PM6670S STMicroelectronics, PM6670S Datasheet - Page 27

• Manufacturer Part Number: PM6670S
• Description: IC CTLR DDR2/3 MEM PS VFQFPN-24
• Manufacturer: STMicroelectronics

Specifications of PM6670S

• Applications: Memory, DDR2/DDR3 Regulator
• Current - Supply: 800µA
• Voltage - Supply: 4.5 V ~ 36 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-VFQFN, 24-VFQFPN
• For Use With: 497-8411 - BOARD EVAL PM6670S DDR2/3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PM6670S
Equation 14
Moreover, the C
Equation 15
where R
the Virtual-ESR Network (R
determines the minimum integrator capacitor value C
Equation 16
The capacitor of the virtual-ESR Network, C, is chosen as follows:
Equation 17
and R is calculated to provide the desired triangular ripple voltage:
Equation 18
Finally the R1 resistor is calculated according to expression 19:
Equation 19
TOT
is the sum of the ESR of the output capacitor and the equivalent ESR given by
INT
capacitor must meet the following condition:
VESR
Doc ID 14432 Rev 4
C
f
SW
). The k parameter must be greater than unity (k > 3) and
INT
R
TOT
>
R
>
k
1
R
2
⋅
= ESR + R
=
f
⋅ π
C
Z
=
R
R
>
=
⎛
⎜
⎝
R
⋅
f
5
−
g
⎛
⎜ ⎜
⎝
SW
2
VESR
k
m
C
⋅
⋅ π
C
C
L
⋅
−
⋅
C
INT
⋅ π
1
⋅ π
1
⋅
f
out
VESR
Z
C
f
k
Z
f
⎞
⎟
⎠
Z
INT
⋅
⋅
⎞
⎟ ⎟
⎠
R
Vout
TOT
Vr
:
Device description
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