BD6581GU-E2 Rohm Semiconductor, BD6581GU-E2 Datasheet
BD6581GU-E2
Specifications of BD6581GU-E2
Available stocks
Related parts for BD6581GU-E2
BD6581GU-E2 Summary of contents
Page 1
... BD6581GU ●Description BD6581GU is white LED driver IC with PWM step-up DC/DC converter that can boost max 42.5V and current driver that can drive max 25mA. The wide and precision brightness can be controlled by external PWM pulse. BD6581GU has very accurate current drivers, and it has few current errors between each strings. ...
Page 2
... BD6581GU ●Electrical Characteristic(Unless otherwise specified, VBAT=12V, RSTB=2.5V +25 ℃) Parameter [FAILSEL,PWMDRV Terminal] EN threshold voltage (Low) EN threshold voltage (High threshold voltage (High terminal input current [PWMPOW Terminal] Low Input Voltage range High Input Voltage range1 High Input Voltage range2 PWM pull down resistor ...
Page 3
... BD6581GU ●Reference Data 4.5 85 ℃ ℃ 3.5 3 2.5 2 -30 ℃ 1 VBAT [V] Fig.1 Current Consumption vs VBAT 2.3 2.28 2.26 2.24 2.22 2.2 125 -60 25 110 Fig.4 UVLO vs Temperature 16V 14 12V Ta=-50,+25,+125℃ Duty (%) Fig.7 LED current vs PWMDRV-HI Duty PWM = 200Hz ...
Page 4
... BD6581GU 3.0 2.0 Max Matching = Max LED Current/Average Current 1.0 0.0 -1.0 Min Matching = Min LED Current/Average Current -2.0 -3.0 0% 20% 40% 60% 80% 100% PWM HI Duty (%) Fig.13 LED current matching vs PWMDRV-HI Duty PWM = 200Hz 3.0 2.0 1.0 Max Matching = Max LED Current/Average Current ...
Page 5
... BD6581GU ●Package Outline www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. BD6581 LOT No. 5/26 Technical Note Number 2010.03 - Rev.A ...
Page 6
... BD6581GU ●Block Diagram, I/O Equivalent Circuit Diagram VBAT VREG RSTB 300kΩ PWMPOW REG Internal Power suplly 500kΩ TSD SBD Open protect FAILSEL over voltage protect 300kΩ S PWMcomp Control SW sence - 1MΩ SENSP + Current 100KΩ Sence SENSN TEST 100kΩ ...
Page 7
... BD6581GU ●Application Example Battery 4.7μH 10μF 2.2μF * RTR020N05 SW FAILSEL SENSP 100mΩ SENSN Power RSTB ON/OFF LED1 PWMPOW LED2 PWMDRV 200Hz PWM LED3 VBAT LED4 VREG LED5 1μF TEST ISETH ISETL GND GND GND GND LED6 24kΩ Fig.25 10 series x 6parallel Hi current 20mA setting ...
Page 8
... Functions 1) PWM current mode DC/DC converter While BD6581GU is power ON, the lowest voltage of LED1 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 ...
Page 9
... MAX current = 130mV / 70mΩ = 1.86A <The estimate of the current value which need for the normal operation > As over current detector of BD6581GU is detected the peak current, it have to estimate peak current to flow to the coil by operating condition. In case of, ○ Supply voltage of coil = VIN ○ ...
Page 10
... BD6581GU (Example 2) In case of, VIN=12.0V, L=4.7µH, fsw=1MHz, VOUT=39V, IOUT=80mA, Efficiency=85% Ipeak = (12.0V / 4.7µ 1MHz) x (1-(12V / 39V)) =1.77A Iave = (39V x 80mA / 12.0V) / 85% = 0.31A Ton = (0.31A x (1- 39V 1MHz 4.7µH / (1-VIN/VOUT) x (1/fsw)=0.69µs > Ton Peak current = 12V/4.7µH x 0.41µs = 1.05A *When too large current is set, output overshoot is caused, be careful enough because it is led to break down of the IC in case of the worst ...
Page 11
... This information can be reset by setting RSTB at 0V. ●Start Control and Select LED Current Driver BD6581GU can control the IC system by RSTB, and IC can power off compulsory by setting 0.2V or below. Also, It powers on PWMPOW is at more than 1.4V and RSTB is at more than 2.25V. ...
Page 12
... BD6581GU ●Start to Use PWMPOW Terminal for the PWM Control, PWM Operating After RSTB and PWMDRV is changing L → H, input PWM to PWMPOW terminal. There is no constraint in turn of RSTB and PWMDRV. And, because it corresponds to PWM drive of shorter ON time than soft start time (1ms), when PWMPOW is input H more than three times, the soft start is invalidated and it enable to correspond the high-speed drive ...
Page 13
... BD6581GU ●Start to Use PWMDRV Terminal for the PWM Control, PWM Operating After RSTB and PWMPOW is changing L → H, input PWM to PWMDRV terminal. There is no constraint in turn of RSTB and PWMPOW. After RSTB and PWMPOW is changing L → follows Fig.37, when it is not input PWM to PWMDRV pin but input L, boost of DC/DC is unstable state because current driver doesn’ ...
Page 14
... BD6581GU ●Brightness Control There are two dimming method is available, first method is analog dimming that apply analog voltage to ISET terminal, and second method is PWM control via digital dimming of PWMPOW or PWMDRV. Because each method has the different merit, please choose a suitable method for the application of use. ...
Page 15
... BD6581GU ●LED Current Setting Range LED current can set up Normal and Starting setting current. LED current can set up Normal current by resistance value (RISETH) connecting to ISETH voltage and LED current can set Starting current by resistance value (RISETL) connecting to ISETL voltage. Setting of each LED current is given as shown below. ...
Page 16
... ISET terminal, so pay attention that capacity isn't added. And, RISET of GND side must be wired directly to GND pin. When those pins are not connected directly near the chip, influence is given to the performance of BD6581GU, and may limit the current drive performance. As for the wire to the inductor, make its resistance component small reduce electric power consumption and increase the entire efficiency ...
Page 17
... ROHM 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. BD6581GU is designed for the inductance value of 4.7µH. inductance value less than 2.2 µH. characteristics. Further, select Capacitor to be used with small direct current resistance, and pay sufficient attention to the layout pattern shown in P ...
Page 18
... BD6581GU ●Attention point of board layout In board pattern 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. ...
Page 19
... BD6581GU ●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 ...
Page 20
... BD6581GU ●Application Example LED current setting controlled ISETH resistor. 24kΩ : 20mA 30kΩ : 16mA 19.6kΩ : 24.5mA 33kΩ : 14.5mA Brightness control Please input PWM pulse from PWMPOW or PWMDRV terminal. Please refer electrical characteristic p.3 and function (p.12). ...
Page 21
... BD6581GU LED current setting controlled ISETH resistor. 24kΩ : 20mA 30kΩ : 16mA 19.6kΩ : 24.5mA 33kΩ : 14.5mA Brightness control Please input PWM pulse from PWMPOW or PWMDRV terminal. Please refer electrical characteristic p.3 and function (p.12). 10~12inch panel Battery 4.7μ ...
Page 22
... BD6581GU LED current setting controlled ISETH resistor. 24kΩ : 20mA 30kΩ : 16mA 19.6kΩ : 24.5mA 33kΩ : 14.5mA Brightness control Please input PWM pulse from PWMPOW or PWMDRV terminal. Please refer electrical characteristic p.3 and function (p.12). 7inch panel Battery 4.7μ ...
Page 23
... BD6581GU LED current setting controlled ISETH resistor. 24kΩ : 20mA 30kΩ : 16mA 19.6kΩ : 24.5mA 33kΩ : 14.5mA Brightness control Please input PWM pulse from PWMPOW or PWMDRV terminal. Please refer electrical characteristic p.3 and function (p.12). 5inch panel Battery 4.7μ ...
Page 24
... BD6581GU LED current setting controlled ISETH resistor. 24kΩ : 20mA 30kΩ : 16mA 19.6kΩ : 24.5mA 33kΩ : 14.5mA Brightness control Please input PWM pulse from PWMPOW or PWMDRV terminal. Please refer electrical characteristic p.3 and function (p.12). For the application of 22V and more ...
Page 25
... BD6581GU Control LED current to charged D/A voltage. Show application example and typ control. Please decide final value after you evaluated application, characteristic. Battery 4.7μH 10μF 2.2μF * RTR020N05 SW FAILSEL VDET SENSP 51mΩ SENSN Power RSTB ON/OFF LED1 PWMPOW LED2 ...
Page 26
... BD6581GU ●Ordering part number Part No. Part No. VCSP85H2 (BU8920GU) 1PIN MARK 2.75±0.05 0.08 S 23- φ 0.30±0.05 0. φ 0.15)INDEX POST 0.375±0.05 P=0.5×4 www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved Package GU: VCSP85H2 <Tape and Reel information> Tape Embossed carrier tape ...
Page 27
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 ...