📋 Overview
The F23J5V3A1S-C is a compact, waterproof (IP68) DC-DC step-down (buck) converter that takes a DC input of 8V to 23V (nominally 12V) and converts it to a stable 5V DC output at up to 3A (15W maximum). The output is delivered through a USB-C connector on a flexible cable, making it convenient for charging phones, tablets, GPS units, dash cams, and other USB-powered devices from a vehicle, boat, solar panel, or battery system.
This module uses a switching regulator design, which means it's highly efficient (85–95%) and generates very little heat compared to a linear regulator. The entire module is sealed in an epoxy-filled waterproof housing, making it suitable for outdoor, marine, and under-hood automotive installations.
⚠️ Important: This module outputs 5V only and does not include a USB Power Delivery (PD) negotiation chip. It will charge most devices that accept standard 5V USB charging, but it will not fast-charge devices that require PD negotiation — and some devices may limit their current draw significantly. See the Understanding USB-C and Power Delivery section below for full details.
⭐ Key Features
- Wide Input Voltage Range — Accepts 8V to 23V DC, suitable for 12V automotive, marine, and solar systems
- Stable 5V 3A Output — Delivers up to 15W of regulated power through a USB-C connector
- IP68 Waterproof — Fully sealed epoxy housing rated for dust-tight and submersion protection
- High Efficiency — 85–90% typical, up to 95% maximum, minimizing heat and wasted energy
- Built-In Protections — Overload, over-current, over-voltage, and low-voltage protection with auto recovery
- Compact and Lightweight — Only 46 × 27 × 14 mm and 36g, easy to mount in tight spaces
- Mounting Tabs — Integrated tabs with screw holes for secure installation
📊 Specifications
| Model | F23J5V3A1S-C |
| Converter Type | DC-DC Step-Down (Buck) |
| Topology | Non-Isolated |
| Input Voltage | 8V – 23V DC (12V nominal) |
| Output Voltage | 5V DC (fixed) |
| Maximum Output Current | 3A |
| Maximum Output Power | 15W |
| Efficiency | 85–90% typical, 95% maximum |
| Voltage Regulation | ±1% |
| Load Regulation | ±2% |
| Output Ripple (Full Load) | < 150mV |
| No-Load Current | < 100mA |
| Output Connector | USB Type-C (male) |
| Input Connection | Bare wire leads (Red = positive, Black = negative) |
| Input Wire Length | Approx. 135 mm (5.3 inches) |
| Output Cable Length | Approx. 300 mm (11.8 inches) |
| Waterproof Rating | IP68 |
| Operating Temperature | -25°C to +60°C |
| Protections | Overload, over-current, over-voltage, low-voltage (auto recovery) |
| Module Dimensions | Approx. 46 × 27 × 14 mm (1.81 × 1.06 × 0.55 inches) L × W × H |
| Overall Length (with tabs) | Approx. 63 mm (2.48 inches) |
| Weight | 36g (1.3 oz) |
| Case Color | Black |
📏 Dimensions
A 3D mechanical drawing and STEP file are available for this module for integration into your enclosure or mounting designs.
- 3D Mechanical Drawing (PDF): Download Mechanical Drawing
- STEP File (3D CAD Model): Download STEP File
🔌 Wiring and Installation
The input side of this module has two bare wire leads. Connecting them correctly is essential for safe operation.
Input Wiring
| Wire Color | Connection |
|---|---|
| Red | Positive (+) terminal of your DC power source |
| Black | Negative (−) / Ground terminal of your DC power source |
Installation Steps
- Verify your input voltage. Confirm that your power source provides between 8V and 23V DC. Common sources include 12V car batteries, 12V marine batteries, solar charge controllers, and DC power supplies.
- Disconnect power from your source before making any connections.
- Strip the input wires if needed — expose approximately 5–8 mm of bare copper on each lead.
- Connect the red wire to the positive (+) terminal of your power source.
- Connect the black wire to the negative (−) / ground terminal of your power source.
- Secure the connections using crimp connectors, solder and heat shrink, or screw terminals appropriate for your installation. Avoid simple wire twists — they can work loose with vibration.
- Mount the module using the built-in mounting tabs and appropriate screws. Choose a location that is accessible but protected from physical damage.
- Apply power and plug your USB-C device into the output connector to verify operation.
⚠️ Important: Double-check polarity before applying power. While the module has built-in protections, reversed polarity can damage the module and is not covered by the protection circuitry. Red wire = positive, Black wire = negative.
Recommended Fusing
It's good practice to install an inline fuse on the positive (red) input wire, close to the power source. A 3A fast-blow fuse is appropriate for this module. This protects your wiring and power source in the unlikely event of a module failure.
💡 Tip: For automotive installations, use an add-a-fuse adapter to tap into an existing fuse slot in your vehicle's fuse box. Choose a circuit that is only powered when the ignition is on (switched power) so the converter doesn't drain your battery when the vehicle is off.
🔋 Understanding USB-C and Power Delivery Compatibility
This is one of the most important things to understand about this module, so let's break it down clearly.
What This Module Does
This converter outputs a fixed 5V at up to 3A through a USB-C connector. This is the standard USB power level that has been used for charging devices for many years. At 5V × 3A = 15W, it provides a solid amount of power — enough to charge most smartphones, GPS units, dash cams, action cameras, Raspberry Pi boards, and many tablets.
What This Module Does NOT Do
This module does not contain a USB Power Delivery (PD) negotiation chip. Here's what that means in practical terms:
USB Power Delivery (PD) is a communication protocol built into many modern chargers and devices. When you plug a PD-capable device into a PD-capable charger, they have a brief "conversation" over the USB-C cable's CC (Configuration Channel) pins. The device tells the charger what voltages and currents it can accept (for example, 9V/2A, 15V/3A, or 20V/5A), and the charger agrees to supply one of those levels. This is how fast charging works — by negotiating a higher voltage than the standard 5V.
Since this module has no PD chip, that negotiation never happens. The module simply provides 5V on the USB-C power pins.
What Happens When There's No PD Negotiation
When a PD-capable device is plugged into this module and doesn't receive a PD response, it will typically default to the USB baseline current limit, which is usually 0.5A to 0.9A (2.5W to 4.5W) depending on the device. This is a safety behavior built into the USB-C specification — when a device can't confirm the source's capabilities through PD negotiation, it plays it safe and limits its current draw to avoid overloading an unknown source.
This means that even though this module is capable of delivering 3A, a PD-dependent device may only draw a fraction of that. The module isn't limiting the current — the device itself is choosing to draw less because it can't verify what the source can safely provide. The result is that the device will charge, but very slowly — or in the case of power-hungry devices like laptops, it may not charge at all.
Devices that do not rely on PD negotiation — such as most dash cams, GPS units, action cameras, and many phones — will draw current normally up to the module's 3A limit and charge at full speed.
Compatibility Quick Reference
| Device Type | Will It Charge? | Notes |
|---|---|---|
| Most Android phones | Yes | Charges at standard 5V speed (not fast charge). Most Android phones accept 5V USB charging without requiring PD negotiation. |
| iPhones (iPhone 8 and later) | Yes | Charges at standard 5V speed. iPhones accept 5V charging — PD is only needed for fast charging at higher wattages. |
| Dash cams | Yes | Most dash cams are designed for 5V USB power and work perfectly with this module. |
| GPS units | Yes | Standard 5V USB devices — fully compatible. |
| Action cameras (GoPro, etc.) | Yes | These typically charge at 5V and work well with this module. |
| Raspberry Pi / Arduino | Yes | 5V 3A is the recommended power supply for Raspberry Pi 4 and similar boards. |
| USB-C LED lights and fans | Yes | Simple 5V USB accessories work without any negotiation. |
| Tablets (iPad, Samsung Tab, etc.) | Usually yes, slowly | Most tablets will accept 5V charging but may default to baseline current (0.5–0.9A) if they expect PD. Charging will be very slow, and large tablets may only maintain charge rather than gain charge while in use. |
| USB-C laptops | No | Laptops that charge via USB-C require PD negotiation at higher voltages (typically 20V). They will not charge from this module. |
| Nintendo Switch (docked mode) | No | The Switch dock requires PD negotiation at 15V. Handheld mode may charge very slowly at baseline current. |
| Devices requiring Qualcomm Quick Charge | Usually yes, slowly | QC devices will fall back to standard 5V charging. They will charge, but not at Quick Charge speeds, and may limit current draw to baseline levels. |
💡 Tip: A simple rule of thumb: if your device came with a charger rated at 5V (or if it charges fine from a standard USB port on a computer), it will work great with this module. If your device's charger is rated at 9V, 12V, 15V, or 20V and uses PD or Quick Charge, this module will either charge it very slowly at baseline current or not at all.
Why Not Just Add a PD Chip?
You might wonder why this module doesn't include PD negotiation. The answer is simplicity and reliability. A PD controller adds complexity, cost, and potential points of failure. For the vast majority of use cases — charging a phone in a car, powering a dash cam, running a Raspberry Pi from a 12V battery — a straightforward 5V 3A supply is exactly what's needed. It's a purpose-built tool that does one job very well.
🔧 How It Works
This module uses a synchronous buck converter topology to step down the input voltage to 5V. Here's a simplified explanation of what's happening inside:
- The input DC voltage (8–23V) enters the module through the red and black wire leads.
- A switching transistor rapidly turns on and off (typically at hundreds of kilohertz), chopping the input voltage into pulses.
- An inductor and capacitor smooth those pulses into a steady 5V DC output.
- A feedback circuit continuously monitors the output voltage and adjusts the switching to maintain a stable 5V regardless of input voltage changes or load variations.
- The regulated 5V is delivered through the USB-C connector to your device.
Because the converter is a switching design rather than a linear design, the excess voltage is not wasted as heat. Instead, the converter trades voltage for current — a lower output voltage means a higher output current is available from a given input power. This is why the module can deliver 3A at 5V from only about 1.25A at 12V input.
Non-Isolated Topology
This module uses a non-isolated design, which means the input ground and output ground are electrically connected. For most applications (vehicles, batteries, solar systems), this is perfectly fine and is actually the most common design for DC-DC converters in this power range. However, it means you should not use this module in applications where the input and output grounds must be kept separate (galvanically isolated).
🎯 Common Applications
- Vehicle Phone Charging — Charge your phone from a 12V car, truck, motorcycle, ATV, or RV electrical system
- Dash Cam Power — Provide clean, stable 5V power to a USB-C dash cam hardwired into your vehicle
- Marine Electronics — Power USB devices on boats from the 12V house battery, with full waterproof protection
- Solar and Off-Grid Systems — Convert 12V solar battery bank output to 5V USB for charging devices at a campsite or cabin
- Raspberry Pi / Single-Board Computers — Power a Raspberry Pi 4 or similar board from a 12V battery for remote or mobile projects
- GPS and Navigation — Hardwire a GPS unit into a vehicle or boat electrical system
- Action Cameras — Provide continuous power to a GoPro or similar camera for extended recording
- LED Lighting and USB Accessories — Power 5V USB LED strips, fans, or other accessories from a 12V system
🔋 Power and Efficiency
Input Current Draw
Because this is a switching converter, the input current is lower than the output current. The module converts voltage down while stepping current up (minus efficiency losses). Here are some typical input current values:
| Input Voltage | Output Load | Approximate Input Current |
|---|---|---|
| 12V | 3A (15W full load) | ~1.5A |
| 12V | 2A (10W) | ~1.0A |
| 12V | 1A (5W) | ~0.5A |
| 15V | 3A (15W full load) | ~1.2A |
| 20V | 3A (15W full load) | ~0.9A |
💡 Tip: These values assume approximately 85% efficiency. Actual input current will vary slightly depending on the specific input voltage and load conditions.
No-Load Power Consumption
The module draws less than 100mA from the input when no device is connected to the USB-C output. On a 12V system, this is about 1.2W of standby power. If you're concerned about battery drain (for example, on a vehicle that sits unused for extended periods), consider adding a switch to the input circuit or connecting to a switched power source that turns off with the ignition.
🛠️ Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Device doesn't charge at all | Device requires PD negotiation at a higher voltage | This module outputs 5V only without PD. USB-C laptops and some tablets require PD negotiation at higher voltages and will not charge from this module. Check the compatibility table above. |
| Device charges very slowly | Device defaulting to USB baseline current | Without PD negotiation, many devices limit themselves to 0.5–0.9A as a safety precaution. This is normal behavior — the device is protecting itself from an unknown source. The module can deliver 3A, but the device is choosing not to draw it. |
| No output at all | Input voltage too low or too high | Verify input voltage is between 8V and 23V DC. Below 8V, the module may not operate. Above 23V, over-voltage protection may activate. |
| No output at all | Reversed polarity | Check that red wire is connected to positive (+) and black wire to negative (−). Reversed polarity may have damaged the module. |
| No output at all | Blown input fuse | If you installed an inline fuse, check whether it has blown. Replace with the same rating. |
| Output cuts out intermittently | Loose wire connections | Check all connections. Vibration in vehicles can loosen wire nuts or poor crimps. Re-secure with proper crimp connectors or solder joints. |
| Output cuts out intermittently | Over-current protection activating | Your device may be drawing more than 3A momentarily. The module's protection will cut output and auto-recover. If this happens frequently, the device may not be suitable for this module. |
| Module feels warm | Normal operation under load | Some warmth is normal, especially at higher loads. The module is rated for operation up to 60°C ambient temperature. Ensure adequate airflow around the module. |
⚠️ Important Notes
- Do not exceed 23V input. Input voltage above 23V DC may damage the module and is outside the rated operating range.
- Do not reverse polarity. Always connect red to positive and black to negative. Reversed connections can permanently damage the module.
- This module does not support USB data. It provides power only through the USB-C connector. It cannot be used for data transfer, video output, or any other USB data function.
- Non-isolated design. The input and output grounds are electrically connected. Do not use in applications requiring galvanic isolation between input and output.
- No PD negotiation. This module will not fast-charge devices that require USB Power Delivery negotiation. Devices expecting PD may default to USB baseline current (0.5–0.9A) rather than drawing the full 3A available.
- Waterproof rating applies to the module body only. The USB-C connector end is not waterproof when exposed. In wet environments, ensure the USB-C connection point is protected from water ingress.
- Operating temperature range is -25°C to +60°C. Avoid mounting the module directly on engine blocks or in locations that exceed this range.
- Secure all wire connections properly. In vehicle and marine applications, vibration can loosen connections over time. Use crimp connectors, solder with heat shrink, or screw terminals — not wire nuts or tape alone.
🏪 Where to Buy the F23J5V3A1S-C 12V to 5V 3A DC-DC Converter
Buy the F23J5V3A1S-C 12V to 5V 3A DC-DC Converter with USB-C Output →
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📚 Resources & Downloads
- 3D Mechanical Drawing (PDF): Download Mechanical Drawing
- STEP File (3D CAD Model): Download STEP File
- All DC-DC Converter User Guides: All Buck DC-DC Converter User and Hookup Guides
This guide is provided by Envistia Mall for educational and technical reference purposes. The manufacturer and Envistia LLC (dba Envistia Mall) are not responsible for any damages or losses resulting from the use of this product. Always follow proper electrical safety practices when working with electronic components. Specifications are based on manufacturer data and are subject to change without notice.