Product Description: PololD24V3ALV - 2.5V step-down converter - 7.5V 0.3A.
The adjustable DC-DC converter has a wide input voltage range from 4.5 V to 42 V. It has an efficiency of 80%. The output voltage is set using a potentiometer. The available range is 2.5 V to 7.5 V. The output voltage must not exceed the input voltage.
The module has four outputs:
- VIN - input voltage,
- GND - mass potential,
- VOUT - output voltage,
- SHDN - system shutdown.
If the SHDN pin shows a low state (below 0.3 V), the inverter is switched off and the current consumption does not exceed 20 uA. If the high state (above 2.3 V) appears on the SHDN pin, the system will be activated again. The output can be permanently connected to the VIN or left unconnected if the shutdown mode is not used.
Output voltage is determined by means of a potentiometer. Setting the voltage higher than input will not damage the system. However, large oscillations will occur. So it is recommended not to set the voltage higher than the input one.
Output voltage oscillogram. VIN is 5V. VOUT is set above 5V.
Output voltage selection
Turning the potentiometer clockwise will increase the output voltage.
The graph showing the relation between the output five and the potentiometer position for 4-25V and 2.5-7.5V converters.
Efficiency and output current
Efficiency is defined as the ratio of output power to input power (Power out)/(Power in). This is a very important parameter when working with portable energy sources (batteries and accumulators), where the time of operation on one charging cycle counts. The efficiency dependence on the input voltage is shown in the graphs below.
Dangerous voltage pulses
When connecting the power supply to the module, dangerous, short, high amplitude eclectic impulses (so-called pins) may appear, which may permanently damage the system. Polol's tests show that for voltages above 20V, the pins may have an amplitude exceeding 42V. In order to protect against this undesirable phenomenon it is recommended to solder a capacitor of at least 33 uF as close as possible to the pins powering the converter.
More details on the manufacturer's website .
Technical specifications of the step-down 2.5 V - 7.5 V 0.3 A
- Input voltage: 4.5 V to 42 V
- Output voltage adjustable: 2.5 V to 7.5 V
- Maximum output current: 300 mA
- 500 kHz switching frequency
- Built-in protection (breaker) to protect against excessive current consumption and excessive temperature
- Dimensions: 15.3x 10.2 x 4mm
- Weight: 1g (without connectors)