PM6680 STMicroelectronics, PM6680 Datasheet - Page 39
PM6680
Manufacturer Part Number
PM6680
Description
IC CTRLR DUAL STEP DOWN 32VFQFPN
Manufacturer
STMicroelectronics
Datasheet
1.PM6680TR.pdf
(49 pages)
Specifications of PM6680
Applications
Controller, Notebook Power System
Voltage - Input
6 ~ 28 V
Number Of Outputs
2
Voltage - Output
0.9 ~ 5.5 V
Operating Temperature
0°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
32-VFQFN, 32-VFQFPN
Output Voltage
5 V, 0.9 V to 5.5 V, 0.9 V to 3.3 V
Output Current
0.33 A
Input Voltage
5.5 V to 28 V
Mounting Style
SMD/SMT
Maximum Operating Temperature
+ 125 C
Minimum Operating Temperature
- 10 C
For Use With
497-6379 - BOARD EVALUATION FOR PM6680A497-6378 - BOARD EVALUATION FOR PM6680497-6425 - BOARD EVAL BASED ON PM6680A
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
PM6680
Manufacturer:
STMicroelectronics
Quantity:
135
Company:
Part Number:
PM6680
Manufacturer:
INFIONEON
Quantity:
1
Company:
Part Number:
PM6680ATR
Manufacturer:
STMicroelectronics
Quantity:
10 000
Company:
Part Number:
PM6680TR
Manufacturer:
st
Quantity:
1 050
PM6680
The T node voltage is the sum of the output voltage and the triangular waveform generated
by the virtual ESR network. In fact the virtual ESR network behaves like a further equivalent
ESR R
A good trade-off is to design the network in order to achieve an R
Equation 28
where ∆I
voltage. It should be chosen higher than approximately 30 mV.
The new closed loop gain depends on C
that:
Equation 29
Where:
Equation 30
where R
given by the virtual ESR network R
Moreover C
Equation 31
Where k is a free design parameter greater than 3 and determines the minimum integrator
capacitor value C
Equation 32
C must be selected as shown:
Equation 33
ESR
TOT
L
is the inductor current ripple and V
.
INT
is the sum of the ESR of the output capacitor Rout and the equivalent ESR
must meet the following condition:
INT
:
f
C
sw
INT
>
C
ESR
R
f
Z
k
INT
>
ESR
×
=
2
.
f
π
C
>
2
Z
INT
=
π
×
2
=
>
V
×
⎛
⎜ ⎜
⎝
. In order to ensure stability it must be verified
π
g
g
RIPPLE
5
2
f
C
sw
∆
RIPPLE
k
×
m
m
π
×
I
out
L
f
×
Z
C
1
−
C
INT
×
×
f
Z
−
out
R
V
⎞
⎟ ⎟
⎠
k
is the overall ripple of the T node
R
Vr
TOT
OUT
×
×
out
V
R
Vr
OUT
TOT
ESR
given by:
Device description
39/49