STEVAL-ISA051V2 STMicroelectronics, STEVAL-ISA051V2 Datasheet - Page 48

• Manufacturer Part Number: STEVAL-ISA051V2
• Description: BOARD EVAL PM6670AS DDR2/3
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of STEVAL-ISA051V2

• Design Resources: STEVAL-ISA051V2 Gerber Files STEVAL-ISA051V2 Schematic STEVAL-ISA051V2 Bill of Material
• Main Purpose: Special Purpose DC/DC, DDR Memory Supply
• Outputs And Type: 4, Non-Isolated
• Voltage - Output: 1.5V, 1.8V
• Voltage - Input: 4.5 ~ 36V
• Regulator Topology: Buck
• Board Type: Fully Populated
• Utilized Ic / Part: PM6670A
• Input Voltage: 4.5 V to 36 V
• Output Voltage: 1.8 V, 1.5 V
• Product: Power Management Modules
• Silicon Manufacturer: ST Micro
• Silicon Core Number: PM6670AS
• Kit Application Type: Power Management
• Application Sub Type: DDR2/3 Memory Power Supply Controller
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: PM6670AS
• Other names: 497-8412

Application information
48/53
If the ripple on pin COMP is greater than the integrator output dynamic (150 mV), an
additional capacitor C
attenuation factor of the output ripple, select:
Equation 50
In order to reduce noise on pin COMP, it's possible to introduce a resistor R
with C
greater (10 or more times) than the switching frequency of the section:
Equation 51
For most of applications both R
If the ripple is very small (e.g. such as with ceramic capacitors), an additional compensation
network, called “Virtual ESR” network, is needed. This additional part generates a triangular
ripple that substitutes the ESR output voltage ripple. The complete compensation scheme is
represented in
Figure 41. Virtual ESR network
INT
Generation
Block
and C
Ton
Figure 41
filt
, becomes a low psas filter. The cutoff frequency f
filt
could be added in order to reduce its amplitude. If q is the desired
.
PWM Comparator
Doc ID 14436 Rev 2
INT
R
+
INT
-
and C
C
=
filt
2
VREF
⋅ π
filt
=
f
C
CUT
are unnecessary.
INT
C
C
⋅
q
1
1 (
INT
INT
R
−
INT
C
+
C
) q
⋅
FILT
C
INT
C
FILT
FILT
Integrator
g
R
m
+
-
CUT
L
C
R1
0.9V
must be much
INT
that, together
PM6670AS
VDDQ