by Susan Nordyk:
The LT8471, a dual PWM DC/DC converter from Linear Technology, employs two internal 2-A, 50-V switches and an additional 500-mA switch to facilitate step-down, step-up, and inverting conversions. Each 2-A channel can be independently configured as a buck, boost, SEPIC, flyback, Zeta, or inverting converter.
This broad range of topologies and output configurations makes the LT8471 useful for a wide range of industrial and automotive applications. The converter operates from an input voltage of 2.6 V to 50 V, allowing it to be used with input sources ranging from single-cell lithium-ion to automotive batteries.
The LT8471 is capable of generating both positive and negative outputs. Its switching frequency is programmable and synchronizable from 100 kHz to 2 MHz. The device’s 50-V switches achieve overall efficiencies of up to 85% for buck and inverting applications. Operating from a 6-V to 32-V input, the LT8471 delivers up to 1.5 A at 5 V and 650 mA at –5 V.
Housed in a 20-lead, thermally enhanced TSSOP, the LT8471 costs $3.75 each in lots of 1000 units. An industrial-temperature version is priced at $4.13 in like quantities. Both versions are available from stock.
Multiple-topology DC/DC converter integrates dual 2-A switches - [Link]
by Mary Anne Tupta:
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]
by Zhongming Ye:
Flyback converters are widely used in isolated DC/DC applications because of their relative simplicity and low cost compared to alternative isolated topologies. Even so, designing a traditional flyback is not easy—the transformer requires careful design, and loop compensation is complicated by the well known right-half plane (RHP) zero and the propagation delay of the opto-coupler.
Linear Technology’s no-opto flyback converters, such as the LT3573, LT3574, LT3575, LT3511, and LT3512, simplify the design of flyback converters by incorporating a primary-side sensing scheme and running the converter in boundary mode.
Micropower Isolated Flyback Converter with Input Voltage Range from 6V to 100V - [Link]
Nixie tubes need about ~180Vdc to light up and thus on most devices a DC-DC converter is needed. We designed here a simple DC-DC switching regulator capable of powering most of Nixie tubes.
The module is based on the MAX1771 Step-Up DC-DC Controller. This controller works up to 300kHz switching frequency and that allows the usage of miniature surface mount components. It accepts an input voltage from 2 to 16.5V and the output is factory configured to 12V. In this module the output voltage is configured higher at ~180Vdc using external resistors and a potentiometer.
HV Nixie DC-DC Power Supply - [Link]
TOREX SEMICONDUCTOR (Tokyo, Japan) has introduced the XCL101 series of micro DC/DC converters. The tiny CL-2025 package outline measures just 2.5 mm x 2.0 mm x1.0 mm and is the first step-up type converter in the XCL series of micro DC/DCs with integrated coil.
The only external components necessary for most applications are just two ceramic capacitors. Output voltage is predefined by an internal voltage divider network so 33 variants of the chip cover the complete output range from 1.8 V to 5.0 V in 0.1 V steps. The chip can supply a maximum output current of 100 mA and has a maximum power dissipation of 1 W. Its a no-load quiescent current is 6.3 μA
Tiny DC-DC converter with integrated coil - [Link]
The LTM4644 is a quad DC/DC step-down μModule (micromodule) regulator with 4A per output. Outputs can be paralleled in an array for up to 16A capability. Included in the package are the switching controllers, power FETs, inductors and support components – only bulk input and output capacitors are needed. Operating over an input voltage range of 4V to 14V or 2.375V to 14V with an external bias supply, the LTM4644 supports an output voltage range of 0.6V to 5.5V each set by a single external resistor. The LTM4644 is offered in 9mm ×15mm × 5.01mm BGA package.
LTM4644 – quad DC/DC step-down μModule regulator with 4A per output - [Link]
Modern DC/DC controllers from company Infineon, like TLF51801ELV manage even big challenges.
Perhaps everyone knows, that modern switch-mode power supplies are able to efficiently convert voltage and to replace linear power supplies. Features of ready-made DC/DC modules as well as SMPS controllers themselves are still better and nowadays it´s no problem to construct a 10A power supply on a small area. It is necessary to say, that for the most of applications it´s more advisable to use a ready-made module with proven features, developed by specialists in a given segments, like for example modules from company Traco. Despite this, there are surely many applications, where from several reasons it´s beneficial to use an own design. Offer of controllers for switch-mode power supplies is wide and this time we´d like to introduce you a modern step-down (buck) controller TLF51801ELV from company Infineon.
TLF51801 is interesting mainly by its overall „robustness“, because it´s directly designed for a construction of power supplies with a high output current (up to approx. 10A), what is also reflected in the MosFET drivers sizing, integrated soft start, under- and over-voltage protection, temperature protection, possibility of current limit setting and another features. Very beneficial is also a duty cycle of up to 99% enabling operation with a minimum difference (dropout) between input and output voltage.
TLF51801 is designed as a controller with a voltage feedback requiring 2 external N-FET transistors sized for a desired output current. Current monitoring (via pins SenseLow+SenseHigh) can be done through external sensing (shunt) resistor or with an advantage of a higher overall efficiency even an internal resistance of an FET transistor (RDSon). TLF5180 can operate in a wide range of input voltages 4,75-45V and at frequencies of 100-700kHz, while the clock frequency can be synchronized to an external clock. The circuit can be easily switched off via the “En” pin (enable), when it consumes only 2uA. An integrated thermal protection switches off the circuit at exceeding 175°C and switches on again (+SoftStart) after cooling down to 160°C.
The circuit TLF51801ELV is a brand new type and it will be soon available upon order. Detailed information will provide you the TLF51801ELV datasheet.
10A with 96% efficiency … no problem for TLF51801 - [Link]
International Rectifier’s IR3846 is a member of the Gen3 SupIRBuck family of highly integrated synchronous voltage regulators. IR3846 is a compact DC-DC regulator with a single input supply without the need of an external VCC with its internal LDO and has a high current output of up to 35 A. Being part of the Gen3 SupIRBuck family, it has a corrective and unique modulation feature that gives a jitter-free and noise-free operation allowing higher frequency and higher bandwidth operation for better transient response. The device is very efficient and ideal for power applications of enterprises requiring space such as netcom server/storage, distributed point-of-load power architecture, and embedded telecom systems that involve high power density.
With a market price of $29, IRDC3846 evaluation board is highly efficient and cost-effective having multiple features. The PCB is a 200 mm^2, 6-layer board mounted with few passive components. Some of the important features of the board include: digital soft-start up, power good operation, overvoltage protection, thermal shutdown, and programmable switching frequency, which is flexible for different applications ranging from 300 kHz-1.5 Mhz. It is designed to a well-regulated input supply of +12V and configured for remote differential sensing.
The IRDC3846 evaluation board is very easy-to-use. Simply connect a +12V input supply at VIN+ and VIN- and a maximum of 35 A load should be connected to VOUT+ and VOUT-. If external VCC is required in an operation, Vin and VCC pins should be shorted together by installing a 0 ohm resistor. Other than remote sensing, the board can also be configured for local sensing by changing the resistors needed for operation. The length of the on-board power ground is minimized for better efficiency. Using separate power ground and analog ground, both can be connected together using a 0 Ohm resistor.
If you need a low voltage, high current regulator, IR3846 definitely should be considered. Having a small footprint, the device has exceptional capability offering high density. It is likely suitable for many applications in network communication and storage systems.
International Rectifier SupIRBuckTM IRDC3846 Evaluation - [Link]
Charge pump ICs offer high-efficiency DC-DC conversion and have a tiny footprint. They offer step-up or inverting conversion for applications with generally low-output current requirements.
New 6W DC/DC module series TEN5 won´t be scared neither of a very fluctuating input voltage, that´s why it´s ideal even for battery-operated applications.
Series TEN5 is a well proven reliable series of insulating DC/DC modules with a fixed output voltage, in case of TEN5-2411WI it is 5V. TEN5 series is available in so to say “basic” version with a 2:1 input voltage range and also in this „WI – wide input“ version, with a 4:1 ratio. In the most of cases, it´s probably possible to choose an appropriate type, for example TEN5-1211 with an input voltage of 9-18V, which is for example ideal for 12V applications with Pb accumulators (SLA). However namely for the mobile applications it can be beneficial, if a given device could be powered also by for example 24V, used in cargo trucks.
TEN5-2411WI with an input voltage of 9-36V and 5V/1A output is suitable this new type from our stock offer. Besides mentioned wide range of input voltages it also features a good efficiency (79% typ.) and excellent regulation at a change of input and/or load. Enhanced operating temperatures range (-40 to +85°C) and resistance to a continuous shortcut make it suitable even for demanding applications. Also useful is the built-in filter to meet EN55022 Class A and FCC level A. Metal shielded package in a standard DIP-24 package with an insulated base plate simplifies PCB design and also assembly to a PCB. In the TEN5 series can be found 2 versions: with input voltages of 9-36V or 18-75VDC with various output voltages, including symmetrical ones.
Detailed information can be found in the TEN5-WI datasheet.
TEN5-2411WI – don´t be limited by an input voltage - [Link]