Datasheet
VIN = 8 - 17 V
VOUT = 3.3 V, 6 A
R5
10.0k
C7
100uF
C3
0.1uF
R6
2.21k
R4
3.74k
C4
0.01uf
C5
47pF
C1
10uF
R1
35.7k
R2
8.06k
R3
100k
1
RT/CLK
2
GND
3
GND
4
PVIN
5
PVIN
6
VIN
7
V_SNS
8
COMP
9
SS/TR
10
EN
11
PH
12
PH
13
BOOT
14
PWRGD
15
PWPD
U1
TPS54622RHL
C2
4.7uF
C6
0.022uf
C8
Optional
L1
3.3uH
EN
V_SNS
V_SNS
EN
VIN
VOUT
TPS54622
SLVSA70B –MARCH 2011–REVISED JANUARY 2014
www.ti.com
APPLICATION INFORMATION
Design Guide – Step-By-Step Design Procedure
This example details the design of a high frequency switching regulator design using ceramic output capacitors.
A few parameters must be known in order to start the design process. These parameters are typically determined
at the system level. For this example, we start with the following known parameters:
Table 1.
Parameter Value
Output Voltage 3.3 V
Output Current 6 A
Transient Response 1A load step ΔVout = 5 %
Input Voltage 12 V nominal, 8 V to 17 V
Output Voltage Ripple 33 mV p-p
Start Input Voltage (Rising Vin) 6.528 V
Stop Input Voltage (Falling Vin) 6.190 V
Switching Frequency 480 kHz
Typical Application Schematic
The application schematic of Figure 29 was developed to meet the requirements above. This circuit is available
as the TPS54622EVM-012 evaluation module. The design procedure is given in this section. For more
information about Type II and Type III frequency compensation circuits, see Designing Type III Compensation for
Current Mode Step-Down Converters (SLVA352) and Design Calculator (SLVC219).
Figure 29. Typical Application Circuit
Operating Frequency
The first step is to decide on a switching frequency for the regulator. There is a trade off between higher and
lower switching frequencies. Higher switching frequencies may produce smaller a solution size using lower
valued inductors and smaller output capacitors compared to a power supply that switches at a lower frequency.
However, the higher switching frequency causes extra switching losses, which hurt the converter’s efficiency and
thermal performance. In this design, a moderate switching frequency of 480 kHz is selected to achieve both a
small solution size and a high efficiency operation.
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