AAT3110 AAT | Alldatasheet

Document overview

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Technical content

Features

  • Step-Up Voltage Converter
  • Input Voltage Range: — AAT3110-5: 2.7V to 5V — AAT3110-4.5: 2.7V to 4.5V
  • MicroPower Consumption: 13µA
  • Regulated 5V, 4.5V ±4% Output
  • 5V Output Current: — 100mA with V IN ≥ 3.0V — 50mA with V IN ≥ 2.7V
  • 4.5V Output Current: — 100mA with V IN ≥ 3.0V — 50mA with V IN ≥ 2.7V
  • Peak Current 250mA for 100ms
  • High Frequency 750kHz Operation
  • Shutdown Mode Draws Less Than 1µA
  • Short-Circuit/Over-Temperature Protection
  • 2kV ESD Rating
  • SC70JW-8 or SOT23-6 Package

Applications

  • Cellular Phones
  • Digital Cameras
  • Handheld Electronics
  • LED/Display Backlight Driver
  • LEDs for Camera Flash
  • PDAs
  • Portable Communication Devices Typical Application VIN VOUT GND SHDN VIN AAT3110 VOUT 1µF 10µF 10µF ON/OFF COUT CIN

Pin # SOT23-6 SC70JW-8 Symbol Function 1 1 VOUT Regulated output pin. Bypass this pin to ground with a 6.8µF (min) low equivalent series resistance (ESR) capacitor. 2 2, 3, 4 GND Ground connection. 3 5 SHDN Shutdown input. Logic low signal disables the converter. 4 6 C- Flying capacitor negative terminal. 5 7 VIN Input supply pin. Bypass this pin to ground with a 6.8µF (min) low-ESR capacitor. 6 8 C+ Flying capacitor positive terminal. AAT3110 MicroPower™ Regulated Charge Pump 2 3110.2005.11.1.4

TA = 25°C, unless otherwise noted. Thermal Information3 Symbol Description Rating Units ΘJA Maximum Thermal Resistance 150 °C/W PD Maximum Power Dissipation 667 mW Symbol Description Value Units VIN VIN to GND -0.3 to 6 V VOUT VOUT to GND -0.3 to 6 V VSHDN SHDN to GND -0.3 to 6 V tSC Output to GND Short-Circuit Duration Indefinite s TJ Operating Junction Temperature Range -40 to 150 °C TLEAD Maximum Soldering Temperature (at leads, 10 sec) 300 °C VESD ESD Rating2 — HBM 2000 V AAT3110 MicroPower™ Regulated Charge Pump 3110.2005.11.1.4 3 1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at condi- tions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time. 2. Human body model is a 100pF capacitor discharged through a 1.5k Ω resistor into each pin. 3. Mounted on an FR4 board.

MicroPower™ Regulated Charge Pump 4 3110.2005.11.1.4

Electrical Characteristics

TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C, CFLY = 1µF, CIN = 10µF, COUT = 10µF. Symbol Description Conditions Min Typ Max Units AAT3110-5 VIN Input Voltage V OUT = 5.0V 2.7 V OUT V IQ No Load Supply Current1 2.7V < VIN < 5V, IOUT = 0mA, SHDN = VIN 13 30 µA VRIPPLE Ripple Voltage VIN = 2.7V, IOUT = 50mA 25 mVP-PVIN = 3V, IOUT = 100mA 30 η Efficiency V IN = 2.7V, IOUT = 50mA 92 % fOSC Frequency Oscillator Free Running 750 kHz VIH SHDN Input Threshold High 1.4 V VIL SHDN Input Threshold Low 0.3 V IIH SHDN Input Current High SHDN = V IN -1 1 µA IIL SHDN Input Current Low SHDN = GND -1 1 µA tON VOUT Turn-On Time V IN = 3V, IOUT = 0mA 0.2 ms ISC Short-Circuit Current2 VIN = 3V, VOUT = GND, SHDN = 3V 300 mA AAT3110-4.5 VIN Input Voltage V OUT = 4.5V 2.7 V OUT V IQ No Load Supply Current3 2.7V < VIN < 4.5V, IOUT = 0mA, SHDN = VIN 13 30 µA VRIPPLE Ripple Voltage VIN = 2.7V, IOUT = 50mA 25 mVP-PVIN = 3V, IOUT = 100mA 30 η Efficiency V IN = 2.7V, IOUT = 50mA 83 % fOSC Frequency Oscillator Free Running 750 kHz VIH SHDN Input Threshold High 1.4 V VIL SHDN Input Threshold Low 0.3 V IIH SHDN Input Current High SHDN = V IN -1 1 µA IIL SHDN Input Current Low SHDN = GND -1 1 µA tON VOUT Turn-On Time V IN = 3V, IOUT = 0mA 0.2 ms ISC Short-Circuit Current2 VIN = 3V, VOUT = GND, SHDN = 3V 300 mA 1. VOUT is pulled up to 5.5V to prevent switching. 2. Under short-circuit conditions, the device may enter over-temperature protection mode. 3. VOUT is pulled up to 5.0V to prevent switching.

Typical Characteristics—AAT3110-5V Unless otherwise noted, VIN = 3V, CIN = COUT = 10µF, CFLY = 1µF, TA = 25°C. Oscillator Frequency vs. Supply Voltage 400 500 600 700 800 900 1000 1100 1200 Supply Voltage (V) Oscillator Frequency (kHz) - 40°C 85°C 25°C 0.01 0.1 1 10 100 1000 100 Efficiency vs. Load Current Load Current (mA) Efficiency (%) VIN = 3.6V VIN = 3.3V VIN = 3.0V VIN = 2.7V Efficiency vs. Supply Voltage Supply Voltage (V) Efficiency (%) 50mA 100mA 25mA Supply Current vs. VSHDN 01 2345 VSHDN Control Voltage (V) Supply Current (µA) VIN = 5.5V VIN = 3.3VVIN = 2.8V IOUT = 0µA Supply Current (µA) Supply Current vs. Supply Voltage 2.5 3 3.5 4 4.5 5 5.5 Supply Voltage (V) IOUT = 0µA CFLY = 1µF VSHDN = VIN Output Voltage vs. Output Current 4.8 4.85 4.9 4.95 5.05 5.1 5.15 0 50 100 150 Output Current (mA) Output Voltage (V) VIN = 2.7V VIN = 3.0V VIN = 3.3V VIN = 3.6V AAT3110 MicroPower™ Regulated Charge Pump 3110.2005.11.1.4 5

MicroPower™ Regulated Charge Pump 6 3110.2005.11.1.4 Typical Characteristics—AAT3110-5V Unless otherwise noted, VIN = 3V, CIN = COUT = 10µF, CFLY = 1µF, TA = 25°C. Output Ripple with IOUT = 100mA Time (2µs/div) VOUT AC Coupled (10 mV/div) VIN = 3.0V Output Ripple with IOUT = 50mA Time (2µs/div) VOUT AC Coupled (10 mV/div) VIN = 3.0V Load Transient Response for 100mA Time (50µs/div) IOUT 0mA to 100 mA (50mA/div) VOUT AC Coupled (20mV/div) VIN = 3.0V Load Transient Response for 50mA Time (50µs/div) IOUT 0mA to 50mA (20mA/div) VOUT AC Coupled (20mV/div) VIN = 3.0V Startup Time with 100mA Load Time (50µs/div) SHDN (2V/div) (1V/div) VOUT Startup Time with 50mA Load Time (50µs/div) SHDN (2V/div) VOUT (1V/div)

MicroPower™ Regulated Charge Pump 3110.2005.11.1.4 7 Typical Characteristics—AAT3110-5V Unless otherwise noted, VIN = 3V, CIN = COUT = 10µF, CFLY = 1µF, TA = 25°C. Output Voltage vs. Input Voltage (IOUT = 250mA) 3.2 3.6 4.4 4.8 5.2 Input Voltage (V) Output Voltage (V) one shot pulse t = 100ms -20°C 55°C 20°C

MicroPower™ Regulated Charge Pump 8 3110.2005.11.1.4 Typical Characteristics—AAT3110-4.5V Unless otherwise noted, VIN = 3V, CIN = COUT = 10µF, CFLY = 1µF, TA = 25°C. Oscillator Frequency vs. Supply Voltage 400 500 600 700 800 900 1000 1100 1200 Supply Voltage (V) Oscillator Frequency (kHz) - 40°C 85°C 25°C Efficiency vs. Load Current 0.1 1 10 100 1000 Load Current (mA) Efficiency (%) VIN = 2.7V VIN = 3.0V VIN = 3.3V Efficiency vs. Supply Voltage Supply Voltage (V) Efficiency (%) 100mA 50mA 5mA Supply Current vs. VSHDN 01 2345 VSHDN Control Voltage (V) Supply Current (µA) VIN = 5.5V VIN = 3.3VVIN = 2.8V IOUT = 0µA Supply Current vs. Supply Voltage 2.5 3 3.5 4 4.5 Supply Voltage (V) Supply Current (µA) No Load, Switching No Load, No Switching Output Voltage vs. Output Current 4.49 4.5 4.51 4.52 4.53 4.54 0.1 1 10 100 1000 Output Current (mA) Output Voltage (V) 2.7V 3.0V 3.3V 3.6V

MicroPower™ Regulated Charge Pump 3110.2005.11.1.4 9 Typical Characteristics—AAT3110-4.5V Unless otherwise noted, VIN = 3V, CIN = COUT = 10µF, CFLY = 1µF, TA = 25°C. Maximum Current Pulse vs. Input Voltage 100 200 300 400 500 600 Input Voltage (V) Maximum Current Pulse (mA) One-shot pulse duration = 50ms VOUT > 4.0V Output Voltage vs. Input Voltage for Pulsed High Current 4.1 4.2 4.3 4.4 4.5 4.6 Input Voltage (V) Output Voltage (V) One-shot pulse duration = 50ms IOUT = 250mA Output Ripple (IOUT = 100mA @ VIN = 3.0V) Time (5µs/div) VOUT AC Coupled (5mV/div) Output Ripple (IOUT = 50mA @ VIN = 2.7V) Time (5µs/div) VOUT AC Coupled (5mV/div) Load Transient Response (VIN = 3.0V) Time (50µs/div) IOUT (100mA/div) VOUT (20mV/div) Load Transient Response (VIN = 2.7V) Time (50µs/div) IOUT (100mA/div) VOUT (20mV/div)

Typical Characteristics—AAT3110-4.5V Unless otherwise noted, VIN = 3V, CIN = COUT = 10µF, CFLY = 1µF, TA = 25°C. Startup Time (100µs/div) VOUT (2V/div) SHDN (1V/div) ILOAD = 50mA @ VIN = 2.7V ILOAD = 100mA @ VIN = 3.0V ILOAD = 150mA @ VIN = 3.3V AAT3110 MicroPower™ Regulated Charge Pump 10 3110.2005.11.1.4

MicroPower™ Regulated Charge Pump 3110.2005.11.1.4 11 Typical Characteristics—AAT3110 Unless otherwise noted, VIN = 3V, CIN = COUT = 10µF, CFLY = 1µF, TA = 25°C. Normalized Output Voltage vs. Temperature -0.60 -0.40 -0.20 0.00 0.20 0.40 0.60 0.80 1.00 1.20 -50 -25 0 25 50 75 100 125 Temperature (°C) Normalized Output Voltage (%) IOUT = 25mA VSHDN Threshold vs. Input Voltage 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 Input Voltage (V) VSHDN Threshold (V) VIH VIL SHDN Input Threshold (low) vs. Input Voltage 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 Input Voltage (V) SHDN Input Threshold (low) (V) -40°C 85°C 25°C SHDN Input Threshold (high) vs. Input Voltage 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 Input Voltage (V) SHDN Input Threshold (high) (V) 85°C 25°C -40°C

MicroPower™ Regulated Charge Pump 12 3110.2005.11.1.4 Functional Description Operation (Refer to block diagram) The AAT3110 uses a switched capacitor charge pump to boost an input voltage to a regulated output voltage. Regulation is achieved by sensing the charge pump output voltage through an internal resistor divider network. A switched doubling circuit is enabled when the divided output drops below a preset trip point controlled by an internal comparator. The charge pump switch cycling enables four inter- nal switches at two non-overlapping phases. During the first phase, switches S1 and S4 are switched on (short) and switches S2 and S3 are off (open). The flying capacitor C FLY is charged to a level approxi- mately equal to input voltage VIN. During the second phase, switches S1 and S4 are turned off (open) and switches S2 and S3 are turned on (short). The low side of the flying capacitor C FLY is connected to GND during the first phase. During the second phase, the flying capacitor C FLY is switched so that the low side is connected to VIN. The voltage at the high side of the flying capacitor CFLY is bootstrapped to 2 × VIN and is connected to output through a switch. For each cycle phase, charge from input node V IN is transported from a lower voltage to a higher voltage. This cycle repeats itself until the output node voltage is high enough to exceed the preset input threshold of the control comparator. When the output voltage exceeds the internal trip point level, the switching cycle stops and the charge pump circuit is tem- porarily placed in an idle state. When idle, the AAT3110 has a quiescent current of 13µA or less. The closed loop feedback system containing the voltage sense circuit and control comparator allows the AAT3110 to provide a regulated output voltage to the limits of the input voltage and output load cur- rent. The switching signal, which drives the charge pump, is created by an integrated oscillator within the control circuit block. The free-running charge pump switching frequency is approximately 750kHz. The switching frequency under an active load is a function of V IN, VOUT, COUT ,and IOUT. For each phase of the switching cycle, the charge transported from VIN to VOUT can be approximated by the following formula: VPHASE ≈ CFLY × (2 × VIN - VOUT) The relative average current that the charge pump can supply to the output may be approximated by the following expression: I OUT(AVG) α CFLY × (2 × VIN - VOUT) × FSW The AAT3110 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. The charge pump will remain disabled until the fault condition is relieved. Functional Block Diagram VREF CONTROL SHDN VIN VOUT GND

MicroPower™ Regulated Charge Pump 3110.2005.11.1.4 13 Applications Information External Capacitor Selection Careful selection of the three external capacitors CIN, COUT, and CFLY is very important because they will affect turn-on time, output ripple, and transient performance. Optimum performance will be obtained when low ESR ceramic capacitors are used. In general, low ESR may be defined as less than 100mΩ. If desired for a particular application, low ESR tantalum capacitors may be substituted; however, optimum output ripple performance may not be realized. Aluminum electrolytic capacitors are not recommended for use with the AAT3110 due to their inherent high ESR characteristic. Typically as a starting point, a capacitor value of 10µF should be used for C IN and COUT with 1µF for CFLY when the AAT3110 is used under maximum output load conditions. Lower values for CIN, COUT, and CFLY may be utilized for light load current appli- cations. Applications drawing a load current of 10mA or less may use a C IN and C OUT capacitor value as low as 1µF and a CFLY value of 0.1µF. CIN and C OUT may range from 1µF for light loads to 10µF or more for heavy output load conditions. C FLY may range from 0.01µF to 2.2µF or more. If CFLY is increased, C OUT should also be increased by the same ratio to minimize output ripple. As a basic rule, the ratio between C IN, COUT, and C FLY should be approximately 10 to 1. The compromise for lowering the value of C IN, COUT, and the flying capacitor CFLY is that the output ripple voltage may be increased. In any case, if the external capacitor values deviate greatly from the recommendation of C IN = COUT = 10µF and C FLY = 1µF, the AAT3110 output performance should be evaluated to assure the device meets application requirements. In applications where the input voltage source has very low impedance, it is possible to omit the C IN capacitor. However, if C IN is not used, circuit per- formance should be evaluated to assure desired operation is achieved. Under high peak current operating conditions that are typically experienced during circuit start-up or when load demands create a large inrush current, poor output voltage regula- tion can result if the input supply source impedance is high or if the value of C IN is too low. This situation can be remedied by increasing the value of CIN. Capacitor Characteristics Ceramic composition capacitors are highly recom- mended over all other types of capacitors for use with the AAT3110. Ceramic capacitors offer many advan- tages over their tantalum and aluminum electrolytic counterparts. A ceramic capacitor typically has very low ESR, is lower cost, has a smaller PCB footprint, and is non-polarized. Low ESR ceramic capacitors help maximize charge pump transient response. Since ceramic capacitors are non-polarized, they are not prone to incorrect connection damage. Equivalent Series Resistance: ESR is a very important characteristic to consider when selecting a capacitor. ESR is a resistance internal to a capacitor that is caused by the leads, internal con- nections, size or area, material composition, and ambient temperature. Typically, capacitor ESR is measured in milliohms for ceramic capacitors and can range to more then 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 very stable over tem- perature. Large capacitor values are typically com- posed of X7R, X5R, Z5U, or Y5V dielectric materi- als. Large ceramic capacitors, typically greater than 2.2µF, are often available in low-cost Y5V and Z5U dielectrics. If these types of capacitors are select- ed for use with the charge pump, the nominal value should be doubled to compensate for the capacitor tolerance which can vary more than ±50% over the operating temperature range of the device. A 10µF Y5V capacitor could be reduced to less than 5µF over temperature; this could cause problems for cir- cuit operation. X7R and X5R dielectrics are much more desirable. The temperature tolerance of X7R dielectric is better than ±15%. 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. Charge Pump Efficiency The AAT3110 is a regulated output voltage dou- bling charge pump. The efficiency ( η) can simply

MicroPower™ Regulated Charge Pump 14 3110.2005.11.1.4 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. 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: -or- For a charge pump with an output of 5.0V and a nominal input of 3.0V, the theoretical efficiency is 83.3%. Due to internal switching losses and IC quiescent current consumption, the actual efficien- cy can be measured at 82.7%. These figures are in close agreement for output load conditions from 1mA to 100mA. Efficiency will decrease as load current drops below 0.05mA or when the level of V IN approaches VOUT. Refer to the Typical Char- acteristics section of this datasheet for measured plots of efficiency versus input voltage and output load current for the given charge pump output volt- age options. Short-Circuit and Thermal Protection In the event of a short-circuit condition, the charge pump can draw a much as 100mA to 400mA of cur- rent from V IN. This excessive current consumption due to an output short-circuit condition will cause a rise in the internal IC junction temperature. The AAT3110 has a thermal protection and shutdown circuit that continuously monitors the IC junction temperature. If the thermal protection circuit sens- es the die temperature exceeding approximately 145°C, the thermal shutdown will disable the charge pump switching cycle operation. The ther- mal limit system has 10°C of system hysteresis before the charge pump can reset. Once the over- current event is removed from the output and the junction temperature drops below 135°C, the charge pump will become active again. The ther- mal protection system will cycle on and off if an out- put short-circuit condition persists. This will allow the AAT3110 to operate indefinitely under short-cir- cuit conditions without damaging the device. Output Ripple and Ripple Reduction There are several factors that determine the ampli- tude and frequency of the charge pump output rip- ple, the values of C OUT and CFLY, the load current IOUT, and the level of VIN. Ripple observed at VOUT is typically a sawtooth waveform in shape. The rip- ple frequency will vary depending on the load current I OUT and the level of VIN. As VIN increases, the abil- ity of the charge pump to transfer charge from the input to the output becomes greater. As it does, the peak-to-peak output ripple voltage will also increase. The size and type of capacitors used for C IN, COUT, and C FLY have an effect on output ripple. Since output ripple is associated with the R/C charge time constant of these two capacitors, the capaci- tor value and ESR will contribute to the resulting charge pump output ripple. This is why low ESR capacitors are recommended for use in charge pump applications. Typically, output ripple is not greater than 30mV P-P when V IN = 3.0V, V OUT = 5.0V, COUT = 10µF, and CFLY = 1µF. When the AAT3110 is used in light output load appli- cations where IOUT < 10mA, the flying capacitor CFLY value can be reduced. The reason for this effect is when the charge pump is under very light load con- ditions, the transfer of charge across C FLY is greater during each phase of the switching cycle. The result is higher ripple seen at the charge pump output. This effect will be reduced by decreasing the value of C FLY. Caution should be observed when decreas- ing the flying capacitor. If the output load current rises above the nominal level for the reduced C FLY value, charge pump efficiency can be compromised. There are several methods that can be employed to reduce output ripple depending upon the require- ments of a given application. The most simple and straightforward technique is to increase the value of η(%) = 100 VOUT 2VIN η = POUT = VOUT × IOUT = VOUT PIN VIN × 2IOUT 2VIN η = POUT PIN

MicroPower™ Regulated Charge Pump 18 3110.2005.11.1.4

Ordering Information

Package Information

All dimensions in millimeters.

1.90 BSC

0.95 BSC

0.45 ± 0.15 0.10 BSC 2.85 ± 0.15 0.075 ± 0.075 0.40 ± 0.10 × 6 1.575 ± 0.125 1.20 ± 0.25 1.10 ± 0.20 2.80 ± 0.20 4° ± 4° 10° ± 5° 0.15 ± 0.07 GAUGE PLANE

0.60 REF

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. Output Voltage Package Marking 1 Part Number (Tape and Reel)2 4.5V SOT23-6 EEXYY AAT3110IGU-4.5-T1 5.0V SOT23-6 ASXYY AAT3110IGU-5.0-T1 4.5V SC70JW-8 EEXYY AAT3110IJS-4.5-T1 5.0V SC70JW-8 ASXYY AAT3110IJS-5.0-T1 1. XYY = assembly and date code. 2. Sample stock is generally held on all part numbers listed in BOLD.

All dimensions in millimeters. 0.225 ± 0.075 0.45 ± 0.10 0.05 ± 0.05 2.10 ± 0.30 2.00 ± 0.20 7° ± 3° 4° ± 4° 0.15 ± 0.05

1.10 MAX

0.100 2.20 ± 0.20 0.048REF 0.50 BSC 0.50 BSC 0.50 BSC AAT3110 MicroPower™ Regulated Charge Pump 3110.2005.11.1.4 19

MicroPower™ Regulated Charge Pump 20 3110.2005.11.1.4 Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 Phone (408) 737-4600 Fax (408) 737-4611 © 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 con- trol 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.