Electronic Components Datasheet Search
  English  ▼

X  

Preview PDF HTML

RT9241CS Datasheet(PDF) 10 Page - List of Unclassifed Manufacturers

Part # RT9241CS
Description  Two-Phase DC/DC Controller for CPU Core Power Supply
PDF  13 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  ETC [List of Unclassifed Manufacturers]
Direct Link  
Logo ETC - List of Unclassifed Manufacturers

RT9241CS Datasheet(HTML) 10 Page - List of Unclassifed Manufacturers

Back Button RT9241CS Datasheet HTML 5Page - List of Unclassifed Manufacturers RT9241CS Datasheet HTML 6Page - List of Unclassifed Manufacturers RT9241CS Datasheet HTML 7Page - List of Unclassifed Manufacturers RT9241CS Datasheet HTML 8Page - List of Unclassifed Manufacturers RT9241CS Datasheet HTML 9Page - List of Unclassifed Manufacturers RT9241CS Datasheet HTML 10Page - List of Unclassifed Manufacturers RT9241CS Datasheet HTML 11Page - List of Unclassifed Manufacturers RT9241CS Datasheet HTML 12Page - List of Unclassifed Manufacturers RT9241CS Datasheet HTML 13Page - List of Unclassifed Manufacturers  
Zoom Inzoom in Zoom Outzoom out
 10 / 13 page
background image
RT9241
Preliminary
www.richtek-ic.com.tw
DS9241-00 November 2001
10
S
5
V
V
V
T
IN
O
IN
OFF
µ
×
−
=
The sensing circuit gets IX =
by local feedback.
RSP = RSN to cancel the voltage drop caused by GM
amplifier input bias current. IX is sampled and held
just before low side MOSFET turns off (See Fig.2).
Therefore,
,
,
, for operating frequency = 200kHz
Fig. 2 Inductor Current and PWM Signal
Droop Tuning
The S/H current signals from power channels are
injected to ADJ pin to create droop voltage.
The DAC output voltage decreases by VADJ to form
the VCORE load droop(see Fig.3).
Fig. 3 Droop Tune Circuit
Protection and SS function
For OVP, the RT9241 detects the VCORE by VSEN
pin. Eliminate the parasitic delay and noise influence
on the PCB path for fast and accurate detection. The
trip point of OVP is 120% of normal output level. The
PWM outputs are pulled low to turn on the low side
MOSFET and turn off the high side MOSFET of the
synchronous rectifier at OVP. The OVP latch can
only be reset by VDD or DVD restart power on reset
sequence. The PGOOD detection trip point of VCORE
is
±8% out of the normal level. The PGOOD open
drain output pulls low when VOCRE exceeds the
range.
Soft start circuit generates a ramp voltage by
charging external capacitor with 10uA current after IC
POR acts. The PWM pulse width and VCORE are
clamped by the rising ramp to reduce the in-rush
current and protect the power devices.
Over current protection trip point is set by the resistor
RIMAX connected to IMAX pin. OCP is triggered if one
channel S/H current signal IX>
. Controller
forces PWM output latched at high impedance to turn
off both high and low side MOSFET in the power
stage and initial the hiccup mode protection. The SS
pin voltage is pulled low with a 10
µA current after it is
less than 90% VDD. The converter restarts after SS
pin voltage < 0.2V. Three times of OCP disable the
converter and only release the latch by POR acts
(see Fig.4).
Fig. 4
SP
S
L
R
R
I
×
SP
S
)
H
/
S
(
L
)
H
/
S
(
X
R
R
I
I
×
=
2
T
L
V
I
I
OFF
O
)
AVG
(
L
)
H
/
S
(
L
×
−
=
SP
S
IN
O
IN
O
)
AVG
(
L
)
H
/
S
(
X
R
R
L
2
S
5
V
V
V
V
I
I
×
µ
×
−
−
−
=
∑
×
=
X
ADJ
ADJ
I
3
2
R
V
IMAX
R
6
.
0
2
3
×
_
EA
∑
∑ I
X
FB
COMP
VDAC - VADJ
+
_
VDAC
VADJ
ADJ
RADJ
2/3 IX1
2/3 IX2
2/3 IX3
2/3 IX4
0A
0V
2V
4V
T0T1
T2
T3T4
TIME
COUNT = 1 COUNT = 2 COUNT = 3
OVERLOAD
APPLIED
SS
VCORE
IL
Falling Slope = V
O /L
I
L
I
L (S/H)
I
L (AVG)
PWM Signal & High Side MOSFET Gate Signal
Low Side MOSFET Gate Signal
Inductor Current



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