EVALPM6680A STMicroelectronics, EVALPM6680A Datasheet - Page 38
EVALPM6680A
Manufacturer Part Number
EVALPM6680A
Description
EVAL BOARD FOR PM6680A
Manufacturer
STMicroelectronics
Datasheet
1.PM6680ATR.pdf
(48 pages)
Specifications of EVALPM6680A
Mfg Application Notes
PM6680A, AN2565 Appl Note
Main Purpose
DC/DC, Step Down with LDO
Outputs And Type
3, Non-Isolated
Power - Output
10.5W
Voltage - Output
1.8V, 3.3V, 5V
Current - Output
2.5A, 2.5A, 100mA
Voltage - Input
6 ~ 36V
Regulator Topology
Buck
Frequency - Switching
200kHz, 300kHz
Board Type
Fully Populated
Utilized Ic / Part
PM6680A
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
497-6263
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Design guidelines
38/48
Equation 30
where R
by the virtual ESR network RESR.
Moreover C
Equation 31
Where k is a free design parameter greater than 3 and determines the minimum integrator
capacitor value C
Equation 32
C must be selected as shown:
Equation 33
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.35).
INT
= 1 kΩ by eq.27, 28. C = 5.6 nF by Eq.34. Then R = 36 kΩ (eq.34) and R1 = 3 kΩ
TOT
INT
is the sum of the ESR of the output capacitor R
ESR
SW
must meet the following condition:
= 12 mΩ. We choose C
INT
= 290 kHz, L = 2.5 µH, Cout = 330 µF with Rout < 12 mΩ.
:
C
f
sw
INT
>
f
R
Z
>
k
1
=
×
2
=
R
f
π
2
C
Z
R
INT
π
×
=
R
=
>
×
×
⎛
⎜ ⎜
⎝
R
−
g
2
5
⎛
⎜ ⎜
⎝
= 1 nF by equations 30, 33 and Cfilt = 47 pF,
f
C
sw
k
ESR
m
π
C
C
×
out
×
L
1
C
×
×
−
C
×
×
INT
π
1
π
f
1
Z
R
out
C
×
×
k
⎞
⎟ ⎟
⎠
TOT
f
f
×
×
Z
Z
R
V
⎞
⎟ ⎟
⎠
Vr
OUT
TOT
out
and the equivalent ESR given
PM6680A