EVALPM6680A STMicroelectronics, EVALPM6680A Datasheet - Page 37
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
PM6680A
Figure 37. Virtual ESR network
The T node voltage is the sum of the output voltage and the triangular waveform generated
by the virtual ESR network. In fact the virtual ESR network behaves like a further equivalent
ESR.
A good trade-off is to design the network in order to achieve an R
Equation 28
where ∆IL is the inductor current ripple and V
voltage. It should be chosen higher than approximately 30 mV.
The new closed loop gain depends on C
that:
Equation 29
Where:
∆V
∆V
Output
Output
voltage
voltage
D
D
D
D
∆V
∆V
t
t
1
1
R1
R1
R1
R1
C
C
C
C
T node
T node
voltage
voltage
L
L
L
L
T
T
R
R
R
R
t
t
R
R
C
C
R
R
C
C
R
COMP pin
COMP pin
voltage
voltage
C
R
R
R
R
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
ESR
INT
C
C
INT
INT
C
C
INT
INT
Vr
Vr
FILT
FILT
FILT
FILT
>
INT.
=
2
V
π
t
t
g
RIPPLE
In order to ensure stability it must be verified
∆
×
RIPPLE
m
I
f
L
∆V
∆V
C
C
C
C
Z
INT
INT
INT
INT
×
1
1
R
R
R
R
R
R
R
R
R
R
R
R
−
V
2
2
2
1
1
1
2
2
2
1
1
1
COMP
COMP
COMP
COMP
Vr
is the overall ripple of the T node
OUT
R
OU
OU
T
T
OU
OU
T
T
out
FB
FB
FB
FB
Vr
Vr
Vr
Vr
gm
gm
gm
gm
ESR
+
+
V1
V1
V1
V1
given by:
Vr
Vr
Vr
Vr
Design guidelines
+
+
Comparator
Comparator
Comparator
Comparator
-
-
PWM
PWM
PWM
PWM
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