BD8964FVM-TR [ROHM]

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BD8964FVM-TR
型号: BD8964FVM-TR
厂家: ROHM    ROHM
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4.0V to 5.5V, 1.2A 1ch  
Synchronous Buck Converter Integrated FET  
BD8964FVM  
General Description  
ROHM’s high efficiency step-down switching  
Key Specifications  
Input voltage range:  
Output voltage range:  
Output current:  
4.0V to 5.5V  
1.0V to 1.8V  
1.2A (Max.)  
1.0MHz(Typ.)  
350mΩ(Typ.)  
250mΩ(Typ.)  
regulator BD8964FVM is a power supply designed  
to produce a low voltage including 1 volts from 5/3.3  
volts power supply line. Offers high efficiency with  
synchronous rectifier. Employs a current mode  
control system to provide faster transient response  
to sudden change in load.  
Switching frequency:  
Pch FET ON resistance:  
Nch FET ON resistance:  
Standby current:  
0μA (Typ..)  
Operating temperature range:  
-25to +85℃  
Features  
Offers fast transient response with current mode  
PWM control system.  
Packages  
Offers highly efficiency for all load range with  
synchronous rectifier (Nch/Pch FET)  
Incorporates soft-start function.  
Incorporates thermal protection and ULVO  
functions.  
MSOP8  
2.90mm x 4.00mm x 0.83mm  
Application  
Power supply for LSI including DSP, Micro computer  
and ASIC  
Incorporates short-current protection circuit with  
time delay function.  
Incorporates shutdown function  
Typical Application Circuit  
Cin  
L
VCC  
VCC,PVCC  
EN  
SW  
VOUT  
VOUT  
VOUT  
ITH  
ESR  
CO  
RO  
GND,PGND  
RITH  
CITH  
Fig.1 Typical application  
Product structureSilicon monolithic integrated circuit This product is not designed protection against radioactive rays.  
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Datasheet  
BD8964FVM  
Pin Configuration  
TOP VIEW)  
1
2
3
4
8
7
6
5
VCC  
ADJ  
ITH  
PVCC  
SW  
EN  
GND  
PGND  
MSOP8  
Fig.2 Pin configuration  
Pin Description  
Pin No.  
Pin name  
ADJ  
PIN function  
1
2
3
4
5
6
7
8
Output voltage detect pin  
ITH  
GmAmp output pin/Connected phase compensation capacitor  
Enable pin(Active High)  
EN  
GND  
PGND  
SW  
Ground  
Nch FET source pin  
Pch/Nch FET drain output pin  
Pch FET source pin  
PVCC  
VCC  
VCC power supply input pin  
Block Diagram  
Fig.3 Block Diagram  
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Datasheet  
BD8964FVM  
Absolute Maximum Ratings  
Parameter  
Symbol  
VCC  
Limits  
-0.3 to +7 *1  
-0.3 to +7 *1  
-0.3 to +7  
-0.3 to +7  
387.5*2  
Unit  
V
VCC Voltage  
PVCC Voltage  
PVCC  
VEN  
V
EN Voltage  
V
SW,ITH Voltage  
VSW,VITH  
Pd1  
V
Power Dissipation 1  
Power Dissipation 2  
Operating temperature range  
Storage temperature range  
mW  
mW  
Pd2  
587.4*3  
Topr  
-25 to +85  
-55 to +150  
+150  
Tstg  
Maximum junction temperature  
Tjmax  
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)  
Limits  
Unit  
Parameter  
Symbol  
Min.  
4.0  
4.0  
0
Typ.  
Max.  
5.5  
*4  
VCC Voltage  
VCC  
5.0  
V
V
V
V
A
*4  
PVCC Voltage  
PVCC  
5.0  
5.5  
EN Voltage  
VEN  
VOUT  
Isw *4  
-
-
-
VCC  
1.8  
Output voltage Setting Range  
SW average output current  
1.0  
-
1.2  
4  
Pd should not be exceeded.  
Electrical Characteristics  
(Ta=25, VCC=5V, EN=VCC, R1=20kΩ, R2=10kΩ unless otherwise specified.)  
Parameter  
Standby current  
Symbol  
ISTB  
Min.  
-
Typ.  
0
Max.  
10  
450  
0.8  
-
Unit  
μA  
μA  
V
Conditions  
EN=GND  
Bias current  
ICC  
-
250  
GND  
VCC  
1
EN Low voltage  
VENL  
VENH  
IEN  
-
Standby mode  
Active mode  
VEN=5V  
EN High voltage  
2.0  
-
V
EN input current  
Oscillation frequency  
Pch FET ON resistance  
Nch FET ON resistance  
ADJ voltage  
10  
1.2  
600  
500  
0.82  
-
μA  
MHz  
mΩ  
mΩ  
V
FOSC  
RONP  
RONN  
VADJ  
ITHSI  
0.8  
-
1
350  
250  
0.80  
20  
PVCC=5V  
PVCC=5V  
-
0.78  
10  
10  
3.6  
3.65  
0.5  
1
ITH SInk current  
μA  
μA  
V
VADJ=H  
ITH Source Current  
UVLO threshold voltage  
UVLO release voltage  
Soft start time  
ITHSO  
VUVLO1  
VUVLO2  
TSS  
20  
-
VADJ=L  
3.8  
3.90  
1
4.0  
4.2  
2
VCC=4→0V  
VCC=0→4V  
VADJ=H  
V
ms  
ms  
Timer latch time  
TLATCH  
2
3
SCP/TSD operated  
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Datasheet  
BD8964FVM  
Typical Performance Curves  
Fig.5 Ven-Vout  
Fig.4 Vcc-Vout  
0
Fig.7 Ta-VOUT  
Fig.6 Iout-Vout  
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BD8964FVM  
Fig.9 Ta-FOSC  
Fig.8 Efficiency  
Fig.10 Ta-RONN, RONP  
Fig.11 Ta-VEN  
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Datasheet  
BD8964FVM  
Fig.12 Ta-ICC  
Fig.13 Vcc-Fosc  
Fig.14 Soft start waveform  
Fig.15 SW waveform  
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Datasheet  
BD8964FVM  
Fig. 16 Transient response  
Fig.17 Transient response  
Io=100600mA(10μs)  
Io=600100mA(10μs)  
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Datasheet  
BD8964FVM  
Application Information  
Operation  
BD8964FVM is a synchronous rectifying step-down switching regulator that achieves faster transient response by  
employing current mode PWM control system.  
Synchronous rectifier  
It does not require the power to be dissipated by a rectifier externally connected to a conventional DC/DC converter IC,  
and its P.N junction shoot-through protection circuit limits the shoot-through current during operation, by which the power  
dissipation of the set is reduced.  
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 IL increases. The current comparator (Current Comp)  
receives two signals, a current feedback control signal (SENSE: Voltage converted from IL) 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  
repeat this operation.  
SENSE  
Current  
Comp  
VOUT  
RESET  
R
S
Q
IL  
Level  
Shift  
FB  
SET  
Driver  
Logic  
VOUT  
Gm Amp.  
SW  
Load  
OSC  
ITH  
Fig.18 Diagram of current mode PWM control  
PVCC  
Current  
Comp  
SENSE  
FB  
SET  
GND  
GND  
RESET  
SW  
GND  
IL(AVE)  
IL  
VOUT  
VOUT(AVE)  
Fig.19 PWM switching timing chart  
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Datasheet  
BD8964FVM  
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. And the hysteresis width  
of 300mV (Typ.) is provided to prevent output chattering.  
Hysteresis 100mV  
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  
Fig.20 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  
at least 1 ms. 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  
Operating mode  
EN  
Timer latch  
EN  
Fig.21 Short-current protection circuit with time delay timing chart  
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Datasheet  
BD8964FVM  
Information on Advantages  
Advantage 1Offers fast transient response with current mode control system.  
BD8964FVM (Load response IO=0.1A0.6A)  
Conventional product (Load response IO=0.1A0.6A)  
VOUT  
VOUT  
58mV  
110mV  
IOUT  
IOUT  
Voltage drop due to sudden change in load was reduced  
Fig.22 Comparison of transient response  
100  
Advantage 2Offers high efficiency with synchronous rectifier  
VOUT=1.5V】  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
For heavier load:  
Utilizes the synchronous rectifying mode and the low on-resistance  
MOS FETs incorporated as power transistor.  
VCC=5V  
Ta=25℃  
ON resistance of P-channel MOS FET : 350mΩ(Typ.)  
ON resistance of N-channel MOS FET : 250mΩ(Typ.)  
1
10  
100  
1000  
10000  
OUTPUT CURRENT:IOUT[mA]  
Fig.23 Efficiency  
Advantage 3:・ Supplied in smaller package due to small-sized power  
MOS FET incorporated.  
Output capacitor Co required for current mode control: 10μF ceramic capacitor  
Inductance L required for the operating frequency of 1 MHz: 4.7μH inductor  
Reduces a mounting area required.  
VCC  
15mm  
CIN  
Cin  
RITH  
CITH  
L
DC/DC  
Convertor  
Controller  
L
VOUT  
10mm  
RITH  
CITH  
Co  
CO  
Fig.24 Example application  
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Datasheet  
BD8964FVM  
Switching Regulator Efficiency  
Efficiency ŋ may be expressed by the equation shown below:  
POUT  
VOUT×IOUT  
POUT  
×100[%]=  
×100[%]  
η=  
×100[%]=  
Vin×Iin  
POUT+PDα  
Pin  
Efficiency may be improved by reducing the switching regulator power dissipation factors PDα as follows:  
Dissipation factors:  
1) ON resistance dissipation of inductor and FETPD(I2R)  
2) Gate charge/discharge dissipationPD(Gate)  
3) Switching dissipationPD(SW)  
4) ESR dissipation of capacitorPD(ESR)  
5) Operating current dissipation of ICPD(IC)  
2
1)PD(I2R)=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[Hz]Switching frequency, V[V]Gate driving voltage of FET)  
Vin2×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.  
2
P=IOUT ×(RCOIL+RON)  
RON=D×RONP+(1-D)RONN  
1000  
using an IC alone  
DON duty (=VOUT/VCC)  
RCOILDC resistance of coil  
θj-a=322.6/W  
800  
mounted on glass epoxy PCB  
RONPON resistance of P-channel MOS FET  
θj-a=212.8/W  
587.4mW  
RONNON resistance of N-channel MOS FET  
IOUTOutput current  
600  
387.5mW  
If VCC=5V, VOUT=1.5V, RCOIL=0.15Ω, RONP=0.35Ω, RONN=0.25Ω  
400  
200  
0
IOUT=0.8A, for example,  
D=VOUT/VCC=1.5/5=0.3  
RON=0.3×0.35+(1-0.3)×0.25  
=0.105+0.175  
=0.28[Ω]  
0
25  
50  
75 85 100  
125  
150  
P
=0.82×(0.15+0.28)  
275.2[mW]  
Fig. 25  
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.  
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Datasheet  
BD8964FVM  
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  
(VCC-VOUT)×VOUT  
ΔIL=  
[A]・・・(1)  
L×VCC×f  
IL  
Appropriate ripple current at output should be 30% more or less of the  
maximum output current.  
VOUT  
ΔIL=0.3×IOUTmax. [A]・・・(2)  
L
Co  
(VCC-VOUT)×VOUT  
L=  
[H]・・・(3)  
ΔIL×VCC×f  
(ΔIL: Output ripple current, and f: Switching frequency)  
Fig.26 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=5V, VOUT=1.5V, f=1MHz, ΔIL=0.3×0.8A=0.24A, for example,  
(5-1.5)×1.5  
L=  
=4.375μ → 4.7[μH]  
0.24×5×1M  
*Select the inductor of low resistance component (such as DCR andACR) 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
ΔVOUT=ΔIL×ESR [V]・・・(4)  
ESR  
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.27 Output capacitor  
As the output rise time must be designed to fall within the soft-start time, the capacitance of output capacitor should be  
determined with consideration on the requirements of equation (5):  
TSS×(Ilimit-IOUT)  
VOUT  
Tss: Soft-start time  
Ilimit: Over current detection level, 2A(Typ)  
Co≦  
・・・(5)  
In case of BD8964FVM, for instance, and if VOUT=1.5V, IOUT=0.8A, and TSS=1ms,  
1m×(2-0.8)  
Co≦  
800[μF]  
1.5  
Inappropriate capacitance may cause problem in startup. A 10 μF to 100 μF ceramic capacitor is recommended.  
3. Selection of input capacitor (Cin)  
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):  
VCC  
Cin  
VOUT(VCC-VOUT)  
IRMS=IOUT×  
[A]・・・(5)  
VOUT  
VCC  
L
Co  
< Worst case > IRMS(max.)  
IOUT  
2
When Vcc is twice the VOUT, IRMS=  
If VCC=5.0V, VOUT=1.5V, and IOUTmax.=0.8A  
Fig.28 Input capacitor  
5(5-1.5)  
IRMS=0.8×  
=0.67[ARMS]  
5
A low ESR 10μF/10V ceramic capacitor is recommended to reduce ESR dissipation of input capacitor for better efficiency.  
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Datasheet  
BD8964FVM  
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.)  
A
1
fp=  
fp(Max.)  
2π×RO×CO  
Gain  
[dB]  
0
1
fz(ESR)=  
fz(ESR)  
2π×ESR×CO  
IOUTMin.  
IOUTMax.  
Pole at power amplifier  
0
When the output current decreases, the load resistance Ro  
increases and the pole frequency lowers.  
Phase  
[deg]  
-90  
1
fp(Min.)=  
[Hz]←with lighter load  
2π×ROMax.×CO  
Fig.29 Open loop gain characteristics  
1
fp(Max.)=  
[Hz] ←with heavier load  
2π×ROMin.×CO  
A
fz(Amp.)  
Gain  
[dB]  
Zero at power amplifier  
0
0
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.)  
Phase  
[deg]  
-90  
1
fz(Amp.)=  
2π×RITH×CITH  
Fig.30 Error amp phase compensation characteristics  
Cin  
L
VCC  
VCC,PVCC  
EN  
SW  
VOUT  
VOUT  
VOUT  
ITH  
ESR  
CO  
RO  
GND,PGND  
RITH  
CITH  
Fig.31 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
1
=
2π×RITH×CITH  
2π×ROMax.×CO  
5. Determination of output voltage  
The output voltage VOUT is determined by the equation (7):  
VOUT=(R2/R1+1)×VADJ・・・(7) VADJ: Voltage at ADJ terminal (0.8V Typ.)  
With R1 and R2 adjusted, the output voltage may be determined as required.  
(Adjustable output voltage range1.0V to 1.8V)  
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.  
4.7µH  
6
1
Output  
SW  
10µF  
R2  
R1  
ADJ  
Fig.32 Determination of output voltage  
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Datasheet  
BD8964FVM  
BD8964FVM Cautions on PC Board Layout  
VCC  
EN  
1
2
8
7
EN  
ADJ  
VCC  
ITH  
PVCC  
SW  
L
3
6
5
VOUT  
RITH  
4
CIN  
Co  
GND  
PGND  
CITH  
GND  
Fig.33 Layout diagram  
For the sections drawn with heavy line, use thick conductor pattern as short as possible.  
Lay out the input ceramic capacitor CIN closer to the pins PVCC and PGND, and the output capacitor Co closer  
to the pin PGND.  
Lay out CITH and RITH between the pins ITH and GND as near as possible with least necessary wiring.  
Recommended Components Lists on Above Application  
Symbol  
Part  
Value  
Manufacturer  
Sumida  
TDK  
Kyocera  
Kyocera  
murata  
ROHM  
Series  
CMD6D11B  
VLF5014AT-4R7M1R1  
CM316X5R106K10A  
CM316X5R106K10A  
GRM18series  
L
Coil  
4.7μH  
CIN  
CO  
Ceramic capacitor  
Ceramic capacitor  
Ceramic capacitor  
10μF  
10μF  
1000pF  
CITH  
VOUT=1.0V  
4.3kΩ  
6.8kΩ  
9.1kΩ  
12kΩ  
MCR10 4301  
MCR10 6801  
MCR10 9101  
MCR10 1202  
VOUT=1.2V  
VOUT=1.5V  
VOUT=1.8V  
ROHM  
ROHM  
ROHM  
RITH  
Resistance  
* 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.  
I/O Equivalence Circuit  
PVCC  
PVCC  
PVCC  
EN pin  
SW pin  
EN  
SW  
ADJ pin  
ITH pin  
VCC  
VCC  
10kΩ  
ITH  
ADJ  
Fig.34 I/O equivalence circuit  
www.rohm.com  
TSZ02201-0J3J0AJ00050-1-2  
02.MAR.2012 Rev.001  
©
ROHM Co., Ltd. All rights reserved.  
14/16  
TSZ2211115001  
Datasheet  
BD8964FVM  
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 35.  
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.35 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.  
9. Selection of inductor  
It is recommended to use an inductor with a series resistance element (DCR) 0.1Ω or less. 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 operation range.  
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  
TSZ02201-0J3J0AJ00050-1-2  
©
ROHM Co., Ltd. All rights reserved.  
15/16  
TSZ2211115001  
02.MAR.2012 Rev.001  
Datasheet  
BD8964FVM  
Ordering Information  
B D 8  
9
6 4  
F
V
M -  
T R  
Package  
Packaging and forming specification  
TR: Embossed tape and reel  
FVM:MSOP8  
Physical Dimension Tape and Reel information  
Marking Diagram  
MSOP8(TOP VIEW)  
Part Number Marking  
D
8
9
LOT Number  
6
4
1PIN MARK  
www.rohm.com  
ROHM Co., Ltd. All rights reserved.  
TSZ2211115001  
TSZ02201-0J3J0AJ00050-1-2  
02.MAR.2012 Rev.001  
©
16/16  
Daattaasshheeeett  
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  
Daattaasshheeeett  
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  

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