STEVAL-ISA051V2 STMicroelectronics, STEVAL-ISA051V2 Datasheet - Page 25

• 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

PM6670AS
Equation 7
where gm = 50 μs is the integrator trans conductance.
In order to ensure stability it must be also verified that:
Equation 8
If the ripple on the COMP pin is greater than the integrator 150 mV, the auxiliary capacitor
C
by:
Equation 9
In order to reduce the noise on the COMP pin, it is possible to add a resistor R
together with CINT and C
much greater (10 or more times) than the switching frequency:
Equation 10
If the ripple is very small (lower than approximately 20 mV), a different compensation
network, called “Virtual-ESR” Network, is needed. This additional circuit generates a
triangular ripple that is added to the output voltage ripple at the input of the integrator. The
complete control scheme is shown in
FILT
can be added. If q is the desired attenuation factor of the output ripple, C
FILT
, becomes a low pass filter. The cutoff frequency f
Doc ID 14436 Rev 2
C
R
INT
INT
C
>
C
INT
=
FILT
Figure 30
2
2
⋅ π
⋅ π
>
⎛
⎜
⎝
=
2
f
CUT
f
⋅ π
SW
C
k
g
g
INT
m
f
m
Zout
⋅
−
.
C
C
1
f
⋅
q
Zout
INT
1 (
INT
⋅
V
−
+
Vr
OUT
⎞
⎟
⎠
⋅
) q
C
C
⋅
FILT
Vout
FILT
Vr
Device description
FILT
INT
CUT
that,
is given
must be
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