XC9272 Series
ETR05057-003
Ultra Low Quiescent Current Synchronous Step-Down PFM DC/DC Converter for Low Output Voltage
☆GreenOperation compatible
■GENERAL DESCRIPTION
XC9272 series are Ultra Low Quiescent Current synchronous-rectification for Low Output Voltage type PFM step down
DC/DC converters with a built-in 0.4Ω (TYP.) Pch driver and 0.4Ω (TYP.) Nch synchronous switching transistor, designed to
allow the use of ceramic capacitor.
PFM control enables a low quiescent current, making these products ideal for battery operated devices that require high
efficiency and long battery life.
Only inductor, CIN and CL capacitors are needed as external parts to make a step down DC/DC circuit.
Operation voltage range is from 2.0V to 6.0V. This product has fixed output voltage from 0.6V to 0.95V(accuracy: ±20mV) in
increments of 0.05V.
During stand-by, all circuits are shutdown to reduce consumption to as low as 0.1μA(TYP.) or less.
With the built-in UVLO (Under Voltage Lock Out) function, the internal P-channel MOS driver transistor is forced OFF when
input voltage gets lower than UVLO detection voltage. Besides, XC9272 series has UVLO release voltage of 1.8V (Typ.).
The product with CL discharge function, XC9272B type, can discharge CL capacitor during stand-by mode due to the internal
resistance by turning on the internal switch between VOUT -GND. This enables output voltage restored to GND level fast.
■APPLICATIONS
■FEATURES
●
Electric devices with GPS
●
Wearable devices
●
Energy Harvest devices
●
Backup power supply circuits
●
Devices with 1 Lithium cell
Input Voltage Range
:
2.0V~6.0V
Output Voltage Setting
:
0.6V~0.95V (±20mV, 0.05V step increments)
Output Current
:
50mA
Driver Transistor
:
0.4Ω (Pch Driver Tr)
0.4Ω (Nch Synchronous rectifier Switch Tr)
Supply Current
:
0.50μA @ VOUT(T)=0.7V (TYP.)
Control Method
:
PFM control
High Speed Transient
PFM Switching Current
:
:
50mV (VIN=3.6V, VOUT=0.7V, IOUT=10μA→50mA)
180mA
Function
:
Short Protection function
CL Discharge(XC9272B type)
UVLO function
Ceramic Capacitor Compatible
Operation Ambient Temperature
:
-40~+85℃
Package
:
SOT-25, USP-6EL
Environmentally Friendly
:
EU RoHS compliant, Pb Free
■TYPICAL APPLICATION CIRCUIT
■TYPICAL PERFORMANCE
CHARACTERISTICS
●Efficiency vs. Output Current
XC9272A071xR-G(VOUT=0.7V)
L=10μH(VLF302512M-100M),CIN =10μF(LMK107BJ106MA),
CL=22μF(JMK107BJ226MA)
100
CIN
(Ceramic)
L
VIN
LX
VOUT
CE
GND
VIN=2.0V
VOUT
CL
(Ceramic)
Ef f iciency : EFFI (%)
VIN
80
60
VIN=3.6V
40
20
0
0.01
0.1
1
10
100
Output Current : I OUT (mA)
1/24
XC9272 Series
■ BLOCK DIAGRAM
XC9272A Type
PFM Comparator Unit
VOUT
CFB
RFB1
Short
protection
RFB2
Current
Sense
PFM
Comparator
FB +
CE
CE Controller Logic
PFM
Controller
Synch
Buffer
Driver
VREF
LX
VDD
GND
UVLO
VIN start up
Controller
VIN
* Diodes inside the circuit are an ESD protection diode and a parasitic diode.
XC9272B Type
PFM Comparator Unit
VOUT
CFB
RFB1
Short
protection
CL
Discharge
RFB2
Current
Sense
PFM
Comparator
FB +
CE Controller Logic
CE
VREF
PFM
Controller
Synch
Buffer
Driver
LX
VDD
VIN
UVLO
VIN start up
Controller
* Diodes inside the circuit are an ESD protection diode and a parasitic diode.
2/24
GND
XC9140 (Design Target)
XC9272
Series
■PRODUCT CLASSIFICATION
●Ordering information
XC9272①②③④⑤⑥-⑦
DESIGNATOR
①
Product Type
②③
Output Voltage
④
Output Voltage Type
⑤⑥-⑦
(*1)
ITEM
(*1)
Packages (Order Unit)
SYMBOL
DESCRIPTION
A
Without CL Discharge
B
With CL Discharge
06 ~ 09
Output Voltage : e.g. VOUT=0.7V⇒②=0, ③=7
Output Voltage Range: 0.6V~0.95V (0.05V step)
1
Output Voltage {x.x0V} (the 2nd decimal place is “0”)
B
4R-G
Output Voltage {x.x5V} (the 2nd decimal place is “5”)
USP-6EL (3,000pcs/Reel)
MR-G
SOT-25 (3,000pcs/Reel)
The “-G” suffix denotes Halogen and Antimony free as well as being fully EU RoHS compliant.
3/24
XC9272 Series
■PIN CONFIGURATION
LX
VOUT
5
4
1
2
3
VIN
GND
CE
VIN 6
1 LX
NC 5
2 GND
CE 4
3 VOUT
USP-6EL
(BOTTOM VIEW)
SOT-25
(TOP VIEW)
* The dissipation pad for the USP-6EL package should be solder-plated in reference
mount pattern and metal masking so as to enhance mounting strength and heat release.
The mount pattern should be connected to GND pin (No.2).
■PIN ASSIGNMENT
PIN NUMBER
USP-6EL
SOT-25
1
2
3
4
5
6
PIN NAME
FUNCTIONS
LX
GND
VOUT
CE
NC
VIN
Switching
Ground
Output Voltage
Chip Enable
No Connection
Power Input
5
2
4
3
1
■ CE PIN FUNCTION
PIN NAME
CE
SIGNAL
STATUS
H
Operation (All Series)
L
Standby (All Series)
* Please do not leave the CE pin open.
■ABSOLUTE MAXIMUM RATINGS
PARAMETER
Ta=25˚C
SYMBOL
RATINGS
UNITS
VIN Pin Voltage
LX Pin Voltage
VIN
VLX
-0.3 ~ +7.0
-0.3 ~ VIN+0.3 or +7.0 (*1)
V
V
VOUT Pin Voltage
CE Pin Voltage
VOUT
VCE
-0.3 ~ VIN+0.3 or +7.0 (*1)
-0.3 ~ +7.0
V
V
LX Pin Current
ILX
1000
mA
SOT-25
Power Dissipation
USP-6EL
(DAF)
Operating Ambient Temperature
Storage Temperature
Pd
Topr
Tstg
250
600 (40mm x 40mm Standard board) (*2)
120
750 (40mm x 40mm Standard board) (*2)
-40 ~ +85
-55 ~ +125
* All voltages are described based on the GND.
(*1)
The maximum value is the lower of either VIN + 0.3 or +7.0.
The power dissipation figure shown is PCB mounted and is for reference only.
The mounting condition is please refer to PACKAGING INFORMATION.
(*2)
4/24
mW
˚C
˚C
XC9140 (Design Target)
XC9272
Series
■ELECTRICAL CHARACTERISTICS
●XC9272A Type, without CL discharge function
PARAMETER
SYMBOL
Input Voltage
VIN
Ta=25˚C
CONDITIONS
-
MIN.
TYP.
MAX.
UNITS
CIRCUIT
2.0
-
6.0
V
①
V
②
Resistor connected with LX pin.
Output Voltage
VOUT(E) (*2)
Voltage which LX pin changes “L” to “H” level
E1
while VOUT is decreasing.
VCE=VIN, VOUT=0V. Resistor connected with LX pin.
UVLO Release Voltage
VUVLO(E)
1.65
1.8
1.95
V
②
0.1
0.15
0.23
V
②
VIN=VCE=2.0V, VOUT=VOUT(T)+0.5V (*1), LX=Open.
-
0.5
0.8
μA
③
Voltage which LX pin changes “L” to “H” level
while VIN is increasing.
UVLO Hysteresis
Voltage
Supply Current
VCE=VIN, VOUT=0V. Resistor connected with LX pin.
VHYS(E)
VUVLO(E) - Voltage which LX pin changes “H” to “L”
level while VIN is decreasing.
Iq
Standby Current
ISTB
VIN=5.0V, VCE=VOUT=0V, LX=Open.
-
0.1
1.0
μA
③
LX SW “H” Leak Current
ILEAKH
VIN=5.0V, VCE=VOUT=0V, VLX=0V.
-
0.1
1.0
μA
③
LX SW “L” Leak Current
ILEAKL
VIN=5.0V, VCE=VOUT=0V, VLX=5.0V.
-
0.1
1.0
μA
③
115
180
250
mA
①
-
85
-
%
①
PFM Switching Current
Efficiency (*3)
LX SW “Pch”
ON Resistance (*4)
LX SW “Nch”
ON Resistance
Output Voltage
Temperature
Characteristics
IPFM
EFFI
VIN=VCE=VOUT(T)+2.0V
(*1)
, IOUT=10mA.
VIN=VCE=3.6V,
VOUT(T)=0.7V (*1), IOUT=30mA.
RLXP
VIN=VCE=5.0V, VOUT=0V, ILX=50mA.
-
0.4
0.65
Ω
④
RLXN
VIN=VCE=5.0V.
-
0.4 (*5)
-
Ω
-
-40℃≦Topr≦85℃.
-
±100
-
ppm/℃
②
1.2
-
6.0
V
⑤
GND
-
0.3
V
⑤
ΔVOUT/
(VOUT・ΔTopr)
VOUT=0V. Resistor connected with LX pin.
CE “High” Voltage
VCEH
Voltage which LX pin changes “L” to “H” level while
VCE=0.2→1.5V.
VOUT=0V. Resistor connected with LX pin.
CE “Low” Voltage
VCEL
Voltage which LX pin changes “H” to “L” level while
VCE=1.5→0.2V.
CE “High” Current
ICEH
VIN=VCE=5.0V, VOUT=0V, LX=Open.
-0.1
-
0.1
μA
⑤
CE “Low” Current
ICEL
VIN=5.0V, VCE=VOUT=0V, LX=Open.
-0.1
-
0.1
μA
⑤
0.14
0.3
0.48
V
②
Short Protection
Threshold Voltage
Resistor connected with LX pin.
VSHORT
Voltage which LX pin changes “H” to “L” level while
VOUT= VOUT(T)+0.1V→0V(*1).
Unless otherwise stated, VIN=VCE=5.0V
(*1)
VOUT(T)=Nominal Output Voltage
(*2)
VOUT(E)=Effective Output Voltage
The actual output voltage value VOUT(E) is the PFM comparator threshold voltage in the IC.
Therefore, the DC/DC circuit output voltage, including the peripheral components, is boosted by the ripple voltage average value.
Please refer to the characteristic example.
(*3)
EFFI=[{ (Output Voltage)×(Output Current)] / [(Input Voltage)×(Input Current)}]×100
(*4)
LX SW “Pch” ON resistance = (VIN – VLX pin measurement voltage) / 50mA
(*5) )
Designed value
5/24
XC9272 Series
■ELECTRICAL CHARACTERISTICS (Continued)
●XC9272B Type, with CL discharge function
PARAMETER
SYMBOL
Input Voltage
VIN
CONDITIONS
-
MIN.
TYP.
MAX.
UNITS
CIRCUIT
2.0
-
6.0
V
①
V
②
Resistor connected with LX pin.
Output Voltage
VOUT(E) (*2)
Voltage which LX pin changes “L” to “H” level
E1
while VOUT is decreasing.
VCE=VIN, VOUT=0V. Resistor connected with LX pin.
UVLO Release Voltage
VUVLO(E)
1.65
1.8
1.95
V
②
0.1
0.15
0.23
V
②
VIN=VCE=2.0V, VOUT=VOUT(T)+0.5V (*1), LX=Open.
-
0.5
0.8
μA
③
Voltage which LX pin changes “L” to “H” level
while VIN is increasing.
UVLO Hysteresis
Voltage
Supply Current
VCE=VIN, VOUT=0V. Resistor connected with LX pin.
VHYS(E)
VUVLO(E) - Voltage which LX pin changes “H” to “L”
level while VIN is decreasing.
Iq
Standby Current
ISTB
VIN=5.0V, VCE=VOUT=0V, LX=Open.
-
0.1
1.0
μA
③
LX SW “H” Leak Current
ILEAKH
VIN=5.0V, VCE=VOUT=0V, VLX=0V.
-
0.1
1.0
μA
③
LX SW “L” Leak Current
ILEAKL
VIN=5.0V, VCE=VOUT=0V, VLX=5.0V.
-
0.1
1.0
μA
③
115
180
250
mA
①
-
85
-
%
①
PFM Switching Current
Efficiency (*3)
LX SW “Pch”
ON Resistance (*4)
LX SW “Nch”
ON Resistance
Output Voltage
Temperature
Characteristics
IPFM
EFFI
VIN=VCE=VOUT(T)+2.0V
(*1)
, IOUT=10mA.
VIN=VCE=3.6V,
VOUT(T)=0.7V (*1), IOUT=30mA.
RLXP
VIN=VCE=5.0V, VOUT=0V, ILX=50mA.
-
0.4
0.65
Ω
④
RLXN
VIN=VCE=5.0V.
-
0.4 (*5)
-
Ω
-
-40℃≦Topr≦85℃.
-
±100
-
ppm/℃
②
1.2
-
6.0
V
⑤
GND
-
0.3
V
⑤
ΔVOUT/
(VOUT・ΔTopr)
VOUT=0V. Resistor connected with LX pin.
CE “High” Voltage
VCEH
Voltage which LX pin changes “L” to “H” level while
VCE=0.2→1.5V.
VOUT=0V. Resistor connected with LX pin.
CE “Low” Voltage
VCEL
Voltage which LX pin changes “H” to “L” level while
VCE=1.5→0.2V.
CE “High” Current
ICEH
VIN=VCE=5.0V, VOUT=0V, LX=Open.
-0.1
-
0.1
μA
⑤
CE “Low” Current
ICEL
VIN=5.0V, VCE=VOUT=0V, LX=Open.
-0.1
-
0.1
μA
⑤
0.14
0.3
0.48
V
②
55
80
105
Ω
③
Short Protection
Threshold Voltage
CL Discharge
Resistor connected with LX pin.
VSHORT
Voltage which LX pin changes “H” to “L” level while
VOUT= VOUT(T)+0.1V→0V(*1).
RDCHG
VIN=VOUT=5.0V, VCE=0V, LX=Open.
Unless otherwise stated, VIN=VCE=5.0V
(*1)
VOUT(T)=Nominal Output Voltage
(*2)
VOUT(E)=Effective Output Voltage
The actual output voltage value VOUT(E) is the PFM comparator threshold voltage in the IC.
Therefore, the DC/DC circuit output voltage, including the peripheral components, is boosted by the ripple voltage average value.
Please refer to the characteristic example.
(*3)
EFFI=[{ (Output Voltage)×(Output Current)] / [(Input Voltage)×(Input Current)}]×100
(*4)
LX SW “Pch” ON resistance = (VIN – VLX pin measurement voltage) / 50mA
(*5)
Designed value
6/24
XC9140 (Design Target)
XC9272
Series
■ELECTRICAL CHARACTERISTICS (Continued)
XC9272 series voltage specification chart
SYMBOL
E1
PARAMETER
Output Voltage
UNITS: V
UNITS: V
OUTPUT
VOLTAGE
MIN.
MAX.
0.60
0.58
0.62
0.65
0.63
0.67
0.70
0.68
0.72
0.75
0.73
0.77
0.80
0.78
0.82
0.85
0.83
0.87
0.90
0.88
0.92
0.95
0.93
0.97
7/24
XC9272 Series
■TEST CIRCUITS
< Test Circuit No.2 >
< Test Circuit No.1 >
Wave Form Measure Point
Wave Form Measure Point
IOUT
L
A
CIN
VIN
LX
CE
VOUT
CIN
VIN
LX
CE
VOUT
Rpulldown
CL
GND
V
※ External Components
※ External Components
L
: 10uH
CIN : 10uF (ceramic)
CL : 22uF (ceramic)
CIN : 10uF
Rpulldown : 100Ω
< Test Circuit No.3 >
A
< Test Circuit No.4 >
VIN
LX
CIN
CIN
CE
VOUT
A
A
※ External Components
CIN : 10uF
CIN : 10uF
< Test Circuit No.5 >
Wave Form Measure Point
VIN
LX
ICEH
A
ICEL
※ External Components
CIN : 10uF
Rpulldown : 100Ω
8/24
CE
VOUT
GND
VIN
CE
GND
※ External Components
CIN
GND
V
Rpulldown
LX
VOUT
GND
V
IS
XC9140 (Design Target)
XC9272
Series
■TYPICAL APPLICATION CIRCUIT
【Typical Examples】
MANUFACTURE
PRODUCT NUMBER
VALUE
TDK
VLF302512M-100M
10μH
Coilcraft
LPS3015-103MRB
10μH
Murata
DFE201610E-100M
10μH
CIN
TAIYO YUDEN
LMK107BJ106MA
10μF/10V
CL
TAIYO YUDEN
JMK107BJ226MA
22μF/6.3V
L
* Take capacitance loss, withstand voltage, and other conditions into consideration when selecting components.
* Characteristics are dependent on deviations in the coil inductance value. Test fully using the actual device.
* A value of 10μH is recommended for the coil inductance.
* If a tantalum or electrolytic capacitor is used for the load capacitance CL, ripple voltage will increase, and there is a possibility that operation will
become unstable. Test fully using the actual device.
9/24
XC9272 Series
■OPERATIONAL EXPLANATION
The XC9272 series consists of a reference voltage supply, PFM comparator, Pch driver Tr, Nch synchronous rectification switch
Tr, current sensing circuit, PFM control circuit, CE control circuit, and others. (Refer to the block diagram below.)
PFM Comparator Unit
PFM Comparator Unit
VOUT
VOUT
CFB
CFB
RFB1
Short
protection
RFB2
CL
Discharge
PFM
Comparator
RFB2
CE
CE Controller Logic
PFM
Comparator
+
PFM
Controller
VREF
Synch
Buffer
Driver
PFM
Controller
LX
CE
CE Controller Logic
VREF
Synch
Buffer
Driver
LX
VDD
VDD
VIN
Current
Sense
FB -
FB +
RFB1
Short
protection
Current
Sense
GND
UVLO
VIN start up
Controller
VIN
XC9272A Type
GND
UVLO
VIN start up
Controller
XC9272B Type
An ultra-low quiescent current circuit and synchronous rectification enable a significant reduction of dissipation in the IC, and the
IC operates with high efficiency at both light loads and heavy loads. Current limit PFM is used for the control method, and even
when switching current superposition occurs, increases of output voltage ripple are suppressed, allowing use over a wide voltage
and current range. The IC is compatible with low-capacitance ceramic capacitors, and a small, high-performance step-down DCDC converter can be created.
The actual output voltage VOUT(E) in the electrical characteristics is the threshold voltage of the PFM comparator in the block
diagram. Therefore the average output voltage of the step-down circuit, including peripheral components, depends on the ripple
voltage. Before use, test fully using the actual device
Reference voltage for stabilization of the output voltage of the IC.
(1) The feedback voltage (FB voltage) is the voltage that results from dividing the output voltage with the IC internal dividing
resistors RFB1 and RFB2. The PFM comparator compares this FB voltage to VREF. When the FB voltage is lower than VREF, the PFM
comparator sends a signal to the buffer driver through the PFM control circuit to turn on the Pch driver Tr. When the FB voltage is
higher than VREF, the PFM comparator sends a signal to prevent the Pch driver Tr from turning on.
(2) When the Pch driver Tr is on, the current sense circuit monitors the current that flows through the Pch driver Tr connected to the
Lx pin. When the current reaches the set PFM switching current (IPFM), the current sense circuit sends a signal to the buffer driver
through the PFM control circuit. This signal turns off the Pch driver Tr and turns on the Nch synchronous rectification switch Tr.
(3) The on time of the Nch synchronous rectification switch Tr is dynamically optimized inside the IC. After the off time elapses
and the PFM comparator detects that the VOUT voltage is higher than the set voltage, the PFM comparator sends a signal to the
PFM control circuit that prevents the Pch driver Tr from turning on. However, if the VOUT voltage is lower than the set voltage, the
PFM comparator starts Pch driver Tr on.
By continuously adjusting the interval of the linked operation of (1), (2) and (3) above in response to the load current, the output
voltage is stabilized with high efficiency from light loads to heavy loads.
10/24
XC9140 (Design Target)
XC9272
Series
■OPERATIONAL EXPLANATION (Continued)
The PFM switching current monitors the current that flows through the Pch driver Tr, and is a value that limits the Pch driver Tr current.
The Pch driver Tr remains on until the coil current reaches the PFM switching current (IPFM). An approximate value for this on-time
tON can be calculated using the following equation:
tON = L × IPFM / (VIN – VOUT)
To avoid excessive ripple voltage in the event that the coil current does not reach the PFM switching current within a certain
interval even though the Pch driver Tr has turned on and the FB voltage is above VREF, the Pch driver Tr can be turned off at any
timing using the maximum on-time function of the PFM control circuit. If the Pch driver Tr turns off by the maximum on-time function
instead of the current sense circuit, the Nch synchronous rectification switch Tr will not turn on and the coil current will flow to the
VOUT pin by means of the parasite diode of the Nch synchronous rectification switch Tr.
When the VIN voltage rises, VIN start mode stops the short-circuit protection function during the interval until the FB voltage
approaches VREF. After the VIN voltage rises and the FB voltage approaches VREF by step-down operation, VIN start mode is
released. In order to prevent an excessive rush current while VIN start mode is activated, Nch synchronous rectification switch Tr
will not turn on and the coil current flows to the VOUT pin by means of the parasitic diode of the Nch synchronous rectification Tr.
In VIN start mode as well, the coil current is limited by the PFM switching current.
The short-circuit protection function monitors the VOUT voltage. In the event that the VOUT pin is accidentally shorted to GND or an
excessive load current causes the VOUT voltage to drop below the set short-circuit protection voltage, the short-circuit protection
function activates, and turns off and latches the Pch driver Tr at any selected timing. Once in the latched state, the IC is turned off
and then restarted from the CE pin, or operation is started by re-applying the VIN voltage.
When the VIN pin voltage drops below the UVLO detection voltage, the IC stops switching operation at any selected timing, turns
off the Pch driver Tr and Nch synchronous rectification switch Tr (UVLO mode). When the VIN pin voltage recovers and rises above
the UVLO release voltage, the IC restarts operation.
On the XC9272 series, a CL discharge function is available as an option (XC9272B type). This function enables quick discharging
of the CL load capacitance when “L” voltage is input into the CE pin by the Nch Tr connected between the VOUT-GND pins, or in
UVLO mode. This prevents malfunctioning of the application in the event that a charge remains on CL when the IC is stopped.
The discharge time is determined by CL and the CL discharge resistance RDCHG, including the Nch Tr (refer to the diagram below).
Using this time constant τ= CL×RDCHG, the discharge time of the output voltage is calculated by means of the equation below.
V = VOUT × e - t /τ, or in terms of t, t = τIn(VOUT / V)
V: Output voltage after discharge
VOUT : Set output voltage
t: Discharge time
CL: Value of load capacitance (CL)
RDCHG : Value of CL discharge resistance Varies by power supply voltage.
τ: CL × RDCHG
The CL discharge function is not available on the XC9272A type.
CE / UVLO
Signal
VOUT
R
RDCHG = R + RON
RON
11/24
XC9272 Series
■NOTE ON USE
1. Be careful not to exceed the absolute maximum ratings for externally connected components and this IC.
2. The DC/DC converter characteristics greatly depend not only on the characteristics of this IC but also on those of externally
connected components, so refer to the specifications of each component and be careful when selecting the components. Be
especially careful of the characteristics of the capacitor used for the load capacity CL and use a capacitor with B characteristics
(JIS Standard) or an X7R/X5R (EIA Standard) ceramic capacitor.
3. Use a ground wire of sufficient strength. Ground potential fluctuation caused by the ground current during switching could cause
the IC operation to become unstable, so reinforce the area around the GND pin of the IC in particular.
4. Mount the externally connected components in the vicinity of the IC. Also use short, thick wires to reduce the wire impedance.
5. When the voltage difference between VIN and VOUT is small, switching energy increases and there is a possibility that the ripple
voltage will be too large. Before use, test fully using the actual device.
6. The CE pin does not have an internal pull-up or pull-down, etc. Apply the prescribed voltage to the CE pin.
7. If other than the inductance and capacitance values listed in the “Typical example” are used, excessive ripple voltage or a drop
in efficiency may result.
8. If other than the inductance and capacitance values listed in the “Typical example” are used, a drop of output voltage at load
transient may cause the short-circuit protection function to activate. Before use, test fully using the actual device.
9. At high temperature, excessive ripple voltage may occur and cause a drop in output voltage and efficiency. Before using at high
temperature, test fully using the actual device
10. At light loads or when IC operation is stopped, leakage current from the Pch driver Tr may cause the output voltage to rise.
11. The average output voltage may vary due to the effects of output voltage ripple caused by the load current. Before use, test
fully using the actual device.
12. If VIN voltage is high or the CL capacitance or load current is large, the output voltage rise time will lengthen when the IC is
started, and coil current overlay may occur during the interval until the output voltage reaches the set voltage (refer to the
diagram below).
13. When the IC is started, the short-circuit protection function does not operate during the interval until the VOUT
voltage reaches a value near the set voltage.
14. If the load current is excessively large when the IC is started, it is possible that the VOUT voltage will not rise to the set voltage.
Before use, test fully using the actual device.
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XC9140 (Design Target)
XC9272
Series
■NOTE ON USE (Continued)
15. In actual operation, the maximum on-time depends on the peripheral components, input voltage, and load current. Before use,
test fully using the actual device.
16. When the VIN voltage is turned on and off continuously, excessive rush current may occur while the voltage is on. Before use,
test fully using the actual device.
17. When the VIN voltage is high, the Pch driver may change from on to off before the coil current reaches the PFM switching
current (IPFM), or before the maximum on-time elapses. Before use, test fully using the actual device.
18. For temporary, transitional voltage drop or voltage rising phenomenon, the IC is liable to malfunction should the ratings be
exceeded.
19. Torex places an importance on improving our products and their reliability.
We request that users incorporate fail-safe designs and post-aging protection treatment when using Torex products in their
systems.
13/24
XC9272 Series
■NOTE ON USE (Continued)
●Instructions of pattern layouts
1. To suppress fluctuations in the VIN potential, connect a bypass capacitor (CIN) in the shortest path between the VIN pin and
ground pin.
2. Please mount each external component as close to the IC as possible.
3. Wire external components as close to the IC as possible and use thick, short connecting traces to reduce the circuit impedance.
4. Make sure that the ground traces are as thick as possible, as variations in ground potential caused by high ground currents at
the time of switching may result in instability of the IC.
5. Internal driver transistors bring on heat because of the transistor current and ON resistance of the driver transistors.
●Reference Pattern Layout (USP-6EL)
Top view
●Reference Pattern Layout (SOT-25)
14/24
Bottom view
XC9140 (Design Target)
XC9272
Series
Top view
Bottom view
15/24
XC9272 Series
■TYPICAL PERFORMANCE CHARACTERISTICS
(1) Efficiency vs. Output Current
(2) Output Voltage vs. Output Current
16/24
XC9140 (Design Target)
XC9272
Series
■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(2) Output Voltage vs. Output Current
(3) Ripple Voltage vs. Output Current
17/24
XC9272 Series
■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(4) Output Voltage vs. Ambient Temperature
(5) Supply Current vs. Ambient Temperature
(6) Standby Current vs. Ambient Temperature
18/24
XC9140 (Design Target)
XC9272
Series
■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(7) UVLO Release Voltage vs. Ambient Temperature
(8) PFM Switching Current vs. Ambient Temperature
(9) Maximum Frequency vs. Ambient Temperature
19/24
XC9272 Series
■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(10) Pch Driver ON Resistance vs. Ambient Temperature
(12) Lx SW "H" Leakage Current vs. Ambient Temperature
(14) CE "High" Voltage vs. Ambient Temperature
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(11) Nch Driver ON Resistance vs. Ambient Temperature
(13) Lx SW "L" Leakage Current vs. Ambient Temperature
(15) CE "Low" Voltage vs. Ambient Temperature
XC9140 (Design Target)
XC9272
Series
■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(16) CL Discharge vs. Ambient Temperature
(17) Short Protection Threshold vs. Ambient Temperature
(18) Rising Output Voltage
21/24
XC9272 Series
■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(19) Load Transient Response
22/24
XC9140 (Design Target)
XC9272
Series
■PACKAGING INFORMATION
For the latest package information go to, www.torexsemi.com/technical-support/packages
PACKAGE
OUTLINE / LAND PATTERN
THERMAL CHARACTERISTICS
SOT-25
SOT-25 PKG
Standard Board
SOT-25 Power Dissipation
USP-6EL(DAF)
USP-6EL PKG
Standard Board
USP-6EL Power Dissipation
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XC9272 Series
■MARKING RULE
●SOT-25(Under dot仕様)
dot)
SOT-25(Under
5
4
①
② ③
1
2
④
⑤
3
Magnified
拡大
●USP-6EL
USP-6EL
①
1
④
②
⑤
③
2
3
6
5
4
① represents product series
MARK
PRODUCT SERIES
C
XC9272A/B*****-G
※SOT-25 Under dot
② represents output voltage
MARK
OUTPUT VOLTAGE
PRODUCT SERIES
N
0.6
0.65
XC9272*06***-G
P
0.7
0.75
XC9272*07***-G
R
0.8
0.85
XC9272*08***-G
S
0.9
0.95
XC9272*09***-G
③ represents product type and output voltage type
MARK
PRODUCT TYPE
OUTPUT VOLTAGE TYPE
PRODUCT SERIES
N
Without CL Discharge
Output Voltage {x.x0V} (the 2nd decimal place is “0”)
XC9272A**1**-G
P
Without CL Discharge
Output Voltage {x.x5V} (the 2nd decimal place is “5”)
XC9272A**B**-G
R
With CL Discharge
Output Voltage {x.x0V} (the 2nd decimal place is “0”)
XC9272B**1**-G
S
With CL Discharge
Output Voltage {x.x5V} (the 2nd decimal place is “5”)
XC9272B**B**-G
④⑤ represents production lot number
01~09、0A~0Z、11~9Z、A1~A9、AA~AZ、B1~ZZ
(G, I, J, O, Q, W excluded)
* No character inversion used.
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XC9140 (Design Target)
XC9272
Series
1.
The product and product specifications contained herein are subject to change without notice to
improve performance characteristics. Consult us, or our representatives before use, to confirm that
the information in this datasheet is up to date.
2.
The information in this datasheet is intended to illustrate the operation and characteristics of our
products. We neither make warranties or representations with respect to the accuracy or completeness
of the information contained in this datasheet nor grant any license to any intellectual property rights
of ours or any third party concerning with the information in this datasheet.
3.
Applicable export control laws and regulations should be complied and the procedures required by
such laws and regulations should also be followed, when the product or any information contained in
this datasheet is exported.
4.
The product is neither intended nor warranted for use in equipment of systems which require extremely
high levels of quality and/or reliability and/or a malfunction or failure which may cause loss of human
life, bodily injury, serious property damage including but not limited to devices or equipment used in 1)
nuclear facilities, 2) aerospace industry, 3) medical facilities, 4) automobile industry and other
transportation industry and 5) safety devices and safety equipment to control combustions and
explosions. Do not use the product for the above use unless agreed by us in writing in advance.
5.
Although we make continuous efforts to improve the quality and reliability of our products; nevertheless
Semiconductors are likely to fail with a certain probability. So in order to prevent personal injury and/or
property damage resulting from such failure, customers are required to incorporate adequate safety
measures in their designs, such as system fail safes, redundancy and fire prevention features.
6.
Our products are not designed to be Radiation-resistant.
7.
Please use the product listed in this datasheet within the specified ranges.
8.
We assume no responsibility for damage or loss due to abnormal use.
9.
All rights reserved. No part of this datasheet may be copied or reproduced unless agreed by Torex
Semiconductor Ltd in writing in advance.
TOREX SEMICONDUCTOR LTD.
25/24