TPL5110 Nano Power Timer Hookup Guide

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2026-02-20 | By SparkFun Electronics

Courtesy of SparkFun Electronics

Guide by Elias The Sparkiest

Introduction

The TPL5110 Nano Power Timer is ideal for applications that require low power, and especially those projects that are running off of a LiPo battery. The Nano Power Timer will turn on your project, most likely a microcontroller, after the set amount of time, continuously. When your microcontroller has completed whatever needs doing, sampling air quality for example, it can then signal back to the Nano Power Timer to turn it off. While the project is off, the Nano Power Timer will only consume 35nA of power until the timer turns the project back on again. In this tutorial, we'll discuss how the time is set with the on board six DIP switch and use a microcontroller to turn it off when a task is finished.

SparkFun Nano Power Timer - TPL5110

Required Materials

To follow along with this tutorial, you will need the following materials. You may not need everything though depending on what you have. For example, I chose the RedBoard as a simple demo, but you could use any microcontroller. Add it to your cart, read through the guide, and adjust the cart as necessary.

Jumper Wires - Connected 6" (M/M, 20 pack)
Lithium Ion Battery - 400mAh
Straight Header - Male (PTH, 0.1in., 40-Pin)
SparkFun RedBoard Turbo - SAMD21 Development Board
Breadboard - Mini Modular (White)
SparkFun Traveler microB Cable - 1m

Tools

You will need a soldering iron, solder, general soldering accessories, and a diagonal cutter.

Hardware Overview

Power and LiPo Battery

The Nano Power Timer can handle voltages between 1.8V - 5.5V and current up to 1.1 Amps. There are two options when connecting power to the Nano Power Timer. The first and more obvious option is the on board LiPo Battery Connector. The second is the VDD and GND pins on the five pin header underneath the IN label (short for INPUT). The power you provide to the INPUT side will flow out the OUTPUT side to power your microcontroller or project. If your using a LiPo battery, then do not attach another power source to these pins.

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Image of TPL5110 Nano Power Timer Hookup Guide Bottom

The OUT (OUTPUT) power is labeled VDD_OUT and GND. These pins will go to the board or project that you are powering.

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Timer and Delay Switch

Note: As reported in the datasheet, the resistance corresponding to the given time has a certain margin of error. The example given in the datasheet is a desired 600 second time which would require a resistance that falls in the window: 56.96kΩ-57.44kΩ. The resistor values on the board have a 1% tolerance as well. The tolerance of the resistors and margin of error makes it imprudent to try and use this product for HIGH precision applications.

The Nano Power Timer's main function is to turn your microcontroller on after a set amount of time, continuously. The board has a six DIP switch that controls this time by changing resistance to the timer pin on the IC. To the left of the switch are five letters labeling each switch. On the underside of the board are these letters and the amount of time that is set when the corresponding switch is flipped.

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Image of TPL5110 Nano Power Timer Hookup Guide Bottom

This time is set when the board is powered up, so cycle power after you select your time. Check the table below to find a time suitable for your project.

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If you're time is not listed then we've left two additional pads for a custom time: one SMD and the other PTH. These two spaces are labeled with F on the product and their corresponding switch is labeled the same. If you decide to use them both at the same time their resistance is in parallel so make sure to calculate accordingly.

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Note: Regardless of how long your application takes to complete what it needs to do, the Nano Power Timer will always turn the board on at the chosen interval. For example, a two second blink of an LED will not delay a 10 second interval by two seconds (making the delay 12 seconds). Instead the LED will turn back on after 8 seconds because the two second delay cuts into the 10 second interval.

More Timer Options

You are not limited to the times that are represented on the silk. Ignoring the Custom switch option, there are 26 possible combinations of switches aside from the five printed on the board that yield times from three seconds up to 15 minutes. The chart below gives you the combination of ON resistors, their combined resistance, and their approximate time. A few redundant resistances were omitted.

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Some of these times are approximate, but I have provided a Python script in the resources below to help you calculate what your exact time is. This will differ by small margins for each board due to the tolerance of the resistors.

Additional Timer Options From Datasheet

Below is the list of available times from the datasheet that are not included in the charts above. Of note are the timer options in the millisecond range. You can access these times by taking advantage of the two empty resistor pads on the Nano Power Timer.

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Push Button

The push button on the product will manually begin the timer. This allows you to test the timer and your project which should send an OFF signal to the Done pin.

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LED

There's a single red power LED on the topside of the product which indicates power is being supplied to the OUT pins. If you want to disconnect this LED, simply cut the trace between the jumper on the underside of the board labeled LED.

Image of TPL5110 Nano Power Timer Hookup Guide Power LED

Image of TPL5110 Nano Power Timer Hookup Guide Power LED Jumper

Header

Next to GND is the DONE pin that tells the product to turn your microcontroller or project off. To do this, your microcontroller or project will need to send a digital signal from LOW to HIGH to this pin. Finally, the DRV pin is active high and will start the timer of your project when the pin receives a HIGH signal. This is the same function as the on board push button. Not very many people will want to attach a different button, but if you wanted to, this would be the place.

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How Do I Check the Exact Time?!

I've provided a simple Arduino sketch below to calculate the exact timing of the timer setting. You'll attach the VOUT pin to a digital I/O pin on your microcontroller and the sketch will start its timer when the power is high and end the timer when the power is off.

Nano Power Timer Checker (INO)

Hardware Hookup

⚡ Warning! When powering a microcontroller to the Arduino via USB, you will need to disconnect the TPL5110 from the Arduino's power input. The conflicting power sources will damage the TPL5100. You may want to consider adding a Schottky Diode between the TPL5110's output voltage and the microcontroller's voltage input.

Schottky Diode

Note: Depending on your microcontroller, you may need to add a pull-down resistor on the Done pin. We found that the SAMD21 and SAMD51 boards required a pull-down resistor to trigger the TPL5110's Done pin reliably.

Resistor 10K Ohm 1/4 Watt PTH - 20 pack (Thick Leads)

We're going to power a RedBoard Turbo with a 3.7V LiPo Battery and set it to a 14 second delay. By default, the board comes with every switch flipped to the ON position which is 3 second timer. To set the timer to 14 seconds, we'll turn some switches to the ON position and others to the OFF position. I used tweezers because the switches were too small for my hands.

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To get a 14 second delay switches 'A' + 'D' + 'E' must be flipped ON, and the other switches flipped OFF. Next solder a 6 pin header of your choice to the Nano Power Timer. After the six pin header is soldered to the Nano Power Timer, plug in three wires into the female header as follows:

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We'll use a Schottky diode to protect the TPL5110 when the RedBoard Turbo is connected to a computer when prototyping and uploading code. Additionally, we'll add a pull-down resistor on the Done pin. Depending on your microcontroller, you may not need resistor. After wiring your circuit together, you may have something similar to the image below without the battery connected.

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Let's move onto the code.

Note: If you are looking to reduce the number of components used with the TPL5110 and a microcontroller, you could solder wire directly to the PTH pins, remove the pull-down resistor, and Schottky diode. Just make sure to disconnect the VOUT pin whenever you are connecting a USB cable to your microcontroller to upload.

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Simple Example

Note: If this is your first time using Arduino, please review our tutorial on installing the Arduino IDE. If you've never connected an SAMD21 device to your computer before, you will need to install the board add-on and may need to install drivers. Check out our section on UF2 Bootloader and Drivers and Setting Up Arduino for help with the installation.

With this example we'll be laying out the very basics of how the Nano Power Timer works. Copy the code and paste in the Arduino IDE. Select your board (in this case, the RedBoard Turbo), COM port, and hit the upload button to upload in the Arduino IDE.

The Nano Power Timer is powered by a LiPo Battery and will turn on a RedBoard Turbo every 14 seconds. The RedBoard Turbo will blink it's blue LED, and then send a done signal back to the Nano Power Timer, which will turn off the RedBoard Turbo.

Regardless of how long your application takes to complete what it needs to do, the Nano Power Timer will always turn the board on at the chosen interval. For this simple example, the one second blink of the LED does NOT impact the 14 second interval.

Copy Code

/*
TPL5110_Blink_Demo_example.ino

  Simple Example Code for the TPL5110 Nano Power Timer Hookup Guide. This code
  simply blinks the pin 13 LED and writes pin 4 (donePin pin) high. This shift from
  LOW to HIGH of the donePin pin, signals to the Nano Power Timer to turn off the
  microcontroller.
  SparkFun Electronics
  Date: May, 2019
  Author: Elias Santistevan
*/

int led = 13; // Pin 13 LED
int donePin = 4; // Done pin - can be any pin.  

void setup(){

  pinMode(led, OUTPUT); 
  pinMode(donePin, OUTPUT); 

}

void loop(){
  // Blink. 
  digitalWrite(led, HIGH); 
  delay(1000); 
  digitalWrite(led, LOW); 
  delay(1000); 

  // We're done!
  // It's important that the donePin is written LOW and THEN HIGH. This shift
  // from low to HIGH is how the Nano Power Timer knows to turn off the
  // microcontroller. 
  digitalWrite(donePin, LOW); 
  digitalWrite(donePin, HIGH); 
  delay(10);
}

After uploading this code, and plugging in the LiPo battery into the Nano Power Timer, the RedBoard Turbo will blink once, be turned off by the Nano Power Timer, and then will turn on again 12 seconds later (14 second timer - 2 second delay in sketch).

Note that the Power LED on the Nano Power Timer turns on when it provides power to your microcontroller.

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This Nano Power Timer really shines when you're doing remote projects that are running off of battery and you need to maximize the life of the battery! There's only so much deep sleeping that you can do in code, and nothing will compare to 35nA of power consumed in the off state of the Nano Power Timer. You just need one additional GPIO or some method of sending a digital signal that can go from LOW to HIGH to signal OFF to the Nano Power Timer.

Note: Don't forget! We've also broken out INPUT power pins, so you're not limited to just a LiPo battery. Check out the list below for other power connectors for additional power options (not a complete list)!

Resources and Going Further

Now that you've successfully got your TPL5110 Nano Power Timer up and running, it's time to incorporate it into your own project! For more information, check out the resources below: