XC6377BXX5SR [TOREX]
PWM Controlled PWM/PFM Switchable Step-down DC/DC Converters; PWM控制的PWM / PFM切换降压型DC / DC转换器
| 型号： | XC6377BXX5SR |
| 厂家： | 
Torex Semiconductor |
| 描述： | PWM Controlled PWM/PFM Switchable Step-down DC/DC Converters |
| 文件： | 总17页 (文件大小：302K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
05S_3XC6376/77 02.09.12 15:20 ページ 577
Series
PWM Controlled,PWM/PFM Switchable Step‐down DC/DC Converters
ꢁP-Channel Power MOSFET Built-in
■Applications
ꢀElectronic Information Organizers
ꢁMaximum Output Current : 500mA
ꢀPalmtops
ꢁOutput Voltage Range
ꢁOscillator Frequency
ꢁMaximum Duty Ratio
ꢁHigh Efficiency
: 1.5~6.0V
: 300kHz
: 100%
ꢀCellular and portable phones
ꢀPortable Audio Systems
ꢀVarious Multi-function Power Supplies
: 95%
ꢁSOP-8 Package
5
■General Description
■Features
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.
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
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.
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
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, 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
U.V.L.O and protection are built-in.
■Typical Application Circuit
■Typical Performance
Characteristic
VIN
SD1
XC6377A333
1
2
3
4
8
7
6
5
�
L＝22μH（CR54）�
CIN�
（Tantalum）�
100
80
L
CE/
VIN＝3.96V
VOUT
60
5.0V
CL�
（Tantalum）�
8.0V
Css
40
20
0
0.1
1
10
100
1000
Output Current:IOUT（mA）�
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XC6376/6377
Series
■Pin Configuration
■Pin Assignment
PIN
PIN
VIN
EXT/2
P_BST
CE
LX
1
2
3
4
8
7
6
5
FUNCTION
NUMBER
NAME
EXT/1
GND
VOUT
1
V
IN
Power supply input
External drive pin 2
("L" when Pch MOSFET ON)
2
3
EXT/2
P_BST
P-ch gate boost
Chip enable
Soft-start capacitor connection
4
CE
SOP-8�
（TOP VIEW）�
Output voltage monitor
V
OUT
5
6
7
8
(FB=externally set-up type)
(FB)
GND
Ground
External drive pin 1
("L" when P-ch MOSFET ON)
EXT/1
LX
P-ch power MOSFET switch
■Product Classification
ꢀSelection Guide
5
�
START
Output Voltage Internally set-up (VOUT)
Reset Function - Yes
Protect Circuit - Yes
Protect Circuit - No
XC6376E,XC6377E
XC6376F,XC6377F
Reset Function - No
XC6376A,XC6377A
XC6376C,XC6377C
Protect Circuit - Yes
Protect Circuit - No
Output Voltage Externally set-up (FB)
Protect Circuit - Yes
Protect Circuit - No
XC6376B,XC6377B
XC6376D,XC6377D
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XC6376/6377
Series
ꢀOrdering Information
XC6376①②③④⑤⑥�
XC6376 Series
PWM Control
SYMBOL
V
OUT/FB
OUT
V
OUT RESET FUNCTION
INTEGRAL CIRCUIT PROTECTION
A
B
V
NO
-
YES
YES
NO
FB
C
V
OUT
NO
-
①�
D
FB
NO
E
F
V
OUT
YES
YES
YES
NO
VOUT
②�
③�
Output voltage e.g. 3.0V output : (
②
=3,
③=0)
FB products (B,D types) : ( =1,
②
③
=0)
3
Oscillator frequency 300kHz
Oscillator frequency 500kHz
Oscillator frequency 180kHz
Package SOP-8
④�
5
2
⑤�
⑥�
S
R
L
Embossed Tape : Standard Feed
: Reverse Feed
5
XC6377①②③④⑤⑥�
XC6377 Series
PWM/PFM switching control
(same as XC6376 series)
■Packaging Information
ꢀSOP-8
+0.4
6.1
-0.3
1.5±0.1
4.2±0.4
0～0.25
0.35～1.0
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XC6376/6377
Series
■Marking
qwertyui
EX：XC6376A303SR
LOGO MARK
7
6
A
3
0
3
w
q
e
r
t
y
u
i
SOP-8
(TOP VIEW)
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.
■Block Diagram
XC6376, XC6377 Series A,C types (VOUT)
5
VIN
L
X
P-ch POWER MOS�
FET
VOUT
Phase�
Compensation
Protection
+
EXT/1
EXT/2
PWM�
Comparator
+
Buffer,�
Driver
-
CE
-
Error Amp.
CE�
P_BST
GND
Vref with �
Ramp Wave�
Generator,�
OSC
PWM/PFM�
Controller
Soft Start,
XC6376, XC6377 Series B,D types (FB)
VIN
FB
L
X
P-ch POWER MOS�
FET
Phase�
Compensation
Protection
EXT/1
EXT/2
PWM�
Comparator
+
+
Buffer,�
Driver
-
CE
-
Error Amp.
CE�
P_BST
GND
Vref with �
Soft Start,
Ramp Wave�
Generator,�
OSC
PWM/PFM�
Controller
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XC6376/6377
Series
XC6376, XC6377 Series E,F types (VOUT, VOUT rest function)
VIN
L
X
P-ch POWER MOS�
FET
VOUT
Phase�
Compensation
Protection
EXT/1
EXT/2
PWM�
Comparator
+
+
Buffer,�
Driver
-
CE
-
Error Amp.
CE�
P_BST
GND
Vref with �
Soft Start
Ramp Wave�
Generator,�
OSC
PWM/PFM�
Controller
5
■Absolute Maximum Ratings
Ta=25:
PARAMETER
SYMBOL
RATINGS
-0.3 ~ 12
UNITS
V
IN Pin Voltage
V
IN
V
V
-0.3 ~ 12
(-0.3 ~ VIN +0.3)
V
OUT Pin Voltage
(FB Pin Voltage)
VOUT
(VFB
)
L
X
Pin Voltage
V
LX
V
IN -12 ~ VIN +0.3
V
V
P_BST Pin Voltage
Other Pin Voltage
P_BST
VIN -12 ~ VIN +0.3
V~
-0.3 ~ VIN +0.3
700
V
L
X
Pin Current
ILX
mA
EXT/1,2 Pin Current
IEXT/1,2
50
mA
Continuous Total
Power Dissipation
Pd
300
mW
Operating Ambient
Temperature
Topr
Tstg
-30 ~ +80
:
:
Storage Temperature
-40 ~ +125
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XC6376/6377
Series
■Electrical Characteristics
XC6376A333SR, XC6377A333SR
(VOUT=3.3V, FOSC=300kHz)
Ta=25
:
PARAMETER
Output Voltage
SYMBOL
CONDITIONS
MIN TYP MAX UNITS
External components connected, VIN=output programmed
voltage x 1.2, IOUT=132mA
V
V
OUT
1
2
3.218 3.300 3.383
V
V
-0.5%
OUT
1
VOUT1
+1.5%
External components connected, VIN=output programmed
voltage x 1.6, (when VIN ≤ 3.0V, VIN =3.0V)
Output Voltage2
OUT
V
V
Maximum Input Voltage
Maximum Output Current
VIN
10
External components connected,
VIN=output programmed voltage x 1.2,
I
OUTMAX
600
mA
2.190 mA
XC6376
1.480
55
External components connected,
Input Current
IIN
V
IN=VOUT x 1.05, No load.
XC6377
86
µA
µA
µA
Ω
Supply Current
(oscillation stopped)
Only CSS connected, VIN = output programmed voltage x 1.2,
39
26
1.5
I
DD
V
OUT= VIN, VLX=VIN
Stand-by Current
Lx SW ON Resistance
Lx Leak Current
I
STB
Same as IDD. CE=0V
2.5
0.85
2.0
345
Same as IDD except VOUT=output programmed voltage x0.9,
R
SWON
0.64
VLX=VIN-0.2V, pull down LX to 10Ω, CE=VIN
I
LXL
µA
kHz
Same as ISTB except VLX=0V
External components connected, measuring of EXT/1
waveform, VIN=VOUT1 +0.3V, IOUT=20mA
Oscillator Frequency
(Note1)
255
300
F
OSC
5
Maximum Duty Ratio
PFM Duty Ratio (Note2)
Efficiency (Note3)
MAXDTY
PFMDTY External components connected, No load.
EFFI Same as VOUT
100
15
%
%
%
25
95
35
1
Minimum Operating Voltage
(UVLO Voltage)
Only CSS connected, VIN = output programmed voltage x 0.9,
CE= VIN, LX OFF voltage when VIN drops.
V
UVLO
0.9
6.0
3.0
1.8
V
Soft-Start Time
Tss
10.0 16.0 msec
Only CSS connected, VIN = output programmed voltage x 1.2,
Time taken for CE to become "L" when VOUT changes to 0V
Circuit Protect Integration Time
T
PRO
5.0
8.0
msec
Only CSS connected, VIN = output programmed voltage x 1.2,
CE "High" Voltage
CE "Low" Voltage
V
CEH
0.65
V
V
Ω
V
OUT=0V, Apply voltage to CE and measure EXT/1,2 "L"
Only CSS connected, VIN = output programmed voltage x 1.2,
OUT=0V, Apply voltage to CE and measure EXT/1,2 "H"
V
CEL
0.20
47
V
Only CSS connected, VIN = output programmed voltage x 1.2,
35
29
EXT/1,2 "H" ON Resistance
EXT/1,2 "L" ON Resistance
R
EXTBH
CE=0V, VOUT=VIN, EXT/1,2 pull down to 200Ω,
VEXT/1,2=VIN - 0.4V
Only CSS connected, VIN = output programmed voltage x 1.2,
CE=VIN, VOUT=output programmed voltage x 0.9,
EXT/1,2 pull up to 200Ω, VEXT/1,2=0.4V
37
Ω
R
EXTBL
Note 1: Refers to the oscillation frequency during PWM control.
Note 2: Applies to the XC6377 series only (duty ratio when control changes to PFM)
Note 3: EFFI = { [(output voltage) x (output current)] ÷ [(input voltage) x (input current)]} x100
XC6376E, XC6376F, XC6377E, XC6377F
The following parameter is to be added:
PARAMETER
SYMBOL
IVOUT
CONDITIONS
Same as ISTB, VOUT=1.0V
MIN TYP MAX UNITS
1.45 mA
V
OUT Sink Current
L
XC6376C, XC6376F, XC6377C, XC6377F
The following parameter is to be excluded: Circuit Protect Integration Time (TPRO
)
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XC6376/6377
Series
XC6376A503SR, XC6377A503SR
(VOUT=5.0V, FOSC=300kHz)
CONDITIONS
Ta=25
:
PARAMETER
SYMBOL
MIN TYP MAX UNITS
External components connected, VIN=output programmed
voltage x 1.2, IOUT=200mA
Output Voltage
V
V
OUT
1
2
4.875 5.000 5.125
V
V
OUT1
VOUT1
External components connected, VIN=output programmed
voltage x 1.6, (when VIN ≤ 3.0V, VIN =3.0V)
Output Voltage2
OUT
V
V
-0.5%
+1.5%
Maximum Input Voltage
Maximum Output Current
VIN
10
External components connected,
VIN=output programmed voltage x 1.2,
I
OUTMAX
600
mA
3.740 mA
XC6376
2.540
71
External components connected,
Input Current
IIN
V
IN=VOUT x 1.05, No load.
XC6377
110
µA
µA
µA
Ω
Supply Current
(oscillation stopped)
Only CSS connected, VIN = output programmed voltage x 1.2,
39
26
1.5
I
DD
VOUT= VIN, VLX=VIN
Stand-by Current
Lx SW ON Resistance
Lx Leak Current
I
STB
Same as IDD. CE=0V
2.5
Same as IDD except VOUT=output programmed voltage x0.9,
0.58
2.0
R
SWON
0.44
VLX=VIN-0.2V, pull down LX to 10Ω, CE=VIN
I
LXL
µA
kHz
Same as ISTB except VLX=0V
Oscillator Frequency
(Note1)
External components connected, measuring of EXT/1 waveform,
255
300
345
F
OSC
5
VIN=VOUT1 +0.3V, IOUT=20mA
Maximum Duty Ratio
PFM Duty Ratio (Note2)
Efficiency (Note3)
MAXDTY
PFMDTY External components connected, No load.
EFFI Same as VOUT
100
15
%
%
%
25
95
35
1
Minimum Operating Voltage
(UVLO Voltage)
Only CSS connected, VIN = output programmed voltage x 0.9,
CE= VIN, LX OFF voltage when VIN drops.
V
UVLO
0.9
6.0
3.0
1.8
V
Soft-Start Time
Tss
10.0 16.0 msec
Only CSS connected, VIN = output programmed voltage x 1.2,
Time taken for CE to become "L" when VOUT changes to 0V
Circuit Protect Integration Time
T
PRO
5.0
8.0
msec
V
Only CSS connected, VIN = output programmed voltage x 1.2,
CE "High" Voltage
CE "Low" Voltage
V
CEH
0.65
VOUT=0V, Apply voltage to CE and measure EXT/1,2 "L"
Only CSS connected, VIN = output programmed voltage x 1.2,
OUT=0V, Apply voltage to CE and measure EXT/1,2 "H"
V
CEL
0.20
32
V
V
Only CSS connected, VIN = output programmed voltage x 1.2,
24
20
Ω
EXT/1,2 "H" ON Resistance
EXT/1,2 "L" ON Resistance
R
EXTBH
CE=0V, VOUT=VIN, EXT/1,2 pull down to 200Ω,
VEXT/1,2=VIN - 0.4V
Only CSS connected, VIN = output programmed voltage x 1.2,
CE=VIN, VOUT=output programmed voltage x 0.9,
EXT/1,2 pull up to 200Ω, VEXT/1,2=0.4V
26
Ω
R
EXTBL
Note 1: Refers to the oscillation frequency during PWM control.
Note 2: Applies to the XC6377 series only (duty ratio when control changes to PFM)
Note 3:
÷ [(input voltage) x (input current)]} x100
EFFI = { [(output voltage) x (output current)]
XC6376E, XC6376F, XC6377E, XC6377F
The following parameter is to be added:
PARAMETER
SYMBOL
IVOUT
CONDITIONS
Same as ISTB, VOUT=1.0V
MIN TYP MAX UNITS
1.85 mA
V
OUT Sink Current
L
XC6376C, XC6376F, XC6377C, XC6377F
The following parameter is to be excluded: Circuit Protect Integration Time (TPRO
)
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XC6376/6377
Series
XC6376B103SR, XC6377B103SR
(VOUT=3.0V(when programmed), FOSC=300kHz)
CONDITIONS
Ta=25
:
PARAMETER
SYMBOL
MIN TYP MAX UNITS
External components connected, VIN=3.6V,
Output Voltage
V
V
OUT
1
2
2.940 3.000 3.060
V
V
I
OUT=120mA
V
OUT1
VOUT1
Output Voltage2
OUT
External components connected, VIN=4.8V
-0.5%
+1.5%
Maximum Input Voltage
Maximum Output Current
V
IN
10
V
I
OUTMAX External components connected, VIN=3.6V
500
mA
1.950 mA
XC6376
XC6377
1.320
52
External components connected,
Input Current
IIN
V
IN=VOUT x 1.05, No load.
82
µA
µA
µA
Ω
Supply Current
(oscillation stopped)
Only CSS connected, VIN = 3.6V
FB= 1.2V, VLX=VIN
39
26
1.5
I
DD
Stand-by Current
Lx SW ON Resistance
Lx Leak Current
I
STB
Same as IDD. CE=0V
2.5
0.94
2.0
345
Only CSS connected, VIN=3.6V, CE=VIN, LX pull down to 10Ω
LX=VIN - 0.2V, FB=0.9V
R
SWON
0.69
V
I
LXL
µA
kHz
Same as ISTB except VLX=0V
Oscillator Frequency
(Note1)
External components connected, measuring of EXT/1 waveform,
255
300
F
OSC
VIN=VOUT1 +0.3V, IOUT=20mA
5
Maximum Duty Ratio
PFM Duty Ratio (Note2)
Efficiency (Note3)
MAXDTY
PFMDTY External components connected, No load.
EFFI Same as VOUT
100
15
%
%
%
25
95
35
1
Minimum Operating Voltage
(UVLO Voltage)
Only CSS connected.
V
UVLO
0.9
6.0
3.0
1.8
V
CE= VIN, FB=0.9V, LX OFF voltage when VIN drops.
Soft-Start Time
Tss
10.0 16.0 msec
Only CSS connected, VIN = 3.6V
Time taken for CE to become "L" when VOUT changes to 0V
Circuit Protect Integration Time
T
PRO
5.0
8.0
msec
Only CSS connected, VIN = 3.6V, FB=0V,
CE "High" Voltage
CE "Low" Voltage
V
CEH
0.65
V
V
Ω
Apply voltage to CE and measure EXT/1,2 "L"
Only CSS connected, VIN = 3.6V, FB=0V,
Apply voltage to CE and measure EXT/1,2 "H"
V
CEL
0.20
52
Only CSS connected,
38
31
EXT/1,2 "H" ON Resistance
EXT/1,2 "L" ON Resistance
R
EXTBH
CE=0V, VIN=3.6V, FB=1.2V, EXT/1,2 pull down to 200Ω,
VEXT/1,2=VIN - 0.4V
Only CSS connected,
CE=VIN, VIN=3.6V, FB=0.9V,
EXT/1,2 pull up to 200Ω, VEXT/1,2=0.4V
41
Ω
R
EXTBL
Peripherals:
RFB1=400kΩ, RFB2=200kΩ, CFB=100pF
Note 1: Refers to the oscillation frequency during PWM control.
Note 2: Applies to the XC6377 series only (duty ratio when control changes to PFM)
Note 3: EFFI = { [(output voltage) x (output current)]
÷ [(input voltage) x (input current)]} x100
XC6376D, XC6376D
The following parameter is to be excluded: Circuit Protect Integration Time (TPRO
)
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XC6376/6377
Series
■Typical Application Circuits
1. Output Voltage Internally Set-up Type (VOUT)
VIN
SD1
1
2
3
4
8
7
6
5
CIN�
（Tantalum）�
L
CE/
VOUT
CL�
（Tantalum）�
Css
External Components :
L
: 22µH (Sumida CR54, FOSC=300kHz)
47µH (Sumida CR75, FOSC=180kHz)
10µH (Sumida CR54, FOSC=500kHz)
SD1 : MA2Q735 (Schottky Diode, Matsushita)
5
C
C
L
: 10V 47µF (Tantalum capacitor, Nichicon MCE)
SS : 4700pF (Ceramic capacitor, FOSC=300kHz, 180kHz)
0.01µF (Ceramic capacitor, FOSC=500kHz)
IN : 16V 10µF (Tantalum capacitor, Nichicon MCE)
C
Note : Please increase capacitance value (CIN) when necessary
2. Output Voltage Externally Set-up Type (FB)
VIN
SD1
1
2
3
4
8
7
6
CIN�
（Tantalum）�
CFB
L
RFB1
CE/
VOUT
5
FB
Css
RFB2
CL�
（Tantalum）�
External Components :
L
: 22µH (Sumida CR54, FOSC=300kHz)
47µH (Sumida CR75, FOSC=180kHz)
10µH (Sumida CR54, FOSC=500kHz)
SD1 : MA2Q735 (Schottky Diode, Matsushita)
C
C
L
: 10V 47µF (Tantalum capacitor, Nichicon MCE)
SS : 4700pF (Ceramic capacitor, FOSC=300kHz, 180kHz)
0.01µF (Ceramic capacitor, FOSC=500kHz)
IN : 16V 10µF (Tantalum capacitor, Nichicon MCE)
C
R
FB : Please set-up so that RFB1 ÷ RFB2 = VOUT - 1 (VOUT = set-up output voltage) and ensure that
R
FB1 + RFB2 ≤ 2MΩ. N.B. In actual operation please set-up so that the FB pin will be equal to 1.0V
C
FB : Please set-up so that { f = 1 ÷ (2π x CFB x RFB1)} will be in the range of 1 ~ 20kHz (5kHz normal )
e.g. If VOUT = 3.0V then RFB1 = 400kΩ, FFB2 = 200kΩ, CFB = 100pF
Note : Please increase capacitance value (CIN) when necessary
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XC6376/6377
Series
■Directions for use
ꢀNotes
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
CL between 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.
5
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
CBST
voltage of an internal P-ch power MOSFET to be driven to a negative voltage value.
Since LX SW ON resistance (RSWON) becomes smaller, the efficiency at high output currents can be
1
2
3
4
8
7
6
5
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.
SD2
ZD
（ꢀ）�
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Series
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.
5
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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XC6376/6377
Series
■Typical Performance Characteristics
(1) OUTPUT VOLTAGE vs. OUTPUT CURRENT
XC6377A333
XC6376A333
�
�
L＝22μH（CR54）�
L＝22μH（CR54）�
3.5
3.5
3.4
3.3
3.2
3.1
10.0V
5.0V
3.4
V
IN＝3.96V
3.3
3.2
3.1
V
IN＝3.96V,5.0V,8.0V
8.0V
3.0
3.0
0.1
1
10
100
1000
0.1
1
10
100
1000
Output Current:IOUT（mA）�
Output Current:IOUT（mA）�
5
XC6377A333
XC6377A333
�
�
L＝10μH（CR54）�
L＝47μH（CR105）�
3.5
3.4
3.3
3.2
3.1
3.5
3.4
3.3
3.2
3.1
5.0V
5.0V
V
IN＝3.96V
V
IN＝4.0V
8.0V
8.0V
100
3.0
0.1
3.0
0.1
1
10
100
1000
1
10
1000
Output Current:IOUT（mA）�
Output Current:IOUT（mA）�
XC6377A503
XC6376A503
�
L＝22μH（CR54）�
�
L＝22μH（CR54）�
5.4
5.2
5.0
4.8
4.6
5.4
5.2
5.0
4.8
4.6
10.0V
8.0V
6.0V
VIN＝6.0V
8.0V
10.0V
4.4
4.4
0.1
1
10
100
1000
0.1
1
10
100
1000
Output Current:IOUT（mA）�
Output Current:IOUT（mA）�
Note: <External component> CIN = 47µF (Tantalum)
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XC6376/6377
Series
(2) EFFICIENCY vs. OUTPUT CURRENT
XC6377A333
XC6376A333
�
�
L＝22μH（CR54）�
L＝22μH（CR54）�
100
100
80
5.0V
VIN＝3.96V
80
60
40
20
VIN＝3.96V
60
5.0V
10.0V
8.0V
8.0V
40
20
0
0
0.1
1
10
100
1000
0.1
1
10
100
1000
Output Current:IOUT（mA）�
Output Current:IOUT（mA）�
5
XC6377A333
XC6377A333
�
�
L＝10μH（CR54）�
L＝47μH（CR105）�
100
80
60
40
20
100
80
60
V
IN＝3.96V
5.0V
8.0V
5.0V
8.0V
40
VIN＝4.0V
20
0
0
0.1
1
10
100
1000
0.1
1
10
100
1000
Output Current:IOUT（mA）�
Output Current:IOUT（mA）�
XC6377A503
XC6376A503
�
�
L＝22μH（CR54）�
L＝22μH（CR54）�
100
80
60
40
20
100
80
6.0V
8.0V
60
10.0V
10.0V
V
IN＝6.0V
40
8.0V
20
0
0
0.1
1
10
100
1000
0.1
1
10
100
1000
Output Current:IOUT（mA）�
Output Current:IOUT（mA）�
Note: <External component> CIN = 47µF (Tantalum)
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XC6376/6377
Series
(3) OUTPUT VOLTAGE vs. AMBIENT TEMPERATURE
(4) SUPPLY CURRENT vs. AMBIENT TEMPERATURE
XC6377A333
XC6377A333
3.40
30
25
20
15
10
5
3.35
V
OUT1
3.30
3.25
V
OUT2
3.20
0
－
40
－
20
0
20
40
60
80
－
40
－
20
0
20
40
60
80
Ambient Temp.:Ta（℃）�
Ambient Temp.:Ta（℃）�
(5) STAND-BY CURRENT vs. AMBIENT TEMPERATURE
(6) LX SWITCH ON RESISTANCE vs. AMBIENT TEMPERATURE
5
XC6377A333
XC6377A333
0.5
1.2
1.0
0.8
0.6
0.4
0.2
0.4
0.3
0.2
0.1
0.0
0.0
－
40
－
20
0
20
40
60
80
－
40
－
20
0
20
40
60
80
Ambient Temp.:Ta（℃）�
Ambient Temp.:Top（r ℃）�
(7) OSCILLATION FREQUENCY vs. AMBIENT TEMPERATURE
(8) PFM DUTY RATIO vs. AMBIENT TEMPERATURE
XC6377A333
XC6377A333
400
50
40
30
20
10
350
300
250
200
0
－
40
－
20
0
20
40
60
80
－
40
－
20
0
20
40
60
80
Ambient Temp.:Ta（℃）�
Ambient Temp.:Ta（℃）�
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Series
(9) EFFICIENCY vs. AMBIENT TEMPERATURE
(10) MINIMUM OPERATING VOLTAGE vs. AMBIENT TEMPERATURE
XC6377A333
XC6377A333
100
1.8
1.6
1.4
1.2
1.0
90
80
70
60
50
0.8
－
40
－
20
0
20
40
60
80
－
40
－
20
0
20
40
60
80
Ambient Temp.:Ta（℃）�
Ambient Temp.:Ta（℃）�
(11) SOFT START TIME vs. AMBIENT TEMPERATURE
(12) CE "L" VOLTAGE vs. AMBIENT TEMPERATURE
5
XC6377A333
XC6377A333
16
1.0
0.8
0.6
0.4
0.2
12
8
4
0
0.0
－
40
－
20
0
20
40
60
80
－
40
－
20
0
20
40
60
80
Ambient Temp.:Ta（℃）�
Ambient Temp.:Ta（℃）�
(13) CE "H" VOLTAGE vs. AMBIENT TEMPERATURE
XC6377A333
1.0
0.8
0.6
0.4
0.2
0.0
－
40
－
20
0
20
40
60
80
Ambient Temp.:Ta（℃）�
591
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XC6376/6377
Series
(14) LOAD TRANSIENT RESPONSE
XC6377A333
XC6377A333
�
�
VIN＝4V , IOUT＝100μA→100mA
3.4
VIN＝4V , IOUT＝100mA→100μA
3.4
3.3
3.2
3.1
3.0
500
500
Output Voltage
3.3
400
300
200
100
400
300
200
100
Output Voltage
3.2
3.1
Output Current
Output Current
3.0
100mA
100mA
100
100μA
μ
A
2.9
2.9
0
0
Time（0.5msec/div）�
Time（20msec/div）�
5
XC6377A333
XC6377A333
�
�
V
IN＝4V , IOUT＝100μA→300mA
VIN＝4V , IOUT＝300mA→100μA
3.4
3.3
3.2
3.1
3.0
3.4
3.3
3.2
3.1
3.0
1000
800
600
400
200
1000
800
600
400
200
Output Voltage
Output Voltage
Output Current
300mA
Output Current
300mA
100μA
100μA
2.9
2.9
0
0
Time（0.5msec/div）�
Time（20msec/div）�
XC6377A333
XC6377A333
�
�
VIN＝4V , IOUT＝10mA→300mA
VIN＝4V , IOUT＝300mA→10mA
3.4
3.3
3.2
3.1
3.0
3.4
3.3
3.2
3.1
3.0
1000
800
600
400
200
1000
800
600
400
200
Output Voltage
�
Output Voltage
Output Current
Output Current
300mA
300mA
10mA
10mA
2.9
2.9
0
0
Time（0.5msec/div）�
Time（0.5msec/div）�
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XC6376/6377
Series
■Typical Application Circuits
1. Large Current Output Circuit (P-channel power MOSFET external)
VIN
1
2
3
4
8
7
6
5
SD1
CIN�
（Tantalum）�
L
CE/
VOUT
CL�
（Tantalum）�
Css
External Components :
L
:22µH(Sumida CR54,FOSC = 300kHz)
SD1
CL
:U2FWJ44N(Diode, Toshiba)
5
:10V 47µF+47µF(Tantalum capacitor, Nichicon MCE)
:4700pF(Ceramic capacitor)
CSS
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.
593
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