Output voltage range Typical max current output 1 Input voltage range 2 Low-voltage cutoff 1.4 V – 7 V 3.4 A 3.3 V – 45 V adjustable 1 Typical continuous output current at 30 V in and 3.3 V out.
Special Order
Shipping from $2.90
+84 more from our supplier in 7-10 days
Our Code: SKU-010589
Supplier Link: [Pololu MPN:4872]
The D30V3x line of synchronous buck (step-down) voltage regulators generates lower output voltages from input voltages as high as 45 V. They are switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters), which makes them much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. These regulators can typically support continuous output currents between 1 A and 4.5 A, depending on the input voltage and output voltage. In general, the available output current decreases as the input and output voltages increase.
This line consists of the D30V30Fx family of fixed output voltages ranging from 3.3 V to 15 V and two families of adjustable versions that allow the output voltage to be set with a precision 11-turn potentiometer. Each adjustable option is available with or without an adjustable low-voltage cutoff (also set through a precision 11-turn potentiometer on the versions that have it). The adjustable families are the D30V30MAx, which is the more compact of the two thanks to its double-sided assembly, and the D30V33MAx, which includes larger through-holes for terminal blocks and can do slightly more current thanks to its larger surface area. The following table shows all of the members of the D30V3x line:
Regulator | Output voltage | Typical max output current1 |
Input voltage2 | Adjustable low-voltage cutoff |
Size | Price |
---|---|---|---|---|---|---|
#4891: D30V30F3 | 3.3 V | 3.7 A | 3.3 V – 45 V | – | 0.7″ × 0.8″ | $12.95 |
#4892: D30V30F5 | 5 V | 3.4 A | 5 V – 45 V | $12.95 | ||
#4893: D30V30F6 | 6 V | 3.3 A | 6 V – 45 V | $13.95 | ||
#4894: D30V30F7 | 7.5 V | 3 A | 7.5 V – 45 V | $13.95 | ||
#4895: D30V30F9 | 9 V | 2.9 A | 9 V – 45 V | $13.95 | ||
#4896: D30V30F12 | 12 V | 2.8 A | 12 V – 45 V | $13.95 | ||
#4897: D30V30F15 | 15 V | 2.7 A | 15 V – 45 V | $13.95 | ||
#4873: D30V30MAL | 1.4 V – 7 V | 3.4 A | 3.3 V – 45 V | – | 0.6″ × 1.0″ | $16.95 |
#4872: D30V30MALCMA | $19.95 | |||||
#4875: D30V30MAS | 4.2 V – 15 V | 3 A | 4.2 V – 45 V | – | $16.95 | |
#4874: D30V30MASCMA | $19.95 | |||||
#4853: D30V33MAL | 1.4 V – 7 V | 3.8 A | 3.3 V – 45 V | – | 0.9″ × 1.2″ | $17.95 |
#4852: D30V33MALCMA | $20.95 | |||||
#4855: D30V33MAS | 4.2 V – 15 V | 3.3 A | 4.2 V – 45 V | – | $17.95 | |
#4854: D30V33MASCMA | $20.95 | |||||
1At 30 V in. Actual achievable continuous output current is a function of input and output voltages and is limited by thermal dissipation. | ||||||
2Operating voltage must be higher than the set output voltage and is subject to dropout voltage considerations. |
The regulators have reverse voltage protection up to 40 V, input under-voltage lockout, over-current protection, and short-circuit protection. 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.
If you need higher input voltages, consider the similar D36V28Fx family, which works up to 50 V in, and if you need more output current, consider the similar D36V50Fx family of step-down voltage regulators.
We manufacture these boards in-house at our Las Vegas facility, which gives us the flexibility to make these regulators with customised components to better meet the needs of your project. For example, if you have an application where the input voltage will always be below 20 V and efficiency is very important, we can make these regulators a bit more efficient at high loads by replacing the 40V reverse voltage protection MOSFET with a 20V one. We can also customise the output voltage. If you are interested in customisation, please contact us for a quote.
This item is the D30V30MALCMA, which has an adjustable output voltage (1.4 V to 7 V) and an adjustable low-voltage cutoff (see the D30V30MAL for a version of this regulator with no low-voltage cutoff, and see the D30V30MASCMA for a version of this regulator with a higher output voltage range):
Fine-Adjust Step-Down Voltage Regulator w/ Adjustable Low-Voltage Cutoff D30V30MAxCMA, side view showing output voltage and cutoff adjustment potentiomenters (D30V30MASCMA version shown).
Fine-Adjust Step-Down Voltage Regulator D30V30MAx, bottom view with dimensions (D30V30MAS version pictured).
Fine-Adjust Step-Down Voltage Regulator w/ Adjustable Low-Voltage Cutoff D30V30MAxCMA labeled pinout (D30V30MASCMA version shown).
This regulator has six connections: power good (PG), enable (EN), input voltage (VIN), output voltage (VOUT), and two ground (GND) connections.
The “power good” indicator, PG, is an open-drain output that goes low when the regulator’s output voltage either rises more than 7.5% (typical) above or falls more than 9% (typical) below the voltage it is trying to maintain (with hysteresis). An external pull-up resistor is required to use this pin.
The EN pin is part of the low-voltage cutoff circuit. When the voltage on this pin falls below a specific threshold, the regulator enters a low-power shutdown state. This can happen when the input voltage falls below the set low-voltage cutoff threshold, or it can be externally triggered by driving the EN pin low. The shutdown current draw in this sleep mode is dominated by the low-voltage cutoff circuit (see the low-voltage cutoff section below for more information) and in the reverse-voltage protection circuit (which contributes less than 10 µA per volt on VIN). In general, the quiescent and shutdown currents are reduced by increasing the cutoff voltage threshold. (Note that for high input voltages, the shutdown current draw when it is disabled can be greater than the quiescent draw while enabled; see the quiescent current graph below for more details.)
The input voltage, VIN, powers the regulator. Voltages between 3.3 V and 45 V can be applied to VIN. When the output voltage is greater than 3.3 V, the effective lower limit of VIN is VOUT plus the regulator’s dropout voltage, which varies approximately linearly with the load (see below for graphs of the dropout voltage as a function of the load).
VOUT is the regulated output voltage, which can be set between 1.4 V and 7 V with the output voltage adjustment potentiometer.
![]() ![]() |
The output voltage is controlled with an 11-turn precision potentiometer that allows for an output range of 1.4 V and 7 V. Turning the potentiometer clockwise increases the output voltage. The regulator ships with a the voltage set to around 1.5 V by default.
![]() ![]() |
The low-voltage cutoff threshold is also controlled with an 11-turn precision potentiometer, and turning the potentiometer clockwise increases the cutoff voltage. The regulator ships with the cutoff voltage set below 3.3 V, low enough that it should start by default for any input voltage in its operating range. In general, the quiescent and shutdown currents are reduced by increasing the cutoff voltage threshold.
Cutoff voltage settings for the 1.4-7V Fine-Adjust Step-Down Voltage Regulator w/ Adjustable Low-Voltage Cutoff D30V3xMALCMA.
Schematic diagram of the enable (EN) circuit on the 1.4-7V Fine-Adjust Step-Down Voltage Regulator w/ Adjustable Low-Voltage Cutoff D30V3xMALCMA.
The EN pin has a precise cutoff threshold (typically 0.85 V, but unit-to-unit variation can put it anywhere between 0.65 V and 1.05 V), and the cutoff adjustment potentiometer is part of a voltage divider circuit, as shown on the right, that determines the relationship between VIN and the voltage on EN. We have two recommended techniques for setting the cutoff voltage:
Technique A: Power the regulator at the desired cutoff voltage and, with the regulator enabled, turn the cutoff potentiometer clockwise until the regulator turns off. This is the simplest approach, and we recommend it in situations where a supply at the desired cutoff voltage is available.
Technique B:
``"EN" = "EN cutoff" * "VIN" / "VIN cutoff"``
``"EN" = "0.85 V" * "9 V" / "6 V" = "1.275 V"``
Note: There is approximately 200 mV of hysteresis on the EN threshold, which means that the activation threshold for EN rising is about 200 mV higher than the shutdown threshold for EN falling. This means that the regulator will typically require an input voltage around 125% of the cutoff voltage to begin operating.
The six connection through-holes are arranged on a 0.1″ grid for compatibility with solderless breadboards, connectors, and other prototyping arrangements that use a 0.1″ grid. A 6×1 straight male header strip and a 6×1 right-angle male header strip are included with the regulator.
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.
The maximum achievable output current of these regulators 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 these regulators 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.
The quiescent current is the current the regulator uses just to power itself, and the graph below shows this for the different regulator versions as a function of the input voltage. The data in the graph shows the quiescent current with the low-voltage cutoff set to its minimum value of 2.7 V; in general, the quiescent (and shutdown) currents are reduced by increasing the cutoff voltage threshold.
![]() |
The dropout voltage of a step-down regulator is the minimum amount by which the input voltage must exceed the regulator’s target output voltage in order to ensure the target output can be achieved. For example, if a 5 V regulator has a 1 V dropout voltage, the input must be at least 6 V to ensure the output is the full 5 V. Generally speaking, the dropout voltage increases as the output current increases. The graph below shows the dropout voltages at several different output voltages as a function of output current:
![]() |
Size: | 0.6″ × 1.0″ × 0.35″1 |
---|---|
Weight: | 3.6 g1 |
Minimum operating voltage: | 3.3 V2 |
---|---|
Maximum operating voltage: | 45 V |
Minimum output voltage: | 1.4 V3 |
Maximum output voltage: | 7 V3 |
Continuous output current: | 3.4 A4 |
Reverse voltage protection?: | Y5 |
Maximum quiescent current: | 20 mA6 |
Low-voltage cutoff: | adjustable |
Output type: | adjustable 1.4V-7V |
PCB dev codes: | reg32b |
---|---|
Other PCB markings: | 0J14388 |
This DXF drawing shows the locations of all of the board’s holes.