XC9128/XC9129 Series
ETR0411-004
1A Driver Transistor Built-In, Step-Up DC/DC Converters
■GENERAL DESCRIPTION
The XC9128/XC9129 series are synchronous step-up DC/DC converters with a 0.2Ω (TYP.) N-channel driver transistor and a
synchronous 0.2Ω (TYP.) P-channel switching transistor built-in. A highly efficient and stable current can be supplied up to
1.0A by reducing ON resistance of the built-in transistors. With a high switching frequency of 1.2MHz, a small inductor is
selectable making the series ideally suited for applications requiring low profile or space saving solutions. With the MODE
pin, the series provides mode selection of PWM control or PFM/PWM automatic switching control. In the PWM/PFM
automatic switching mode, the series switches from PWM to PFM to reduce switching loss when load current is small.
When load current is large, the series switches automatically to the PWM mode so that high efficiency is achievable over a
wide range of load conditions. The series also provides small output ripple from light to large loads by using the built-in
circuit which enables the smooth transition between PWM and PFM. When a voltage higher than the input voltage is
applied to the output during shut-down, the input and the output become isolated making it possible for the IC to work in
parallel with the likes of an AC adaptor.
■APPLICATIONS
■ FEATURES
●Digital audio equipment
High Efficiency, Large Current Step-Up Converter
Output Current
: 150mA＠VOUT=3.3V, VIN=0.9V
500mA＠VOUT=3.3V, VIN=1.8V
Input Voltage Range
: 0.8V~6.0V
Output Voltage Setting
: 1.8V~5.3V (Externally set)
Range
Set up freely with a reference voltage
supply of 0.45V (±0.01V) & external
components
Oscillation Frequency
: 1.2MHz (Fixed oscillation frequency
accuracy ±15%)
Input Current
: 1.0A
Maximum Current Limit
: 1.2A (MIN.), 2.0A (MAX.)
Control
: PWM, PWM/PFM control
externally selectable
High Speed
:100mV @ VOUT=3.3V,
Transient Response
VIN=1.8V, IOUT=10mA→100mA
Protection Circuits
: Thermal shutdown
: Integral latch method (Over current limit)
Soft-Start Time
: 5ms (TYP.) internally set
●Digital cameras, Video equipment
●Computer Mice
●Various multi-function power supplies using alkali cells (1
to 3 cells), nickel hydride batteries, or single lithium cells
Ceramic Capacitor Compatible
Adaptor Enable Function
Packages
: MSOP-10, USP-10B, SOP-8
Flag Output (FO)
: Open-drain output
■TYPICAL PERFORMANCE
CHARACTERISTICS
●Efficiency vs. Output Current
XC9128B45CDx
VOUT=5.0V, fOSC=1.2MHz
L=4.7μH (CDRH4D28C), CIN=10μF, CL=32μF
100
80
Efficiency : EFFI (%) ■TYPICAL APPLICATION CIRCUIT
60
3.7V
VIN=1.8V
40
20
PWM(MODE:H)
PWM/PFM(MODE:L)
0
0.1
1
10
100
Output Current : IOUT (mA)
1000
Output Current: IOUT (mA)
1/14
XC9128/XC9129 Series
■PIN CONFIGURATION
10 VOUT
PGND 1
Lx 2
9 MODE
BAT 3
8 FB
EN 4
7 AGND
FO 5
6 AEN/
MSOP-10
(TOP VIEW)
FO 5
6 AEN/
EN 4
7 AGND
8 FB
BAT 3
9 MODE
Lx 2
10 VOUT
PGND 1
USP-10B
(BOTTOM VIEW)
8 VOUT
PGND 1
7 MODE
Lx 2
6 FB
BAT 3
5 AGND
EN 4
SOP-8
(TOP VIEW)
Under Development
■PIN ASSIGNMENT
PIN NUMBER
MSOP-10* USP-10B *
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
SOP-8 **
1
2
3
4
5
6
7
8
PIN NAME
FUNCTION
PGND
Lx
BAT
EN
FO
AEN/
AGND
FB
MODE
VOUT
Power Ground
Output of Internal Power Switch
Battery Input
Chip Enable
Flag Output
Adaptor Enable
Analog Ground
Output Voltage Monitor
Mode Switch
Output Voltage
* For MSOP-10 and USP-10B packages, please short the GND pins (pins 1 and 7).
*The dissipation pad for the USP-10B package should be solder-plated following the recommended mount pattern and metal masking
so as to enhance mounting strength and heat release. If the pad needs to be connected to other pins, it should be connected to the
Ground pins (pins 1 and 7).
** For SOP-8 package, please short the GND pins (pins 1 and 5).
2/14
XC9128/XC9129
Series
■FUNCTION CHART
1. EN, AEN/ Pin Function
EN PIN
AEN/ PIN
IC OPERATIONAL STATE
SOFT-START FUNCTION
L→H
L
Operation
Available
H
H→L
Operation
Not Available
H
H
Step-Up Operation Shut-Down
-
L
L
Shut-Down
-
L
H
Shut-Down
-
* Do not leave the EN and AEN/ Pins open.
2. MODE Pin Function
MODE PIN
FUNCTION
H
L
PWM Control
PWM/PFM Automatic Switching Control
* Do not leave the MODE Pin open.
■PRODUCT CLASSIFICATION
●Ordering Information
XC9128①②③④⑤⑥・・・・ MSOP-10, USP-10B
XC9129①②③④⑤⑥・・・・ SOP-8 (Under Development)
DESIGNATOR
DESCRIPTION
SYMBOL
①
Transistor Built-In,
Output Voltage Freely Set (FB voltage),
Integral Protection Type
B
: With integral protection
D
: Without integral protection
②③
Reference Voltage
45
④
Oscillation Frequency
C
: 1.2MHz
A
: MSOP-10
⑤
Packages
D
: USP-10B
S
: SOP-8
R
: Embossed tape, standard feed
L
: Embossed tape, reverse feed
⑥
Device Orientation
DESCRIPTION
: Fixed reference voltage 0.45Ｖ
②=4, ③=5
3/14
XC9128/XC9129 Series
■BLOCK DIAGRAM
●XC9128 Series
●XC9129 Series
The AEN/Pin and FO Pin are not connected to the circuit in the block diagram of the XC9129 series.
■ABSOLUTE MAXIMUM RATINGS
Ta=25℃
PARAMETER
SYMBOL
RATINGS
UNITS
VOUT Pin Voltage
AEN/ Pin Voltage
FO Pin Voltage
FO Pin Current
FB Pin Voltage
BAT Pin Voltage
MODE Pin Voltage
EN Pin Voltage
LX Pin Voltage
LX Pin Current
MSOP-10
USP-10B
Power Dissipation
SOP-8
(Under Development)
Operating Temperature Range
Storage Temperature Range
VOUT
VAEN/
VFO
IFO
VFB
VBAT
VMODE
VEN
VLx
ILx
- 0.3～6.5
- 0.3～6.5
- 0.3～6.5
10
- 0.3～6.5
- 0.3～6.5
- 0.3～6.5
- 0.3～6.5
- 0.3～VOUT+0.3
2000
350 (*1)
150
V
V
V
mA
V
V
V
V
V
mA
*1: When implemented on a PCB.
4/14
Pd
mW
300
Topr
Tstg
- 40～+85
- 55～+125
o
o
C
C
XC9128/XC9129
Series
■ELECTRICAL CHARACTERISTICS
Topr=25 oC
XC9128/XC9129 Series
PARAMETER
SYMBOL
Input Voltage
VIN
CONDITIONS
MIN.
TYP.
MAX.
UNITS
CIRCUIT
-
FB Voltage
VFB
VOUT=VIN=3.3V, Vpull=3.3V, VFO=0V
Voltage to start oscillation during
FB=0.46V → 0.44V
Output Voltage Setting Range
VOUTSET
-
Operation Start Voltage
VST1
Connect to external components,
RL =1kΩ
Connect to external components,
RL =33Ω
Voltage to start oscillation during
VIN=0V → 1V
-
-
6.0
V
-
0.44
0.45
0.46
V
④
1.8
-
5.3
V
①
-
-
0.8
V
①
-
-
V
①
-
0.8
-
V
①
0.9
(*1)
Oscillation Start Voltage
VST2
Operation Hold Voltage
VHLD
Connect to external components, RL=1kΩ
-
0.7
-
V
①
Supply Current 1
IDD1
VIN = VOUT =3.3V, FB=VFB×0.9
-
3
6
mA
②
Supply Current 2
IDD2
Input Pin Current
IBAT
VIN = VOUT =3.3V
FB=VFB×1.1 (Oscillation stops),
MODE=0V
VIN =3.3V, VOUT =1.8V, EN=0V
Stand-by Current
ISTB
VIN = VOUT =3.3V, EN=0V
-
2
10
μA
②
Oscillation Frequency
fOSC
VIN = VOUT =3.3V, VFO=0V, FB=VFB×0.9
1.02
1.20
1.38
MHz
④
Maximum Duty Cycle
MAXDTY
VIN = VOUT =3.3V, VFO=0V, FB=VFB×0.9
85
92
96
%
④
Minimum Duty Cycle
MINDTY
VIN = VOUT =3.3V, VFO=0V, FB=VFB×1.1
-
-
0
%
④
-
250
400
mA
①
-
93
-
%
①
-
0.20
0.35 (*1)
Ω
⑤
-
0.20 (*1)
0.35 (*1)
Ω
⑦
-
1
-
μA
⑤
1.2
1.5
2.0
A
①
-
3.5
-
ms
①
1.7
5.3
10.5
ms
④
-
0.02
0.04
ms
④
1.7
5.3
10.5
ms
④
PFM Switching Current
IPFM
Efficiency (*2)
EFFI
LX SW "Pch" ON Resistance
RLxP
LX SW "Nch" ON Resistance
RLxN
LX Leak Current
ILXL
Current Limit (*5)
ILIM
Integral Latch Time (*6)
TLAT
Soft-Start Time 1
TSS1
Soft-Start Time 2
TSS2
Soft-Start Time 3
TSS3
Thermal Shutdown
Temperature
Hysteresis Width
Connect to external components,
MODE=0V, IOUT=10mA
Connect to external components,
IOUT=100mA
VIN=VOUT+50mV,
(*3)
FB=VFB×1.1, MODE=0V
VIN=3.3V, VOUT=3.3V,Lx=50mV,
FB=VFB×0.9 (*4)
VOUT=VLx=VIN=3.3V, EN=0V,
FB=0V, MODE=0V
VOUT>2.5V
Time to stop oscillation during
RL=33Ω → 3.3Ω, VFO=L → H
Time to start oscillation during VEN=0V
→ VIN at VIN = VOUT =3.3V, VFO=0V,
FB=VFB×0.95
VIN = VOUT =3.3V, VFO=0V, FB> VFB×0.95
Time to start oscillation during
VAEN/=VIN→0V.
VIN = VOUT =3.3V, VFO=0V, FB<VFB×0.8
Time to start oscillation during
VAEN/=VIN→0V
30
80
μA
②
-
2
10
μA
③
TTSD
-
-
150
-
o
C
-
THYS
-
20
-
o
C
-
1.3
1.48
1.56
V
⑥
1.3
1.7
2.2
mA
④
-
0
1
μA
④
FO Output Current (*7)
IFO_OUT
VIN =3.3V
Voltage to stop oscillation during
VOUT=1.56V→1.3V
VIN =VOUT=3.3V, VFO=0.25V
FO Leak Current (*7)
IFO_Leak
VIN = VOUT =3.3V, EN=0V ,VFO=1V
Output Voltage Drop
(*6)
Protection
-
LVP
5/14
XC9128/XC9129 Series
■ELECTRICAL CHARACTERISTICS (Continued)
Topr=25 oC
●XC9128/XC9129 Series (Continued)
PARAMETER
SYMBOL
EN "H" Voltage
VENH
CONDITIONS
MIN.
TYP.
MAX.
UNITS
CIRCUIT
0.65
-
-
V
④
VIN =VOUT=3.3V, VFO=0V
Voltage to start oscillation during FB=VFB×0.9,
EN= 0.2V→0.65V
VIN = VOUT =3.3V, VFO=0V
EN "L" Voltage
VENL
Voltage to stop oscillation during FB=VFB×0.9,
EN= 0.65V→0.2V
-
-
0.2
V
④
MODE "H" Voltage
VMODEH
IOUT=10mA, Voltage operates at PWM control
0.65
-
-
V
①
MODE "L" Voltage
VMODEL
IOUT=10mA, Voltage operates at PFM control
-
-
0.2
V
①
AEN/ Voltage (*7)
VAEN/
VIN = VOUT =3.3V, VFO=0V
Voltage to start oscillation during AEN= 0.9V→0.7V
0.7
0.8
0.9
V
④
EN "H" Current
IENH
VOUT=FB=EN=6.0V
-
-
0.1
μA
②
EN "L" Current
IENL
VOUT=FB=6.0V, EN=0V
-0.1
-
-
μA
②
MODE "H" Current
IMODEH
VOUT=FB=MODE=6.0V
-
-
0.1
μA
②
MODE "L" Current
IMODEL
VOUT=FB=6.0V, MODE=0V
-0.1
-
-
μA
②
AEN/ "H" Current (*7)
IAEN/H
VOUT=FB=AEN/=6.0V
-
-
0.1
μA
②
AEN/ "L" Current (*7)
IAEN/L
VOUT=6.0V, EN=0V, AEN/=0V
-0.1
-
-
μA
②
FB "H" Current
IFBH
VOUT=FB=6.0V
-
-
0.1
μA
②
FB "L" Current
IFBL
VOUT=6.0V, FB=0V
-0.1
-
-
μA
②
Conditions: Unless otherwise stated,
operate at VOUT=3.3V, VIN= 1.8V, EN=3.3V, FB=0V, MODE=3.3V, VFO=3.3V, Vpull=3.3V, AEN/=0V
External Components: RFB1=270kΩ, RFB2=43kΩ, CFB=12pF, L=4.7μH (LTF5022 TDK)
CL1=22μF(ceramic), CL2=10μF(ceramic), CIN=10μF(ceramic)
NOTE:
*
1 : Designed value
*
2 : Efficiency ={(output voltage) X (output current)} ÷ {(input voltage) X (input current)} X 100
*
3 : LX SW "P-ch" ON resistance=（VLx-VOUT pin test voltage）÷100mA
*
4 : Testing method of LX SW "N-ch" ON resistance is stated at test circuits.
*
5 : Current flowing through the Nch driver transistor is limited.
*
6 : The XC9128D series does not have integral protection.
*
7 : The XC9129 series does not have FO or AEN/ pins.
6/14
This is only available with the XC9128B series.
These are only available with the XC9128 series.
XC9128/XC9129
Series
■TYPICAL APPLICATION CIRCUIT
<Output Voltage Setting>
Output voltage can be set by adding external split resistors. Output voltage is determined by the following equation,
based on the values of RFB1 and RFB2. The sum of RFB1 and RFB2 should normally be 500kΩ or less.
VOUT=0.45 × (RFB1 + RFB2) / RFB2
The value of CFB, speed-up capacitor for phase compensation, should be fZFB = 1 / (2 x π x CFB1 x RFB1) which is in
the range of 10 kHz to 50 kHz. Adjustments are depending on application, inductance (L), load capacitance (CL) and
dropout voltage.
[Example of calculation]
When RFB1=270kΩ, RFB2=43kΩ,
VOUT1 = 0.45 × (270k+43k ) / 43k = 3.276V
[Typical example]
VOUT (V)
RFB1 (kΩ)
RFB2 (kΩ)
CFB (pF)
1.8
2.5
3.3
5.0
300
270
270
180
100
59
43
17.8
10
12
12
15
[External Components]
1.2MHz:
L : 4.7μH (CDRH4D28C SUMIDA)
CL1: 22μF (ceramic)
CL2: 10μF (ceramic)
CIN: 10μF (ceramic)
* For CL, use output capacitors of 30μF or more. (Ceramic capacitor compatible)
* If using Tantalum or Electrolytic capacitors please be aware that ripple voltage will be higher due to the larger
ESR (Equivalent Series Resistance) values of those types of capacitors. Please also note that the IC’s
operation may become unstable with such capacitors so we recommend that you fully check actual
performance.
7/14
XC9128/XC9129 Series
■OPERATIONAL EXPLANATION
The XC9128/XC9129 series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM comparator,
phase compensation circuit, N-channel driver transistor, P-channel synchronous rectification switching transistor and current
limiter circuit. The series compares, using the error amplifier, the internal reference voltage to the FB pin with the voltage
fedback via resistors RFB1 and RFB2. Phase compensation is performed on the resulting error amplifier output, to input a
signal to the PWM comparator to determine the turn-on time of the N-ch driver transistor during PWM operation. The PWM
comparator compares, in terms of voltage level, the signal from the error amplifier with the ramp wave from the ramp wave
circuit, and delivers the resulting output to the buffer driver circuit to cause the Lx pin to output a switching duty cycle. This
process is continuously performed to ensure stable output voltage. The current feedback circuit monitors the N-channel
driver transistor’s turn-on current for each switching operation, and modulates the error amplifier output signal to provide
multiple feedback signals. This enables a stable feedback loop even when a low ESR capacitor, such as a ceramic
capacitor, is used, ensuring stable output voltage.
<Reference Voltage Source>
The source provides the reference voltage to ensure stable output of the DC/DC converter.
<Ramp Wave Circuit>
The ramp wave circuit determines switching frequency. The frequency is fixed internally at 1.2MHz. The Clock generated
is used to produce ramp waveforms needed for PWM operation, and to synchronize all the internal circuits.
<Error Amplifier>
The error amplifier is designed to monitor output voltage. The amplifier compares the reference voltage with the feedback
voltage divided by the internal resistors (RFB1 and RFB2). When the FB pin is lower than the reference voltage, output
voltage of the error amplifier increases. The gain and frequency characteristics of the error amplifier are optimized
internally.
< Maximum Current Limit>
The current limiter circuit monitors the maximum current flowing through the N-ch driver transistor connected to the Lx pin,
and features a combination of the current limit and latch function.
1 When the driver current is greater than a specific level (equivalent to peak coil current), the maximum current limit
function starts to operate and the pulses from the Lx pin turn off the N-ch driver transistor at any given time.
2When the driver transistor is turned off, the limiter circuit is then released from the maximum current limit detection state.
3At the next pulse, the driver transistor is turned on. However, the transistor is immediately turned off in the case of an
over current state.
4 When the over current state is eliminated, the IC resumes its normal operation.
The XC9128B/XC9129B series waits for the over current state to end by repeating the steps 1 through 3. If an over current
state continues for several ms and the above three steps are repeatedly performed, the IC performs the function of latching the
OFF state of the Nch driver transistor, and goes into operation suspension mode. After being put into suspension mode, the IC
can resume operation by turning itself off once and then re-starting via the EN pin, or by restoring power to the V IN pin.
The XC9128D/XC9129D series does not have this latch function, so operation steps 1 through 3 repeat until the over current
state ends.
Integral latch time may be released from a over current detection state because of the noise. Depending on the state of a
substrate, it may result in the case where the latch time may become longer or the operation may not be latched. Please locate
an input capacitor as close as possible.
Limit<# ms
8/14
Limit<# ms
XC9128/XC9129
Series
■OPERATIONAL EXPLANATION (Continued)
<Thermal Shutdown>
For protection against heat damage, the thermal shutdown function monitors chip temperature. When the chip’s
temperature reaches 150OC (TYP.), the thermal shutdown circuit starts operating and the driver transistor will be turned off.
At the same time, the output voltage decreases. When the temperature drops to 130OC (TYP.) after shutting off the current
flow, the IC performs the soft start function to initiate output startup operation.
<MODE>
The MODE pin operates in PWM mode by applying a high level voltage and in PFM/PWM automatic switching mode by
applying a low level voltage.
<Shut-Down>
The IC enters chip disable state by applying low level voltage to the EN pin. At this time, the P-ch synchronous switching
transistor turns on when VIN>VOUT and vise versa the transistor turns off when VIN<VOUT.
<Adaptor Enable>
While using step-up DC/DC converters in parallel with an added power source such as AC adaptors, the circuit needs the
step-up DC/DC converter to be transient-efficient for sustaining output voltage in case the added power source runs down.
The AEN/ pin voltage determines whether the added power source is supplied or not so that high-speed following operation is
possible. The IC starts operating although the driver transistor is off when a high level voltage is applied to the AEN/ pin after a
high level voltage is also applied to the EN pin. If the AEN/ pin voltage changes from high level to low level while the EN pin
sustains a high level voltage, the step-up operation starts with high-speed following mode (without soft-start).
<Error Flag >
The FO pin becomes high impedance during over current state, over temperature state, soft-start period, and shut-down period.
■NOTE ON USE
1. Please do not exceed the stated absolute maximum ratings values.
2. The DC/DC converter / controller IC's performance is greatly influenced by not only the ICs' characteristics, but also by
those of the external components. Care must be taken when selecting the external components.
3. Make sure that the PCB GND 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.
4. Please mount each external component as close to the IC as possible and use thick, short traces to reduce the circuit
impedance.
5. When the device is used in high step-up ratio, the current limit function may not work during excessive load current. In this
case, the maximum duty cycle limits maximum current.
6. When the adaptor enable function is used in the below circuit, please use a diode with low reverse bias current. The sum of
RAEN1’s and RAEN2’s resistance should be set to manage the reverse bias current.
9/14
XC9128/XC9129 Series
■NOTE ON USE (Continued)
7. P-ch synchronous switching transistor operation
The parasitic diode of the P-ch synchronous transistor is placed between Lx (anode) and VOUT (cathode), so that the
power line can not be turned off from Lx to VOUT. On the other hand, the power line switch from VOUT to Lx is shown in the
table below.
EN Pin
AEN/Pin
P-ch Synchronous Switch Transistor Operation
H
H
L
L
H
L
H
L
OFF
Switching
OFF
Undefined
With the XC9128B/XC9129B series, when step-up operation stops as a result of the latch condition working when the
maximum current limit level is reached, the synchronous P-ch transistor will remain ON.
With the XC9128B/XC9129B series, when step-up operation stops as a result of the latch condition working when the low
output voltage protection level is reached, the synchronous P-ch transistor will remain ON.
8. The maximum current limiter controls the limit of the N-ch driver transistor by monitoring current flow. This function does
not limit the current flow of the P-ch synchronous transistor.
9. The integral latch time of the XC9128B/XC9129B series could be released from the maximum current detection state as a
result of board mounting conditions. This may extend integral latch time or the level required for latch operation to
function may not be reached. Please connect the output capacitor as close to the IC as possible.
10. When used in small step-up ratios, the device may skip pulses during PWM control mode.
10/14
XC9128/XC9129
Series
■TEST CIRCUITS
< Circuit No.1 >
Wave Form Measure Point
L
Lx
VOUT
BAT
MODE
A
CFB
RFB1
※ External Components
A
EN
CIN
VIN
V
CL1
FB
CL2
VEN
10kΩ
FO
AEN/
PGND
AGND
RL V
VMODE
V
VAEN/
RFB2
L : 4.7uH(LTF5022T-4R7N2R0 : TDK)
CIN : 10uF (ceramic)
CL1 : 22uF (ceramic)
CL2 : 10uF (ceramic)
VFO
Wave Form Measure Point
< Circuit No.2 >
< Circuit No.3 >
A
A
CIN
Lx
VOUT
BAT
MODE
A
EN
FB
A
FO
AEN/
A
VAEN/
PGND
AGND
A
VMODE
CIN
VFB
VIN
VEN
VOUT
BAT
MODE
EN
FB
FO
AEN/
PGND
AGND
VOUT
VIN
VMODE
VFB
VEN
※ External Components
CIN
Lx
※ External Components
: 1uF (ceramic)
CIN
: 1uF (ceramic)
<Circuit No.5 >
< Circuit No.4 >
Wave Form Measure Point
Rpull
Lx
VOUT
BAT
MODE
Lx
VOUT
BAT
MODE
Vpull
A
A
VIN
CIN
EN
FB
FO
AEN/
VMODE
CIN
A
VFO
FO
AEN/
PGND
AGND
COUT
VAEN/
VOUT
FB
VIN
VAEN
PGND
FB
VLx
VFB
VEN
EN
AGND
※ External Components
※ External Components
CIN : 1uF (ceramic)
Rpull : 300Ω
CIN : 1uF (ceramic)
COUT: 1uF (ceramic)
<Circuit No.6 >
Wave Form Measure Point
Rpull
Lx
VOUT
BAT
MODE
Vpull
A
VIN
EN
CIN
VＯＵＴ
FB
VMODE
VEN
A
VFO
FO
V
AEN/
VFB
PGND
AGND
※ External Components
CIN : 1uF (ceramic)
Rpull : 300Ω
11/14
XC9128/XC9129 Series
■TEST CIRCUITS (Continued)
Measurement method for ON resistance of the Lx switch
Using the layout of circuit No.7 above, set the LX pin voltage to 50mV by adjusting the Vpull voltage whilst the N-ch driver
transistor is turned on. Then, measure the voltage difference between both ends of Rpull. ON Resistance is calculated by using
the following formula:
RLXN=0.05 ÷ ((V1 – 0.05) ÷ 0.5)
where V1 is a voltage between SBD and Rpull, measured by an oscilloscope.
12/14
XC9128/XC9129
Series
■PACKAGING INFORMATION
●USP-10B
0. 4 ± 0. 0 3
1. 6 ± 0. 1
0. 2 5 ± 0. 1
MAX0 . 6
2. 6±0. 15
●MSOP-10
●SOP-8
(unit : mm)
+0.05
4.2±0.4
+0.5
5.0 -0.2
0～
10 °
1.5±0.1
0～0.25
+0.4
6.1 -0.3
0.25～0.9
0.2 -0.1
1.27±0.03
0.4±0.1
13/14
XC9128/XC9129 Series
1. The products 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. We assume no responsibility for any infringement of patents, patent rights, or other
rights arising from the use of any information and circuitry in this datasheet.
3. Please ensure suitable shipping controls (including fail-safe designs and aging
protection) are in force for equipment employing products listed in this datasheet.
4. The products in this datasheet are not developed, designed, or approved for use with
such equipment whose failure of malfunction can be reasonably expected to directly
endanger the life of, or cause significant injury to, the user.
(e.g. Atomic energy; aerospace; transport; combustion and associated safety
equipment thereof.)
5. Please use the products listed in this datasheet within the specified ranges.
Should you wish to use the products under conditions exceeding the specifications,
please consult us or our representatives.
6. We assume no responsibility for damage or loss due to abnormal use.
7. All rights reserved. No part of this datasheet may be copied or reproduced without the
prior permission of TOREX SEMICONDUCTOR LTD.
14/14