DC-DC converters

Haiben is a Shenzhen electronic components supplier founded in 2013, serving purchasing teams and hardware engineers at electronics manufacturers. Alongside our catalogue of power ICs and memory, we operate the Weforsemi line through our wholly-owned subsidiary, which covers DC-DC boost ICs, DC-DC buck ICs, charging ICs, LDOs and LED drivers. This page explains how the main converter topologies map to common rails, and how to specify a dc dc converter before requesting a quotation.

The three topologies and the rails they serve

A dc dc converter takes a DC input and produces a regulated DC output, either stepping the voltage down, up, or across the input value. The choice of topology follows the rail, not the other way round. In most electronic products the available input is a battery or an adapter rail, while the loads are logic cores, analogue supplies, interface rails, displays or LEDs. Each of these has a voltage window that the converter must respect under load and across temperature. The three families below cover the majority of those requirements, and Haiben's catalogue organises them as Buck DC/DC Converters / Step-Down, Boost DC/DC Converters / Step-Up, and the crossover parts grouped with the buck-boost family.

Each topology has a characteristic set of trade-offs. Buck converters suit rails below the input; boost converters suit rails above it; buck-boost devices hold regulation when the input wanders above and below the output. The sections below look at each in turn.

Buck: stepping down

A buck converter switches an inductor between the input and ground, then filters the result, so the output voltage is a fraction of the input set by the duty cycle. It is the usual choice when a higher input, such as a 12 V or 24 V bus or a multi-cell battery pack, must feed logic or analogue circuitry at a lower voltage. Because the inductor carries the load current continuously, a buck stage typically delivers higher efficiency than a linear regulator at the same step-down ratio, at the cost of switching noise and a more involved layout.

For buyers and engineers selecting from our catalogue, our buck converters are organised under the Buck DC/DC Converters / Step-Down category. The specification method is the same for any buck design: define the input voltage range including transients, the output voltage and its tolerance, the maximum and typical load current, the acceptable ripple, the switching frequency or frequency band, and the thermal and package constraints of the board. Exact part numbers, input-voltage ranges, current ratings and datasheet values for the Weforsemi buck ICs are confirmed at quotation, so the purchasing team should treat catalogue entries as a starting point for the RFQ rather than as a final specification.

Boost and buck-boost: stepping up and crossing over

A boost converter stores energy in an inductor while the switch is on and delivers it to the output when the switch turns off, so the output sits above the input. Typical uses include generating a higher bias rail from a lower battery or adapter voltage, driving LED strings whose forward voltage exceeds the supply, and producing local rails in instruments. Boost stages have a right-half-plane zero in their control loop, which makes compensation more demanding than in a buck design, so the datasheet's recommended component values and layout guidance carry real weight.

Our boost converters sit under the Boost DC/DC Converters / Step-Up category. A buck-boost converter, by contrast, regulates through the crossover point where the input may be above, below or equal to the output. This is the right family for battery-powered equipment whose pack voltage falls through the rail voltage during discharge, and for supplies that must hold a stable output from an adapter that sags under load. Our buck-boost converters are specified in the same way: input range, output voltage, load current, ripple, switching frequency, and the operating mode required at the crossover. As with the buck family, model-level data is confirmed at quotation.

Two further catalogue categories support these rails. Low-Dropout Regulators (LDO) and Three-Terminal Voltage Regulators provide post-regulation or low-noise analogue rails where the step-down ratio is small, while Overvoltage Protection ICs (OVP) guard a rail against transients. The published OVP example in our brief set, VCP14C13P-A, is an overvoltage protection IC in a SOT23-3 package, rated in the 1.3 A class.

Specifying a converter IC for your rail

A workable specification starts with the rail, not the part. Define the following before approaching a supplier:

• Input source and its full voltage range, including startup, transient and end-of-discharge conditions.
• Output voltage, tolerance and the load steps the rail must survive.
• Maximum, typical and standby load currents, and the efficiency target at each.
• Ripple and noise limits, especially where the rail feeds analogue or RF circuitry.
• Switching frequency constraints relating to EMI, board area and inductor size.
• Package, thermal path and any qualification requirements specific to your product.

The Weforsemi line covers charging ICs, LDOs, DC-DC boost ICs, DC-DC buck ICs, backlight driver ICs and LED driver ICs. For every one of these, exact part numbers and datasheet values are confirmed at quotation; we do not publish unverified figures. Purchasing staff can send the rail specification above and receive a matched proposal, with samples and documentation agreed at the same stage. Our catalogue also includes Lithium Battery Charging ICs and a Serial Flash IC on its own page, for designs that need those functions alongside the dc dc converter.

Frequently asked questions

Can Haiben supply both the converter and the passive components around it?

Our catalogue is focused on the ICs listed on this site, including the Weforsemi line of buck, boost, LDO, charging and LED driver devices. External inductors, capacitors and resistors are selected against the datasheet of the chosen IC; the required values are confirmed with the quotation so your team can specify them correctly.

How do I choose between a buck and an LDO for a small step-down?

An LDO is simpler and quieter but dissipates the voltage difference as heat, so it suits small step-down ratios and light loads. A buck dc dc converter is more efficient at larger ratios and higher currents, at the cost of switching noise and a more careful layout. Define your load current and thermal budget first, then compare.

Are the published figures for the VCP14C13P-A the only model-level data available?

The brief set publishes the VCP14C13P-A as an overvoltage protection IC in a SOT23-3 package, rated in the 1.3 A class. For all other parts, including the Weforsemi dc dc converter ICs, model-level specifications are confirmed at quotation rather than published here.