U.S. patent application number 15/186833 was filed with the patent office on 2017-08-10 for power supply apparatus.
The applicant listed for this patent is LITE-ON TECHNOLOGY CORP.. Invention is credited to MING-TSUNG HSIEH, YU-KANG LO, TE-HONG YANG.
Application Number | 20170229954 15/186833 |
Document ID | / |
Family ID | 59411409 |
Filed Date | 2017-08-10 |
United States Patent
Application |
20170229954 |
Kind Code |
A1 |
YANG; TE-HONG ; et
al. |
August 10, 2017 |
POWER SUPPLY APPARATUS
Abstract
A power supply apparatus includes a switch, a converting module
and a control module. When the switch operates in an ON state, an
input voltage is outputted through the switch to serve as an output
voltage. The converting module selectively converts the input
voltage into the output voltage. When the power supply apparatus
operates in a mode where the switch operates in an OFF state, where
the converting module performs the conversion, and where the output
voltage is stabilized at a target voltage value, and when a
condition associated with the input voltage is met, the control
module causes the output voltage to gradually change toward the
input voltage.
Inventors: |
YANG; TE-HONG; (TAIPEI,
TW) ; HSIEH; MING-TSUNG; (TAIPEI, TW) ; LO;
YU-KANG; (TAIPEI, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LITE-ON TECHNOLOGY CORP. |
TAIPEI |
|
TW |
|
|
Family ID: |
59411409 |
Appl. No.: |
15/186833 |
Filed: |
June 20, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02M 2001/0022 20130101;
H02M 1/08 20130101; H02M 3/158 20130101; H02M 3/04 20130101 |
International
Class: |
H02M 3/04 20060101
H02M003/04; H02M 1/08 20060101 H02M001/08 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 5, 2016 |
CN |
201610081811.8 |
Claims
1. A power supply apparatus comprising: an input terminal at which
an input voltage is received; an output terminal at which an output
voltage is outputted; a first switch coupled between said input and
output terminals, and operable between an ON state and an OFF state
based on a first control signal, wherein when said first switch
operates in the ON state, the input voltage is outputted through
said first switch to serve as the output voltage; a converting
module coupled between said input and output terminals, and
selectively converting the input voltage into the output voltage
based on a second control signal; and a control module coupled to
said input and output terminals, said first switch and said
converting module, and generating the first and second control
signals based at least on the input and output voltages; said power
supply apparatus being operable in at least a first mode, where the
first control signal is such that said first switch operates in the
ON state, and where the second control signal is such that said
converting module does not perform the conversion, and a second
mode, where the first control signal is such that said first switch
operates in the OFF state, and where the second control signal is
generated based on the output voltage in such a way that said
converting module performs the conversion and that the output
voltage is stabilized at a predetermined target voltage value; when
said power supply apparatus operates in the second mode and a first
condition associated with the input voltage is met, said control
module generating the first control signal in such a way that said
first switch operates in the OFF state, and generating the second
control signal in such a way that said converting module performs
the conversion and that the output voltage gradually changes toward
the input voltage.
2. The power supply apparatus of claim 1, the input voltage being
within a range of between a minimum input voltage value and a
maximum input voltage value, wherein the conversion performed by
said converting module is boost conversion, the target voltage
value is greater than the minimum input voltage value, and the
first condition is met when the input voltage is greater than a
predetermined reference voltage value, which is greater than the
minimum input voltage value and less than the maximum input voltage
value and the target voltage value.
3. The power supply apparatus of claim 2, wherein the first
condition is met when that the input voltage has been greater than
the reference voltage value for a predetermined delay time.
4. The power supply apparatus of claim 2, wherein when said power
supply apparatus operates in the second mode and the first
condition is met, the second control signal is such that the output
voltage gradually decreases so as to approach the input
voltage.
5. The power supply apparatus of claim 2, wherein said converting
module includes an inductor, a diode and a second switch that are
coupled to each other in a Y shape among said input and output
terminals and a reference node, said inductor being coupled to said
input terminal, said diode having a cathode coupled to said output
terminal, said second switch being coupled to the reference node
and further to said control module, and being operable between an
ON state and an OFF state based on the second control signal.
6. The power supply apparatus of claim 1, the input voltage being
within a range of between a minimum input voltage value and a
maximum input voltage value, wherein the conversion performed by
said converting module is buck conversion, the target voltage value
is less than the maximum input voltage value, and the first
condition is met when the input voltage is less than a
predetermined reference voltage value, which is greater than the
minimum input voltage value and the target voltage value and less
than the maximum input voltage value.
7. The power supply apparatus of claim 6, wherein the first
condition is met when the input voltage has been less than the
reference voltage value for a predetermined delay time.
8. The power supply apparatus of claim 6, wherein when said power
supply apparatus operates in the second mode and the first
condition is met, the second control signal is such that the output
voltage gradually increases so as to approach the input
voltage.
9. The power supply apparatus of claim 6, wherein said converting
module includes a second switch, an inductor and a diode that are
coupled to each other in a Y shape among said input and output
terminals and a reference node, said second switch being coupled to
said input terminal and further to said control module, and being
operable between an ON state and an OFF state based on the second
control signal, said inductor being coupled to said output
terminal, said diode having an anode coupled to the reference
node.
10. The power supply apparatus of claim 1, wherein when a
difference between the input and output voltages decreases to a
predetermined gap voltage value, said control module generates the
first and second control signals in such a way that said power
supply apparatus enters the first mode.
11. The power supply apparatus of claim 10, wherein the gap voltage
value is sufficient that the difference between the input and
output voltages is zero upon the entrance of said power supply
apparatus into the first mode.
12. The power supply apparatus of claim 1, wherein when said power
supply apparatus operates in the second mode and the first
condition is met, the second control signal is generated based on
the output voltage.
13. The power supply apparatus of claim 1, wherein an input current
is received at said input terminal, and when said power supply
apparatus operates in the second mode and the first condition is
met, the second control signal is generated based on the input
current.
14. The power supply apparatus of claim 1, wherein: when said power
supply apparatus operates in the first mode and a second condition
associated with the input voltage is met, said control module
generates the first control signal in such a way that said first
switch operates in the OFF state, and generates the second control
signal in such a way that said converting module performs the
conversion and that the output voltage gradually changes toward the
target voltage value; and when the output voltage reaches the
target voltage value, said control module generates the first and
second control signals in such a way that said power supply
apparatus enters the second mode.
15. The power supply apparatus of claim 14, the input voltage being
within a range of between a minimum input voltage value and a
maximum input voltage value, wherein the conversion performed by
said converting module is boost conversion, the target voltage
value is greater than the minimum input voltage value, and the
second condition is met when the input voltage is less than a
predetermined reference voltage value, which is greater than the
minimum input voltage value and less than the maximum input voltage
value and the target voltage value.
16. The power supply apparatus of claim 15, wherein when said power
supply apparatus operates in the first mode and the second
condition is met, the second control signal is generated in such a
way that the output voltage gradually increases from a
predetermined minimum voltage value, which is greater than or equal
to the reference voltage value and less than the target voltage
value, so as to approach the target voltage value.
17. The power supply apparatus of claim 14, the input voltage being
within a range of between a minimum input voltage value and a
maximum input voltage value, wherein the conversion performed by
said converting module is buck conversion, the target voltage value
is less than the maximum input voltage value, and the second
condition is met when the input voltage is greater than a
predetermined reference voltage value, which is less than the
maximum input voltage value and greater than the minimum input
voltage value and the target voltage value.
18. The power supply apparatus of claim 17, wherein when said power
supply apparatus operates in the first mode and the second
condition is met, the second control signal is generated in such a
way that the output voltage gradually decreases from a
predetermined maximum voltage value, which is less than or equal to
the reference voltage value and greater than the target voltage
value, so as to approach the target voltage value.
19. The power supply apparatus of claim 14, wherein when said power
supply apparatus operates in the first mode and the second
condition is met, the second control signal is generated based on
the output voltage.
20. The power supply apparatus of claim 14, wherein an input
current is received at said input terminal, and when said power
supply apparatus operates in the first mode and the second
condition is met, the second control signal is generated based on
the input current.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority of Chinese Patent
Application No. 201610081811.8, filed on Feb. 5, 2016.
FIELD
[0002] The disclosure relates to power supply, and more
particularly to a power supply apparatus operable in multiple
modes.
BACKGROUND
[0003] A conventional power supply apparatus receives a DC (direct
current) input voltage, and outputs a DC output voltage associated
with the input voltage. When the input voltage is greater than a
predetermined reference voltage value, the conventional power
supply apparatus operates in a first mode to output the input
voltage as the output voltage. When the input voltage is less than
the reference voltage value, the conventional power supply
apparatus operates in a second mode to boost-convert the input
voltage into the output voltage and stabilize the output voltage at
a predetermined target voltage value. The conventional power supply
apparatus directly switches from one of the first and second modes
to the other of the first and second modes, and thus endures
relatively high current stress. In addition, the conventional power
supply apparatus causes each of the input and output voltages to
have a relatively large ripple component, and as a result, a system
using the conventional power supply apparatus has a relatively
short lifetime and relatively poor stability.
SUMMARY
[0004] Therefore, an object of the disclosure is to provide a power
supply apparatus that can alleviate at least one of the drawbacks
of the prior art.
[0005] According to the disclosure, the power supply apparatus
includes an input terminal, an output terminal, a switch, a
converting module and a control module. An input voltage is
received at the input terminal. An output voltage is outputted at
the output terminal. The switch is coupled between the input and
output terminals, and is operable between an ON state and an OFF
state based on a first control signal. When the switch operates in
the ON state, the input voltage is outputted through the switch to
serve as the output voltage. The converting module is coupled
between the input and output terminals, and selectively converts
the input voltage into the output voltage based on a second control
signal. The control module is coupled to the input and output
terminals, the switch and the converting module, and generates the
first and second control signals based at least on the input and
output voltages. The power supply apparatus is operable in at least
a first mode, where the first control signal is such that the
switch operates in the ON state, and where the second control
signal is such that the converting module does not perform the
conversion, and a second mode, where the first control signal is
such that the switch operates in the OFF state, and where the
second control signal is generated based on the output voltage in
such a way that the converting module performs the conversion and
that the output voltage is stabilized at a predetermined target
voltage value. When the power supply apparatus operates in the
second mode and a condition associated with the input voltage is
met, the control module generates the first control signal in such
a way that the switch operates in the OFF state, and generates the
second control signal in such a way that the converting module
performs the conversion and that the output voltage gradually
changes toward the input voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Other features and advantages of the disclosure will become
apparent in the following detailed description of the embodiment
(s) with reference to the accompanying drawings, of which:
[0007] FIG. 1 is a circuit block diagram illustrating a first
embodiment of a power supply apparatus according to the
disclosure;
[0008] FIG. 2 is a timing diagram illustrating operation of the
first embodiment when switching from a second mode to a first
mode;
[0009] FIG. 3 is a timing diagram illustrating operation of the
first embodiment when switching from the first mode to the second
mode;
[0010] FIG. 4 is a circuit block diagram illustrating a second
embodiment of a power supply apparatus according to the
disclosure;
[0011] FIG. 5 is a timing diagram illustrating operation of the
second embodiment when switching from the second mode to the first
mode; and
[0012] FIG. 6 is a timing diagram illustrating operation of the
second embodiment when switching from the first mode to the second
mode.
DETAILED DESCRIPTION
[0013] Before the disclosure is described in greater detail, it
should be noted that where considered appropriate, reference
numerals or terminal portions of reference numerals have been
repeated among the figures to indicate corresponding or analogous
elements, which may optionally have similar characteristics.
[0014] Referring to FIGS. 1, 2 and 3, a first embodiment of a power
supply apparatus according to the disclosure includes an input
terminal 1, an output terminal 2, a first switch 3, a converting
module 4, a control module 5 and a capacitor 6, is used to receive
a DC (direct current) input voltage (Vin) and an input current
(Iin) at the input terminal 1, and outputs a DC output voltage
(Vout) at the output terminal 2. The input voltage (Vin) is within
a range of between a minimum input voltage value (Vin_min) and a
maximum input voltage value (Vin_max), i.e.,
Vin_min.ltoreq.Vin.ltoreq.Vin_max. The capacitor 6 is coupled
between the output terminal 2 and a reference node (e.g., ground),
and filters the output voltage (Vout).
[0015] The first switch 3 is coupled between the input and output
terminals 1, 2, and is operable between an ON state and an OFF
state based on a first control signal (CTRL1). When the first
switch 3 operates in the ON state, the input voltage (Vin) is
outputted through the first switch 3 to serve as the output voltage
(Vout).
[0016] The converting module 4 is coupled between the input and
output terminals 1, 2, and selectively converts the input voltage
(Vin) into the output voltage (Vout) based on a second control
signal (CTRL2). In this embodiment, the conversion performed by the
converting module 4 is boost conversion, and the converting module
4 includes an inductor 41, a diode 42 and a second switch 43 that
are coupled to each other in a Y shape among the input and output
terminals 1, 2 and the reference node. The inductor 41 is coupled
to the input terminal 1. The diode 42 has a cathode coupled to the
output terminal 2. The second switch 43 is coupled to the reference
node, and is operable between an ON state and an OFF state based on
the second control signal (CTRL2). As a result, a magnitude of the
output voltage (Vout) may be adjusted as desired by control of a
duty ratio of the second control signal (CTRL2).
[0017] The control module 5 is coupled to the input and output
terminals 1, 2 and the first and second switches 3, 43, and
generates the first and second control signals (CTRL1, CTRL2) based
on the input and output voltages (Vin, Vout) and/or on the input
current (Iin). In this embodiment, the control module 5 may be an
MCU (micro control unit) programmed to perform operations as
described hereinafter.
[0018] Under the control of the control module 5, the power supply
apparatus is operable in at least one of a first mode, where the
first control signal (CTRL1) is such that the first switch 3
operates in the ON state, and where the second control signal
(CTRL2) is such that the second switch 43 operates in the OFF state
(i.e., the converting module 4 does not perform the conversion),
and a second mode, where the first control signal (CTRL1) is such
that the first switch 3 operates in the OFF state, and where the
second control signal (CTRL2) is generated based on the output
voltage (Vout) in such a way that the second switch 43 alternates
between the ON and OFF states (i.e., the converting module 4
performs the conversion) and that the output voltage (Vout) is
stabilized at a predetermined target voltage value (Vtarget). In
this embodiment, the target voltage value (Vtarget) is greater than
the minimum input voltage value (Vin_min).
[0019] As shown in FIG. 2, when the power supply apparatus operates
in the second mode and a first condition associated with the input
voltage (Vin) is met, the control module 5 generates the first
control signal (CTRL1) in such a way that the first switch 3
operates in the OFF state, and generates the second control signal
(CTRL2) in such a way that the second switch 43 alternates between
the ON and OFF states (i.e., the converting module 4 performs the
conversion) and that the output voltage (Vout) gradually changes
(e.g., changes at a predetermined slope) toward the input voltage
(Vin).
[0020] In practice, the control module 5 may compare the output
voltage (Vout) and the input voltage (Vin) so as to adjust the duty
ratio of the second control signal (CTRL2), causing the output
voltage (Vout) to gradually change toward the input voltage (Vin).
As a result, the power supply apparatus operates neither in the
first mode nor in the second mode. In this embodiment, the first
condition is met when the input voltage (Vin) has been greater than
a predetermined reference voltage value (Vref), which is greater
than the minimum input voltage value (Vin_min) and less than the
maximum input voltage value (Vin_max) and the target voltage value
(Vtarget), for a predetermined delay time (Tdelay). Moreover, in
this embodiment, when the power supply apparatus operates in the
second mode and the first condition is met, the second control
signal (CTRL2) is generated based on one of the output voltage
(Vout) and the input current (Iin) in such a way that the output
voltage (Vout) gradually decreases (e.g., decreases at the
predetermined slope) so as to approach the input voltage (Vin). It
should be noted that, in other embodiments, the first condition may
be irrelevant to the delay time (Tdelay).
[0021] As shown in FIG. 2, when a difference between the input and
output voltages (Vin, Vout) decreases to a predetermined gap
voltage value (Vgap), the control module 5 generates the first and
second control signals (CTRL1, CTRL2) in such a way that the power
supply apparatus enters the first mode. It should be noted that
FIG. 2 depicts a circumstance where the power supply apparatus has
a zero processing time. In reality, the processing time of the
power supply apparatus would not be zero. Therefore, when the
difference between the input and output voltages (Vin, Vout)
decreases to the gap voltage value (Vgap), the power supply
apparatus does not enter the first mode right away; and when the
power supply apparatus enters the first mode, the difference
between the input and output voltages (Vin, Vout) would have
decreased to be less than the gap voltage value (Vgap). In this
embodiment, the gap voltage value (Vgap) is predetermined to be
sufficient that the difference between the input and output
voltages (Vin, Vout) is zero upon the entrance of the power supply
apparatus into the first mode.
[0022] As shown in FIG. 3, when the power supply apparatus operates
in the first mode and a second condition associated with the input
voltage (Vin) is met, the control module 5 generates the first
control signal (CTRL1) in such a way that the first switch 3
operates in the OFF state, and generates the second control signal
(CTRL2) in such away that the second switch 43 alternates between
the ON and OFF states (i.e., the converting module 4 performs the
conversion) and that the output voltage (Vout) gradually changes
(e.g., changes at a predetermined slope) toward the target voltage
value (Vtarget). In practice, the control module 5 may compare the
output voltage (Vout) and the target voltage value (Vtarget) so as
to adjust the duty ratio of the second control signal (CTRL2),
causing the output voltage (Vout) to gradually change toward the
target voltage value (Vtarget). In this embodiment, the second
condition is met when the input voltage (Vin) is less than the
reference voltage value (Vref); and when the power supply apparatus
operates in the first mode and the second condition is met, the
second control signal (CTRL2) is generated based on one of the
output voltage (Vout) and the input current (Iin) in such a way
that the output voltage (Vout) gradually increases (e.g., increases
at the predetermined slope) from a predetermined minimum voltage
value (Vmin), which is greater than or equal to the reference
voltage value (Vref) and less than the target voltage value
(Vtarget), so as to approach the target voltage value (Vtarget). It
is noted that, when the minimum voltage value (Vmin) is greater
than the reference voltage value (Vref), the output voltage (Vout)
may directly jump from the reference voltage value (Vref) to the
minimum voltage value (Vmin) within a very short time as shown in
FIG. 3 since the capacitor 6 causes the output voltage (Vout) to
change continuously.
[0023] As shown in FIG. 3, when the output voltage (Vout) reaches
the target voltage value (Vtarget), the control module 5 generates
the first and second control signals (CTRL1, CTRL2) in such a way
that the power supply apparatus enters the second mode.
[0024] In view of the above, the power supply apparatus of this
embodiment has the following advantages:
[0025] 1. With the control module 5 operating in the corresponding
specific manner as described above when the power supply apparatus
operates in the second mode and the first condition is met, the
power supply apparatus draws a relatively small inrush current and
thus endures relatively low current stress when switching from the
second mode to the first mode.
[0026] 2. With the control module 5 operating in the specific
manner as described above when the power supply apparatus operates
in the first mode and the second condition is met, the output
voltage (Vout) increases relatively slowly to the target voltage
value (Vtarget) and thus the power supply apparatus endures
relatively low current stress when the power supply apparatus
switches from the first mode to the second mode.
[0027] 3. Operation of the control module 5 when the power supply
apparatus operates in the second mode and the first condition is
met, and operation of the control module 5 when the power supply
apparatus operates in the first mode and the second condition is
met causes the power supply apparatus to continuously draw energy
at the input terminal 1, so each of the input and output voltages
(Vin, Vout) has a relatively small ripple component, and thus a
system using the power supply apparatus has a relatively long
lifetime and relatively good stability.
[0028] 4. With the delay time (Tdelay), undesired switching of the
power supply apparatus from the second mode to the first mode when
the input voltage (Vin) is not stable or contains noise can be
prevented.
[0029] Referring to FIGS. 4, 5 and 6, a second embodiment of a
power supply apparatus according to the disclosure is a
modification of the first embodiment, and differs from the first
embodiment in that:
[0030] 1. The conversion performed by the converting module 4' is
buck conversion, and the converting module 4' includes a second
switch 44, an inductor 45 and a diode 46 that are coupled to each
other in a Y shape among the input and output terminals 1, 2 and
the reference node. The second switch 44 is coupled to the input
terminal 1 and further to the control module 5', and is operable
between an ON state and an OFF state based on the second control
signal (CTRL2). The inductor 45 is coupled to the output terminal
2. The diode 46 has an anode coupled to the reference node.
[0031] 2. The target voltage value (Vtarget) is less than the
maximum input voltage value (Vin_max).
[0032] 3. The first condition is met when the input voltage (Vin)
has been less than the reference voltage value (Vref), which is
greater than the minimum input voltage value (Vin_min) and the
target voltage value (Vtarget) and less than the maximum input
voltage value (Vin_max), for the predetermined delay time (Tdelay).
It should be noted that, in other embodiments, the first condition
may be irrelevant to the delay time (Tdelay).
[0033] 4. When the power supply apparatus operates in the second
mode and the first condition is met, the second control signal
(CTRL2) is generated based on one of the output voltage (Vout) and
the input current (Iin) in such a way that the output voltage
(Vout) gradually increases (e.g., increases at a predetermined
slope) so as to approach the input voltage (Vin).
[0034] 5. The second condition is met when the input voltage (Vin)
is greater than the reference voltage value (Vref).
[0035] 6. When the power supply apparatus operates in the first
mode and the second condition is met, the second control signal
(CTRL2) is generated based on one of the output voltage (Vout) and
the input current (Iin) in such a way that the output voltage
(Vout) gradually decreases (e.g., decreases at a predetermined
slope) from a predetermined maximum voltage value (Vmax), which is
less than or equal to the reference voltage value (Vref) and
greater than the target voltage value (Vtarget), so as to approach
the target voltage value (Vtarget). It is noted that, when the
maximum voltage value (Vmax) is smaller than the reference voltage
value (Vref), the output voltage (Vout) may directly jump from the
reference voltage value (Vref) to the maximum voltage value (Vmax)
within a very short time as shown in FIG. 6 since the capacitor 6
causes the output voltage (Vout) to change continuously.
[0036] In view of the above, the power supply apparatus of this
embodiment has the following advantages:
[0037] 1. With the control module 5' operating in the prescribed
manner when the power supply apparatus operates in the second mode
and the first condition is met, the power supply apparatus draws a
relatively small inrush current and thus endures relatively low
current stress when switching from the second mode to the first
mode.
[0038] 2. With the control module 5' operating in the manner
described above when the power supply apparatus operates in the
first mode and the second condition is met, the output voltage
(Vout) decreases relatively slowly to the target voltage value
(Vtarget) and thus the power supply apparatus endures relatively
low current stress when the power supply apparatus switches from
the first mode to the second mode.
[0039] 3. Operation of the control module 5' when the power supply
apparatus operates in the second mode and the first condition is
met, and operation of the control module 5' when the power supply
apparatus operates in the first mode and the second condition is
met causes the power supply apparatus to continuously draw energy
at the input terminal 1, so each of the input and output voltages
(Vin, Vout) has a relatively small ripple component, and thus a
system using the power supply apparatus has a relatively long
lifetime and relatively good stability.
[0040] 4. With the delay time (Tdelay), undesired switching of the
power supply apparatus from the second mode to the first mode when
the input voltage (Vin) is not stable or contains noise can be
prevented.
[0041] In the description above, for the purposes of explanation,
numerous specific details have been set forth in order to provide a
thorough understanding of the embodiment (s). It will be apparent,
however, to one skilled in the art, that one or more other
embodiments may be practiced without some of these specific
details.
[0042] It should also be appreciated that reference throughout this
specification to "one embodiment," "an embodiment," an embodiment
with an indication of an ordinal number and so forth means that a
particular feature, structure, or characteristic may be included in
the practice of the disclosure. It should be further appreciated
that in the description, various features are sometimes grouped
together in a single embodiment, figure, or description thereof for
the purpose of streamlining the disclosure and aiding in the
understanding of various inventive aspects.
[0043] While the disclosure has been described in connection with
what is (are) considered the exemplary embodiment(s), it is
understood that the disclosure is not limited to the disclosed
embodiment(s) but is intended to cover various arrangements
included within the spirit and scope of the broadest interpretation
so as to encompass all such modifications and equivalent
arrangements.
* * * * *