Series
PWM Controlled,PWM/PFM Switchable Step‐down DC/DC Converters
◆P-Channel Power MOSFET Built-in
■Applications
◆Maximum Output Current : 500mA
●Electronic Information Organizers
◆Output Voltage Range
: 1.5~6.0V
●Palmtops
◆Oscillator Frequency
: 300kHz
◆Maximum Duty Ratio
: 100%
◆High Efficiency
: 95%
●Cellular and portable phones
●Portable Audio Systems
●Various Multi-function Power Supplies
◆SOP-8 Package
5
■General Description
■Features
The XC6376/77 series are step-down DC/DC converters with built-in Pchannel 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.
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
U.V.L.O and protection are built-in.
■Typical Application Circuit
VIN
CIN
（Tantalum）
8
2
7
SD1
XC6377A333
L＝22μH（CR54）
100
L
3
6
4
5
Css
VOUT
CL
（Tantalum）
VIN＝3.96V
Efficiency:EFFI（%）
CE/
1
■Typical Performance
Characteristic
80
60
5.0V
8.0V
40
20
0
0.1
1
10
100
1000
Output Current:IOUT（mA）
577
XC6376/6377
Series
■Pin Configuration
VIN 1
8 LX
PIN
NUMBER
PIN
NAME
1
VIN
Power supply input
FUNCTION
EXT/2 2
7 EXT/1
P_BST 3
6 GND
2
EXT/2
External drive pin 2
("L" when Pch MOSFET ON)
CE 4
5 VOUT
3
P_BST
P-ch gate boost
4
CE
Chip enable
Soft-start capacitor connection
5
VOUT
(FB)
Output voltage monitor
(FB=externally set-up type)
6
GND
Ground
7
EXT/1
External drive pin 1
("L" when P-ch MOSFET ON)
8
LX
P-ch power MOSFET switch
SOP-8
（TOP VIEW）
5
■Pin Assignment
■Product Classification
●Selection Guide
START
Output Voltage Internally set-up (VOUT)
Reset Function - Yes
Protect Circuit - Yes
XC6376E,XC6377E
Protect Circuit - No
XC6376F,XC6377F
Reset Function - No
Protect Circuit - Yes
XC6376A,XC6377A
Protect Circuit - No
XC6376C,XC6377C
Output Voltage Externally set-up (FB)
578
Protect Circuit - Yes
XC6376B,XC6377B
Protect Circuit - No
XC6376D,XC6377D
XC6376/6377
Series
●Ordering Information
XC6376①②③④⑤⑥
XC6376 Series
SYMBOL
①
PWM Control
VOUT/FB
VOUT RESET FUNCTION
INTEGRAL CIRCUIT PROTECTION
A
VOUT
NO
YES
B
FB
-
YES
C
VOUT
NO
NO
D
FB
-
NO
E
VOUT
YES
YES
F
VOUT
YES
NO
②
Output voltage e.g. 3.0V output : (②=3, ③=0)
FB products (B,D types) : (②=1, ③=0)
③
3
Oscillator frequency 300kHz
5
Oscillator frequency 500kHz
2
Oscillator frequency 180kHz
⑤
S
Package SOP-8
⑥
R
Embossed Tape : Standard Feed
④
L
: 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
0.2 -0.1
+0.05
1.27±0.03 0.4±0.1
5.0 +0.5
-0.2
4.2±0.4
0∼0.25
0.35∼1.0
579
XC6376/6377
Series
■Marking
6 7 8
Y A A
1 2 3 4 5
qwertyui
EX：XC6376A303SR
LOGO MARK
w
q
SOP-8
(TOP VIEW)
7
6
A
3
0
3
e
r
t
y
u
i
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
LX
P-ch POWER MOS
FET
VOUT
Protection
Phase
Compensation
+
+
PWM
Comparator
-
CE
CE
Vref with
Soft Start,
Error Amp.
-
EXT/1
Buffer,
Driver
EXT/2
P_BST
Ramp Wave
Generator,
OSC
PWM/PFM
Controller
GND
XC6376, XC6377 Series B,D types (FB)
VIN
LX
P-ch POWER MOS
FET
FB
Protection
Phase
Compensation
+
+
-
CE
CE
Vref with
Soft Start,
580
PWM
Comparator
Error Amp.
-
EXT/1
Buffer,
Driver
EXT/2
P_BST
PWM/PFM
Controller
Ramp Wave
Generator,
OSC
GND
XC6376/6377
Series
XC6376, XC6377 Series E,F types (VOUT, VOUT rest function)
VIN
P-ch POWER MOS
FET
VOUT
Protection
Phase
Compensation
+
+
PWM
Comparator
-
CE
Error Amp.
CE
Vref with
Soft Start
LX
-
Ramp Wave
Generator,
OSC
PWM/PFM
Controller
EXT/1
Buffer,
Driver
EXT/2
P_BST
GND
5
■Absolute Maximum Ratings
PARAMETER
SYMBOL
Ta=25:
RATINGS
UNITS
VIN Pin Voltage
VIN
-0.3 ~ 12
V
VOUT Pin Voltage
(FB Pin Voltage)
VOUT
(VFB)
-0.3 ~ 12
(-0.3 ~ VIN +0.3)
V
LX Pin Voltage
VLX
VIN -12 ~ VIN +0.3
V
P_BST Pin Voltage
P_BST
VIN -12 ~ VIN +0.3
V
Other Pin Voltage
V~
-0.3 ~ VIN +0.3
V
LX Pin Current
ILX
700
mA
EXT/1,2 Pin Current
IEXT/1,2
±50
mA
Continuous Total
Power Dissipation
Pd
300
mW
Operating Ambient
Temperature
Topr
-30 ~ +80
:
Storage Temperature
Tstg
-40 ~ +125
:
581
XC6376/6377
Series
■Electrical Characteristics
XC6376A333SR, XC6377A333SR
5
(V OUT =3.3V, F OSC =300kHz)
Ta=25:
PARAMETER
SYMBOL
CONDITIONS
MIN
Output Voltage
VOUT1
External components connected, VIN=output programmed
voltage x 1.2, IOUT=132mA
3.218 3.300 3.383
V
Output Voltage2
VOUT2
External components connected, VIN=output programmed
voltage x 1.6, (when VIN ≤ 3.0V, VIN =3.0V)
VOUT1
-0.5%
VOUT1
+1.5%
V
Maximum Input Voltage
VIN
Maximum Output Current
IOUTMAX
Input Current
IIN
External components connected,
VIN=VOUT x 1.05, No load.
Supply Current
(oscillation stopped)
External components connected,
VIN=output programmed voltage x 1.2,
TYP
MAX UNITS
10
V
600
mA
1.480 2.190
XC6376
mA
55
86
µA
IDD
Only CSS connected, VIN = output programmed voltage x 1.2,
VOUT= VIN, VLX=VIN
26
39
µA
Stand-by Current
ISTB
Same as IDD. CE=0V
1.5
2.5
µA
Lx SW ON Resistance
RSWON
Same as IDD except VOUT=output programmed voltage x0.9,
VLX=VIN-0.2V, pull down LX to 10Ω, CE=VIN
0.64
0.85
Ω
Lx Leak Current
2.0
µA
XC6377
ILXL
Same as ISTB except VLX=0V
Oscillator Frequency
(Note1)
FOSC
External components connected, measuring of EXT/1
waveform, VIN=VOUT1 +0.3V, IOUT=20mA
255
300
345
kHz
Maximum Duty Ratio
PFM Duty Ratio (Note2)
MAXDTY
PFMDTY
External components connected, No load.
100
15
25
35
%
%
Efficiency (Note3)
EFFI
Same as VOUT 1
Minimum Operating Voltage
(UVLO Voltage)
VUVLO
Only CSS connected, VIN = output programmed voltage x 0.9,
CE= VIN, LX OFF voltage when VIN drops.
Soft-Start Time
Tss
Circuit Protect Integration Time
TPRO
Only CSS connected, VIN = output programmed voltage x 1.2,
Time taken for CE to become "L" when VOUT changes to 0V
CE "High" Voltage
VCEH
Only CSS connected, VIN = output programmed voltage x 1.2,
VOUT=0V, Apply voltage to CE and measure EXT/1,2 "L"
CE "Low" Voltage
VCEL
Only CSS connected, VIN = output programmed voltage x 1.2,
VOUT=0V, Apply voltage to CE and measure EXT/1,2 "H"
EXT/1,2 "H" ON Resistance
REXTBH
Only CSS connected, VIN = output programmed voltage x 1.2,
CE=0V, VOUT=VIN, EXT/1,2 pull down to 200Ω,
VEXT/1,2=VIN - 0.4V
EXT/1,2 "L" ON Resistance
REXTBL
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
95
0.9
%
1.8
V
6.0
10.0
16.0
msec
3.0
5.0
8.0
msec
0.65
V
0.20
V
35
47
Ω
29
37
Ω
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
VOUT Sink Current
IVOUTL
CONDITIONS
Same as ISTB, VOUT=1.0V
XC6376C, XC6376F, XC6377C, XC6377F
The following parameter is to be excluded: Circuit Protect Integration Time (TPRO)
582
MIN
1.45
TYP
MAX UNITS
mA
XC6376/6377
Series
XC6376A503SR, XC6377A503SR
(V OUT =5.0V, F OSC =300kHz)
Ta=25:
PARAMETER
SYMBOL
CONDITIONS
MIN
Output Voltage
VOUT1
External components connected, VIN=output programmed
voltage x 1.2, IOUT=200mA
4.875 5.000 5.125
V
Output Voltage2
VOUT2
External components connected, VIN=output programmed
voltage x 1.6, (when VIN ≤ 3.0V, VIN =3.0V)
VOUT1
-0.5%
VOUT1
+1.5%
V
Maximum Input Voltage
VIN
External components connected,
VIN=output programmed voltage x 1.2,
Maximum Output Current
IOUTMAX
Input Current
IIN
External components connected,
VIN=VOUT x 1.05, No load.
Supply Current
(oscillation stopped)
IDD
Stand-by Current
ISTB
TYP
MAX UNITS
10
V
600
mA
2.540 3.740
XC6376
mA
71
110
µA
Only CSS connected, VIN = output programmed voltage x 1.2,
VOUT= VIN, VLX=VIN
26
39
µA
Same as IDD. CE=0V
1.5
2.5
µA
Same as IDD except VOUT=output programmed voltage x0.9,
VLX=VIN-0.2V, pull down LX to 10Ω, CE=VIN
0.44
0.58
Ω
2.0
µA
XC6377
Lx SW ON Resistance
RSWON
Lx Leak Current
ILXL
Same as ISTB except VLX=0V
Oscillator Frequency
(Note1)
FOSC
External components connected, measuring of EXT/1 waveform,
VIN=VOUT1 +0.3V, IOUT=20mA
Maximum Duty Ratio
PFM Duty Ratio (Note2)
MAXDTY
PFMDTY
Efficiency (Note3)
External components connected, No load.
EFFI
Same as VOUT 1
Minimum Operating Voltage
(UVLO Voltage)
VUVLO
Only CSS connected, VIN = output programmed voltage x 0.9,
CE= VIN, LX OFF voltage when VIN drops.
Soft-Start Time
Tss
Circuit Protect Integration Time
TPRO
CE "High" Voltage
255
300
345
kHz
100
15
25
35
%
%
95
0.9
5
%
1.8
V
6.0
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
3.0
5.0
8.0
msec
VCEH
Only CSS connected, VIN = output programmed voltage x 1.2,
VOUT=0V, Apply voltage to CE and measure EXT/1,2 "L"
0.65
CE "Low" Voltage
VCEL
Only CSS connected, VIN = output programmed voltage x 1.2,
VOUT=0V, Apply voltage to CE and measure EXT/1,2 "H"
EXT/1,2 "H" ON Resistance
REXTBH
Only CSS connected, VIN = output programmed voltage x 1.2,
CE=0V, VOUT=VIN, EXT/1,2 pull down to 200Ω,
VEXT/1,2=VIN - 0.4V
EXT/1,2 "L" ON Resistance
REXTBL
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
V
0.20
V
24
32
Ω
20
26
Ω
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
VOUT Sink Current
IVOUTL
CONDITIONS
Same as ISTB, VOUT=1.0V
MIN
1.85
TYP
MAX UNITS
mA
XC6376C, XC6376F, XC6377C, XC6377F
The following parameter is to be excluded: Circuit Protect Integration Time (TPRO)
583
XC6376/6377
Series
XC6376B103SR, XC6377B103SR
5
(V OUT =3.0V(when programmed), F OSC =300kHz)
CONDITIONS
SYMBOL
Output Voltage
VOUT1
External components connected, VIN=3.6V,
IOUT=120mA
2.940 3.000 3.060
V
Output Voltage2
VOUT2
External components connected, VIN=4.8V
VOUT1
-0.5%
V
MIN
TYP
MAX UNITS
10
V
External components connected, VIN=3.6V
500
mA
mA
VOUT1
+1.5%
Maximum Input Voltage
VIN
Maximum Output Current
IOUTMAX
Input Current
IIN
External components connected,
VIN=VOUT x 1.05, No load.
52
82
µA
Supply Current
(oscillation stopped)
IDD
Only CSS connected, VIN = 3.6V
FB= 1.2V, VLX=VIN
26
39
µA
Stand-by Current
ISTB
Same as IDD. CE=0V
1.5
2.5
µA
Only CSS connected, VIN=3.6V, CE=VIN, LX pull down to 10Ω
VLX=VIN - 0.2V, FB=0.9V
0.69
0.94
Ω
2.0
µA
300
345
kHz
25
35
%
%
Lx SW ON Resistance
RSWON
Lx Leak Current
1.320 1.950
XC6376
XC6377
ILXL
Same as ISTB except VLX=0V
Oscillator Frequency
(Note1)
FOSC
External components connected, measuring of EXT/1 waveform, 255
VIN=VOUT1 +0.3V, IOUT=20mA
Maximum Duty Ratio
PFM Duty Ratio (Note2)
MAXDTY
PFMDTY
Efficiency (Note3)
External components connected, No load.
EFFI
Same as VOUT 1
Minimum Operating Voltage
(UVLO Voltage)
VUVLO
Only CSS connected.
CE= VIN, FB=0.9V, LX OFF voltage when VIN drops.
Soft-Start Time
Tss
Circuit Protect Integration Time
TPRO
Only CSS connected, VIN = 3.6V
Time taken for CE to become "L" when VOUT changes to 0V
CE "High" Voltage
VCEH
Only CSS connected, VIN = 3.6V, FB=0V,
Apply voltage to CE and measure EXT/1,2 "L"
CE "Low" Voltage
VCEL
Only CSS connected, VIN = 3.6V, FB=0V,
Apply voltage to CE and measure EXT/1,2 "H"
EXT/1,2 "H" ON Resistance
REXTBH
Only CSS connected,
CE=0V, VIN=3.6V, FB=1.2V, EXT/1,2 pull down to 200Ω,
VEXT/1,2=VIN - 0.4V
EXT/1,2 "L" ON Resistance
REXTBL
Only CSS connected,
CE=VIN, VIN=3.6V, FB=0.9V,
EXT/1,2 pull up to 200Ω, VEXT/1,2=0.4V
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)
584
Ta=25:
PARAMETER
100
15
95
0.9
%
1.8
V
6.0
10.0
16.0
msec
3.0
5.0
8.0
msec
0.65
V
0.20
V
38
52
Ω
31
41
Ω
XC6376/6377
Series
■Typical Application Circuits
1. Output Voltage Internally Set-up Type (VOUT)
VIN
CE/
CIN
（Tantalum）
1
8
2
7
3
6
4
5
SD1
L
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)
CL : 10V 47µF (Tantalum capacitor, Nichicon MCE)
CSS : 4700pF (Ceramic capacitor, FOSC=300kHz, 180kHz)
0.01µF (Ceramic capacitor, FOSC=500kHz)
CIN : 16V 10µF (Tantalum capacitor, Nichicon MCE)
5
Note : Please increase capacitance value (CIN) when necessary
2. Output Voltage Externally Set-up Type (FB)
VIN
CIN
（Tantalum）
CE/
1
8
2
7
3
6
4
5
SD1
CFB
L
RFB1
VOUT
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)
CL : 10V 47µF (Tantalum capacitor, Nichicon MCE)
CSS : 4700pF (Ceramic capacitor, FOSC=300kHz, 180kHz)
0.01µF (Ceramic capacitor, FOSC=500kHz)
CIN : 16V 10µF (Tantalum capacitor, Nichicon MCE)
RFB : Please set-up so that RFB1 ÷ RFB2 = VOUT - 1 (VOUT = set-up output voltage) and ensure that
RFB1 + RFB2 ≤ 2MΩ. N.B. In actual operation please set-up so that the FB pin will be equal to 1.0V
CFB : 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
585
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.
5
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 LX SW 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.
586
CBST
1
8
2
7
3
6
4
5
SD2
（ ）ZD
XC6376/6377
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.
It is therefore recommended that a power supply ripple rejection use capacitor (CIN) be connected between the IC's VIN and GND pins.
5
587
XC6376/6377
Series
■Typical Performance Characteristics
(1) OUTPUT VOLTAGE vs. OUTPUT CURRENT
XC6377A333
XC6376A333
L＝22μH（CR54）
5.0V
3.4
VIN＝3.96V
3.3
3.2
8.0V
3.1
3.0
0.1
1
10
100
L＝22μH（CR54）
3.5
Output Voltage:VOUT（V）
Output Voltage:VOUT（V）
3.5
10.0V
3.4
3.3
VIN＝3.96V,5.0V,8.0V
3.2
3.1
3.0
0.1
1000
Output Current:IOUT（mA）
1
10
100
1000
Output Current:IOUT（mA）
5
XC6377A333
XC6377A333
L＝10μH（CR54）
3.4
VIN＝3.96V
5.0V
3.3
3.2
8.0V
3.1
3.0
0.1
1
10
100
L＝47μH（CR105）
3.5
Output Voltage:VOUT（V）
Output Voltage:VOUT（V）
3.5
5.0V
3.4
VIN＝4.0V
3.3
3.2
3.1
8.0V
3.0
0.1
1000
Output Current:IOUT（mA）
XC6377A503
8.0V
5.0
VIN＝6.0V
4.8
4.6
10
100
1000
Output Current:IOUT（mA）
Note: <External component> CIN = 47µF (Tantalum)
588
100
1000
L＝22μH（CR54）
5.4
Output Voltage:VOUT（V）
Output Voltage:VOUT（V）
10.0V
5.2
1
10
XC6376A503
L＝22μH（CR54）
5.4
4.4
0.1
1
Output Current:IOUT（mA）
5.2
5.0
6.0V
4.8
8.0V
10.0V
4.6
4.4
0.1
1
10
100
Output Current:IOUT（mA）
1000
XC6376/6377
Series
(2) EFFICIENCY vs. OUTPUT CURRENT
XC6377A333
XC6376A333
L＝22μH（CR54）
100
L＝22μH（CR54）
100
5.0V
60
Efficiency:EFFI（%）
Efficiency:EFFI（%）
VIN＝3.96V
80
5.0V
8.0V
40
20
0
80
VIN＝3.96V
60
10.0V
8.0V
40
20
0
0.1
1
10
100
1000
0.1
Output Current:IOUT（mA）
XC6377A333
100
1000
5
80
60
VIN＝3.96V
5.0V
8.0V
20
L＝47μH（CR105）
100
Efficiency:EFFI（%）
100
Efficiency:EFFI（%）
10
XC6377A333
L＝10μH（CR54）
40
1
Output Current:IOUT（mA）
0
80
60
5.0V
40
8.0V
VIN＝4.0V
20
0
0.1
1
10
100
1000
0.1
Output Current:IOUT（mA）
1
10
100
1000
Output Current:IOUT（mA）
XC6377A503
XC6376A503
L＝22μH（CR54）
100
L＝22μH（CR54）
100
Efficiency:EFFI（%）
Efficiency:EFFI（%）
6.0V
80
8.0V
60
10.0V
VIN＝6.0V
40
20
0
80
60
10.0V
40
8.0V
20
0
0.1
1
10
100
1000
Output Current:IOUT（mA）
0.1
1
10
100
1000
Output Current:IOUT（mA）
Note: <External component> CIN = 47µF (Tantalum)
589
XC6376/6377
Series
(3) OUTPUT VOLTAGE vs. AMBIENT TEMPERATURE
(4) SUPPLY CURRENT vs. AMBIENT TEMPERATURE
XC6377A333
3.40
30
Supply Current:IDD（μA）
Output Voltage:VOUT1 , VOUT2（V）
XC6377A333
3.35
VOUT1
3.30
VOUT2
3.25
3.20
25
20
15
10
5
0
−40
−20
0
20
40
60
80
−40
−20
Ambient Temp.:Ta（℃）
(5) STAND-BY CURRENT vs. AMBIENT TEMPERATURE
XC6377A333
Stand-By Current:ISTB（µA）
0.4
0.3
0.2
0.1
0.0
−20
0
20
40
60
80
1.0
0.8
0.6
0.4
0.2
0.0
−40
−20
0
20
40
60
80
(8) PFM DUTY RATIO vs. AMBIENT TEMPERATURE
XC6377A333
XC6377A333
400
Pfm Duty Ratio:PFMDTY（％）
Oscillation Frequency;FOSC:（kHz）
80
Ambient Temp.:Topr（℃）
(7) OSCILLATION FREQUENCY vs. AMBIENT TEMPERATURE
350
300
250
200
50
40
30
20
10
0
−20
0
20
40
60
Ambient Temp.:Ta（℃）
590
60
1.2
Ambient Temp.:Ta（℃）
−40
40
XC6377A333
0.5
−40
20
(6) LX SWITCH ON RESISTANCE vs. AMBIENT TEMPERATURE
LX Switch On Resistance:RSWON（Ω）
5
0
Ambient Temp.:Ta（℃）
80
−40
−20
0
20
40
60
Ambient Temp.:Ta（℃）
80
XC6376/6377
Series
(9) EFFICIENCY vs. AMBIENT TEMPERATURE
(10) MINIMUM OPERATING VOLTAGE vs. AMBIENT TEMPERATURE
XC6377A333
XC6377A333
Min. Operating Voltage:VUVLO（V）
Efficiency:EFFI（%）
100
90
80
70
60
50
−40
−20
0
20
40
60
80
1.8
1.6
1.4
1.2
1.0
0.8
−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
XC6377A333
XC6377A333
1.0
CE "L" Voltage:VCEL（V）
Soft Start Time:TSS（V）
16
5
12
8
4
0
0.8
0.6
0.4
0.2
0.0
−40
−20
0
20
40
60
80
Ambient Temp.:Ta（℃）
−40
−20
0
20
40
60
80
Ambient Temp.:Ta（℃）
(13) CE "H" VOLTAGE vs. AMBIENT TEMPERATURE
XC6377A333
CE "H"Voltage:VCEH（V）
1.0
0.8
0.6
0.4
0.2
0.0
−40
−20
0
20
40
60
80
Ambient Temp.:Ta（℃）
591
XC6376/6377
Series
(14) LOAD TRANSIENT RESPONSE
400
3.2
300
3.1
200
2.9
Output Current
100mA
100
100μA
3.3
3.2
3.0
600
Output Current
400
300mA
3.0
200
Output Voltage:VOUT（V）
800
Output Current:IOUT（mA）
Output Voltage:VOUT（V）
Output Voltage
3.2
2.9
800
Output Voltage
3.2
3.1
600
400
Output Current
300mA
3.0
200
0
Time（20msec/div）
XC6377A333
XC6377A333
VIN＝4V , IOUT＝10mA→300mA
3.3
800
3.2
600
Output Current
400
300mA
3.0
200
Output Voltage:VOUT（V）
Output Voltage
VIN＝4V , IOUT＝300mA→10mA
3.4
1000
Output Current:IOUT（mA）
Output Voltage:VOUT（V）
1000
3.3
Time（0.5msec/div）
1000
3.3
800
Output Voltage
3.2
3.1
600
Output Current
300mA
3.0
400
200
10mA
10mA
2.9
0
Time（0.5msec/div）
592
VIN＝4V , IOUT＝300mA→100μA
2.9
0
3.1
0
100μA
100μA
3.4
100
100μA
3.4
1000
3.1
100mA
XC6377A333
VIN＝4V , IOUT＝100μA→300mA
3.3
200
Output Current
Time（20msec/div）
XC6377A333
3.4
300
3.1
Time（0.5msec/div）
5
400
Output Voltage
2.9
0
500
Output Current:IOUT（mA）
3.0
Output Voltage:VOUT（V）
3.3
Output Current:IOUT（mA）
Output Voltage
VIN＝4V , IOUT＝100mA→100μA
3.4
500
2.9
0
Time（0.5msec/div）
Output Current:IOUT（mA）
3.4
Output Voltage:VOUT（V）
XC6377A333
VIN＝4V , IOUT＝100μA→100mA
Output Current:IOUT（mA）
XC6377A333
XC6376/6377
Series
■Typical Application Circuits
1. Large Current Output Circuit (P-channel power MOSFET external)
VIN
CE/
CIN
（Tantalum）
1
8
2
7
3
6
4
5
SD1
L
Css
VOUT
CL
（Tantalum）
External Components :
L
:22µH(Sumida CR54,FOSC = 300kHz)
SD1
CL
:U2FWJ44N(Diode, Toshiba)
:10V 47µF+47µF(Tantalum capacitor, Nichicon MCE)
CSS
CIN
:4700pF(Ceramic capacitor)
:16V 47µF(Tantalum capacitor, Nichicon MCE) or
Tr
:XP162A11C0RR or XP132A1275SR (Torex)
5
0.1µF (Ceramic capacitor)
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