STEVAL-ISA053V1 STMicroelectronics, STEVAL-ISA053V1 Datasheet - Page 37

• Manufacturer Part Number: STEVAL-ISA053V1
• Description: BOARD EVALUATION FOR PM6680
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of STEVAL-ISA053V1

• Design Resources: STEVAL-ISA053V1 Gerber Files PM6680 Eval Kit Schematic STEVAL-ISA053V1 Bill of Material
• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 3, Non-Isolated
• 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
• Input Voltage: 6 V to 28 V
• Output Voltage: 5 V
• Product: Power Management Modules
• Silicon Manufacturer: ST Micro
• Silicon Core Number: PM6680
• Kit Application Type: Power Management - Voltage Regulator
• Application Sub Type: Step Down DC/DC Controller
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: PM6680
• Other names: 497-6378

PM6680
7.13.6
Closing the integrator loop
The design of external feedback network depends on the output voltage ripple. If the ripple
is higher than approximately 30 mV, the feedback network (
keep the loop stable.
Figure 36. Circuitry for output ripple compensation
The stability of the system depends firstly on the output capacitor zero frequency. The
following condition should be satisfied:
Equation 23
where k is a design parameter greater than 3 and R
determinates the minimum integrator capacitor value C
Equation 24
where gm = 50 us is the integrator transconductance.
In order to ensure stability it must be also verified that:
Equation 25
OUTPUT
VOLTAGE
Vr
t
COMP PIN
VOLTAGE
D
D
? V
f
L
L
t
sw
C
INT
C
C
R
R
? V
C
>
O
O
O
O
U
U
U
U
INT
k
>
C
C
T
T
T
T
F
F
×
I
I
C
C
R
R
2
L
L
T
T
I
I
I
I
f
N
N
N
N
π
>
Zout
T
T
T
T
×
2
⎛
⎜
⎝
π
f
=
sw
g
×
g
k
V
V
m
m
f
C
C
C
2
C
R
R
R
R
Zout
I
−
O
O
I
N
N
2
1
π
2
1
M
M
T
T
O
O
f
P
P
×
Zout
U
U
T
T
C
×
F
F
B
B
out
out
⎞
⎟
⎠
V
k
×
Vr
OUT
I=gm(V1-Vr)
is the ESR of the output capacitor. It
INT
×
V
V
V
R
Vr
OUT
r
r
:
g
out
g
Figure 35
m
m
+
V
V
1
1
V
V
r
r
+
C
C
-
o
) is usually enough to
o
m
m
P
P
p
p
W
W
Device description
a
a
M
M
r
r
a
a
t
t
o
o
r
r
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