Rohm BD9161FVM 2.5v to 4.5v, 0.6a 1ch synchronous buck converter integrated fet Datasheet

Datasheet
2.5V to 4.5V, 0.6A 1ch
Synchronous Buck Converter Integrated FET
BD9161FVM
●General Description
ROHM’s high efficiency step-down switching regulator
BD9161FVM is a power supply designed to produce
1.2volts (low voltage) from 3.3volts power supply line.
Offers high efficiency with our original pulse skip
control technology and synchronous rectifier.
Employs a current mode control system to provide
faster transient response to sudden change
in load.
●Key Specifications
 Input voltage range:
 Output voltage range:
 Output current:
 Switching frequency:
 Pch FET ON resistance:
 Nch FET ON resistance:
 Standby current:
 Operating temperature range:
●Features
 Offers fast transient response with current mode
PWM control system.
 Offers highly efficiency for all load range with
synchronous rectifier (Nch/Pch FET)
 Incorporates 100% Duty function.
 Incorporates soft-start function.
 Incorporates thermal protection and ULVO
functions.
 Incorporates short-current protection circuit with
time delay function.
 Incorporates shutdown function Icc=0μA (Typ.)
●Package
MSOP8:
2.5V to 4.5V
1.0V to 3.3V
0.6A(Max.)
1MHz(Typ.)
0.35Ω(Typ.)
0.37Ω(Typ.)
0μA (Typ.)
-25℃ to +85℃
2.90 mm x 4.00 mm x 0.83 mm
●Applications
Power supply for HDD, DVD and for LSI of CPU, ASIC
●Typical Application Circuit
VCC
Cin
L
VCC,PVCC
EN
VOUT
SW
VOUT
VOUT
ESR
ITH
RO
CO
GND,PGND
RITH
CITH
Fig.1 Typical application circuit
○Product structure:Silicon monolithic integrated circuit
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・14・001
○This product is not designed protection against radioactive rays.
1/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
●Pin Configuration
(TOP
VIEW)
Fig.2 Pin Configuration
●Pin Description
Pin No.
1
Pin name
ADJ
PIN function
Output voltage Feedback pin (Adjustable)
2
ITH
GmAmp output pin/Connected phase compensation capacitor
3
EN
Enable pin (Active High)
4
GND
5
PGND
6
SW
7
PVCC
8
VCC
Ground
Nch FET source pin
Pch/Nch FET drain output pin
Pch FET source pin
VCC power supply input pin
●Block Diagram
VCC
EN
3
VCC
8
VREF
3.3V
Input
7
PVCC
Current
Comp.
R
Gm Amp.
Q
Current
Sense/
Protect
S
SLOPE
VCC
Output
CLK
+
OSC
SW
Driver
Logic
UVLO
Soft
Start
PGND
5
TSD
4
SCP
1
6
GND
2
ADJ
ITH
Fig.3 Block Diagram
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
2/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
●Absolute Maximum Ratings(Ta=25℃)
Parameter
VCC voltage
PVCC voltage
EN Voltage
SW, ITH Voltage
Symbol
Rating
Unit
VCC
-0.3 to +7 *1
V
PVCC
-0.3 to +7 *1
V
EN
-0.3 to +7
V
SW,ITH
-0.3 to +7
V
Power Dissipation 1
Pd1
387.5*2
mW
Power Dissipation 2
Pd2
587.4*3
mW
Operating temperature range
Topr
-25 to +85
℃
Storage temperature range
Tstg
-55 to +150
℃
Tjmax
+150
℃
EN voltage
*1 Pd should not be exceeded.
*2 Derating in done 3.1mW/℃ for temperatures above Ta=25℃.
*3 Derating in done 4.7mW/℃ for temperatures above Ta=25℃,Mounted on 70mm×70mm×1.6mm Glass Epoxy PCB.
●Operating Ratings(Ta=25℃)
Parameter
VCC voltage
PVCC voltage
EN voltage
Output Voltage Setting Range
SW, ITH average output current
Symbol
*4
VCC
*4
PVCC
Min.
Limits
Typ.
Max.
2.5
3.3
4.5
V
Unit
2.5
3.3
4.5
V
EN
0
-
VCC
V
SW,ITH
1.0
-
3.3
V
-
-
0.6
A
*4
Isw
*4 Pd should not be exceeded.
●Electrical Characteristics
◎(Ta=25℃, VCC=PVCC=3.3V, EN=VCC, unless otherwise specified.)
Limits
Parameter
Symbol
Min.
Typ.
Standby current
ISTB
-
Max.
Unit
0
10
μA
Conditions
EN=GND
ICC
-
200
400
μA
EN Low voltage
VENL
-
GND
0.8
V
Standby mode
EN High voltage
VENH
2.0
VCC
-
V
Active mode
EN input current
IEN
-
1
10
μA
VEN=3.3V
FOSC
0.8
1
1.2
MHz
Pch FET ON resistance
RONP
-
0.35
0.6
Ω
PVCC=3.3V
Nch FET ON resistance
RONN
-
0.37
0.68
Ω
PVCC=3.3V
Output voltage
VOUT
0.784
0.8
0.816
V
ITH SInk current
ITHSI
10
20
-
μA
VOUT =H
ITH Source Current
ITHSO
10
20
-
μA
VOUT =L
Bias current
Oscillation frequency
UVLO threshold voltage
VUVLO1
2.2
2.3
2.4
V
VCC=H→L
UVLO hysteresis voltage
VUVLO2
2.22
2.35
2.5
V
VCC=L→H
Soft start time
Timer latch time
Output Short circuit
Threshold Voltage
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
TSS
0.5
1
2
ms
TLATCH
1
2
3
ms
VSCP
-
0.4
0.56
V
3/17
SCP/TSD operated
VOUT =H→L
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
●Typical Performance Curves
Fig.5 Ven-Vout
Fig.4 Vcc-Vout
Fig.7 Ta-VOUT
Fig.6 Iout-Vout
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
4/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
Fig.8 Efficiency
Fig.9 Ta - Fosc
Fig.11 Ta-ICC
Fig.10 Ta-VEN
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
5/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
Fig.13 Soft start waveform
Fig.12 Vcc-Fosc
Fig.14 SW waveform Io=10mA
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
Fig.15 SW waveform Io=500mA
6/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
Fig. 16 SW waveform Io=600mA
Fig. 17 Transient response
Io=250→500mA(10μs)
Fig.18 Transient response
Io=500→250mA(10μs)
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
7/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
●Application Information
Operation
BD9161FVM is a synchronous rectifying step-down switching regulator that achieves faster transient response by
employing current mode PWM control system. It utilizes switching operation in PWM (Pulse Width Modulation) mode for
TM
heavier load, while it utilizes SLLM (Simple Light Load Mode) operation for lighter load to improve efficiency.
○Current mode PWM control
Synthesizes a PWM control signal with a inductor current feedback loop added to the voltage feedback.
・PWM (Pulse Width Modulation) control
The oscillation frequency for PWM is 1 MHz. SET signal form OSC turns ON a P-channel MOS FET (while a
N-channel MOS FET is turned OFF), and an inductor current I L increases. The current comparator (Current Comp)
receives two signals, a current feedback control signal (SENSE: Voltage converted from I L) and a voltage feedback
control signal (FB), and issues a RESET signal if both input signals are identical to each other, and turns OFF the
P-channel MOS FET (while a N-channel MOS FET is turned ON) for the rest of the fixed period. The PWM control
repeats this operation.
TM
・SLLM (Simple Light Load Mode) control
When the control mode is shifted from PWM for heavier load to the one for lighter load or vise versa, the switching
pulse is designed to turn OFF with the device held operated in normal PWM control loop, which allows linear operation
without voltage drop or deterioration in transient response during the mode switching from light load to heavy load or
vise versa.
Although the PWM control loop continues to operate with a SET signal from OSC and a RESET signal from Current
Comp, it is so designed that the RESET signal is held issued if shifted to the light load mode, with which the switching
is tuned OFF and the switching pulses are thinned out under control. Activating the switching intermittently reduces
the switching dissipation and improves the efficiency.
・100% Duty control
Max duty is 100%. (@ Pch MOS FET always ON) In usual PWM control, in case output voltage cannot keep (ex, drop
of input voltage), oscillation frequency becomes lower and finally it becomes 100% duty. The output voltage is a value
that depends only by on a voltage hang from the input voltage to Pch MOS FET, and can keep the output voltage even
with the low input voltage.
SENSE
Current
Comp
VOUT
Level
Shift
FB
RESET
SET
Gm Amp.
ITH
R Q
S
IL
Driver
Logic
VOUT
SW
Load
OSC
Fig.19 Diagram of current mode PWM control
PVCC
Current
Comp
SENSE
PVCC
SENSE
Current
Comp
FB
FB
SET
GND
SET
GND
RESET
GND
RESET
GND
SW
GND
SW
IL
GND
IL(AVE)
IL
0A
VOUT
VOUT
VOUT(AVE)
VOUT(AVE)
Not switching
TM
Fig.21 SLLM
Fig.20 PWM switching timing chart
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
8/17
switching timing chart
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
Description of Operations
・Soft-start function
EN terminal shifted to “High” activates a soft-starter to gradually establish the output voltage with the current limited
during startup, by which it is possible to prevent an overshoot of output voltage and an inrush current.
・Shutdown function
With EN terminal shifted to “Low”, the device turns to Standby Mode, and all the function blocks including reference
voltage circuit, internal oscillator and drivers are turned to OFF. Circuit current during standby is 0μF (Typ.).
・UVLO function
Detects whether the input voltage sufficient to secure the output voltage of this IC is supplied.
of 50 mV (Typ.) is provided to prevent output chattering.
And the hysteresis width
Hysteresis 50mV
VCC
EN
VOUT
Tss
Tss
Tss
Soft start
Standby mode
Operating mode
Standby
mode
Standby
mode
Operating mode
UVLO
UVLO
Operating mode
EN
Standby mode
UVLO
Fig.22 Soft start, Shutdown, UVLO timing chart
・Short-current protection circuit with time delay function
Turns OFF the output to protect the IC from breakdown when the incorporated current limiter is activated continuously for
the fixed time (TLATCH) or more. The output thus held tuned OFF may be recovered by restarting EN or by re-unlocking
UVLO.
EN
Output OFF
latch
VOUT
Limit
IL
1msec
Standby
mode
Standby
mode
Operating mode
Timer latch
EN
Operating mode
EN
Fig.23 Short-current protection circuit with time delay timing chart
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
9/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
Information on Advantages
Advantage 1:Offers fast transient response with current mode control system.
Conventional product (VOUT of which is 2.5 volts)
BD9161FVM (Load response IO=250mA→500mA)
VOUT
VOUT
40mV
98mV
IOUT
IOUT
Voltage drop due to sudden change in load was reduced by about 50%.
Fig.24 Comparison of transient response
Advantage 2: Offers high efficiency for all load range.
・For lighter load:
TM
Utilizes the current mode control mode called SLLM
for lighter load, which reduces various dissipation such as
switching dissipation (PSW), gate charge/discharge dissipation, ESR dissipation of output capacitor (P ESR) and
on-resistance dissipation (PRON) that may otherwise cause degradation in efficiency for lighter load.
Achieves efficiency improvement for lighter load.
100
SLLMTM
Efficiency η[%]
・For heavier load:
Utilizes the synchronous rectifying mode and the low on-resistance
MOS FETs incorporated as power transistor.
ON resistance of P-channel MOS FET: 0.35 Ω (Typ.)
ON resistance of N-channel MOS FET: 0.37 Ω (Typ.)
②
50
①
PWM
①inprovement by SLLMTM system
②improvement by synchronous rectifier
0
0.001
0.01
0.1
Output current Io[A]
1
Fig.25 Efficiency
Achieves efficiency improvement for heavier load.
Offers high efficiency for all load range with the improvements mentioned above.
Advantage 3: ・Supplied in smaller package due to small-sized power MOS FET incorporated.
・Allows reduction in size of application products
・Output capacitor Co required for current mode control: 10 μF ceramic capacitor
・Inductance L required for the operating frequency of 1 MHz: 4.7 μH inductor
Reduces a mounting area required.
VCC
15mm
Cin
CIN
DC/DC
Convertor
Controller
RITH
RITH
L
VOUT
L
10mm
CITH
Co
CO
CITH
Fig.26 Example application
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
10/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
Switching Regulator Efficiency
Efficiency ŋ may be expressed by the equation shown below:
POUT ×100[%]=
POUT
η= VOUT×IOUT ×100[%]=
×100[%]
Vin×Iin
Pin
POUT+PDα
Efficiency may be improved by reducing the switching regulator power dissipation factors PDα as follows:
Dissipation factors:
2
1) ON resistance dissipation of inductor and FET:PD(I R)
2) Gate charge/discharge dissipation:PD(Gate)
3) Switching dissipation:PD(SW)
4) ESR dissipation of capacitor:PD(ESR)
5) Operating current dissipation of IC:PD(IC)
2
2
1)PD(I R)=IOUT ×(RCOIL+RON) (RCOIL[Ω]:DC resistance of inductor, RON[Ω]:ON resistance of FET
IOUT[A]:Output current.)
2)PD(Gate)=Cgs×f×V (Cgs[F]:Gate capacitance of FET, f[H]:Switching frequency, V[V]:Gate driving voltage of FET)
2
Vin ×CRSS×IOUT×f
3)PD(SW)=
(CRSS[F]:Reverse transfer capacitance of FET, IDRIVE[A]:Peak current of gate.)
IDRIVE
2
4)PD(ESR)=IRMS ×ESR (IRMS[A]:Ripple current of capacitor, ESR[Ω]:Equivalent series resistance.)
5)PD(IC)=Vin×ICC (ICC[A]:Circuit current.)
Consideration on Permissible Dissipation and Heat Generation
As 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 DC resistance of inductor and ON resistance of FET are considered.
Because the conduction losses are considered to play the leading role among other dissipation mentioned above including
gate charge/discharge dissipation and switching dissipation.
Power dissipation:Pd [mW]
1000
800
600
400
2
P=IOUT ×(RON)
RON=D×RONP+(1-D)×RONN
①Using an IC alone
θj-a=322.6℃/W
②mounted on glass epoxy PCB
θj-a=212.8℃/W
D:ON duty (=VOUT/VCC)
RONP:ON resistance of P-channel MOS FET
RONN:ON resistance of N-channel MOS FET
IOUT:Output current
②587.4mW
①387.5mW
200
0
0
25
50
75 85 100
125
150
Ambient temperature:Ta [℃]
Fig.27 Thermal derating curve
(MSOP8)
If VCC=3.3V, VOUT=2.5V RONP=0.35Ω, RONN=0.37Ω
IOUT=0.6A, for example,
D=VOUT/VCC=2.5/3.3=0.758
RON=0.758×0.35+(1-0.758)×0.37
=0.2653+0.08954
=0.35484[Ω]
2
P=0.6 ×0.35484
≒127.7[mV]
As RONP is greater than RONN in this IC, the dissipation increases as the ON duty becomes greater. With the consideration
on the dissipation as above, thermal design must be carried out with sufficient margin allowed.
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
11/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
Selection of Components Externally Connected
1. Selection of inductor (L)
IL
The inductance significantly depends on output ripple current.
As seen in the equation (1), the ripple current decreases as the
inductor and/or switching frequency increases.
ΔIL
VCC
ΔIL=
(VCC-VOUT)×VOUT
[A]・・・(1)
L×VCC×f
Appropriate ripple current at output should be 20 to 30% more or less
of the maximum output current.
ΔIL=0.25×IOUTmax. [A]・・・(2)
IL
VOUT
L
Co
(VCC-VOUT)×VOUT
L=
[H]・・・(3)
ΔIL×VCC×f
(ΔIL: Output ripple current, and f: Switching frequency)
Fig.28 Output ripple current
* Current exceeding the current rating of the inductor results in magnetic saturation of the inductor, which decreases
efficiency. The inductor must be selected allowing sufficient margin with which the peak current may not exceed its
current rating.
If VCC=3.3V, VOUT=2.5V, f=1MHz, ΔIL=0.25×0.6A=0.15A
(3.3-2.5)×2.5
L≧ 0.15×3.3×1M
≧4.04μ
* Select the inductor of low resistance component (such as DCR and ACR) to minimize dissipation in the inductor for
better efficiency.
2. Selection of output capacitor (CO)
VCC
Output capacitor should be selected with the consideration on the stability
region and the equivalent series resistance required to smooth ripple voltage.
Output ripple voltage is determined by the equation (4):
VOUT
L
ESR
ΔVOUT=ΔIL×ESR [V]・・・(4)
Co
(ΔIL: Output ripple current, ESR: Equivalent series resistance of output capacitor)
*Rating of the capacitor should be determined allowing sufficient margin against
output voltage. Less ESR allows reduction in output ripple voltage.
Fig.29 Output capacitor
Inappropriate capacitance may cause problem in startup.
A 10μF to 100μF ceramic capacitor is recommended.
3. Selection of input capacitor (Cin)
VCC
Input capacitor to select must be a low ESR capacitor of the capacitance
sufficient to cope with high ripple current to prevent high transient voltage. The
ripple current IRMS is given by the equation (5):
Cin
√VOUT(VCC-VOUT)
VOUT
L
IRMS=IOUT×
VCC
Co
[A]・・・(5)
< Worst case > IRMS(max.)
IOUT
When VCC is twice the Vout,
2
IRMS=
Fig.30 Input capacitor
If VCC=3.3V, VOUT=2.5V, and IOUTmax.=0.6A
√2.5(3.3-2.5)
IRMS=0.6×
=0.284[ARMS]
5
A low ESR 10μF/10V ceramic capacitor is recommended to reduce ESR dissipation of input capacitor for better efficiency.
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
12/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
4. Determination of RITH, CITH that works as a phase compensator
As the Current Mode Control is designed to limit a inductor current, a pole (phase lag) appears in the low frequency area
due to a CR filter consisting of a output capacitor and a load resistance, while a zero (phase lead) appears in the high
frequency area due to the output capacitor and its ESR. So, the 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.
fp(Min.)
1
2π×RO×CO
1
fz(ESR)=
2π×ESR×CO
A
Gain
[dB]
fp=
fp(Max.)
0
fz(ESR)
IOUTMin.
IOUTMax.
Pole at power amplifier
When the output current decreases, the load resistance Ro
increases and the pole frequency lowers.
0
Phase
[deg]
-90
fp(Min.)=
1
2π×ROMax.×CO
[Hz]←with lighter load
fp(Max.)=
1
2π×ROMin.×CO
[Hz]←with heavier load
Fig.31 Open loop gain characteristics
A
fz(Amp.)
Zero at power amplifier
Increasing 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 reduces to half.)
Gain
[dB]
0
0
Phase
[deg]
fz(Amp.)=
-90
1
2π×RITH.×CITH
Fig.32 Error amp phase compensation characteristics
VCC
Cin
EN
VOUT
L
VCC,PVCC
SW
VOUT
ITH
VOUT
ESR
GND,PGND
RO
CO
RITH
CITH
Fig.33 Typical application
Stable feedback loop may be achieved by canceling the pole fp (Min.) produced by the output capacitor and the load
resistance with CR zero correction by the error amplifier.
fz(Amp.)= fp(Min.)
1
2π×RITH×CITH
=
1
2π×ROMax.×CO
5. Determination of output voltage
The output voltage VOUT is determined by the equation (6):
VOUT=(R2/R1+1)×VADJ・・・(6) VADJ: Voltage at ADJ terminal (0.8V Typ.)
With R1 and R2 adjusted, the output voltage may be determined as required.
(Adjustable output voltage range: 1.0V to 3.3V )
L
6
Output
SW
R2
1
ADJ
Use 1 kΩ to 100 kΩ resistor for R1. If a resistor of the resistance higher than
100 kΩ is used, check the assembled set carefully for ripple voltage etc.
Co
R1
Fig.34 Determination of output voltage
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
13/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
BD9161FVM Cautions on PC Board Layout
Fig.35 Board layout
① For the sections drawn with heavy line, use thick conductor pattern as short as possible.
② Lay out the input ceramic capacitor CIN closer to the pins PVCC and PGND, and the output capacitor Co closer to the
pin PGND.
③ Lay out CITH and RITH between the pins ITH and GND as neat as possible with least necessary wiring.
Recommended Component Lists With Above Applications
Symbol Part
Value
L
RIN
CIN
CO
Coil
Resistance
Ceramic capacitor
Ceramic capacitor
Ceramic capacitor
CITH
RITH
Resistance
4.7μH
10Ω
10μF
10μF
VOUT=1.0V
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
820pF
560pF
470pF
470pF
330pF
6.8kΩ
8.2Ω
12kΩ
12kΩ
15kΩ
Manufacturer
TDK
Sumida
ROHM
Kyocera
Kyocera
murata
murata
murata
murata
murata
ROHM
ROHM
ROHM
ROHM
ROHM
Series
VLF5014AT-4R7M1R1
CMD6D11B
MCR03 Series
CM316X5R106K10A
CM316X5R106K10A
GRM18 Series
GRM18 Series
GRM18 Series
GRM18 Series
GRM18 Series
MCR03 Series
MCR03 Series
MCR03 Series
MCR03 Series
MCR03 Series
* The parts list presented above is an example of recommended parts. Although the parts are sound, actual circuit characteristics should be checked on 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 substantial and may impact the system, a low pass filter should be inserted between the VCC and PVCC pins, and a schottky barrier
diode established between the SW and PGND pins.
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
14/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
●I/O Equivalence Circuit
PVCC
・SW pin
・EN pin
PVCC
PVCC
10kΩ
EN
SW
・ITH pin
・ADJ pin
VCC
10kΩ
ADJ
ITH
Fig.36 I/O equivalence circuit
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
15/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
●Operational Notes
1. Absolute Maximum Ratings
While utmost care is taken to quality control of this product, any application that may exceed some of the absolute maximum
ratings including the voltage applied and the operating temperature range may result in breakage. If broken, short-mode or
open-mode may not be identified. So if it is expected to encounter with special mode that may exceed the absolute
maximum ratings, it is requested to take necessary safety measures physically including insertion of fuses.
2. Electrical potential at GND
GND must be designed to have the lowest electrical potential In any operating conditions.
3. Short-circuiting between terminals, and mismounting
When mounting to pc board, care must be taken to avoid mistake in its orientation and alignment. Failure to do so may
result in IC breakdown. Short-circuiting due to foreign matters entered between output terminals, or between output and
power supply or GND may also cause breakdown.
4.Operation in Strong electromagnetic field
Be noted that using the IC in the strong electromagnetic radiation can cause operation failures.
5. Thermal shutdown protection circuit
Thermal shutdown protection circuit is the circuit designed to isolate the IC from thermal runaway, and not intended to
protect and guarantee the IC. So, the IC the thermal shutdown protection circuit of which is once activated should not
be used thereafter for any operation originally intended.
6. Inspection with the IC set to a pc board
If a capacitor must be connected to the pin of lower impedance during inspection with the IC set to a pc board, the
capacitor must be discharged after each process to avoid stress to the IC. For electrostatic protection, provide proper
grounding to assembling processes with special care taken in handling and storage. When connecting to jigs in the
inspection process, be sure to turn OFF the power supply before it is connected and removed.
7. Input to IC terminals
+
This is a monolithic IC with P isolation between P-substrate and each element as illustrated below. This P-layer and
the N-layer of each element form a P-N junction, and various parasitic element are formed.
If a resistor is joined to a transistor terminal as shown in Fig 37:
○P-N junction works as a parasitic diode if the following relationship is satisfied; GND>Terminal A (at resistor side), or
GND>Terminal B (at transistor side); and
○if GND>Terminal B (at NPN transistor side),
a parasitic NPN transistor is activated by N-layer of other element adjacent to the above-mentioned parasitic diode.
The structure of the IC inevitably forms parasitic elements, the activation of which may cause interference among circuits,
and/or malfunctions contributing to breakdown. It is therefore requested to take care not to use the device in such
manner that the voltage lower than GND (at P-substrate) may be applied to the input terminal, which may result in
activation of parasitic elements.
Fig.37 Simplified structure of monorisic IC
8. Ground wiring pattern
If small-signal GND and large-current GND are provided, It will be recommended to separate the large-current GND
pattern from the small-signal GND pattern and establish a single ground at the reference point of the set PCB so that
resistance to the wiring pattern and voltage fluctuations due to a large current will cause no fluctuations in voltages of the
small-signal GND. Pay attention not to cause fluctuations in the GND wiring pattern of external parts as well.
Status of this document
The Japanese version of this document is formal specification. A customer may use this translation version only for a reference
to help reading the formal version.
If there are any differences in translation version of this document formal version takes priority
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
16/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
BD9161FVM
●Ordering Information
B
D
9
1
6
1
F
V
M
Package
FVM: MSOP8
-
TR
Packaging and forming specification
TR: Embossed tape and reel
●Physical Dimension, Tape and Reel information
●Marking Diagram
MSOP8(TOP VIEW)
Part Number Marking
D
6
9
1
1
LOT Number
1PIN MARK
www.rohm.com
© 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
17/17
TSZ02201-0J3J0AJ00190-1-2
02.MAR.2012 Rev.001
Datasheet
Notice
●Precaution for circuit design
1) The products are designed and produced for application in ordinary electronic equipment (AV equipment, OA
equipment, telecommunication equipment, home appliances, amusement equipment, etc.). If the products are to be
used in devices requiring extremely high reliability (medical equipment, transport equipment, aircraft/spacecraft,
nuclear power controllers, fuel controllers, car equipment including car accessories, safety devices, etc.) and whose
malfunction or operational error may endanger human life and sufficient fail-safe measures, please consult with the
ROHM sales staff in advance. If product malfunctions may result in serious damage, including that to human life,
sufficient fail-safe measures must be taken, including the following:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits in the case of single-circuit failure
2)
The products are designed for use in a standard environment and not in any special environments. Application of the
products in a special environment can deteriorate product performance. Accordingly, verification and confirmation of
product performance, prior to use, is recommended if used under the following conditions:
[a] Use in various types of liquid, including water, oils, chemicals, and organic solvents
[b] Use outdoors where the products are exposed to direct sunlight, or in dusty places
[c] Use in places where the products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2,
and NO2
[d] Use in places where the products are exposed to static electricity or electromagnetic waves
[e] Use in proximity to heat-producing components, plastic cords, or other flammable items
[f] Use involving sealing or coating the products with resin or other coating materials
[g] Use involving unclean solder or use of water or water-soluble cleaning agents for cleaning after soldering
[h] Use of the products in places subject to dew condensation
3)
The products are not radiation resistant.
4)
Verification and confirmation of performance characteristics of products, after on-board mounting, is advised.
5)
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.
6)
De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta).
When used in sealed area, confirm the actual ambient temperature.
7)
Confirm that operation temperature is within the specified range described in product specification.
8)
Failure induced under deviant condition from what defined in the product specification cannot be guaranteed.
●Precaution for Mounting / Circuit board design
1) When a highly active halogenous (chlorine, bromine, etc.) flux is used, the remainder of flux may negatively affect
product performance and reliability.
2)
In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the
Company in advance.
Regarding Precaution for Mounting / Circuit board design, please specially refer to ROHM Mounting specification
●Precautions Regarding Application Examples and External Circuits
1) If change is made to the constant of an external circuit, allow a sufficient margin due to variations of the characteristics
of the products and external components, including transient characteristics, as well as static characteristics.
2)
The application examples, their constants, and other types of information contained herein are applicable only when
the products are used in accordance with standard methods. Therefore, if mass production is intended, sufficient
consideration to external conditions must be made.
Notice - Rev.001
Datasheet
●Precaution for Electrostatic
This product is Electrostatic sensitive product, which may be damaged due to Electrostatic discharge. Please take proper
caution during manufacturing and storing so that voltage exceeding Product maximum rating won't 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 following places:
[a] Where the products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2
[b] Where the temperature or humidity exceeds those recommended by the Company
[c] Storage in direct sunshine or condensation
[d] Storage in 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 recommended storage time period .
3)
Store / transport cartons in the correct direction, which is indicated on a carton as 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 dry bag.
●Precaution for product label
QR code printed on ROHM product label is only for internal use, and please do not use at customer site. It might contain a
internal part number that is inconsistent with an product part number.
●Precaution for disposition
When disposing products please dispose them properly with a industry waste company.
●Precaution for Foreign exchange and Foreign trade act
Since concerned goods might be fallen under controlled goods prescribed by Foreign exchange and Foreign trade act,
please consult with ROHM in case of export.
●Prohibitions Regarding Industrial Property
1) Information and data on products, including application examples, contained in these specifications are simply for
reference; the Company does not guarantee any industrial property rights, intellectual property rights, or any other
rights of a third party regarding this information or data. Accordingly, the Company does not bear any responsibility for:
[a] infringement of the intellectual property rights of a third party
[b] any problems incurred by the use of the products listed herein.
2)
The Company prohibits the purchaser of its products to exercise or use the intellectual property rights, industrial
property rights, or any other rights that either belong to or are controlled by the Company, other than the right to use,
sell, or dispose of the products.
Notice - Rev.001
Similar pages