AAT3112IVN-5.0-T1

500mA High Efficiency Charge Pump for White LED Flash Applications General Description The AAT3112 is a member of AnalogicTech's Total Power Management IC™ (TPMIC™) family. It is a dual voltage doubling charge pump that provides a regulated output voltage. It operates with an input voltage range of 2.7 to 5.0 volts. The device can deliver a constant 200mA output load current and up to 500mA of pulsed current. The 500mA peak current capability of the AAT3112 makes it ideal for white LED flash applications. A low external parts count (two 1μF flying capacitors and two small capacitors at VIN and VOUT) makes the AAT3112 ideally suited for small battery-powered applications. The AAT3112 has a thermal management system to protect the device in the event of a short-circuit condition at the output pin. Built-in soft-start circuitry prevents excessive inrush current during startup. A high charge pump switching frequency enables the use of very small external capacitors. A low current shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1μA. The AAT3112 is available in a Pb-free 16-pin 3x3mm QFN package and is rated over the -40°C to +85°C temperature range. AAT3112 Features • • • • • • • • • • • • ChargePump™ Input Voltage Range: — AAT3112-5.0: 2.7V to 5.0V — AAT3112-4.5: 2.7V to 4.5V Up to 500mA Peak Output Current 200mA Continuous Output Current IQ 4.0V) Efficiency vs. Input Voltage 85 80 Maximum Current Pulse (mA) 800 700 600 500 400 300 3 3.2 3.4 3.6 3.8 4 4.2 50mA Efficiency (%) 75 70 65 60 55 50 45 40 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 200mA 100mA Input Voltage (V) Input Voltage (V) 6 3112.2007.01.1.5 500mA High Efficiency Charge Pump for White LED Flash Applications Typical Characteristics- AAT3112-4.5V VIN = 3.5V, CIN = COUT = 10μF, C1 = C2 = 1μF; TA = 25°C, unless otherwise noted. AAT3112 Load Transient Response (VIN = 3.0V) IOUT (200mA/div) Load Transient Response (VIN = 4.2V) IOUT (200mA/div) VOUT (20mV/div) VOUT (20mV/div) Time (50µs/div) Time (50µs/div) Input and Output Ripples (IOUT = 50mA @ VIN = 3.5V) Input and Output Ripples (IOUT = 100mA @ VIN = 3.5V) VIN AC Coupled (20mV/div) VOUT AC Coupled (20mV/div) VIN AC Coupled (20mV/div) VOUT AC Coupled (20mV/div) Time (5µs/div) Time (5µs/div) Output Current vs. Input Voltage (500ms Pulse Time; VOUT > 4.0V) 800 800 Output Current vs. Input Voltage (70°C) (VOUT > 4.0V) 50ms 700 600 500 400 300 200 100 0 2.5 3.0 3.5 4.0 4.5 200ms 300ms 500ms 100ms Output Current (mA) 700 600 500 400 300 200 100 0 2.5 3 3.5 4 4.5 Input Voltage (V) Output Current (mA) Input Voltage (V) 3112.2007.01.1.5 7 500mA High Efficiency Charge Pump for White LED Flash Applications Typical Characteristics- AAT3112-4.5V VIN = 3.5V, CIN = COUT = 10μF, C1 = C2 = 1μF; TA = 25°C, unless otherwise noted. Output Voltage vs. Input Voltage for Pulsed High Current (IOUT = 500mA) 5 4.5 AAT3112 50ms Pulse 500ms Pulse Output Voltage (V) 4 3.5 3 2.5 2 1.5 1 0.5 0 3 3.2 3.4 3.6 3.8 4 4.2 Input Voltage (V) 8 3112.2007.01.1.5 500mA High Efficiency Charge Pump for White LED Flash Applications Typical Characteristics- AAT3112-5.0V VIN = 3.5V, CIN = COUT = 10μF, C1 = C2 = 1μF; TA = 25°C, unless otherwise noted. AAT3112 Output Voltage vs. Output Current 5.5 30 Supply Current vs. Supply Voltage (No Load, No Switching) Supply Current (μA) 5.4 Output Voltage (V) 5.3 5.2 5.1 5.0 4.9 4.8 4.7 4.6 4.5 0 50 100 150 200 250 300 VIN = 3.6V VIN = 4.2V VIN = 3.9V 25 20 15 10 5 0 2.5 3.0 3.5 4.0 4.5 5.0 Output Current (mA) Supply Voltage (V) Startup Time with 100mA Load Startup Time with 200mA Load EN (2V/div) EN (2V/div) VOUT (1V/div) VOUT (1V/div) Time (50µs/div) Time (50µs/div) Maximum Current Pulse vs. Input Voltage (50ms pulse; VOUT > 4.5V) 95 90 85 80 75 70 65 60 55 50 400 300 3.0 45 40 3.2 3.4 3.6 3.8 4.0 4.2 2.7 3.0 Efficiency vs. Input Voltage 100mA Maximum Current Pulse (mA) 1000 900 800 700 600 500 Efficiency (%) 200mA 50mA 3.3 3.5 3.8 4.1 4.4 4.7 4.9 Input Voltage (V) Input Voltage (V) 3112.2007.01.1.5 9 500mA High Efficiency Charge Pump for White LED Flash Applications Typical Characteristics- AAT3112-5.0V VIN = 3.5V, CIN = COUT = 10μF, C1 = C2 = 1μF; TA = 25°C, unless otherwise noted. AAT3112 Load Transient Response (VIN = 3.0V) Load Transient Response (VIN = 4.2V) IOUT (200mA/div) IOUT (200mA/div) VOUT (20mV/div) VOUT (20mV/div) Time (50µs/div) Time (50µs/div) Input and Output Ripples (IOUT = 50mA @ VIN = 3.5V) Input and Output Ripples (IOUT = 100mA @ VIN = 3.5V) VIN AC Coupled (20mV/div) VOUT AC Coupled (20mV/div) VIN AC Coupled (20mV/div) VOUT AC Coupled (20mV/div) Time (5µs/div) Time (5µs/div) Output Current vs. Input Voltage (500ms Pulse Time; VOUT > 4.5V) 1000 800 900 Output Current vs. Input Voltage (70°C) (VOUT > 4.5V) 700 600 500 400 300 200 100 0 200ms 300ms 500ms 50ms 100ms Output Current (mA) 800 700 600 500 400 300 200 100 0 3.0 3.5 4.0 4.5 5.0 Output Current (mA) 2.5 3.0 3.5 4.0 4.5 Input Voltage (V) Input Voltage (V) 10 3112.2007.01.1.5 500mA High Efficiency Charge Pump for White LED Flash Applications Typical Characteristics- AAT3112-5.0V VIN = 3.5V, CIN = COUT = 10μF, C1 = C2 = 1μF; TA = 25°C, unless otherwise noted. AAT3112 Output Voltage vs. Input Voltage for Pulsed High Current 6 (IOUT = 500mA) Output Voltage (V) 5 50ms Pulse 4 3 500ms Pulse 2 1 0 3.0 3.2 3.4 3.6 3.8 4.0 4.2 Input Voltage (V) 3112.2007.01.1.5 11 500mA High Efficiency Charge Pump for White LED Flash Applications Functional Block Diagram AAT3112 VIN S2 S1 C1 + EN1 Control Circuit S4 S3 C1 - VOUT1 Control Circuit EN2 GND S1 S2 C2+ C2S3 S4 VOUT2 Functional Description The AAT3112 is a dual charge pump intended for high-current applications. This device boosts an input voltage to a regulated output voltage. Regulation is achieved by sensing the output voltage through an internal resistor divider network. The AAT3112 requires only four external components: two 1.0μF ceramic capacitors for the charge pump (C1 and C2), one 10μF ceramic capacitor for CIN, and one 10μF ceramic capacitor for COUT. The AAT3112 is designed to deliver 200mA of continuous current and up to 500mA of pulsed current. Each charge pump engine has an independent enable pin to extend battery life. The charge pump switching frequency is approximately 750kHz, enabling the use of small external flying capacitors. The AAT3112 has complete output short-circuit and thermal protection to safeguard the device under extreme operating conditions. An internal thermal protection circuit senses die temperature and will shut down the device if the internal junction temperature exceeds approximately 145°C. 12 3112.2007.01.1.5 500mA High Efficiency Charge Pump for White LED Flash Applications Applications Information Charge Pump Efficiency The AAT3112 is a regulated output voltage doubling charge pump. The efficiency (η) can simply be defined as a linear voltage regulator with an effective output voltage that is equal to two times the input voltage. Efficiency (η) for an ideal voltage doubler can typically be expressed as the output power divided by the input power: AAT3112 Capacitor Characteristics Ceramic composition capacitors are highly recommended over all other types of capacitors for use with the AAT3112. Ceramic capacitors offer many advantages over their tantalum and aluminum electrolytic counterparts. A ceramic capacitor typically has very low ESR, is lowest cost, has a smaller PCB footprint, and is non-polarized. Low ESR ceramic capacitors help to maximize charge pump transient response. Since ceramic capacitors are non-polarized, they are not prone to incorrect connection damage. Equivalent Series Resistance: ESR is an important characteristic to consider when selecting a capacitor. ESR is a resistance internal to a capacitor that is caused by the leads, internal connections, size or area, material composition, and ambient temperature. Capacitor ESR is typically measured in milliohms for ceramic capacitors and can range to more than several ohms for tantalum or aluminum electrolytic capacitors. Ceramic Capacitor Materials: Ceramic capacitors less than 0.1μF are typically made from NPO or C0G materials. NPO and C0G materials typically have tight tolerance and are stable over temperature. Large capacitor values are typically composed of X7R, X5R, Z5U, or Y5V dielectric materials. Large ceramic capacitors, typically greater than 2.2μF, are often available in low-cost Y5V and Z5U dielectrics, but large capacitors are not required in AAT3112 applications. Capacitor area is another contributor to ESR. Capacitors that are physically large will have a lower ESR when compared to an equivalent material smaller capacitor. These larger devices can improve circuit transient response when compared to an equal value capacitor in a smaller package size. η= POUT PIN In addition, with an ideal voltage doubling charge pump, the output current may be expressed as half the input current. The expression to define the ideal efficiency (η) can be rewritten as: η= POUT VOUT × IOUT VOUT = = PIN VIN × 2IOUT 2VIN -orη(%) = 100 ⎛ VOUT ⎞ ⎝ 2VIN ⎠ For a charge pump with an output of 4.5 volts and a nominal input of 2.8 volts, the theoretical efficiency is 80.4%. Due to internal switching losses and IC quiescent current consumption, the actual efficiency can be measured at 79.6%. These figures are in close agreement across a wide range of output load conditions. Efficiency will decrease as load current drops below 0.05mA or when the level of VIN approaches VOUT. Capacitor Selection Careful selection of the four external capacitors CIN, C1, C2, and COUT is important because they will affect turn-on time, output ripple, and transient performance. Optimum performance will be obtained when low equivalent series resistance (ESR) ceramic capacitors are used. In general, low ESR may be defined as less than 100mΩ. Layout Considerations High charge pump switching frequencies and large peak transient currents mandate careful printed circuit board layout. As a general rule for charge pump boost converters, all external capacitors should be located as closely as possible to the device package with minimum length trace connections. Maximize the ground plane around the AAT3112 charge pump and make sure all external capacitors are connected to the immediate ground plane. A local component side ground plane is recommended. 3112.2007.01.1.5 13 500mA High Efficiency Charge Pump for White LED Flash Applications Application Circuits C1 = 1μF C2 = 1μF AAT3112 C1+ C1 - C2 + VIN CIN=10μF VIN C2 VOUT COUT=10μF VOUT EN1 EN2 D1 GND D2 D3 D4 Flash LED R2=10 Q1 TPULSE 100ms - 500ms Figure 1: Flash Application. C1 = 1μF C2 = 1μF C1+ C1 V IN CIN=10μF Light/Movie Mode Enable VIN C2 + C2 VOUT COUT=10μF VOUT EN1 EN2 D1 GND R3=60 - 100 R2=10 LL4148 R1 D2 D3 D4 Flash LED Q1 C3 0.1μF TPULSE Flash Enable 2K Figure 2: Movie Mode Light with Flash Function. 14 3112.2007.01.1.5 500mA High Efficiency Charge Pump for White LED Flash Applications Ordering Information Package QFN33-16 QFN33-16 AAT3112 Marking1 LGXYY MNXYY Part Number (Tape and Reel)2 AAT3112IVN-4.5-T1 AAT3112IVN-5.0-T1 All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means semiconductor products that are in compliance with current RoHS standards, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more information, please visit our website at http://www.analogictech.com/pbfree. Package Information3 QFN33-16 Pin 1 Identification 1 0.230 ± 0.050 5 3.000 ± 0.050 C0.3 0.400 ± 0.100 Pin 1 Dot By Marking 13 9 3.000 ± 0.050 0.500 ± 0.050 Top View Bottom View 1.70 ± 0.05 0.214 ± 0.036 0.025 ± 0.025 Side View All dimensions in millimeters. 1. XYY = assembly and date code. 2. Sample stock is held on part numbers listed in BOLD. 3. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection. 3112.2007.01.1.5 0.900 ± 0.100 15 500mA High Efficiency Charge Pump for White LED Flash Applications AAT3112 © Advanced Analogic Technologies, Inc. AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights, or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice. Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. AnalogicTech warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with AnalogicTech’s standard warranty. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders. Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 Phone (408) 737-4600 Fax (408) 737-4611 16 3112.2007.01.1.5