Electronic Components Datasheet Search
  English  ▼

X  

SS6845G Datasheet(PDF) 10 Page - Silicon Standard Corp.

Part # SS6845G
Description  Regulated 5V Charge Pump
PDF  13 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  SSC [Silicon Standard Corp.]
Direct Link  http://www.siliconstandard.com
Logo SSC - Silicon Standard Corp.

SS6845G Datasheet(HTML) 10 Page - Silicon Standard Corp.

Back Button SS6845G Datasheet HTML 5Page - Silicon Standard Corp. SS6845G Datasheet HTML 6Page - Silicon Standard Corp. SS6845G Datasheet HTML 7Page - Silicon Standard Corp. SS6845G Datasheet HTML 8Page - Silicon Standard Corp. SS6845G Datasheet HTML 9Page - Silicon Standard Corp. SS6845G Datasheet HTML 10Page - Silicon Standard Corp. SS6845G Datasheet HTML 11Page - Silicon Standard Corp. SS6845G Datasheet HTML 12Page - Silicon Standard Corp. SS6845G Datasheet HTML 13Page - Silicon Standard Corp.  
Zoom Inzoom in Zoom Outzoom out
 10 / 13 page
background image
www.SiliconStandard.com
10 of 13
SS6845G
7/21/2005 Rev.3.01
2. Package Size: A ceramic capacitor with
large volume (0805), gets a lower ESR than
a small one (0603). Therefore, larger devices
provide
improved transient response over
smaller ones.
Table 1 lists the recommended components for
use with the SS6845G.
Table.1 Bill of Material
Design-
ator
Part
Type
Description
Vendor
CIN
2.2
µ
CELMK212BJ-
225MG (X5R)
TAIYO
YUDEN
CFLY
0.22
µ
CEEMK212BJ
-224KG (X7R)
TAIYO
YUDEN
COUT
2.2
µ
CELMK212BJ-
225MG (X5R)
TAIYO
YUDEN
Power Dissipation
Now, le
t’s look at the power dissipation in R DS-ON
and ESR. Assume that the RDS-ON of each internal
switching element in the SS6845G is equal and ESR
is the equivalent series resistance of CFLY (refer
to
Fig. 20 and Fig. 21). The approximation of the
power losses of RDS-ON and ESR are given below:
R
D)
-
D(1
2
I
)
R
D
-
1
2
(
I
)
R
D
2
(
I
D)
-
(1
2R
)
D
-
1
I
(
D
2R
)
2D
2I
(
D)
-
(1
2R
)
D
-
1
I
(
D
2R
)
2D
I
(
)
D
(1
2R
I
D
2R
I
P
ON
-
DS
2
OUT
ON
-
DS
2
OUT
ON
-
DS
2
OUT
ON
-
DS
2
OUT
ON
-
DS
2
OUT
ON
-
DS
2
OUT
ON
-
DS
2
IN
ON
DS
2
AVE
-
OFF
ON
DS
2
AVE
-
ON
R
ON
DS
×
×
=
×
+
×
=
×
×
+
×
×
=
×
×
+
×
×
=
−
×
×
+
×
×
≅
−
−
−
..........(7)
ESR
+
AVE
OFF
AVE
OFF
ON
DS
IN
OUT
AVE
OFF
C
I
I
2R
V
V
V
−
−
−
−
−
×
×
+
−
=
………………..(12)
D)
-
D(1
1
ESR
I
D
-
1
1
ESR
I
D
1
ESR
I
D)
(1
ESR
)
D
1
I
(
D
ESR
)
2D
I
(
D)
(1
ESR
I
D
ESR
I
P
2
OUT
2
OUT
2
OUT
2
OUT
2
IN
2
AVE
OFF
2
AVE
ON
ESR
×
×
=
×
×
+
×
×
=
−
×
×
−
+
×
×
=
−
×
×
+
×
×
≅
−
−
With a duty-cycle of 0.5, the power loss of RDS-ON
is
8R
I
R
0.5)
0.5(1
2
I
P
ON
DS
2
OUT
ON
-
DS
2
OUT
R
ON
DS
−
×
=
×
−
×
≅
−
4ESR
I
0.5)
0.5(1
1
ESR
I
P
2
OUT
2
OUT
ESR
×
=
−
×
×
≅
In fact, whether the current is the on-state or the
off-
state, it decays exponentially rather than flows
steadily, and as the root mean square value of
exponential decay is not equal to that of steady
flow, then we must use an approximation.
Let’s use another approach to look at the charge
pump circuit and
focus on the flying capacitor
C1. Referring to Fig. 20, when the circuit is in the
on state, the voltage across C1 is:
(t)
I
ESR
-
(t)
I
2R
V
(t)
V
ON
ON
ON
DS
IN
ON
-
C
×
×
−
=
−
…(9)
The average of VC1 during the on-state is:
AVE
ON
AVE
ON
ON
DS
IN
AVE
ON
C
I
ESR
I
2R
V
V
−
−
−
−
−
×
−
×
−
=
……………………….(10)
Similarly, referring to Fig. 21, when the circuit is
in
the off-state, the voltage of C1 is:
(t)
I
ESR
(t)
I
2R
V
V
(t)
V
OFF
OFF
ON
-
DS
IN
OUT
OFF
-
C
×
+
×
+
−
=
……………………………(11)
The average of VC1 during the off-state is:
The difference in charge stored in C1 between the
on-
state and off-state is the net charge transferred to
the output in one cycle.



Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13


Datasheet Download

Go To PDF Page


Link URL



Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Link to Datasheet    |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com