ACPPSv1 Automotive Computer Peripheral Power Supply - $80(US)

This series of computer synchronized DC-DC power supplies are specifically designed to operate in an automotive environment. The most common use is powering USB hubs and LCD displays in Car-PC applications. There are several key design features that separate the ACPPS from other Point of Load (POL) power supplies aimed at the Car-PC market: Form, Power, Efficiency, Frequency and Control.

Form: Many other available POL devices are not finished products. Many come as circuit boards with wires hanging off both ends. In order to use it you must find a way to enclose it, connect it, and mount it. 

The ACPPS has a robust aluminum chassis with mounting tabs, a tough powder coat finish, and screw terminal electrical connections. Servicing and modifying your Car-PC install will be far less painful with this professionally designed product.

Power: At 8A the ACPPSv1.03 is one of the most powerful Car-PC POL supplies available on the market. You might not need all that power now, but what if you upgrade? Will you have to add another POL later to keep your system happy?

Efficiency: The ACPPSv1 is capable of operating above 90% efficiency through most of its rated range.

Efficiency isn’t important in a car where electrical power is abundant, right?

• What if you want to operate on battery? Higher efficiency means longer operating time while running on batteries.
• What about heat build up? If a device isn’t efficient it generates more heat, often requiring a fan. Fans draw power, generate audible noise, require intake and exhaust ducts and have moving parts that will eventually fail possibly causing the device to overheat and fail. It's better to not need a fan at all.

Frequency: Other POL devices operate at much lower switching frequencies because it's cheaper, which in turn negatively impacts efficiency and overall size. The ACPPS line operates at frequencies higher than 300kHz keeping them small and efficient. Another benefit to higher switching frequencies is less audible switching noise. If you are using a USB sound card in your Car-PC install, you may have issues with noise coming from a cheaper POL supply. At 300 kHz, the noise from the ACPPS is well above the range of human hearing.

Control: The ACPPS has two enable inputs that control when it turns on and off, USB enable and remote enable (RE). Both input operate the same; apply a 5-20V signal and the ACPPS turns on, much the same way a car amplifier works. The USB enable input is a voltage monitor that checks the state of the PC it is connected to. The ACPPS is not an actual USB device, so no drivers are needed and no computer resources are used. When the computer turns on so does the ACPPS, and when it turns off the ACPPS follows.

ACPPSv1 User Manual

Detailed design specifications:

• Input range: 9-20V
• Temperature Range: -40C to 50C
• Output 1: 5V +/- 2%, 0-8A (stable with no load)
• Output 2: Unregulated 12v (Input voltage), 0-5A
• Output 1 Ripple Voltage: 30mV @ 25C (125mV @ -40C)
• Efficiency: up to 94%
• Topology: Voltage mode switching power supply
• Dimensions: 5.5" x 3.3" x 1.25"

Key features:

• Accessory 12V output at rated at 5A (unregulated)
• Power supply can be enabled by USB cable or RE input
• Easily accessible 15A ATC Fuse (standard automotive blade fuse)
• Extruded aluminum chassis, powder coated black with mounting
• 5V output on LED (Blue)
• Screw terminals for power connections, each rated at 15A
• Electrically floating chassis