BD9109FVM-LB [ROHM]

本产品是面向工业设备市场的产品，保证可长期稳定供货。是适合这些用途的产品。罗姆的高效率降压开关稳压器(BD9109FVM-LB)是通过5V以下的电源线生成3.3V等低电压的电源。采用独创的脉冲跳跃控制方式和同步整流电路，实现高效化。采用电流模式控制方式，实现了负载突变时的高速瞬态响应。;


型号：	BD9109FVM-LB
厂家：	ROHM
描述：	本产品是面向工业设备市场的产品，保证可长期稳定供货。是适合这些用途的产品。罗姆的高效率降压开关稳压器(BD9109FVM-LB)是通过5V以下的电源线生成3.3V等低电压的电源。采用独创的脉冲跳跃控制方式和同步整流电路，实现高效化。采用电流模式控制方式，实现了负载突变时的高速瞬态响应。开关脉冲稳压器
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Datasheet

Synchronous Buck Converter

Integrated FET

BD9109FVM-LB

General Description

Key Specifications

This is the product guarantees long time support in

Industrial market.

Input Voltage Range:

4.5V to 5.5V

3.30V ± 2%

0.8A(Max)

1MHz(Typ)

350m(Typ)

250m(Typ)

0μA (Typ)

Output Voltage Range:

Output Current:

Switching Frequency:

Pch FET On Resistance:

Nch FET On Resistance:

Standby Current:

ROHM’s high efficiency step-down switching regulators

(BD9109FVM-LB) is a power supply designed to

produce a low voltage including 3.3 volts from 5 volts

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.

Operating Temperature Range:

-25°C to +85°C

Package

W(Typ) x D(Typ) x H(Max)

2.90mm x4.00mm x 0.90mm

MSOP8

Features

Long Time Support Product for Industrial

Applications.

Fast Transient Response with Current Mode PWM

Control System.

Highly Efficiency with Synchronous Rectifier

(Nch/Pch FET) and SLLM^TM(Simple Light Load

Mode)

Soft-Start Function.

Thermal Protection and ULVO Functions.

Short-Current Protection Circuit with Time Delay

Function.

Shutdown Function

Applications

Industrial Equipment

Power supply for LSI including DSP, Micro computer

and ASIC

MSOP8

Secondary Power Supply

Typical Application Circuit

VCC

Cin

VCC,PVCC

VOUT

ITH

GND,PGND

RITH

CITH

Figure 1. Typical Application Circuit

〇Product structure : Silicon monolithic integrated circuit 〇This product has no designed protection against radioactive rays

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Pin Configuration

(Top View)

VOUT

ITH

VCC

PVCC

GND

PGND

Figure 2. Pin Configuration

Function

Pin Description

Pin No.

Pin Name

V_OUT

ITH

Output voltage detect pin

GmAmp output pin/Connected phase compensation capacitor

Enable pin(Active High)

GND

PGND

Ground

Nch FET source pin

Pch/Nch FET drain output pin

Pch FET source pin

PV_CC

V_CC

V_CCpower supply input pin

Block Diagram

VCC

VREF

PVCC

Current

Comp.

Current

Sense/

Protect

Gm Amp.

SLOPE

CLK

OSC

VCC

Driver

Logic

UVLO

PGND

Soft

Start

TSD

SCP

GND

V_OUT

ITH

Figure 3. Block Diagram

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Description of Block

BD9109FVM-LB 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

heavier load, while it utilizes SLLM^TM(Simple Light Load Mode) operation for lighter load to improve efficiency.

○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 I_Lincreases. 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

repeat this operation.

Conventional product (VOUT of which is 3.3 volts)

BD9109FVM-LB (Load response IO=100mA→600mA)

VOUT

228mV

110mV

IOUT

Voltage drop due to sudden change in load was reduced by about 50%.

Figure 4. Comparison of transient response

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Description of Block – continued

・SLLM^TM(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

SLLM^TM

②

①

①improvement by SLLM^TMsystem

PWM

②improvement by synchronous rectifier

0.001

0.01

0.1

Output current Io[A]

Figure 5. Efficiency

SENSE

Current

Comp

VOUT

RESET

Level

Shift

SET

Driver

Logic

VOUT

Gm Amp.

Load

OSC

ITH

Figure 6. Diagram of current mode PWM control

PVCC

SENSE

PVCC

Current

Comp

Current

SENSE

Comp

SET

GND

RESET

GND

IL(AVE)

VOUT

VOUT(AVE)

Not switching

Figure 8. SLLM^TMswitching timing chart

Figure 7 . PWM switching timing chart

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Description of Block – continued

・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 0 μA (Typ).

・UVLO function

Detects whether the input voltage sufficient to secure the output voltage of this IC is supplied. And the hysteresis width of

50 to 300 mV (Typ) is provided to prevent output chattering.

Hysteresis 50 to 300mV

VCC

VOUT

Tss

Soft start

Standby

mode

Standby

mode

Standby mode

Operating mode

Standby mode

UVLO

*Soft Start time(typ)

Figure 9 . Soft start, Shutdown, UVLO timing chart

BD9109FVM-LB

Unit

msec

Tss

・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.

Output OFF

latch

VOUT

Limit

T_LATCH

Standby

mode

Standby

mode

Operating mode

Timer latch

*Timer Latch time (typ)

Figure 10 . Short-current protection circuit with time delay timing char

BD9109FVM-LB

Unit

msec

TLATCH

In addition to current limit circuit, output short detect circuit is built in on BD9109FVM-LB. If output voltage fall below

2V(typ, BD9109FVM-LB) output voltage will hold turned OFF.

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Absolute Maximum Ratings(Ta=25°C)

Parameter

Symbol

Rating

Unit

VCC Voltage

VCC

PVCC

-0.3 to +7 ^{(Note 1)}

-0.3 to +7

PVCC Voltage

EN Voltage

SW, ITH Voltage

SW,ITH

Pd1

-0.3 to +7

Power Dissipation 1

Power Dissipation 2

Operating Temperature Range

Storage Temperature Range

387.5 ^{(Note 2)}

587.4 ^{(Note 3)}

-25 to +85

-55 to +150

+150

°C

Pd2

Topr

Tstg

EN Voltage

Tjmax

(Note 1) Pd should not be exceeded.

(Note 2) Derating in done 3.1mW/℃ for temperatures above Ta=25℃

(Note 3) Derating in done 4.7mW/℃ for temperatures above Ta=25℃,Mounted on 70mm×70mm×1.6mm Glass Epoxy PCB.

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=25°C)

Parameter

Symbol

Min

Typ

Max

Unit

VCC ^{(Note 4)}

PVCC ^{(Note 4)}

5.0

VCC voltage

PVCC voltage

EN voltage

4.5

5.5

VCC

0.8

Isw ^{(Note 4)}

SW average output current

(Note 4) Pd should not be exceeded.

Electrical Characteristics(Unless otherwise specified Ta=25°C VCC=PVCC=5V EN=VCC)

Parameter

Standby current

Symbol

Min

Typ

Max

Unit

Conditions

ISTB

ICC

250

GND

VCC

400

0.8

μA

EN=GND

Bias current

EN Low voltage

VENL

VENH

IEN

Standby mode

Active mode

VEN=5V

EN High voltage

2.0

EN input current

μA

MHz

Oscillation frequency

Pch FET ON resistance ^{(Note 5)}

Nch FET ON resistance ^{(Note 5)}

Output voltage

FOSC

RONP

RONN

VOUT

ITHSI

0.8

1.2

0.60

0.50

3.366

0.35

0.25

3.300

PVCC=5V

3.234

3.6

3.65

0.5

ITH SInk current

μA

VOUT =H

VOUT =L

ITH Source Current

UVLO threshold voltage

UVLO hysteresis voltage

Soft start time

ITHSO

VUVLO1

VUVLO2

TSS

3.8

3.9

4.0

4.2

VCC=H→L

VCC=L→H

Timer latch time

TLATCH

SCP/TSD operated

Output Short circuit

Threshold Voltage

VSCP

2.7

VOUT =H→L

(Note 5) Outgoing inspection is not done on all products

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Typical Performance Curves

Figure 11. V_OUTVS V_CC

Figure 12. V_OUTVS V_EN

Figure 13. V_OUTVS I_OUT

Figure 14. V_OUTVS Ta

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Typical Performance Curves - continued

Figure 15. Efficiency

Figure 16. fosc VS Ta

Figure 17. R_ONN, R_ONPVS Ta

Figure 18. V_ENVS Ta

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Typical Performance Curves - continued

Figure 19. I_CCVS Ta

Figure 20. fosc VS V_CC

Figure 22. SW waveform Io=10mA

Figure 21. Soft start waveform

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Typical Performance Curves - continued

Figure 23. SW waveform Io=200mA

Figure 24. Transient response

Io=100mA→600mA(10μs)

Figure 25. Transient response

Io=600mA→100mA(10μs)

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Application Example

VOUT

ITH

VCC

PVCC

VCC

RITH

CIN

①

VOUT

CITH

GND

PGND

GND

②

③

Figure 26. Board layout

For the sections drawn with heavy line, use thick conductor pattern as short as possible.

①

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

Manufacturer

Sumida

TDK

Kyocera

murata

Series

CMD6D11B

VLF5014AT-4R7M1R1

CM316X5R106K10A

GRM18 Series

Coil

4.7μH

Ceramic capacitor

Resistance

CIN

10μF

330pF

30kΩ

CITH

RITH

Rohm

MCR10 3002

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.

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Selection of Components Externally Connected

1. Selection of inductor (L)

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-VOUT)×VOUT

VCC

ΔIL=

[A]・・・(1)

L×VCC×f

Appropriate ripple current at output should be 30% more or less of

the maximum output current.

VOUT

ΔIL=0.3×IOUTmax[A]・・・(2)

(VCC-VOUT)×VOUT

[H]・・・(3)

ΔIL×VCC×f

(ΔIL: Output ripple current, and f: Switching frequency)

Figure 27. 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=3.3V, f=1MHz, ΔIL=0.3×0.8A=0.24A, for example,

(5-3.3)×3.3

=4.675μ → 4.7[μH]

0.24×5×1M

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)：

ΔVOUT=ΔIL×ESR [V]・・・(4)

VOUT

(ΔIL: Output ripple current, ESR: Equivalent series resistance of output capacitor)

ESR

*Rating of the capacitor should be determined allowing sufficient margin

against output voltage. Less ESR allows reduction in output ripple voltage.

Figure 28. 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: Soft-start time

Ilimit: Over current detection level, 2A(Typ)

TSS×(Ilimit-IOUT)

Co≦

[F]・・・(5)

VOUT

For instance, and if VOUT=3.3V, IOUT=0.8A, and TSS=1ms,

1m×(2-0.8)

Co≦

≒364 [μF]

3.3

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

VCC

sufficient to cope with high ripple current to prevent high transient voltage. The

Cin

ripple current IRMS is given by the equation (6):

√

VOUT(VCC-VOUT)

VOUT

IRMS=IOUT×

[A]・・・(6)

VCC

< Worst case > IRMS(max)

IOUT

When VCC is twice the Vout, IRMS=

If VCC=5V, VOUT=3.3V, and IOUTmax=0.8A,

√

Figure 29. Input capacitor

3.3(5-3.3)

IRMS=0.8×

=0.38[ARMS]

A low ESR 10μF/10V ceramic capacitor is recommended to reduce ESR dissipation of input capacitor for better efficiency.

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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)

2π×R_O×C_O

fp=

[Hz]

fp(Max)

Gain

[dB]

[Hz]

fz(ESR)=

fz(ESR)

2π×ESR×C_O

IOUTMin

IOUTMax

Pole at power amplifier

When the output current decreases, the load resistance Ro

increases and the pole frequency lowers.

Phase

[deg]

-90

fp(Min)=

[Hz]←with lighter load

[Hz]←with heavier load

2π×R_OMax×C_O

Figure 30. Open loop gain characteristics

fp(Max)=

2π×R_OMin×C_O

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.)

fz(Amp)

Gain

[dB]

[Hz]

2π×R_ITH×C_ITH

fz(Amp)=

Phase

[deg]

-90

Figure 31. Error amp phase compensation characteristics

Cin

VCC

VCC,PVCC

VOUT

ITH

ESR

GND,PGND

RITH

CITH

Figure 32. 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)

2π×R_ITH×C_ITH

2π×R_OMax×C_O

5. Determination of output voltage

Output

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.

ADJ

Adjustable output voltage range：1.0V to 2.5V

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.

Figure 33. Determination of output voltage

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Switching Regulator Efficiency

Efficiency ŋ may be expressed by the equation shown below:

VOUT×IOUT

Vin×Iin

POUT

η=

×100[%]=

×100[%]

POUT+PDα

Efficiency may be improved by reducing the switching regulator power dissipation factors P_Dα as follows:

Dissipation factors:

1) ON resistance dissipation of inductor and FET：PD(I²R)

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)

1)PD(I²R)=IOUT ×(RCOIL+RON) (RCOIL[Ω]：DC resistance of inductor, RON[Ω]：ON resistance of FETIOUT[A]：Output current.)

2)PD(Gate)=Cgs×f×V²(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

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.)

Power Dissipation

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.

1000

①mounted on glass epoxy PCB

θja=212.8°C/W

P=IOUT ×(RCOIL+RON)

RON=D×RONP+(1-D)×RONN

②Using an IC alone

θja=322.6°C/W

800

D：ON duty (=VOUT/VCC)

RCOIL：DC resistance of coil

①587.4mW

②387.5mW

600

RONP：ON resistance of P-channel MOS FET

RONN：ON resistance of N-channel MOS FET

IOUT：Output current

400

200

75 85 100

125

150

Ambient temperature:Ta [℃]

Figure 34. Thermal derating curve

(MSOP8)

If VCC=5V, VOUT=3.3V, RCOIL=0.15Ω, RONP=0.35Ω, RONN=0.25Ω,IOUT=0.8A, for example,

D=VOUT/VCC=3.3/5=0.66

RON=0.66×0.35+(1-0.66)×0.25

=0.231+0.085

=0.316[Ω]

P=0.8²×(0.15+0.316)

≒298[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.

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I/O equivalence circuit

・SW pin

・EN pin

VCC

PVCC

10kΩ

・ITH pin

・ADJ pin

VCC

10kΩ

ITH

ADJ

Figure 35. I/O equivalence circuit

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Operational Notes

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.

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.

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. The absolute maximum rating of the Pd stated in this specification is when

the IC is mounted on a 70mm x 70mm x 1.6mm glass epoxy board. In case of exceeding this absolute maximum

rating, increase the board size and copper area to prevent exceeding the Pd rating.

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.

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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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 A

P⁺

Parasitic

Elements

Parasitic

Elements

P Substrate

GND GND

P Substrate

GND

Parasitic

Elements

Parasitic

Elements

N Region

close-by

Figure 36. Example of monolithic IC structure

13. Ceramic Capacitor

When using a ceramic capacitor, determine the dielectric constant considering the change of capacitance with

temperature and the decrease in nominal capacitance due to DC bias and others.

14. Area of Safe Operation (ASO)

Operate the IC such that the output voltage, output current, and power dissipation are all within the Area of Safe

Operation (ASO).

15. Thermal Shutdown Circuit(TSD)

This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always

be within the IC’s 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.

16. Over Current Protection Circuit (OCP)

This IC incorporates an integrated overcurrent protection circuit that is activated when the load is shorted. This

protection circuit is effective in preventing damage due to sudden and unexpected incidents. However, the IC should

not be used in applications characterized by continuous operation or transitioning of the protection circuit.

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Ordering Information

B D 9

V M -

LBTR

Part Number

Package

FVM:MSOP8

Product class

LB for Industrial applications

Packaging and forming specification

TR: Embossed tape and reel

Marking Diagrams

MSOP8(TOP VIEW)

Part Number Marking

LOT Number

1PIN MARK

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Physical Dimension, Tape and Reel Information

Package Name

MSOP8

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Revision History

Date

Revision

Changes

10.Sep.2013

21.Feb.2014

001

002

New Release

Delete sentence “and log life cycle” in General Description and Futures.

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Notice

Precaution on using ROHM Products

(Note 1)

1. If you intend to use our Products in devices requiring extremely high reliability (such as medical equipment

aircraft/spacecraft, nuclear power controllers, etc.) and whose malfunction or failure may cause loss of human life,

bodily injury or serious damage to property (“Specific Applications”), please consult with the ROHM sales

representative in advance. Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way

responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any

ROHM’s Products for Specific Applications.

(Note1) Medical Equipment Classification of the Specific Applications

JAPAN

USA

CHINA

CLASSⅢ

CLASSⅣ

CLASSⅡb

CLASSⅢ

2. ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor

products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate

safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which

a failure or malfunction of our Products may cause. The following are examples of safety measures:

[a] Installation of protection circuits or other protective devices to improve system safety

[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure

3. Our Products are not designed under any special or extraordinary environments or conditions, as exemplified below.

Accordingly, ROHM shall not be in any way responsible or liable for any damages, expenses or losses arising from the

use of any ROHM’s Products under any special or extraordinary environments or conditions. If you intend to use our

Products under any special or extraordinary environments or conditions (as exemplified below), your independent

verification and confirmation of product performance, reliability, etc, prior to use, must be necessary:

[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents

[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust

[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,

H2S, NH3, SO2, and NO2

[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves

[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items

[f] Sealing or coating our Products with resin or other coating materials

[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of

flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning

residue after soldering

[h] Use of the Products in places subject to dew condensation

4. The Products are not subject to radiation-proof design.

5. Please verify and confirm characteristics of the final or mounted products in using the Products.

6. In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,

confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power

exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect

product performance and reliability.

7. De-rate Power Dissipation (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; if flow soldering method is preferred, please consult with the

ROHM representative in advance.

For details, please refer to ROHM Mounting specification

Notice - SS

Rev.002

Daattaasshheeeett

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 - SS

Rev.002

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

BD9109FVM-LB [ROHM]

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