# Adafruit TPS61169 Constant Current Boost Converter for LEDs ## Overview Warning: This breakout is designed for 12V, 24V or multiple LEDs connected in series. It is not meant for powering single 3V LEDs. ![adafruit in led filaments](https://cdn-learn.adafruit.com/assets/assets/000/137/967/medium800/adafruit_products_6354-06.jpg?1750882878 ) The **Adafruit Constant Current Boost Converter for LEDs** makes driving LEDs easy, whether they're in series or parallel - with a chip that can generate up to 40V and 400mA from 3~5V input. Unlike most of our booster chips that generate a fixed voltage (like 5V, or 12V) the **TPS61169** increases the voltage until a set current is being drawn. That makes it excellent for LEDs that are specified in current not voltage. This is perfect for use with our [LED nOOds](https://www.adafruit.com/search?q=noods) and filaments, where sometimes you need up to 12V or 24V at 200mA or so. It's also excellent when you have a bunch of 3V LEDs in series, so they add up to a high voltage, but only at 25mA or 50mA. ![front view of the breakout](https://cdn-learn.adafruit.com/assets/assets/000/137/968/medium800/adafruit_products_6354-04.jpg?1750882937 ) We've used the **TPS61169** in our boards with LED backlights: it's pretty common to see 5 to 7 white LEDs in series and a 30mA current requirement. We like this chip because it has a 1.2A internal switch and automatic over-voltage protection in case the output is disconnected. You can also dim the LEDs via the PWM input pin. It's quiet, efficient, and fairly cool, with 90% efficiency. Since it's constant current it's _not_ good when you need a fixed and stable voltage output like 5V - [for those cases, use Adafruit's everyday boosters](https://www.adafruit.com/search?q=boost). ![gif of a nood being powered by the breakout](https://cdn-learn.adafruit.com/assets/assets/000/137/969/medium800thumb/adafruit_products_6354-06_1.jpg?1750883043 ) Note that you can get up to 40V and up to 400mA but not at the same time. To figure out the approximate power output you can achieve, use the formula: Iout = (Vin \* 1.2A \* 0.9 efficiency) / Vout. So for example, with 5V input, and approx. 12V output you can get 450mA out (the board is limited to 400mA on the switches). For a 24V nOOd, you can get about 225mA out. The current is selectable via mini DIP switches - the default is 25mA and each switch adds 25mA/50mA/100mA/200mA for a total of 400mA. ![back view of the board](https://cdn-learn.adafruit.com/assets/assets/000/137/970/medium800/adafruit_products_6354-02.jpg?1750883093 ) You get one fully assembled breakout with a TPS61169 and required passive components, and a small bit of header. Give 3 to 5V DC on the **IN** and **G** round pins or terminal block. Connect your LEDs on the output port, and you're instantly in business! Note if the output is shorted or opened, you may need to power cycle the chip to get it out of safe-shutdown mode. # Adafruit TPS61169 Constant Current Boost Converter for LEDs ## Pinouts Warning: This breakout is designed for 12V, 24V or multiple LEDs connected in series. It is not meant for powering single 3V LEDs. ![front and back view of the breakout](https://cdn-learn.adafruit.com/assets/assets/000/137/996/medium800/adafruit_products_double.jpg?1750967316 ) ## Power - **Vin / + (terminal block)** - To power the board, give it 3V to 5V DC. The power input pin is broken out at the bottom edge of the board ( **Vin** ) and on the terminal block on the left side of the board ( **+** ). - **G**  / **- (terminal block)** - common ground. The ground pin is broken out at the bottom edge of the board ( **G** ) and on the terminal block on the left side of the board ( **-** ). ## LED Constant Current Output The **TPS61169** increases the voltage being output until a set current is being drawn. That makes it excellent for LEDs that are specified in current, not voltage. Since it's a constant current output, it's not good when you need a fixed and stable voltage output like 5V. - **L+** / **CC Out + (terminal block)** - This is the output that connects to the anode/positive input on your LED. This pin is broken out at the bottom edge of the board ( **L+** ) and on the terminal block on the right side of the board ( **CC Out +** ). By default, it outputs 25 mA before adding additional current through the DIP switch. - **LED-** / **CC Out - (terminal block)** - This is the output that connects to the cathode/negative input on your LED. This pin is broken out at the bottom edge of the board ( **LED-** ) and on the terminal block on the right side of the board ( **-** ). To figure out the approximate current output you can achieve, use the formula: - **Iout = (Vin \* 1.2A \* 0.9 efficiency) / Vout** Info: Use this formula: * Iout = (Vin * 1.2A * 0.9 efficiency) / Vout to figure out the approximate current output you can achieve. ## Current DIP Switch In the center of the board is a four switch DIP switch. These switches let you select the constant current output. When all of the switches are " **OFF**", there is a **default 25 mA** available. The switch is selected/on when they are set to the left towards the  **ON label** on the switch body. Each switch "adds" a different current value to the output, for up to **400 mA on top of the default 25 mA**. They are labeled on the board silk: - The top switch adds **25 mA** - The second from the top adds **50 mA** - The third from the top adds **100 mA** - The bottom switch adds **200 mA** For example, if you needed **250 mA** out, you would turn the top and bottom switches **on** (default 25 mA + 25 mA + 200 mA). Info: By default, the breakout outputs 25 mA when the DIP switches are off. Any additional current with the DIP switches are added on top of the default 25 mA. ## PWM Pin - **PWM** - This is the pulse width modulation input pin. You can dim the LEDs by sending a PWM signal, where the duty cycle determines the total output current. The datasheet provides this formula for calculating your PWM signal: **VFB = Duty \* 204 mV** where **Duty** is the duty cycle of the PWM signal and **204mV** is the internal reference voltage. - The datasheet recommends a PWM frequency between 5kHz to 100kHz. If the PWM frequency is lower than 5kHz, it is out of the low pass filter's range. # Adafruit TPS61169 Constant Current Boost Converter for LEDs ## Use Warning: This breakout is designed for 12V, 24V or multiple LEDs connected in series. It is not meant for powering single 3V LEDs. ![an led nood connected to the breakout](https://cdn-learn.adafruit.com/assets/assets/000/138/030/medium800thumb/adafruit_products_6354-06_1.jpg?1751292473 ) Info: If the output on the breakout is shorted or opened, you may need to power cycle the breakout to get it out of safe-shutdown mode. The Adafruit Constant Current Boost Converter for LEDs makes driving LEDs easy, whether they're in series or parallel. This page will show you how to wire everything up. You'll need an LED, like this [12V nOOd](https://www.adafruit.com/product/5731), and a 3V to 5V power supply. If you are only powering one LED, the LED should require 12V or higher. The breakout is not designed for powering single 3V LEDs. ### nOOds - Flexible LED Filament - 12V 600mm long - Warm White [nOOds - Flexible LED Filament - 12V 600mm long - Warm White](https://www.adafruit.com/product/5731) Our favorite food when hacking on code or electronics is a hot bowl of noodles - and around NYC these are often called 'noods'! What we've got here are flexible LED noodles in different lengths and colors. All are not good for eatin' but they _are _good... In Stock [Buy Now](https://www.adafruit.com/product/5731) [Related Guides to the Product](https://learn.adafruit.com/products/5731/guides) ![Video of two hands playing with a 600mm long LED filament glowing warm white light.](https://cdn-shop.adafruit.com/product-videos/640x480/5731-00.jpg) ### 5V 4A (4000mA) switching power supply - UL Listed [5V 4A (4000mA) switching power supply - UL Listed](https://www.adafruit.com/product/1466) Need a lot of 5V power? This switching supply gives a clean regulated 5V output at up to **4 Amps** (4000mA). 110 or 240 input, so it works in any country. The plugs are "US 2-prong" style so you may need a plug adapter, but you can pick one up at any hardware store for $1 or so,... In Stock [Buy Now](https://www.adafruit.com/product/1466) [Related Guides to the Product](https://learn.adafruit.com/products/1466/guides) ![Angled shot of 5V 4A switching power supply brick with power cable.](https://cdn-shop.adafruit.com/640x480/1466-10.jpg) ### Female DC Power adapter - 2.1mm jack to screw terminal block [Female DC Power adapter - 2.1mm jack to screw terminal block](https://www.adafruit.com/product/368) If you need to connect a DC power wall wart to a board that doesn't have a DC jack - this adapter will come in very handy! There is a 2.1mm DC jack on one end, and a screw terminal block on the other. The terminals are labeled with positive/negative assuming a positive-tip configuration... In Stock [Buy Now](https://www.adafruit.com/product/368) [Related Guides to the Product](https://learn.adafruit.com/products/368/guides) ![Angle shot Female DC Power adapter - 2.1mm jack to screw terminal block](https://cdn-shop.adafruit.com/640x480/368-03.jpg) ## Wiring - **5V Power Supply positive** to **breakout +3-5Vin (red wire)** - **5V Power Supply negative** to **breakout - (black wire)** - **Breakout CC Out +** to **12V LED anode/positive (red wire)** - **Breakout CC Out -** to **12V LED cathode/negative (black wire)** Please note that although a standard 5mm LED is shown in the Fritzing diagram, **it is only to visualize the anode and cathode** on a **12V LED** nOOd. ![fritzing diagram with 5V input and led output](https://cdn-learn.adafruit.com/assets/assets/000/138/031/medium640/adafruit_products_oneLED_tps61169_bb.jpg?1751293861) ## Select Your Maximum Power Supply The DIP switch on the breakout lets you select the current for your LED. The [nOOd LED product page](https://www.adafruit.com/product/5731) has a helpful listing of voltages and current draw. If you aren't sure on the maximum power supply for your LED, you can use this formula: Iout = (Vin \* 1.2A \* 0.9 efficiency) / Vout For this 12V nOOd with a 5V supply, the formula would be: 0.45 = (5 \* 1.2A \* 0.9 efficiency) / 12 Resulting in 0.45 amps aka 450 mA. The breakout has a limit of 425 mA on board (default 25 mA plus the current selection DIP switch), so 425 mA would be the maximum current you could use with this configuration, with all of the switches on the DIP switch set to " **ON**". For another example, lets say you had a 3.3V supply and a 24V LED, like [this nOOd](https://www.adafruit.com/product/5732). The formula becomes: 0.1485 = (3.3 \* 1.2A \* 0.9 efficiency) / 24 Resulting in 0.1485 amps aka 148.5 mA. ## LEDs in Series A common request, especially with fancy LED filaments like [these letters](https://www.adafruit.com/product/6191), is to wire multiple [LEDs together in series](https://en.wikipedia.org/wiki/LED_circuit). This breakout is a great solution for this. You'll still use 3-5V as the input supply and connect your LEDs in series to the output terminal block. You'll set the current on the DIP switches for the **maximum current for one LED**. ### Alphabet LED Filament - Warm White Letter "A" [Alphabet LED Filament - Warm White Letter "A"](https://www.adafruit.com/product/6191) This warm-white glowy letter "A" is made out of COB (chip on board) LEDs, often seen in 'Edison-like' LED bulbs, arranged in different patterns to give a bright, warm lighting effect. They're made of dozens of micro LED diodes that are bonded together on a stiff... In Stock [Buy Now](https://www.adafruit.com/product/6191) [Related Guides to the Product](https://learn.adafruit.com/products/6191/guides) ![Overhead shot of LED in the shape of the letter "A" lit up with alligator clips.](https://cdn-shop.adafruit.com/640x480/6191-00.jpg) - **5V Power Supply positive**  to **breakout +3-5Vin (red wire)** - **5V Power Supply negative**  to **breakout - (black wire)** - **Breakout CC Out + ** to **LED 1 anode/positive in series (red wire)** - **Breakout CC Out -**  to** LED 4 cathode/negative in series (black wire)** LED Wiring - **LED 1 cathode/negative**  to **LED 2 anode/positive** - **LED 2 cathode/negative**  to **LED 3 anode/positive** - **LED 3 cathode/negative**  to **LED 4 anode/positive** ![5V input and four LEDs in series output](https://cdn-learn.adafruit.com/assets/assets/000/138/036/medium640/adafruit_products_seriesLEDs_tps61169_bb.jpg?1751295687) When LEDs are wired in series, you **add their voltages together**. For the wiring diagram above, there are four LEDs and each needs 3V. This means you would need a total of 12V to power them (3V \* 4 LEDs). However, you  **don't use the formula** from earlier to figure out the maximum current draw. You'll set the maximum current that is defined for **one individual LED**. In the case of the LED letter filaments, that's 100 mA maximum. ![adafruit letter filaments powered by the breakout](https://cdn-learn.adafruit.com/assets/assets/000/138/039/medium800/adafruit_products_6354-06.jpg?1751296103 ) # Adafruit TPS61169 Constant Current Boost Converter for LEDs ## Downloads ## Files - [TPS61169 Datasheet](https://cdn-learn.adafruit.com/assets/assets/000/137/971/original/tps61169.pdf?1750883202) - [EagleCAD PCB files on GitHub](https://github.com/adafruit/Adafruit-TPS61169-Constant-Current-Boost-Converter-PCB) - [3D models on GitHub](https://github.com/adafruit/Adafruit_CAD_Parts/tree/main/6354%20TPS61169%20Constant%20Current) - [Fritzing object in the Adafruit Fritzing Library](https://github.com/adafruit/Fritzing-Library/blob/master/parts/Adafruit%20TPS61169%20Constant%20Current%20Boost%20Converter%20LED%20Driver.fzpz) ## Schematic and Fab Print ![schematic for the breakout](https://cdn-learn.adafruit.com/assets/assets/000/137/972/medium800/adafruit_products_schem.png?1750883472 ) ![fab print](https://cdn-learn.adafruit.com/assets/assets/000/137/973/medium800/adafruit_products_fab.png?1750883486 dimensions are in inches) ![](https://cdn-learn.adafruit.com/assets/assets/000/138/028/medium800/adafruit_products_6354_TPS61169_Constant_Current.jpg?1751048394 ) ## Primary Products ### Adafruit TPS61169 Constant Current Boost Converter for LEDs [Adafruit TPS61169 Constant Current Boost Converter for LEDs](https://www.adafruit.com/product/6354) The  **Adafruit Constant Current Boost Converter for LEDs** makes driving LEDs easy, whether they're in series or parallel - with a chip that can generate up to 40V and 400mA from 3~5V input. Unlike most of our booster chips that generate a fixed voltage (like 5V, or 12V)... In Stock [Buy Now](https://www.adafruit.com/product/6354) [Related Guides to the Product](https://learn.adafruit.com/products/6354/guides) ## Featured Products ### nOOds - Flexible LED Filament - 12V 600mm long - Warm White [nOOds - Flexible LED Filament - 12V 600mm long - Warm White](https://www.adafruit.com/product/5731) Our favorite food when hacking on code or electronics is a hot bowl of noodles - and around NYC these are often called 'noods'! What we've got here are flexible LED noodles in different lengths and colors. All are not good for eatin' but they _are _good... In Stock [Buy Now](https://www.adafruit.com/product/5731) [Related Guides to the Product](https://learn.adafruit.com/products/5731/guides) ### nOOds - Flexible LED Filament - Warm White 1.2 meter long - 24V [nOOds - Flexible LED Filament - Warm White 1.2 meter long - 24V](https://www.adafruit.com/product/5732) Our favorite food when hacking on code or electronics is a hot bowl of noodles - and around NYC, these are often called 'noods'! What we've got here are flexible LED noodles in different lengths and colors. All are not good for eatin', but they _are _good... Out of Stock [Buy Now](https://www.adafruit.com/product/5732) [Related Guides to the Product](https://learn.adafruit.com/products/5732/guides) ### Alphabet LED Filament - Warm White Letter "A" [Alphabet LED Filament - Warm White Letter "A"](https://www.adafruit.com/product/6191) This warm-white glowy letter "A" is made out of COB (chip on board) LEDs, often seen in 'Edison-like' LED bulbs, arranged in different patterns to give a bright, warm lighting effect. They're made of dozens of micro LED diodes that are bonded together on a stiff... In Stock [Buy Now](https://www.adafruit.com/product/6191) [Related Guides to the Product](https://learn.adafruit.com/products/6191/guides) ### 5V 4A (4000mA) switching power supply - UL Listed [5V 4A (4000mA) switching power supply - UL Listed](https://www.adafruit.com/product/1466) Need a lot of 5V power? This switching supply gives a clean regulated 5V output at up to **4 Amps** (4000mA). 110 or 240 input, so it works in any country. The plugs are "US 2-prong" style so you may need a plug adapter, but you can pick one up at any hardware store for $1 or so,... In Stock [Buy Now](https://www.adafruit.com/product/1466) [Related Guides to the Product](https://learn.adafruit.com/products/1466/guides) ### Female DC Power adapter - 2.1mm jack to screw terminal block [Female DC Power adapter - 2.1mm jack to screw terminal block](https://www.adafruit.com/product/368) If you need to connect a DC power wall wart to a board that doesn't have a DC jack - this adapter will come in very handy! There is a 2.1mm DC jack on one end, and a screw terminal block on the other. The terminals are labeled with positive/negative assuming a positive-tip configuration... In Stock [Buy Now](https://www.adafruit.com/product/368) [Related Guides to the Product](https://learn.adafruit.com/products/368/guides) ## Related Guides - [Rumi Sword - KPop Demon Hunters](https://learn.adafruit.com/rumi-sword.md) - [Adafruit nOOds Überguide](https://learn.adafruit.com/noods-uberguide.md) - [Mini Neon Sign Prop & n00ds Booster Case](https://learn.adafruit.com/nood-booster-case.md) - [Adafruit ESP32-S3 Feather](https://learn.adafruit.com/adafruit-esp32-s3-feather.md) - [Adafruit Audio FX Sound Board](https://learn.adafruit.com/adafruit-audio-fx-sound-board.md) - [Mario Magic Wand](https://learn.adafruit.com/mario-magic-wand.md) - [Arduino Lesson 8. 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