ACE517

                                                                                           ACE517                                               Technology Description WLED Linear Driver for Li-lon Battery Application The ACE517 is a CMOS based White/Blue LED driver with stand-alone capability. The driver is primarily designed for LED backlighting of LCE display powered by Li-ion battery with its high efficiency, low standby current and wide range of input supply voltage, the ACE517 is suitable for applications such as portable device display and keypad backlighting. In portable application, three or four-channel LED solutions are popular, ACE517 has three LED channels with a SOT-23-6 package. ACE517 has four LED channels with a MSOP-8 package. Features • • • • • • • • • • No external component required PWM dimming control available Low noise and EMI LED sink current of 20mA Independent current sink circuit for each LED output Versatile supply voltage range Low standby current High accuracy current match on each channel Application Small Size Color LEC Backlights Driver Mobile Phone, Portable Device Keypad Backlights Driver Absolute Maximum Ratings Parameter Supply voltage Voltage of LEDn, EN pin Maximum Junction Temperature Operating Ambient Temperature Range Storage Temperature Range Max Unit -0.3 to 7 V -0.3 to 7 V O 125 C O -40 to 85 C -40 to 150 OC VER 1.2 1                                                                                             ACE517                                               Technology Packaging Type SOT-23-6 6 5 4 WLED Linear Driver for Li-lon Battery Application MSOP-8 876 5 1 2 3 1 23 4 Pin Vin Vss EN LED1 LED2 LED3 LED4 GND SOT-23-6 MSOP-8 1 3 2 1.4 3 6 5 4 2 8 7 6 5 Function Power Supply Chip enable pin. High level activates the chip. Connect the pin to Vcc if not used, do not leave this pin floating RGB or WLED cathode connection pin Analog ground. In ACE517, for good LED current match, it is recommended that the two GND pins should be tied together by external copper. Ordering information Selection Guide ACE517 XX + H Halogen - free Pb - free GM : SOT-23-6 OM: MSOP-8 VER 1.2 2                                                                                            ACE517                                               Technology Block Diagram WLED Linear Driver for Li-lon Battery Application Recommended Work Conditions Item Min Recommended Max Unit Supply Voltage Range 2.7 6 V Output sink current on each channel 25 mA Operating Temperature -25 85 ℃ Electrical Characteristics VDD=3.7V,TA=25℃, No Load, Input: VIH=3.7V, VIL=GND. (Unless otherwise noted) Parameter EN Pin “Low” Logic EN Pin “High” Logic EN Pin “Low” Input Current EN Pin “High” Logic Current LEDn Droput Voltage LEDn Sink Current LEDn Sink Current Deviation Quiescent Current Standby Supply Current Symbol VIL VIH IIL IIH VLEDL ILED ΔILEDn IQ ISTBY Conditions Min 1.7 -1 19 VEN=”1” VEN+”0” Typ Max Units 0.4 V V uA 1 uA 100 mV 20 21 Ma +/-3 % 250 400 uA  0.5 uA  VER 1.2 3                                                                                            ACE517                                               Technology Typical Application Circuit Li-Ion Battery WLED Linear Driver for Li-lon Battery Application VCC GND LED 1 LED 2 LED 3 EN On/Off Control LED 4 Only Available in ACE517 Detailed Description ACE517 works with a wide range of supply voltage, from 2.7V to 6V. 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. Due to its uniquely designed current regulator, ACE517 offer low output dropout and provide superior efficiency performance over standard inductive boost type and capacitive charge pump type LED driver. The EN pin controls the on/off state of the device. A high level state turns on the device and a low level turns off the device, results in the low off state current. This pin needs to be terminated since a floating level of the EN pin will cause the instability of the device. The sink current has a constant value of 20mA. The brightness of the LED can be adjusted by controlling the duty cycle of the ACE517 LEDn pin. Hence, in order to normally modulate the output of LEDn in every cycle, the width of dimming signal applied CE pin have to be no less than 6us. For example, when a dimming signal of 20KHz is applied, the minimum range of dimming is about 12%, that is , the average output current on each channel is 2.4mA. VER 1.2 4                                                                                            ACE517                                               Technology Typical Performance Characteristics Quiescent Current Supply Current (TA=25℃) WLED Linear Driver for Li-lon Battery Application Quiescent Current vs. Temperature (Vin=3.7V) Supply Voltage (V) Temperature (℃) ILED vs. Supply Voltage (Vin=3.7V, Vf=3.2V) ILED vs LEDn Dropout Voltage (Vin=3.7V) Supply Voltage (V) LEDn Dropout Voltage (V) ILED vs. Temperature Temperature (℃) VER 1.2 5                                                                                            ACE517                                               Technology Packing Information SOT-23-6 WLED Linear Driver for Li-lon Battery Application VER 1.2 6                                                                                            ACE517                                               Technology Packing Information MSOP-8 WLED Linear Driver for Li-lon Battery Application Symbol A A1 A2 A3 b b1 c c1 D E E1 e L L1 θ Millimeter Min Nom Max 1.10 0.05 0.15 0.75 0.85 0.95 0.30 0.35 0.40 0.29 0.38 0.28 0.30 0.33 0.15 0.20 0.14 0.152 0.16 2.90 3.00 3.10 4.70 4.90 5.10 2.90 3.00 3.10 0.65BSC 0.40 0.70 0.95BSC 。 0 8 VER 1.2 7                                                                                            ACE517                                               Technology WLED Linear Driver for Li-lon Battery Application Notes ACE does not assume any responsibility for use as critical components in life support devices or systems without the express written approval of the president and general counsel of ACE Electronics Co., LTD. As sued herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and shoes failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. ACE Technology Co., LTD. http://www.ace-ele.com/ VER 1.2 8