AAT3112 500mA High Efficiency Charge Pump for White LED Flash Applications General Description Features 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 16-pin 3x3mm QFN package and is rated over the -40°C to +85°C temperature range. 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 <1µA in Shutdown Regulated 4.5V or 5.0V Output 26µA of Quiescent Current Small Application Circuit Automatic Soft Start No Inductors Short-Circuit/Over-Temperature Protection 16-Pin 3x3mm QFN Package Temperature Range: -40°C to +85°C Applications • • • General-Purpose High-Current Boost Supply White LED Backlighting White LED Photo Flash Typical Application VIN C1 = 1µF C2 = 1µF C1+ C2 + C1- VIN C2 VOUT1 CIN C OUT VOUT2 AAT3112 D1 Enable Light EN1 Enable Flash EN2 GND 3112.2004.12.1.2 D2 D3 D4 RB 1 AAT3112 500mA High Efficiency Charge Pump for White LED Flash Applications Pin Descriptions Pin # Symbol 1 2 3 4 5 6 7 N/C C2+ C2N/C VIN GND EN2 8 9 N/C EN1 10 11 12 GND VIN VOUT1 13 14 15 16 N/C C1+ C1VOUT2 EP Function No connect. Flying capacitor 2 positive terminal. Connect 1µF capacitor between C2+ and C2-. Flying capacitor 2 negative terminal. No connect. Input voltage. Connect to Pin 11. Ground connection. Enable pin. When connected high, Charge Pump 2 is enabled. When connected low, it disables the charge pump. No connect. Enable pin. When connected high, Charge Pump 1 is enabled. When connected low, it disables the charge pump. Ground connection. Input voltage. Connect to Pin 5. Output pin for regulated output voltage. Bypass this pin to ground with a low ESR 10µF capacitor. No connect. Flying capacitor 1 positive terminal. Connect 1µF capacitor between C1+ and C1-. Flying capacitor 1 negative terminal. Regulated output voltage 2. Must be connected to VOUT1 for higher current applications. If used separately, bypass this pin to ground with a low ESR 10µF capacitor. Exposed paddle (bottom); connect to GND directly beneath package. Pin Configuration QFN33-16 (Top View) N/C C1+ C1VOUT2 13 14 15 16 N/C C2+ C2N/C 1 12 2 11 3 10 4 9 VOUT1 VIN GND EN1 8 7 6 5 N/C EN2 GND VIN 2 3112.2004.12.1.2 AAT3112 500mA High Efficiency Charge Pump for White LED Flash Applications Absolute Maximum Ratings1 Symbol VIN VOUT VEN TJ TLEAD Description Input Voltage Charge Pump Output EN to GND Voltage Operating Junction Temperature Range Maximum Soldering Temperature (at leads, 10 sec) Value Units -0.3 to 6 -0.3 to 6 -0.3 to 6 -40 to 150 300 V V V °C °C Note 1: Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time. Thermal Information Symbol PD θJA Description Maximum Power Dissipation Maximum Thermal Resistance1 Value Units 2.0 50 W °C/W Note 1: Mounted on an FR4 board. 3112.2004.12.1.2 3 AAT3112 500mA High Efficiency Charge Pump for White LED Flash Applications Electrical Characteristics VIN = 3.3V, VOUT = 5.0V, CIN = COUT = 10 µF, C1 = C2 = 1.0µF; TA = -40°C to 85°C, unless otherwise noted. Typical values are TA = 25°C. Symbol Description AAT3112-4.5 Input Power Supply VIN Operation Range IQ Quiescent Current ISHDN Shutdown Current Conditions Pulsed Output Current VOUT Output Voltage Charge Pump Section FCLK Clock Frequency ηCP Charge Pump Efficiency EN VEN(L) Enable Threshold Low VEN(H) Enable Threshold High IEN EN Input Leakage AAT3112-5.0 Input Power Supply VIN Operation Range IQ Quiescent Current 2 ISHDN Shutdown Current Pulsed Output Current IOUT Charge Pump FCLK ηCP EN VEN(L) VEN(H) IEN Typ Max Units 2.7 2 IOUT VOUT Min Output Voltage Section Clock Frequency Charge Pump Efficiency Enable Threshold Low Enable Threshold High EN Input Leakage 2.7 ≤ VIN ≤ 4.5, IOUT = 0 mA; EN1 = EN2 = VIN EN1 = EN2 = 0 VIN = 3.6V; VOUT = 4.0V; TPULSE = 50mS VIN = 3.6V; VOUT =4.0V; TPULSE = 500mS 2.7 ≤ VIN ≤ 4.5, IOUT = 100mA 3.0 ≤ VIN ≤ 4.5, IOUT = 200mA 26 4.32 4.32 590 500 4.5 4.5 4.5 60 1.0 mA 4.68 4.68 750 80 VIN = 2.7V; IOUT = 100mA 2.7 2.7 ≤ VIN ≤ 5.0, IOUT = 0 mA; EN1 = EN2 = VIN EN1 = EN2 = 0 VIN = 3.6V; VOUT = 4.5V; TPULSE = 50mS VIN = 3.6V; VOUT =4.5V; TPULSE = 500mS 2.7 ≤ VIN ≤ 5.0, IOUT = 100mA 3.0 ≤ VIN ≤ 5.0, IOUT = 200mA 26 4.8 4.8 600 500 5.0 5.0 1.0 V V µA 5.0 60 1.0 V µA µA mA 5.2 5.2 750 85 VIN = 2.7V; IOUT = 100mA V KHz % 0.3 1.4 -1.0 V KHz % 0.3 1.4 -1.0 V µA µA 1.0 V V µA Notes: 1. The AAT3112 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correlation with statistical process controls. 2. VOUT1 and VOUT2 are pulled high to prevent switching. 4 3112.2004.12.1.2 AAT3112 500mA High Efficiency Charge Pump for White LED Flash Applications Typical Characteristics VIN=3.5V, CIN=COUT=10µF, C1=C2=1µF, TA=25°C, unless otherwise noted. VIN vs. VIL VIN vs. VIH 1.00 1.00 0.90 0.95 -40°C 0.85 VIH (V) 0.90 -40°C 0.85 25°C 0.80 0.80 VIL (V) 0.95 0.75 0.70 85°C 0.65 25°C 0.75 0.70 0.65 0.60 85°C 0.60 0.55 0.55 0.50 0.50 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Input Voltage (V) 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Input Voltage (V) VSHDN Threshold vs. Supply Voltage 1.00 VSHDN Threshold (V) 0.95 0.90 VIH 0.85 0.80 0.75 0.70 VIL 0.65 0.60 0.55 0.50 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Input Voltage (V) 3112.2004.12.1.2 5 AAT3112 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. Supply Current vs. Supply Voltage Output Voltage vs. Output Current (No Load, No Switching) 30 5.0 4.8 VIN = 3.6V Supply Current (µ µA) Output Voltage (V) 4.9 VIN = 3.9V 4.7 4.6 4.5 VIN = 4.2V 4.4 4.3 4.2 25 20 15 10 5 4.1 0 4.0 0 50 100 150 200 250 2.5 300 3.0 3.5 Startup Time with 100mA Load Startup Time with 200mA Load EN (2V/div) EN (2V/div) VOUT (1V/div) VOUT (1V/div) 50µ µs/div 50µ µs/div Maximum Current Pulse (50ms pulse) vs. Input Voltage, VOUT > 4.0V Efficiency vs. Supply Voltage 85 800 80 Efficiency (%) Maximum Current Pulse (mA) 4.5 Supply Voltage (V) Output Current (mA) 700 600 500 50mA 75 70 65 200mA 60 100mA 55 50 400 45 300 3 3.2 3.4 3.6 Input Voltage (V) 6 4.0 3.8 4 4.2 40 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 Input Voltage (V) 3112.2004.12.1.2 AAT3112 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. Load Transient Response Load Transient Response (VIN = 3.0V) (VIN = 4.2V) IOUT (200mA/div) IOUT (200mA/div) VOUT (20mV/div) VOUT (20mV/div) 50µs/div 50µs/div Input and Output Ripples Input and Output Ripples (IOUT = 50mA @ VIN = 3.5V) (IOUT = 100mA @ VIN = 3.5V) VIN AC Coupled (20mV/div) VIN AC Coupled (20mV/div) VOUT AC Coupled (20mV/div) VOUT AC Coupled (20mV/div) 5µs/div 5µs/div Output Current vs. Input Voltage Output Current vs. Input Voltage (70°C) (500ms Pulse Time; VOUT > 4.0V) (VOUT > 4.0V) 800 Output Current (mA) Output Current (mA) 800 700 600 500 400 300 200 100 0 50ms 100ms 700 600 200ms 300ms 500 500ms 400 300 200 100 0 2.5 3 3.5 Input Voltage (V) 3112.2004.12.1.2 4 4.5 2.5 3.0 3.5 4.0 4.5 Input Voltage (V) 7 AAT3112 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 50ms Pulse Output Voltage (V) 4.5 4 3.5 500ms Pulse 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 3112.2004.12.1.2 AAT3112 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. Output Voltage vs. Output Current Supply Current vs. Supply Voltage (No Load, No Switching) 30 Output Voltage (V) 5.4 5.3 5.2 VIN = 4.2V 5.1 VIN = 3.9V 5.0 4.9 VIN = 3.6V 4.8 4.7 Supply Current (µ µA) 5.5 25 20 15 10 5 4.6 0 4.5 0 50 100 150 200 250 2.5 300 3.0 3.5 Output Current (mA) 4.5 5.0 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) 50µ µs/div 50µ µs/div Efficiency vs. Supply Voltage Maximum Current Pulse (50ms pulse) vs. Input Voltage, VOUT > 4.5V 95 100mA 90 1000 Efficiency (%) Maximum Current Pulse (mA) 4.0 900 800 700 600 85 80 75 70 200mA 65 50mA 60 55 500 50 400 300 3.0 45 40 3.2 3.4 3.6 Input Voltage (V) 3112.2004.12.1.2 3.8 4.0 4.2 2.7 3.0 3.3 3.5 3.8 4.1 4.4 4.7 4.9 Input Voltage (V) 9 AAT3112 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. Load Transient Response Load Transient Response (VIN = 3.0V) (VIN = 4.2V) IOUT (200mA/div) IOUT (200mA/div) VOUT (20mV/div) VOUT (20mV/div) 50µs/div 50µs/div Input and Output Ripples Input and Output Ripples (IOUT = 50mA @ VIN = 3.5V) (IOUT = 100mA @ VIN = 3.5V) VIN AC Coupled (20mV/div) VIN AC Coupled (20mV/div) VOUT AC Coupled (20mV/div) VOUT AC Coupled (20mV/div) 5µs/div 5µs/div Output Current vs. Input Voltage Output Current vs. Input Voltage (70°C) (500ms Pulse Time; VOUT > 4.5V) (VOUT > 4.5V) 1000 800 50ms Output Current (mA) Output Current (mA) 900 800 700 600 500 400 300 200 100 0 600 500 200ms 300ms 400 500ms 300 200 100 0 3.0 3.5 4.0 Input Voltage (V) 10 100ms 700 4.5 5.0 2.5 3.0 3.5 4.0 4.5 Input Voltage (V) 3112.2004.12.1.2 AAT3112 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. Output Voltage vs. Input Voltage for Pulsed High Current, IOUT = 500mA Output Voltage (V) 6 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) 3112.2004.12.1.2 11 AAT3112 500mA High Efficiency Charge Pump for White LED Flash Applications Functional Block Diagram V IN S2 S1 C1 + EN1 Control Circuit C1 S4 S3 VOUT1 EN2 Control Circuit GND S1 S2 S3 S4 C2+ C2V OUT2 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. 12 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. 3112.2004.12.1.2 AAT3112 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: 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. 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 COG materials. NPO and COG 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. 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. 3112.2004.12.1.2 13 AAT3112 500mA High Efficiency Charge Pump for White LED Flash Applications Application Circuits C1 = 1µF C2 = 1µF C1+ C1 - C2 + VIN VIN C2 VOUT CIN=10µF COUT=10µF VOUT EN1 EN2 D1 D2 D3 D4 Flash LED GND R2=10 Q1 TPULSE 100ms - 500ms Figure 1: Flash Application. C1 = 1µF C2 = 1µF C1+ C1 V IN C2 + VIN C2 VOUT CIN=10µF COUT=10µF VOUT Light/Movie Mode Enable EN1 EN2 D1 D2 D3 D4 Flash LED GND R3=60 - 100 R2=10 LL4148 R1 TPULSE Flash Enable 2K Q1 C3 0.1µF Figure 2: Movie Mode Light with Flash Function. 14 3112.2004.12.1.2 AAT3112 500mA High Efficiency Charge Pump for White LED Flash Applications Ordering Information Package Marking1 Part Number (Tape and Reel) QFN33-16 LGXYY AAT3112IVN-4.5-T1 QFN33-16 MNXYY AAT3112IVN-5.0-T1 Note 1: XYY = assembly and date code. Sample stock is held on part numbers listed in bold. Package Information 0.240 ± 0.060 Pin 1 Identification 1 0.975 ± 0.725 Top View 13 9 0.500 ± 0.050 0.025 ± 0.025 Bottom View 0.213 ± 0.036 0.850 ± 0.150 3.000 ± 0.050 0.400 ± 0.100 Pin 1 Dot By Marking 3.000 ± 0.050 5 Side View All dimensions in millimeters. 3112.2004.12.1.2 15 AAT3112 500mA High Efficiency Charge Pump for White LED Flash Applications 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, and advise customers 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. Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 Phone (408) 737-4600 Fax (408) 737-4611 16 3112.2004.12.1.2