BD8962MUVE2 [ROHM]
Synchronous Buck Converter with Integrated FET;
| 型号： | BD8962MUVE2 |
| 厂家： | 
ROHM |
| 描述： | Synchronous Buck Converter with Integrated FET |
| 文件： | 总26页 (文件大小：1923K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Datasheet
2.7V to 5.5V, 3A 1ch
Synchronous Buck Converter with
Integrated FET
BD8962MUV
General Description
Key Specifications
The BD8962MUV is ROHM's high efficiency step-down
switching regulator designed to produce a voltage as
low as 0.8V from a supply voltage of 5.5V/3.3V. It offers
high efficiency by using synchronous switches and
provides fast transient response to sudden load
changes by implementing current mode control.
Input Voltage Range:
Output Voltage Range:
Average Output Current:
Switching Frequency:
2.7V to 5.5V
0.8V to 2.5V
3.0A(Max)
1MHz(Typ)
82mΩ(Typ)
70mΩ(Typ)
High Side FET ON-Resistance:
Low Side FET ON-Resistance:
Standby Current:
0μA(Typ)
Operating Temperature Range:
-40°C to +105°C
Features
Fast Transient Response because of Current Mode
Control System
Packages
W(Typ) x D(Typ) x H(Max)
High Efficiency for all Load Ranges because of
Synchronous Switches
Soft-Start Function
Thermal Shutdown and UVLO Functions
Short Circuit Protection with Time Delay Function
Shutdown Function
Applications
Power Supply for LSI including DSP, Microcomputer
and ASIC
VQFN020V4040
4.00mm x 4.00mm x 1.00mm
Typical Application Circuit
C1
Rf
VCC
CIN
PVCC
VCC
EN
CBST
ADJ
L
VOUT
ITH
SW
GND, PGND
RITH
CITH
CO
R2
R1
Figure 1. Typical Application Circuit
○Product structure：Silicon monolithic integrated circuit ○ This product has no designed protection against radioactive rays
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Datasheet
BD8962MUV
Pin Configuration
(TOP VIEW)
ADJ
ITH GND
15 14 13 12 11
N.C.
16
17
18
19
20
N.C.
EN
10
9
VCC
BST
8
PGND
7
6
PVCC
1
2
3
4
5
SW
Figure 2. Pin Configuration
Pin Description
Pin
No.
1
Pin
Name
SW
Pin
No.
11
Pin
Name
GND
ADJ
Function
Function
Power switch node
Power switch node
Ground pin
2
SW
12
Output voltage detection pin
GmAmp output pin/Connected to phase
compensation capacitor
No connection
3
SW
Power switch node
13
ITH
4
5
SW
SW
Power switch node
Power switch node
14
15
16
17
18
N.C.
N.C.
N.C.
EN
No connection
6
PVCC Power switch supply pin
PVCC Power switch supply pin
PVCC Power switch supply pin
No connection
7
Enable pin(Active High）
8
PGND Power switch ground pin
PGND Power switch ground pin
PGND Power switch ground pin
9
BST
VCC
Bootstrapped voltage input pin
Power supply input pin
19
20
10
Block Diagram
VCC
PVCC
PVCC
VCC
2/22
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Datasheet
BD8962MUV
Absolute Maximum Ratings(Ta=25°C)
Parameter
Symbol
Rating
-0.3 to +7 (Note 1)
-0.3 to +7 (Note 1)
-0.3 to +13
-0.3 to +7
Unit
V
VCC
PVCC
VBST
VCC Voltage
V
PVCC Voltage
V
BST Voltage
VBST-SW
VEN
V
BST_SW Voltage
-0.3 to +7
V
EN Voltage
VSW, VITH
Pd1
-0.3 to +7
V
SW,ITH Voltage
0.34 (Note 2)
0.70 (Note 3)
1.21 (Note 4)
3.56 (Note 5)
-40 to +105
-55 to +150
+150
W
W
W
W
°C
°C
°C
Power Dissipation 1
Power Dissipation 2
Power Dissipation 3
Power Dissipation 4
Operating Temperature Range
Storage Temperature Range
Maximum Junction Temperature
Pd2
Pd3
Pd4
Topr
Tstg
Tjmax
(Note 1)
(Note 2)
(Note 3)
(Note 4)
(Note 5)
Pd should not be exceeded.
IC only
Mounted on a 1-layer 74.2mmx74.2mmx1.6mm glass-epoxy board, occupied copper foil area : 10.29mm2
Mounted on a 4-layer 74.2mmx74.2mmx1.6mm glass-epoxy board, occupied copper foil area: 10.29mm2 in each layer
Mounted on a 4-layer 74.2mmx74.2mmx1.6mm glass-epoxy board, occupied copper foil area : 5505mm2in each layer
Caution: 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.
Recommended Operating Conditions (Ta=-40°C to +105°C)
Limit
Unit
Parameter
Symbol
Min
2.7
2.7
0
0.8
-
Typ
3.3
3.3
-
-
-
Max
5.5
5.5
VCC
PVCC
VEN
VOUT
ISW
V
V
V
V
A
Power Supply Voltage
EN Voltage
5.5
2.5 (Note 6)
3.0 (Note 7)
Output Voltage Setting Range
SW Average Output Current
(Note 6)
(Note 7)
In case of setting the output voltage to 1.6V or more, VCCMin = VOUT+1.2V.
Pd should not be exceeded.
Electrical Characteristics(Ta=25°C VCC=PVCC=3.3V, VEN=VCC, R1=10kΩ, R2=5kΩ ,unless otherwise specified.)
Limit
Typ
0
250
GND
VCC
1
1
82
Parameter
Symbol
Unit
Conditions
Min
-
-
Max
10
500
0.8
-
Standby Current
Active Current
EN Low Voltage
EN High Voltage
ISTB
ICC
VENL
VENH
IEN
µA
µA
V
EN=GND
VCC current
Standby mode
Active mode
-
2.0
-
0.8
-
V
EN Input Current
10
µA
MHz
mΩ
mΩ
V
µA
µA
V
VEN=3.3V
Oscillation Frequency
High Side FET ON-Resistance
Low Side FET ON-Resistance
ADJ Voltage
fOSC
1.2
115
98
0.812
-
RONH
RONL
VADJ
ITHSI
ITHSO
VUVLO1
VUVLO2
tSS
PVCC=3.3V
PVCC=3.3V
-
70
0.800
18
0.788
10
10
2.400
2.425
2.5
0.5
ITH SInk Current
VADJ=1V
VADJ=0.6V
VCC=3.3V to 0V
VCC=0V to 3.3V
ITH Source Current
UVLO Threshold Voltage
UVLO Release Voltage
Soft Start Time
18
-
2.500
2.550
5
2.600
2.700
10
V
ms
ms
Timer Latch Time
tLATCH
1
2
Output Short Circuit
Threshold Voltage
VSCP
-
0.40
0.56
V
VADJ =0.8V to 0V
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Datasheet
BD8962MUV
Typical Performance Curves
[VOUT=1.2V]
[VOUT=1.2V]
VCC=5V
Ta=25°C
IO=0A
Ta=25°C
IO=3A
Input Voltage: VCC[V]
EN Voltage : VEN[V]
Figure 4. Output Voltage vs Input Voltage
Figure 5. Output Voltage vs EN Voltage
[VOUT=1.2V]
[VOUT=1.2V]
VCC=5V
IO=0A
VCC=5V
Ta=25°C
Output Current: IOUT[A]
Temperature: Ta[°C]
Figure 6. Output Voltage vs Output Current
Figure 7. Output Voltage vs Temperature
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BD8962MUV
Typical Performance Curves - continued
[VOUT=1.2]
VCC=5V
Ta=25°C
VCC=5V
Output Current : IOUT[mA]
Temperature: Ta[°C]
Figure 9. Frequency vs Temperature
Figure 8. Efficiency vs Output Current
High Side
Low Side
VCC=3.3V
VCC=5V
Temperature: Ta[°C]
Temperature : Ta[°C]
Figure 11. EN Voltage vs Temperature
Figure 10. ON-Resistance vs Temperature
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Datasheet
BD8962MUV
Typical Performance Curves – continued
VCC=5V
Ta=25°C
Input Voltage : VCC[V]
Temperature: Ta[°C]
Figure 13. Frequency vs Input Voltage
Figure 12. Circuit Current vs Temperature
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BD8962MUV
Typical Waveforms
[VOUT=1.2V]
[PWM
SW
[VOUT=1.2V]
VCC=PVCC
=EN
VOUT
VCC=5V
Ta=25°C
IO=0A
VOUT
VCC=5V
Ta=25°C
Figure 14. Soft Start Waveform
Figure 15. SW Waveform
(Io=10mA)
[VOUT=1.2V]
VOUT
[VOUT=1.2V]
VOUT
IOUT
IOUT
VCC=5V
VCC=5V
Ta=25°C
Ta=25°C
Figure 16. Transient Response
(Io=1A to 3A, 10µs)
Figure 17. Transient Response
(Io=3A to 1A, 10µs)
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Datasheet
BD8962MUV
Application Information
1. Operation
BD8962MUV is a synchronous step-down switching regulator that achieves fast transient response by employing current
mode PWM control system.
(1) Synchronous Rectifier
Integrated synchronous rectification using two MOSFETs reduces power dissipation and increases efficiency when
compared to converters using external diodes. Internal shoot-through current limiting circuit further reduces power
dissipation.
(2) Current Mode PWM Control
PWM control signal of this IC depends on two feedback loops, the voltage feedback and the inductor current
feedback.
(a) PWM (Pulse Width Modulation) control
The clock signal coming from OSC has a frequency of 1MHz. When OSC sets the RS latch, the P-Channel
MOSFET is turned ON and the N-Channel MOSFET is turned OFF. The opposite happens when the current
comparator (Current Comp) resets the RS latch i.e. the P-Channel MOSFET is turned OFF and the N-Channel
MOSFET is turned ON. Current Comp's output is a comparison of two signals, the current feedback control
signal "SENSE" which is a voltage proportional to the current IL, and the voltage feedback control signal, FB.
SENSE
Current
Comp
VOUT
RESET
R
S
Q
IL
Level
Shift
FB
SET
Driver
Logic
VOUT
Gm Amp
SW
Load
OSC
RITH
Figure 18. Diagram of Current Mode PWM Control
PVCC
Current
Comp
SENSE
FB
SET
GND
GND
GND
RESET
SW
IL
IL(AVE)
VOUT
VOUT(AVE)
Figure 19. PWM Switching Timing Chart
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BD8962MUV
2. Description of Operations
(1) Soft-Start Function
During start-up, the soft-start circuit gradually establishes the output voltage to limit the input current. This prevents
the overshoot in the output voltage and inrush current.
(2) Shutdown Function
When the EN terminal is shifted to “Low”, the device operates in Standby Mode, and all the functional blocks
including the reference voltage circuit, internal oscillator and drivers are turned OFF. Circuit current during standby is
0µA (Typ).
(3) UVLO Function
The UVLO circuit detects whether the input voltage is sufficient to obtain the output voltage of this IC. A hysteresis
width of 50mV (Typ) is provided to prevent the output from chattering.
Hysteresis 50mV
VCC
EN
VOUT
tss
tss
tss
Soft Start
Standby
Mode
Standby
Mode
Standby Mode
Operating Mode
Operating Mode
Operating Mode
Standby Mode
UVLO
EN
UVLO
UVLO
Figure 20. Soft Start, Shutdown, UVLO Timing Chart
(4) Short Circuit Protection with Time Delay Function
To protect the IC from breakdown, the short circuit protection turns the output OFF when the internal circuit limiter is
activated continuously for a fixed time (tLATCH) or more. The output that is kept OFF may be turned ON again by
restarting EN or by resetting UVLO.
EN
1msec
VOUT
1/2VOUT
Output Current in non-control
Until output voltage goes up to half of Vo or over,
timer latch is not operated.
(No timer latch, only limit to the output current)
Limit
Output voltage OFF Latch
IL
Output Current controlled by limit value
(Limit value changes in proportion to output voltage)
Standby Mode
Operated Mode
Standby Mode
Operated Mode
EN
Timer Latch
EN
Figure 21. Short Current Protection Circuit with Time Delay Timing Chart
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BD8962MUV
3. Information on Advantages
Advantage 1：Offers fast transient response by using current mode control system
BD8962MUV (Load response IO=1A to 3A)
Conventional product (Load response IO=1A to 3A)
VOUT
VOUT
62mV
145mV
IOUT
IOUT
Voltage drop due to sudden change in load was reduced by about 50%.
Figure 22. Comparison of Transient Response
Advantage 2： Offers high efficiency for all load range because of its synchronous rectifier
100
【VOUT=1.2】
For heavier load:
90
80
70
60
50
40
30
20
10
0
This IC utilizes the synchronous rectifying mode and uses low ON-Resistance
MOSFET power transistors.
ON-Resistance of High Side MOSFET : 82mΩ(Typ)
ON-Resistance of Low Side MOSFET : 70mΩ(Typ)
VCC=5V
Ta=25°C
10
100
1000
10000
OUTPUT CURRENT:I[mA]
Output Current :IOUT[mA]
Figure 23. Efficiency
Advantage 3：・Supplied in smaller package due to integration of small-sized power MOSFETs
・Required output capacitor ,Co, for current mode control: 22µF ceramic capacitor
・Required inductance ,L, for the operating frequency of 1 MHz: 2.2µH inductor
・Integrates FET + Boot strap diode
Reduces the required mounting area
VCC
EN
VCC
BST
20mm
CBST
VREF
Current
Comp
3.3V
Input
Cf
Rf
PVCC
SW
R2
R1
R Q
Current
Sense/
Protect
+
S
L
Output
SLOPE
OSC
CLK
Gm Amp
PVCC
CIN
+
+
15mm
VCC
RITH
Driver
Logic
PGND
GND
UVLO
Soft
Start
TSD
SCP
CITH
Co
ITH
RITH
ADJ
CITH
R2
R1
Figure 24. Example Application
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Datasheet
BD8962MUV
4. Switching Regulator Efficiency
Efficiency η may be expressed by the equation shown below:
VOUT IOUT
VIN IIN
P
P
OUT
OUT
η
100
100
100
%
P
P
Pd
IN
OUT
Efficiency may be improved by reducing the switching regulator power dissipation factors Pdα as follows:
Dissipation Factors:
(1) ON-Resistance Dissipation of Inductor and FET：Pd(I2R)
Pd
I 2R
IOUT 2
RCOIL RON
Where:
RCOIL is the DC resistance of inductor
RON is the ON-Resistance of FET
IOUT is the output current
(2) Gate Charge/Discharge Dissipation：Pd(Gate)
Pd
Gate
Cgs f V 2
Where:
Cgs is the gate capacitance of FET
f is the switching frequency
V is the gate driving voltage of FET
(3) Switching Dissipation：Pd(SW)
VIN 2 CRSS IOUT f
Pd
SW
IDRIVE
Where:
CRSS is the reverse transfer capacitance of FET
IDRIVE is the peak current of gate
(4) ESR Dissipation of Capacitor：Pd(ESR)
Pd
ESR
IRMS 2 ESR
Where:
IRMS is the ripple current of capacitor
ESR is the equivalent series resistance
(5) Operating Current Dissipation of IC：Pd(IC)
Pd
IC VIN ICC
Where:
ICC is the circuit current
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Datasheet
BD8962MUV
5. Consideration on Permissible Dissipation and Heat Generation
Since this IC functions with high efficiency without significant heat generation in most applications, no special
consideration is needed on permissible dissipation or heat generation. In case of extreme conditions, however, including
lower input voltage, higher output voltage, heavier load, and/or higher temperature, the permissible dissipation and/or
heat generation must be carefully considered.
For dissipation, only conduction losses due to the DC resistance of inductor and ON-Resistance of FET are considered
because conduction losses are more significant than other means of dissipation mentioned above including gate
charge/discharge dissipation and switching dissipation.
4.0
①3.56W
①
②
③
4 layers (Copper foil area : 5505mm2)
copper foil in each layer
θj-a=35.1°C/W
4 layers (Copper foil area : 10.29m2)
copper foil in each layer
θj-a=103.3°C/W
1 layers (Copper foil area : 10.29m2)
θj-a=178.6°C/W
P IOUT 2 RON
RON D RONH
3.0
2.0
1 D RONL
Where:
D is the ON duty (=VOUT/VCC
RONH is the ON-Resistance of High Side MOSFET
RONL is the ON-Resistance of Low Side MOSFET
IOUT is the Output Current
)
④IC only.
θj-a=367.6°C/W
②1.21W
1.0
0
③0.70W
④0.34W
0
25
50
75 100105 125
150
Ambient Temperature: Ta [°C]
Figure 25. Thermal Dissipation Curve
(VQFN020V4040)
If VCC=3.3V, VOUT=1.8V, RONH=82mΩ, RONL=70mΩ
IOUT=3A, for example,
D=VOUT/VCC=1.8/3.3=0.545
RON=0.545 x 0.082+(1-0.545) x 0.07
=0.0447+0.0319
=0.0766[Ω]
P=32 x 0.0766＝0.6894[W]
Since RONH is greater than RONL in this IC, the dissipation increases as the ON duty becomes greater. Taking into
consideration the dissipation as shown above, thermal design must be carried out with allowable sufficient margin.
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Datasheet
BD8962MUV
6. Selection of Externally Connected components
(1) Selection of Inductor (L)
The inductance significantly depends on output ripple current.
As shown in equation (1), the ripple current decreases as the
inductor and/or switching frequency increases.
IL
ΔIL
V
CCVOUT
LVCC f
VOUT
IL
A
・・・(1)
VCC
Appropriate ripple current at output should be +/-20% of the
maximum output current.
IL
VOUT
IL 0.2 IOUTMax
A
L
・・・(2)
CO
VCC VOUT
VOUT
L
H
・・・(3)
IL VCC f
Where:
Figure 26. Output Ripple Current
ΔIL is the Output ripple current, and
f is the Switching frequency
Note: Current exceeding the current rating of the inductor results in magnetic saturation of the inductor, which decreases
efficiency. The inductor must be selected to allow a sufficient margin with which the peak current may not exceed
the inductor’s current rating.
If VCC=5.0V, VOUT=2.5V, f=1MHz, ΔIL=0.2A x 3A=0.6A, for example, (BD8962MUV)
52.5 2.5
0.651M
L
2.08
2.2
H
Note: Select an inductor with low resistance component (such as DCR and ACR) to minimize dissipation in the inductor
for better efficiency.
(2) Selection of Output Capacitor (CO)
Output capacitor should be selected with consideration on the stability region
and the equivalent series resistance required in smoothing the ripple voltage.
VCC
Output ripple voltage is determined by equation (4) ：
VOUT
・・・(4)
VOUT IL ESR
V
L
ESR
CO
Where:
ΔIL is the Output ripple current, and
ESR is the Equivalent series resistance of output capacitor
Figure 27. Output Capacitor
Note: Rating of the capacitor should be determined to allow a sufficient margin
against output voltage. A 22µF to 100µF ceramic capacitor is recommended.
Less ESR allows reduction in output ripple voltage.
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Datasheet
BD8962MUV
(3) Selection of Input Capacitor (CIN)
The input capacitor must be a low ESR capacitor with a capacitance sufficient to
cope with high ripple current. This is to prevent high transient voltage. The ripple
current IRMS is given by equation (5):
VCC
CIN
VOUT
VOUT
VCC VOUT
VCC
・・・(5)
IRMS IOUT
A
L
CO
< Worst case > IRMSMax
IOUT
When VCC 2VOUT ,IRMS
2
Figure 28. Input Capacitor
If VCC=3.3V, VOUT=1.8V, and IOUTMax=3A, (BD8962MUV)
1.8
3.31.8
1.49
IRMS 3
ARMS
3.3
A low ESR 22µF/10V ceramic capacitor is recommended to reduce ESR dissipation of input capacitor for better
efficiency.
(4) Calculating RITH, CITH for Phase Compensation
Since the Current Mode Control is designed to limit the inductor current, a pole (phase lag) appears in low
frequencies due to RC filter consisting of an output capacitor and load resistance, while a zero (phase lead) appears
in high frequencies due to the output capacitor and its ESR. Therefore, phases are easily compensated by adding a
zero to the power amplifier output with C and R as described below to cancel a pole at the power amplifier.
1
fp
fp(Min)
2
ROCO
A
0
1
fp(Max)
fZ
ESR
Gain
[dB]
2 ESRCO
fZ(ESR)
IOUTMin
IOUTMax
Pole at power amplifier
0
When the output current decreases, the load resistance
Ro increases and the pole frequency decreases.
Phase
[deg]
-90
1
fp Min
[Hz] withlighterload
[Hz] withheavierload
Figure 29. Open Loop Gain Characteristics
2 ROMax CO
1
fp Max
2 ROMin CO
A
f (Amp)
z
Zero at power amplifier
Gain
[dB]
Increasing the capacitance of the output capacitor lowers the
pole frequency while the zero frequency does not change.
(This is because when the capacitance is doubled, the
capacitor ESR is reduced to half.)
0
0
Phase
[deg]
1
fZ
Amp
-90
2 RITH CITH
Figure 30. Error Amp Phase Compensation Characteristics
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Datasheet
BD8962MUV
C1
Rf
VCC
CIN
PVCC
VCC
EN
CBST
L
ADJ
VOUT
ITH
SW
GND, PGND
RITH
CITH
CO
R2
R1
Figure 31. Typical Application Circuit
Stable feedback loop may be achieved by canceling the pole fp (Min) produced by the output capacitor and the load
resistance with RC zero correction by the error amplifier.
fZ
Amp
fp
Min
1
1
2 RITH CITH
2 ROMax CO
(5) Setting the Output Voltage
L
The output voltage VOUT is determined by equation (6):
Output
・・・(6)
VOUT (R2 / R1 1)VADJ
SW
Co
R2
R1
Where:
ADJ
VADJ is the Voltage at ADJ terminal (0.8V Typ)
The required output voltage may be determined by adjusting R1 and R2.
Figure 32. Determination of Output Voltage
Output Voltage Range: 0.8V to 2.5V
Use 1 kΩ to 100 kΩ resistor for R1. When using a resistor with resistance higher than 100 kΩ, check the setup
carefully for ripple voltage etc.
3.7
3.5
The lower limit of input voltage depends on the output voltage.
Basically, it is recommended to use given condition:
VO=2.5V
3.3
3.1
2.9
2.7
VCCMin VOUT 1.2V
VO=2.0V
Figure 33. shows the necessary output current value at the
lower limit of input voltage. (DCR of inductor: 20mΩ)
These data show characteristic value of the IC. It doesn’t
guarantee the operating range.
VO=1.8V
0
1
2
3
Output Current : IOUT[A]
Figure 33. Minimum Input Voltage in each Output Voltage
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BD8962MUV
7. BD8962MUV Cautions on PC Board Layout
Figure 34. Layout Diagram
(1) Layout the input ceramic capacitor CIN closer to the pins PVCC and PGND, and the output capacitor Co closer to the
pin PGND.
(2) Layout CITH and RITH between the pins ITH and GND as near as possible with the least necessary wiring.
Note: VQFN020V4040 (BD8962MUV) has thermal PAD on the reverse of the package.
The package thermal performance may be enhanced by bonding the PAD to GND plane, which occupies a large
area of the PCB.
8. Recommended Components List for Above Application
Symbol
L
Part
Value
2.0μH
2.2μH
Manufacturer
Sumida
Series
CDR6D28MNP-2R0NC
CDR6D26NP-2R2NC
Coil
Sumida
GRM32EB11A226KE20
CIN
CO
Ceramic Capacitor
Ceramic Capacitor
22μF
22μF
Murata
Murata
GRM31CB30J226KE18
CRM18 Series
Murata
Murata
Murata
Murata
Murata
Rohm
Rohm
Rohm
Rohm
Rohm
VOUT=1.0V
1500pF
1000pF
1000pF
560pF
560pF
5.6kΩ
6.8kΩ
6.8kΩ
8.2kΩ
12kΩ
GRM18 Series
GRM18 Series
GRM18 Series
GRM18 Series
MCR03 Series
MCR03 Series
MCR03 Series
MCR03 Series
MCR03 Series
VOUT=1.2V
VOUT=1.5V
VOUT=1.8V
VOUT=2.5V
VOUT=1.0V
VOUT=1.2V
VOUT=1.5V
VOUT=1.8V
VOUT=2.5V
CITH
Ceramic Capacitor
Resistance
RITH
GRM18 Series
MCR03 Series
GRM18 Series
Cf
Rf
Ceramic Capacitor
Resistance
1000 pF
Murata
Rohm
10Ω
CBST
Ceramic Capacitor
0.1 μF
Murata
Note: The parts list presented above is an example of the recommended parts. Although the parts are standard, actual
circuit characteristics should be checked in your application carefully before use. Be sure to allow sufficient margins
to accommodate variations between external devices and this IC when employing the depicted circuit with other
circuit constants modified. Both static and transient characteristics should be considered in establishing these
margins. When switching noise is significant and may affect the system, a low pass filter should be inserted between
the VCC and PVCC pins, and a schottky barrier diode or snubber established between the SW and PGND pins.
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BD8962MUV
I/O Equivalent Circuit
PVCC
PVCC
PVCC
・EN pin
・SW pin
EN
SW
・ADJ pin
・ITH pin
VCC
ADJ
ITH
PVCC
・BST pin
PVCC
BST
SW
Figure 35. I/O Equivalent Circuit
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Datasheet
BD8962MUV
Operational Notes
1.
2.
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.
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.
4.
Ground Voltage
Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition.
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 power dissipation 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 Pd rating.
6.
7.
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.
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.
9.
Operation Under Strong Electromagnetic Field
Operating the IC in the presence of a strong electromagnetic field may cause the IC to malfunction.
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.
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BD8962MUV
Operational Notes – continued
11. 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.
12. 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
Pin B
B
E
C
Pin A
B
C
E
P
P+
P+
N
P+
P
P+
N
N
N
N
N
N
N
Parasitic
Elements
Parasitic
Elements
P Substrate
GND GND
P Substrate
GND
GND
Parasitic
Elements
Parasitic
Elements
N Region
close-by
Figure 36. Example of monolithic IC structure
13. 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 power dissipation 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.
14. Selection of Inductor
It is recommended to use an inductor with a series resistance element (DCR) 0.1Ω or less. Especially, note that use
of a high DCR inductor will cause an inductor loss, resulting in decreased output voltage. Should this condition
continue for a specified period (soft start time + timer latch time), output short circuit protection will be activated and
output will be latched OFF. When using an inductor over 0.1Ω, be careful to ensure adequate margins for variation
between external devices and this IC, including transient as well as static characteristics. Furthermore, in any case, it
is recommended to start up the output with EN after supply voltage is within.
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BD8962MUV
Ordering Information
M U V
B D 8 9 6 2
E 2
Package
MUV: VQFN020V4040
Packaging and forming specification
E2: Embossed tape and reel
Part Number
Type
Adjustable
(0.8V to 2.5V)
Marking Diagram
VQFN020V4040 (TOP VIEW)
Part Number Marking
D 8 9 6 2
LOT Number
1PIN MARK
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Datasheet
BD8962MUV
Physical Dimension Tape and Reel Information
Package Name
VQFN020V4040
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Datasheet
BD8962MUV
Revision History
Date
Revision
Changes
02.Mar.2012
02.Oct.2014
001
002
New Release
Applied the ROHM Standard Style and improved understandability.
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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
intend to use our Products in devices requiring extremely high reliability (such as medical equipment (Note 1), 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
CLASSⅣ
CLASSⅡb
CLASSⅢ
CLASSⅢ
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 (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual
ambient 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 – GE
Rev.003
© 2014 ROHM Co., Ltd. All rights reserved.
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
QR code 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 our Products might fall under controlled goods prescribed by the applicable foreign exchange and foreign trade act,
please consult with ROHM representative 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. ROHM shall not be in any way responsible or liable
for infringement of any intellectual property rights or other damages arising from use of such information or data.:
2. 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 information contained in this document.
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 – GE
Rev.003
© 2014 ROHM Co., Ltd. All rights reserved.
Daattaasshheeeett
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 not be in an y way responsible or liable for failure, malfunction or accident 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 any damages, expenses or losses incurred by you or third parties resulting from inaccuracy or errors of or
concerning such information.
Notice – WE
Rev.001
© 2014 ROHM Co., Ltd. All rights reserved.
Datasheet
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相关型号：
BD89630EFJ-E2
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