BL8581A PWM or Singl-Wire Dimming, 4-Channels WLED Linear Driver DESCRIPTION FEATURES The BL8581A is a CMOS based White/Blue LED driver with stand-alone capability. The driver is primarily designed for LED backlighting of LCD display powered by Li-ion battery With its high efficiency, low standby current and wide range of input supply voltage, the BL8581A is suitable for applications such as portable device display and keypad backlighting. It can realize PWM or single-wire dimming control through EN pin. • • • • • • • BL8581A has four LED channels with MSOP8 or QFN 3X3 -16 package. APPLICATIONS • • TYPICAL APPLICATION www.belling.com.cn 2.7 to 5.5V input range Single-wire dimming control with linear 16- steps PWM dimming control LED sink current of max. 20mA Independent current sink circuit for each LED output Low standby current High accuracy current match on each channel 1 Small Size Color LCD Backlights Driver Mobile Phone, Portable DeviEN Keypad Backlights Driver BL8581A MARKING INFORMATION ORDERING INFORMATION Product Classification Marking BL8581A □ 1 □ 2 □ 3 BL8581ACE8TR Code 1 □ LED1 LED2 2 LED LED3 3 LED4 LED1 LED LED4 8 5 6 7 KB: Product Code KB YY: LOT No. YYBZZ B: FAB Code ZZ: Date Code 2 □ KB YYBNN 1 GND 2 EN 3 VCC 3 □ 4 GND PIN DESCRIPTION Top view Product Classification Marking BL8581ACJKATR NC 16 NC 15 NC 14 Description Temperature&Rohs: C: -40~85°C, Pb Free Rohs Std. Package type: E8: MSOP-8 JKA: QFN 3X3 –16 JKB: QFN 3X3 –16 JKC: QFN 3X3 –16 Packing type: TR:Tape&Reel (Standard) Name LED1 LED1 13 LED1-LED4 LED2 12 LED2 NC 1 EN NC 2 KBA: Product Code KBA YY: LOT No YYBZZ B: FAB Code ZZ: Date Code 11 LED3 LED3 KBA YYBNN VCC GND NC LED4 10 LED4 NC 3 NC 4 9 NC 5 6 7 8 GND GND VCC EN ABSOLUTE MAXIMUM RATING Top view Product Classification Marking NC 15 GND VCC 14 13 12 NC NC 1 NC 2 KBB: Product Code KBB YY: LOT No YYBZZ B: FAB Code ZZ: Date Code –0.3V to 7V –0.3V to Voltage of LEDn, EN pin 7V Maximum Junction Temperature 125°C –40°C to Operating Ambient Temperature Range 85°C –40°C to Storage Temperature Range 150°C Lead Temperature (Soldering, 10 sec) 260°C Supply voltage BL8581ACJKBTR EN 16 11 NC KBB YYBNN LED1 LED1 3 10 NC LED2 LED2 4 9 NC 5 6 LED3 LED3 LED4 LED4 7 8 NC NC Note: Exceed these limits to damage to the device. Note: Exposure to absolute maximum rating conditions may affect device reliability. Top view Product Classification Marking BL8581ACJKCTR NC 16 EN 15 RECOMMENDED OPERATING CONDITIONS GND VCC 14 13 Items Supply Voltage Range Operating Temperature 12 NC NC 1 NC 2 KBC: Product Code KBC YY: LOT No YYBZZ B: FAB Code ZZ: Date Code 11 NC KBC YYBNN LED1 LED1 3 10 NC LED2 LED2 4 9 NC 5 6 7 LED3 LED3 LED4 LED4 GND 8 VCC Top view www.belling.com.cn Function Description RGB or WLED Cathode Connection Pin Chip Enable and Dimming Control Power Supply Ground Not Connected 2 MIN 2.7 -25 MAX 5.5 85 Unit V ℃ BL8581A BLOCK DIAGRAM VCC EN LED1 LED1 LED2 LED2 LED4 LED4 LED3 LED3 Enable Shunt Regulator GND ELECTRICAL CHARACTERISTICS VCC=3.7V, Ta=25°C, No Load, Input: VEN=3.7V. (Unless otherwise noted) Symbols Parameters VIL VIH IIL IIH Td EN Pin “Low” Logic EN Pin “High” Logic EN Pin “Low” Input Current Tlat Tpulse VLEDL ILED ∆ILEDn IQ ISTBY Conditions MIN TYP MAX Unit 0.4 1.7 -1 µA EN Pin “High” Input Current 1 PWM dimming control delay time Latch off time before transient to the new current level (see figure 2) Required positive and negative pulse Pulse dimming 4 width control LEDn Dropout Voltage LEDn Sink Current 18 LEDn Sink Current Deviation -3 Quiescent Current www.belling.com.cn VEN=”0” 3 µA 20 µS 20 µS 100 20 250 Standby Supply Current V V 0.5 20 µS 22 3 mV mA % 400 µA µA BL8581A DETAILED DESCRIPTION BL8581A works with a wide range of supply voltage, from 2.7V to 5.5V. The forward voltage of commercial white/blue LED is in the range of 2.9V to 3.5V at a current level of 20mA. Proper selection of the LED to match the supply voltage can fully utilize the Li-ion battery. For example, there is 1% ~ 3 % power left in the Li-ion battery when its voltage reaches 3.275V. So a LED with a forward voltage value of 3.2V can use up to 99% of the battery power under normal working condition. When the voltage of the battery drops below 3.2V, the current through the LED (hence the brightness) starts to decrease. pulse width wider than 20uS is regarded as a signal to stop the build-in counter. The time between two wide high levels (more than 20uS) is a counting period. When some rise edges occur between two high level pulses of 20us, the equation as shown below can calculate the active pulse number, called Code_No. Code _ No = Mod ( N ,16) , In the equation, N is the number of rise edges of the input waveform and mod function returns the remainder of N divided by 16. For example, if N=0, 16, or other integral multiple of 16, the mod function returns a value of 0, if N=1, 17 or other integral multiple of 16 plus 1, the mod function returns a value of 1, and so on. Startup sequence BL8581A starts to work only when VCC powered on and the EN pin became high after a delay, the delay time is at least 4us. EN pin is not allowed to connect to VCC directly or keep it floating. The relationship between LEDs’ brightness and the Code_No is listed as the following table. PWM dimming control Code No 0 1 2 3 4 5 6 7 If the frequency of the PWM signal to the EN pin is less than 5KHz, the average LED current is proportional to the duty cycle of the PWM signal, and the EN works as a simple on/off control. A high level turns on and a low shuts down the LEDs. There is a delay time between the input PWM signal and the output LED current waveform, as shown in Fig.1, the TD is about 20uS. ON duty ISET/20mA 0 15/15 14/15 13/15 12/15 11/15 10/15 9/15 Code No 8 9 10 11 12 13 14 15 ISET/20mA 8/15 7/15 6/15 5/15 4/15 3/15 2/15 1/15 The frequency of the input pulse should be lower than 100KHz, and the width of the high level and low level larger than 4uS to prevent false trigger. EN Td=20uS Td=20uS 20mA Code_No=1 I_LED Code_No=4 Fig. 1 PWM Dimming Control Single-wire dimming control EN The LEDs’ brightness can also be controlled by the pulses applied to the EN pin, Refer to the Fig. 2. Inside the device there is a 4-bit counter connecting to the EN pin. The LED current can be programmed up to 16 levels depends on the number of rise edges of the input waveform. A high level input (“1”) with www.belling.com.cn I_LE D 20uS 20uS Iset/20mA=15/15 Iset/20mA=12/15 Fig. 2 Single-Wire Dimming Control 4 BL8581A TYPICAL PERFORMANEN CHARACTERISTICS Quiescent Current vs Temperature (VCC=3.7V) 350 450 300 400 Quiescent Current (uA) Quiescent Current (uA) Quiescent Current vs Supply Current (Ta=25℃) 250 200 150 100 50 0 3.0 350 300 250 200 150 100 50 0 3.5 4.0 4.5 5.0 -40 -20 0 Supply Voltage (V) 40 60 80 100 120 140 Temperature (℃) ILED vs Supply Voltage ILED vs LEDn Dropout Voltage (VCC=3.7V) (VCC=3.7V, VLEDn=3.2V) 22 25 20 20 LED Current (mA) ILED (mA) 20 18 16 14 15 10 12 5 10 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 0 0.01 0.1 Supply Voltage (V) 1 10 LEDn Dropout Voltage (V) LED Current VS Code_No ILED vs Temperature (VCC=3.7V) 16 LED Current(mA) ILED (mA) 20 20.2 20.2 20.1 20.1 20.0 20.0 19.9 19.9 19.8 19.8 19.7 12 8 4 0 -50 -25 0 25 50 75 100 0 125 4 6 8 Code_No Temperature (℃) www.belling.com.cn 2 5 10 12 14 16 BL8581A PACKAGE INFORMATION Package MSOP-8 Devices per reel 3000Pcs Unit mm Package specification： Symbol Dimension (mm) MIN NOM MAX A - - 1.10 A1 0.05 A2 0.75 A3 Symbol Dimension (mm) MIN NOM MAX D 2.90 3.00 3.10 0.15 E 4.70 4.90 5.10 0.85 0.95 E1 2.90 3.00 3.10 0.30 0.35 0.40 e b 0.29 - 0.38 L b1 0.28 0.30 0.33 L1 c 0.15 - 0.20 θ c1 0.14 0.152 0.16 www.belling.com.cn 6 0.65BSC 0.40 - 0.70 0.95BSC 0 - 8° BL8581A PACKAGE INFORMATION Package QFN3X3-16 www.belling.com.cn Devices per reel 7 3000 Unit mm