Datasheet
2.7 V to 5.5 V Input, 600 mA
Single Synchronous Buck DC/DC Converter
for Automotive
BD9S000NUX-C
General Description
Key Specifications
BD9S000NUX-C is a synchronous buck DC/DC
Converter with built-in low On Resistance power
MOSFETs. It is capable of providing current up to 600
mA. Small inductor is applicable due to high switching
frequency of 2.2 MHz. It is a current mode control
DC/DC Converter and features high-speed transient
response. It has a built-in phase compensation circuit.
Applications can be created with a few external
components.
Package
VSON008X2020
Features
Input Voltage:
2.7 V to 5.5 V
Output Voltage Setting:
0.8 V to VIN
Output Current:
600 mA(Max)
Switching Frequency:
2.2 MHz(Typ)
High Side FET ON Resistance:
270 mΩ(Typ)
Low Side FET ON Resistance:
180 mΩ(Typ)
Shutdown Circuit Current:
0 μA(Typ)
Operating Temperature:
-40 °C to +125 °C
W(Typ) x D(Typ) x H(Max)
2.00 mm x 2.00 mm x 0.60 mm
AEC-Q100 Qualified(Note 1)
Single Synchronous Buck DC/DC Converter
Adjustable Soft Start Function
Output Discharge Function
100 % ON Duty Cycle
Power Good Output
Input Under Voltage Lockout Protection (UVLO)
Short Circuit Protection (SCP)
Output Over Voltage Protection (OVP)
Over Current Protection (OCP)
Thermal Shutdown Protection (TSD)
(Note 1) Grade 1
VSON008X2020
Applications
Automotive Equipment
Other Electronic Equipment
Typical Application Circuit
VIN
VIN
PGD
EN
SW
CIN1
VEN
VOUT
L1
SS
COUT1
R1
GND
FB
R2
Figure 1. Application Circuit
〇Product structure : Silicon monolithic integrated circuit
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Pin Configuration
SW
1
8
GND
SW
2
7
VIN
EXP-PAD
SS
3
6
EN
FB
4
5
PGD
(TOP VIEW)
Pin Descriptions
Pin No.
Pin Name
Function
1, 2
SW
Switch pin. These pins are connected to the drain of the High Side FET and the Low Side FET.
3
SS
Pin for setting the soft start time. The rise time of the output voltage can be specified by
connecting a capacitor to this pin. See page 17 on calculate the capacitance.
4
FB
VOUT feedback pin. An inverting input node for the error amplifier. Connect output voltage divider
to this pin to set the output voltage. See page 15 on how to compute for the resistor values.
5
PGD
Power Good pin, an open drain output. Use of pull up resistor is needed. See page 11 on setting
the resistance.
6
EN
Pin for controlling the device. Turning this pin signal Low forces the device to enter the
shutdown mode. Turning this pin signal High makes the device to start up.
7
VIN
Power supply pin. Connecting a 10 µF(Typ) ceramic capacitor is recommended. The detail of a
selection is described in page 16.
8
GND
Ground pin.
-
EXP-PAD
A backside heat dissipation pad. Connecting to the internal PCB ground plane by using via
provides excellent heat dissipation characteristics.
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Block Diagram
EN
6
VREF
3
Soft
Start
SS
VIN
Slope
Error
Amplifier
7
PWM
Comparator
FB
R
4
S
OCP
Q
Driver
Logic
SW
1
VOUT
OSC
VIN
2
UVLO
RDIS
SCP
OVP
GND
Power
Good
8
TSD
5
PGD
Figure 2. Block Diagram
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Description of Blocks
1. VREF
The VREF block generates the internal reference voltage.
2. UVLO (Under Voltage Lockout)
The UVLO block is for under voltage lockout protection. It will shutdown the device when the VIN falls to 2.45 V(Typ) or
lower. The threshold voltage has a hysteresis of 100 mV(Typ).
3. SCP (Short Circuit Protection)
This is the short circuit protection circuit. After soft start is judged to be completed, if the FB pin voltage falls to 0.56 V(Typ)
or less and remain in that state for 1 ms(Typ), output MOSFET will turn OFF for 14 ms(Typ) and then restart the operation.
4. OVP (Over Voltage Protection)
This is the output over voltage protection circuit. When the FB pin voltage becomes 0.92 V(Typ) or more, it turns the output
MOSFET OFF. After output voltage falls 0.88 V(Typ) or less, the output MOSFET returns to normal operation.
5. TSD (Thermal Shutdown)
This is the thermal shutdown circuit. It will shutdown the device when the junction temperature (Tj) reaches to 175 °C(Typ)
or more. When the Tj falls below the TSD threshold, the circuits are automatically restored to normal operation with
hysteresis of 25 °C(Typ).
6. OCP (Over Current Protection)
The Over Current Protection function operates by limiting the current that flows through High Side FET at each cycle of
the switching frequency.
7. Soft Start
The Soft Start circuit slows down the rise of output voltage during startup, which allows the prevention of output voltage
overshoot. The soft start time of the output voltage can be specified by connecting a capacitor to the SS pin. See page 17
on calculate the capacitance. A built-in soft start function is provided and a soft start is initiated in 1 ms(Typ) when the SS
pin is open.
8. Error Amplifier
The Error Amplifier block is an error amplifier and its inputs are the reference voltage 0.8 V(Typ) and the FB pin voltage.
9. PWM Comparator
The PWM Comparator block compares the output voltage of the Error Amplifier and the Slope signal to determine the
switching duty.
10. OSC (Oscillator)
This block generates the oscillating frequency.
11. Driver Logic
This block controls switching operation and various protection functions.
12. Power Good
When the FB pin voltage reaches 0.8 V(Typ) within ±10 %, the built-in Nch MOSFET turns OFF and the PGD output turns
high. In addition, the PGD output turns low when the FB pin voltage reaches outside ±15 % of 0.8 V(Typ).
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Absolute Maximum Ratings
Parameter
Symbol
Rating
Unit
VIN
-0.3 to +7
V
EN Voltage
VEN
-0.3 to VIN
V
PGD Voltage
VPGD
-0.3 to +7
V
VFB, VSS
-0.3 to VIN
V
Tjmax
150
°C
Tstg
-55 to +150
°C
Input Voltage
FB, SS Voltage
Maximum Junction Temperature
Storage Temperature Range
Caution 1: Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit
between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is
operated over the absolute maximum ratings.
Caution 2: Should by any chance the maximum junction temperature rating be exceeded the rise in temperature of the chip may result in deterioration of the
properties of the chip. In case of exceeding this absolute maximum rating, design a PCB boards with thermal resistance taken into consideration by
increasing board size and copper area so as not to exceed the maximum junction temperature rating.
Thermal Resistance(Note 1)
Parameter
Symbol
Thermal Resistance (Typ)
Unit
1s(Note 3)
2s2p(Note 4)
θJA
309.5
77.1
°C/W
ΨJT
53
12
°C/W
VSON008X2020
Junction to Ambient
Junction to Top Characterization
Parameter(Note 2)
(Note 1) Based on JESD51-2A(Still-Air).
(Note 2) The thermal characterization parameter to report the difference between junction temperature and the temperature at the top center of the outside
surface of the component package.
(Note 3) Using a PCB board based on JESD51-3.
(Note 4) Using a PCB board based on JESD51-5, 7.
Layer Number of
Measurement Board
Single
Material
Board Size
FR-4
114.3 mm x 76.2 mm x 1.57 mmt
Top
Copper Pattern
Thickness
Footprints and Traces
70 μm
Layer Number of
Measurement Board
4 Layers
Material
Board Size
FR-4
114.3 mm x 76.2 mm x 1.6 mmt
Top
Thermal Via(Note 5)
Pitch
Diameter
1.20 mm
Φ0.30 mm
2 Internal Layers
Bottom
Copper Pattern
Thickness
Copper Pattern
Thickness
Copper Pattern
Thickness
Footprints and Traces
70 μm
74.2 mm x 74.2 mm
35 μm
74.2 mm x 74.2 mm
70 μm
(Note 5) This thermal via connects with the copper pattern of all layers.
Recommended Operating Conditions
Parameter
Symbol
Min
Max
Unit
VIN
2.7
5.5
V
Operating Temperature
Ta
-40
+125
°C
Output Current
IOUT
-
600
mA
Output Voltage Setting
VOUT
0.8(Note 1)
VIN
V
SW Minimum ON Time
tON_MIN
-
80
ns
Input Voltage
(Note 1) Although the output voltage is configurable at 0.8 V and higher, it may be limited by the SW min ON pulse width. For the configurable range,
please refer to the Output Voltage Setting on page 15 in Selection of Components Externally Connected.
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Electrical Characteristics (Unless otherwise specified Ta=Tj=-40 °C to +125 °C, VIN=5 V, VEN=5 V)
Parameter
Symbol
Min
Limit
Typ
Max
Unit
Conditions
VIN
Shutdown Circuit Current
ISDN
-
0
10
µA
Circuit Current
ICC
200
350
500
µA
VUVLO1
VUVLO2
VUVLO-HYS
2.30
2.40
50
2.45
2.55
100
2.60
2.70
125
V
V
mV
VENH
VENL
IEN
1.0
GND
2
5
VIN
0.4
8
V
V
µA
VEN=5 V, Ta=25 °C
FB Pin Voltage
FB Input Current
Soft Start
VFB
IFB
0.788
-
0.8
0
0.812
0.2
V
µA
VFB=0.8 V, Ta=25 °C
0.5
1.0
2.0
ms
Soft Start Time
tSS
0.6
1.2
2.4
ms
ISS
-1.4
-1.0
-0.6
µA
fSW
2.0
2.2
2.4
MHz
VFB
x 0.80
VFB
x 0.85
VFB
x 1.10
VFB
x 1.05
30
0.03
VFB
x 0.85
VFB
x 0.90
VFB
x 1.15
VFB
x 1.10
0
60
0.06
VFB
x 0.90
VFB
x 0.95
VFB
x 1.20
VFB
x 1.15
2
120
0.12
120
150
80
100
270
330
180
210
UVLO Detection Voltage
UVLO Release Voltage
UVLO Hysteresis Voltage
VEN=0 V, Ta=25 °C
IOUT=0 mA
Non-switching, Ta=25 °C
VIN Falling
VIN Rising
ENABLE
EN Threshold Voltage High
EN Threshold Voltage Low
EN Input Current
Reference Voltage
SS Charge Current
VIN=5 V,
The SS Pin OPEN
VIN=3.3 V,
The SS Pin OPEN
Switching Frequency
Switching Frequency
Power Good
PGD Falling (Fault) Voltage
VPGDTH_FF
PGD Rising (Good) Voltage
VPGDTH_RG
PGD Rising (Fault) Voltage
VPGDTH_RF
PGD Falling (Good) Voltage
VPGDTH_FG
PGD Output Leakage Current
PGD FET ON Resistance
PGD Output Low Level Voltage
ILEAKPGD
RPGD
VPGDL
V
VFB Falling
V
VFB Rising
V
VFB Rising
V
VFB Falling
µA
Ω
V
VPGD=5 V, Ta=25 °C
470
550
300
350
mΩ
mΩ
mΩ
mΩ
VIN=5 V
VIN=3.3 V
VIN=5 V
VIN=3.3 V
VIN=5.5 V, VSW=0 V,
Ta=25 °C
VIN=5.5 V, VSW=5.5 V,
Ta=25 °C
IPGD=1 mA
Switch MOSFET
High Side FET ON Resistance
RONH
Low Side FET ON Resistance
RONL
High Side FET Leakage Current
ILEAKSWH
-
0
5
μA
Low Side FET Leakage Current
ILEAKSWL
-
0
5
μA
IOCP
0.8
1.2
1.7
A
RDIS
450
650
850
Ω
VSCP
0.48
0.56
0.64
V
VOVP
0.88
0.92
0.96
V
SW Current of Over Current
Protection(Note 1)
SW Discharge Resistance
SCP, OVP
Short Circuit Protection Detection
Voltage
Output Over Voltage Protection
Detection Voltage
(Note 1) This is design value. Not production tested.
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Typical Performance Curves
Unless otherwise specified VIN = VEN
10
500
VEN = 0 V
450
8
7
Circuit Current : ICC[µA]
Shutdown Circuit Current : ISDN[µA]
9
6
5
4
VIN = 5.0 V
VIN = 3.3 V
3
2
VIN = 5.0 V
400
350
300
250
VIN = 3.3 V
1
0
-50
-25
0
25
50
75
100
200
125
-50
-25
0
25
75
100
125
Temperature[°C]
Temperature[°C]
Figure 3. Shutdown Circuit Current vs Temperature
Figure 4. Circuit Current vs Temperature
0.812
2.40
VIN = 3.3 V
2.35
0.808
2.30
FB Pin Voltage : VFB[V]
Switching Frequency : fSW [MHz]
50
2.25
2.20
2.15
VIN = 5.0 V
2.10
VIN = 5.0 V
0.804
0.800
0.796
VIN = 3.3 V
0.792
2.05
0.788
2.00
-50
-25
0
25
50
75
100
125
-25
0
25
50
75
100
125
Temperature[°C]
Temperature[°C]
Figure 5. Switching Frequency vs Temperature
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Figure 6. FB Pin Voltage vs Temperature
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Typical Performance Curves – continued
-0.60
2.0
CSS = OPEN
1.8
-0.70
SS Charge Current : ISS[µA]
Soft Start Time : tSS[ms]
1.6
VIN = 3.3 V
1.4
1.2
1.0
0.8
VIN = 5.0 V
0.6
0.4
VIN = 3.3 V
-0.90
-1.00
-1.10
VIN = 5.0 V
-1.20
-1.30
0.2
0.0
-1.40
-50
-25
0
25
50
75
100
125
-50
-25
0
25
50
75
100
125
Temperature[°C]
Temperature[°C]
Figure 7. Soft Start Time vs Temperature
Figure 8. SS Charge Current vs Temperature
550
350
Low Side FET ON Resistance : RONL[mΩ]
High Side FET ON Resistance : RONH[mΩ]
-0.80
500
450
VIN = 3.3 V
400
350
300
250
VIN = 5.0 V
200
150
320
VIN = 3.3 V
290
260
230
200
170
VIN = 5.0 V
140
110
80
100
-50
-25
0
25
50
75
100
-50
125
0
25
50
75
100
125
Temperature[°C]
Temperature[°C]
Figure 9. High Side FET ON Resistance vs Temperature
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Figure 10. Low Side FET ON Resistance vs Temperature
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Typical Performance Curves – continued
120
0.96
VIN = 5.0 V
VIN = 5.0 V
PGD FET ON Resistance : RPGD[Ω]
PGD Threshold Voltage : VPGD[V]
0.92
0.88
0.84
Falling Good
Rising Fault
0.80
Rising Good
0.76
Falling Fault
0.72
110
100
90
80
70
60
50
40
0.68
30
0.64
-50
-25
0
25
50
75
100
-50
125
-25
0
25
50
75
100
125
Temperature[°C]
Temperature[°C]
Figure 11. PGD Threshold Voltage vs Temperature
Figure 12. PGD FET ON Resistance vs Temperature
1.0
2.70
VIN = 5.0 V
EN Threshold Voltage : VEN[V]
UVLO Voltage : VUVLO[V]
2.65
Release
2.60
2.55
2.50
2.45
2.40
Detection
2.35
2.30
0.9
Rising
0.8
0.7
0.6
Falling
0.5
0.4
-50
-25
0
25
50
75
Temperature[°C]
100
125
Figure 13. UVLO Voltage vs Temperature
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-50
-25
0
25
50
75
Temperature[°C]
100
125
Figure 14. EN Threshold Voltage vs Temperature
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Typical Performance Curves – continued
10
SW Current of Over Current Protection : IOCP[A]
1.7
9
EN Input Current : IEN[µA]
8
7
6
VEN = 5.0 V
5
4
3
2
VEN = 3.3 V
1
0
-50
-25
0
25
50
75
100
125
VIN = 5.0 V
1.6
1.5
1.4
1.3
1.2
1.1
1
0.9
0.8
-50
-25
0
25
Temperature[°C]
Output Over Voltage Protection Detection Voltage : VOVP[V]
Short Circuit Protection Detection Voltage : VSCP[V]
VIN = 5.0 V
0.62
Release
0.60
0.58
0.56
Detection
0.52
0.50
0.48
-25
0
25
50
75
100
125
Temperature[°C]
Figure 17. Short Circuit Protection Detection Voltage
vs Temperature
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100
125
Figure 16 SW Current of Over Current Protection
vs Temperature
0.64
-50
75
Temperature[°C]
Figure 15. EN Input Current vs Temperature
0.54
50
0.96
VIN = 5.0 V
0.95
0.94
0.93
0.92
0.91
0.90
0.89
0.88
-50
-25
0
25
50
75
100
125
Temperature[°C]
Figure 18. Output Over Voltage Protection Detection Voltage
vs Temperature
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Function Explanations
1.
Enable Control
The device shutdown can be controlled by the voltage applied to the EN pin. When VEN becomes 1.0 V or more, the
internal circuit is activated and the device starts up with soft start. When VEN becomes 0.4 V or less, the device will be
shutdown.
VIN
0
t
VEN
VENH
VENL
0
t
VOUT
VOUT × 0.90 (Typ)
0
t
tSS
t_wait
200 µs(Typ)
Figure 19. Enable ON/OFF Timing Chart
2.
Power Good Function
When the FB pin voltage reaches 0.8 V(Typ) within ±10%, the PGD pin open drain MOSFET turns OFF and the output
turns high. In addition, when the FB pin voltage reaches outside ±15 % of 0.8 V(Typ), the PGD pin open drain
MOSFET turns ON and the PGD pin is pulled down with impedance of 60 Ω(Typ). It is recommended to use a pull-up
resistor of 2 kΩ to 100 kΩ for the power source
+15 %(Typ)
+10 %(Typ)
VOUT
-10 %(Typ)
-15 %(Typ)
(Typ)
PGD
Figure 20. Power Good Timing Chart
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Function Explanations – continued
3.
Output Discharge
When even one of the following conditions is satisfied, output is discharged with 650 Ω(Typ) resistance through SW
pin.
• VEN becomes 0.4 V or less
• VIN becomes 2.45 V(Typ) or less(UVLO)
• VFB becomes 0.56 V(Typ) or less and remains there for 1ms(Typ)(SCP)
• VFB becomes 0.92 V(Typ) or more(OVP)
• Tj becomes 175 °C (Typ) or more(TSD)
When all of the above conditions are released, output discharge is stopped.
4.
100 % ON Duty Cycle
When the input voltage comes close to the setting output voltage, the High Side FET is turned on 100 % for one or
more cycle in order to maintain the output voltage. With further decreasing the input voltage, the High Side FET is
turned on completely.
The minimum input voltage to maintain the output voltage can be represented by following equation.
𝑉𝐼𝑁(𝑀𝑖𝑛) = 𝑉𝑂𝑈𝑇 + 𝐼𝑂𝑈𝑇(𝑀𝑎𝑥) × (𝑅𝑂𝑁𝐻(𝑀𝑎𝑥) + 𝑅𝐿(𝑀𝑎𝑥) ) [V]
where
𝑉𝑂𝑈𝑇
𝐼𝑂𝑈𝑇(𝑀𝑎𝑥)
𝑅𝑂𝑁𝐻(𝑀𝑎𝑥)
𝑅𝐿(𝑀𝑎𝑥)
is the output voltage
is the maximum output current
is the High Side FET ON Resistance(Refer to page 6)
is the DC resistance of the inductor
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Protection
Short Circuit Protection (SCP)
The Short Circuit Protection block compares the FB pin voltage with the internal reference voltage VREF. When the
FB pin voltage has fallen to 0.56 V(Typ) or less and remained there for 1 ms(Typ), SCP stops the operation for 14
ms(Typ) and subsequently initiates a restart. This protection circuit is effective in preventing damage due to sudden
and unexpected incidents. However, the device should not be used in applications characterized by continuous
operation of the protection circuit (e.g. when a load that significantly exceeds the output current capability of the chip is
connected).
1.
The EN Pin
Short Circuit
Protection
The FB Pin
≤0.56 V(Typ)
1.0 V or higher
ON
Enabled
≥0.60 V(Typ)
0.4 V or lower
Short Circuit
Protection Operation
OFF
Disabled
-
OFF
tSS
VOUT
1 ms (Typ)
1 ms (Typ)
0.8 V
FB
VSCP : 0.56 V(Typ)
SCP OFF : 0.60 V(Typ)
SW
LOW
IOCP
Inductor Current
(Output Load
Current)
Internal
HICCUP
Delay Signal
14 ms (Typ)
SCP Reset
Figure 21. Short Circuit Protection (SCP) Timing Chart
2.
Over Current Protection (OCP)
The Over Current Protection function operates by limiting the current that flows through High Side FET at each cycle
of the switching frequency. This protection circuit is effective in preventing damage due to sudden and unexpected
incidents. However, the device should not be used in applications characterized by continuous operation of the
protection circuit (e.g. when a load that significantly exceeds the output current capability of the chip is connected).
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BD9S000NUX-C
Protection – continued
Under Voltage Lockout Protection (UVLO)
It will shutdown the device when the VIN pin falls to 2.45 V(Typ) or lower.
The threshold voltage has a hysteresis of 100 mV(Typ).
3.
VIN
VUVLO-HYS
VUVLO2
VUVLO1
0V
t_wait
200 µs(Typ)
VOUT
tSS
FB
SW
Normal operation
UVLO
Normal operation
Figure 22. UVLO Timing Chart
4.
Thermal Shutdown
This is the thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always be within
the IC’s maximum junction temperature rating. However, if the rating is exceeded for a continued period, the junction
temperature (Tj) will rise which will activate the TSD circuit [Tj ≥175 °C (Typ)] that will turn OFF output MOSFET. When
the Tj falls below the TSD threshold, the circuits are automatically restored to normal operation. Note that the TSD
circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no circumstances,
should the TSD circuit be used in a set design or for any purpose other than protecting the IC from heat damage.
5.
Over Voltage Protection (OVP)
The device incorporates an over voltage protection circuit to minimize the output voltage overshoot when recovering
from strong load transients or output fault conditions. If the FB pin voltage exceeds Output Over Voltage Protection
Detection Voltage at 0.92 V(Typ), the MOSFET on the output stage is turned OFF to prevent the increase in the output
voltage. After the detection, the switching operation resumes if the output decreases and the over voltage state is
released. Output Over Voltage Protection Detection Voltage and release voltage have a hysteresis of 5 %.
VOUT
VOVP : 0.92 V(Typ)
hys : 5 %
FB
SW
Internal OVP
Signal
Figure 23. OVP Timing Chart
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BD9S000NUX-C
Selection of Components Externally Connected
Contact us if not use the recommended constant in this section.
Necessary parameters in designing the power supply are as follows:
Table 1. Application Specification
Parameter
Input Voltage
Output Voltage
Switching Frequency
Inductor Ripple Current
Output Capacitor
Soft Start Time
Maximum Output Current
Symbol
VIN
VOUT
fSW
ΔIL
COUT
tSS
IOUTMAX
Example Value
5.0 V
1.2 V
2.2 MHz(Typ)
0.25 A
10 μF
8.0 ms(Typ)
600 mA
Application Example
R3
VIN
VIN
PGD
EN
SW
PGD
CIN1
VEN
VOUT
L1
R100
SS
COUT1
R1
GND
FB
CSS
R2
Figure 24. Typical Application
1.
Switching Frequency
The switching frequency fSW is fixed at 2.2 MHz(Typ) inside the IC.
2.
Selection of Output Voltage Setting
The output voltage value can be set by the feedback resistance ratio.
VOUT
𝑉𝑂𝑈𝑇 =
𝑅1 +𝑅2
𝑅2
× 0.8 [V]
R1
FB
R2
SW Minimum ON Time that BD9S000NUX-C can output
stably in the entire load range is 80 ns.
Use this value to calculate the input and output conditions
that satisfy the following equation
0.8 V(Typ)
80 [ns] ≤
𝑉𝑂𝑈𝑇
𝑉𝐼𝑁 × 𝑓𝑆𝑊
Figure 25. Feedback Resistor Circuit
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BD9S000NUX-C
Selection of Components Externally Connected – continued
3.
Selection of Input Capacitor
Please use ceramic type capacitor for the input capacitor CIN1. CIN1 is used to suppress the input ripple noise and this
capacitor is effective by being placed as close as possible to the VIN pin. Set the capacitor value for CIN1 so that it does
not fall to 4.7 μF against the capacitor value variances, temperature characteristics, DC bias characteristics, aging
characteristics, and etc. Please use components which are comparatively same with the components used in
“Application Example” on page 18. Moreover, factors like the PCB layout and the position of the capacitor may lead to IC
malfunction. Please refer to “Notes on the PCB layout Design” on page 28 and 29.
In addition, the capacitor with value 0.1 μF can be added to suppress the high frequency noise as an option.
4.
Selection of Output LC Filter
In order to supply a continuous current to the load, the DC/DC converter requires an LC filter for smoothing the output
voltage. Please use the inductor with value 1.5 μH or 2.2 μH.
VIN
IL
Inductor Saturation Current > IOUTMAX + ∆IL/2
∆IL
Driver
Maximum Output Current IOUTMAX
L1
VOUT
COUT
t
Figure 26. Waveform of Current Through Inductor
Figure 27. Output LC Filter Circuit
Inductor ripple current ΔIL can be represented by the following equation.
∆𝐼𝐿 = 𝑉𝑂𝑈𝑇 × (𝑉𝐼𝑁 − 𝑉𝑂𝑈𝑇 ) × 𝑉
1
𝐼𝑁 ×𝑓𝑆𝑊 ×𝐿1
= 276 [mA]
where
𝑉𝐼𝑁
𝑉𝑂𝑈𝑇
𝐿1
𝑓𝑆𝑊
is the 5.0 V
is the 1.2 V
is the 1.5 µH
is the 2.2 MHz (Switching Frequency)
The rated current of the inductor must be larger than the sum of the maximum output current and 1/2 of the inductor
ripple current ΔIL.
Please use ceramic type capacitor for the output capacitor C OUT. The capacitance value of COUT is selected in the range
between 10 μF and 22 μF. COUT affects the output ripple voltage characteristics. COUT must satisfy the required ripple
voltage characteristics.
The output ripple voltage can be represented by the following equation.
∆𝑉𝑅𝑃𝐿 = ∆𝐼𝐿 × (𝑅𝐸𝑆𝑅 + 8×𝐶
1
𝑂𝑈𝑇 ×𝑓𝑆𝑊
) [V]
Where
𝑅𝐸𝑆𝑅
is the Equivalent Series Resistance (ESR) of the output capacitor
The output ripple voltage ΔVRPL can be represented by the following equation.
∆𝑉𝑅𝑃𝐿 = 0.276 𝐴 × (10 𝑚𝛺 + 8×10
1
𝜇𝐹×2.2 𝑀𝐻𝑧
) = 4.33 [mV]
where
𝐶𝑂𝑈𝑇
𝑅𝐸𝑆𝑅
is the 10 µF
is the 10 mΩ
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BD9S000NUX-C
4.
Selection of Output LC Filter – continued
In addition, for the total value of capacitance in the output line COUT(Max), choose a capacitance value less than the
value obtained by the following equation.
𝐶𝑂𝑈𝑇(𝑀𝑎𝑥) <
(𝑡𝑆𝑆(𝑀𝑖𝑛) −200 𝜇𝑠)×(𝐼𝑂𝐶𝑃(𝑀𝑖𝑛) −𝐼𝑆𝑊𝑆𝑇𝐴𝑅𝑇 )
𝑉𝑂𝑈𝑇
[F]
where:
𝐼𝑆𝑊𝑆𝑇𝐴𝑅𝑇
𝐼𝑂𝐶𝑃(𝑀𝑖𝑛)
𝑡𝑆𝑆(𝑀𝑖𝑛)
𝑉𝑂𝑈𝑇
is the maximum output current during startup
is the minimum OCP operation SW current 0.8 A
is the minimum Soft Start Time
is the output voltage
Startup failure may happen if the limits from the above-mentioned are exceeded. Especially if the capacitance value is
large, over current protection may be activated by the inrush current at startup and prevented to turn on the output.
Please confirm this on the actual application.
Stable transient response and the loop is dependent to COUT. Actually, characteristics will vary depending on PCB layout,
arrangement of wiring, kinds of parts used and use conditions(temperature, etc.). Please be sure to check stability and
responsiveness with the actual application.
5.
Selection of Soft Start Capacitor
Turning the EN pin signal high activates the soft start function. This causes the output voltage to rise gradually while the
current at startup is placed under control. This allows the prevention of output voltage overshoot and inrush current. The
rise time tSS_EXT depends on the value of the capacitor connected to the SS pin. The capacitance value should be set to
0.1 μF or less.
VEN
𝑡𝑆𝑆_𝐸𝑋𝑇 =
(𝐶𝑆𝑆 ×𝑉𝐹𝐵 )
𝐼𝑆𝑆
VENH
[s]
VENL
0
t
where
𝑡𝑆𝑆_𝐸𝑋𝑇
𝐶𝑆𝑆
𝑉𝐹𝐵
𝐼𝑆𝑆
is the Soft Start Time
VOUT
is the Capacitor connected to the SS pin
is the FB pin Voltage 0.8 V(Typ)
is the SS Charge Current 1.0 µA(Typ)
0
t
tSS_EXT
With CSS=0.01 μF
𝑡𝑆𝑆_𝐸𝑋𝑇 =
t_wait
200 µs(Typ)
(0.01 𝜇𝐹×0.8 𝑉)
1.0 𝜇𝐴
= 8.0 [ms]
Figure 28. Soft Start Timing chart
Turning the EN pin High without connecting capacitor to the SS pin and keeping the SS pin either OPEN condition or 10
kΩ to 100 kΩ pull up condition to power source, the output will rise in 1 ms(Typ).
Recommended Parts Manufacturer List
Shown below is the list of the recommended parts manufacturers for reference.
Table 2
Device
Type
Manufacturer
C
Ceramic capacitors
Murata
www.murata.com
C
Ceramic capacitors
TDK
product.tdk.com
L
Inductors
Coilcraft
www.coilcraft.com
L
Inductors
Cyntec
www.cyntec.com
L
Inductors
Murata
www.murata.com
L
Inductors
Sumida
www.sumida.com
L
Inductors
TDK
product.tdk.com
R
Resistors
ROHM
www.rohm.com
www.rohm.com
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BD9S000NUX-C
Application Example 1
Table 3. Specification Example 1
Parameter
Product Name
Supply Voltage
Output Voltage
Soft Start Time
Maximum Output Current
Operation Temperature Range
Symbol
IC
VIN
VOUT
tSS
IOUTMAX
Ta
Example Value
BD9S000NUX-C
5.0 V, 3.3 V
1.0 V
1.0 ms(Typ)
600 mA
-40 °C to +125 °C
R3
VIN
VIN
PGD
EN
SW
PGD
CIN1
VEN
VOUT
L1
R100
SS
COUT1
C1
GND
COUT2
R1
FB
CSS
R2
Figure 29. Reference Circuit 1
Table 4. Parts List 1
No
Package
Parameters
Part Name(Series)
L1
COUT1
Type
Manufacturer
2016
1.5 μH
TFM201610ALMA1R5M
Inductor
TDK
2012
10 μF, X7R, 6.3 V
GCM21BR70J106K
Ceramic Capacitor
Murata
COUT2
2012
10 μF, X7R, 6.3 V
GCM21BR70J106K
Ceramic Capacitor
Murata
CIN1
2012
10 μF, X7R, 10 V
GCM21BR71A106K
Ceramic Capacitor
Murata
R100
-
SHORT
-
-
-
R1
1005
7.5 kΩ, 1 %, 1/16 W
MCR01MZPF7501
Chip Resistor
ROHM
R2
1005
30 kΩ, 1 %, 1/16 W
MCR01MZPF3002
Chip Resistor
ROHM
R3
1005
100 kΩ, 1 %, 1/16 W
MCR01MZPF1003
Chip Resistor
ROHM
CSS
-
-
-
-
-
C1
-
-
-
-
-
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BD9S000NUX-C
Characteristic Data (Application Examples 1)
VIN = VEN, Ta = 25 °C
100
80
180
VIN = 5.0 V
90
60
135
40
90
20
45
0
0
60
VIN = 5.0 V
50
Gain[dB]
Efficiency [%]
70
VIN = 3.3 V
40
-20
-45
30
Phase[deg]
80
Gain
-40
20
-90
Phase
-60
10
0
0.0
0.1
0.2
0.3
0.4
Output Current [A]
0.5
-135
-80
0.6
1
Figure 30. Efficiency vs Output Current
10
100
Frequency[kHz]
-180
1000
Figure 31. Frequency Characteristics
(IOUT=0.6 A)
Time: 500 ns/div
Time: 20 μs/div
VOUT: 20 mV/div
VOUT: 100 mV/div
IOUT: 200 mA/div
IOUT: 300 mA/div
Figure 32. Load Transient Response
(IOUT=0 A↔0.6 A)
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Figure 33. Output Ripple Voltage
(IOUT=0.6 A)
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BD9S000NUX-C
Application Example 2
Table 5. Specification Example 2
Parameter
Product Name
Supply Voltage
Output Voltage
Soft Start Time
Maximum Output Current
Operation Temperature Range
Symbol
IC
VIN
VOUT
tSS
IOUTMAX
Ta
Example Value
BD9S000NUX-C
5.0 V, 3.3 V
1.2 V
1.0 ms(Typ)
600 mA
-40 °C to +125 °C
R3
VIN
VIN
PGD
EN
SW
PGD
CIN1
VEN
VOUT
L1
R100
SS
COUT1
C1
GND
R1
FB
CSS
R2
Figure 34. Reference Circuit 2
Table 6. Parts List 2
No
Package
Parameters
Part Name(Series)
L1
COUT1
Type
Manufacturer
2016
1.5 μH
TFM201610ALMA1R5M
Inductor
TDK
2012
10 μF, X7R, 6.3 V
GCM21BR70J106K
Ceramic Capacitor
Murata
CIN1
2012
10 μF, X7R, 10 V
GCM21BR71A106K
Ceramic Capacitor
Murata
R100
-
SHORT
-
-
-
R1
1005
10 kΩ, 1 %, 1/16 W
MCR01MZPF1002
Chip Resistor
ROHM
R2
1005
20 kΩ, 1 %, 1/16 W
MCR01MZPF2002
Chip Resistor
ROHM
R3
1005
100 kΩ, 1 %, 1/16 W
MCR01MZPF1003
Chip Resistor
ROHM
CSS
-
-
-
-
-
C1
-
-
-
-
-
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BD9S000NUX-C
Characteristic Data (Application Examples 2)
VIN = VEN, Ta = 25 °C
100
80
180
VIN = 5.0 V
90
60
135
40
90
20
45
0
0
60
VIN = 5.0 V
VIN = 3.3 V
Gain[dB]
Efficiency [%]
70
50
40
-20
-45
30
Phase[deg]
80
Gain
-40
20
-90
Phase
-60
10
0
0.0
0.1
0.2
0.3
0.4
Output Current [A]
0.5
-80
0.6
1
Figure 35. Efficiency vs Output Current
10
100
Frequency[kHz]
-180
1000
Figure 36. Frequency Characteristic
(IOUT=0.6 A)
Time: 500 ns/div
Time: 20 μs/div
VOUT: 20 mV/div
VOUT: 100 mV/div
IOUT: 200 mA/div
IOUT: 300 mA/div
Figure 37. Load Transient Response
(IOUT=0 A↔0.6 A)
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Figure 38. Output Ripple Voltage
(IOUT=0.6 A)
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Application Example 3
Table 7. Specification Example 3
Parameter
Product Name
Supply Voltage
Output Voltage
Soft Start Time
Maximum Output Current
Operation Temperature Range
Symbol
IC
VIN
VOUT
tSS
IOUTMAX
Ta
Example Value
BD9S000NUX-C
5.0 V, 3.3 V
1.5 V
1.0 ms(Typ)
600 mA
-40 °C to +125 °C
R3
VIN
VIN
PGD
EN
SW
PGD
CIN1
VEN
VOUT
L1
R100
SS
COUT1
C1
GND
R1
FB
CSS
R2
Figure 39. Reference Circuit 3
Table 8. Parts List 3
No
Package
Parameters
Part Name(Series)
L1
COUT1
Type
Manufacturer
2016
1.5 μH
TFM201610ALMA1R5M
Inductor
TDK
2012
10 μF, X7R, 6.3 V
GCM21BR70J106K
Ceramic Capacitor
Murata
CIN1
2012
10 μF, X7R, 10 V
GCM21BR71A106K
Ceramic Capacitor
Murata
R100
-
SHORT
-
-
-
R1
1005
16 kΩ, 1 %, 1/16 W
MCR01MZPF1602
Chip Resistor
ROHM
R2
1005
18 kΩ, 1 %, 1/16 W
MCR01MZPF1802
Chip Resistor
ROHM
R3
1005
100 kΩ, 1 %, 1/16 W
MCR01MZPF1003
Chip Resistor
ROHM
CSS
-
-
-
-
-
C1
-
-
-
-
-
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BD9S000NUX-C
Characteristic Data (Application Examples 3)
VIN = VEN, Ta = 25 °C
100
80
180
VIN = 5.0 V
90
60
135
40
90
20
45
0
0
60
VIN = 5.0 V
VIN = 3.3 V
Gain[dB]
Efficiency [%]
70
50
40
-20
-45
Phase[deg]
80
30
20
-40
10
-60
0
0.0
0.1
0.2
0.3
0.4
Output Current [A]
0.5
Gain
-90
Phase
-135
-80
0.6
1
Figure 40. Efficiency vs Output Current
10
100
Frequency[kHz]
-180
1000
Figure 41. Frequency Characteristics
(IOUT=0.6 A)
Time: 500 ns/div
Time: 20 μs/div
VOUT: 20 mV/div
VOUT: 100 mV/div
IOUT: 200 mA/div
IOUT: 300 mA/div
Figure 42. Load Transient Response
(IOUT=0 A↔0.6 A)
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Figure 43. Output Ripple Voltage
(IOUT=0.6 A)
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Application Example 4
Table 9. Specification Example 4
Parameter
Product Name
Supply Voltage
Output Voltage
Soft Start Time
Maximum Output Current
Operation Temperature Range
Symbol
IC
VIN
VOUT
tSS
IOUTMAX
Ta
Example Value
BD9S000NUX-C
5.0 V, 3.3 V
1.8 V
1.0 ms(Typ)
600 mA
-40 °C to +125 °C
R3
VIN
VIN
PGD
EN
SW
PGD
CIN1
VEN
VOUT
L1
R100
SS
COUT1
C1
GND
R1
FB
CSS
R2
Figure 44. Reference Circuit 4
Table 10. Parts List 4
No
Package
Parameters
Part Name(Series)
L1
COUT1
Type
Manufacturer
2016
2.2 μH
TFM201610ALMA2R2M
Inductor
TDK
2012
10 μF, X7R, 6.3 V
GCM21BR70J106K
Ceramic Capacitor
Murata
CIN1
2012
10 μF, X7R, 10 V
GCM21BR71A106K
Ceramic Capacitor
Murata
R100
-
SHORT
-
-
-
R1
1005
30 kΩ, 1 %, 1/16 W
MCR01MZPF3002
Chip Resistor
ROHM
R2
1005
24 kΩ, 1 %, 1/16 W
MCR01MZPF2402
Chip Resistor
ROHM
R3
1005
100 kΩ, 1 %, 1/16 W
MCR01MZPF1003
Chip Resistor
ROHM
CSS
-
-
-
-
-
C1
-
-
-
-
-
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BD9S000NUX-C
Characteristic Data (Application Examples 4)
VIN = VEN, Ta = 25 °C
80
100
180
VIN = 5.0 V
90
60
135
40
90
20
45
0
0
80
VIN = 5.0 V
VIN = 3.3 V
50
40
-20
-45
30
Gain
-40
20
-90
Phase
-60
10
0
0.0
0.1
0.2
0.3
0.4
Output Current [A]
0.5
-135
-80
0.6
Phase[deg]
60
Gain[dB]
Efficiency [%]
70
1
10
100
-180
1000
Frequency[kHz]
Figure 45. Efficiency vs Output Current
Figure 46. Frequency Characteristics
(IOUT =0.6 A)
Time: 20 μs/div
Time: 500 ns/div
VOUT: 20 mV/div
VOUT: 100 mV/div
IOUT: 200 mA/div
IOUT: 300 mA/div
Figure 47. Load Transient Response
(IOUT=0 A↔0.6 A)
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Figure 48. Output Ripple Voltage
(IOUT=0.6 A)
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Application Example 5
Table 11. Specification Example 5
Parameter
Product Name
Supply Voltage
Output Voltage
Soft Start Time
Maximum Output Current
Operation Temperature Range
Symbol
IC
VIN
VOUT
tSS
IOUTMAX
Ta
Example Value
BD9S000NUX-C
5.0 V
3.3 V
1.0 ms(Typ)
600 mA
-40 °C to +125 °C
R3
VIN
VIN
PGD
EN
SW
PGD
CIN1
VEN
VOUT
L1
R100
SS
COUT1
C1
GND
R1
FB
CSS
R2
Figure 49. Reference Circuit 5
Table 12. Parts List 5
No
Package
Parameters
Part Name(Series)
L1
COUT1
Type
Manufacturer
2016
2.2 μH
TFM201610ALMA2R2M
Inductor
TDK
2012
10 μF, X7R, 10 V
GCM21BR71A106K
Ceramic Capacitor
Murata
CIN1
2012
10 μF, X7R, 10 V
GCM21BR71A106K
Ceramic Capacitor
Murata
R100
-
SHORT
-
-
-
R1
1005
75 kΩ, 1 %, 1/16 W
MCR01MZPF7502
Chip Resistor
ROHM
R2
1005
24 kΩ, 1 %, 1/16 W
MCR01MZPF2402
Chip Resistor
ROHM
R3
1005
100 kΩ, 1 %, 1/16 W
MCR01MZPF1003
Chip Resistor
ROHM
CSS
-
-
-
-
-
C1
-
-
-
-
-
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Characteristic Data (Application Examples 5)
VIN = VEN, Ta = 25 °C
100
80
180
VIN = 5.0 V
90
60
135
40
90
20
45
0
0
70
Gain[dB]
Efficiency [%]
VIN = 5.0 V
60
50
40
-20
-45
30
Gain
-40
20
Phase[deg]
80
-90
Phase
-60
10
0
-135
-80
0.0
0.1
0.2
0.3
0.4
Output Current [A]
0.5
0.6
1
Figure 50. Efficiency vs Output Current
Time: 20 μs/div
-180
1000
Figure 51. Frequency Characteristics
(IOUT=0.6 A)
Time: 500 ns/div
VOUT: 20 mV/div
VOUT: 100 mV/div
IOUT: 200 mA/div
IOUT: 300 mA/div
Figure 52. Load Transient Response
(IOUT=0 A↔0.6 A)
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10
100
Frequency[kHz]
Figure 53. Output Ripple Voltage
(IOUT=0.6 A)
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PCB Layout Design
PCB layout design for DC/DC converter is very important. Appropriate layout can avoid various problems concerning power
supply circuit. Figure 54-a to 54-c show the current path in a buck DC/DC converter circuit. The Loop 1 in Figure 54-a is a
current path when H-side switch is ON and L-side switch is OFF, the Loop 2 in Figure 54-b is when H-side switch is OFF and
L-side switch is ON. The thick line in Figure 54-c shows the difference between Loop1 and Loop2. The current in thick line
change sharply each time the switching element H-side and L-side switch change from OFF to ON, and vice versa. These
sharp changes induce a waveform with harmonics in this loop. Therefore, the loop area of thick line that is consisted by input
capacitor and IC should be as small as possible to minimize noise. For more details, refer to application note of switching
regulator series “PCB Layout Techniques of Buck Converter”.
Loop1
VIN
H-side Switch
VOUT
L
CIN
COUT
L-side Switch
GND
GND
Figure 54-a. Current Path when H-side Switch = ON, L-side Switch = OFF
VIN
VOUT
L
H-side Switch
CIN
COUT
Loop2
L-side Switch
GND
GND
Figure 54-b. Current Path when H-side Switch = OFF, L-side Switch = ON
VIN
VOUT
L
CIN
COUT
H-side FET
L-side FET
GND
GND
Figure 54-c. Difference of Current and Critical Area in Layout
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PCB Layout Design – continued
When designing the PCB layout, please pay extra attention to the following points:
• Connect the input capacitor CIN as close as possible to the VIN pin on the same plane as the IC.
• Switching nodes such as SW are susceptible to noise due to AC coupling with other nodes. Route the inductor pattern as
thick and as short as possible.
• R1 and R2 shall be located as close as possible to the FB pin and the wiring between R1 and R2 to the FB pin shall be as
short as possible.
• Provide line connected to FB far from the SW nodes.
• R100 is provided for the measurement of feedback frequency characteristics (optional). By inserting a resistor into R100, it
is possible to measure the frequency characteristics of feedback (phase margin) using FRA etc. R100 is short-circuited
for normal use.
R2
R1
Css
IC
R100
CIN
L1
COU T
Example of Evaluation Board Layout (Top View)
Example of Evaluation Board Layout (Bottom View)
Figure 55. Example of Evaluation Board Layout
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Power Dissipation
For thermal design, be sure to operate the IC within the following conditions.
(Since the temperatures described hereunder are all guaranteed temperatures, take margin into account.)
1.
2.
The ambient temperature Ta is to be 125 °C or less.
The chip junction temperature Tj is to be 150 °C or less.
The chip junction temperature Tj can be considered in the following two patterns:
1.
To obtain Tj from the package surface center temperature Tt in actual use
𝑇𝑗 = 𝑇𝑡 + 𝜓𝐽𝑇 × 𝑊 [°C]
2.
To obtain Tj from the ambient temperature Ta
𝑇𝑗 = 𝑇𝑎 + 𝜃𝐽𝐴 × 𝑊 [°C]
Where:
𝜓𝐽𝑇
𝜃𝐽𝐴
is junction to top characterization parameter (Refer to page 5)
is junction to ambient (Refer to page 5)
The heat loss W of the IC can be obtained by the formula shown below:
𝑉𝑂𝑈𝑇
𝑉𝑂𝑈𝑇
+ 𝑅𝑂𝑁𝐿 × 𝐼𝑂𝑈𝑇 2 (1 −
)
𝑉𝐼𝑁
𝑉𝐼𝑁
1
+𝑉𝐼𝑁 × 𝐼𝐶𝐶 + 2 × (𝑡𝑟 + 𝑡𝑓) × 𝑉𝐼𝑁 × 𝐼𝑂𝑈𝑇 × 𝑓𝑆𝑊 [W]
𝑊 = 𝑅𝑂𝑁𝐻 × 𝐼𝑂𝑈𝑇 2 ×
Where:
𝑅𝑂𝑁𝐻
𝑅𝑂𝑁𝐿
𝐼𝑂𝑈𝑇
𝑉𝑂𝑈𝑇
𝑉𝐼𝑁
𝐼𝐶𝐶
𝑡𝑟
𝑡𝑓
𝑓𝑆𝑊
is the High Side FET ON Resistance (Refer to page 6) [Ω]
is the Low Side FET ON Resistance (Refer to page 6) [Ω]
is the Output Current [A]
is the Output Voltage [V]
is the Input Voltage [V]
is the Circuit Current (Refer to page 6) [A]
is the Switching Rise Time [s] (Typ:4 ns)
is the Switching Fall Time [s] (Typ:3 ns)
is the Switching Frequency (Refer to page 6) [Hz]
tr
(4 ns)
tf
(3 ns)
VIN
1.
𝑅𝑂𝑁𝐻 × 𝐼𝑂𝑈𝑇 2
2.
𝑅𝑂𝑁𝐿 × 𝐼𝑂𝑈𝑇 2
1
VSW
3.
1
2
× (𝑡𝑟 + 𝑡𝑓) × 𝑉𝐼𝑁 × 𝐼𝑂 × 𝑓𝑆𝑊
GND
3
2
1
𝑓𝑆𝑊
Figure 56. SW Waveform
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I/O Equivalent Circuits(Note 1)
1. 2. SW
3. SS
VIN
VIN
20 kΩ
SW
SS
GND
625 Ω
GND
100 kΩ
GND
GND
GND
4. FB
5. PGD
20 kΩ
FB
PGD
10 kΩ
50 Ω
GND
10 kΩ
GND
GND
10 kΩ
6. EN
100 kΩ
EN
150 kΩ
GND
10 kΩ
850 kΩ
GND GND
GND
(Note 1) Resistance value is Typical.
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Operational Notes
1.
Reverse Connection of Power Supply
Connecting the power supply in reverse polarity can damage the IC. Take precautions against reverse polarity when
connecting the power supply, such as mounting an external diode between the power supply and the IC’s power
supply pins.
2.
Power Supply Lines
Design the PCB layout pattern to provide low impedance supply lines. Furthermore, connect a capacitor to ground at
all power supply pins. Consider the effect of temperature and aging on the capacitance value when using electrolytic
capacitors.
3.
Ground Voltage
Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition. However,
pins that drive inductive loads (e.g. motor driver outputs, DC-DC converter outputs) may inevitably go below ground
due to back EMF or electromotive force. In such cases, the user should make sure that such voltages going below
ground will not cause the IC and the system to malfunction by examining carefully all relevant factors and conditions
such as motor characteristics, supply voltage, operating frequency and PCB wiring to name a few.
4.
Ground Wiring Pattern
When using both small-signal and large-current ground traces, the two ground traces should be routed separately but
connected to a single ground at the reference point of the application board to avoid fluctuations in the small-signal
ground caused by large currents. Also ensure that the ground traces of external components do not cause variations
on the ground voltage. The ground lines must be as short and thick as possible to reduce line impedance.
5.
Recommended Operating Conditions
The function and operation of the IC are guaranteed within the range specified by the recommended operating
conditions. The characteristic values are guaranteed only under the conditions of each item specified by the electrical
characteristics.
6.
Inrush Current
When power is first supplied to the IC, it is possible that the internal logic may be unstable and inrush current may flow
instantaneously due to the internal powering sequence and delays, especially if the IC has more than one power
supply. Therefore, give special consideration to power coupling capacitance, power wiring, width of ground wiring, and
routing of connections.
7.
Testing on Application Boards
When testing the IC on an application board, connecting a capacitor directly to a low-impedance output pin may
subject the IC to stress. Always discharge capacitors completely after each process or step. The IC’s power supply
should always be turned off completely before connecting or removing it from the test setup during the inspection
process. To prevent damage from static discharge, ground the IC during assembly and use similar precautions during
transport and storage.
8.
Inter-pin Short and Mounting Errors
Ensure that the direction and position are correct when mounting the IC on the PCB. Incorrect mounting may result in
damaging the IC. Avoid nearby pins being shorted to each other especially to ground, power supply and output pin.
Inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment) and
unintentional solder bridge deposited in between pins during assembly to name a few.
9.
Unused Input Pins
Input pins of an IC are often connected to the gate of a MOS transistor. The gate has extremely high impedance and
extremely low capacitance. If left unconnected, the electric field from the outside can easily charge it. The small
charge acquired in this way is enough to produce a significant effect on the conduction through the transistor and
cause unexpected operation of the IC. So unless otherwise specified, unused input pins should be connected to the
power supply or ground line.
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BD9S000NUX-C
Operational Notes – continued
10. Regarding the Input Pin of the IC
This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them
isolated. P-N junctions are formed at the intersection of the P layers with the N layers of other elements, creating a
parasitic diode or transistor. For example (refer to figure below):
When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.
When GND > Pin B, the P-N junction operates as a parasitic transistor.
Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual
interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to
operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should be
avoided.
Resistor
Transistor (NPN)
Pin A
Pin B
C
E
Pin A
N
P+
P
N
N
P+
N
Pin B
B
Parasitic
Elements
N
P+
N P
N
P+
B
N
C
E
Parasitic
Elements
P Substrate
P Substrate
GND
GND
Parasitic
Elements
GND
Parasitic
Elements
GND
N Region
close-by
Figure 57. Example of monolithic IC structure
11. Ceramic Capacitor
When using a ceramic capacitor, determine a capacitance value considering the change of capacitance with
temperature and the decrease in nominal capacitance due to DC bias and others.
12. Thermal Shutdown Circuit(TSD)
This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always
be within the IC’s maximum junction temperature rating. If however the rating is exceeded for a continued period, the
junction temperature (Tj) will rise which will activate the TSD circuit that will turn OFF power output pins. When the Tj
falls below the TSD threshold, the circuits are automatically restored to normal operation.
Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no
circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from
heat damage.
13. Over Current Protection Circuit (OCP)
This IC incorporates an integrated overcurrent protection circuit that is activated when the load is shorted. This
protection circuit is effective in preventing damage due to sudden and unexpected incidents. However, the IC should
not be used in applications characterized by continuous operation or transitioning of the protection circuit.
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BD9S000NUX-C
Ordering Information
B
D
9
S
0
Part Number
0
0
N
U
X
Package
VSON008X2020
-
CE2
Product class
C for Automotive applications
Packaging and forming specification
E2: Embossed tape and reel
Marking Diagrams
VSON008X2020 (TOP VIEW)
Part Number Marking
D9S
LOT Number
0 0 0
Pin 1 Mark
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BD9S000NUX-C
Physical Dimension and Packing Information
Package Name
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BD9S000NUX-C
Revision History
Date
Revision
05.Apr.2018
001
Changes
New Release
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Notice
Precaution on using ROHM Products
1.
(Note 1)
If you intend to use our Products in devices requiring extremely high reliability (such as medical equipment
,
aircraft/spacecraft, nuclear power controllers, etc.) and whose malfunction or failure may cause loss of human life,
bodily injury or serious damage to property (“Specific Applications”), please consult with the ROHM sales
representative in advance. Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way
responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any
ROHM’s Products for Specific Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASSⅢ
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅣ
CLASSⅢ
2.
ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate
safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which
a failure or malfunction of our Products may cause. The following are examples of safety measures:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure
3.
Our Products are not designed under any special or extraordinary environments or conditions, as exemplified below.
Accordingly, ROHM shall not be in any way responsible or liable for any damages, expenses or losses arising from the
use of any ROHM’s Products under any special or extraordinary environments or conditions. If you intend to use our
Products under any special or extraordinary environments or conditions (as exemplified below), your independent
verification and confirmation of product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of
flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Products in places subject to dew condensation
4.
The Products are not subject to radiation-proof design.
5.
Please verify and confirm characteristics of the final or mounted products in using the Products.
6.
In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7.
De-rate Power Dissipation depending on ambient temperature. When used in sealed area, confirm that it is the use in
the range that does not exceed the maximum junction temperature.
8.
Confirm that operation temperature is within the specified range described in the product specification.
9.
ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1.
When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2.
In principle, the reflow soldering method must be used on a surface-mount products, the flow soldering method must
be used on a through hole mount products. If the flow soldering method is preferred on a surface-mount products,
please consult with the ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice-PAA-E
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.003
Precautions Regarding Application Examples and External Circuits
1.
If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2.
You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses
incurred by you or third parties arising from the use of such information.
Precaution for Electrostatic
This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper
caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be
applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron,
isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control).
Precaution for Storage / Transportation
1.
Product performance and soldered connections may deteriorate if the Products are stored in the places where:
[a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2
[b] the temperature or humidity exceeds those recommended by ROHM
[c] the Products are exposed to direct sunshine or condensation
[d] the Products are exposed to high Electrostatic
2.
Even under ROHM recommended storage condition, solderability of products out of recommended storage time period
may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is
exceeding the recommended storage time period.
3.
Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads
may occur due to excessive stress applied when dropping of a carton.
4.
Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of
which storage time is exceeding the recommended storage time period.
Precaution for Product Label
A two-dimensional barcode printed on ROHM Products label is for ROHM’s internal use only.
Precaution for Disposition
When disposing Products please dispose them properly using an authorized industry waste company.
Precaution for Foreign Exchange and Foreign Trade act
Since concerned goods might be fallen under listed items of export control prescribed by Foreign exchange and Foreign
trade act, please consult with ROHM in case of export.
Precaution Regarding Intellectual Property Rights
1.
All information and data including but not limited to application example contained in this document is for reference
only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any
other rights of any third party regarding such information or data.
2.
ROHM shall not have any obligations where the claims, actions or demands arising from the combination of the
Products with other articles such as components, circuits, systems or external equipment (including software).
3.
No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any
third parties with respect to the Products or the information contained in this document. Provided, however, that ROHM
will not assert its intellectual property rights or other rights against you or your customers to the extent necessary to
manufacture or sell products containing the Products, subject to the terms and conditions herein.
Other Precaution
1.
This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.
2.
The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written
consent of ROHM.
3.
In no event shall you use in any way whatsoever the Products and the related technical information contained in the
Products or this document for any military purposes, including but not limited to, the development of mass-destruction
weapons.
4.
The proper names of companies or products described in this document are trademarks or registered trademarks of
ROHM, its affiliated companies or third parties.
Notice-PAA-E
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.003
Datasheet
General Precaution
1. Before you use our Products, you are requested to carefully read this document and fully understand its contents.
ROHM shall not be in any way responsible or liable for failure, malfunction or accident arising from the use of any
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this document is current as of the issuing date and subject to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the latest information with a ROHM sales
representative.
3.
The information contained in this document is provided on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate and/or error-free. ROHM shall not be in any way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccuracy or errors of or
concerning such information.
Notice – WE
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