ACE709 0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter Description ACE709, is a high-efficiency, synchronous step-up switching regulators optimized for battery-powered applications. It supports up to 1A load current and allows the use of small, low cost inductors and MLCC capacitors. The ACE709 starts up as low as 0.9V input voltage and it has true-shutoff function (shut off output to zero voltage when CE pulled low) and real output short-circuit protection. These features make it ideal for USB interface power supply. Given its high efficiency, the ACE709 device is ideal for small portable applications powered by battery. It consumes as low as 40uA (3V input /3.3V output) at zero load. And its current consumption is less than 1uA in shutdown mode. Features Capable of Delivering 1A High Efficiency: Up to 92% Compatible with MLCC capacitor 1.8MHz Switching Frequency Low dropout 100% Duty operation 0.6V Reference for Low Output voltages True Shutoff and Short-Circuit Protection Logic Control Shutdown (IQ<1uA) Thermal shutdown and UVLO Application MID / Tablet PC Portable Power Bank Smartphone OTG Toy Other portable device Absolute Maximum Ratings Parameter Max Max Input Voltage 5.5 Unit V 125 O C Ambient Temperature(TA ) -40~85 O C Maximum Power Dissipation 800 Storage Temperature(Ts) -55~150 ESD (HBM) >2000 Max Operating Junction Temperature(TJ) mW O C V Note: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect device reliability. VER 1.2 1 ACE709 0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter Packaging Type DFN2*2-6 Top View DFN2*2-6 Description 1 CE 2 FB 3 VOUT Function Enable pin for the IC. Drive the pin to high to enable the part, and low to disable Feedback input. Connect an external resistor divider from the output to FB and GND to set the output to a voltage between 0.6V and Vin Output voltage pin, with 22uF ceramic capacitor closely connected to GND 4 GND Ground 5 LX To connect inductor to VIN 6 VIN Supply voltage, with 4.7uF ceramic capacitor connected to GND Ordering information ACE709 XX + H Halogen - free Pb - free KN : DFN2*2-6 Recommended work conditions Parameter Input Voltage Range Max Unit 5 Operating Junction Temperature(TJ) -40~85 V O C VER 1.2 2 ACE709 0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter Block Diagram Electrical Characteristics O VDD=5V, TA=25 C Symbol Parameter Test Conditions Min Typ Max Unit VDD Input Voltage Range 5 V Vstart Startup Voltage Iout = 0 A 0.9 1.0 V Vref Feedback Voltage Vout = 2.5 to 5V 0.6 0.615 Ifb Feedback Leakage current 0.1 0.4 Vout Output Voltage Range Iq Quiescent Current Irev Reverse current, Vout to Vin Fsoc Switching Frequency 1.8 RDS(ON) P PMOS RDS(ON) 150 300 mΩ RDS(ON) N NMOS RDS(ON) 150 300 mΩ Llimit Peak Current Limit 1.5 2 A Ilxlk LX Leakage Current 10 uA Icelk CE Leakage Current 1 uA Vh_en EN Input High Voltage Vl_en EN Input Low Voltage TSD Thermal Shut Down 0.9 0.585 2.1 5 V Active, Vfb=0.7, No Switching 40 60 uA Shutdown 1 10 uA 5 uA CE=0 1.2 LX=5V, CE=0 MHz 0.6 V 0.3 150 V O C VER 1.2 3 ACE709 0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter Typical Application Circuit Typical Performance Characteristics O Tested under TA=25 C, L=6.8uH, unless otherwise specified VER 1.2 4 ACE709 0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter Typical Performance Characteristics O Tested under TA=25 C, L=6.8uH, unless otherwise specified VER 1.2 5 ACE709 0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter Detailed description General description The ACE709 is a high-efficiency, Boost DC/DC converter, with input current limit at 1.5A. It integrates an 150mΩ high side MOSFET and an 150 mΩ low side MOSFET. It employs PWM/PFM auto-switch control mode. Short circuit protection ACE709 employs a “Hiccup” mode of short-circuit protection, which enables output voltage auto recover when short-circuit is removed. True shut off function ACE709 offers a true shut off function, which means it can really shut off output (make output voltage to zero) when CE is pull low (chip turns off). Normally, there is a schottky diode (or MOSFET body diode) existed between LX and Vout for a normal boost converter, and thus, when CE is pull low, though the chip is turned off, the Vin is connected to Vout thru inductor and schottky diode. So we still can detect a voltage at Vout terminal. ACE709, with its proprietary design skill, can truly shut down the output when chip is turned off. Design Procedure Setting Output Voltages Output voltages are set by external resistors. The FB_ threshold is 0.6V. RTOP = RBOTTOM[(VOUT / 0.6) - 1] Capacitor Selection A 22uF ceramic capacitor is demanded on output terminal, while 4.7uF is good enough for input. Higher values, lower cost ceramic capacitors are now becoming available in smaller case sizes. Their high ripple current, high voltage rating and low ESR make them ideal for switching regulator applications. Using ceramic capacitors can achieve very low output ripple and small circuit size. When choosing the input and output ceramic capacitors, choose the X5R or X7R dielectric formulations. These dielectrics have the best temperature and voltage characteristics of all the ceramics for a given value and size. Application Information Layout is critical to achieve clean and stable operation. The switching power stage requires particular attention. Follow these guidelines for good PC board layout: 1. Place 22uF output capacitors as close to the IC VOUT and GND pins as possible 2. Connect input and output capacitors to the same power ground node with a star ground configuration then to IC ground. 3. Keep the high-current paths as short and wide as possible. Keep the path of switching current short. Avoid vias in the switching paths. 4. If possible, connect VIN, SW, and GND separately to a large copper area to help cool the IC to further improve efficiency and long-term reliability. 5. Ensure all feedback connections are short and direct. Place the feedback resistors as close to the IC as possible. 6. Route high-speed switching nodes away from sensitive analog areas VER 1.2 6 ACE709 0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter Packing Information DFN2*2-6 VER 1.2 7 ACE709 0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter 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