The XL-10AL is a small 12.8x22.7mm breakout board with a highly power-efficient bistable switch that works both with 3.3V and 5V microcontrollers at just 120-350nA quiescent current.
The 10AL in XL-10AL stands for 10A and low, and there is also a XL-10AH. The H stands for high and refers to the voltage range: it can handle voltages from 4.5-26V (i.e. if you wanted to switch 12V car electric)
Overview
The board comes with four solder pads: Vin and GND are connected to the power supply (i.e. a battery), and Vout and GND are connected to the device you want to control. The voltage you feed in is the voltage you get out.
A push button can be used to manually toggle the switch.
When the built-in push button is pressed, it essentially pulls a pin in the circuitry to low. That’s why you can toggle the switch via a GPIO or an external push button just as easily:
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Programmatically: pull down either one of the two marked solder pads for a short period of time with a microcontroller GPIO, simulating a button press.
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External Button: connect an external momentary push button (normally open) to GND and one of the two solder pads marked GPIO low.
Caveat
The vendor has published instructions on how to connect external buttons and added this misleading image for illustration:
It appears as if you could toggle the bistable switch either by pulling up one pin, or by pulling down another pin. That’s however not the case.
The labels VIN and GND in the image refer to the power connectors and do not relate to the push button. Both left push button contacts are interconnected, and both right push button contacts are interconnected as well.
So both external push buttons in this drawing do exactly the same and short-circuit the built-in push button.
Since the left side of the push button is connected to GND, toggling is performed by pulling the right side of the push button to ground - either by pressing the built-in push button, or by short-cutting the built-in push button with an external button, or by pulling either one of the right contacts to low.
EC8D-01B
The EC8D-01B used on this board is an ultra-low-power electronic toggle-switch controller that changes its output state each time a momentary pushbutton is pressed.
It operates at 2–5 V, consumes at most 2 µA at 3 V without load for the controller IC itself (not the entire module), and provides an active-low output (LOW when ON, high-impedance when OFF) suitable for controlling external switching circuitry.
State Control
The board is a simple toggle switch so each new pulse to GND toggles its state. There is no dedicated status output pad, but you can determine the latched state by tapping into the switch controller’s output.
If you use this board with microcontrollers, i.e. to let a microcontroller turn itself off programmatically, knowing the actual switch state can be particularly useful.
To do so, you can read pin 4 (OUT) of the EC8D-01B. In the XL-10AL, this pin connects directly to the P-channel MOSFET gate and to a 5.1 kΩ pull-up resistor (R1) tied to VIN:
| Latched state | EC8D-01B pin 4 (OUT) |
Voltage at the board’s OUT node (VIN present) |
|---|---|---|
| OFF | High impedance | Approximately VIN, via R1 |
| ON | Pulled LOW | Approximately 0 V |
You can solder to pin 4 or the connected R1/MOSFET-gate node, as shown in the schematic. This senses the commanded latch state, rather than independently confirming that VOUT is delivering power.
The module must have VIN and share GND with the microcontroller. With VIN disconnected, OUT does not give a valid latch indication; an ESP32 input with a pull-up would read HIGH even if the module is unpowered.
Caveat: 3.3 V Microcontrollers
In the OFF state, R1 pulls OUT up to VIN. Since the board is rated for 3.5–5.4 V, that could put 5 V on an ESP32 GPIO if you connected it directly.
To isolate the GPIO from this higher voltage, use a diode. It blocks current from the module’s HIGH pull-up while allowing OUT to pull the GPIO LOW when the switch is ON.
Use a standard 1N4148 signal diode, with its anode connected to the ESP32 GPIO (pulled up to the ESP32’s own 3.3 V) and its cathode (striped end) connected to OUT. The pull-up can be an external 10 kΩ resistor as in the drawing, or the ESP32’s internal pull-up; this resistor is separate from the module’s 5.1 kΩ R1.
The GPIO then reads LOW when ON and HIGH when OFF, as long as the XL-10AL is powered. Configure the GPIO as an input with a pull-up, not as an output.
Voltage and Current
The vendor markets this bistable switch as power switch for high currents of up to 10A, and the published specs apply to high current use cases only:
| Item | Value |
|---|---|
| Current | max. 10A |
| Voltage | 3.5-5.4V |
| Voltage Drop | max. 130mV |
| Quiescent Current | 300nA |
For currents >5A, the voltage should be >4V, and an additional heat sink may be required.
Microcontroller Use-Case
With low currents (around 200mA, as is common in microcontroller projects), actual measurements look quite differently. These are observed test conditions, not new maximum ratings:
| Item | Value |
|---|---|
| Test Current | 200mA (not a maximum) |
| Tested Voltage Range | 2.8-5.4V (below 3.5 V is outside the vendor rating) |
| Voltage Drop | No noticeable drop at the tested current |
| Quiescent Current | 120-300nA (depending on operating conditions) |
3.3V Microcontroller
Operating the XL-10AL with 3.3V is officially out of spec but entirely possible: as long as you switch small currents, the MosFET works just fine.
With currents around 200mA (as is common in microcontroller projects), voltages below 3V perform well, and the quiescent current in off state is much smaller than 300nA (around 120nA). Another benefit is the absence of any noticeable voltage drop.
To verify, the graph below shows a measurement series at 2.98V input voltage (simulating a nearly empty LiIon battery), and drawing a current of 200mA:
The graph in the middle shows that 200mA could be delivered ok in on state. In off state, the quiescent current is merely 120nA in the average.
High Currents
This board can switch surprisingly high currents of up to 10A, however when current exceeds a few Ampere, the voltage must be higher than 4.5V.
At lower voltages, the MosFET can only handle small currents. If the current exceeds the transport capabilities of the MosFET, its resistance raises, and the MosFET heats up, causes a voltage drop, and can be destroyed.
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(content created Oct 14, 2024 - last updated Oct 26, 2026)