Datasheet
2.7V to 5.5V Input, 3A Integrated MOSFET
Single Synchronous Buck DC/DC Converter
BD9A302QWZ
General Description
Key Specifications
BD9A302QWZ is a synchronous buck DC/DC
converter with built-in low on-resistance power
MOSFETs. This IC is capable of providing current up
to 3A. The SLLMTM control provides excellent
efficiency characteristics in light-load conditions which
make the product ideal for equipment and devices that
demand minimal standby power consumption. The
oscillating frequency is high at 1MHz using a small
value of inductor. BD9A302QWZ is a current mode
control DC/DC converter and features high-speed
transient response. Phase compensation can also be
set easily.
Input Voltage Range:
2.7V to 5.5V
Output Voltage Range:
0.8V to VIN x 0.7V
Output Current:
3A(Max)
Switching Frequency:
1MHz(Typ)
High-Side MOSFET ON-Resistance: 50mΩ (Typ)
Low-Side MOSFET ON-Resistance: 50mΩ (Typ)
Standby Current:
0μA (Typ)
Package
W (Typ) x D (Typ) x H (Max)
2.00mm x 2.00mm x 0.40mm
UMMP008AZ020
Features
Single Synchronous Buck DC/DC Converter
SLLMTM (Simple Light Load Mode) Control
Over Current Protection
Short Circuit Protection
Thermal Shutdown Protection
Under Voltage Lockout Protection
UMMP008AZ020 Package
(Backside Heat Dissipation)
Applications
UMMP008AZ020
Step-Down Power Supply for DSPs,
FPGAs, Microprocessors, etc.
Laptop PCs / Tablet PCs / Servers
LCD TVs
Storage Devices (HDDs/SSDs)
Printers, OA Equipment
Distributed Power Supplies,
Secondary Power Supplies
Typical Application Circuit
BD9A302QWZ
VIN
VIN
BST
MODE
10µF
0.1µF
Enable
MODE
0.1µF
VOUT
SW
EN
1.5µH
ITH
22µF×2
R2
FB
RITH
GND
R1
CITH
Figure 1. Application Circuit
〇Product structure : Silicon monolithic integrated circuit
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〇This product has no designed protection against radioactive rays
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Pin Configuration
(TOP VIEW)
VIN
1
8
GND
EN
2
7
FB
BST
3
6
ITH
SW
4
5
MODE
E-PAD
Figure 2. Pin Configuration
Pin Descriptions
Pin No.
Pin Name
1
VIN
Power supply terminal for the switching regulator and control circuit.
Connecting 10µF and 0.1µF ceramic capacitors are recommended.
2
EN
Enable terminal.
Turning this terminal signal Low (0.8V or lower) forces the device to enter the shutdown mode.
Turning this terminal signal High (2.0V or higher) enables the device. The EN terminal must be
properly terminated.
3
BST
Terminal for bootstrap.
Connect a bootstrap capacitor of 0.1µF between this terminal and SW terminal.
The voltage of the bootstrap capacitor is the gate drive voltage of the High-Side MOSFET.
SW
Switch terminal. The SW terminal is connected to the source of the High-Side MOSFET and
drain of the Low-Side MOSFET. Connect a bootstrap capacitor of 0.1µF between the SW
terminal and BST terminal. In addition, connect an inductor of 1.5µH considering the direct
current superimposition characteristic.
5
MODE
Terminal for setting switching control mode. Turning this terminal signal Low (0.2V or lower)
forces the device to operate in fixed frequency PWM mode. Turning this terminal signal High
(0.8V or higher) enables the SLLM control and the mode is automatically switched between
SLLM control and fixed frequency PWM mode. Do not change this terminal voltage during
operation.
6
ITH
Terminal for the output of the error amplifier and the input of the current comparator.
Connect phase compensation components to this terminal.
7
FB
Inverting input terminal for the error amplifier.
8
GND
-
E-PAD
4
Function
Ground terminal for the output stage of the switching regulator and the control circuit.
Backside heat dissipation pad. Connecting to the PCB ground plane by using multiple vias
provides excellent heat dissipation characteristics.
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Block Diagram
1
MODE
VIN
5
EN
2
VREF
Error
Amplifier
FB
Current
Comparator
R
7
Q
S
SLOPE
CLK
OSC
VIN
Soft
Start
UVLO
Current
Sense/
Protect
3
+
BST
SW
4
Driver
Logic
VIN
SCP
ITH
6
OVP
GND
8
TSD
Figure 3. Block Diagram
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Description of Blocks
1.
VREF
The VREF block generates the internal reference voltage.
2.
UVLO
The UVLO block is for under voltage lockout protection. It will shut down the IC when the VIN terminal voltage falls to
2.45V (Typ) or lower. The threshold voltage has a hysteresis of 100mV (Typ).
3.
SCP
After the soft start is completed and when the feedback voltage of the output voltage has fallen below 0.4V (Typ) for
1ms (Typ), the SCP stops the operation for 16ms (Typ) and subsequently initiates restart.
4.
OVP
The over voltage protection function (OVP) compares the FB terminal voltage with the internal reference voltage. When
the FB terminal voltage exceeds 0.88V (Typ), it turns the output MOSFETs off. The output voltage returns with
hysteresis after the output voltage drops to normal operation level.
5.
TSD
The TSD block is for thermal protection. The thermal protection circuit shuts down the device when the internal
temperature of IC rises to 175C (Typ) or higher. Thermal protection circuit resets when the temperature falls. The
circuit has a hysteresis of 25°C (Typ).
6.
Soft Start
When EN terminal is switched High, Soft Start operates and the output voltage gradually rises. With the Soft Start
Function, overshoot of output voltage and rush current can be prevented. The internal soft start time is set to 1ms
(Typ).
7.
Error Amplifier
The error amplifier block compares the internal reference voltage with the feedback voltage of the output voltage. The
error and the ITH terminal voltage determine the switching duty. A soft start is applied at startup. The ITH terminal
voltage is limited by the internal slope voltage.
8.
Current Comparator
The Current Comparator block compares the output ITH terminal voltage of the error amplifier and the slope block
signal to determine the switching duty. In the event of over current, the current that flows through the High-Side
MOSFET is limited at each cycle of the switching frequency.
9.
OSC
This block is the oscillator.
10. Driver Logic
This block is the DC/DC driver. A signal from current comparator is applied to drive the MOSFETs.
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BD9A302QWZ
Absolute Maximum Ratings (Ta = 25°C)
Parameter
Input Voltage
EN Terminal Voltage
MODE Terminal Voltage
Voltage from GND to BST
Symbol
Rating
Unit
VIN
-0.3 to +7
V
VEN
-0.3 to +7
V
VMODE
-0.3 to +7
V
VBST
-0.3 to +14
V
ΔVBST
-0.3 to +7
V
FB Terminal Voltage
VFB
-0.3 to +7
V
ITH Terminal Voltage
VITH
-0.3 to +7
V
SW Terminal Voltage
VSW
-0.3 to VIN + 0.3
V
Storage Temperature Range
Tstg
-55 to +150
°C
Tjmax
150
°C
Voltage from SW to BST
Maximum Junction Temperature
Caution1: 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, increase the board size and copper area to prevent exceeding the maximum
junction temperature rating.
Thermal Resistance (Note 1)
Parameter
Symbol
Thermal Resistance (Typ)
Unit
1s(Note 3)
2s2p(Note 4)
θJA
376.0
67.8
°C/W
ΨJT
92.0
18.0
°C/W
UMMP008AZ020
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.
Layer Number of
Measurement Board
Single
Material
Board Size
FR-4
114.3mm x 76.2mm x 1.57mmt
Top
Copper Pattern
Thickness
Footprints and Traces
70μm
(Note 4) Using a PCB board based on JESD51-5, 7.
Layer Number of
Measurement Board
4 Layers
Thermal Via(Note 5)
Material
Board Size
FR-4
114.3mm x 76.2mm x 1.6mmt
Top
2 Internal Layers
Pitch
-
Diameter
Φ0.30mm
Bottom
Copper Pattern
Thickness
Copper Pattern
Thickness
Copper Pattern
Thickness
Footprints and Traces
70μm
74.2mm x 74.2mm
35μm
74.2mm x 74.2mm
70μm
(Note 5) This thermal via connects with the copper pattern of all layers.
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Recommended Operating Conditions
Parameter
Symbol
Min
Typ
Max
Unit
VIN
2.7
-
5.5
V
Operating Temperature Range
Topr
-40
-
+85
°C
Output Current
IOUT
0
-
3
A
VRANGE
0.8
-
VIN x 0.7
V
Input Voltage
Output Voltage Range
Electrical Characteristics (Unless otherwise specified Ta = 25°C, VIN = 5V, VEN = 5V)
Parameter
Symbol
Min
Typ
Max
Unit
Conditions
Standby Supply Current
ISTB
-
0
10
µA
VEN = GND
Operating Supply Current
ICC
-
350
500
µA
IOUT = 0mA
Non-switching
UVLO Detection Voltage
VUVLO1
2.35
2.45
2.55
V
VIN Falling
UVLO Release Voltage
VUVLO2
2.425
2.55
2.7
V
VIN Rising
EN Input High Level Voltage
VENH
2.0
-
VIN
V
EN Input Low Level Voltage
VENL
GND
-
0.8
V
IEN
-
5
10
µA
VMODEH
0.2
0.4
0.8
V
IMODE
-
10
20
µA
FB Terminal Voltage
VFB
0.792
0.8
0.808
V
FB Input Current
IFB
-
0
1
µA
VFB = 0.8V
ITH Sink Current
ITHSI
10
20
40
µA
VFB = 0.9V
ITH Source Current
ITHSO
10
20
40
µA
VFB = 0.7V
tSS
0.5
1.0
2.0
ms
fOSC
800
1000
1200
kHz
High Side FET ON Resistance
RONH
-
50
100
mΩ
Low Side FET ON Resistance
INPUT SUPPLY
ENABLE
EN Input Current
VEN = 5V
MODE
MODE Threshold Voltage
MODE Input Current
VMODE = 5V
Reference Voltage, Error Amplifier
Soft Start Time
SWITCHING FREQUENCY
Switching Frequency
SWITCH MOSFET
VBST – VSW = 5V
RONL
-
50
100
mΩ
High Side Output Leakage Current
ILH
-
0
10
µA
Non-switching
Low Side Output Leakage Current
ILL
-
0
10
µA
Non-switching
VSCP
0.28
0.4
0.52
V
SCP
Short Circuit Protection Detection
Voltage
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Typical Performance Curves
10.0
500
ICC [µA]
Operating Supply
Current : ICC [µA]
Standby Supply
Current : ISTB [µA]
ISTB [µA]
9.0
8.0
7.0
6.0
5.0
4.0
3.0
VIN = 5.0V
VIN = 2.7V
2.0
VIN = 5.0V
400
300
VIN = 2.7V
200
100
1.0
0.0
0
-40
-20
0
20
40
60
80
-40
-20
Temperature
[°C][°C]
Temperature
Figure 4. Standby Supply Current vs Temperature
20
40
Temperature
[°C]
Temperature [°C]
60
80
Figure 5. Operating Supply Current vs Temperature
1.20
0.808
1.15
0.806
VIN = 2.7V
VFB
[V]
FB Terminal
Voltage
: VFB [V]
FOSC [MHz]
Switching Frequency
: fOSC [MHz]
0
1.10
1.05
1.00
0.95
0.90
VIN = 5.0V
0.804
0.802
VIN = 2.7V
0.800
0.798
VIN = 5.0V
0.796
0.794
0.85
0.80
0.792
-40
-20
0
20
40
60
80
-40
0
20
40
60
80
Temperature
: Ta
[°C]
Temperature
[°C]
Temperature
[℃]
Temperature
[°C]
Temperature
[℃]
Figure 6. Switching Frequency vs Temperature
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Figure 7. FB Terminal Voltage vs Temperature
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40
40
35
35
ITH Source
Current
ITHSO
[µA] : ITHSO [µA]
ITH Sink
ITHSICurrent
[µA] : ITHSI [µA]
Typical Performance Curves - continued
30
VIN = 5.0V
25
20
30
VIN = 5.0V
25
20
VIN = 2.7V
15
15
VIN = 2.7V
10
10
-40
-20
0
20
40
60
-40
80
-20
20
40
60
80
Temperature
Temperature[°C]
[℃]
Temperature
[°C]
Temperature
[℃]
Figure 8. ITH Sink Current vs Temperature
Figure 9. ITH Source Current vs Temperature
0.8
20
VIN = 5.0V
18
0.7
MODE Input
Current
IMODE
[µA] : IMODE [µA]
MODE Threshold
Voltage
VMODEH
[V] : VMODEH [V]
0
0.6
0.5
0.4
0.3
16
VMODE = 5.0V
14
12
10
8
6
4
VMODE = 2.7V
2
0.2
0
-40
-20
0
20
40
60
80
-40
Temperature
[°C]
Temperature
[℃]
0
20
40
60
80
Temperature[℃]
[°C]
Temperature
Figure 10. MODE Threshold Voltage vs Temperature
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Figure 11. MODE Input Current vs Temperature
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BD9A302QWZ
Typical Performance Curves - continued
100
High Side FET ON
Resistance
: RONH [mΩ]
RONH
[mΩ]
Soft Start
TSSTime
[ms] : tSS [ms]
2.0
VIN = 2.7V
1.5
1.0
VIN = 5.0V
0.5
0.0
90
80
VIN = 2.7V
70
60
50
VIN = 3.3V
40
VIN = 5.0V
30
20
10
0
-40
-20
0
20
40
60
80
-40
-20
Temperature
Temperature[°C]
[℃]
Figure 12. Soft Start Time vs Temperature
20
40
Temperature
[°C]
Temperature [℃]
60
80
Figure 13. High Side FET ON Resistance vs Temperature
100
3.0
UVLO Threshold Voltage
: VUVLO1, VUVLO2 [V]
VUVLO [V]
Low Side FET R
ON
Resistance
: RONL [mΩ]
ONL
[mΩ]
0
90
VIN = 2.7V
80
70
60
50
40
VIN = 3.3V
30
VIN = 5.0V
20
10
0
2.9
2.8
2.7
Release (VIN Rising)
2.6
2.5
2.4
2.3
Detect (VIN Falling)
2.2
2.1
2.0
-40
-20
0
20
40
Temperature
[°C]
Temperature [℃]
60
80
-20
0
20
40
60
80
Temperature[℃]
[°C]
Temperature
Figure 14. Low Side FET ON Resistance vs Temperature
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Figure 15. UVLO Detection / Release Voltage
vs Temperature
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BD9A302QWZ
Typical Performance Curves - continued
2.0
10.0
VEN = 5.0V
9.0
1.8
EN Input
IENCurrent
[µA] : IEN [µA]
EN Threshold
: VEN [V]
VEN Voltage
[V]
VIN = 5.0V
Rising
1.6
1.4
1.2
8.0
7.0
6.0
5.0
4.0
3.0
Falling
2.0
1.0
1.0
0.8
0.0
-40
-20
0
20
40
60
80
-40
Temperature [℃]
[°C]
Temperature
0
20
40
60
80
Temperature[℃]
[°C]
Temperature
Figure 16. EN Threshold Voltage vs Temperature
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Figure 17. EN Input Current vs Temperature
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Typical Performance Curves (Application)
100
100
90
90
80
80
70
70
Efficiency [%]
Efficiency [%]
[%]
Efficiency
MODE = H
60
50
MODE = L
40
30
MODE = H
60
50
MODE = L
40
30
20
20
VIN = 5.0V
VOUT = 1.8V
10
VIN = 3.3V
VOUT = 1.8V
10
0
0
0.001
0.01
0.1
1
10
0.001
0.01
0.1
1
10
Output Current
IOUT [A]: IOUT [A]
Output Current
IOUT [A]: IOUT [A]
Figure 19. Efficiency vs Output Current
(VIN = 3.3V, VOUT = 1.8V, L = 1.5μH)
Figure 18. Efficiency vs Output Current
(VIN = 5V, VOUT = 1.8V, L = 1.5μH)
100
90
80
Efficiency
Efficiency [%]
[%]
70
VOUT = 1.2V
VOUT = 3.3V
60
VOUT = 1.8V
50
40
30
20
10
VIN = 5.0V
0
0
0.5
1
1.5
2
2.5
3
Output Current
IOUT [A] : IOUT [A]
Figure 20. Efficiency vs Output Current
(VIN = 5.0V, VMODE = 5.0V, L = 1.5μH)
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Typical Performance Curves (Application) - continued
VIN = 5V/div
VIN = 5V/div
VEN = 5V/div
VEN = 5V/div
VOUT = 1V/div
VOUT = 1V/div
VSW = 5V/div
Time = 1ms/div
VSW = 5V/div
Figure 22. Shutdown Waveform (VIN = VEN)
(VOUT = 1.8V, VMODE = VIN, RLOAD = 0.6Ω)
Figure 21. Start-up Waveform (VIN = VEN)
(VOUT = 1.8V, VMODE = VIN, RLOAD = 0.6Ω)
VIN = 5V/div
VIN = 5V/div
VEN = 5V/div
VEN = 5V/div
VOUT = 1V/div
VOUT = 1V/div
VSW = 5V/div
VSW = 5V/div
Time = 1ms/div
Figure 23. Start-up Waveform (VEN = 0V to 5V)
(VOUT = 1.8V, VMODE = VIN, RLOAD = 0.6Ω)
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Time = 1ms/div
Time = 1ms/div
Figure 24. Shutdown Waveform (VEN = 5V to 0V)
(VOUT = 1.8V, VMODE = VIN, RLOAD = 0.6Ω)
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Typical Performance Curves (Application) - continued
VOUT = 20mV/div
VOUT = 20mV/div
VSW = 2V/div
VSW = 2V/div
Time = 5ms/div
Time = 1µs/div
Figure 26. Output Voltage Ripple
(VIN = 5V, VOUT = 1.8V, VMODE = VIN, IOUT = 3A)
Figure 25. Output Voltage Ripple
(VIN = 5V, VOUT = 1.8V, VMODE = VIN, IOUT = 0A)
VIN = 50mV/div
VIN = 50mV/div
VSW = 2V/div
VSW = 2V/div
Time = 1µs/div
Time = 5ms/div
Figure 27. Input Voltage Ripple
(VIN = 5V, VOUT = 1.8V, VMODE = VIN, IOUT = 0A)
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Figure 28. Input Voltage Ripple
(VIN = 5V, VOUT = 1.8V, VMODE = VIN, IOUT = 3A)
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1.0
1.0
0.8
0.8
0.6
0.6
Output Voltage Deviation [%]
Output Voltage Deviation [%]
Typical Performance Curves (Application) - continued
0.4
0.2
0.0
-0.2
-0.4
-0.6
0.4
0.2
0.0
-0.2
-0.4
-0.6
-0.8
-0.8
-1.0
-1.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
0.0
VIN [V]
Input Voltage
: VIN [V]
0.5
1.0
1.5
2.0
2.5
3.0
Output Current
VIN [V]: IOUT [A]
Figure 29. Line Regulation
(VOUT = 1.8V, VMODE = VIN, IOUT=3A)
Figure 30. Load Regulation
(VIN = 5V, VOUT = 1.8V, VMODE = VIN)
VOUT = 50mV/div
VOUT = 50mV/div
IOUT = 1A/div
IOUT = 1A/div
Time = 1ms/div
Time = 1ms/div
Figure 31. Load Transient Response
IOUT = 0.75A - 2.25A
(VIN = 5V, VOUT = 1.8V, VMODE = VIN, COUT = 22μF x 2)
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Figure 32. Load Transient Response
IOUT = 0A - 3A
(VIN = 5V, VOUT = 1.8V, VMODE = VIN, COUT = 22μF x 2)
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BD9A302QWZ
Application Information
1.
Function Explanations
(1) Basic Operation
(a) DC/DC Converter Operation
BD9A302QWZ is a synchronous rectifying buck DC/DC converter that achieves fast load transient response
by employing current mode control system. It utilizes switching operation in PWM (Pulse Width Modulation)
mode for heavy load, while it utilizes SLLM (Simple Light Load Mode) control for light load to improve
efficiency.
Efficiency [%]
① SLLMTM Control
② PWM Control
Output Current : IOUT [A]
Figure 33. Efficiency (SLLMTM Control and PWM Control)
②PWM Control
①SLLMTM Control
VOUT = 50mV/div
VOUT = 50mV/div
VSW = 2V/div
VSW = 2V/div
Time = 2µs/div
Time = 2µs/div
Figure 34. SW Waveform (SLLMTM Control)
(VIN = 5.0V, VOUT = 1.8V, VMODE = VIN, IOUT = 50mA)
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Figure 35. SW Waveform (PWM Control)
(VIN = 5.0V, VOUT = 1.8V, VMODE = VIN, IOUT = 1A)
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BD9A302QWZ
(b) Enable Control
The IC shutdown can be controlled by the voltage applied to the EN terminal. When VEN reaches 2.0V (Min),
the internal circuit is activated and the IC starts up. To enable shutdown control with the EN terminal, the
shutdown interval (low level interval of EN) must be set to 100µs or longer. Startup by EN must be at the same
time or after the input of power supply voltage.
VEN
VENH
VENL
0
t
VOUT
0
t
Start-up
Shutdown
Figure 36. Start-up and Shutdown with Enable
(c) Soft Start
When EN terminal is switched High, Soft Start operates and the output voltage gradually rises. With the Soft
Start Function, overshoot of output voltage and rush current can be prevented. The rising time of output
voltage is 1ms (Typ).
EN
VOUT
0.8V x 90%
0.8V
FB
1ms(Typ)
Figure 37. Soft Start Timing Chart
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BD9A302QWZ
(2) Protection
The protective circuits are intended for prevention of damage caused by unexpected accidents.
Do not use them for continuous protective operation.
(a) Short Circuit Protection (SCP)
The short circuit protection block compares the FB terminal voltage with the internal reference voltage V REF.
When the FB terminal voltage has fallen below 0.4V (Typ) for 1ms (Typ), SCP stops the operation for 16ms
(Typ) and subsequently initiates a restart. However, during start-up, short circuit protection does not operate
even if the IC is still in the SCP condition.
EN Terminal
Start-up Condition
During start-up
2.0V or higher
Completed start-up
0.8V or lower
-
FB Terminal
Short Circuit Protection
≤ 0.4V (Typ)
OFF
> 0.4V (Typ)
OFF
≤ 0.4V (Typ)
ON
> 0.4V (Typ)
OFF
-
OFF
Soft start
1ms (Typ)
VOUT
SCP delay time
1ms (Typ)
SCP delay time
1ms (Typ)
0.8V
FB
SCP threshold voltage:
0.4V (Typ)
SCP release
High side
FET gate
Low
Low side
FET gate
Low
OCP
threshold
6.0A (Typ)
Inductor Current
(Output Current)
Build-in
IC HICCUP
Delay Signal
16ms (Typ)
SCP reset
Figure 38. Short Circuit Protection (SCP) Timing Chart
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BD9A302QWZ
(b) Under Voltage Lockout Protection (UVLO)
The Under Voltage Lockout Protection circuit monitors the VIN terminal voltage. The operation enters standby
when the VIN terminal voltage is 2.45V (Typ) or lower. The operation starts when the VIN terminal voltage is
2.55V (Typ) or higher.
VIN
UVLO Release
Hysteresis
UVLO Detection
0V
VOUT
Soft Start
FB
High side
FET gate
Low side
FET gate
Normal operation
UVLO
Normal operation
Figure 39. UVLO Timing Chart
(c) Thermal Shutdown (TSD)
When the chip temperature exceeds Tj = 175C (Typ), the DC/DC converter output is stopped. Thermal
protection circuit is reset when the temperature falls down. The thermal shutdown circuit is intended for
shutting down the IC from thermal runaway in an abnormal state with the temperature exceeding Tjmax =
150C. It is not meant to protect or guarantee the reliability of the application. Do not use this function of the
circuit for application protection design.
(d) Over Current Protection (OCP)
The Over Current Protection function operates by using the current mode control to limit the current that flows
through the high-side MOSFET at each cycle of the switching frequency. The designed over current limit value
is 6.0A (Typ).
(e) Over Voltage Protection (OVP)
The over voltage protection function (OVP) compares the FB terminal voltage with the internal reference
voltage VREF. When the FB terminal voltage exceeds 0.88V (Typ), it turns the output MOSFETs off. The output
voltage returns to normal operation level with hysteresis after the output voltage drops.
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BD9A302QWZ
2.
Application Example (VOUT=3.3V)
Parameter
Input Voltage
Output Voltage
Switching Frequency
Maximum Output Current
Operating Temperature Range
Symbol
Value
VIN
5V
VOUT
3.3V
fOSC
1MHz (Typ)
IOUTMAX
3A
Topr
-40°C to +85°C
BD9A302QWZ
VIN
C3
C2
1
VIN
GND
8
2
EN
FB
7
3
BST
ITH
6
4
SW
MODE
5
C1
EN
C8
VOUT
L1
R0
C6
C10
MODE
C5
R3
C9
R2
VIN
R1
Figure 40. Application Circuit
Table 1. Recommended Component Values
Part No.
Value
Company
Part Name
FDSD0420-H-1R5M
L1
1.5μH
Murata
(Note 1)
0.1μF
Murata
GRM155B11A104MA01
C2 (Note 2)
10μF
Murata
GRM21BB31A106ME18
C3
-
-
-
C1
C5
(Note 3)
22μF
Murata
GRM21BB30J226ME38
C6
(Note 3)
22μF
Murata
GRM21BB30J226ME38
C8 (Note 4)
0.1μF
Murata
GRM155B11A104MA01
C9
2700pF
Murata
GRM155B11H272KA01
C10
-
-
-
R0
0Ω
ROHM
MCR01MZPJ000
R1
24kΩ
ROHM
MCR01MZPD2402
R2
75kΩ
ROHM
MCR01MZPD7502
R3
18kΩ
ROHM
MCR01MZPD1802
(Note 1) In order to reduce the influence of high frequency noise, mount the 0.1μF ceramic capacitor as close as possible to the VIN pin and GND pin.
(Note 2) For the capacitance of input capacitor, take temperature characteristics, DC bias characteristics, etc. into consideration to set to a minimum
value of no less than 4.7μF.
(Note 3) In case capacitance value fluctuates due to temperature characteristics, DC bias characteristics, etc. of output capacitor, loop response
characteristics may change. Please confirm on actual equipment. When selecting a capacitor, confirm the characteristics of the capacitor in its
datasheet. Ceramic type of capacitors is recommended for the output capacitors.
(Note 4) For capacitance of bootstrap capacitor take temperature characteristics, DC bias characteristics, etc. into consideration to set minimum value
to no less than 0.047μF.
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BD9A302QWZ
100
180
80
MODE = H
90
PHASE
60
135
80
40
90
20
45
0
0
50
MODE = L
40
-20
-45
GAIN
30
-90
-40
20
VIN = 5.0V
VOUT = 3.3V
10
Phase Margin
69.8deg
-60
-135
-180
-80
0
0.001
0.01
0.1
1
10
10
1
100
1000
Frequency [kHz]
Output Current : IOUT [A]
Figure 42. Closed Loop Response IOUT = 1A
(VIN = 5V, VOUT = 3.3V, L = 1.5μH, COUT = 22μF x 2)
Figure 41. Efficiency vs Output Current
(VIN = 5V, VOUT = 3.3V, L = 1.5μH)
VOUT = 100mV/div
VOUT = 50mV/div
VSW = 2V/div
IOUT = 1A/div
Time = 2μs/div
Time = 1ms/div
Figure 43. Load Transient Response
IOUT = 0.75A – 2.25A
(VIN = 5V, VOUT = 3.3V, L = 1.5μH, COUT = 22μF x 2)
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Figure 44. VOUT Ripple IOUT = 3A
(VIN = 5V, VOUT = 3.3V, L = 1.5μH, COUT=22μF x 2)
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Phase [°]
60
Gain [dB]
Efficiency [%]
70
BD9A302QWZ
3.
Application Example (VOUT=1.8V)
Parameter
Input Voltage
Output Voltage
Switching Frequency
Maximum Output Current
Operating Temperature Range
Symbol
Value
VIN
5V
VOUT
1.8V
fOSC
1MHz (Typ)
IOUTMAX
3A
Topr
-40°C to +85°C
BD9A302QWZ
VIN
C3
C2
1
VIN
GND
8
2
EN
FB
7
3
BST
ITH
6
4
SW
MODE
5
C1
EN
C8
VOUT
L1
R0
C6
C10
MODE
C5
R3
C9
R2
VIN
R1
Figure 45. Application Circuit
Table 2. Recommended Component Values
Part No.
Value
Company
Part Name
FDSD0420-H-1R5M
L1
1.5μH
Murata
(Note 1)
0.1μF
Murata
GRM155B11A104MA01
C2 (Note 2)
10μF
Murata
GRM21BB31A106ME18
C3
-
-
-
C1
C5
(Note 3)
22μF
Murata
GRM21BB30J226ME38
C6
(Note 3)
22μF
Murata
GRM21BB30J226ME38
C8 (Note 4)
0.1μF
Murata
GRM155B11A104MA01
C9
2700pF
Murata
GRM155B11H272KA01
C10
-
-
-
R0
0Ω
ROHM
MCR01MZPJ000
R1
24kΩ
ROHM
MCR01MZPD2402
R2
30kΩ
ROHM
MCR01MZPD3002
R3
9.1kΩ
ROHM
MCR01MZPD9101
(Note 1) In order to reduce the influence of high frequency noise, mount the 0.1μF ceramic capacitor as close as possible to the VIN pin and GND pin.
(Note 2) For the capacitance of input capacitor, take temperature characteristics, DC bias characteristics, etc. into consideration to set to a minimum
value of no less than 4.7μF.
(Note 3) In case capacitance value fluctuates due to temperature characteristics, DC bias characteristics, etc. of output capacitor, loop response
characteristics may change. Please confirm on actual equipment. When selecting a capacitor, confirm the characteristics of the capacitor in its
datasheet. Ceramic type of capacitors is recommended for the output capacitors.
(Note 4) For capacitance of bootstrap capacitor take temperature characteristics, DC bias characteristics, etc. into consideration to set minimum value
to no less than 0.047μF.
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BD9A302QWZ
100
80
180
MODE = H
90
60
135
PHASE
80
40
90
20
45
0
0
50
MODE = L
40
-20
-45
GAIN
30
-40
-90
20
VIN = 5.0V
VOUT = 1.8V
10
Phase Margin
70.6deg
-60
0
-135
-80
0.001
0.01
0.1
1
10
-180
1
10
Output Current
IOUT [A] : IOUT [A]
100
1000
Frequency [kHz]
Figure 47. Closed Loop Response IOUT = 1A
(VIN = 5V, VOUT = 1.8V, L = 1.5μH, COUT = 22μF x 2)
Figure 46. Efficiency vs Output Current
(VIN = 5V, VOUT = 1.8V, L = 1.5μH)
VOUT = 100mV/div
VOUT = 50mV/div
VSW = 2V/div
IOUT = 1A/div
Time = 2μs/div
Time = 1ms/div
Figure 48. Load Transient Response
IOUT = 0.75A – 2.25A
(VIN = 5V, VOUT = 1.8V, L = 1.5μH, COUT = 22μF x 2)
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Figure 49. VOUT Ripple IOUT = 3A
(VIN = 5V, VOUT = 1.8V, L = 1.5μH, COUT = 22μF x 2)
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Phase [°]
60
Gain [dB]
Efficiency [%]
70
BD9A302QWZ
4.
Application Example (VOUT=1.5V)
Parameter
Input Voltage
Output Voltage
Switching Frequency
Maximum Output Current
Operating Temperature Range
Symbol
Value
VIN
5V
VOUT
1.5V
fOSC
1MHz (Typ)
IOUTMAX
3A
Topr
-40°C to +85°C
BD9A302QWZ
VIN
C3
C2
1
VIN
GND
8
2
EN
FB
7
3
BST
ITH
6
4
SW
MODE
5
C1
EN
C8
VOUT
L1
R0
C6
C10
MODE
C5
R3
C9
R2
VIN
R1
Figure 50. Application Circuit
Table 3. Recommended Component Values
Part No.
Value
Company
Part Name
FDSD0420-H-1R5M
L1
1.5μH
Murata
(Note 1)
0.1μF
Murata
GRM155B11A104MA01
C2 (Note 2)
10μF
Murata
GRM21BB31A106ME18
C3
-
-
-
C1
C5
(Note 3)
22μF
Murata
GRM21BB30J226ME38
C6
(Note 3)
22μF
Murata
GRM21BB30J226ME38
C8 (Note 4)
0.1μF
Murata
GRM155B11A104MA01
C9
2700pF
Murata
GRM155B11H272KA01
C10
-
-
-
R0
0Ω
ROHM
MCR01MZPJ000
R1
18kΩ
ROHM
MCR01MZPD1802
R2
16kΩ
ROHM
MCR01MZPD1602
R3
9.1kΩ
ROHM
MCR01MZPD9101
(Note 1) In order to reduce the influence of high frequency noise, mount the 0.1μF ceramic capacitor as close as possible to the VIN pin and GND pin.
(Note 2) For the capacitance of input capacitor, take temperature characteristics, DC bias characteristics, etc. into consideration to set to a minimum
value of no less than 4.7μF.
(Note 3) In case capacitance value fluctuates due to temperature characteristics, DC bias characteristics, etc. of output capacitor, loop response
characteristics may change. Please confirm on actual equipment. When selecting a capacitor, confirm the characteristics of the capacitor in its
datasheet. Ceramic type of capacitors is recommended for the output capacitors.
(Note 4) For capacitance of bootstrap capacitor take temperature characteristics, DC bias characteristics, etc. into consideration to set minimum value
to no less than 0.047μF.
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BD9A302QWZ
100
80
180
MODE = H
90
60
135
PHASE
80
40
90
20
45
0
0
50
MODE = L
40
-20
-45
GAIN
30
-40
-90
20
VIN = 5.0V
VOUT = 1.5V
10
Phase Margin
68.1deg
-60
-135
-80
0
0.001
0.01
0.1
1
10
-180
1
10
100
1000
Frequency [kHz]
Output Current
: IOUT [A]
IOUT [A]
Figure 52. Closed Loop Response IOUT = 1A
(VIN = 5V, VOUT = 1.5V, L = 1.5μH, COUT = 22μF x 2)
Figure 51. Efficiency vs Output Current
(VIN = 5V, VOUT = 1.5V, L = 1.5μH)
VOUT = 100mV/div
VOUT = 50mV/div
VSW = 2V/div
IOUT = 1A/div
Time = 1ms/div
Time = 2μs/div
Figure 53. Load Transient Response
IOUT=0.75A – 2.25A
(VIN = 5V, VOUT = 1.5V, L = 1.5μH, COUT = 22μF x 2)
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Figure 54. VOUT Ripple IOUT = 3A
(VIN = 5V, VOUT = 1.5V, L = 1.5μH, COUT = 22μF x 2)
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Phase [°]
60
Gain [dB]
Efficiency [%]
70
BD9A302QWZ
5.
Application Example (VOUT=1.2V)
Parameter
Input Voltage
Output Voltage
Switching Frequency
Maximum Output Current
Operating Temperature Range
Symbol
Value
VIN
5V
VOUT
1.2V
fOSC
1MHz (Typ)
IOUTMAX
3A
Topr
-40°C to +85°C
BD9A302QWZ
VIN
C3
C2
1
VIN
GND
8
2
EN
FB
7
3
BST
ITH
6
4
SW
MODE
5
C1
EN
C8
VOUT
L1
R0
C6
C10
MODE
C5
R3
C9
R2
VIN
R1
Figure 55. Application Circuit
Table 4. Recommended Component Values
Part No.
Value
Company
Part Name
FDSD0420-H-1R5M
L1
1.5μH
Murata
(Note 1)
0.1μF
Murata
GRM155B11A104MA01
C2 (Note 2)
10μF
Murata
GRM21BB31A106ME18
C3
-
-
-
C1
C5
(Note 3)
22μF
Murata
GRM21BB30J226ME38
C6
(Note 3)
22μF
Murata
GRM21BB30J226ME38
C8 (Note 4)
0.1μF
Murata
GRM155B11A104MA01
C9
2700pF
Murata
GRM155B11H272KA01
C10
-
-
-
R0
0Ω
ROHM
MCR01MZPJ000
R1
20kΩ
ROHM
MCR01MZPD2002
R2
10kΩ
ROHM
MCR01MZPD1002
R3
8.2kΩ
ROHM
MCR01MZPD8201
(Note 1) In order to reduce the influence of high frequency noise, mount the 0.1μF ceramic capacitor as close as possible to the VIN pin and GND pin.
(Note 2) For the capacitance of input capacitor, take temperature characteristics, DC bias characteristics, etc. into consideration to set to a minimum
value of no less than 4.7μF.
(Note 3) In case capacitance value fluctuates due to temperature characteristics, DC bias characteristics, etc. of output capacitor, loop response
characteristics may change. Please confirm on actual equipment. When selecting a capacitor, confirm the characteristics of the capacitor in its
datasheet. Ceramic type of capacitors is recommended for the output capacitors.
(Note 4) For capacitance of bootstrap capacitor take temperature characteristics, DC bias characteristics, etc. into consideration to set minimum value
to no less than 0.047μF.
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BD9A302QWZ
100
180
80
MODE = H
90
PHASE
60
135
60
Gain [dB]
Efficiency [%]
70
50
MODE = L
40
40
90
20
45
0
0
-20
-45
GAIN
30
-90
-40
20
VIN = 5.0V
VOUT = 1.2V
10
Phase Margin
64.7deg
-60
-135
-180
-80
0
0.001
0.01
0.1
1
10
1
10
100
1000
Output Current
IOUT [A]: IOUT [A]
Frequency [kHz]
Figure 56. Efficiency vs Output Current
(VIN = 5V, VOUT = 1.2V, L = 1.5μH)
Figure 57. Closed Loop Response IOUT = 1A
(VIN = 5V, VOUT = 1.2V, L = 1.5μH, COUT = 22μF x 2)
VOUT = 100mV/div
VOUT = 50mV/div
VSW = 2V/div
IOUT = 1A/div
Time = 1ms/div
Time = 2μs/div
Figure 58. Load Transient Response
IOUT = 0.75A – 2.25A
(VIN = 5V, VOUT = 1.2V, L = 1.5μH, COUT = 22μF x 2)
Figure 59. VOUT Ripple IOUT = 3A
(VIN = 5V, VOUT = 1.2V, L = 1.5μH, COUT = 22μF x 2)
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Phase [°]
80
BD9A302QWZ
6.
Selection of Components Externally Connected
About the application except the recommendation, please contact us.
(1) Output LC Filter Constant
The DC/DC converter requires an LC filter for smoothing the output voltage in order to supply a continuous current
to the load. ∆IL ripple current flowing through the inductor is returned to the BD9A302QWZ for SLLMTM control. It is
recommended to use 1.5µH inductor since the feedback current has the best behavior in the specified inductance
value.
VIN
IL
Inductor Saturation Current > IOUTMAX + ΔIL / 2
ΔIL
L
IOUT
VOUT
Driver
COUT
Average Inductor Current
t
Figure 60. Waveform of Inductor Current
Figure 61. Output LC Filter Circuit
Calculation with VIN = 5V, VOUT = 1.8V, L=1.5µH, and switching frequency fOSC = 1MHz is expressed as below.
Inductor ripple current ∆IL
ΔI L =V OUT × (V IN -V OUT ) ×
1
= 768 mA
V IN × f OSC × L
The saturation current of the inductor must be larger than the sum of the maximum output current and one-half
(1/2) of the inductor ripple current ∆IL.
The output capacitor COUT affects the output ripple voltage characteristics. The output capacitor COUT must satisfy
the required ripple voltage characteristics.
The output ripple voltage can be represented by the following equation.
ΔV RPL = ΔI L × (R ESR +
1
) V
8 × C OUT × f OSC
RESR is the Equivalent Series Resistance (ESR) of the output capacitor.
Be careful of the total capacitance value, when additional capacitor CLOAD is connected to the output capacitor
COUT. Use maximum additional capacitor CLOAD (Max) condition which satisfies the following method.
Maximumstarting inductor ripple current I LSTART < Over Current limit 3.8 A (Min)
Maximum starting inductor ripple current ILSTART can be expressed in the following method.
I LSTART = Maximum starting output current(I OUTMAX ) + Charge current to output capacitor( I CAP ) +
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BD9A302QWZ
Charge current of the output capacitor ICAP can be expressed in the following method.
I CAP =
(C OUT + C LOAD ) × V OUT
A
t SS
Calculation with VIN= 5V, VOUT= 3.3V, L= 1.5µH, switching frequency fOSC= 800kHz(Min), output capacitor COUT=
44µF, Soft Start time tSS= 0.5ms(Min), load current during soft start IOSS= 2A is expressed as below.
C LOAD(Max) <
(3.8 - I OSS - ΔI L /2) × t SS
- C OUT 157.9 μF
V OUT
(Note) CLOAD has an effect on the stability of the DC/DC converter.
To ensure the stability of the DC/DC converter, make sure that a sufficient phase margin is provided.
(2) Output Voltage Setting
The output voltage value is set by the feedback resistance ratio.
VOUT
R2
Error Amplifier
FB
－
R1
＋
0.8V
VOUT = R1+R2 × 0.8 V
R1
Figure 62. Feedback Resistors
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(3) Phase Compensation Component
A current mode control buck DC/DC converter is a one-pole, one-zero system. One-pole is formed by an error
amplifier and load and the one-zero point is added by phase compensation. The phase compensation resistor R ITH
determines the crossover frequency fCRS where the total loop gain of the DC/DC converter is 0dB. A high value
crossover frequency fCRS provides a good load transient response characteristic but inferior stability. Conversely, a
low value crossover frequency fCRS greatly stabilizes the characteristics but the load transient response
characteristic is impaired.
(a) Selection of Phase Compensation Resistor RITH
The Phase Compensation Resistance RITH can be determined by using the following equation.
RITH = 2π ×VOUT × f CRS × C OUT Ω
V FB ×G MP×GMA
Where:
VOUT is the output voltage [V]
fCRS is the crossover frequency [Hz]
COUT is the output capacitance [F]
VFB is the feedback reference voltage (0.8V (Typ))
GMP is the current sense gain (13A/V (Typ))
GMA is the error amplifier transconductance (260µA/V (Typ))
(b) Selection of Phase Compensation Capacitance CITH
For stable operation of the DC/DC converter, zero for compensation cancels the phase delay due to the pole
formed by the load.
The phase compensation capacitance CITH can be determined by using the following equation.
C ITH = C OUT ×VOUT F
RITH × I OUT
(c) Loop Stability
To ensure the stability of the DC/DC converter, make sure that a sufficient phase margin is provided. A phase
margin of at least 45º in the worst conditions is recommended.
VOUT
A
(a)
Gain [dB]
R2
FB
R1
－
ITH
GBW(b)
【dB】
0
＋
RITH
0.8V
CITH
Phase
【°】
Phase[deg]
－90
－90°
PHASE MARGIN
－180°
－180
f
Figure 63. Phase Compensation Circuit
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f
fCRS
0
Figure 64. Bode Plot
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7. PCB Layout Design
Figure 65 shows a buck DC/DC converter with a large pulsing current flowing into two loops. The first loop is the
current flows to the converter when the high-side FET is turned on. The flow starts from the input capacitor CIN, runs
through the FET, inductor L and the output capacitor COUT, back to GND of CIN via GND of COUT. The second loop is the
current flows when the low-side FET is turned on. The flow starts from the low-side FET, runs through the inductor L
and output capacitor COUT, back to GND of the low-side FET via GND of COUT. Route these two loops as thick and as
short as possible to reduce noise for improved efficiency. It is recommended to connect the input and output capacitors
directly to the GND plane. The PCB layout has a great influence on the DC/DC converter in terms of the overall heat
generation, noise and efficiency characteristics.
VIN
VOUT
L
MOS FETs
CIN
COUT
GND
Figure 65. Current Loop of Buck DC/DC Converter
Accordingly, design the PCB layout considering the following points:
(1) Connect an input capacitor as close as possible to the IC VIN terminal and GND terminal on the same plane as
the IC.
(2) If there is any unused area on the PCB, provide a copper foil plane for the GND node to assist heat dissipation
from the IC and the surrounding components.
(3) Switching nodes such as SW are susceptible to noise due to AC coupling with the other nodes. Route the inductor
pattern as thick and as short as possible.
(4) Provide lines connected to FB and ITH terminal with considerable distance from the SW nodes.
(5) Place the output capacitor away from the input capacitor to avoid the propagation of harmonic noise from the
input.
Feedback
Resistors
VIN
MODE
SW
FB
GND
ITH
BST
Input Bulk
Capacitor
(10μF)
EN
VIN
Input Bypass
Capacitor
(0.1μF)
GND
Output Capacitor
Output Inductor
Backside Heat Dissipation
Exposed Pad
Enable Control
VOUT
Bootstrap
Capacitor
Signal VIA
Thermal VIA
Bottom Layer Line
Figure 66. PCB Layout (MODE = H)
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I/O Equivalence Circuits
2. EN
3. BST / 4. SW
VIN
BST
VIN
EN
430kΩ
10kΩ
SW
570kΩ
GND
VIN
GND
GND
GND
5. MODE
6. ITH
VIN
MODE
10Ω
40Ω
10kΩ
ITH
500kΩ
GND
GND
GND
GND
7. FB
20kΩ
FB
20kΩ
GND
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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. Separate the ground and supply lines of the
digital and analog blocks to prevent noise in the ground and supply lines of the digital block from affecting the analog
block. 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.
Thermal Consideration
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, increase the
board size and copper area to prevent exceeding the maximum junction temperature rating.
6.
Recommended Operating Conditions
These conditions represent a range within which the expected characteristics of the IC can be approximately obtained.
The electrical characteristics are guaranteed under the conditions of each parameter.
7.
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.
8.
Operation Under Strong Electromagnetic Field
Operating the IC in the presence of a strong electromagnetic field may cause the IC to malfunction.
9.
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.
10. 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.
11. Unused Input Terminals
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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Operational Notes – continued
12. Regarding Input Pins 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 67. Example of Monolithic IC Structure
13. 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.
14. Area of Safe Operation (ASO)
Operate the IC such that the output voltage, output current, and the maximum junction temperature rating are all within
the Area of Safe Operation (ASO).
15. 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 all 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.
16. 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.
17. Disturbance Light
In a device where a portion of silicon is exposed to light such as in a WL-CSP, IC characteristics may be affected due
to photoelectric effect. For this reason, it is recommended to come up with countermeasures that will prevent the chip
from being exposed to light.
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Ordering Information
B
D
9
A
3
Part Number
0
2
Q
W
Z
Package
UMMP008AZ020
-
E2
Packaging and forming specification
E2: Embossed tape and reel
Marking Diagram
UMMP008AZ020 (TOP VIEW)
Part Number Marking
D9A
LOT Number
3 0 2
1PIN MARK
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Physical Dimension, Tape and Reel Information
Package Name
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UMMP008AZ020
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Revision History
Date
Revision
14.Mar.2017
001
Changes
New Release
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Notice
Precaution on using ROHM Products
1.
Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
(Note 1)
intend to use our Products in devices requiring extremely high reliability (such as medical equipment
, transport
equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car
accessories, safety devices, 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 designed and manufactured for use under standard conditions and not 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-PGA-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-PGA-E
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.003
Datasheet
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3.
The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or
concerning such information.
Notice – WE
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.001
