PWMControlled,PWM/PFMSwitchableStep‐downDC/DCConverters
Series
577
5
■GeneralDescription ■Features
■Applications
■TypicalApplicationCircuit ■TypicalPerformance
Characteristic
The XC6376/77 series are step-down DC/DC converters with built-in P-
channel power MOSFETs. A highly efficient DC/DC converter with output
currents of 500mA can be realised using only four peripherals - a coil, a
diode and 2 capacitors.
Output voltage can be internally set-up in 0.1V increments (±2.5%)
between 1.5V and 6.0V (VOUT type). Alternatively, output voltage can be
set-up at will using a 1.0V internal reference voltage source and
peripherals (FB type). It is possible to reduce the size of the peripherals
used since the switching frequency is 300kHz.
The PWM//PFM switchable XC6377 operates in PFM mode during light
loads and is highly efficient from light loads to large output currents.
Required values for soft start time can be regulated via the external
capacitor and the stand-by function reduces supply current to less than
2.5µA.
U.V.L.O and protection are built-in.
Input voltage range : 1.8V~10V
Output voltage range : 1.5V~6.0V programmable in 0.1V steps
(±2.5%)
Oscillator frequency : 300kHz (±1.5%)
: Custom products for 180, 500kHz
Max. output current : 500mA (min.)VIN=3.6V, VOUT=3.0V
High Efficiency : 95% (typ.)
Stand-by capability : ISTB=2.5µA (max.)
Soft-start time set-up externally type
U.V.L.O, Pch boost, VOUT reset functions available
Internally set-up output voltage type (VOUT)
Externally set-up output voltage type (FB)
Pchannel Power MOSFET built-in
Package : SOP-8
●Electronic Information Organizers
●Palmtops
●Cellular and portable phones
●Portable Audio Systems
●Various Multi-function Power Supplies
◆P-Channel Power MOSFET Built-in
◆Maximum Output Current : 500mA
◆Output Voltage Range : 1.5~6.0V
◆Oscillator Frequency : 300kHz
◆Maximum Duty Ratio : 100%
◆High Efficiency : 95%
◆SOP-8 Package
0
40
20
60
80
100
0.1 1 10 100 1000
Efficiency:EFFI（%）
OutputCurrent:IOUT（mA）
XC6377A333
5.0V
VIN＝3.96V
L＝22μH（CR54）
8.0V
CL
（Tantalum）
CIN
（Tantalum）
1
2
3
4
8
7
6
5
L
VIN
CE/
VOUT
SD1
Css
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XC6376/6377
Series
578
5
START
OutputVoltageInternallyset-up(VOUT)
ResetFunction-Yes
ResetFunction-No
ProtectCircuit-Yes
ProtectCircuit-Yes
ProtectCircuit-No
ProtectCircuit-No
ProtectCircuit-Yes
ProtectCircuit-No
OutputVoltageExternallyset-up(FB)
XC6376E,XC6377E
XC6376F,XC6377F
XC6376A,XC6377A
XC6376C,XC6377C
XC6376B,XC6377B
XC6376D,XC6377D
■PinConfiguration ■PinAssignment
■ProductClassification
●Selection Guide
PIN
NUMBER
PIN
NAME FUNCTION
1
3
2
V
IN
P_BST
EXT/2
Power supply input
P-ch gate boost
External drive pin 2
("L" when Pch MOSFET ON)
4
6
5
CE
GND
V
OUT
(FB)
Chip enable
Soft-start capacitor connection
Ground
Output voltage monitor
(FB=externally set-up type)
External drive pin 1
("L" when P-ch MOSFET ON)
7
8
EXT/1
LX P-ch power MOSFET switch
1
2
3
4
8
7
6
5
SOP-8
（TOPVIEW）
VIN LX
EXT/2 EXT/1
PBST GND
CE VOUT
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XC6376/6377
Series
579
5
A
B
3
S
V
OUT
FB
C
D
SYMBOL V
OUT
/FB V
OUT
RESET FUNCTION INTEGRAL CIRCUIT PROTECTION
V
OUT
FB
E
F
V
OUT
V
OUT
NO
-
NO
-
YES
YES
YES
YES
NO
NO
YES
NO
Output voltage e.g. 3.0V output : (
②
=3,
③
=0)
FB products (B,D types) : (
②
=1,
③
=0)
Oscillator frequency 300kHz
5 Oscillator frequency 500kHz
2 Oscillator frequency 180kHz
Package SOP-8
R
L
Embossed Tape : Standard Feed
: Reverse Feed
XC6376 Series PWM Control
XC6376①②③④⑤⑥
XC6377 Series PWM/PFM switching control
(same as XC6376 series)
XC6377①②③④⑤⑥
①
②
③
④
⑤
⑥
●Ordering Information
■PackagingInformation
●SOP-8
4.2±0.4 1.5±0.1
0〜0.25
0.35〜1.0
0.4±0.1
1.27±0.03
0.2 -0.1
+0.05
5.0 -0.2
+0.5
6.1 -0.3
+0.4
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XC6376/6377
Series
580
5
■BlockDiagram
■Marking
XC6376, XC6377 Series A,C types (VOUT)
VOUT
CE
VIN
CE
Vrefwith
SoftStart, PWM/PFM
Controller
Phase
Compensation
Protection
RampWave
Generator,
OSC
Buffer,
Driver
+
-
+
-
ErrorAmp.
PWM
Comparator
P-chPOWERMOS
FET
LX
EXT/1
EXT/2
PBST
GND
XC6376, XC6377 Series B,D types (FB)
FB
CE
VIN
CE
Vrefwith
SoftStart, PWM/PFM
Controller
Phase
Compensation
Protection
RampWave
Generator,
OSC
Buffer,
Driver
+
-
+
-
ErrorAmp.
PWM
Comparator
P-chPOWERMOS
FET
LX
EXT/1
EXT/2
PBST
GND
MarkY :Yearcode
    RepresentsthesingledigitofDominicalYear
MarkAA:AssemblyLot
   Denotestheproductionlotnumber0to9,AtoZrepeated(G.I.J.O.Q.Wexcepted)
   Higherorderzeroisnotrepresented.
qwertyui
EX：XC6376A303SR
q
LOGOMARK
w
3
i
0
u
3
y
A
t
6
r
7
e
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XC6376, XC6377 Series E,F types (VOUT, VOUT rest function)
VOUT
CE
VIN
CE
Vrefwith
SoftStart PWM/PFM
Controller
Phase
Compensation
Protection
RampWave
Generator,
OSC
Buffer,
Driver
+
-
+
-
ErrorAmp.
PWM
Comparator
P-chPOWERMOS
FET
LX
EXT/1
EXT/2
PBST
GND
Ta=
25:
PARAMETER RATINGS UNITSSYMBOL
V
IN
Pin Voltage -0.3 ~ 12 VV
IN
V
OUT
Pin Voltage
(FB Pin Voltage)
-0.3 ~ 12
(-0.3 ~ V
IN
+0.3)
V
V
OUT
(V
FB
)
L
X
Pin Voltage V
IN
-12 ~ V
IN
+0.3 VV
LX
P_BST Pin Voltage V
IN
-12 ~ V
IN
+0.3 VP_BST
Other Pin Voltage -0.3 ~ V
IN
+0.3 VV~
L
X
Pin Current 700 mAILX
EXT/1,2 Pin Current ±50 mAI
EXT
/1,2
Storage Temperature -40 ~ +125
:
Tstg
Continuous Total
Power Dissipation 300 mWPd
Operating Ambient
Temperature -30 ~ +80
:
Topr
■AbsoluteMaximumRatings
XC6376/6377
Series
581
5
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XC6376/6377
Series
582
5
XC6376A333SR, XC6377A333SR
XC6376E, XC6376F, XC6377E, XC6377F
Ta=25
:
(V
OUT
=3.3V, F
OSC
=300kHz)
PARAMETER UNITS
Output Voltage V
OUT
1 V3.3833.3003.218
Output Voltage2 V
OUT
2 V
V
OUT
1
+1.5%
V
OUT
1
-0.5%
Soft-Start Time Tss msec16.010.06.0
PFM Duty Ratio (Note2) PFMDTY %352515External components connected, No load.
Efficiency (Note3) EFFI %95Same as V
OUT
1
Minimum Operating Voltage
(UVLO Voltage) V
UVLO
Only C
SS
connected, V
IN
= output programmed voltage x 0.9,
CE= V
IN
, LX OFF voltage when V
IN
drops. 0.9 1.8 V
Circuit Protect Integration Time T
PRO
msec8.05.03.0
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
Time taken for CE to become "L" when V
OUT
changes to 0V
CE "High" Voltage V
CEH
V0.65
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
V
OUT
=0V, Apply voltage to CE and measure EXT/1,2 "L"
CE "Low" Voltage V
CEL
V0.20
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
V
OUT
=0V, Apply voltage to CE and measure EXT/1,2 "H"
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
CE=0V, V
OUT
=V
IN
, EXT/1,2 pull down to 200Ω,
V
EXT
/1,2=V
IN
- 0.4V
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
CE=V
IN
, V
OUT
=output programmed voltage x 0.9,
EXT/1,2 pull up to 200Ω, V
EXT
/1,2=0.4V
EXT/1,2 "H" ON Resistance R
EXTBH
Ω4735
EXT/1,2 "L" ON Resistance R
EXTBL
Ω3729
Maximum Input Voltage V
IN
V10
Input Current I
IN
1.480 mA2.190
Maximum Output Current I
OUT
MAX mA600
µA8655
XC6376
XC6377
External components connected,
V
IN
=V
OUT
x 1.05, No load.
Supply Current
(oscillation stopped) I
DD
26 µA39
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
V
OUT
= V
IN
, V
LX
=V
IN
External components connected,
VIN=output programmed voltage x 1.2,
External components connected, V
IN
=output programmed
voltage x 1.2, I
OUT
=132mA
External components connected, V
IN
=output programmed
voltage x 1.6, (when V
IN
≤ 3.0V, V
IN
=3.0V)
Lx SW ON Resistance R
SWON
0.64 Ω0.85
Stand-by Current I
STB
µA2.51.5Same as I
DD
. CE=0V
%100
Oscillator Frequency
(Note1) F
OSC
kHz345300255
Lx Leak Current I
LXL
µA2.0
External components connected, measuring of EXT/1
waveform, V
IN
=V
OUT
1 +0.3V, I
OUT
=20mA
Maximum Duty Ratio MAXDTY
Same as I
DD
except V
OUT
=output programmed voltage x0.9,
V
LX
=V
IN
-0.2V, pull down LX to 10Ω, CE=V
IN
Same as I
STB
except V
LX
=0V
SYMBOL CONDITIONS MAXMIN TYP
PARAMETER UNITS
V
OUT
Sink Current IV
OUT
L mA1.45
Same as I
STB
, V
OUT
=1.0V
SYMBOL CONDITIONS MAXMIN TYP
Refers to the oscillation frequency during PWM control.
Applies to the XC6377 series only (duty ratio when control changes to PFM)
EFFI = { [(output voltage) x (output current)] ÷ [(input voltage) x (input current)]} x100
Note 1:
Note 2:
Note 3:
The following parameter is to be added:
XC6376C, XC6376F, XC6377C, XC6377F
The following parameter is to be excluded: Circuit Protect Integration Time (T
PRO
)
■ElectricalCharacteristics
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XC6376/6377
Series
583
5
XC6376A503SR, XC6377A503SR
XC6376E, XC6376F, XC6377E, XC6377F
Ta=25
:
(V
OUT
=5.0V, F
OSC
=300kHz)
PARAMETER UNITS
Output Voltage V
OUT
1 V5.1255.0004.875
Output Voltage2 V
OUT
2 V
V
OUT
1
+1.5%
V
OUT
1
-0.5%
Soft-Start Time Tss msec16.010.06.0
PFM Duty Ratio (Note2) PFMDTY %352515External components connected, No load.
Efficiency (Note3) EFFI %95Same as V
OUT
1
Minimum Operating Voltage
(UVLO Voltage) V
UVLO
Only C
SS
connected, V
IN
= output programmed voltage x 0.9,
CE= V
IN
, LX OFF voltage when V
IN
drops. 0.9 1.8 V
Circuit Protect Integration Time T
PRO
msec8.05.03.0
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
Time taken for CE to become "L" when V
OUT
changes to 0V
CE "High" Voltage V
CEH
V0.65
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
V
OUT
=0V, Apply voltage to CE and measure EXT/1,2 "L"
CE "Low" Voltage V
CEL
V0.20
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
V
OUT
=0V, Apply voltage to CE and measure EXT/1,2 "H"
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
CE=0V, V
OUT
=V
IN
, EXT/1,2 pull down to 200Ω,
V
EXT
/1,2=V
IN
- 0.4V
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
CE=V
IN
, V
OUT
=output programmed voltage x 0.9,
EXT/1,2 pull up to 200Ω, V
EXT
/1,2=0.4V
EXT/1,2 "H" ON Resistance R
EXTBH Ω
3224
EXT/1,2 "L" ON Resistance R
EXTBL Ω
2620
Maximum Input Voltage V
IN
V10
Input Current I
IN
2.540 mA3.740
Maximum Output Current I
OUT
MAX mA600
µA11071
XC6376
XC6377
External components connected,
V
IN
=V
OUT
x 1.05, No load.
Supply Current
(oscillation stopped) I
DD
26 µA39
Only C
SS
connected, V
IN
= output programmed voltage x 1.2,
V
OUT
= V
IN
, V
LX
=V
IN
External components connected,
VIN=output programmed voltage x 1.2,
External components connected, V
IN
=output programmed
voltage x 1.2, I
OUT
=200mA
External components connected, V
IN
=output programmed
voltage x 1.6, (when V
IN
≤ 3.0V, V
IN
=3.0V)
Lx SW ON Resistance R
SWON
0.44
Ω
0.58
Stand-by Current I
STB
µA2.51.5Same as I
DD
. CE=0V
%100
Oscillator Frequency
(Note1) F
OSC
kHz345300255
Lx Leak Current I
LXL
µA2.0
External components connected, measuring of EXT/1 waveform,
V
IN
=V
OUT
1 +0.3V, I
OUT
=20mA
Maximum Duty Ratio MAXDTY
Same as I
DD
except V
OUT
=output programmed voltage x0.9,
V
LX
=V
IN
-0.2V, pull down LX to 10Ω, CE=V
IN
Same as I
STB
except V
LX
=0V
SYMBOL CONDITIONS MAXMIN TYP
PARAMETER UNITS
V
OUT
Sink Current IV
OUT
L mA1.85
Same as I
STB
, V
OUT
=1.0V
SYMBOL CONDITIONS MAXMIN TYP
Refers to the oscillation frequency during PWM control.
Applies to the XC6377 series only (duty ratio when control changes to PFM)
EFFI = { [(output voltage) x (output current)]
÷
[(input voltage) x (input current)]} x100
Note 1:
Note 2:
Note 3:
The following parameter is to be added:
XC6376C, XC6376F, XC6377C, XC6377F
The following parameter is to be excluded: Circuit Protect Integration Time (T
PRO
)
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XC6376/6377
Series
584
5
XC6376B103SR, XC6377B103SR Ta=25
:
(V
OUT
=3.0V(when programmed), F
OSC
=300kHz)
PARAMETER UNITS
Output Voltage V
OUT
1 V3.0603.0002.940
Output Voltage2 V
OUT
2 V
V
OUT
1
+1.5%
V
OUT
1
-0.5%
Soft-Start Time Tss msec16.010.06.0
PFM Duty Ratio (Note2) PFMDTY %352515External components connected, No load.
Efficiency (Note3) EFFI %95Same as V
OUT
1
Minimum Operating Voltage
(UVLO Voltage) V
UVLO
Only C
SS
connected.
CE= V
IN
, FB=0.9V, LX OFF voltage when V
IN
drops. 0.9 1.8 V
Circuit Protect Integration Time T
PRO
msec8.05.03.0
Only C
SS
connected, V
IN
= 3.6V
Time taken for CE to become "L" when V
OUT
changes to 0V
CE "High" Voltage V
CEH
V0.65
Only C
SS
connected, V
IN
= 3.6V, FB=0V,
Apply voltage to CE and measure EXT/1,2 "L"
CE "Low" Voltage V
CEL
V0.20
Only C
SS
connected, V
IN
= 3.6V, FB=0V,
Apply voltage to CE and measure EXT/1,2 "H"
Only C
SS
connected,
CE=0V, V
IN
=3.6V, FB=1.2V, EXT/1,2 pull down to 200Ω,
V
EXT
/1,2=V
IN
- 0.4V
Only C
SS
connected,
CE=V
IN
, V
IN
=3.6V, FB=0.9V,
EXT/1,2 pull up to 200Ω, V
EXT
/1,2=0.4V
EXT/1,2 "H" ON Resistance R
EXTBH
Ω5238
EXT/1,2 "L" ON Resistance R
EXTBL
Ω4131
Maximum Input Voltage V
IN
V10
Input Current I
IN
1.320 mA1.950
Maximum Output Current I
OUT
MAX mA500
µA8252
XC6376
XC6377
External components connected,
V
IN
=V
OUT
x 1.05, No load.
Supply Current
(oscillation stopped) I
DD
26 µA39
Only C
SS
connected, V
IN
= 3.6V
FB= 1.2V, V
LX
=V
IN
External components connected, V
IN
=3.6V
External components connected, V
IN
=3.6V,
I
OUT
=120mA
External components connected, V
IN
=4.8V
Lx SW ON Resistance R
SWON
0.69 Ω0.94
Stand-by Current I
STB
µA2.51.5Same as I
DD
. CE=0V
%100
Oscillator Frequency
(Note1) F
OSC
kHz345300255
Lx Leak Current I
LXL
µA2.0
External components connected, measuring of EXT/1 waveform,
V
IN
=V
OUT
1 +0.3V, I
OUT
=20mA
Maximum Duty Ratio MAXDTY
Only C
SS
connected, V
IN
=3.6V, CE=V
IN
, LX pull down to 10Ω
V
LX
=V
IN
- 0.2V, FB=0.9V
Same as I
STB
except V
LX
=0V
SYMBOL CONDITIONS MAXMIN TYP
Refers to the oscillation frequency during PWM control.
Applies to the XC6377 series only (duty ratio when control changes to PFM)
EFFI = { [(output voltage) x (output current)]
÷
[(input voltage) x (input current)]} x100
Note 1:
Note 2:
Note 3:
XC6376D, XC6376D
The following parameter is to be excluded: Circuit Protect Integration Time (T
PRO
)
R
FB
1=400kΩ, R
FB
2=200kΩ, C
FB
=100pF
Peripherals:
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XC6376/6377
Series
585
5
1. Output Voltage Internally Set-up Type (VOUT)
External Components :
L
SD1
C
L
C
SS
C
IN
Note
: 22µH (Sumida CR54, F
OSC
=300kHz)
47µH (Sumida CR75, F
OSC
=180kHz)
10µH (Sumida CR54, F
OSC
=500kHz)
: MA2Q735 (Schottky Diode, Matsushita)
: 10V 47µF (Tantalum capacitor, Nichicon MCE)
: 4700pF (Ceramic capacitor, F
OSC
=300kHz, 180kHz)
0.01µF (Ceramic capacitor, F
OSC
=500kHz)
: 16V 10µF (Tantalum capacitor, Nichicon MCE)
: Please increase capacitance value (C
IN
) when necessary
2. Output Voltage Externally Set-up Type (FB)
External Components :
L
SD1
C
L
C
SS
C
IN
R
FB
C
FB
Note
: 22µH (Sumida CR54, F
OSC
=300kHz)
47µH (Sumida CR75, F
OSC
=180kHz)
10µH (Sumida CR54, F
OSC
=500kHz)
: MA2Q735 (Schottky Diode, Matsushita)
: 10V 47µF (Tantalum capacitor, Nichicon MCE)
: 4700pF (Ceramic capacitor, F
OSC
=300kHz, 180kHz)
0.01µF (Ceramic capacitor, F
OSC
=500kHz)
: 16V 10µF (Tantalum capacitor, Nichicon MCE)
: Please set-up so that R
FB1
÷ R
FB2
= V
OUT
- 1 (V
OUT
= set-up output voltage) and ensure that
R
FB1
+ R
FB2
≤ 2MΩ. N.B. In actual operation please set-up so that the FB pin will be equal to 1.0V
: Please set-up so that { f = 1 ÷ (2π x C
FB
x R
FB1
)} will be in the range of 1 ~ 20kHz (5kHz normal )
e.g. If V
OUT
= 3.0V then R
FB1
= 400kΩ, F
FB2
= 200kΩ, C
FB
= 100pF
: Please increase capacitance value (C
IN
) when necessary
CL
（Tantalum）
CIN
（Tantalum）
1
2
3
4
8
7
6
5
L
VIN
CE/
VOUT
SD1
Css
CL
（Tantalum）
CIN
（Tantalum）
1
2
3
4
8
7
6
5
L
VIN
RFB2
RFB1
FB
CE/
VOUT
SD1
Css
CFB
■TypicalApplicationCircuits
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1. Maximum Output Current IOUTMAX
The maximum output current of a step-down DC/DC converter can be calculated from the values of the switching transistor's ON resistance
(RSWON), the DC resistance of the coil (DCR) and the wiring resistance between the input and output pins (RETC).
IOUTMAX=(VIN - VOUT) ÷(RSWON + DCR + RETC)
The coil's DCR value will be 0.18Ω(max.) with the CR54 22µH (catalog value).
If output current should exceed the above calculated value for IOUTMAX a condition of maximum duty will exist.
Please use coils and Schottky diodes that have an ample output current (IOUT) margin over the stated approved currents and check the coil's
current frequency in actual operation.
2. Board Wiring
Peripherals should be located as close as possible to the IC and should be connected with low impedance traces.
Note that high current levels flow through the VIN - IC - coil - VOUT line. Make the ground pattern as large as possible and connect capacitor
CLbetween the ground pin and the VOUT pin with a low impedance.
3. Integral Circuit Protection
Should the output voltage drop as a result of overload, the IC will operate in a maximum duty state. If the TPRO time (5 msec typ.) is
exceeded the CE pin will be reset to ground level and the soft-start routine will resume.
If the overload condition continues then the following steps will be repeated.
Circuit protection activates - CE pin reset - soft-start routine resumes - circuit protection activates -etc.
As stated, when the current drawn exceeds the maximum output current (IOUTMAX) as calculated above, maximum duty will exist. When the
input/output voltage differential is minimal even a comparatively small output current will trigger the protection circuit so please be careful.
For those customers who require the P-channel power MOSFET to be enabled at any time and the protect circuit to not operate during low
VIN periods, versions of the series without protection are also available (XC6376C, D, F types and XC6377C, D, F types)
Note :
Integral circuit protection performs the basic function of informing external components of the existence of a continuous state of overload in
connection with temporary drops in the level of VOUT (CE). Therefore, should output short to ground level and a state of overload continue,
ample circuit protection cannot be provided. In such cases, as there is the possibility that the IC and/or the peripherals may be damaged, it
is recommended that output be switched off via the CE pin.
4. Soft-start, Chip Enable Circuits (CE Pin)
In order to charge the soft-start capacitor (CSS) at the CE pin, a fixed current of about 1µA has been internally set-up. Therefore, when using
the CE function (stand-by operations) please be aware of the possibilites of leak current from the transistor's open collector (or open drain)
connection. We recommend that a capacitor of at least 100pF be connected. Although the IC will still function with CSS omitted and the CE
pin connected to the VIN pin, there exists the possibility that large overshoot input voltages and/or rush currents will occur when the power is
switched on which may cause instability.
The same problem may also arise if the CE pin is driven from a CMOS output , so it is recommended that the CE pin be driven from an
open collector (or open drain). Should the CE pin be driven from a CMOS output however, a resistor should be fitted between the CE pin
and the output and a soft-start capacitor (CSS) should be connected. Measuring operational stability is also necessary.
Note :
Even if the CE function is not being used, a soft-start capacitor (CSS) of more than 100pF should still be connected.
5. P-Channel Boost Circuit
Attaching a capacitor (CBST) and a diode (SD2) as displayed in the figure right, allows the gate
voltage of an internal P-ch power MOSFET to be driven to a negative voltage value.
Since LXSW ON resistance (RSWON) becomes smaller, the efficiency at high output currents can be
improved. On the other hand, efficiency during light loads will drop due to losses as a result of CBST's
charging and discharging.
CBST : 2200pF (ceramic capacitor)
SD2 : MA729 (Schottky diode, Matsushita)
Note :
The voltage between VIN and P-BST should not exceed 10V (absolute max. 12V).
With higher VIN values, take such countermeasures as clamping or using a 9V Zener diode.
1
2
3
4
8
7
6
5
（ ）
CBST
SD2 ZD
■Directionsforuse
●Notes
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6. EXT / 1, EXT / 2 Pins
As the EXT / 1 and EXT / 2 pins are provided, external transistor drives and various application circuits can be handled.
EXT / 1 follows the same timing pattern as a P-channel power MOSFET ("L" in the ON mode) whereas EXT / 2 functions in a 100 nsec
blank clock timing pattern (N.B. EXT / 2 changes from "H to L" 100 nsec before EXT /1 but 100 nsec after EXT / 1 with "L to H" changes.)
e.g.
The drawing of large output currents can be handled by connecting an external, low ON resistance, P-ch power MOSFET.
In such cases we also recommend that the FET gate be connected to EXT / 1, the source to VIN and the drain to Lx in line with the typical
application circuit examples provided.
The EXT /1 pin can be driven to a gate capacitance of up to 1000pF.
7. U. V. L. O Circuit
Below the minimum operating voltage (VUVLO) operations shut down and, along with the P-ch power MOSFET being set to OFF, Ext /1 and
EXT /2 will be "H" . (If using an external transistor, the transistor will be set to OFF.)
8. VOUT Reset Function
A function that pulls VOUT to ground during stand-by (CE "L") is available (XC6376E).
Note that this function is not available with externally set-up output voltage types (FB).
9. Capacitor CIN
Sudden current changes at ground or power supply that are common to step-down DC/DC converters during switching may cause the IC's
operations to become unstable depending upon the degree to which the IC's power supply voltage changes, which in turn is affected by the
wiring's impedance level.
It is therefore recommended that a power supply ripple rejection use capacitor (CIN) be connected between the IC's VIN and GND pins.
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■TypicalPerformance
Characteristics
(1) OUTPUT VOLTAGE vs. OUTPUT CURRENT
3.0
3.2
3.1
3.3
3.4
3.5
0.1 1 10 100 1000
OutputVoltage:VOUT（V）
OutputCurrent:IOUT（mA）
XC6377A333
8.0V
5.0V
VIN＝3.96V
L＝22μH（CR54）
3.0
3.2
3.1
3.3
3.4
3.5
0.1 1 10 100 1000
OutputVoltage:VOUT（V）
OutputCurrent:IOUT（mA）
XC6376A333
10.0V
VIN＝3.96V,5.0V,8.0V
L＝22μH（CR54）
3.0
3.2
3.1
3.3
3.4
3.5
0.1 1 10 100 1000
OutputVoltage:VOUT（V）
OutputCurrent:IOUT（mA）
XC6377A333
5.0V
8.0V
L＝10μH（CR54）
VIN＝3.96V
3.0
3.2
3.1
3.3
3.4
3.5
0.1 1 10 100 1000
OutputVoltage:VOUT（V）
OutputCurrent:IOUT（mA）
XC6377A333
5.0V
8.0V
L＝47μH（CR105）
VIN＝4.0V
4.4
4.8
4.6
5.0
5.2
5.4
0.1 1 10 100 1000
OutputVoltage:VOUT（V）
OutputCurrent:IOUT（mA）
XC6377A503
8.0V
VIN＝6.0V
L＝22μH（CR54）
10.0V
4.4
4.8
4.6
5.0
5.2
5.4
0.1 1 10 100 1000
OutputVoltage:VOUT（V）
OutputCurrent:IOUT（mA）
XC6376A503
8.0V
6.0V
L＝22μH（CR54）
10.0V
Note: <External component> CIN = 47µF (Tantalum)
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(2) EFFICIENCY vs. OUTPUT CURRENT
0
40
20
60
80
100
0.1 1 10 100 1000
Efficiency:EFFI（%）
OutputCurrent:IOUT（mA）
XC6377A333
5.0V
VIN＝3.96V
L＝22μH（CR54）
8.0V
0
40
20
60
80
100
0.1 1 10 100 1000
Efficiency:EFFI（%）
OutputCurrent:IOUT（mA）
XC6376A333
5.0V
VIN＝3.96V
L＝22μH（CR54）
8.0V
10.0V
0
40
20
60
80
100
0.1 1 10 100 1000
Efficiency:EFFI（%）
OutputCurrent:IOUT（mA）
XC6377A333
5.0V
VIN＝3.96V
L＝10μH（CR54）
8.0V
0
40
20
60
80
100
0.1 1 10 100 1000
Efficiency:EFFI（%）
OutputCurrent:IOUT（mA）
XC6377A333
5.0V
VIN＝4.0V
L＝47μH（CR105）
8.0V
0
40
20
60
80
100
0.1 1 10 100 1000
Efficiency:EFFI（%）
OutputCurrent:IOUT（mA）
XC6377A503
10.0V
VIN＝6.0V
L＝22μH（CR54）
8.0V
0
40
20
60
80
100
0.1 1 10 100 1000
Efficiency:EFFI（%）
OutputCurrent:IOUT（mA）
XC6376A503
10.0V
6.0V
L＝22μH（CR54）
8.0V
Note: <External component> CIN = 47µF (Tantalum)
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(3)
OUTPUT VOLTAGE vs. AMBIENT TEMPERATURE
(4)
SUPPLY CURRENT vs. AMBIENT TEMPERATURE
(5)
STAND-BY CURRENT vs. AMBIENT TEMPERATURE
(6)
LXSWITCH ON RESISTANCE vs. AMBIENT TEMPERATURE
(7)
OSCILLATION FREQUENCY vs. AMBIENT TEMPERATURE
(8)
PFM DUTY RATIO vs. AMBIENT TEMPERATURE
3.20
3.25
3.30
3.35
3.40
−
40
−
20 0 20 80
OutputVoltage:VOUT1
,
VOUT2（V）
AmbientTemp.:Ta（℃）
XC6377A333
40 60
VOUT1
VOUT2
0
15
20
25
30
−
40
−
20 0 20 80
SupplyCurrent:IDD（μA ）
AmbientTemp.:Ta（℃）
XC6377A333
40 60
10
5
0.0
0.2
0.3
0.4
0.5
−
40
−
20 0 20 80
Stand-ByCurrent:ISTB（µA）
AmbientTemp.:Ta（℃）
XC6377A333
40 60
0.1
0.0
0.6
0.8
1.0
1.2
−
40
−
20 0 20 80
LXSwitchOnResistance:RSWON（Ω）
AmbientTemp.:Topr（℃）
XC6377A333
40 60
0.4
0.2
200
250
300
350
400
−
40
−
20 0 20 80
OscillationFrequency
;FOSC
:（kHz）
AmbientTemp.:Ta（℃）
XC6377A333
40 60
0
20
30
40
50
−
40
−
20 0 20 80
PfmDutyRatio:PFMDTY（％）
AmbientTemp.:Ta（℃）
40 60
10
XC6377A333
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(9) EFFICIENCY vs. AMBIENT TEMPERATURE (10)
MINIMUM OPERATING VOLTAGE vs. AMBIENT TEMPERATURE
(11)
SOFT START TIME vs. AMBIENT TEMPERATURE
(12)
CE "L" VOLTAGE vs. AMBIENT TEMPERATURE
(13)
CE "H" VOLTAGE vs. AMBIENT TEMPERATURE
50
70
80
90
100
−
40
−
20 0 20 80
Efficiency:EFFI（%）
AmbientTemp.:Ta（℃）
XC6377A333
40 60
60
0.8
1.2
1.4
1.6
1.8
−
40
−
20 0 20 80
Min.OperatingVoltage:VUVLO（V）
AmbientTemp.:Ta（℃）
XC6377A333
40 60
1.0
0
4
8
12
16
−
40
−
20 0 20 80
SoftStartTime:TSS（V）
AmbientTemp.:Ta（℃）
XC6377A333
40 60
0.0
0.4
0.6
0.8
1.0
−
40
−
20 0 20 80
CE"L"Voltage
:
VCEL（V）
AmbientTemp.:Ta（℃）
40 60
0.2
XC6377A333
0.0
0.4
0.6
0.8
1.0
−
40
−
20 0 20 80
CE"H"Voltage:VCEH（V）
AmbientTemp.:Ta（℃）
XC6377A333
40 60
0.2
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(14) LOAD TRANSIENT RESPONSE
2.9
3.1
3.0
3.2
3.3
3.4
OutputVoltage:VOUT（V）
Time（0.5msec/div）
XC6377A333
VIN＝4V,IOUT＝100μA→100mA
0
300
200
100
400
500
OutputCurrent:IOUT（mA）
100mA
OutputCurrent
OutputVoltage
100
μ
A
2.9
3.1
3.0
3.2
3.3
3.4
OutputVoltage:VOUT（V）
Time（20msec/div）
XC6377A333
VIN＝4V,IOUT＝100mA→100μA
0
300
200
100
400
500
OutputCurrent:IOUT（mA）
100mA
100
μ
A
OutputCurrent
OutputVoltage
2.9
3.1
3.0
3.2
3.3
3.4
OutputVoltage:V
OUT
（V）
Time（0.5msec/div）
XC6377A333
VIN＝4V,IOUT＝100μA→300mA
0
600
400
200
800
1000
OutputCurrent:I
OUT
（mA）
300mA
100
μ
A
OutputCurrent
OutputVoltage
2.9
3.1
3.0
3.2
3.3
3.4
OutputVoltage:VOUT（V）
Time（20msec/div）
XC6377A333
VIN＝4V,IOUT＝300mA→100μA
0
600
400
200
800
1000
OutputCurrent:IOUT（mA）
300mA
100
μ
A
OutputCurrent
OutputVoltage
2.9
3.1
3.0
3.2
3.3
3.4
OutputVoltage:VOUT（V）
Time（0.5msec/div）
XC6377A333
VIN＝4V,IOUT＝10mA→300mA
0
600
400
200
800
1000
OutputCurrent:IOUT（mA）
300mA
10
m
A
OutputCurrent
OutputVoltage
2.9
3.1
3.0
3.2
3.3
3.4
OutputVoltage:VOUT（V）
Time（0.5msec/div）
XC6377A333
VIN＝4V,IOUT＝300mA→10mA
0
600
400
200
800
1000
OutputCurrent:IOUT（mA）
300mA
10
m
A
OutputCurrent
OutputVoltage
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External Components :
L :22µH(Sumida CR54,FOSC = 300kHz)
SD1 :U2FWJ44N(Diode, Toshiba)
CL:10V 47µF+47µF(Tantalum capacitor, Nichicon MCE)
CSS :4700pF(Ceramic capacitor)
CIN :16V 47µF(Tantalum capacitor, Nichicon MCE) or
0.1µF (Ceramic capacitor)
Tr :XP162A11C0RR or XP132A1275SR (Torex)
Note:In order to reduce impedance we recommend use of a capacitor (CIN) with a large capacitance value or a ceramic capacitor with
a low ESR value.
Please insert a by-pass capacitor of more than 0.1µF between pin Numbers 1 and 3.
■TypicalApplicationCircuits
1. Large Current Output Circuit (P-channel power MOSFET external)
CL
（Tantalum）
CIN
（Tantalum）
1
2
3
4
8
7
6
5
L
VIN
CE/
VOUT
SD1
Css
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