EVALPM6680 STMicroelectronics, EVALPM6680 Datasheet - Page 40
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EVALPM6680
Manufacturer Part Number
EVALPM6680
Description
BOARD EVALUATION FOR PM6680
Manufacturer
STMicroelectronics
Datasheet
1.PM6680TR.pdf
(49 pages)
Specifications of EVALPM6680
Mfg Application Notes
PM6680 Eval Kit, AN2566 App Note
Main Purpose
DC/DC, Step Down with LDO
Outputs And Type
3, Non-Isolated
Power - Output
13.25W
Voltage - Output
1.05V, 1.5V, 5V
Current - Output
5A, 5A, 100mA
Voltage - Input
6 ~ 28V
Regulator Topology
Buck
Frequency - Switching
200kHz, 300kHz
Board Type
Fully Populated
Utilized Ic / Part
PM6680
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
497-6241
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Device description
7.13.7
40/49
R must be chosen in order to have enough ripple voltage on integrator input:
Equation 34
R1 can be selected as follows:
Equation 35
Example:
OUT1 = 1.5 V, f
We design R
R
(eq.36).
Other parts design
●
Figure 38. VIN pin filter
●
INT
VIN filter
A VIN pin low pass filter is suggested to reduce switching noise. The low pass filter is
shown in the next figure:
Typical components values are: R = 3.9 Ω and C = 4.7 uF.
VCC filter
A VCC low pass filter helps to reject switching commutations noise:
= 1 kΩ by eq.27, 28. C = 5.6 nF by Eq.34. Then R = 36 kΩ (eq.35) and R1 = 3 kΩ
ESR
SW
= 12mW. We choose C
= 290 kHz, L = 2.5 uH, C
Input
voltage
R
R
R
C
C
1
=
R
INT
R
=
R
×
R
−
1
= 1nF by equations 30, 33 and C
1
out
⎛
⎜ ⎜
⎝
ESR
0
0
C
C
0
0
L
= 330 uF with R
p
p
×
×
×
F
F
π
π
1
1
C
×
×
f
f
Z
Z
V
V
⎞
⎟ ⎟
⎠
I
I
N
N
out
≈
12 mΩ.
filt
= 47 pF,
PM6680