We are offering these carrier boards with support from Allegro Microsystems as an easy way to use or evaluate their APM81815 step-down voltage regulators; we therefore recommend referencing the APM81815 datasheet (2MB pdf) for detailed documentation of the regulator IC operation.
The APM81815 is a synchronous buck (step-down) voltage regulator that generates lower voltages from input voltages as high as 72 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 0.5 A and 1.5 A, depending on the input voltage and output voltage (see the Maximum continuous output current section below). In general, the available output current decreases as the input voltage increases.
This family includes four versions, one for each output voltage supported by the APM81815:
| Item # |
Output voltage |
Typical max
output current(1) |
Input voltage range(2) |
Size |
| #5266 |
3.3 V |
1.1 A |
5 V – 72 V |
0.4″ × 0.75″ |
| #5267 |
5 V |
1.1 A |
5.05 V – 72 V |
| #5268 |
5.35 V |
1.1 A |
5.4 V – 72 V |
| #5269 |
12 V |
0.8 A |
12.1 V – 72 V |
|
| Note 1: At 48 V in. Actual achievable continuous output current is a function of input voltage and is limited by thermal dissipation. See the output current graphs on the product pages for more information. |
|
| Note 2: Minimum input voltage is subject to dropout voltage considerations; see the dropout voltage section of product pages for more information. |
Features
- Input voltage: 5 V to 72 V (subject to dropout considerations)
- 2% output voltage accuracy
- Typical maximum continuous output current: 0.5 A to 1.5 A
- Typical efficiency of 50% to 95%, depending on input voltage, output voltage and load (see the efficiency graphs on the product pages)
- Switching frequency: ~1 MHz under heavy loads
- < 0.1 mA typical no-load quiescent current (see the quiescent current graph on the product pages)
- Optional enable input with precision threshold can be used for simple on/off control or to implement a custom low-voltage cutoff
- Soft-start feature limits inrush current and gradually ramps output voltage
- Short-circuit and over-temperature protection
- PCB is 4-layer, 2-oz copper for improved thermal dissipation
- Small size: 0.4″ × 0.75″ × 0.13″ (10.2 mm × 19.1 mm × 3.2 mm)
- Weight: 1.0 g
Compare all products in this category
Products in category “APM81815 Step-Down Voltage Regulator Carriers”
| Output voltage |
Typical max output current1 |
Input voltage range2 |
Size |
| 3.3 V |
1.1 A |
5 V – 72 V |
0.4″ × 0.75″ |
Note 1: At 48 V in. Actual achievable continuous output current is a function of input voltage and is limited by thermal dissipation. See the output current graphs on the product pages for more information.
Note 2: Minimum input voltage is subject to dropout voltage considerations; see the dropout voltage section of product pages for more information.
| Output voltage |
Typical max output current1 |
Input voltage range2 |
Size |
| 5 V |
1.1 A |
5.05 V – 72 V |
0.4″ × 0.75″ |
Note 1: At 48 V in. Actual achievable continuous output current is a function of input voltage and is limited by thermal dissipation. See the output current graphs on the product pages for more information.
Note 2: Minimum input voltage is subject to dropout voltage considerations; see the dropout voltage section of product pages for more information.
| Output voltage |
Typical max output current1 |
Input voltage range2 |
Size |
| 5.35 V |
1.1 A |
5.4 V – 72 V |
0.4″ × 0.75″ |
Note 1: At 48 V in. Actual achievable continuous output current is a function of input voltage and is limited by thermal dissipation. See the output current graphs on the product pages for more information.
Note 2: Minimum input voltage is subject to dropout voltage considerations; see the dropout voltage section of product pages for more information.
| Output voltage |
Typical max output current1 |
Input voltage range2 |
Size |
| 12 V |
0.8 A |
12.1 V – 72 V |
0.4″ × 0.75″ |
Note 1: At 48 V in. Actual achievable continuous output current is a function of input voltage and is limited by thermal dissipation. See the output current graphs on the product pages for more information.
Note 2: Minimum input voltage is subject to dropout voltage considerations; see the dropout voltage section of product pages for more information.
