BD3508MUV_技术文档

High-performance Regulator IC Series for PCs

Ultra Low Dropout

Linear Regulators for PC Chipsets

No.09030EAT22

BD3508MUV, BD3509MUV

● Description

The BD3508MUV / BD3509MUV 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 MAX=100mΩ/50mΩ) level. By

lowering the dropout voltage in this way, the regulator realizes high current output (Iomax=3.0A/4.0A) with reduced

conversion loss, and thereby obviates the switching regulator and its power transistor, choke coil, and rectifier diode. Thus,

the BD3508MUV / BD3509MUV are 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/28mΩ typ)

5) Built-in current limit circuit (3.0A/4.0A min)

6) Built-in thermal shutdown (TSD) circuit

7) Variable output (0.65～2.7V)

8) Incorporates high-power VQFN020V4040 package: 4.0×4.0×1.0(mm)

9) Tracking function

● Applications

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

● Model Lineup

Maximum output current

Package

VCC=5V

3A

4A

BD3508MUV

BD3509MUV

VQFN020V4040

www.rohm.com

2009.05 - Rev.A

1/20

c

Technical Note

BD3508MUV, BD3509MUV

●Absolute Maximum Ratings (Ta=100℃)

BD3508MUV / BD3509MUV

Limit

BD3508MUV BD3509MUV

Parameter

Symbol

Unit

Input Voltage 1

VCC

VIN

6.0 *¹

V

Input Voltage 2

Input Voltage 3

VDD

Ven

-

6.0*¹

6.0

V

Enable Input Voltage

Power Good Input Voltage

Power Dissipation 1

Power Dissipation 2

Power Dissipation 3

Power Dissipation 4

Operating Temperature Range

Storage Temperature Range

6.0

V

V_PGOOD

Pd1

V

0.34 ^*2

0.70 ^*3

1.21 ^*4

3.56 ^*5

W

℃

Pd2

Pd3

Pd4

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)

*³1 layer, mounted on a board 74.2mm×74.2mm×1.6mm Glass-epoxy PCB (Copper foil area : 10.29mm²)

*⁴4 layers, mounted on a board 74.2mm×74.2mm×1.6mm Glass-epoxy PCB (Copper foil area : 10.29mm²) , copper foil in each layers.

*⁵4 layers, mounted on a board 74.2mm×74.2mm×1.6mm Glass-epoxy PCB (Copper foil area : 5505mm²) , copper foil in each layers.

●Operating Conditions(Ta=25℃)

BD3508MUV

BD3509MUV

Parameter

Input Voltage 1

Symbol

Unit

Min

Max

Min

Max

VCC

VIN

4.3

0.75

-

5.5

4.3

0.7

5.5

V

Input Voltage 2

VCC-1 *⁶

5.5

Input Voltage 3

VDD

Vo

-

2.7

V

Output Voltage setting Range

Enable Input Voltage

NRCS capacity

VFB

-0.3

0.001

2.7

5.5

1

VFB

-0.3

0.001

2.7

V

Ven

5.5

V

CNRCS

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.

www.rohm.com

2009.05 - Rev.A

2/20

c

Technical Note

BD3508MUV, BD3509MUV

●Electrical Characteristics

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

◎BD3508MUV

Limit

Typ.

0.7

0

Parameter

Symbol

Unit

Condition

Min.

Max.

Bias Current

ICC

IST

Vo

-

1.4

mA

uA

V

VCC Shutdown Mode Current

Output Voltage

10

-

Ven=0V

Vo=0V

-

1.200

-

Maximum Output Current

Output Short Circuit Current

Output Voltage Temperature

Coefficient

Io

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

Tj=-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

Tj=-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 Guarantee

www.rohm.com

2009.05 - Rev.A

3/20

c

Technical Note

BD3508MUV, BD3509MUV

●Electrical Characteristics

(Unless otherwise specified, Ta=25℃ VCC=5V Ven=3V VIN=1.5V VDD=3.3V R1=3.9KΩ R2=3.6KΩ)

◎BD3509MUV

Limit

Typ.

1.1

0

Parameter

Symbol

Unit

Condition

Min.

Max.

2.0

10

-

Bias Current

ICC

IST

Vo

-

mA

uA

V

VCC Shutdown Mode Current

Output Voltage

Ven=0V

-

1.25

-

Maximum Output Current

Output Voltage Temperature

Coefficient

Io

4.0

-

A

Tcvo

VFB1

VFB2

-

0.01

0.650

-

%/℃

V

Feedback Voltage 1

0.643

0.637

0.657

0.663

Io=0 to 4A

Feedback Voltage 2

V

7

Tj=-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 4A

Io=1A,VIN=1.25V

dVo

-

28

-

50

-

mV

mA

7

Tj=-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

-

10

18

-

mA

V_FB=0, V_GATE=2.5V

Gate Sink Current

[PGOOD Block]

Threshold voltage

V_FB=VCC, V_GATE=2.5V

V_THPG

R_PG

-

0.585

0.1

-

V

FB voltage

Ron

kΩ

*7 Design Guarantee

www.rohm.com

2009.05 - Rev.A

4/20

c

Technical Note

BD3508MUV, BD3509MUV

●Reference Data

BD3508MUV

Vo

50mV/div

45mV

50mV/div

100mV/div

64mV

3.0A

91mV

Io

3.0A

3A

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)

Fig.2 Transient Response

(0→3A)

Fig.3 Transient Response

(0→3A)

Co=150μF×2, CFB=0.01uF

Co=150μF

Co=47μF, CFB=0.01uF

Vo

55mV

79mV

87mV

50mV/div

100mV/div

Io

3.0A

2A/div

3.0A

3A

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)

Fig.5 Transient Response

(3→0A)

Fig.6 Transient Response

(3→0A)

Co=150μF×2

Co=150μF

Co=47μF

Ven

VCC

Ven

2V/div

VNRCS

2V/div

VNRCS

2V/div

VIN

Vo

1V/div

t(200μsec/div)

t(2msec/div)

VCC→VIN→Ven

Fig.9 Input sequence

Fig.7: Waveform at output start

Fig.8 Waveform at output OFF

VCC

Ven

VCC

Ven

VIN

Vo

VIN

Vo

VIN

Vo

VIN→VCC→Ven

Ven→VCC→VIN

VCC→Ven→VIN

Fig.10 Input sequence

Fig.11 Input sequence

Fig.12 Input sequence

www.rohm.com

2009.05 - Rev.A

5/20

c

Technical Note

BD3508MUV, BD3509MUV

●Reference Data

1.25

1.23

1.21

1.19

1.17

1.15

VCC

Ven

VIN

VCC

Ven

VIN

Vo

VIN→Ven→VCC

Ven→VIN→VCC

-10

10

30

50

70

90

100

Ta(

)

℃

Fig.13 Input sequence

Fig.14 Input sequence

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

1.00

0.95

0.90

0.85

0.80

0.75

0.70

0.65

0.60

0.55

0.50

2.0

1.9

1.8

1.7

1.6

1.5

1.4

1.3

1.2

1.1

1.0

1.2

1.0

0.8

0.6

0.4

0.2

0.0

100

90

100

90

-10

10

30

50

70

-10

10

30

50

70

-60 -30

0

30 60

90 120 150

Ta(℃)

Fig.16 Tj-ICC

Fig.17 Tj-ISTB

Fig.18 Tj-IIN

25

24

23

22

21

20

19

18

17

16

15

20

15

10

5

30

25

20

15

10

5

0

-5

-10

-15

-20

0

100

-10

10

30

50

70

90

100

90

-10

10

30

50

70

-60 -30

0

30

60

90 120 150

Ta(

)

℃

Ta(℃)

Fig.21 Tj-IFB

Fig.20 Tj-INRCS

Fig.19 Tj-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

100

-10

10

30

50

70

90

2

6

8

-10

10

30

50

70

90 100

Ta(℃)

Vcc(V)

Ta(℃)

Fig.24 Vcc-RON

Fig.22 Tj-Ien

Fig.23 Tj-RON

(Vcc=5V/Vo=1.2V)

www.rohm.com

2009.05 - Rev.A

6/20

c

Technical Note

BD3508MUV, BD3509MUV

●Reference Data

BD3509MUV

Vo

50mV/div

100mV/div

41mV

39mV

51mV

Io

2A/div

4.0A

Io=0A→4A/4μsec t(10μsec/div)

Io=0A→4A/4μsec

t(10μsec/div)

Io=0A→4A/4μsec

t(10μsec/div)

Fig.25 Transient Response

(0→4A)

Fig.26 Transient Response

(0→4A)

Fig.27 Transient Response

(0→4A)

Co=22μF

Co=100μF

Co=47μF

37mV

Vo

41mV

39mV

50mV/div

Io

2A/div

4.0A

Io

2A/div

4.0A

Io=4A→0A/4μsec t(100μsec/div)

Fig.28 Transient Response

(4→0A)

Fig.29 Transient Response

(4→0A)

Fig.30 Transient Response

(4→0A)

Co=22μF, C_FB=0.01μF

Co=100μF

Co=47μF, C_FB=0.01μF

VEN

VCC

2V/div

VNRCS

1V/div

VNRCS

1V/div

Vo

VIN

Vo

1V/div

PGOOD

2V/div

t(200μsec/div)

t(2msec/div)

VCC→VIN→VEN

Fig.33 Input sequence

Fig.31: Waveform at output start

Fig.32 Waveform at output

OFF

VEN

VCC

VIN

VEN

VCC

VEN

VCC

VIN

Vo

VIN

Vo

VIN→VCC→VEN

VEN→VCC→VIN

VCC→VEN→VIN

Fig.34 Input sequence

Fig.35 Input sequence

Fig.36 Input sequence

www.rohm.com

2009.05 - Rev.A

7/20

c

Technical Note

BD3508MUV, BD3509MUV

●Reference Data

1.3

1.29

1.28

1.27

1.26

1.25

1.24

1.23

1.22

1.21

1.2

VEN

VCC

VIN

VEN

VCC

VIN

Vo

-50 -25

0

25 50 75 100 125 150

Ta(℃)

VIN→VEN→VCC

VEN→VIN→VCC

Fig.37 Input sequence

Fig.38 Input sequence

Fig.39 Tj-Vo (Io=0mA)

1.5

1.2

0.9

0.6

0.3

0

1

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

50

45

40

35

30

25

20

15

10

5

0

-50 -25

0

25 50 75 100 125 150

Ta(℃)

-50 -25

0

25 50 75 100 125 150

Ta(℃)

-50 -25

0

25 50 75 100 125 150

Ta(℃)

Fig.40 Tj-ICC

Fig.41 Tj-ISTB

Fig.42 Tj-IDD

0.1

2

1.8

1.6

1.4

1.2

1

50

45

40

35

30

25

20

15

10

5

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

0

-50 -25

0

25 50 75 100 125 150

Ta(℃)

-50 -25

0

25 50 75 100 125 150

Ta(℃)

-50 -25

0

25 50 75 100 125 150

Ta(℃)

Fig.43 Tj-IDDSTB

Fig.44 Tj-IIN

Fig.45 Tj-IINSTB

25

24

23

22

21

20

19

18

17

16

15

10

8

9

8

7

6

5

4

3

2

1

0

6

4

2

0

-2

-4

-6

-8

-10

-50 -25

0

25 50 75 100 125 150

Ta(℃)

-50 -25

0

25 50 75 100 125 150

Ta(℃)

-50 -25

0

25 50 75 100 125 150

Ta(℃)

Fig.47 Tj-IFB

8/20

Fig.46 Tj-INRCS

Fig.48 Tj-Ien

www.rohm.com

2009.05 - Rev.A

c

Technical Note

BD3508MUV, BD3509MUV

●Reference Data

50

45

40

35

30

25

20

15

10

5

50

45

40

35

30

25

2.5V

1.8V

1.25V

4

1.0V

5

0

-50 -25

0

25 50 75 100 125 150

4.3

5.5

Ta(℃)

VCC[V]

Fig.50 Vcc-RON

Fig.49 Tj-RON

(Vcc=5V/Vo=1.2V)

●Block Diagram

BD3508MUV

VCC

6

VIN1

8

9

VCC

UVLO

VIN2

VIN3

VIN

Current

Limit

CL

EN

Reference

Block

7

10

VCC

Vo1

Vo2

Vo3

16

17

18

Vo

CL

UVLO

TSD

EN

FB

Thermal

Shutdown

19

11

GATE

NRCS

20

TSD

1

2

NRCS

GND

BD3509MUV

VCC

6

VIN1

VIN2

8

9

VCC

VIN

VIN3

VIN4

VIN5

Current

Limit

UVLO

CL

10

12

13

EN

Reference

Block

7

VCC

VDD

5

Vo1

Vo2

Vo3

Vo4

Vo5

VCC

14

15

16

17

Vo

CL

UVLO

TSD

PGOOD

4

POWER

GOOD

18

EN

FB

19

Thermal

Shutdown

GATE

NRCS

20

11

TSD

1

2

NRCS

GND

www.rohm.com

2009.05 - Rev.A

9/20

c

Technical Note

BD3508MUV, BD3509MUV

●Pin Layout

BD3508MUV

BD3509MUV

Vo2 Vo1 VIN5

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

GATE

11

VIN4

12

GATE

11

15

14

13

12

15

14

13

16

17

18

19

20

10

9

16

17

18

19

20

10

Vo1

Vo2

Vo3

FB

Vo3

Vo4

Vo5

FB

VIN3

VIN2

VIN1

EN

VIN3

9

VIN2

FIN

8

VIN1

7

EN

6

NRCS

VCC

NRCS

VCC

1

2

3

4

5

1

2

3

4

5

GND1 GND2 N.C

N.C N.C

GND1 GND2 N.C PGOOD VDD

●Pin Function Table

BD3508MUV

BD3509MUV

PIN Name

PIN Function

PIN Name

PIN Function

Ground pin 1

No.

1

No.

1

GND1

GND2

N.C.

VCC

EN

Ground pin 1

Ground pin 2

GND1

GND2

N.C.

PGOOD

VDD

VCC

EN

2

Ground pin 2

3

No connection (empty) pin *

Power supply pin

3

No connection (empty) pin *

Power Good pin

4

5

Power supply pin

Enable input pin

6

7

Enable input pin

7

8

VIN1

VIN2

VIN3

GATE

N.C.

Vo1

Input pin 1

8

VIN1

VIN2

VIN3

GATE

VIN4

VIN5

Vo1

Input pin 1

9

Input pin 2

9

Input pin 2

10

11

12

13

14

15

16

17

18

19

Input pin 3

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

Input pin 4

Input pin 5

Output voltage pin 1

Output voltage pin 2

Output voltage pin 3

Output voltage pin 4

Output voltage pin 5

Reference voltage feedback pin

In-rush current protection (NRCS)

capacitor connection pin

Vo2

Vo3

Vo2

Vo4

Vo3

Vo5

FB

Reference voltage feedback pin

In-rush current protection (NRCS)

capacitor connection pin

FB

20

NRCS

FIN

20

NRCS

FIN

rever

se

rever

se

Connected to heatsink and GND

* Please short N.C to the GND。

* Please short N.C to the GND

www.rohm.com

2009.05 - Rev.A

10/20

c

Technical Note

BD3508MUV, BD3509MUV

●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=50mΩ). 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. 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.

・PGOOD (BD3509MUV)

This is the monitor pin for output voltage (Vo). It is used through the pull-up resistance (100kΩ). PGOOD pin judges the

voltage High or Low (FB Voltage 0.585V typ. : threshold voltage).

www.rohm.com

2009.05 - Rev.A

11/20

c

Technical Note

BD3508MUV, BD3509MUV

●Timing Chart

VIN

VCC

EN

0.65V(typ)

NRCS

Vo

Start up

Vo×0.9V(typ)

80μs(typ)

t

PGOOD

(BD3509MUV)

VCC ON/OFF

VIN

VCC

EN

UVLO

Hysteresis

0.65V(typ)

NRCS

Vo

Start up

Vo×0.9V(typ)

80μs(typ)

t

PGOOD

(BD3509MUV)

www.rohm.com

2009.05 - Rev.A

12/20

c

Technical Note

BD3508MUV, BD3509MUV

●Evaluation Board

■ BD3509MUV Evaluation Board Schematic

■ BD3509MUV Evaluation Board Standard Component List

Component Rating Manufacturer Product Name

Component Rating

R4

Manufacturer Product Name

U1

-

ROHM

BD3509MUV

100kΩ ROHM

MCR03EZPF1003

Jumper

C5

0.1uF

1uF

10uF

22uF

MURATA

KYOCERA

GRM155F11E104ZD

GRM188B11A105KD

GRM21BB10J106KD

CM316W5R226K06AT

GRM188B11H103KD

R7

0Ω

-

C6

R8

3.6k

3.9kΩ

0Ω

ROHM

MCR03EZPF3601

MCR03EZPF3901

Jumper

C8

R9

ROHM

C16

C20

JP13

JP14

-

0.01uF MURATA

0Ω

Jumper

www.rohm.com

2009.05 - Rev.A

13/20

c

Technical Note

BD3508MUV, BD3509MUV

■ BD3509MUV Evaluation Board Layout

Silk Screen (Top)

Silk Screen (Bottom)

TOP Layer

Middle Layer_1

Middle Layer_2

Bottom Layer

●Recommended Circuit Example

Vo (1.25V/4A)

15

14

13

12

11

C8

VIN

C16

16

17

18

19

20

10

9

C18

R18

R19

8

7

VEN

6

C6

VCC

1

2

3

4

5

C20

R4

VPGOOD

C5

VDD

www.rohm.com

2009.05 - Rev.A

14/20

c

Technical Note

BD3508MUV, BD3509MUV

Recommended

Component

Value

Programming Notes and Precautions

R1/R2

3.6k/3.9k

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.

R4

100k

22uF

This is the pull-up resistance for open drain pin. It is recommended to set the value about

100kΩ.

C16

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.

C6

C8

1uF

The input capacitor reduces the output impedence of the voltage supply source connected to

the VCC. When the output impedence of this power supply increases, the input voltage

(VCC) may become unstable. This may result in the output voltage oscillation or lowering

ripple rejection. A low ESR 1uF capacitor with minimal susceptibility to temperature is

preferable, but stability depends on power supply characteristics and the substrate wiring

pattern. Please confirm operation across a variety of temperature and load conditions.

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

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

could become unstable, leading to oscillation or lowered ripple rejection function. While a

low-ESR 10uF 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.

10uF

C5

0.1uF

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

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

could become unstable, leading to oscillation or lowered ripple rejection function. While a

low-ESR 0.1uF 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.

C20

C18

0.01uF

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.

This component is employed when the C16 capacitor causes, or may cause, oscillation. It

provides more precise internal phase correction.

www.rohm.com

2009.05 - Rev.A

15/20

c

Technical Note

BD3508MUV, BD3509MUV

●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: VQFN020V4040 367.6℃/W Bare (unmounted) IC

178.6℃/W 4-layer substrate (bottom layer surface copper foil area 10.29mm²)

103.3℃/W 4-layer substrate (bottom layer surface copper foil area 10.29mm²)

35.1℃/W 4-layer substrate (top layer copper foil area 5505mm²)

Substrate size: 74.2×74.2×1.6mm³(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 BD3509MUV 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

BD3509MUV) 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=1.25V, Io(Ave) = 4A

Power consumption (W) =

1.5(V)-1.2(V) ×4.0(A)

= 1.0(W)

www.rohm.com

2009.05 - Rev.A

16/20

c

Technical Note

BD3508MUV, BD3509MUV

●Input-Output Equivalent Circuit Diagram

VCC

1kΩ

NRCS

1kΩ

VIN1

VIN2

VIN3

VIN4

GATE

1kΩ

10kΩ

1kΩ

VIN5

VCC

EN

1kΩ

FB

Vo1

350kΩ

1kΩ

100kΩ

Vo2

50kΩ

10kΩ

Vo3

Vo4

Vo5

20pF

PGOOD

www.rohm.com

2009.05 - Rev.A

17/20

c

Technical Note

BD3508MUV, BD3509MUV

●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.)

Hysteresis temperature [°C] (typ.)

BD3508MUV /

BD3509MUV

175

15

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.

www.rohm.com

2009.05 - Rev.A

18/20

c

Technical Note

BD3508MUV, BD3509MUV

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

①

②

③

4 layers (Copper foil area : 5505mm²)

copper foil in each layers.

θj-a=35.1℃/W

4 layers (Copper foil area : 10.29m²)

copper foil in each layers.

θj-a=103.3℃/W

4.0

3.0

①3.56W

4 layers (Copper foil area : 10.29m²)

θj-a=178.6℃/W

④IC only.

2.0

②1.21W

1.0

0

③0.70W

④0.34W

0

25

50

75 100105 125

150

Ambient temperature:Ta [℃]

www.rohm.com

2009.05 - Rev.A

19/20

c

Technical Note

BD3508MUV, BD3509MUV

 Ordering part number

B D

3

5

0

8

M U V

-

E

2

Part No.

3508

Package

Packaging and forming specification

E2: Embossed tape and reel

MUV: VQFN020V4040

3509

VQFN020V4040

4.0 0.1

Tape

Embossed carrier tape

2500pcs

Quantity

E2

Direction

of feed

1PIN MARK

The direction is the 1pin of product is at the upper left when you hold

reel on the left hand and you pull out the tape on the right hand

S

(

)

0.08

S

2.1 0.1

C0.2

1.0

1

5

20

16

6

10

15

11

+0.05

–0.04

Direction of feed

1pin

0.25

0.5

Reel

Order quantity needs to be multiple of the minimum quantity.

(Unit : mm)

∗

www.rohm.com

2009.05 - Rev.A

20/20

c

Notice

N o t e s

No copying or reproduction of this document, in part or in whole, is permitted without the

consent of ROHM Co.,Ltd.

The content speciﬁed herein is subject to change for improvement without notice.

The content speciﬁed herein is for the purpose of introducing ROHM's products (hereinafter

"Products"). If you wish to use any such Product, please be sure to refer to the speciﬁcations,

which can be obtained from ROHM upon request.

Examples of application circuits, circuit constants and any other information contained herein

illustrate the standard usage and operations of the Products. The peripheral conditions must

be taken into account when designing circuits for mass production.

Great care was taken in ensuring the accuracy of the information speciﬁed in this document.

However, should you incur any damage arising from any inaccuracy or misprint of such

information, ROHM shall bear no responsibility for such damage.

The technical information speciﬁed herein is intended only to show the typical functions of and

examples of application circuits for the Products. ROHM does not grant you, explicitly or

implicitly, any license to use or exercise intellectual property or other rights held by ROHM and

other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the

use of such technical information.

The Products speciﬁed in this document are intended to be used with general-use electronic

equipment or devices (such as audio visual equipment, ofﬁce-automation equipment, commu-

nication devices, electronic appliances and amusement devices).

The Products speciﬁed in this document are not designed to be radiation tolerant.

While ROHM always makes efforts to enhance the quality and reliability of its Products, a

Product may fail or malfunction for a variety of reasons.

Please be sure to implement in your equipment using the Products safety measures to guard

against the possibility of physical injury, ﬁre or any other damage caused in the event of the

failure of any Product, such as derating, redundancy, ﬁre control and fail-safe designs. ROHM

shall bear no responsibility whatsoever for your use of any Product outside of the prescribed

scope or not in accordance with the instruction manual.

The Products are not designed or manufactured to be used with any equipment, device or

system which requires an extremely high level of reliability the failure or malfunction of which

may result in a direct threat to human life or create a risk of human injury (such as a medical

instrument, transportation equipment, aerospace machinery, nuclear-reactor controller,

fuel-controller or other safety device). ROHM shall bear no responsibility in any way for use of

any of the Products for the above special purposes. If a Product is intended to be used for any

such special purpose, please contact a ROHM sales representative before purchasing.

If you intend to export or ship overseas any Product or technology speciﬁed herein that may

be controlled under the Foreign Exchange and the Foreign Trade Law, you will be required to

obtain a license or permit under the Law.

Thank you for your accessing to ROHM product informations.

More detail product informations and catalogs are available, please contact us.

ROHM Customer Support System

http://www.rohm.com/contact/

www.rohm.com

R0039

A


型号：	BD3508MUV
厂家：	ROHM
描述：	Ultra Low Dropout Linear Regulators for PC Chipsets 超低压差线性稳压器的PC芯片组稳压器 PC
文件：	总21页 (文件大小：679K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

BD3508MUV [ROHM]

相关型号：

BD3508MUV-E1

BD3508MUV-E2

BD3508MUV_09

BD3509MUV

BD3509MUV-TL

BD3509MUV_10

BD350S

BD350T

BD350YS

BD350YT

BD3512MUV

BD3512MUV-E2