Tag Archives: Switchmode

Bias generators with ultralow noise and ripple for sensitive circuits


The LT®3095 generates two low-noise bias supplies from a common input voltage ranging from 3V to 20V. Each channel includes a fixed frequency, peak current-mode step-up switching regulator and a low-noise, singleresistor- programmable 50mA linear regulator. The linear regulator’s high power supply ripple rejection (PSRR) combined with its low-noise performance results in less than 100μVP-P output ripple and noise.

Bias generators with ultralow noise and ripple for sensitive circuits – [Link]

1A, 2 MHz, 60V boost/SEPIC/inverting DC/DC converter, 6µA Iq


by Graham Prophet:

LT8330 is a current mode, 2 MHz step-up DC/DC converter with an internal 1A, 60V switch. It operates from an input voltage range of 3V to 40V, making it suitable for applications with input sources ranging from a single-cell Li-Ion to automotive inputs.

The device can be configured as either a boost, SEPIC or an inverting converter. It uses a fixed 2 MHz switching frequency, enabling designers to minimise external component sizes and avoid critical frequency bands, such as AM radio. Burst Mode operation reduces quiescent current to 6 µA while keeping output ripple below 15 mVP-P. The combination of a 3 x 2 mm DFN or TSOT-23 package and tiny externals ensures a very compact footprint while minimising overall cost.

1A, 2 MHz, 60V boost/SEPIC/inverting DC/DC converter, 6µA Iq – [Link]

LTC3335 – Nanopower Buck-Boost DC/DC with Integrated Coulomb Counter


The LTC®3335 is a high efficiency, low quiescent current (680nA) buck-boost DC/DC converter with an integrated precision coulomb counter which monitors accumulated battery discharge in long life battery powered applications. The buck-boost can operate down to 1.8V on its input and provides eight pin-selectable output voltages with up to 50mA of output current.

The coulomb counter stores the accumulated battery discharge in an internal register accessible via an I2C interface. The LTC3335 features a programmable discharge alarm threshold. When the threshold is reached, an interrupt is generated at the IRQ pin.

To accommodate a wide range of battery types and sizes, the peak input current can be selected from as low as 5mA to as high as 250mA and the full-scale coulomb counter has a programmable range of 32,768:1.

LTC3335 – Nanopower Buck-Boost DC/DC with Integrated Coulomb Counter – [Link]

100V, 1A, synchronous step-down regulator: Iq of 7µA


by Graham Prophet @ edn-europe.com:

LT8631 is a 1A, 100V-input-capable synchronous step-down switching regulator. Synchronous rectification delivers efficiency as high as 90% while Burst Mode operation keeps quiescent current under 7µA in no-load standby conditions.

Its 3V to 100V input voltage range suits it for 48V automotive systems, dual battery transportation, industrial and 36V to 72V telecom applications. Its internal high efficiency switches deliver up to 1A of continuous output current to voltages as low as 0.8V. The LT8631’s Burst Mode operation offers ultralow quiescent current, suiting it for applications such as automotive “always-on” systems. The LT8631’s unique design maintains a minimum dropout voltage, enabling it to operate with duty cycles up to 99%. Its resistor-programmable 100 kHz to 1 MHz frequency range and synchronisation capability enable optimisation between efficiency and external component size. The LT8631’s 20-lead TSSOP package with high voltage lead spacing ensures a compact, thermally efficient footprint for high voltage applications.

100V, 1A, synchronous step-down regulator: Iq of 7µA – [Link]

Simplify DC-DC Converter Characterization


by Mary Anne Tupta @ edn.com:

DC-DC converters are widely used components that convert DC power from one voltage to another, producing a regulated output voltage. These devices are used in many electronic products, including laptops, mobile phones, and instrumentation. Like any device, DC-DC converters need to be characterized by manufacturers and by engineers evaluating them for a design.

Given the increased pressure to develop products that consume less power, design engineers are looking for ways to increase power conversion efficiencies. Thus, numerous measurements are required to characterize the electrical parameters of DC-DC converters.

Simplify DC-DC Converter Characterization – [Link]

60V LED Driver with Internal 4A Switch & PWM Generator


The LT3952 is a current mode step-up DC/DC converter with an internal 60 V, 4 A DMOS power switch. It is specifically designed by Linear Technology to drive high power LEDs in multiple configurations. It combines input and output current regulation loops with output voltage regulation to operate as a flexible current/voltage source. The LT3952’s 3 V to 42 V input voltage range makes it ideal for a wide variety of applications, including automotive, industrial and architectural lighting.

60V LED Driver with Internal 4A Switch & PWM Generator – [Link]

Aren’t you very satisfied with “empty” datasheets?


Top-class component should be equipped with a top class documentation. That´s also a case of many AC/DC and DC/DC modules series from Traco Power.

Demands of various application also vary. While somewhere it´s enough to know, that a given power supply will give us „some DC12V/1A“ or that a given „LED shines green and withstands 20mA“, in majority of cases we naturally need much more about a given component. Somewhere at the end of this chart are applications, where we need to know literally every parameter, including commonly non-mentioned parameters and graphs from a real measurement.

From this point of view, Swiss company Traco Power is really helpful at development and at selecting given AC/DC or DC/DC module, as all power modules are equipped with quality documentation in a form of detailed datasheets, certificates, 3D drawings and similar. Masterpiece – the application notes are available for several „high performance“ modules like for example TEN8WI module.

TEN8xxxxWI is the 8W DC/DC isolating module with a high energy density, enhanced range of operating temperatures and a wide input voltage range( 4:1). Besides a common documentation, there´s also available the TEN8WI application note, where we can find all important information for successful usage even in critical applications (EN50155-railways), including EMC characteristics, thermal consideration, recommended PCB layout and other.

For applications, where we don´t require that wide input voltage range, the standard TEN8 version (non- „WI“) is intended. In the TEN8 and TEN8WI families can be found a large amount of types with various input voltages (input 9-18VDC, 18-36, 36-75 or 9-36, 18-75 at the WI series) and 3.3 to 15Vdc output, including symmetrical ones (for example +-12V). On stock we keep a few versions, all other versions we´re able to supply you in a short leadtime.

Detailed information will provide you datasheets at particular types, as well as above-mentioned TEN8WI application note, TEN8WI certificate, TEN8WI-3D drawing and the TEN8 series filter design.

Aren’t you very satisfied with “empty” datasheets? – [Link]

LTC3892/LTC3892-1 – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller


The LTC®3892/LTC3892-1 is a high performance dual step-down DC/DC switching regulator controller that drives all N-channel synchronous power MOSFET stages. Power loss and noise are minimized by operating the two controller output stages out-of-phase.

The gate drive voltage can be programmed from 5V to 10V to allow the use of logic or standard-level FETs and to maximize efficiency. Internal switches in the top gate drivers eliminate the need for external bootstrap diodes.

LTC3892/LTC3892-1 – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller – [Link]

AppNote: Inverting DC/DC controller converts a positive input to a negative output with a single inductor


by DAVID BURGOON @ edn.com:

There are several ways to produce a negative voltage from a positive voltage source, including using a transformer or two inductors and/or multiple switches. However, none are as easy as using the LTC3863, which is elegant in its simplicity, has superior efficiency at light loads and reduces parts count compared to alternative solutions.

The LTC3863 can produce a –0.4V to –150V negative output voltage from a positive input range of 3.5V to 60V. It uses a single-inductor topology with one active P-channel MOSFET switch and one diode. The high level of integration yields a simple, low parts-count solution.

AppNote: Inverting DC/DC controller converts a positive input to a negative output with a single inductor – [Link]

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


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]