USO0RE43 946E
(19)
United States
(12) Reissued Patent
(10) Patent Number:
Sase et a]. (54)
US RE43,946 E
(45) Date of Reissued Patent:
DIGITAL CONTROL SWITCHING INFORMATION PROCESSING EQUIPMENT
2005/0127881 A1
6/2005 Sase et a1.
2006/0055388 A1
3/2006 T t 1. ang e a
Jan. 29, 2013
FOREIGN PATENT DOCUMENTS
(75)
Inventors: Takashi Sase, Hitachi (JP); Yosuke Kawakubo, OdaWara (JP)
JP JP
02426209 04-26362
1/1992 1/1992
JP
04-266108
9/1992
(73) Asslgnee. HItachI, Ltd., Tokyo (JP)
JP
JP
2003061351
2000-232346
200%
JP
2003-125583
4/2003
(21)
JP
2005-45983
2/2005
JP
2005184870
7/2005
'
(22)
.
-
-
APP1- NO-I 13/399,572 Filed:
Feb. 17, 2012
8/2000
W0
WO 2005/053143
6/2005
W0
WO 2006/037214
4/2006
Related US. Patent Documents R .
f
OTHER PUBLICATIONS
e1ssue o :
(64)
Patent No;
7,990,122
Of?ce Action in JP2007-201087, issued Jan. 17, 2012 (2 pgs, in
Issued:
Aug. 2, 2011
JaPane$e)~_
Appl' No‘:
11/853,916
Of?ce Action In JP2007-201087, Issued Aug. 23, 2011 (2 pgs, In
Filed:
Sep. 12, 2007
Japanese)‘
_
(30)
_
_
_
_
_
_
Primary Examiner * Harry Behm
Forelgn Apphcatlon Prmnty Data
(74) Attorney, Agent, or Firm *Antonelli, Terry, Stout &
001. 2, 2006
(JP) ............................... .. 2006-271082
Kraus’ LLP'
Aug. 1, 2007
(JP) ............................... .. 2007-201087
(57)
(51) Int_ C]_
ABSTRACT
[To provide a] A digital control switching poWer-supply
G051? 1/575 (52)
_
(200601)
device is provided which is capable of suitably achieving fast
us. Cl. ...................................... .. 323/283; 323/284
transient response at the time Of a Sudden load Change- In
(58) Field of Classi?cation Search 323/283 323 223 272’ See application ?le for Complete gearch hist’ory ’
parallel With normal digital signal processing means that outputs a PWM pulse signal having a desired duty, transient variation detection means composed of a CR ?lter provided
'
(56)
across an output inductor and a Window comparator is pro
References Cited
vided in preparation for a sudden load change. If a sudden decrease in load is detected, a PWM pulse signal having a duty of 0% is forcedly output, and if a sudden increase in load is detected, a PWM pulse signal having a duty of 100% is forcedly 011119111
U.S. PATENT DOCUMENTS 5,594,631 A
6,546,048 B1 6,965,502 B2 2003/0231010 A1
1/1997 Katooziet a1.
4/2003 Ichiba e161. 11/2005 Duffyetal. 12/2003 Sase et a1.
23 Claims, 17 Drawing Sheets
Vi Ts
‘
Q1
L
“0%
ton 1
-
-
'06:
~1Q2
CP1
Vref+A
an
\B°
I I" -
VoCR
CPZ }___ __A/_"‘_1°°—z Wei-A TVD 0/100
o _
"
L/
-
0%
DPWM
I5
/ % /”
/DVC
VrefiA
DIGITAL CONTROL
PWM Deo
|
/\/ VOLTAGE
5
¢
(PID)
I
4
DRIVER GATE _| DRV
m
V0 -
VA
n/
MDref :
D°
A/D
"H": 100% DIGITAL SIGNAL PROCESSING (STEADY CONTROL SECTION)
VFB
4’ ,\ AD 0
°
US. Patent
Jan. 29, 2013
Sheet 1 0f 17
US RE43,946 E
FIG. 1
,. ,,
‘II‘IL/ L :DoPo/\?IM /\;IGITAL o M //
51 T
VrefiA/
CONTROL
¢ / % {WM Deo /” "H": 100%
(PID)
n/VA
Dref
D0
VFB
A A/D\ 1/ ‘—/\J\
SEL DIGITAL SIGNAL PROCESSING (STEADY CONTROL SECTION)
ADO
FIG. 2 COMPARISON LEVEL
(1/0 01100
Vref + A
PWM Duty (SUDDEN DECREASE)
Vout Vref — A
I
H
L
H
H
DESIRED u (STEADY) 100%
(SUDDEN INCREASE)
US. Patent
Jan. 29, 2013
Sheet 2 0f 17
US RE43,946 E
FIG. 3 (a) TRANSIENT CONTROL + DIGITAL CONTROL
Vout (b) DIGITAL CONTROL ONLY
1 |
I I l
I
"L":0%
D:
E
,7- 8 d,
/ :
/“
m
DPWM
"’ \"H":100%
Do
VOLTAGE
Dec,
(P'D)
Mm“ 1
DIGITAL SIGNAL PROCESSING (STEADY CONTROL SECTION)
FIG. 5
VOUt“
‘i
ADD
CONTROL
SEL
I I
5\ ________________ /, 'A/D‘ in "1
DIGITAL
W PWM
;
I %D
Vref'I'A
Vref I
LOAD CURRENT Io
US. Patent
Jan. 29, 2013
Sheet 3 0f 17
US RE43,946 E
FIG. 6 VoCR = Vref' = Vref + ESR -lo Vout = Vref Vref -
LOAD CURRENT lo
FIG. 7 Q1
Ts
L
w
:iETon
‘
,
A,
_ GAITE DRIVER
4
-
mg
I _
.
but’!Q2
R2
I
V0
.
Q2
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R"
DRV
|_ I
Il M100
,4
M DVC
v L/uLn; 0% I
SEL
SELCTOR
DPWM
ADDA+ +7 DAA+
VA‘' ———\q ADD It
DIGITAL VOLTAGE
I ADD
D/A}
J'-—\ DO +
4
‘
DIGITAL SIGNAL PROCESSING (STEADY CONTROL SECTION)
DOCR ADO
I/VFB
US. Patent
Jan. 29, 2013
Vi
Ts
Sheet 5 0f 17
Q1
L
M
El T-
‘
‘
GATE
_|
R2
// DRIVER
DRV
a0
0P1
V0
‘
'
L’pw-i kzl
Ton
,
"06/
US RE43,946 E
0
Q2
0 2
RL
I o
/
’
+
,,/Vref'+A
0P2 j 1
l/moo >\/;!—i/Vref-A
VuCR
TVD ——
D
I 00
i ,4
"/1
f’
VOLTAGE
CONTROL
/"
SEL
"H": 100%
—“ +w
_
.
__
-1
DAADAA+
I ,/DA I
[la/A};
. . _ _ . _ . -
\
_ _ _ - J
(PID)
I"
+
SUBo
— 1/ J""\
DOCR
ND
‘
IdDref'
DIGITAL SIGNAL PROCESSING (STEADY CONTROL SECTION)
Do ADoCR
‘,+
r-——1_+ ADD <
/L——-|
ADo
I‘,
Dref
ADDref
FIG. 11 + Dref (or Dref')
ADD23
.
,
‘L. ADD
L.
DIGITAL
B
De"
_
I
5
¢ / % \PWM
_
sue H WA}.
SUBA ABBA
VA: ,xDVC
"L": 0% y 74/ S DPWM
_
r ---------- - -
Do (or DOOR)
A/0
MVFB
US. Patent
Jan. 29, 2013
FIG. 15
Sheet 7 0f 17
US RE43,946 E
PWM
REG 1
COUNT
//
g
‘z0
I35
8
%0
58II
Dec
\~ 5 L» 22 A 22 +44 O
O
086 \\
+ OsO DPWM
FIG. 16
PWM DCP
COUNT
f; z
$—>COUNTER OMPARTOO ‘u r"
, REG
LATCH REGISTR 5 O 7:
I
O o o P: r
FIG. 17 010
Q5
3-
01100 OSM
DA
/ I;PWMI‘/VI
OSM
V/I
80 DeO
D/A<-4/
US. Patent
Jan. 29, 2013
US RE43,946 E
Sheet 11 0f 17
FIG. 22 Ts
La Col
I
IM
DRV/J
GATE DRIVER
02
O2
RL I
PhaseI
VoCR
mm
MCYI002® CP 100
,ovc
pf 4w
"L": 0% Dec
l-
/(SELCTOR
4/ EDPWM Z
i086 :PSFT
+
DMV
gMEMORIZE
\SELCTOR
J
su
/
B +
MAXIMUM VA .UE
SUB SEL2 ,.
ADoCR
+ my
SUB CLK SUBME-ET‘T
"’
ADDref
ADD
(PID)
PWM
(I) m L "H": 100%
ADDM Vref-
DIGITAL VOLTAGE CONTROL
w
H": 100% DPWMZ
DIGITAL VOLTAGE CONTROL
PWM2 Deo2 "L": 0%
(PID)
AD 00 R2
TRAN SIENT
mm
w
AM'T {104 L2 Phase2
DRVZ /
US. Patent
Jan. 29, 2013
Sheet 12 0f 17
US RE43,946 E
FIG. 23 Vi
Q1
‘
'06 L
I
151%
V0
1
DAA+ I
1/
In: g
"L": 0% D
,7- 8
PWM
DVG
l <
: DIGITAL
I‘, Do
VOLTAGE
ADO
-|
d: /“ / 5,4 ‘\PWM Deo wag“ "H": 100%
2
SE"
‘
DIGITAL SIGNAL
‘D/A} VFB m M LT
L ------------------ ---J
PRO0ESSING(STEADY CONTROL SECTION)
w’ m“
US. Patent
Jan. 29, 2013
Sheet 14 0f 17
US RE43,946 E
FIG. 25
00 ¢ ,/
I Q2
//
M VA
g
Q [5
+A Vref_.
‘31>’
"L":
,,/DPWM
DIGITAL
Dref
VOLTAGE
DPWM CONTROL PWM Deo (P10) DIGITAL SIGNAL PROCESSING
Do VFB A/D \ "/ "' ;~'\ ADO
(STEADY CONTROL SECTION)
FIG. 26 Dref
Voref=(1+(Rf+ RfA)/(Ri+RiA )) Vref RE A =RfA
RL ,
US RE43,946 E 1
2
DIGITAL CONTROL SWITCHING POWER-SUPPLY DEVICE AND
obtained by digitizing a fed-back output voltage of the switching power-supply device and a digital reference volt age signal obtained by digitizing a reference voltage of a
INFORMATION PROCESSING EQUIPMENT
command signal is zero and a digital pulse width modulation (DPWM) generator that generates a pulse width modulation
Matter enclosed in heavy brackets [ ] appears in the original patent but forms no part of this reissue speci?ca
(PWM) pulse signal; a pair of power semiconductor switch ing components driven by the PWM pulse signal; an LC
tion; matter printed in italics indicates the additions made by reissue.
smoothing ?lter that converts a square wave voltage resulting
from switching of said pair of power semiconductor switch ing components into a direct current; transient variation detection means that detects a transient variation at the time of a sudden load change; and selection means that selects any of
BACKGROUND OF THE INVENTION
a PWM pulse signal having a desired duty generated by said
1. Field of the Invention The present invention relates to a digital control switching power-supply device for setting an output voltage at a refer ence voltage of a command signal and information process
DPWM generator and a PWM pulse signal having a preset ?xed duty according to the result of detection by said transient variation detection means, and said pair of power semicon
ductor switching components is driven by the PWM pulse
ing equipment provided with the digital control switching power-supply device.
signal selected by said selection means.
2. Background Art As disclosed in the JP Patent Publication (Kokai) No. 2003-61351, when a conventional digital control switching power-supply device detects a sudden load change, it copes with the sudden load change by generating a sudden load
20
change PWM pulse signal by switching a control gain of digital voltage control means, which corresponds to an analog
25
control error ampli?er.
In addition, the transient variation detection means has a CR ?lter for transient variation detection provided across an inductor L of said LC smoothing ?lter and a transient varia 30
tor switching components is driven under the control of digi tal voltage control means and a DPWM generator, which
carry out digital signal processing. Since the digital signal processing is a sampling control system, the digital signal processing has a disadvantage that the processing speed is
PWM pulse having a desired duty generated by the DPWM generator in said digital signal processing section in other cases.
SUMMARY OF THE INVENTION
According to the method described in the JP Patent Publi cation (Kokai) No. 2003-61351, a pair of power semiconduc
In addition, said selection means selects a PWM pulse signal having a duty of 100% in a case where said transient variation detection means detects a sudden increases in load, selects a PWM pulse signal having a duty of 0% in a case where a sudden decrease in load is detected, and selects a
35
tion detection circuit composed of a window comparator provided at an output terminal of the CR ?lter, said transient variation detection circuit compares an output voltage of said CR ?lter with upper and lower limit values preset around a reference voltage set to provide a desired output voltage of the
digital control switching power-supply device in order to obtain detection information at the time of a sudden load
limited, and thus a signi?cant output voltage variation occurs
change and supplies the comparison result to said selection
in response to a sudden load change that leads to a current
means, and said selection means receives said comparison result as a selection signal and selects from among said PWM
change (di/dt) of several hundred A/us or greater, and sul? ciently fast transient response cannot be achieved. In addition, in order to suppress the output voltage varia tion, a capacitor of an LC smoothing ?lter has to have a larger capacitance, and manufacturing a compact system or device at low cost becomes dif?cult because the number of external
40
components increases.
45
The present invention has been made in view of such cir cumstances, and an object of the present invention is to pro vide a digital control switching power-supply device that uses a digital signal processing to generate a PWM pulse for set ting the output voltage at a reference voltage of a command signal, in which fast transient response can be achieved while suppressing an output voltage variation at the time of a sud
den load change even if the speed of the digital signal pro cessing used is low. In order to attain the object described above, according to
pulse signals based on said comparison result.
Furthermore, the digital control switching power-supply device according to the present invention can be con?gured to
perform a multi-phase operation. Speci?cally, a power-sup ply device according to the present invention is a digital control switching power-supply device having a plural num ber of power supply units, in which each power supply unit
comprises: a digital signal processing section having digital voltage control means that performs control so that the dif 50
ference signal between a digital output voltage signal obtained by digitizing a fed-back output voltage of the switching power-supply device and a digital reference volt age signal obtained by digitizing a reference voltage of a command signal is zero and a digital pulse width modulation (DPWM) generator that generates a pulse width modulation
55
the present invention, transient variation detection means is
(PWM) pulse signal; a pair of power semiconductor switch ing components driven by the PWM pulse signal; an LC
provided in preparation for a sudden load change, in addition
smoothing ?lter that converts a square wave voltage resulting
to normal digital signal processing means, such as means for performing feed back control of a voltage signal. If a sudden load change occurs, the output voltage control can be per
from switching of said pair of power semiconductor switch ing components into a direct current; transient variation 60
formed without performing the digital signal processing, so
detection means that detects a transient variation at the time of a sudden load change; and selection means that selects any of
that fast transient response can be achieved while suppressing
a PWM pulse signal having a desired duty generated by said
an output voltage variation. Speci?cally, a digital control
DPWM generator and a PWM pulse signal having a preset ?xed duty according to the result of detection by said transient variation detection means, said pair of power semiconductor
switching power-supply device according to the present invention comprises: a digital signal processing section hav
65
ing digital voltage control means that performs control so that
switching components is driven by the PWM pulse signal
the difference signal between a digital output voltage signal
selected by said selection means, and a common output
US RE43,946 E 4
3 capacitor is shared by said LC smoothing ?lters of said plural number of poWer supply units. The digital control switching poWer-supply device accord
FIG. 17 is a circuit block diagram shoWing an example in
Which the digital PWM generator and the selector according to the fourth embodiment is implemented by one circuit (a
one-shot multivibrator);
ing to the present invention can be applied to information processing equipment, such as a HDD. Furthermore, the
FIG. 18 is a circuit diagram shoWing details of the one-shot multivibrator used in the example shoWn in FIG. 17;
poWer-supply device can be implemented as an IC and incor porated in a package of a semiconductor chip such as CPU and a memory or can be incorporated in a semiconductor chip
FIG. 19 is a time chart for illustrating an operation of the one-shot multivibrator shoWn in FIG. 18; FIG. 20 is a circuit block diagram shoWing a con?guration
such as CPU and a memory.
of a digital control sWitching poWer-supply device designed
Further features of the present invention Will be apparent from the detailed description of the preferred embodiments
for a multi-phase operation according to a ?fth embodiment
of the present invention;
and the accompanying draWings.
FIG. 21 is a circuit block diagram shoWing a con?guration
According to the present invention, there can be provided a
of a digital control sWitching poWer-supply device designed
digital control sWitching poWer-supply device that can
for a multi-phase operation according to a sixth embodiment
achieve fast transient response While suppressing an output voltage variation at the time of a sudden load change even if
of the present invention;
the speed of the digital signal processing for voltage control is
?guration of a digital control sWitching poWer-supply device designed for a multi-phase operation according to the sixth embodiment of the present invention;
FIG. 22 is a circuit block diagram shoWing another con
loW. 20
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 23 is a circuit block diagram shoWing a con?guration
of a digital control sWitching poWer-supply device according FIG. 1 is a circuit block diagram shoWing a con?guration of
to a seventh embodiment of the present invention; FIG. 24 is a circuit block diagram shoWing a con?guration
a digital control sWitching poWer-supply device according to a ?rst embodiment of the present invention; FIG. 2 is a diagram shoWing an operating state transition of
25
for a multi-phase operation according to the seventh embodi ment of the present invention; FIG. 25 is a circuit block diagram shoWing a con?guration
the poWer-supply device shoWn in FIG. 1; FIG. 3 is a diagram shoWing an output response Waveform of the poWer-supply device shoWn in FIG. 1 at the time of
sudden load increase;
of a digital control sWitching poWer-supply device designed
of a digital control sWitching poWer-supply device according 30
FIG. 4 is a block diagram of the poWer-supply device
to an eighth embodiment of the present invention; FIG. 26 is a circuit block diagram shoWing a speci?c con
shoWn in FIG. 1 in Which a (VrefiA) generating circuit is
?guration of a (VrefzA) generating circuit according to the
speci?cally shoWn;
eighth embodiment;
FIG. 5 is a diagram shoWing the output voltage versus the load current of the poWer-supply device shoWn in FIG. 1;
FIG. 27 is a circuit block diagram shoWing a con?guration 35
FIG. 6 is a diagram shoWing the effect of an ESR of an
output inductor in the ?rst embodiment; FIG. 7 is a circuit block diagram shoWing a digital control sWitching poWer-supply device according to a second embodiment, in Which the (VrefiA) generating circuit shoWn in FIG. 4 is improved; FIG. 8 is a circuit block diagram shoWing a con?guration of a digital control sWitching poWer-supply device according to a third embodiment of the present invention; FIG. 9 is a diagram shoWing the effect of an ESR of an output inductor shoWn in FIG. 8; FIG. 10 is a circuit block diagram shoWing a digital control sWitching poWer-supply device according to a fourth embodi
ment of the present invention, in Which output regulation compensation shoWn in FIG. 8 is implemented;
eighth embodiment; FIG. 28 is a circuit block diagram shoWing a con?guration
of the digital control sWitching poWer-supply device accord 40
ing to the ?rst embodiment of the present invention that is
composed of a commercially available digital signal process ing section and a selector and a (VrefiA) generating circuit
externally added thereto; FIG. 29 is a circuit block diagram shoWing a con?guration 45
of a multi-phase digital control sWitching poWer-supply device formed based on the con?guration according to the
eighth embodiment of the present invention; FIG. 30 is a diagram shoWing a con?guration of a poWer supply for information processing of a HDD on Which the 50
FIG. 11 is a circuit block diagram shoWing a speci?c circuit
digital control sWitching poWer-supply device according to any of the embodiments of the present invention is mounted; and FIG. 31 is a diagram shoWing another con?guration of a poWer supply for information processing of a HDD on Which
con?guration of digital voltage control means according to the fourth embodiment; FIG. 12 is a circuit block diagram shoWing a speci?c con
?guration of a selector according to the fourth embodiment;
in Which commercially available ICs are used as transient variation detection means and a selector according to the
55
FIG. 13 is a circuit block diagram shoWing a speci?c con
the digital control sWitching poWer-supply device according to any of the embodiments of the present invention is mounted.
?guration of a digital PWM generator according to the fourth
embodiment; FIG. 14 is a circuit block diagram shoWing a modi?cation
of the digital PWM generator shoWn in FIG. 13; FIG. 15 is a circuit block diagram shoWing another speci?c con?guration of the digital PWM generator according to the fourth embodiment; FIG. 16 is a circuit block diagram shoWing an example in
60
Which a phase-locked loop circuit is used as an oscillator of
65
the digital PWM generator according to the fourth embodi ment;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A digital control sWitching poWer-supply device according to the present invention has transient variation detection means, Which is provided in parallel With a normal digital
signal processing system, and thereby alloWs fast transient response of a poWer-supply device for a buck-type DC/DC converter to a sudden load change. In addition, the digital
