Summary of Switch Mode Power Supply (SMPS) Topologies (Part I)
### Summary This article introduces Switch Mode Power Supply (SMPS) topologies, driven by the demand for smaller and more efficient electronics. It explains the fundamental concept of DC-to-DC conversion using a conceptual diagram where output voltage is regulated by varying series resistance or shunt current. The text highlights that controlling current while keeping resistance constant results in power loss, defining this as a shunt-controlled regulator. This guide aims to help users select appropriate SMPS topologies and components.
Parts used in the SMPS Topologies Project:
- Switch Mode Power Supply (SMPS)
- DC-to-DC converter
- Load (RL)
- Primary voltage source (VIN)
- Output voltage (VOUT)
- Series resistor (RS)
- Shunt current (IS)
- Shunt-controlled regulator
he industry drive toward smaller, lighter and more
efficient electronics has led to the development of the
Switch Mode Power Supply (SMPS). There are several
topologies commonly used to implement SMPS.
This application note, which is the first of a two-part
series, explains the basics of different SMPS
topologies. Applications of different topologies and
their pros and cons are also discussed in detail. This
application note will guide the user to select an
appropriate topology for a given application, while
providing useful information regarding selection of
electrical and electronic components for a given SMPS
design.
WHY SMPS?
The main idea behind a switch mode power supply can
easily be understood from t
he conceptual explanation
of a DC-to-DC converter, as shown in Figure 1. The
load, R
L
, needs to be supplied with a constant voltage,
V
OUT
, which is derived from a primary voltage source,
V
IN
. As shown in Figure 1, the output voltage V
OUT
can
be regulated by varying
the series resistor (R
S
) or the
shunt current (I
S
).
When V
OUT
is controlled by varying I
S
and keeping R
S
constant, power loss inside the converter occurs. This
type of converter is known as shunt-controlled
regulator. The power loss inside the converter is given
by Equation 1. Please note that the power los
For more detail: Switch Mode Power Supply (SMPS) Topologies (Part I)
- What drives the development of SMPS?
The industry drive toward smaller, lighter, and more efficient electronics. - How can the output voltage VOUT be regulated?
By varying the series resistor RS or the shunt current IS. - Does varying the shunt current cause power loss?
Yes, when VOUT is controlled by varying IS while keeping RS constant, power loss occurs. - What is a shunt-controlled regulator?
It is a type of converter where output voltage is controlled by varying shunt current with a constant series resistor. - What does this application note explain?
It explains the basics of different SMPS topologies, their applications, pros, and cons. - Can this guide help select components?
Yes, it provides useful information regarding the selection of electrical and electronic components for a given SMPS design. - Is this a complete series on SMPS?
No, this is the first part of a two-part series.
