ROHM BD6586MUV Technical data

LED Drivers for LCD Backlights

White Backlight LED Driver for Medium to Large LCD Panels (Switching Regulator Type)

BD6586MUV

●Description

BD6586MUV is white LED driver IC with PWM step-up DC/DC converter that can boost max 24V and current driver that can drive max 25mA. The wide and precision brightness can be controlled by external PWM pulse. BD6586MUV has very accurate current drivers, and it has few current errors between each strings.So, it will be helpful to reduce brightness spots on the LCD.Small package type is suited for saving space.

●Features

1) High efficiency PWM step-up DC/DC converter (fsw=1MHz)

2) High accuracy & good matching (±3.0%) current drivers 4ch (MAX.25mA/ch)

3) 28V power Nch MOSFET

4) Soft Start

5) Drive up to 6

6) Rich safety functions  Over-voltage protection  Output Short protection  External SBD open detect  Over current limit  Thermal shutdown  UVLO

7) Small & thin package (VQFN024V4040) 4.0 × 4.0 × 1.0mm

●Applications

All middle size LCD equipments backlight of Notebook PC, portable DVD player, car navigation systems, etc.

●Absolute maximum ratings (Ta=25 ℃)

in series, 4 strings in parallel

No.11040ECT35

Parameter Symbol Ratings Unit Condition

Maximum applied voltage 1 VMAX1 7 V

Maximum applied voltage 2 VMAX2 25 V LED1, LED2, LED3, LED4,

Maximum applied voltage 3 VMAX3 30.5 V SW

Maximum applied voltage 4 VMAX4 50.5 V VDET

Power dissipation 1 Pd1 500 *1 mW

Power dissipation 2 Pd2 780 *2 mW

Power dissipation 3 Pd3 1510 *3 mW

Operating temperature range Topr -40 ~ +85 ℃

Storage temperature range Tstg -55 ~ +150 ℃

*1 Reduced 4.0mW/ ℃ With Ta>25 ℃ when not mounted on a heat radiation Board. *2 1 layer (ROHM Standard board) has been mounted. Copper foil area 0mm *3 4 layer (JEDEC Compliant board) has been mounted. Copper foil area 1layer 6.28mm

, Copper foil area 2~4layers 5655.04mm2, When it’s used by more than Ta=25 ℃, it’s reduced by 12.1mW/ ℃.

, When it’s used by more than Ta=25 ℃, it’s reduced by 6.2mW/ ℃.

VBAT, EN1, EN2, TRSW, PWM,TESTO, ISET, TEST

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1/19

2011.6 - Rev.C

BD6586MUV

●Recommended operating range (Ta=-40 ℃ ~ +85 ℃)

Parameter Symbol

Power supply voltage VBAT 2.7 3.6 5.5 V

●Electrical characteristic (Unless otherwise specified, VBAT=3.6V, Ta = +25 ℃)

Parameter Symbol

[EN1, EN2, PWM Terminal]

EN threshold voltage (Low) VthL 0 - 0.4 V

EN threshold voltage (High) VthH 1.4 - 5.5 V

EN terminal input current Iin - 8.3 16.0 µA Input=2.5V

[Under Voltage Lock Out]

Under Voltage Lock Out UVLO 2.05 2.35 2.65 V VBAT falling edge

[Switching Regulator]

Ratings

Min. Typ. Max.

Limits

Min. Typ. Max.

Unit Condition

Technical Note

Quiescent Current

Current Consumption

LED Control voltage

Over Current Limit

SBD Open Protect

Switching frequency

Duty cycle limit

Over voltage limit

SW Transistor On Resistance

[Current driver]

LED maximum current

LED current accuracy

LED current matching

ISET voltage

LED current limiter

LED Terminal Over Voltage Protect

*1 This parameter is tested with DC measurement.

Iq - 0.1 2.0 µA

Idd - 2.2 4.6 mA

VLED 0.4 0.5 0.6 V

Ocp 1.1 1.5 2.5 A

Sop - - 0.1 V

fSW 0.7 1.0 1.3 MHz

Duty 91 95 99 %

Ovl 25.0 25.5 26.0 V

RSW - 0.24 0.32 

ILMAX - - 25 mA

ILACCU - - ±5 %

ILMAT - - ±3 %

Iset 0.5 0.6 0.7 V

ILOCP 35 60 90 mA

LEDOVP 10.0 11.5 13.0 V

EN1=EN2=PWM=0V

VDET=0V,ISET=24k

Detect voltage of VDET pin

LED1-4=0.3V

Isw=100mA

ILED=20mA

Each LED current/Average (LED1- 4) ILED=20mA

Current limit value at ISET resistance 4.7k setting LED1, 2, 3, 4=0.5V

EN1=EN2=PWM=2.5V

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2/19

2011.6 - Rev.C

BD6586MUV

●Block diagram, I/O equivalent circuit diagram

VBAT

UVLO

VBAT

TRSW

PGND

N.C.

GND

TSD

Current SENCE

EN1

Reference

TEST

EN2

TESTO

Soft start

Pulse

Control

OSC

N.C.

PWM COMP

SBD OPEN/ Output short PROTECT

Output Over Voltage PROTECT

ERRAMP

ISET

Resistor driver

ISET

PWM

GND

LED TERMINAL OPEN/SHORT DETECTOR

Current Drive

Fig.1 Block diagram Fig.2 I/O equivalent circuit diagram

●Pin assignment table

PIN Name In/Out PIN number Function

1 VBAT In Battery input G

2 EN1 In Power control pin A

3 EN2 In Power control pin A

4 GND - GND for DC/DC B

5 PWM In PWM input pin for power ON/OFF only driver A

6 ISET In Register connection for LED current setting D

7 GND - GND for ISET Register B

8 LED1 In Current sink for LED1 C

9 LED2 In Current sink for LED2 C

10 GND - GND for Current Driver B

11 LED3 In Current sink for LED3 C

12 LED4 In Current sink for LED4 C

13 TEST In TEST input (Pull down 100k to GND) A

14 TESTO Out TEST output D

15 N.C. - No connect pin E

16 SW Out Switching Tr drive Pin F

17 SW Out Switching Tr drive Pin F

18 SW Out Switching Tr drive Pin F

19 VDET In Detect input for SBD open and OVP C

20 N.C. - No connect pin E

21 PGND - PGND for switching transistor D

22 PGND - PGND for switching transistor D

23 N.C. - No connect pin E

24 TRSW Out The gate of Switching Tr D

RETURN

SELECT

LED

Technical Note

VDET

4ch

GND

LED1

LED2

LED3

LED4

VBAT

GND

VBAT

GND

PGND

VBAT

PGND

Terminal equivalent

circuit diagram

GND

PGND

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3/19

2011.6 - Rev.C

BD6586MUV

●Description of Functions

1) PWM current mode DC/DC converter While BD6586MUV is power ON, the lowest voltage of LED1, 2, 3, 4 is detected, PWM duty is decided to be 0.5V and output voltage is kept invariably. As for the inputs of the PWM comparator as the feature of the PWM current mode, one is overlapped with error components from the error amplifier, and the other is overlapped with a current sense signal that controls the inductor current into Slope waveform to prevent sub harmonic oscillation. This output controls internal Nch Tr via the RS latch. In the period where internal Nch Tr gate is ON, energy is accumulated in the external inductor, and in the period where internal Nch Tr gate is OFF, energy is transferred to the output capacitor via external SBD. BD6586MUV has many safety functions, and their detection signals stop switching operation at once.

2) Soft start BD6586MUV has soft start function. The soft start function prevents large coil current. Rush current at turning on is prevented by the soft start function. After EN1, EN2 are changed L H, soft start becomes effective for within 1ms and soft start doesn't become effective even if EN1, EN2 are changed L H after that. And, when the H section of PWM is within 1ms, soft start becomes invalid when PWM is input to H more than three times. The invalid of the soft start can be canceled by making EN1, EN2, PWM  L. And, a soft start function doesn't work after a protection function release.

3) External SBD open detect and over voltage protection BD6586MUV has over boost protection by external SBD open and over voltage protection. It detects VDET voltage and is stopped output Tr in abnormal condition. Details are as shown below.  External SBD open detect

In the case of external SBD is not connected to IC, the coil or internal Tr may be destructed. Therefore, at such an error as VOUT becoming 0.1V or below, the Under Detector shown in the figure works, and turns off the output Tr, and prevents the coil and the IC from being destructed. And the IC changes from activation into non-activation, and current does not flow to the coil (0mA).

 Over voltage protection

At such an error of output open as the output DC/DC and the LED is not connected to IC, the DC/DC will boost too much and the VDET terminal exceed the absolute maximum ratings, and may destruct the IC. Therefore, when VDET becomes sensing voltage or higher, the over voltage limit works, and turns off the output Tr, and the pressure up made stop. At this moment, the IC changes from activation into non-activation, and the output voltage goes down slowly. And, when the output voltage becomes the hysteresis of the over voltage limit or below, the output voltage pressure up to sensing voltage once again and unless the application error is recovered, this operation is repeated.

4) Thermal shut down BD6586MUV has thermal shut down function. The thermal shut down works at 175C or higher, and while holding the setting of EN1, EN2 control from the outside, turns into non operation condition from operation condition. And at 175C or below, the IC gets back to its normal operation.

5) Over Current Limit Over current flows the current detection resistor between switching transistor source and PGND, then the voltage of that resistor turns more than detection voltage. Over current protection is operating and it is prevented from flowing more than detection current by reducing ON duty of switching Tr without stopping boost. As over current detector of BD6586MUV is detected peak current, current more than over current setting value does not flow.

6) Under Voltage Lock Out(UVLO) When VBAT declines in 2.35V (Typ.) from the condition of the power-on, DC/DC and a current driver are changed from a state of movement to the condition at the time of the non-movement. And, it is returned in a state of movement when VBAT is raised beyond 2.55V (Typ.).

Technical Note

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4/19

2011.6 - Rev.C

BD6586MUV

●Operating of the application deficiency

1) When 1 LED or 1parallel OPEN during the operating the LED parallel which became OPEN isn't lighting, but other LED parallel is lighting. Then, Output boosts up to the over voltage protection voltage 25.5V because LED terminal can be 0V. After the over voltage protection is detected, LED terminal of 0V isn’t cut from feedback loop. Then, Output voltage will become normal voltage automatically.

2) When LED short-circuited in the plural All LED continue to be turned on, unless LED terminal voltage become more than “LED terminal over voltage protection (11.5V)”. When it was more than 11.5V, the line which short-circuited is only turned on, and LED current of other lines decrease or turn off.

3) When Schottky diode came off All LED aren't turned on. Also, IC isn't destroyed because boost operating stops by the Schottky diode coming off protected function.

4) When an output capacitor short. All LED aren't turned on. And, an IC isn't destroyed because boost stops by the SBD open protection function. But, big electric current occurs, and a coil or SBD is likely to destroy it because the route of the GND short circuit of the power supply  coil  output capacitor occurs.

5) When the resistance to connect it to the ISET terminal short. All LED aren't turned on. Because LED current limit works, all current drivers stop, and DC/DC maintains boost under the state without load. And, it is returned in a state of normality by canceling a state of short.

●Start control and select constant current driver

BD6586MUV can control the start conditions by EN1, 2 and PWM terminals, and sets 0.4V or below EN1, 2 terminals, so IC can power off. EN1,2 and PWM power on at more than 1.4V, constant current can select ON/OFF by the combination of EN as shown below table. When there is unused constant current driver, unused LED terminal is set “OPEN”.

Enable Constant current driver

EN1 EN2 PWM LED1 LED2 LED3 LED4

H H H OFF ON ON OFF ON

L H H OFF ON ON ON ON

H L H ON ON ON ON ON

L L H OFF OFF OFF OFF OFF

H H L OFF OFF OFF OFF ON

L H L OFF OFF OFF OFF ON

H L L OFF OFF OFF OFF ON

L L L OFF OFF OFF OFF OFF

IC POWER

Technical Note

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5/19

2011.6 - Rev.C

BD6586MUV

●Control Signal input timing

HI Voltage of

PWM, EN

2.7V

Technical Note

Stable voltage

VBAT

PWM

○

EN1,2

DC/DC VOUT

In case you input control signs, such as EN1, EN2 and PWM in the condition that the standup of supply voltage (VBAT) is not completed, be careful of the following point.

①Input each control signal after VBAT exceeds 2.7V. ②Please do not input each control sign until VBAT exceeds HI voltage of EN1, EN2 and PWM. ③When you input HI voltage to EN1, EN2 and PWM during the standup of VBAT, please give Min.100µs as the standup time

of VBAT from stable voltage to 2.7V.

There is no timing limitation at each input signal of EN1, EN2 and PWM. If each control sign changes into a condition lower than VBAT in (1) and (2), it goes via the ESD custody diode by the side of VBAT of each terminal. A power supply is supplied to VBAT and there is a possibility of malfunctioning. Moreover, when the entrance current to the terminal exceeds 50mA, it has possibility to damage the LSI. In order to avoid this condition, as shown in the above figure, please insert about 10k in a signal line, and apply current qualification.

●LED current setting range

LED current can set up Normal current by resistance value (RISET) connecting to ISET voltage. Setting of each LED current is given as shown below.

Normal current = 20mA(24k/RISET)

Also, Normal current setting range is 10mA~25mA. LED current becomes a leak current MAX 2µA at OFF setting.

ISET Normal current setting example

RISETH LED current

24k (E24) 20mA

25.5 k (E96) 18.8mA 27 k (E12) 17.8mA

28k (E96) 17.1mA

30k (E24) 16.0mA

33k (E6) 14.5mA

○

Fig.3 control Signal timing Fig.4 Voltage with a control sign higher than VBAT

Min. 100µs

○

HI Voltage of PWM

10k

Example corresponding to application of conditions

VBAT

300k

GND

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6/19

2011.6 - Rev.C

BD6586MUV

●Brightness control

There are two dimming method is available, first method is analog dimming that apply analog voltage to ISETH terminal, and second method is PWM control via digital dimming of EN1, EN2 PWM terminals or PWM. Because each method has the different merit, please choose a suitable method for the application of use. Refer to Fig.23 for the analog dimming. Two techniques can be used as digital dimming by the PWM control. One is PWM control of current driver, the other is PWM control of power control. As these two characteristics are shown in the below, selects to PWM control process comply with application.

•Efficiency emphasis in the low brightness which has an influence with the battery life  2) Power control PWM control

•LED current dispersion emphasis in the PWM brightness control  1) Current driver PWM control

(Reference)

PWM regulation process

Current driver 60% 0.1%

Power control 94% 0.6%

1) Current driver PWM control is controlled by providing PWM signal to PWM terminal, as it is shown Fig.5. The current set up with ISET is chosen as the H section of PWM and the current is off as the L section. Therefore, the average LED current is increasing in proportion to duty cycle of PWM signal. This method that it lets internal circuit and DC/DC to work, because it becomes to switch the driver, the current tolerance is a few when the PWM brightness is adjusted, it makes it possible to brightness control until 20µs (MIN0.4% at 200Hz). And, don't use for the brightness control, because effect of ISET changeover is big under 20µs ON time and under 20µs OFF time. There is no effect of ON/OFF changeover at 0% and 100%, so there is no problem on use. Typical PWM frequency is 100Hz~10kHz.

Efficiency of LED current 0.2mA

(PWM Duty=1%)

PWM frequency 200Hz

Low Duty

Technical Note

PWM

LED current

Coil current

IC’s active current

Fig.5 Current driver PWM control

2) Power control PWM control is controlled by providing PWM signal to EN1, EN2 as it is shown Fig.6. The current setting set up with PWM logic is chosen as the H section and the current is off as the L section. Therefore, the average LED current is increasing in proportion to duty cycle of EN1, EN2 signal. This method is, because IC can be power-off at off-time, the consumption current can be suppress, and the high efficiency can be available, so it makes it possible to brightness control until 50µs (MIN1% at 200Hz). And, don't use for the brightness control, because effect of power ON/OFF time changeover is big under 50µs ON time and under 50µs OFF time. There is no effect of ON/OFF changeover at 0% and 100%, so there is no problem on use. Typical PWM frequency is 100Hz~1kHz.

EN1,EN”

LED current

Coil current

IC’s active current

Fig.6 Power control PWM control

ON OFF

OFF

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7/19

2011.6 - Rev.C

BD6586MUV

Technical Note

●The separations of the IC Power supply and coil Power supply

This IC can work in separating the power source in both IC power supply and coil power supply. With this application, it can obtain that decrease of IC power consumption, and the applied voltage exceeds IC rating 5.5V.

That application is shown in below Fig.7. The higher voltage source is applied to the power source of coil that is connected from an adapter etc. Next, the IC power supply is connected with a different coil power supply.

When the coil power supply is applied, it is no any problem even though IC power supply is the state of 0V. Although IC power supply is set to 0V, pull-down resistance is arranged for the power off which cuts off the leak route from coil power supply in IC inside, the leak route is cut off. And, there is no power on-off sequence of coil power supply and IC power supply.

Other Power Supply

6V to 25V

4.7F

4.7H

2.2F

Power

ON/OFF

TRSW

EN2

EN1

PWM

TESTO

TEST ISET

PGND

GND

Battery

2.7V to 5.5V

VBAT

GND

VDET

LED1

LED2

LED3

LED4

24k

6LED x 4Parallel

Each 20mA

Fig.7 Each battery and coil power supply

●The coil selection

The DC/DC is designed by more than 4.7µH. When L value sets to a lower value, it is possibility that the specific sub-harmonic oscillation of current mode DC / DC will be happened.

Please do not let L value to 3.3µH or below.

And, L value increases, the phase margin of DC / DC becomes to zero. Please enlarge the output capacitor value when you increase L value.

Example)

4.7µH = output capacitor 2.2µF/50V 1pcs

6.8µH = output capacitor 2.2µF/50V 2pcs 10µH = output capacitor 2.2µF/50V 3pcs This value is just examples, please made sure the final judgment is under an enough evaluation.

●The adjustment of the switching wave form

A switching wave form between the coil and the switch terminal can be adjusted by connecting a capacitor to TRSW. Switching noise can be restrained though efficiency is made to decrease by connecting a capacitor. Decide capacity value after the enough evaluation when you adjust switching noise.

TRSW PGND

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TRSW

PGND

Fig.8 The adjustment of the switching wave form

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2011.6 - Rev.C

BD6586MUV

Technical Note

●PCB Layout

In order to make the most of the performance of this IC, its layout pattern is very important. Characteristics such as efficiency and ripple and the likes change greatly with layout patterns, which please note carefully.

to Power Supply

to Pow er Sup ply

to GND

SBD

OUT

to Anode of LED

VBAT

(100Hz~1000Hz)

PWM

RISET

VBA

EN1

EN2

LED6 LED5 L ED4 LED3LED2

GND

PWM

ISE

TRS

23 22

N.C.

PGND

Thermal Via

BD6586MUV

Thermal Via

21 20 19

PGND

N.C.

VDE

N.C.

TEST0

TEST

7 8 9 10 11 12

GND

LED1

LED2

GND

Fig.9 PCB Layout

Connect the input bypath capacitor CIN nearest to coil L and PGND, as shown in the upper diagram. Ripple of a power supply is smoothed by CIN and connect stable voltage to VBAT terminal by the low resistance. Thereby, the input voltage ripple of the IC can be reduced. Connect CVBAT nearest to between the VBAT terminal and GND (4 pin) as shown in the upper diagram when you can't be wired by the low resistance from CIN to VBAT pin Connect schottky barrier diode SBD of the regulator nearest to between coil L and SW terminal. And connect output capacitor COUT nearest to between CIN and GND pin. Thereby, the output voltage ripple of the IC can be reduced. GND terminal (4,7,10 pin) is connected inside the IC, and it is GND of the block except switching and a transistor. A current drive performance may be restricted by influence of a noise, if PGND which is not smooth connected to GND. A GND terminal is connected to the stable GND plane. And connect it to a GND plane after smoothing PGND by CIN and COUT. GND and PGND are separated inside IC. And connect it to a GND plane after smoothing PGND by CIN and COUT. Connect the heat sink of IC to a GND plane through Thermal Via. And Connect with the largest possible pattern. It is satisfactory even if it connects with the GND terminal of IC. Connect LED current setting resistor RISET nearest to ISET pin. There is possibility to oscillate when capacity is added to ISET terminal, so pay attention that capacity isn't added. And, RISET of GND side must be wired directly to GND(7pin) pin. When those pins are not connected directly near the chip, influence is given to the performance of BD6586MUV, and may limit the current drive performance. As for the wire to the inductor, make its resistance component small so as to reduce electric power consumption and increase the entire efficiency. A layout pattern in consideration of these is shown in p.12.

to Anode of each LED

LED3

LED4

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9/19

2011.6 - Rev.C

BD6586MUV

●Recommended PCB layout pattern

SBD

Coil

OUT

RISET

VBAT

Fig.10 Frontal surface <Top view>

Fig.11 Rear surface <Top view>

Technical Note

BD6586MUV

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10/19

2011.6 - Rev.C

BD6586MUV

●Selection of external parts

Recommended external parts are as shown below. When to use other parts than these, select the following equivalent parts. Coil

Value Manufacturer Product number

4.7H TOKO A915AY-4R7M 5.2 5.2 3.0 1870 0.045

4.7H TOKO B1015AS-4R7M 8.4 8.3 4.0 3300 0.038

4.7H TOKO A1101AS-4R7M 4.1 4.1 1.2 1400 0.115

4.7H TDK LTF5022T-4R7N2R0 5.0 5.2 2.2 2000 0.073 10H TDK LTF5022T-100M1R4 5.0 5.2 2.2 1400 0.140

4.7H TDK VLP6810T-4R7M1R6 6.3 6.8 1.0 1600 0.167 10H TDK VLP6810T-100M1R1 6.3 6.8 1.0 1100 0.350

Capacitor

Val ue Pressure Manufacturer Product number

[ Power supply capacitor ]

4.7F 25V MURATA GRM319B31E475K 3.2 1.6 0.85±0.1 B +/-10%

4.7F 25V MURATA GRM21BR61E475K 2.0 1.25 1.25±0.1 X5R +/-10% 1F 10V MURATA GRM188B11A105K 1.6 0.8 0.8±0.1 B +/-10%

4.7F 10V MURATA GRM219B31A475K 2.0 1.25 0.85±0.1 B +/-10%

[ Output capacitor ]

1F 35V MURATA GRM219B3YA105K 2.0 1.25 0.85±0.1 B +/-10% 1F 50V MURATA GRM31MB31H105K 3.2 1.6 1.15±0.1 B +/-10% 1F 50V MURATA GRM21BB31H105K 2.0 1.25 1.25±0.1 B +/-10%

2.2F 50V MURATA GRM31CB31H225K 3.2 1.6 1.6±0.2 B +/-10%

Resistor

Val ue Tolerance Manufacturer Product number

[ Resistor for LED current decision <ISET pin> ]

24k ±0.5% ROHM MCR006YZPD243 0.6 0.3 0.23±0.03

SBD

Pressure Manufacturer Product number

60V ROHM RB160M-60 3.5 1.6 0.8±0.1

The coil is the part that is most influential to efficiency. Select the coil whose direct current resistor (DCR) and current inductance characteristic is excellent. BD6586MUV is designed for the inductance value of 4.7µH. Don’t use the inductance value less than 2.2µH. Select a capacitor of ceramic type with excellent frequency and temperature characteristics. Further, select Capacitor to be used with small direct current resistance, and pay sufficient attention to the layout pattern shown in P.10.

●Attention point of PCB layout

In PCB layout design, the wiring of power supply line should be low Impedance, and put the bypass capacitor if necessary. Especially the wiring impedance must be lower around the DC/DC converter.

●About heat loss

In heat design, operate the DC/DC converter in the following condition. (The following temperature is a guarantee temperature, so consider the margin.)

1. Periphery temperature Ta must be less than 85

2. The loss of IC must be less than dissipation Pd.

℃.

Vertical Horizontal Height (MAX)

Vertical Horizontal Height

Size

Technical Note

DC current

(mA)

Tolerance

DCR

()

Cap

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11/19

2011.6 - Rev.C

BD6586MUV

●Application example ・LED current setting controlled ISET resistor.

24k : 20mA 30k : 16mA

19.6k : 24.5mA 33k : 14.5mA

・Brightness control

Please input PWM pulse from EN1, EN2 or PWM terminal. Please refer electrical function p.7.

7 inch panel

Battery

2.7V to 5.5V

100Hz~1kHz

PWM

4.7F

4.7H

PGND

TRSW

EN2

EN1

PWM

TESTO

TEST ISET

Fig.12 6 series×4 parallel, LED current 20mA setting

Power control PWM application

5inch panel

Battery

2.7V to 5.5V

4.7F

4.7H

Power

ON/OFF

100Hz~10kHz

PWM

TRSW

EN2

EN1

PWM

TESTO

PGND

TEST ISET

Fig.13 6 series×3 parallel, LED current 20mA setting

Current driver PWM application

2.2F

GND

PGND

GND

2.2F

GND

1F

GND

VBAT

GND

1F

VBAT

GND

VDET

LED1

LED2

LED3

LED4

24k

6LED x 4Parallel

Each 20mA

Can be set up to each 10~25mA

6LED x 3Parallel

VDET

LED1

LED2

LED3

LED4

24k

Each 20mA Can be set up to each 10~25mA

Technical Note

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12/19

2011.6 - Rev.C

BD6586MUV

●Application example ・LED current setting controlled ISET resistor.

24k : 20mA 30k : 16mA

19.6k : 24.5mA 33k : 14.5mA

・Brightness control

Please input PWM pulse from EN1, EN2 or PWM terminal. Please refer electrical function p.7.

5 inch panel

Battery

2.7V to 5.5V

4.7F

4.7H

Power

ON/OFF

100Hz~10kHz

PWM

PGND

TRSW

EN2

EN1

PWM

TESTO

TEST ISET

Fig.14 4 series×4 parallel, LED current 20mA setting

Current driver PWM application

Battery

2.7V to 5.5V

Power

ON/O FF

100Hz~ 10kHz

PWM

4.7F

4.7H

TRSW

EN2

EN1

PWM

TESTO

TEST ISET

PGN D

PGND

Fig.15 5 series×3 parallel, LED current 20mA setting

Current driver PWM application

2.2F

GND

2.2F

GND

1F

VBAT

GND

VBAT

GND

VDET

LED1

LED2

LED3

LED4

24k

VDET

LED1

LED2

LED3

LED4

24k

4LED x 4Parallel

Each 20mA Can be set up to each 10~25mA

5LED x 3Parall el

ach 20mA

Can be set up to each 10~25mA

Technical Note

www.rohm.com

13/19

2011.6 - Rev.C

BD6586MUV

●Application example ・LED current setting controlled ISET resistor.

24k : 20mA 30k : 16mA

19.6k : 24.5mA 33k : 14.5mA

・Brightness control

Please input PWM pulse from EN1, EN2 or PWM terminal. Please refer electrical function p.7.

Less than 5 inch panel

Battery

2.7V to 5.5V

4.7F

4.7H

Power

ON/OFF

100Hz~10kHz

PWM

TRSW

EN2

EN1

PWM

TESTO

PGND

TEST ISET

Fig.16 6 series×2 parallel, LED current 20mA setting

Current driver PWM application

Battery

2.7V to 5.5V

4.7F

4.7H

100Hz~1kHz

PWM

TRSW

EN2

EN1

PWM

TESTO

PGND

TEST ISET

Fig.17 6 series×2 parallel, LED current 40mA setting

Power control PWM application

PGND

2.2F

GND

2.2F

GND

1F

VBAT

GND

VBAT

GND

VDET

LED1

LED2

LED3

LED4

24k

VDET

LED1

LED2

LED3

LED4

24k

6LED x 2Parallel

Each 20mA Can be set up to each 10~25mA

6LED x 2Parallel

Each 40mA Can be set up to each 20~50mA

Technical Note

www.rohm.com

14/19

2011.6 - Rev.C

BD6586MUV

●Application example ・LED current setting controlled ISET resistor.

24k : 20mA 30k : 16mA

19.6k : 24.5mA 33k : 14.5mA

・Brightness control

Please input PWM pulse from EN1, EN2 or PWM terminal. Please refer electrical function p.7.

Less than 5 inch panel

Battery

2.7V to 5.5V

4.7F

4.7H

Power

ON/OFF

100Hz~10kHz

PWM

PGND

TRSW

EN2

EN1

PWM

TESTO

TEST ISET

Fig.18 2 series×3 parallel, LED current 20mA setting

Current driver PWM application

Battery

2.7V to 5.5V

4.7F

4.7H

100Hz~1kHz

PWM

TRSW

EN2

EN1

PWM

TESTO

TEST ISET

PGND

Fig.19 3 series×2 parallel, LED current 40mA setting

Power control PWM application

2.2F

GND

2.2F

GND

1F

VBAT

GND

VBAT

VDET

LED1

LED2

LED3

LED4

24k

VDET

LED1

LED2

LED3

LED4

24k

2LED x 3Parallel

Each 20mA Can be set up to each 10~25mA

6LED x 2Parallel

Each 40mA Can be set up to each 20~50mA

Technical Note

www.rohm.com

15/19

2011.6 - Rev.C

BD6586MUV

●Application example ・LED current setting controlled ISET resistor.

24k : 20mA 30k : 16mA

19.6k : 24.5mA 33k : 14.5mA

・Brightness control

Please input PWM pulse from EN1, EN2 or PWM terminal. Please refer electrical function p.7.

For big current LED

Battery

2.7V to 5.5V

4.7F

4.7H

Power

ON/OFF

100Hz~10kHz

PWM

PGND

TRSW

EN2

EN1

PWM

TESTO

TEST ISET

Fig.20 6 series×1 parallel, LED current 60mA setting

Current driver PWM application

Battery

2.7V to 5.5V

4.7F

4.7H

100Hz~1kHz

PWM

PGND

TRSW

EN2

EN1

PWM

TESTO

TEST ISET

Fig.21 6 series×1 parallel, LED current 80mA setting

Power control PWM application

2.2F

GND

2.2F

GND

1F

GND

1F

VBAT

GND

VDET

LED1

LED2

LED3

LED4

24k

VDET

24k

6LED x 1Parallel

Each 60mA Can be set up to each 30~75mA

6LED x 1Parallel

LED1

LED2

LED3

LED4

Each 80mA Can be set up to each 40~100mA

Technical Note

www.rohm.com

16/19

2011.6 - Rev.C

BD6586MUV

●Application example ・LED current setting controlled ISET resistor.

24k : 20mA 30k : 16mA

19.6k : 24.5mA 33k : 14.5mA

・Brightness control

Please input PWM pulse from EN1, EN2 or PWM terminal. Please refer electrical function p.7.

For the application of 7V and more

Other Power Supply

6.0Vto25V

4.7F

Power

ON/OFF

4.7H

2.2F

TRSW

EN2

EN1

PWM

TESTO

TEST ISET

PGND

GND

Fig.22 6 series×4 parallel, LED current 20mA setting

Power control PWM application

●Analog style optical application Control LED current to charged D/A voltage. Show application example and typ control. Please decide final value after you evaluated application, characteristic.

Power

ON/O FF

Battery

2.7V to 5.5V

4.7F

4.7H

2.2F

TRSW

EN2

EN1

PWM

TESTO

PGND

GND

PGND

TEST ISET

GND

1F

VBAT

GND

6LED x 4Parallel

VDET

LED1

LED2

LED3

LED4

ach 20mA

Can be set up to each 10~25mA

470

24k

D/A

Fig.23 Analog style optical application

Battery

2.7V to 5.5V

1F

VDET

VBAT

LED1

LED2

LED3

GND

LED4

24k

D/A LED current

0.05V 19.4mA

0.2V 14.4mA

0.4V 7.7mA

0.5V 4.4mA

0.6V 1.0mA

0.7V 0mA

LED current =

typ LED current =

6LED x 4Parallel

Each 20mA Can be set up to each 20~50mA

ISET voltage

470k

0.6V

470k

ISET voltage -D/

0.6V-D/A

Technical Note

24k

×800

www.rohm.com

17/19

2011.6 - Rev.C

BD6586MUV

●Notes for use

(1) Absolute Maximum Ratings

An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc., can break down devices, thus making impossible to identify breaking mode such as a short circuit or an open circuit. If any special mode exceeding the absolute maximum ratings is assumed, consideration should be given to take physical safety measures including the use of fuses, etc.

(2) Operating conditions

These conditions represent a range within which characteristics can be provided approximately as expected. The electrical characteristics are guaranteed under the conditions of each parameter.

(3) Reverse connection of power supply connector

The reverse connection of power supply connector can break down ICs. Take protective measures against the breakdown due to the reverse connection, such as mounting an external diode between the power supply and the IC’s power supply terminal.

(4) Power supply line

Design PCB pattern to provide low impedance for the wiring between the power supply and the GND lines. In this regard, for the digital block power supply and the analog block power supply, even though these power supplies has the same level of potential, separate the power supply pattern for the digital block from that for the analog block, thus suppressing the diffraction of digital noises to the analog block power supply resulting from impedance common to the wiring patterns. For the GND line, give consideration to design the patterns in a similar manner. Furthermore, for all power supply terminals to ICs, mount a capacitor between the power supply and the GND terminal. At the same time, in order to use an electrolytic capacitor, thoroughly check to be sure the characteristics of the capacitor to be used present no problem including the occurrence of capacity dropout at a low temperature, thus determining the constant.

(5) GND voltage

Make setting of the potential of the GND terminal so that it will be maintained at the minimum in any operating state. Furthermore, check to be sure no terminals are at a potential lower than the GND voltage including an actual electric transient.

(6) Short circuit between terminals and erroneous mounting

In order to mount ICs on a set PCB, pay thorough attention to the direction and offset of the ICs. Erroneous mounting can break down the ICs. Furthermore, if a short circuit occurs due to foreign matters entering between terminals or between the terminal and the power supply or the GND terminal, the ICs can break down.

(7) Operation in strong electromagnetic field

Be noted that using ICs in the strong electromagnetic field can malfunction them.

(8) Inspection with set PCB

On the inspection with the set PCB, if a capacitor is connected to a low-impedance IC terminal, the IC can suffer stress. Therefore, be sure to discharge from the set PCB by each process. Furthermore, in order to mount or dismount the set PCB to/from the jig for the inspection process, be sure to turn OFF the power supply and then mount the set PCB to the jig. After the completion of the inspection, be sure to turn OFF the power supply and then dismount it from the jig. In addition, for protection against static electricity, establish a ground for the assembly process and pay thorough attention to the transportation and the storage of the set PCB.

(9) Input terminals

In terms of the construction of IC, parasitic elements are inevitably formed in relation to potential. The operation of the parasitic element can cause interference with circuit operation, thus resulting in a malfunction and then breakdown of the input terminal. Therefore, pay thorough attention not to handle the input terminals, such as to apply to the input terminals a voltage lower than the GND respectively, so that any parasitic element will operate. Furthermore, do not apply a voltage to the input terminals when no power supply voltage is applied to the IC. In addition, even if the power supply voltage is applied, apply to the input terminals a voltage lower than the power supply voltage or within the guaranteed value of electrical characteristics.

(10) Ground wiring pattern

If small-signal GND and large-current GND are provided, It will be recommended to separate the large-current GND pattern from the small-signal GND pattern and establish a single ground at the reference point of the set PCB so that resistance to the wiring pattern and voltage fluctuations due to a large current will cause no fluctuations in voltages of the small-signal GND. Pay attention not to cause fluctuations in the GND wiring pattern of external parts as well.

(11) External capacitor

In order to use a ceramic capacitor as the external capacitor, determine the constant with consideration given to a degradation in the nominal capacitance due to DC bias and changes in the capacitance due to temperature, etc.

(12) Thermal shutdown circuit (TSD)

When junction temperatures become 175°C (typ) or higher, the thermal shutdown circuit operates and turns a switch OFF. The thermal shutdown circuit, which is aimed at isolating the LSI from thermal runaway as much as possible, is not aimed at the protection or guarantee of the LSI. Therefore, do not continuously use the LSI with this circuit operating or use the LSI assuming its operation.

(13) Thermal design

Perform thermal design in which there are adequate margins by taking into account the permissible dissipation (Pd) in actual states of use.

(14) Selection of coil

Select the low DCR inductors to decrease power loss for DC/DC converter.

Technical Note

www.rohm.com

18/19

2011.6 - Rev.C

BD6586MUV

●Ordering part number

Technical Note

B D

Part No. Part No.

VQFN024V4040

4.0±0.1

1.0MAX

0.08 S

C0.2

0.4±0.1

0.75

6 5 8 6

6586

4.0±0.1

1PIN MARK

2.4±0.1

0.5

0.02

+0.03

(0.22)

0.02

2.4±0.1

1318

+0.05

0.25

0.04

(Unit : mm)

MU V

Package

MUV: VQFN024V4040

Embossed carrier tapeTape

Quantity

Direction of feed

2500pcs 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

E 2

Packaging and forming specification E2: Embossed tape and reel

1pin

Order quantity needs to be multiple of the minimum quantity.

∗

Direction of feed

www.rohm.com

19/19

2011.6 - Rev.C

Notes

No copying or reproduction of this document, in par t 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.

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 injury, 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.

Notice

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ROHM BD6586MUV Technical data

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Frequently Asked Questions

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