Tag Archives: DC-DC

1A from the sugar cube sized module


With continuous improvement TRACO unveils the SMD version of enormously successful 1A DC/DC converter, the TSR1SM.

The TSR1SM series models of step-down switching regulators (non isolating – POL) have a high efficiency up to 96 % which allows full load operation up to +65°C ambient temperature without the need of any heat transmission layer. Excellent output voltage accuracy (±2%) and low standby current (~1 μA) are features that distinguish these switching regulators from linear regulators.To make a SMD version of such a DC/DC converter is not a simple task, the package should withstand temperatures up to 245°C, used in a lead free soldering ovens. TRACO solved successfully this problem and the TSR1SM is qualified for lead free soldering processes as per J-STD-020D.01 (to find at: www.jedec.org – free registration required) with max. peak body temperature 245°C. Also low MSL level 1 allows PCB washing after soldering with baking at 100°C for 30min.

For applications which require lower supply currents up to 0,5Amps, there is a TSR0,5(SM)series of DC/DC converters with better price level available.

1A from the sugar cube sized module – [Link]

MC34VR500V1ES Multi-Output DC/DC Regulator

The circuit in this reference design features the capability of MC34VR500V1ES to supply multiple DC voltage outputs. This device is designed to support the LS1/T1 family of communication processors, which require efficient and precise level of voltage supplies. With its four switching and five linear regulators, the MC34VR500V1ES can supply power to the whole system, e.g., the processor, memory, system peripherals.

The MC34VR500V1ES device runs with a supply voltage ranging from 2.8V to 4.5V. It can provide nine outputs. Four of these outputs (SW1-4) are buck regulators while the rest (LDO1-5) are general purpose LDOs. Each one of the buck regulator is capable of operating in Pulse Frequency Modulation (PFM), Auto Pulse Skip (APS), and Pulse Width Modulation (PWM) switching modes. These buck regulators also have a current limit feature that generates a fault interrupt whenever there is an overcurrent condition. The SW1 output is capable of providing 0.625-1.875V/4.5A supply while SW2 and SW3 can provide 0.625-1.975V/2A and 0.625-1.975V/2.5A, respectively. The SW1, SW2 and SW3 voltages can be varied with a step size of 25mV. The SW4 output is half of the voltage output of SW3. The general output LDOs can output voltages ranging from 1.8-3.3V with a step size of 100mV except for LDO1 which can only give 0.8-1.55V output with 50mV step size. The LDO1 output can provide current up to 250mA, while LDO2 and LDO4 can output up to 100mA only. The LDO5 output can provide 200mA of current while LDO3 can output up to 350mA. Aside from these nine outputs, the MC34VR500V1ES also have a REFOUT output dedicated for DDR memory reference voltage. The voltage of this REFOUT output is usually half of the SW3 output and can only provide up to 10mA of current. The MC34VR500V1ES outputs can be changed by programming it via the I2C interface.

The operation of the MC34VR500V1ES can be reduced to four states, or modes: ON, OFF, Sleep, and Standby. For the device to turn ON, the input voltage must surpass a voltage threshold of 3.1V, the EN pin must be high, and PORB is de-asserted. The 34VR500 enters the OFF mode when the EN pin is low or there is a thermal shutdown event that forces the device into the OFF mode. Standby mode is usually entered when the STBY pin is asserted for low-power mode of operation. The device only goes into sleep mode if the EN pin is de-asserted. To exit sleep mode, assert the EN pin.

MC34VR500V1ES Multi-Output DC/DC Regulator – [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]

LM2596 DC-DC Converter Module Testing


by Kerry D. Wong:

LM2596 based step-down DC-DC converter modules can be bought on eBay quite cheaply for around a dollar each. But how do they perform? Is it safe to use it to power your design? Let’s find out.

According to TI’s website, these LM2596 step-down (buck) regulators are sold for $1.8 each for a quantity of a thousand. So how a finished converter could be sold for just above a dollar each is quite a mystery to me. Anyway, the picture below is the board I received. It appears that there are a few variations to this design (slightly different inductor size or capacitor size/voltage rating, etc.) but they all are largely based on the reference design.

LM2596 DC-DC Converter Module Testing – [Link]

Buck converter is pin-programmable


by Susan Nordyk @ edn.com:

Housed in a tiny 3×3-mm QFN package, the MIC24046-H synchronous step-down regulator from Micrel offers efficiency of greater than 90% peak and pin-selectable output voltage, switching frequency, and current limit. A wide input voltage range of 4.5 V to 19 V makes the part useful for distributed 12-V point-of-load applications.

The switching frequency of the MIC24046-H can be programmed to one of three options: 400 kHz, 565 kHz, or 790 kHz. Programmable output-voltage choices include 0.7 V, 0.8 V, 0.9 V, 1.0 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, and 3.3 V, while an internal divider is used to achieve ±1% voltage-output accuracy. The current limit of the regulator can be programmed to 3 A, 4 A, or 5 A.

Buck converter is pin-programmable – [Link]

2A, 70V SEPIC/Boost DC/DC converter with 7µA Iq


by Graham Prophet @ edn-europe.com:

LT8494 is a current mode, fixed frequency SEPIC/boost DC/DC converter with an internal 2A, 70V switch. Quiescent current of 7µA suits the device for always-on automotive or other industrial battery powered systems.

The LT8494 starts up from an input voltage range of 2.5V to 32V and once running it operates from inputs from 1V to 60V, making it suitable for applications with input sources ranging from a single-cell Li-Ion to automotive inputs. The LT8494 can be configured as a boost, SEPIC or flyback converter. Its switching frequency can be programmed via a single resistor to between 250 kHz and 1.5 MHz, enabling designers to minimise external component sizes. The combination of a thermally enhanced TSSOP-20E or 4 x 4 mm QFN package and small externals ensures a very compact footprint.

2A, 70V SEPIC/Boost DC/DC converter with 7µA Iq – [Link]

A low-cost 0.5A 33V LED driver module with 90+% efficiency

LG-LED-150702-DF-Futuro Low-cost LED driver Design FigA

by Valentin Kulikov @ edn.com

This article describes simple constant current driver module with fast PWM input that can be used for driving medium and high power LEDs. The module uses an integrated constant-current output, DC-DC buck converter with output current configurable from 0.1 to 0.5A. This article outlines the schematic, design guidelines, operation, and performance of the low cost LED driver.

A low-cost 0.5A 33V LED driver module with 90+% efficiency – [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]