ROHM BD95500MUV Technical data

High Performance Regulators for PCs

Switching Regulator with MOSFET for DDR-SDRAM Cores

BD95500MUV

●Description

BD95500MUV is a switching regulator with high output current (up to 6A) which can achieve low output voltage (0.7V to 5.0V) from a wide input voltage range (3V to 20V). High efficiency for the switching regulator can be realized by utilizing an internal N-MOSFET power transistor. A new technology called H realize ultra high transient response against load change. SLLM (Simple Light Load Mode) technology is also integrated to improve efficiency in light load mode, providing high efficiency over a wide load range. For protection and ease of use, the soft start function, variable frequency function, short circuit protection function with timer latch, over voltage protection function, and power good function are all built in. This switching regulator is specially designed for sets of various kinds.

●Features

1) Integrated low ON resistance N-MOSFET (TYP. 50mΩ)

2) H

3) Adjustable Simple Light Load Mode (SLLM), and forced continuous mode

4) Thermal Shut Down (TSD), Under Voltage LockOut (UVLO), Adjustable Over Current Protection (OCP), Over Voltage Protection (OVP), Short Circuit Protection(SCP) built-in

5) Soft start function to minimize rush current during startup

6) Adjustable switching frequency (f=200KHz～1000KHz)

7) Built-in output discharge function

8) VQFN040V6060 Package

9) Tracking Function

10) Integrated boot strap diode

11) Power Good function

●Applications

Mobile PC, Desktop PC, LCD-TV, Digital Components, etc

3

RegTM DC/DC converter controller

3

RegTM is a Rohm proprietary control method to

No.10030ECT21

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2010.05 - Rev.C

BD95500MUV

Technical Note

●Maximum Absolute Ratings (Ta=25℃)

Parameter Symbol Ratings Unit

Input Voltage 1 VCC 7 *1 V

Input Voltage 2 VDD 7 *1 V

Input Voltage 3 VIN 24 *1 V

BOOT Voltage BOOT 30 V

BOOT-SW Voltage BOOT-SW 7 V

LG Voltage LG VDD V

REF Voltage REF VCC V

Output Voltage VOUT/Is+/Is- VCC V

ILIM/SS/FS/MODE Voltage ILIM/SS/FS/MODE VCC V

VREG Voltage VREG VCC V

EN Input Voltage EN 7 V

Output Current (Average) Isw 6 A

Power Dissipation 1 Pd1 0.54 *2 W

Power Dissipation 2 Pd2 1.00 *3 W

Power Dissipation 3 Pd3 3.77 *4 W

Power Dissipation 4 Pd4 4.66 *5 W Operating Temperature Range Topr -10～+100 ℃ Storage Temperature Range Tstg -55～+150 ℃ Junction Temperature Tjmax +150 ℃

*1 Not to exceed Pd, ASO, and Tjmax=150℃. *2 Reduced by 4.3mW for each increase in Ta of 1℃ over 25℃ (when don’t mounted on a heat radiation board ) *3 Reduced by 8.0mW for increase in Ta of 1℃ over 25℃. (when mounted on a board 70.0mm×70mm×1.6mm Glass-epoxy PCB which has 1 layer. (Copper foil area : 0mm *4 Reduced by 30.1mW for increase in Ta of 1℃ over 25℃. (when mounted on a board 70.0mm×70mm×1.6mm Glass-epoxy PCB which has 4 layers.

st

(1

and 4th copper foil area : 20.2mm2, 2nd and 3rd copper foil area : 5505mm2))

*5 Reduced by 37.3mW for increase in Ta of 1℃ over 25℃. (when mounted on a board 70.0mm×70mm×1.6mm Glass-epoxy PCB which has 4 layers. (All copper foil area : 5505mm

2

))

2

))

●Operating Conditions (Ta=25℃)

Parameter

Symbol

MIN MAX

Ratings

Unit

Input Voltage 1 VCC 4.5 5.5 V

Input Voltage 2 VDD 4.5 5.5 V

Input Voltage 3 VIN 3.0 20 V

BOOT Voltage BOOT 4.5 25 V

SW Voltage SW -0.7 20 V

BOOT-SW Voltage BOOT-SW 4.5 5.5 V

MODE Input Voltage MODE 0 5.5 V

EN Input Voltage EN 0 5.5 V

Output Adjustable Voltage REF 0.7 2.0 V

Is Input Voltage Is+/Is- 0.7 2.7 V

MIN ON Time Tonmin - 200 nsec

*This product should not be used in a radioactive environment.

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BD95500MUV

●Electrical characteristics (Unless otherwise noted, Ta=25℃, VCC=5V, VDD=5V, EN / MODE=5V, VIN=12V, REF=1.8V, RFS=68kΩ）

Parameter Symbol

[Whole Device]

VCC Bias Current Icc - 1200 2000 μA VIN Bias Current Iin - 100 200 μA VCC Standby Current Iccstb - 0 10 μA EN＝0V VIN Standby Current Iinstb - 0 10 μA EN＝0V EN Low Voltage Enlow GND - 0.8 V EN High Voltage Enhigh 2.3 - 5.5 V EN Bias Current Ien - 7 10 μA

VREG Voltage Vreg 2.475 2.500 2.525 V

[Under Voltage Locked Out ]

VCC Threshold Voltage Vcc_UVLO 4.1 4.3 4.5 V VCC:Sweep up VCC Hysteresis Voltage dVcc_UVLO 100 160 220 mV VCC:Sweep down VIN Threshold Voltage Vin_UVLO 2.4 2.6 2.8 V VIN:Sweep up VIN Hysteresis dVin_UVLO 100 160 220 mV VIN:Sweep down VREG Threshold Voltage Vreg_UVLO 2.0 2.2 2.4 V VREG:Sweep up VREG Hysteresis Voltage dVreg_UVLO 100 160 220 mV VREG:Sweep down

[H3REGTM Control Block]

ON Time Ton 400 500 600 nsec MAX ON Time Tonmax - 3 6.0 μsec MIN OFF Time Toffmin - 450 550 nsec

[FET Block]

High Side ON Resistance HGhon - 50 80 mΩ Low Side ON Resistance HGlon - 50 80 mΩ

[SCP Block]

SCP Start up Voltage Vscp REF×0.60 REF×0.70 REF×0.80 V Delay Time Tscp - 1.0 2.0 ms

[OVP Block]

OVP Detect Voltage Vovp REF×1.16 REF×1.2 REF×1.24 V

[Soft Start Block]

Charge Current Iss 2 4 6 μA Discharge Current Idis 0.5 1.0 2.0 μA Standby Voltage Vss_stb - - 50 mV

[Over Current Protection Block]

Current Limit Threshold 1 Ilim1 40 50 60 mV

Current Limit Threshold2 Ilim2 160 200 240 mV ILIM=2.0V

[Vout Setting]

VOUT Offset Voltage 1 Voutoff1 REF-10m REF REF+10m V Ta=-10℃ to 100℃ VOUT Bias Current Ivout -100 0 100 nA REF Bias Current Iref -100 0 100 nA Is+ Input Current IIs+ -1 0 1 μA Is+=1.8V Is- Input Current IIs- -1 0 1 μA Is-=1.8V

[MODE Block]

SLLM Threshold VthSLLM VCC-0.5 - VCC V Forced Continuous Mode VthCONT GND - 0.5 V Input Impedance RMODE - 400 - kΩ

[Power Good Block]

VOUT Power Good Low Voltage VoutPL REF×0.85 REF×0.90 REF×0.95 V VOUT Power Good High Voltage VoutPH REF×1.05 REF×1.10 REF×1.15 V

Min. Typ. Max.

Limit

Unit Condition

Technical Note

Ireg=0 to 500uA, Ta =- 10 ℃ to 100℃*

ILIM=0.5V , Ta =- 10 ℃ to 100℃

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p

BD95500MUV

●Reference Data

2.500

2.498

2.496

2.494

VREG[V

2.492

2.490

-101030 50 7090 Ta(℃)

2.20

2.15

2.10

2.05

VREG[V

2.00

1.95

Sweep down

1.90

-101030507090 Ta(℃)

Fig.4 Ta vs UVLO (VREG)

3

2

1

0

-1

VOUT-REF [mV

-2

-3

-101030507090

Fig.7 Ta vs VOUT Offset

Ta

(℃)

100

80

SLLM

60

[%]

η

40

20

0

0.001 0.01 0.1 1 10

Fig.10 Io vs Efficiency

(V

Forced Continuous

Io(mA)

IN=7V, VOUT=1.5V)

Sweep up

4.30

4.25

4.20

4.15

VCC[V]

4.10

4.05

4.00

-101030507090

Sweep u

Sweep down

Ta(℃)

Fig.2 Ta vs UVLO (VCC)

2.20

2.15

2.10

2.05

VREG[V

2.00

1.95

1.90

-101030 50 7090

Sweep up

Sweep down

Ta(℃)

Fig.5 Ta vs EN Threshold

54

52

50

Is [mV

⊿

48

46

-101030507090

ILIM=0.5V

Ta (℃)

Fig.8 Ta vs Current Limit

Threshold

100

80

60

[%]

η

40

20

0

0.001 0.01 0.1 1 10

SLLM

Forced Continuous

Io(mA)

Fig.11 Io vs Efficiency

(VIN=12V, VOUT=1.5V)

Technical Note

2.70

2.65

2.60

2.55

VIN[V]

2.50

2.45

2.40

-101030507090

Fig.3 Ta vs UVLO (VIN) Fig.1 Ta vs VREG

2.8

2.4

2.0

1.6

1.2

VREG(V)

0.8

0.4

0.0

01.534.56

Fig.6 Vcc vs VREG

400

360

320

280

frequency[kHz]

240

200

0 5 10 15 20 25

Fig.9 VIN vs f

100

80

60

[%]

η

40

20

0

0.001 0.01 0.1 1 10

SLLM

Fig.12 Io vs Efficiency

(V

IN=19V, VOUT=1.5V)

Ta(℃)

Vcc(V)

Io=0A

VIN( V)

Io(mA)

Sweep u

Sweep down

Middle: 25℃

Right: -10℃

Io=2A

Forced Continuous

Left: 100℃

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2010.05 - Rev.C

BD95500MUV

●Reference Data

VOUT

HG/LG

IOUT

Fig.13 Transient Response

IN=7V)

(V

VOUT

HG/LG

IOUT

Fig.16 Transient Response

(VIN=7V)

VOUT

IL

HG/LG

Fig.19 SLLM Mode

OUT=0A)

(I

IL

HG/LG/SW

Fig.22 Continuous Mode

(Io=0A)

IL

HG/LG/SW

VOUT

HG/LG

IOUT

Fig.14 Transient Response

(VIN=12V)

VOUT

HG/LG

IOUT

Fig.17 Transient Response

(VIN=12V)

VOUT

IL

HG/LG

Fig.20 SLLM Mode

OUT=0.4A)

(I

Fig.23 Continuous Mode

(Io=4A)

IL

HG/LG/SW

Technical Note

VOUT

HG/LG

IOUT

Fig.15 Transient Response

(VIN=19V)

VOUT

HG/LG

IOUT

Fig.18 Transient Response

(V

IN=19V)

VOUT

IL

HG/LG

Fig.21 SLLM Mode

OUT=1A)

(I

Fig.24 OCP Status

(Io=5A)

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V

BD95500MUV

●Reference Data

VIN

HG/LG

VOUT

Fig.25 V

IN change

(5→19V)

1.52

1.51

1.50

Output Voltage [

1.49

Continuous

SLLM

1.48

0.001 0.01 0. 1 1 10

Iout [A]

Fig.28 IOUT vs VOUT

●Block Diagram

EN

VDD

Vcc

5

Reference

39

Block

Vcc

PGOOD

V

REF

REF×0.85

SS×0.85

V

OUT

10

1

OUT

11

Thermal

Protection

Power

Good

EN/UVLO

TSD

6

VIN

ILIM

SCP

TSD

UVLO

VIN

SCP

8

VREG

Delay

SS

UVLO

GND F S

VIN

HG/LG

VOUT

37

H3RegTM

Controller

Block

Fig.26 V

IN change

(19→5V)

500

400

Continuous

300

Continuous

200

Frequency [kHz

100

0

0.001 0.01 0.1 1 10

SLLM

Iout [A]

Fig.29 IOUT vs f

SSVREGVINS

ILIM

×

Current

Limit

0.1

9

OVP

SLLM/

MODE

13

2.5VReg

40

MODE N.C.

7

2.5V

REF×1.2

OUT

V

R Q

S

42

SLLM

Soft Start

Is+

Technical Note

EN

SS

OUT

V

PGOOD

Fig.27 EN wake up

60

50

40

]

℃

30

Tc [

Δ

20

10

0

0123456

Io [A]

Fig.30 IOUT vs ΔTc

VDD

BOOT

SS

Driver

Circuit

12

Is-

38

31

VIN

|

36

22

SW

|

29

14

VDD

15

PGND

|

21

30

PGND

3

CE

C IN

3.3V

～

20V

V OUT

C

OUT

5V

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BD95500MUV

Technical Note

●Pin Configuration

VIN

31

29 28 27 26 25 30

24 23 22

VIN

32

33

34

35

36

VINS

BOOT

EN

MODE

37

38

39

40

1 2 3 4 5

PGOOD

N.C.

ILIM CE

6

VC C GN D

7 8 9

VREG FS

*Connect the bottom side (FIN) to the ground terminal

●Pin Function Table

PIN No. PIN name PIN function

1 PGOOD

Power Good Output Pin(+/-10% Window)

2 N.C.

3 CE

4 ILIM

5 VCC

6 GND

7 VREG

8 FS

9 SS/TRACK

10 REF

11 VO U T

12 Is-

13 Is+

14 VDD

15-21 PGND

22-29 SW

30 PGND

31-36 VIN

37 VINS

38 BOOT

39 EN

Ceramic Capacitor Reactive Pin

Current Limit Setting Pin

Power Supply Input pin (Control Block)

Sense GND

IC Reference Voltage (2.5V/500uA) Switching Frequency Adjustable Pin (30k～100kΩ)

Soft Start Setting Pin (w/ Capacitor)/Tracking Voltage Input Pin

Vo Setting Pin

Output Voltage Sense Pin

Current Sense Pin -

Current Sense Pin +

FET Driver Power Supply Pin (5V Input)

Power GND Pin

High Side FET Source Pin

Power GND Pin

Battery Voltage Input pin (3.3~20V Input)

Battery Voltage Sense pin

HG Driver Power Supply Pin

Enable Input pin (IC ON when High)

Control Mode Adjustment Pin

40 MODE

Low: Continuous High: SLLM

bottom FIN

Substrate connection

SS/

TRACK

PGND SW SW SW SW SW SW SW SW PGND

REF

-

21

10

20

19

18

17

16

15

14

13

12

11

PGND

VDD

Is+

Is-

VOUT

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BD95500MUV

●Pin Descriptions ・VCC (5 Pin)

This is the power supply pin for IC internal circuits, except the FET driver. The input supply voltage range is 4.5V to 5.5V. It is recommended that a 10Ω/0.1uF C-R filter be put in this pin from VDD rail.

・EN (39 Pin)

When EN pin voltage is at least 2.3V, the status of this switching regulator becomes active. Conversely, the status switches off when EN pin voltage goes lower than 0.8V and circuit current becomes 0µA.

・VDD (14 Pin)

This is the power supply pin to drive the LOW side FET and for Boot-strap diode. It is recommended that a 1~10µF bypass capacitor be established to compensate for rush current during the FET ON/OFF transition.

・VREG (7 Pin)

This is the reference voltage output pin. The voltage is 2.5V, with 500uA current ability. It is recommended that a

0.22~1µF capacitor (X5R or X7R) be established between VREG and GND (6 Pin). When REF is not adjusted from the external voltage supply, the REF voltage can be adjusted using the external resistor divider of VREG.

・REF (10 Pin)

This is the output voltage adjustment pin by resistor divider network from VREG pin (0.7~2.0V). It is also very convenient for synchronizing external voltage supply. The IC controls the output voltage (REF≒VOUT).

・ILIM (4 Pin)

BD95500MUV detects the voltage between Is+ pin and Is- pin and limits the output current (OCP). Voltage equivalent to 1/10 of the ILIM voltage is the voltage drop of external current sense resistor. A very low current sense resistor or inductor DCR can also be used for this platform.

・SS/TRACK (9 Pin)

This is the adjustment pin to set the soft start time. SS voltage is low during standby status. When EN is ON, the soft start time can be determined by the SS charge current and capacitor between SS-GND. Until SS reaches REF voltage, the output voltage is equivalent to SS voltage. And also this pin enables to operate tracking function. The output voltage keeps track of a power supply rail by connecting 10kΩ resistance between the power supply rail and SS/TRACK pin.

・VINS (37 Pin)

The duty cycle is determined by input voltage and controls output voltage. In other words, the output voltage is affected by input voltage. Therefore, when VINS voltage fluctuates, the output voltage becomes also unstable. Since the VINS line is also the input voltage of the switching regulator, stability depends on the impedance of the voltage supply. It is recommended to establish a bypass capacitor or CR filter suitable for the actual application.

・FS (8 Pin)

This is the pin to adjust the switching frequency with the resistor. It is recommended that a resistor be established to GND (6 pin).The frequency range is from 200kHz to 1000kHz.

・Is+ (13 pin), Is- (12 pin)

These pins are connected to both sides of the current sense resistor to detect output current. The voltage drop between Is+ and Is- is compared with the voltage equivalent to 1/10 of ILIM voltage. When this voltage drop hits the specified voltage level, the output voltage is OFF. Since the maximum input voltage is 2.7V, set the output voltage by the resistance division value in case the output voltage is 2.7V or more.

・BOOT (38 pin)

This is the voltage supply to drive the high side FET and a Diode for BOOT strap function is built in. The maximum absolute ratings are 30V (from GND) and 7V (from SW). BOOT voltage swings between (VIN+Vcc) and Vcc during active operation.

・PGOOD (1 pin)

This pin is output pin for Power Good. It is open drain pin and recommended to connect to other power supply through the pull-up resistance (about 100kΩ).

・CE (3 pin)

This pin is for the ceramic capacitor. It is useful to utilize low ESR capacitor for output capacitor.

・MODE (40 pin)

This is the control mode changeable pin. The status is Low : continuous mode, the status is High : SLLM

・VOUT (11 pin)

This is the monitor pin for output voltage. This IC controls the voltage in the status of REF≒VOUT. When output voltage is required 2V or more, set the output voltage by the resistance division value.

・SW (22-29 pin)

This is connected pin for coil. SW voltage swings between VIN and GND. It is recommended to connect by heavy and short pattern to coil.

・VIN (31-36 pin)

This is input power supply pin. Recommend input voltage is 3.3V to 20V. Connect the input capacitor against PGND directly.

・PGND (15-21, 30 pin)

This is power ground pin. It is recommended to connect by heavy and short pattern. Connect in reverse side of IC when connecting to GND (6 pin).

Technical Note

TM

.

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BD95500MUV

Technical Note

●Explanation of Operation

The BD95500MUV is a switching regulator controller incorporating ROHM’s proprietary H system. When V

OUT drops due to a rapid load change, the system quickly restores VOUT by extending the tON time interval.

3

RegTM CONTROLLA control

Thus, it serves to improve the regulator’s transient response. Activating the Light Load Mode will also exercise Simple Light Load Mode (SLLM) control when the load is light, to further increase efficiency.

H3RegTM control (Normal operation)

VOUT

REF

When V

OUT falls to a threshold voltage (REF), the drop is

detected, activating the H

3

RegTM CONTROLLA system.

HG

TON=

REF

VIN

×

1

f

[sec]・・・(1)

LG

HG output is determined by the formula above.

OUT drops due to a rapid load change)

(V

VOUT

REF

Io

tON+α

When VOUT drops due to a rapid load change, and the voltage remains below V

REF after the programmed tON

time interval has elapsed, the system quickly restores

OUT by extending the tON time, improving the transient

V response.

HG

LG

VIN

REF

H3RegTM

CONTROLLA

VOUT

Q

R

SLLM

S

Driver

Circuit

SLLM

HG

LG

VIN

VOUT

SW

PGND

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T

y

BD95500MUV

●Timing Chart ・Soft Start Function

EN

TSS

SS

OU

V

IIN

・Soft Stop Function

EN

1.2V

SS

TSS(OFF)

OU

V

Tdela

・Timer Latch Type Short Circuit Protection

VOUT

REF×0.70

1ms

SCP

EN/UVLO

0.1V

Spontaneous Discharge (It is determined by load and output capacitor)

Technical Note

Soft start is exercised with the EN pin set high. Current control takes effect at startup, enabling a moderate output voltage “ramping start.” Soft start timing and incoming current are calculated with formulas (2) and (3) below.

Soft start time

REF×Css

Tss=

4μA(typ)

Rush current

I

IN (ON)=

Co×VOUT

(Css: Soft start capacitor; Co: Output capacitor)

Soft stop is exercised with the EN pin set low. Current control takes effect at startup, enabling a moderate output voltage. Soft start timing and incoming current are calculated with formulas (4) below.

Soft stop time

T

SS (OFF) =

ΔV

SS= 1.2[V] (typ)

=

Tdelay

1μA(typ)

When output voltage (Is-) falls to REF×0.7 or less, SCP comparator inside IC is exercised. If the status of High is continued 1ms or more (programmed time inside IC), the IC goes OFF. It can be restored either by reconnecting the EN pin or disabling UVLO.

Ts s

(REF+2V

1μA (typ )

CSS

[sec]

BE)×Css

[sec]

・・・(2)

[A]

・・・(3)

・・・(5)

[sec]

・・・(4)

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BD95500MUV

・Output Over Voltage Protection

VOUT

REF×1.2

HG

LG

Switching

・Over current protection circuit

HG

tON

tMAX

LG

ILIMIT

IL

・Synchronous operation with external power supply

3.3V (External Power Supply)

1.5 V (BD95500 Output 1)

tON

Technical Note

When output rise to or above REF×1.2, output ove voltage protection is exercised, and low side FET goes up maximum for reducing output. （LG=High, HG=Low）. When output falls, it returns to the standard mode.

During the normal operation, when VOUT becomes less than REF Voltage, HG becomes High during the time t (P9). However, when inductor current exceeds I threshold, HG becomes OFF.

fter MAX ON TIME, HG becomes ON again if the output voltage is lower than the specific voltage level and I lower than I

LIMIT

level.

These power supply sequences are realized to connect SS pin to other power supply output through the resistance (10kΩ).

ON

LIMIT

is

L

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[A]

[H]

(

)

[A]

A

BD95500MUV

Technical Note

●External Component Selection

1. Inductor (L) selection

ΔIL

VIN

HG

LG

PGND

Output Ripple Current

SW

IL

VOUT

L

Co

The inductor value is a major influence on the output ripple current.

s formula (5) below indicates, the greater the inductor or the

switching frequency, the lower the ripple current.

ΔI

L=

IN-VOUT)×VOUT

L×VIN×f

・・・(4)

(V

The proper output ripple current setting is about 30% of maximum output current.

L=0.3×IOUTmax. [A]・・・(5)

ΔI

(VIN-VOUT)×VOUT

L=

L: output ripple current; f: switch frequency)

(ΔI

L×VIN×f

・・・(6)

※Passing a current larger than the inductor’s rated current will cause magnetic saturation in the inductor and decrease

system efficiency. In selecting the inductor, be sure to allow enough margin to assure that peak current does not exceed the inductor rated current value.

※To minimize possible inductor damage and maximize efficiency, choose a inductor with a low (DCR, ACR) resistance.

L

) Selection

O

ESR

ESL

Co

VOUT

When determining the proper output capacitor, be sure to factor in the equivalent series resistance and equivalent series inductance required to set the output ripple voltage 20mV or more. In selecting the limit of inductor, be sure to allow enough margin for output voltage. Output ripple voltage is determined as in formula (7) below.

ΔVOUT=ΔIL×ESR + ESL×ΔIL / TON・・・(7)

L: Output ripple current; ESR: CO equivalent series resistance,

(ΔI ESL: equivalent series inductance)

2. Output Capacitor (C

VIN

HG

SW

LG

PGND

Output Capacitor

Please give due consideration to the conditions in formula (8) below for output capacity, bear in mind that output rise time must be established within the soft start time frame.

Co≦

TSS×(Limit-I

V

OUT

OUT)

・・・(8)

Tss: Soft start time (See formula (2) in P10) Limit: Over current detection (See formula (10)(11) in P13)

Note: Improper capacitor may cause startup malfunctions

3. Input Capacitor (Cin) Selection

HG

LG

VIN

SW

Cin

VOUT

L

Co

PGND

Input Capacitor

The input capacitor selected must have low enough ESR resistance to fully support large ripple output, in order to prevent extreme over current. The formula for ripple current IRMS is given in (9) below.

√

V

IN

IRMS=IOUT×

Where V

IN=2×VOUT, IRMS=

VIN-VOUT

VIN

I

OUT

・・・(9)

2

A low ESR capacitor is recommended to reduce ESR loss and maximize efficiency.

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BD95500MUV

4. Setting Detection Resistance

VIN

HG

SW

L

LG

IL

PGND

Is+

Is-

Current limit

VIN

HG

SW

IL

L

LG

r

PGND

Is+

Is-

Current limit

detect point IL

ILIMIT

0

VIN

HG

SW

LG

PGND

L

IL

Is+

Is-

VOUT

Current limit

R

RL

C

R1 R1

R2 R2

Technical Note

The over current protection function detects the output ripple current peak value. This parameter (setting value) is determined as in formula (10) below.

ILIM×0.1

VOUT

Co

ILMIT=

(V

When the over current protection is detected by DCR of coil L, this parameter (setting value) is determined as in formula (11) below.

VOUT

Co

ILMIT=VILIM×0.1×

(RL=

(V

current becomes specific threshold, the gate voltage of the high side MOSFET becomes low. Since the peak voltage of the inductor ripple current is detected, this operation can sense high current ripple operation caused by inductance saturated rated current and lead to high reliable systems.

t

When the output voltage is 2.7V or more, use the resistance for setting output voltage like left figure, for Is+ and Is-.

R

Co

VOUT

to the divided ratio.

I

(VILIM: ILIM voltage R: Detection resistance)

V

[A]・・・(10)

R

ILIM: ILIM voltage, R: Detection resistance)

r×C

[A]・・・(11)

L

)

r×C

ILIM:ILIM voltage, RL: the DCR value of coil)

s soon as the voltage drop between Is+ and Is- generated by the inductor

ccording to the setting value above, ILIMIT setting current is in proportion

LMIT=

R1+R2

R1

VLIMIT×0.1

×

R

[A]・・・(12)

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2010.05 - Rev.C

y

t

]

V

t

BD95500MUV

5.Setting frequency

3000

2500

2000

1500

TON [nsec

1000

500

0

050100150200

VIN=5V

7V 12V 16V 19V

1200

1000

800

600

Frequency [kHz

400

200

0

0 50 100 150 200

Res istance [kΩ]

6. Setting standard voltage (REF)

REF

Outside voltage

VOUT

VREG

R1

REF

R2

VOUT

REF=1.8

RFS [kΩ]

VIN=5V

VIN

H3RegTM

CONTROLLA

VIN

H3RegTM

CONTROLLA

7V 12V 16V 19V

RQ

S

RQ

S

Technical Note

The On Time (t resistance value connected to FS pin. But actually SW rising time and falling time come up due to influence of the external MOSFET gate capacit or switching speed and tON is increased. The frequency is determined by the following formula after tON, input current and the REF voltage are fixed.

F=

・・・(13)

V

Consequently, total frequency becomes lower than the formula above.

ON is also influenced by Dead Time around the outpu

T current 0A area in continuous mode. This frequency becomes lower than setting frequency. It is recommended to check the steady frequency in large current area (at the point where the coil current doesn’t back up).

It is available to synchronize setting the reference voltage (REF) with outside supply voltage [V] by using outside power supply voltage.

It is available to set the reference voltage (REF) by the resistance division value from VREG in case it is no set REF from an external power supply.

REF= ×VREG [V]・・・(14)

R1+R2

ON) at steady state is determined by

REF

IN×tON

R2

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2010.05 - Rev.C

BD95500MUV

7. Setting output voltage

This IC is operated that output voltage is REF≒V

OUT.

And it is operated that output voltage is feed back to FB pin in case the output voltage is 0.7V to 2.0V.

VIN

REF

H3RegTM

CONTROLLA

VOUT

RQ

S

SLLM

Driver

Circuit

In case the output voltage range is 0.7V to 2.0V.

It is operated that the resistance division value of the output voltage is feed back to V

OUT pin in case the output voltage is

more than 2.0V.

R1+R2

output voltage≒ ×REF [V]・・・(15)

R2

And then the frequency is also in proportion to the divided ratio.

F=

R2

R1+R2

×

REF

VIN×tON

VIN

・・・(16)

REF

H3RegTM

CONTROLLA

VOUT

RQ

S

SLLM

Driver Circuit

In case the output voltage is more than 2.0V.

Technical Note

VIN

Output voltage

VIN

Output voltage

R1

R2

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2010.05 - Rev.C

BD95500MUV

Technical Note

●I/O Equivalent Circuit

1pin (PGOOD) 3pin (CE) 4pin (ILIM)

VCC

7pin (VREG) 8pin (FS) 9pin (SS/TRACK)

VCC

10pin (REF) 11pin (VOUT) 12pin (Is-)

VCC

13pin (Is+) 22-29pin (SW) 31-36pin (VIN)

VCC

VIN

PGND

SW

37pin (VINS) 38pin (BOOT) 39pin (EN)

VDD

40pin (MODE)

VCC

SW

VCC

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2010.05 - Rev.C

BD95500MUV

Technical Note

●Evaluation Board Circuit (Frequency=300kHz Continuous/SLLM Circuit Example)

VIN (5V)

GND_VIN

VDD

1 3

6

SW2

EN

MODE

5

C15

C12

C13

C11

C16

R15

29

30

31

VIN

32

VIN

33

VIN

34

VIN

35

VIN

36

VIN

37

VIN_S

38

BOOT

39

EN

40

MOD

E

PGND

1

PGOOD

SW

NC

2

SW

27

28

SW

26

SW

BD95500MUV

VQFN040V6060

ILIM

CE

3

4

ILIM

VCC

5

R2

C1

R3

C2

R4

L1

D1

R14

25

SW

GND

6

23

24

SW

FS

VREG

7

8

C3

R5

R8

R9

SW

9

VREG

R6

21

22

PGND

VDD

Is+

Is-

VOUT

REF

SS

10

R18

C4

20

19

18

17

16

15

14

13

12

11

SS

C5

R7

REF

+

C10

R20

R19

R10

C9

C8

C14

C6

C14

R20

R19

R13

Q1

VDD(5 V)

VOUT (3.3V/6A)

GND_VOUT

R11

GND_VDD

●Evaluation Board Parts List

Part No

Value Company Part name Part No Value Company Part name

U1 - ROHM BD95500MUV R17 100kΩ ROHM MCR03 Series

R12

IPULSE

C7

D1 - ROHM RB051L-40 R18 1kΩ ROHM MCR03 Series

L1 4.3uH Sumida CDEP105NP-4R3MC-88 R19 10kΩ ROHM MCR03 Series

Q1 - - - R20 12kΩ ROHM MCR03 Series

R1 0Ω ROHM MCR03 Series C1 0.1uF MURATA GRM18 Series

R2 0Ω ROHM MCR03 Series C2 100pF MURATA GRM18 Series

R3 100kΩ ROHM MCR03 Series C3 0.47uF MURATA GRM18 Series

R4 150kΩ ROHM MCR03 Series C4 1000pF MURATA GRM18 Series

R5 68kΩ ROHM MCR03 Series C5 1000pF MURATA GRM18 Series

R6 100kΩ ROHM MCR03 Series C6 10uF MURATA GRM21 Series

R7 150kΩ ROHM MCR03 Series C7 - MURATA GRM18 Series

R8 - ROHM MCR03 Series C8 220uF

SANYO or something

functional high

polymer

R9 100kΩ ROHM MCR03 Series C9 10uF MURATA GRM21 Series

R10 10Ω ROHM MCR03 Series C10 0.1uF MURATA GRM18 Series

R11 - ROHM MCR03 Series C11 10uF

KYOSERA or

something

CM316B106M25A

R12 10Ω ROHM MCR03 Series C12 0.1uF MURATA GRM18 Series

R13 ROHM MCR03 Series C13 0.1uF MURATA GRM18 Series

R14 1kΩ ROHM MCR03 Series C14 100pF MURATA GRM18 Series

R15 1kΩ ROHM MCR03 Series C15 10uF

KYOSERA or

something

CM316B106M25A

R16 100kΩ ROHM MCR03 Series C16 0.1uF MURATA GRM18 Series

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17/20

2010.05 - Rev.C

BD95500MUV

●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) Power supply lines

Design PCB layout pattern to provide low impedance GND and supply lines. To obtain a low noise ground and supply line, separate the ground section and supply lines of the digital and analog blocks. Furthermore, for all power supply terminals to ICs, connect a capacitor between the power supply and the GND terminal. When applying electrolytic capacitors in the circuit, not that capacitance characteristic values are reduced at low temperatures.

(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 Temp. [℃] (typ.) Hysteresis Temp. [℃] (typ.)

BD95500MUV 175 15

Technical Note

(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.

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2010.05 - Rev.C

①

P

iti

P

iti

BD95500MUV

(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.

Pin A

N

+

P

Parasitic element

GND

(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.

●Power Dissipation

VQFN040V6060

5.0

④4.66W

4.5

4.0

③3.77W

3.5

3.0

2.5

2.0

1.5

Power Dissipation: Pd [W]

1.0

0.5

②1.00W

①0.54W

0

25 50 75 100 125 150

IC unit time

θj-a=231.5℃/W ②1 layer (Substrate surface copper foil area : 0mm θj-a=125.0℃/W ③4 layer (Substrate surface and bottom copper foil area : 20.2mm2 2nd and 3rd copper foil area : 5505mm2) θj-a=33.2℃/W ④4 layer (all layers copper foil area : 5505mm2) θj-a=26.8℃/W

+

P

P substrate

Resistor Transistor (NPN)

Pin B

Pin A

N

N N

aras

element

c

P+

Parasitic element

B

C

E

N

GND

P

P+

P substrate

N

GND

Example of IC structure

Ambient Temperature :Ta [℃]

2

)

Technical Note

Pin B

C

B

E

aras

element

Other adjacent elements

GND

c

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19/20

2010.05 - Rev.C

BD95500MUV

●Ordering part number

B D 9 5 5 0 0 M U V - E 2

Part No. Part No.

VQFN040V6060

1.0MAX

0.08 C0.2

0.4±0.1

0.75

6.0±0.1

1PIN MARK

S

3.7±0.1

110

40

31

0.5

2130

0.25

11

20

+0.03

+0.05

-

0.04

0.02

-

S

(0.22)

3.7±0.1

(Unit : mm)

Package MUV : VQFN040V6060

Embossed carrier tapeTape

Quantity

Direction of feed

2000pcs E2

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

Reel

1pin

Packaging and forming specification E2: Embossed tape and reel

Direction of feed

Order quantity needs to be multiple of the minimum quantity.

∗

Technical Note

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2010.05 - Rev.C

Notes

No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd.

The content specied herein is subject to change for improvement without notice.

The content specied 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 specications, 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 specied 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 specied 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.

Notice

The Products specied in this document are intended to be used with general-use electronic equipment or devices (such as audio visual equipment, ofce-automation equipment, communication devices, electronic appliances and amusement devices).

The Products specied in this document are not designed to be radiation tolerant.

While ROHM always makes effor ts 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 injur y, re or any other damage caused in the event of the failure of any Product, such as derating, redundancy, re 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, fuelcontroller 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 specied 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/

R1010

A

ROHM BD95500MUV Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual