3.3V, 2.5A Step-Up/Step-Down Voltage Regulator S13V25F3

The S13V25Fx family of efficient switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) use a buck-boost topology to convert both higher and lower input voltages to a regulated output voltage. They take input voltages from 2.8 V to 22 V and increase or decrease them as necessary, offering a typical efficiency of over 85% and typical continuous output currents between 1 A and 3 A. The flexibility in input voltage offered by this family of regulators is especially well-suited for battery-powered applications in which the battery voltage begins above the regulated voltage and drops below as the battery discharges. Without the typical restriction on the battery voltage staying above the required voltage throughout its life, new battery packs and form factors can be considered.

The S13V25Fx regulators have under-voltage lockout, output over-voltage protection, over-current protection, and reverse-voltage protection up to 20 V. A thermal shutdown feature also helps prevent damage from overheating and a soft-start feature limits the inrush current and gradually ramps the output voltage on startup.

This family consists of six 2.5 A regulators with output voltages ranging from 3.3 V to 15 V. These all use the same PCB with different components populated to achieve the different output voltages:

• S13V25F3: 3.3V output with 2.5 A continuous output current
• S13V25F6: 6V output with 2.5 A continuous output current
• S13V25F7: 7.5V output with 2.5 A continuous output current
• S13V25F9: 9V output with 2.5 A continuous output current
• S13V25F12: 12V output with 2.5 A continuous output current
• S13V25F15: 15V output with 2.5 A continuous output current

The different versions of the S13V25Fx regulators all look very similar, so the bottom silkscreen includes a blank space where you can add your own distinguishing marks or labels.

Pololu manufacture these boards in-house at Pololu's Las Vegas facility, which gives Pololu the flexibility to make these regulators with custom fixed output voltages. If you are interested in customization, please contact us.

The extended S13VxFx family also includes several 5V versions

S13VxF5 family of step-up/step-down voltage regulators.

The pin-compatible S13V30F5 outputs 5 V at up to 3 A continuous and has the same overall board dimensions as the S13V25Fx units, but please note that the tall components (i.e. electrolytic capacitors and inductor) are in different locations:

• S13V30F5: 5V output with 3 A continuous output current

Pololu also have three extra-compact 5V versions available with lower maximum output currents:

• S13V10F5: 5V output with 1 A continuous output current
• S13V15F5: 5V output with 1.5 A continuous output current
• S13V20F5: 5V output with 2 A continuous output current

Details for item #4980

3.3V Step-Up/Step-Down Voltage Regulator S13V25F3, top view.

Features

• Input voltage: 2.8 V to 22 V
• Output voltage: 3.3 V with 4% accuracy
• Typical maximum continuous output current: 2.5 A to 3.5 A, depending on input voltage (see the maximum continuous output current graph below)
• Typical efficiency of 85% to 95%, depending on input voltage and load (see the efficiency graph below)
• 10 mA to 20 mA typical no-load quiescent current (see the quiescent current graph below); can be reduced to 2 µA to 10 µA per volt on VIN by disabling the board
• Input under-voltage lockout and output over-voltage protection
• Soft-start feature limits inrush current and gradually ramps output voltage
• Integrated reverse-voltage protection up to 20 V, over-current protection, and over-temperature shutoff
• 5.1 A output current limit
• Fixed switching frequency of ~500 kHz
• Compact size: 0.9" × 0.9" × 0.38" (22.9 mm × 22.9 mm × 9.7 mm); see the dimension diagram (703k pdf) for more information
• Two 0.086" mounting holes for #2 or M2 screws

Connections

The step-up/step-down regulator has four connections: enable (EN), the input voltage (VIN), ground (GND), and the output voltage (VOUT). The input voltage, VIN, powers the regulator. Voltages between 2.8 V and 22 V can be applied to VIN. VOUT is the regulated output voltage.

The regulator, which is enabled by default, can be put into a low-power sleep state by bringing the EN pin low. The rising threshold for the EN pin is between 1 V and 1.2 V, and the typical falling threshold is 100 mV lower than that (i.e. the typical falling hysteresis is 100 mV). This allows a precise low-VIN cutoff to be set, such as with the output of an external voltage divider powered by VIN, which can be useful for battery powered applications where draining the battery below a particular voltage threshold could permanently damage it. The quiescent current draw in sleep mode is dominated by the current in the 475 kO pull-up resistor from ENABLE to VIN and in the reverse-voltage protection circuit, which altogether will be between 2 µA and 10 µA per volt on VIN.

The regulator has two sets of through-holes: five smaller holes arranged with a 0.1" spacing along the edge of the board (for compatibility with standard solderless breadboards and perfboards and connectors that use a 0.1" grid) and four larger holes intended for 3.5 mm-pitch terminal blocks. VIN, GND, and VOUT are available at both the smaller holes and larger holes, but EN is only available on the smaller row of through-holes.

Step-Up/Step-Down Voltage Regulator S13V25Fx with included hardware.

The regulator includes a 5×1 straight male header strip and two 2-pin, 3.5 mm-pitch terminal blocks, and it can be assembled with either the header or terminal blocks, not both. The 0.1" male header can be soldered into the smaller through-holes. Alternatively, the terminal blocks can be locked together and soldered into the larger holes to allow for convenient temporary connections of unterminated wires (see Pololu's short video on terminal block installation). You can also solder wires directly to the board for the most compact installation.

Step-Up/Step-Down Voltage Regulator S13V25Fx on a breadboard.

Step-Up/Step-Down Voltage Regulator S13V25Fx with terminal blocks installed.

If the terminal blocks are used, a small wire (not included) can be soldered to the enable pin as shown below, so it will not interfere with the VIN terminal block connection.

Step-Up/Step-Down Voltage Regulator S13V25Fx with terminal blocks and EN wire installed.

Step-Up/Step-Down Voltage Regulator S13V25Fx, using all five connections with terminal blocks installed.

Typical efficiency

The efficiency of a voltage regulator, defined as (Power out)/(Power in), is an important measure of its performance, especially when battery life or heat are concerns.

Maximum continuous output current

The maximum achievable output current of the regulator varies with the input voltage but also depends on other factors, including the ambient temperature, air flow, and heat sinking. The graph below shows maximum output currents that the regulators in the S13V25Fx family can deliver continuously at room temperature in still air and without additional heat sinking.

During normal operation, this product can get hot enough to burn you. Take care when handling this product or other components connected to it.

Quiescent current

The quiescent current is the current the regulator uses just to power itself, and the graph below shows this as a function of the input voltage. The module’s EN input can be driven low to put the board into a low-power state where it typically draws between 2 µA and 10 µA per volt on VIN.

Dimensions

General specifications

Identifying markings

Notes:

1

Without included optional headers or terminal blocks. Height with terminal blocks installed is approximately 0.5".

2

Without included optional headers or terminal blocks.

3

Under typical conditions, where the input voltage is close to the output voltage. Actual achievable continuous output current is a function of input voltage and is limited by thermal dissipation. See the output current graph under the description tab for more information.

4

To -20 V. Connecting supplies over 20 V in reverse can damage the device.

5

While enabled with no load. See the quiescent current graph under the description tab for more information. Can be reduced to under 1 mA using the enable pin.

File downloads

• Drill guide for the S13V25Fx Step-Up/Step-Down Voltage Regulators (17k dxf)

  This DXF drawing shows the locations of all of the board’s holes.

• Dimension diagram of the S13V25Fx Step-Up/Step-Down Voltage Regulators (703k pdf)

• 3D model of the S13V25Fx Step-Up/Step-Down Voltage Regulators (5MB step)