Moreover,  they combine a switching frequency of 2 MHz with guaranteed 100 ns (max) minimum on time to avoid AM radio channel interference.

ISL7823x features and specifications:

  • Support input voltage range from 2.7 to 5.5 V and deliver high efficiency up to 95%
  • 100 ns guaranteed phase minimum on time for wide output regulation
  • Adjustable switching frequency from 500 kHz to 4MHz (with 2 MHz default)
  • External synchronization up to 4 MHz
  • Provide 1% reference accuracy for tight regulation
  • Soft-stop output discharge during disable
  • Fault protections  (over-temperature, over-current, output over-and under-voltage, input under-voltage lockout, short-circuit, and negative over-current)
  • AEC-Q100 qualified for operation from –40°C to 125°C
  • Wettable flank QFN package

The ISL78235 5-A synchronous buck regulator is available in a 5 mm × 5 mm 16-lead WFQFN package for $2.75 in 1,00-unit quantities. A 3 mm × 3 mm TQFN package is also available. The ISL78235EVAL2Z evaluation board costs $67.80.

The ISL78233 3-A and ISL78234 4-A synchronous buck regulators are available now in 5 mm × 5 mm 16-lead WFQFN packages. The ISL78233 costs $1.75 in 1,000-unit quantities. The ISL78234 is $1.95 in 1,000-unit quantities. The ISL78233EVAL2Z and ISL78234EVAL2Z evaluation boards cost $56 each.

Source: Intersil Corp.

High Efficiency, Highly Integrated 8A and 3A Synchronous Buck Regulators

Intersil Corp. recently announced five new highly integrated synchronous buck regulators that step-down 5-V rails to point-of-load (POL) inputs as low as 0.6 V for FPGAs, DSPs, and microprocessors. The ISL8018 delivers up to 8 A of continuous output current from a 2.7-to-5.5-V input supply. In addition, it provides up to 97% efficiency and higher integration than similar devices.

The ISL8003x devices deliver up to 3 A of continuous output current from a 2.7-to-5.5-V input supply and offer up to 95% peak efficiency for delivering general POL conversions. Useful in telecom, cloud computing, industrial, and medical equipment, the ISL8018 provides an innovative SYNCIN and SYNCOUT feature that connects and synchronizes multiple regulators at the same switching frequency in a master/slave configuration using a phase shifting time delay. With the ISL8018’s VSET feature, the voltage output margining can be set at 10% to compensate for output voltage IR drop. The ISET feature provides programmable output current limits to support 8-, 5-, and 3-A applications. This allows customers to leverage one design with smaller inductors for reduced costs and board area. In addition, the ISL8018’s programmable switching frequency from 500 kHz up to 4 MHz enables the use of smaller passive components for faster transient response and further board space savings.

Key features and specifications:

  • High peak efficiency up to 97%
  • Converter occupies less than 97 mm2 of board space
  • ±10% output voltage margining
  • Output voltage is adjustable from 0.6 V to Vin, with a fixed output voltage option
  • External synchronization up to 4MHz, with master-to-slave phase shifting capability
  • Adjustable switching frequency from 500 kHz to 4 MHz, with default at 1 MHz
  • Start-up with pre-bias output, internal soft-start—1 ms or adjustable, internal/external compensation
  • Soft-stop output discharge during disabled
  • Peak current limiting, hiccup mode short circuit protection, and over-temperature protection
  • Adjustable current limit

The ISL8018 8A synchronous buck regulator is available in a 3 mm × 4 mm, 20-lead QFN package and it costs $1.60 in 1,000-piece quantities. The ISL8018DEMO1Z demonstration board costs $20. The full-featured ISL8018EVAL3Z evaluation board is $115.

Source: Intersil Corp.

Ultra-Low Power Buck Regulator Extends Battery Life

Analog Devices recently launched an ultralow power buck regulator that extends battery life in portable devices by achieving high ultra-light-load power conversion efficiency. With a 90% efficiency rating and consuming only 180-nA quiescent current, the ADP5301 buck regulator provides maximum power for a longer period of time than previously achievable. The regulator’s tiny WLCSP package measures less than 3.1-mm², which makes it suitable for small form factors.

A great solution for Internet of Things (IoT) applications, the ADP5301 has several key features:

  • 90% power conversion efficiency in ultralight load with 180-nA quiescent current boosts battery life
  • 6.5- to 2.05-V input voltage range enables several battery sources or architectures
  • Selectable, low-noise forced PWM mode with low output voltage ripple powers noise-sensitive analog load up to 500-mA output current capability
  • Integrated voltage supervisory function increases overall system reliability

Source: Analog Devices