STEVAL-ISA052V2 STMicroelectronics, STEVAL-ISA052V2 Datasheet - Page 22

• Manufacturer Part Number: STEVAL-ISA052V2
• Description: BOARD EVAL BASED ON PM6675A
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of STEVAL-ISA052V2

• Design Resources: STEVAL-ISA052V2 Gerber Files STEVAL-ISA052V2 Schematic STEVAL-ISA052V2 Bill of Material
• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 2, Non-Isolated
• Voltage - Output: 1.5V, 0.6 ~ 3.3V
• Voltage - Input: 4.5 ~ 36 V
• Regulator Topology: Buck
• Board Type: Fully Populated
• Utilized Ic / Part: PM6675AS
• Input Voltage: 4.5 V to 36 V
• Output Voltage: 1.5 V
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed
• For Use With/related Products: PM6675AS
• Other names: 497-8413

Device description
22/48
Figure 26. "Virtual-ESR" network
The ripple on the COMP pin is the sum of the output voltage ripple and the triangular ripple
generated by the Virtual-ESR Network. In fact the Virtual-ESR Network behaves like a
further equivalent series resistor RVESR.
A good trade-off is to design the network in order to achieve an RVESR given by:
Equation 10
where ∆IL is the inductor current ripple and VRIPPLE is the total ripple at the T node,
chosen greater than approximately 20 mV.
The new closed-loop gain depends on C
that:
Equation 11
where:
Equation 12
T NODE
VOLTAGE
ΔV
1
OUTPUT
VOLTAGE
R
R
ΔV
T
COMP PIN
VOLTAGE
t
V
REF
C
R
C
R
R
R
1
1
I
I
N
N
T
T
R
t
VESR
C
f
Z
C
C
INT
=
I
I
N
N
INT
T
2
T
>
=
⋅ π
2
V
. In order to ensure stability it must be verified
C
C
⋅ π
C
E
C
RIPPLE
g
E
C
t
∆
V
V
O
m
O
out
S
S
O
ΔV
O
I
C
C
S
S
f
L
1
M
Z
M
U
U
R
R
N
N
F
F
2
⋅
T
T
P
P
⋅
R
I
I
S
S
L
L
Vout
−
T
T
TOT
Vr
ESR
I=g
m
V
V
(V
r
r
1
-Vr)
R
R
F
F
g
g
b
b
V
V
2
2
m
m
1
1
+
V
V
R
R
E
E
R
F
F
R
F
F
b
b
1
1
+
C
-
C
o
o
m
m
P
P
PM6675AS
p
W
W
p
a
a
M
M
r
r
a
a
t
t
o
o
r
r