This site is dedicated to a review of regulated 5-volt DC power supplies capable of delivering up to 3-amps of current. This power specification is similar to that delivered by the USB Type-C standard.

The original motivation for the site is to assess the ability of these designs to operate safely in environments where noise immunity and reliability are key aspects of operation.

Reference Design, Some Lagging Interfaces

The results posted on this site are preliminary and have not yet been verified through background theory, nor have they been implemented or applied in any environment that can validate their fitness for use. Details of the design are limited to this Paper Study of a 5-Volt Power Supply Delivering up to 3 Amps of Current

The following are measures of success of the designs being discussed:

1. The load is isolated from and protected against surges and transients that may occur on the unregulated input lines.
2. The unregulated input voltage may vary anywhere from 5.5-V to 36-V DC.
3. The maximum current drawn from the unregulated supply is never more than 3-A.
4. The power supplied by the 5-V output is limited to 15-W (3-A@5-V).
5. The supplied load can enter a low-power state in which power consumption is kept to a minimum.
6. The supplied load does not wake from its low-power state until the regulated voltage and current supply can satisfy minimum values.
7. An orderly transition from operating to low-power state is initiated when the unregulated supply does not have sufficient reserves of power.
8. An abnormal or unexpected variation in the current draw of the supplied load is a fault of the load and it is fair to issue remedial action to protect the faulty components against harm.

The block diagram of the system involves the following components:

1. Unregulated Supply Lines
2. Protective Filtering
3. Regulated DC to DC Converter
4. Power-good Circuitry
5. Load Regulation
6. Load
7. Fault Detection
8. Remedial Actions

The following core concepts are prerequisites to discussions in further sections:

1. Particles
2. Fields
3. Voltage
4. Current
5. Power

The following sections outline the theory of operation behind the core components of the design:

1. Voltage Conversion
2. Surge Suppression
3. Fuses and Relays

The following tools provide a means to model and numerically verify important properties of the design:

1. Conventional DC, Transient and Frequency Domain Analysis

The following list shows a number of readily available reference designs supplied by various power electronics manufacturers:

1. TPS5430EVM-173

This reference design from Texas Instruments has two variants: the first based on the the other based on the TPS5430DDA is validated for an unregulated input voltages from 10-V to 35-V; the other based on the TPS5431DDA is rated for input voltages from 9-V to 21-V

1. STEVAL-ISA208V1

This reference design from STMicro is available in two variants: a low-noise model and a low-consumption model. It is rated for input voltages from Vout to 38V. The design is validated for Vout=5-V or Vout=3.3-V depending on the ratio of the pre-configured resistor values Rfb+ (tied between Vout/Vbias lead pin 6 and FB lead pin 7) and Rfb- (tied between FB lead pin 7 and GND leads pins 13/16). For Rfb+=400K and Rfb-=82K, the output voltage is 5V.

1. TLS4125-5V

This reference design from Infineon is able to provide 2.5A at 5V for a wide rang of input voltages.