Incor. User's Guide Buck Converter SLVU013

2-1
Design Procedure
Design Procedure
The SLVP111–114 are dc-dc synchronous buck converter evaluation modules
(EVMs) that provide a regulated output voltage at up to 6 A with a power input
voltage range of 4.5 V to 6 V. A low power 12-V, 20-mA source is also required
to power the TPS56xx controller. The controller operates at a nominal
frequency of 135 kHz for 5 V input and 3.3 V output. To provide the highest level
of performance, the EVM converters use hysteretic , or ripple, control.
Hysteretic-controlled synchronous buck
converters have several advantages
over conventional PWM-controlled power supplies:
 Correction of output voltage variations caused by output-load or input-
voltage transients is extremely fast.
 The user controls output ripple by adjusting the operational parameters of
the converter, instead of relying on brute force methods requiring the
choice of an output filter.
 Hysteretic control sets the operational frequency of the converter. For a
given set of external components, the lower the permissible ripple setting,
the higher the operational frequency.
 There is no control loop to design.
Topic Page
2.1 TPS56xx Functions 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 External Component Selection 2–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 2