STEVAL-ISA052V1 STMicroelectronics, STEVAL-ISA052V1 Datasheet - Page 26

• Manufacturer Part Number: STEVAL-ISA052V1
• Description: KIT EVAL PM6675S HE CTLR 2A REG
• Manufacturer: STMicroelectronics

Specifications of STEVAL-ISA052V1

• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 2, Non-Isolated
• Voltage - Output: 1.5V, 0.6 ~ 3.3V
• Current - Output: 10A, 2A
• Voltage - Input: 4.5 ~ 28 V
• Regulator Topology: Buck
• Board Type: Fully Populated
• Utilized Ic / Part: PM6675
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-8426

Device description
26/53
Figure 36. "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
another equivalent series resistor R
A good trade-off is to design the network in order to achieve an R
Equation 10
where ∆I
greater than approximately 20 mV.
The new closed-loop gain depends on C
that:
Equation 11
where:
Equation 12
and:
T NODE
VOLTAGE
L
is the inductor current ripple and V
∆V
1
OUTPUT
VOLTAGE
R
R
∆V
T
COMP PIN
VOLTAGE
t
V
REF
C
R
C
R
R
R
1
1
INT
INT
R
VESR
t
VESR
C
f
Z
INT
C
C
=
INT
INT
.
INT
2
=
>
⋅ π
V
. In order to ensure stability it must be verified
2
COMP
COMP
RIPPLE
g
⋅ π
C
ESR
ESR
C
C
t
RIPPLE
∆
VSNS
VSNS
m
out
OUT
∆V
OUT
I
C
C
f
L
1
Z
FILT
2
FILT
⋅
⋅
R
Vout
−
Vr
TOT
is the total ripple at the T node, chosen
ESR
I=g
m
Vr
Vr
(V
1
-Vr)
R
R
Fb2
Fb2
g
g
V
V
m
m
VESR
1
1
V
+
V
REF
REF
R
R
Fb1
Fb1
given by:
+
Comparator
-
Comparator
PWM
PWM
PM6675S