PM6680ATR STMicroelectronics, PM6680ATR Datasheet - Page 37
PM6680ATR
Manufacturer Part Number
PM6680ATR
Description
IC CTRLR DUAL STEP DOWN 32VFQFPN
Manufacturer
STMicroelectronics
Datasheet
1.PM6680ATR.pdf
(48 pages)
Specifications of PM6680ATR
Applications
Controller, Embedded Computer System
Voltage - Input
6 ~ 36 V
Number Of Outputs
2
Voltage - Output
0.9 ~ 5 V
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
32-VFQFN, 32-VFQFPN
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
Other names
497-6896-2
PM6680ATR
PM6680ATR
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
PM6680ATR
Manufacturer:
STMicroelectronics
Quantity:
10 000
PM6680A
Figure 37. Virtual ESR network
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.
A good trade-off is to design the network in order to achieve an R
Equation 28
where ∆IL is the inductor current ripple and V
voltage. It should be chosen higher than approximately 30 mV.
The new closed loop gain depends on C
that:
Equation 29
Where:
∆V
∆V
Output
Output
voltage
voltage
D
D
D
D
∆V
∆V
t
t
1
1
R1
R1
R1
R1
C
C
C
C
T node
T node
voltage
voltage
L
L
L
L
T
T
R
R
R
R
t
t
R
R
C
C
R
R
C
C
R
COMP pin
COMP pin
voltage
voltage
C
R
R
R
R
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
ESR
INT
C
C
INT
INT
C
C
INT
INT
Vr
Vr
FILT
FILT
FILT
FILT
>
INT.
=
2
V
π
t
t
g
RIPPLE
In order to ensure stability it must be verified
∆
×
RIPPLE
m
I
f
L
∆V
∆V
C
C
C
C
Z
INT
INT
INT
INT
×
1
1
R
R
R
R
R
R
R
R
R
R
R
R
−
V
2
2
2
1
1
1
2
2
2
1
1
1
COMP
COMP
COMP
COMP
Vr
is the overall ripple of the T node
OUT
R
OU
OU
T
T
OU
OU
T
T
out
FB
FB
FB
FB
Vr
Vr
Vr
Vr
gm
gm
gm
gm
ESR
+
+
V1
V1
V1
V1
given by:
Vr
Vr
Vr
Vr
Design guidelines
+
+
Comparator
Comparator
Comparator
Comparator
-
-
PWM
PWM
PWM
PWM
37/48