BD3508EKN-E2_技术文档

TECHNICAL NOTE

High-performance Regulator IC Series for PCs

Ultra Low Dropout

Linear Regulators for PC Chipsets

BD3508EKN

● Description

The BD3508EKN ultra low-dropout linear chipset regulator operates from a very low input supply, and offers ideal

performance in low input voltage to low output voltage applications. It incorporates a built-in N-MOSFET power transistor to

minimize the input-to-output voltage differential to the ON resistance (RON=65mΩ) level. By lowering the dropout voltage in

this way, the regulator realizes high current output (Iomax=3.0A) with reduced conversion loss, and thereby obviates the

switching regulator and its power transistor, choke coil, and rectifier diode. Thus, the BD3508EKN is designed to enable

significant package profile downsizing and cost reduction. An external resistor allows the entire range of output voltage

configurations between 0.65 and 2.7V, while the NRCS (soft start) function enables a controlled output voltage ramp-up,

which can be programmed to whatever power supply sequence is required.

● Features

1) Internal high-precision reference voltage circuit(0.65V±1%)

2) Built-in VCC under voltage lock out circuit (VCC=3.80V)

3) NRCS (soft start) function reduces the magnitude of in-rush current

4) Internal Nch MOSFET driver offers low ON resistance (65mΩ typ)

5) Built-in current limit circuit(3.0A min)

6) Built-in thermal shutdown (TSD) circuit

7) Variable output (0.65～2.7V)

8) Incorporates high-power HQFN20V package: 4.2×4.2×0.9(mm)

● Applications

Notebook computers, Desktop computers, LCD-TV, DVD, Digital appliances

● Model Lineup

Oct. 2008

●Absolute Maximum Ratings

◎BD3508EKN

○Absolute Maximum Ratings(Ta=100℃)

PARAMETER

SYMBOL

VCC

VIN

RATING

6.0 *¹

UNIT

V

Input Voltage 1

Input Voltage 2

V

Enable Input Voltage

Power Dissipation 1

Ven

6.0

V

Pd1

0.5 ^*2

W

℃

Power Dissipation 2

Pd2

0.75 ^*3

1.75 ^*4

2.0 ^*5

Power Dissipation 3

Pd3

Power Dissipation 4

Pd4

Operating Temperature Range

Storage Temperature Range

Topr

Tstg

-10～+100

-55～+125

+150

Maximum Junction Temperature

Tjmax

*¹Should not exceed Pd.

*²Reduced by 4mW/℃ for each increase in Ta≧25℃(no heat sink)

3

*

Reduced by 6mW/℃ for each increase in Ta≧25℃ (when mounted on a 70mm×70mm×1.6mm glass-epoxy board,

with no copper foil on the bottom surface)

⁴Reduced by 14mW/℃ for each increase in Ta≧25℃ (when mounted on a 70mm×70mm×1.6mm glass-epoxy board,

with 60mm X 60 mm copper foil on the bottom surface…1-layer)

⁵Reduced by 16mW/℃ for each increase in Ta≧25℃ (when mounted on a 70mm×70mm×1.6mm glass-epoxy board,

with 60mm X 60 mm copper foil on the bottom surface…2-layer)

●Operating Conditions

○Operating Voltage(Ta=25℃)

PARAMETER

SYMBOL

VCC

MIN.

4.3

MAX.

5.5

UNIT

V

Input Voltage 1

Input Voltage 2

VIN

0.75

VFB

-0.3

VCC-1 *⁶

V

Output Voltage Setting Range

Enable Input Voltage

NRCS Capacity

Vo

2.7

V

Ven

5.5

V

CNRCS

0.001

1

uF

*⁶VCC and VIN do not have to be implemented in the order listed.

★This product is not designed for use in radioactive environments.

●Electrical Characteristics (Unless otherwise specified, Ta=25℃ VCC=5V Ven=3V VIN=1.8V R1=3.9KΩ R2=3.3KΩ)

Limit

Parameter

Bias Current

Symbol

Unit

Condition

Min.

Typ.

Max.

ICC

IST

-

0.7

1.4

mA

uA

V

VCC Shutdown Mode Current

Output Voltage

0

10

-

Ven=0V

Vo=0V

VOUT

Io

-

1.200

Maximum Output Current

Output Short Circuit Current

Output Voltage Temperature

Coefficient

3.0

-

A

Iost

-

A

Tcvo

VFB1

VFB2

-

0.01

0.650

-

%/℃

V

Feedback Voltage 1

0.643

0.630

0.657

0.670

Io=0 to 3A

Feedback Voltage 2

V

7

Ta=-10 to 100℃

*

Line Regulation 1

Line Regulation 2

Load Regulation

Minimum Input-Output Voltage

Differential

Reg.l1

Reg.l2

Reg.L

-

0.1

0.5

10

%/V

mV

VCC=4.3V to 5.5V

VIN=1.2V to 3.3V

Io=0 to 3A

Io=1A,VIN=1.2V

dVo

-

65

-

100

-

mV

mA

7

Ta=-10 to 100℃

*

Standby Discharge Current

[ENABLE]

Iden

1

Ven=0V, Vo=1V

Enable Pin

Enhi

2

-

V

Input Voltage High

Enable Pin

Enlow

Ien

-0.2

-

0.8

10

V

Input Voltage Low

Enable Input Bias Current

[FEEDBACK]

7

uA

Ven=3V

Feedback Pin Bias Current

[NRCS]

IFB

-100

0

100

nA

NRCS Charge Current

NRCS Standby Voltage

[UVLO]

Inrcs

14

-

20

0

26

50

uA

Vnrcs=0.5V

Ven=0V

VSTB

mV

VCC Under voltage Lock out

Threshold Voltage

VCC Under voltage Lock out

Hysteresis Voltage

[AMP]

VccUVLO

Vcchys

3.5

3.8

4.1

V

VCC:Sweep-up

100

160

220

mV

VCC:Sweep-down

Gate Source Current

I_GSO

I_GSI

-

1.6

4.7

-

mA

V_FB=0, V_GATE=2.5V

Gate Sink Current

V_FB=VCC, V_GATE=2.5V

*7 Design targets

● Reference Data

Vo

50mV/div

100mV/div

45mV

3.0A

64mV

3.0A

91mV

Io

3.0A

2A/div

Io=0A→3A/3μsec

t(5μsec/div)

Io=0A→3A/3μsec

t(5μsec/div)

Io=0A→3A/3μsec

t(5μsec/div)

Fig.1 Transient response (0→3A)

Co=150μF×2

Fig.2 Transient response (0→3A)

Co=150μF

Fig.3 Transient response (0→3A)

Co=47μF

Vo

55mV

87mV

79mV

50mV/div

100mV/div

Io

3.0A

2A/div

3.0A

Io=3A→0A/3μsec

t(5μsec/div)

Io=3A→0A/3μsec

t(5μsec/div)

Io=3A→0A/3μsec

t(5μsec/div)

Fig.4 Transient response (3→0A)

Co=150μF×2

Fig.5 Transient response (3→0A)

Co=150μF

Fig.6 Transient response (3→0A)

Co=47μF

Ven

VCC

2V/div

Ven

VNRCS

2V/div

VNRCS

2V/div

VIN

Vo

1V/div

t(200μsec/div)

t(2msec/div)

VCC→VIN→Ven

Fig.7 Waveform at output start

Fig.8 Waveform at output OFF

Fig.9 Input sequence

VCC

Ven

VCC

Ven

VCC

Ven

VIN

Vo

VIN

Vo

VIN

Vo

VIN→VCC→Ven

Ven→VCC→VIN

VCC→Ven→VIN

Fig.10 Input sequence

Fig.12 Input sequence

Fig.11 Input sequence

1.25

1.23

1.21

1.19

1.17

1.15

VCC

Ven

VCC

Ven

VIN

Vo

VIN

Vo

VIN→Ven→VCC

Ven→VIN→VCC

100

90

-10

10

30

50

70

Ta(℃)

Fig.15 Ta-Vo (Io=0mA)

Fig.14 Input sequence

Fig.13 Input sequence

1.00

0.95

0.90

0.85

0.80

0.75

0.70

0.65

0.60

0.55

0.50

1.2

1

2

1.9

1.8

1.7

1.6

1.5

1.4

1.3

1.2

1.1

1

0.8

0.6

0.4

0.2

0

-60 -30

0

30

60

90 120 150

-10

10

30

50

70

90

100

-10

10

30

50

70

90

100

Ta(℃)

Fig.16 Ta-ICC

Fig.17 Ta-ISTB

Fig.18 Ta-IIN

20

15

10

5

25

24

23

22

21

20

19

18

17

16

15

30

25

20

15

10

5

0

-5

-10

-15

-20

0

100

90

-10

10

30

50

70

-60 -30

0

30

60

90 120 150

-10

10

30

50

70

90

100

Ta(℃)

Fig.21 Ta-IFB

Fig.20 Ta-INRCS

Fig.19 Ta-IINSTB

60

50

40

30

20

10

0

60

55

50

45

40

35

30

25

10

9

8

7

6

5

4

3

2

1

0

2.5V

1.8V

1.2V

4

-10

10

30

50

70

90

-10

10

30

50

70

90

2

6

8

100

Ta(

)

℃

Ta(℃)

Vcc(V)

Fig.22 Ta-Ien

Fig.23 Ta-RON

(VCC=5V/Vo=1.2V)

Fig.24 VCC-RON

● Block Diagram

VCC

6

VCC

VIN1

VIN2

VIN3

VCC

8

9

Current

Limit

UVLO

Enable

EN

CL

VIN

Vo

Reference

Block

7

10

VCC

CL

Vo1

16

Vo2

Vo3

17

18

EN

UVLO

TSD

R2

R1

Thermal

FB

19

Shutdown

GATE

11

NRCS

TSD

20

2

1

NRCS

GND

● Pin Function Table

● Pin Layout

No.

1

PIN Function

Name

GND1

GND2

N.C.

VCC

EN

Ground pin 1

N.C N.C N.C N.C

GATE

11

2

Ground pin 2

15

14

13

12

3

No connection (empty) pin

Power supply pin

4

5

16

17

18

19

20

10

Vo1

Vo2

Vo3

FB

VIN3

VIN2

VIN1

EN

6

7

Enable input pin

9

8

7

6

8

VIN1

VIN2

VIN3

GATE

N.C.

Vo1

Input pin 1

FIN

9

Input pin 2

10

11

12

13

14

15

16

17

18

19

Input pin 3

Gate pin

No connection (empty) pin

Output voltage pin 1

Output voltage pin 2

Output voltage pin 3

NRCS

VCC

1

2

3

4

5

Vo2

GND1 GND2 N.C

N.C N.C

Vo3

FB

Reference voltage feedback pin

In-rush current protection (NRCS)

capacitor connection pin

20

NRCS

FIN

reverse

Connected to heatsink and GND

* Please short N.C to the GND

● Operation of Each Block

・AMP

This is an error amp that functions by comparing the reference voltage (0.65V) with Vo to drive the output Nch FET

(Ron=65mΩ). Frequency optimization helps to realize rapid transit response, and to support the use of functional polymer

output capacitors. AMP input voltage ranges from GND to 2.7V, while the AMP output ranges from GND to VCC. When EN

is OFF, or when UVLO is active, output goes LOW and the output NchFET switches OFF.

・EN

The EN block controls the regulator ON/OFF pin by means of the logic input pin. In OFF position, circuit voltage is

maintained at 0μA, thus minimizing current consumption at standby. The FET is switched ON to enable discharge of the

NRCS pin Vo, thereby draining the excess charge and preventing the load IC from malfunctioning. Since no electrical

connection is required (such as between the VCC pin and the ESD prevention Di), module operation is independent of the

input sequence.

・UVLO

To prevent malfunctions that can occur when there is a momentary decrease in VCC supply voltage, the UVLO circuit

switches output OFF, and, like the EN block, discharges the NRCS Vo. Once the UVLO threshold voltage (TYP3.80V) is

exceeded, the power-on reset is triggered and output begins.

・CURRENT LIMIT

With output ON, the current limit function monitors internal IC output current against the parameter value (3.0A). When

current exceeds this level, the current limit module lowers the output current to protect the load IC. When the overcurrent

state is eliminated, output voltage is restored at the parameter value.

・NRCS

The soft start function is realized by connecting an NRCS pin external capacitor to the target ground. Output ramp-up can

be set for any period up to the time the NRCS pin reaches VFB (0.65V). During startup, the NRCS pin serves as the 20μA

(TYP) constant current source and charges the externally connected capacitor.

・TSD (Thermal Shut Down)

The shutdown (TSD) circuit automatically switches output OFF when the chip temperature gets too high, thus serving to

protect the IC against “thermal runaway” and heat damage. Because the TSD circuit is provided to shut down the IC in the

presence of extreme heat, in order to avoid potential problems with the TSD, it is crucial that the Tj (max) parameter not be

exceeded in the thermal design.

・VIN

The VIN line is the major current supply line, and is connected to the output NchFET drain. Since no electrical connection

(such as between the VCC pin and an ESD protective Di) is necessary, VIN operates independent of the input sequence.

However, since there is an output NchFET body Di between VIN and Vo, a VIN-Vo electric (Di) connection is present. Note,

therefore, that when output is switched ON or OFF, reverse current may flow to the VIN from Vo.

●Timing Chart

EN ON/OFF

VIN

VCC

Ven

0.65V(typ)

NRCS

Vo

Startup

t

VCC ON/OFF

VIN

VCC

Ven

UVLO

Hysteresis

0.65V(typ)

NRCS

Vo

Startup

t

●Evaluation Board

■ BD3508EKN Evaluation Board Schematic

■ BD3508EKN Evaluation Board Standard Component List

Component Rating Manufacturer Product Name

U1

-

ROHM

BD3508EKN

MCH184CN105K

MCH185CN103K

Jumper

C5

C4

R1

R2

47uF

10uF

3.9k

ROHM

MCH318CN476K

MCH218CN106K

MCR03EZPF3301

MCR03EZPF3901

C1

1uF

C10

R8

0.01uF ROHM

0Ω

-

3.3k

■ BD3508EKN Evaluation Board Layout

Silkscreen

Bottom Layer

TOP Layer

● Recommended Circuit Example

Option

R3

C5

15

14

13

12

11

Vo (1.2V/3A)

C3

16

17

18

19

20

10

9

C2

VIN

R2

8

7

R1

VEN

6

C4

C1

VCC

1

2

3

4

5

Recommended

Component

R1/R2

Programming Notes and Precautions

Value

3.9k/3.3k

IC output voltage can be set with a configuration formula using the values for the internal

reference output voltage (V_FB)and the output voltage resistors (R1, R2). Select resistance

values that will avoid the impact of the V_FBcurrent (±100nA). The recommended total

resistance value is 10KΩ.

C3

47μF

To assure output voltage stability, please be certain the Vo1, Vo2, and Vo3 pins and the

GND pins are connected. Output capacitors play a role in loop gain phase compensation

and in mitigating output fluctuation during rapid changes in load level. Insufficient

capacitance may cause oscillation, while high equivalent series reisistance (ESR) will

exacerbate output voltage fluctuation under rapid load change conditions. While a 47μF

ceramic capacitor is recomended, actual stability is highly dependent on temperature and

load conditions. Also, note that connecting different types of capacitors in series may

result in insufficient total phase compensation, thus causing oscillation. In light of this

information, please confirm operation across a variety of temperature and load

conditions.

C1

1μF

10μF

0.01μF

-

Input capacitors reduce the output impedance of the voltage supply source connected to

the (VCC) input pins. If the impedance of this power supply were to increase, input

voltage (VCC) could become unstable, leading to oscillation or lowered ripple rejection

function. While a low-ESR 1μF capacitor with minimal susceptibility to temperature is

recommended, stability is highly dependent on the input power supply characteristics and

the substrate wiring pattern. In light of this information, please confirm operation across a

variety of temperature and load conditions.

C2

Input capacitors reduce the output impedance of the voltage supply source connected to

the (VCC) input pins. If the impedance of this power supply were to increase, input

voltage (VCC) could become unstable, leading to oscillation or lowered ripple rejection

function. While a low-ESR 10μF capacitor with minimal susceptibility to temperature is

recommended, stability is highly dependent on the input power supply characteristics and

the substrate wiring pattern. In light of this information, please confirm operation across a

variety of temperature and load conditions.

C4

The Non Rush Current on Startup (NRCS) function is built into the IC to prevent rush

current from going through the load (VIN to Vo) and impacting output capacitors at power

supply start-up. Constant current comes from the NRCS pin when EN is HIGH or the

UVLO function is deactivated. The temporary reference voltage is proportionate to time,

due to the current charge of the NRCS pin capacitor, and output voltage start-up is

proportionate to this reference voltage. Capacitors with low susceptibility to temperature

are recommended, in order to assure a stable soft-start time.

R3/C5

This component is employed when the C3 capacitor causes, or may cause, oscillation. It

provides more precise internal phase correction.

● Heat Loss

Thermal design should allow operation within the following conditions. Note that the temperatures listed are the allowed

temperature limits, and thermal design should allow sufficient margin from the limits.

1. Ambient temperature Ta can be no higher than 100 ℃.

2. Chip junction temperature (Tj) can be no higher than 150℃.

Chip junction temperature can be determined as follows:

① Calculation based on ambient temperature (Ta)

Tj=Ta+θj-a×W

＜Reference values＞

θj-a:HQFN20V 250.0℃/W Bare (unmounted) IC

166.7℃/W 1-layer substrate (top layer copper foil less than 3%)

71.4℃/W 1-layer substrate (bottom layer surface copper foil area 60×60mm²)

62.5℃/W 2-layer substrate (top layer copper foil area 60×60mm²)

Substrate size: 70×70×1.6mm³(substrate with thermal via)

It is recommended to layout the VIA for heat radiation in the GND pattern of reverse (of IC) when there is the GND pattern in

the inner layer (in using multiplayer substrate). This package is so small (size: 4.2mm×4.2mm) that it is not available to

layout the VIA in the bottom of IC. Spreading the pattern and being increased the number of VIA like the figure below).

enable to get the superior heat radiation characteristic. (This figure is the image. It is recommended that the VIA size and

the number is designed suitable for the actual situation.).

Most of the heat loss that occurs in the BD3508EKN is generated from the output Nch FET. Power loss is determined by

the total VIN-Vo voltage and output current. Be sure to confirm the system input and output voltage and the output current

conditions in relation to the heat dissipation characteristics of the VIN and Vo in the design. Bearing in mind that heat

dissipation may vary substantially depending on the substrate employed (due to the power package incorporated in the

BD3508EKN) make certain to factor conditions such as substrate size into the thermal design.

Power consumption (W) = Input voltage (VIN)- output voltage (Vo) ×Io (Ave)

Example) VIN=1.5V, Vo=1.2V, Io(Ave) = 3A

Power consumption (W) =

= 0.9(W)

1.5(V)-1.2(V) ×3.0(A)

● Input-Output Equivalent Circuit Diagram

VCC

1kΩ

VIN1

VIN2

VIN3

NRCS

1kΩ

10kΩ

1kΩ

VCC

1kΩ

EN

FB

1kΩ

VO1

350kΩ

100kΩ

1kΩ

VO2

VO3

50kΩ

100kΩ

10kΩ

20pF

●Reference landing pattern

thermal via

b2

E3

e

MIE

L2

(Unit : mm)

Lead pitch

landing pitch

landing length

landing pitch

e

MIE

2.60

≧l2

1.10

b2

0.50

0.25

central pad length

central pad pitch

thermal via

D3

E3

Diameter

1.60

Φ0.30

*It is recommended to design suitable for the actual application.

●Operation Notes

1. Absolute maximum ratings

An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc., can

break down the devices, thus making impossible to identify breaking mode, such as a short circuit or an open circuit. If any

over rated values will expect to exceed the absolute maximum ratings, consider adding circuit protection devices, such as

fuses.

2. Connecting the power supply connector backward

Connecting of the power supply in reverse polarity can damage IC. Take precautions when connecting the power supply

lines. An external direction diode can be added.

3. Output pin

In the event that load containing a large inductance component is connected to the output terminal, and generation of

back-EMF at the start-up and when output is turned OFF is assumed, it is requested to insert a protection diode.

(Example)

OUTPUT PIN

4. GND voltage

The potential of GND pin must be minimum potential in all operating conditions.

5. Thermal design

Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating conditions.

6. Inter-pin shorts and mounting errors

Use caution when positioning the IC for mounting on printed circuit boards. The IC may be damaged if there is any

connection error or if pins are shorted together.

7. Actions in strong electromagnetic field

Use caution when using the IC in the presence of a strong electromagnetic field as doing so may cause the IC to

malfunction.

8. ASO

When using the IC, set the output transistor so that it does not exceed absolute maximum ratings or ASO.

9. Thermal shutdown circuit

The IC incorporates a built-in thermal shutdown circuit (TSD circuit). The thermal shutdown circuit (TSD circuit) is designed

only to shut the IC off to prevent thermal runaway. It is not designed to protect the IC or guarantee its operation. Do not

continue to use the IC after operating this circuit or use the IC in an environment where the operation of this circuit is

assumed.

TSD on temperature [°C] (typ.)

175

Hysteresis temperature [°C] (typ.)

15

BD3508EKN

10. Testing on application boards

When testing the IC on an application board, connecting a capacitor to a pin with low impedance subjects the IC to stress.

Always discharge capacitors after each process or step. Always turn the IC's power supply off before connecting it to or

removing it from a jig or fixture during the inspection process. Ground the IC during assembly steps as an antistatic

measure. Use similar precaution when transporting or storing the IC.

11. Regarding 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 these P layers with the N layers of other elements, creating a parasitic diode

or transistor. For example, the relation between each potential is as follows:

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 can occur inevitable in the structure of the IC. The operation of parasitic diodes can result in mutual

interference among circuits, operational faults, or physical damage. Accordingly, methods by which parasitic diodes

operate, such as applying a voltage that is lower than the GND (P substrate) voltage to an input pin, should not be used.

Resistor

Transistor (NPN)

B

Pin A

Pin B

C

E

Pin A

B

C

E

N

P⁺

N

P

Parasitic

element

N

Parasitic

element

P substrate

GND

Parasitic element

Other adjacent elements

12. Ground Wiring Pattern

When using both small signal and large current GND patterns, it is recommended to isolate the two ground patterns, placing

a single ground point at the ground potential of application so that the pattern wiring resistance and voltage variations

caused by large currents do not cause variations in the small signal ground voltage. Be careful not to change the GND

wiring pattern of any external components, either.

● Heat Dissipation Characteristics

◎HQFN20V

[W]

2.5

(1) IC unit

θj-a=250℃/W

(4) 2.0W

(2) Substrate (Bottom surface copper foil area: none)

θj-a=166.7℃/W

(3) Substrate (Bottom surface copper foil area: 60mm×

60mm…1 layer)

θj-a=71.4℃/W

(4) Substrate (Bottom surface copper foil area: 60mm×

60mm…2 layers)

2.0

1.5

1.0

(3) 1.75W

θj-a=62.5℃/W

(2) 0.75W

(1) 0.5W

0.5

0

25

50

75

100

125 150

[℃]

Ambient Temperature [Ta]

● Type Designations (Ordering Information)

B

D

3

5

0

8

E

K

N

-

E

2

Product Name

Package Type

・EKN : HQFN20V

E2 Emboss tape reel opposite draw-out side: 1 pin

・BD3508

● Package specification

HQFN20V

Packing Specs

External View

Embossed tape (moisture-proof packing)

2500pcs

Packing

(2.1)

0.5

4.2 0.1

4.0 0.1

Pieces/Reel

(1.1)

15

11

E2

Unreeling

Direction

16

10

6

(0.22)

(With reel in left hand, unreeling with the right, the index

[number 1] pin is at the top left)

20

3

−

1

5

(0.35)

0.22 0.05

0.6₋⁺₀⁰_.^.₃¹

0.05

(0.5)

0.05

Draw-out side

#1 Pin

Reel

(Unit: mm)

Note: Please order by the number of reels desired

Daattaasshheeeett

Notice

Precaution on using ROHM Products

1. Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,

OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you

intend to use our Products in devices requiring extremely high reliability (such as medical equipment ^{(Note 1)}, transport

equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car

accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or

serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.

Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any

damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific

Applications.

(Note1) Medical Equipment Classification of the Specific Applications

JAPAN

USA

EU

CHINA

CLASSⅢ

CLASSⅣ

CLASSⅡb

CLASSⅢ

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

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

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

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

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

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

3. Our Products are designed and manufactured for use under standard conditions and not under any special or

extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way

responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any

special or extraordinary environments or conditions. If you intend to use our Products under any special or

extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of

product performance, reliability, etc, prior to use, must be necessary:

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

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

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

H2S, NH3, SO2, and NO2

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

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

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

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

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

residue after soldering

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

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

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

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

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

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

product performance and reliability.

7. De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual

ambient temperature.

8. Confirm that operation temperature is within the specified range described in the product specification.

9. ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in

this document.

Precaution for Mounting / Circuit board design

1. When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product

performance and reliability.

2. In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the

ROHM representative in advance.

For details, please refer to ROHM Mounting specification

Notice - GE

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 - GE

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


型号：	BD3508EKN-E2
厂家：	ROHM
描述：	Adjustable Positive LDO Regulator, 0.65V Min, 2.7V Max, 4.20 X 4.20 MM, 0.90 MM HEIGHT, ROHS COMPLIANT, HQFN-20 输出元件调节器
文件：	总18页 (文件大小：1028K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

BD3508EKN-E2 [ROHM]

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