AAT3201
150mA OmniPower™ LDO Linear Regulator General Description
The AAT3201 PowerLinear OmniPower low dropout (LDO) linear regulator is ideal for systems where a low-cost solution is critical. This device features extremely low quiescent current, typically 20µA. Dropout voltage is also very low, typically 200mV. The AAT3201 has an enable pin feature which, when pulled low, will enter the LDO regulator into shutdown mode, removing power from its load and offering extended power conservation capabilities for portable, battery-powered applications. The AAT3201 has output short-circuit and overcurrent protection. In addition, the device has an over-temperature protection circuit that will shut down the LDO regulator during extended over-current events. The AAT3201 is available in the Pb-free, space-saving 5-pin SOT23 package. The device is rated over the -40°C to +85°C temperature range. Since only a small, 1µF ceramic output capacitor is recommended, the AAT3201 is a truly cost-effective voltage conversion solution. The AAT3201 is similar to the AAT3200 with the exception that it offers further power savings with its enable pin.
Features
• • • • • • • • • • •
PowerLinear™
20µA Quiescent Current Low Dropout: 200mV (typical) Guaranteed 150mA Output High Accuracy: ±2% Current Limit Protection Over-Temperature Protection Extremely Low Power Shutdown Mode Low Temperature Coefficient Factory-Programmed Output Voltages — 1.8V to 3.5V Stable Operation With Virtually Any Output Capacitor Type 5-Pin SOT23 Package
Applications
• • Cellular Phones Consumer Electronics
Typical Application
INPUT IN OUT OUTPUT
AAT3201
ENABLE CIN 1µF GND EN GND COUT 1µF GND
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AAT3201
150mA OmniPower™ LDO Linear Regulator Pin Descriptions
Pin #
1 2 3 4 5
Symbol
IN GND EN NC OUT
Function
Input pin. Ground connection pin. Enable pin; when pulled low, the PMOS pass transistor turns off and all internal circuitry enters low-power mode, consuming less than 1µA. Not connected. Output pin; should be decoupled with 1µF or greater capacitor.
Pin Configuration
SOT23-5 (Top View) IN GND EN
1 5
OUT
2
3
4
NC
2
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AAT3201
150mA OmniPower™ LDO Linear Regulator Absolute Maximum Ratings1
TA = 25°C, unless otherwise noted. Symbol
VIN VEN VENIN(MAX) IOUT TJ TLEAD
Description
Input Voltage EN to GND Voltage Maximum EN to Input Voltage Maximum DC Output Current Operating Junction Temperature Range Maximum Soldering Temperature (at leads, 10 sec)
Value
-0.3 to 6 -0.3 to 6 0.3 PD/(VIN-VO) -40 to 150 300
Units
V V V mA °C °C
Thermal Information2
Symbol
ΘJA PD
Description
Thermal Resistance Power Dissipation
Rating
150 667
Units
°C/W mW
Recommended Operating Conditions
Symbol
VIN T
Description
Input Voltage Ambient Temperature Range
Rating
(VOUT+VDO) to 5.5 -40 to +85
Units
V °C
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. 2. Mounted on a demo board. 3201.2006.01.1.2
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AAT3201
150mA OmniPower™ LDO Linear Regulator Electrical Characteristics
VIN = VOUT(NOM) + 1V, IOUT = 1mA, COUT = 1µF; TA = 25°C, unless otherwise noted. Symbol
VOUT IOUT ISC IQ ISD ∆VOUT/VOUT
Description
DC Output Voltage Tolerance Maximum Output Current Short-Circuit Current Ground Current Shutdown Current Line Regulation
Conditions
VOUT > 1.2V VOUT < 0.4V VIN = 5V, No Load EN = Inactive VIN = 4.0V to 5.5V VOUT = VOUT = VOUT = VOUT = VOUT = IL= 1 to 100mA VOUT = VOUT = VOUT = VOUT = VOUT = VOUT = VOUT = VOUT = VOUT = VOUT = VOUT = IOUT = 100mA VOUT = VOUT = VOUT = VOUT = VOUT = VOUT = VIN = 5V VON = 5.5V 100Hz
Min
-2.0 150
Typ
Max
2.0
Units
% mA mA µA µA %/V
350 20 0.15 1.0 0.9 0.8 0.8 0.8 0.7 0.7 0.7 0.6 0.5 0.5 290 265 230 220 210 200 190 190 190 180 180 2.4 0.01 50 140 20 350 80
∆VOUT/VOUT
Load Regulation
VDO
Dropout Voltage1
1.8 2.0 2.3 2.4 2.5 2.7 2.8 2.85 3.0 3.3 3.5 1.8 2.0 2.3 2.4 2.5 2.7 2.8 2.85 3.0 3.3 3.5
VEN(L) VEN(H) IEN(SINK) PSRR TSD THYS eN TC
EN Input Low Voltage EN Input High Voltage EN Input leakage Power Supply Rejection Ratio Over-Temperature Shutdown Threshold Over-Temperature Shutdown Hysteresis Output Noise Output Voltage Temperature Coefficient
30 1 0.6 1.65 1.60 1.45 1.40 1.35 1.25 1.20 1.20 1.15 1.00 1.00 410 385 345 335 335 310 305 300 295 295 290 0.8 1
%
mV
V V µA dB °C °C µVRMS PPM/°C
1. VDO is defined as VIN - VOUT when VOUT is 98% of nominal.
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AAT3201
150mA OmniPower™ LDO Linear Regulator Typical Characteristics
Unless otherwise noted, VIN = VOUT + 1V, TA = 25°C, COUT = 5.6µF ceramic, IOUT = 100mA. Output Voltage vs. Output Current
3.03
3.1
Output Voltage vs. Input Voltage
Output Voltage (V)
Output Voltage (V)
3.02 3.01 3
3 2.9 2.8 2.7
1mA 40mA
-30°C 25°C
2.99 2.98 2.97 0 20 40
80°C
10mA
2.6 2.5
60
80
100
2.7
2.9
3.1
3.3
3.5
Output Current (mA)
Input Voltage (V)
Output Voltage vs. Input Voltage
3.03 40 0
Dropout Voltage vs. Output Current
3.02
1mA 10mA
Dropout Voltage (mV)
Output Voltage (V)
300
80°C
200
3.01
25°C -30°C
40mA
3
100
2.99 3.5 4 4.5 5 5.5
0 0 25 50 75 100 125 150
Input Voltage (V)
Output Current (mA)
PSRR With 10mA Load
60 30
Noise Spectrum
40
Noise (dB µV/rt Hz )
1.E+02 1.E+03 1.E+04 1.E+05
20 10 0 -10 -20 -30 1.E+01
PSRR (dB)
20
0 1.E+01
Frequency (Hz)
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
Freque ncy (Hz)
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AAT3201
150mA OmniPower™ LDO Linear Regulator Typical Characteristics
Unless otherwise noted, VIN = VOUT + 1V, TA = 25°C, COUT = 5.6µF ceramic, IOUT = 100mA. Line Response With 1mA Load
3.8 3.6 6 5 4
Load Transient – 1mA/40mA
320
Output Current (mA)
Output Voltage ( V )
Input
3.4 3.2 3 4 3 2
Output Voltage (V)
Input Voltage ( V )
240
Output
3 160
Output
2.8 2.6 -200 1 0 800
80
2 -1 0 1 2 3
0
0
200
400
600
Time ( µs)
Time (ms)
Line Response With 10mA Load
3.8 6 5 4
Load Transient – 1mA/80mA
320
Output Voltage ( V )
Input
3.4 3.2 3 4 3 2
Output Voltage (V)
3.6
Output Current (mA)
Input Voltage ( V )
240
Output
3 160
Output
2.8 2.6 -200 1 0 800
80
2 -1 0 1 2 3
0
0
200
400
600
Time (µs)
Time (ms)
Line Response With 100mA Load
3.8 3.6 6 5
Input Voltage ( V )
Output Voltage ( V )
Input
3.4 3.2 3 4 3 2
Output
2.8 2.6 -200 1 0 800
0
200
400
600
Time (µs)
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AAT3201
150mA OmniPower™ LDO Linear Regulator Typical Characteristics
Unless otherwise noted, VIN = VOUT + 1V, TA = 25°C, COUT = 5.6µF ceramic, IOUT = 100mA. Power-Up With 1mA Load
4 5 4 4
Turn-On With 1mA Load
3
Output Voltage (V)
Enable Voltage (V)
Output Voltage (V)
Input Voltage (V)
3
3 2
3
2
2
Enable
Enable
2 1
1 0
1
-1
1
0
Output
0 -1 0 1 2
-2 -3 0 -1
Output
-1 0 1 2
Time (ms)
Time (ms)
Power-Up With 10mA Load
4 5 4 4
Turn-On With 10mA Load
3
Enable Voltage (V)
Output Voltage (V)
Output Voltage (V)
3
3 2
3
2
Input Voltage (V)
2
Enable
Enable
2 1
1 0
1
-1
1
0
Output
0 -1 0 1 2
-2 -3 0 -1
Output
-1 0 1 2
Time (ms)
Time (ms)
Power-Up With 100mA Load
4 5 4 4
Turn-On With 100mA Load
3
Enable Voltage (V)
Output Voltage (V)
Output Voltage (V)
Input Voltage (V)
3
3 2
3
2
2
Enable
1 0
2
Enable
1
1
-1
1
0
Output
0 -1 0 1 2
-2 -3 0 -1
Output
-1 0 1 2
Time (ms)
Time (ms)
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AAT3201
150mA OmniPower™ LDO Linear Regulator Functional Block Diagram
IN
Over-Current Protection Over-Temperature Protection
OUT
EN
VREF
GND
Functional Description
The AAT3201 is intended for LDO regulator applications where output current load requirements range from no load to 150mA. The advanced circuit design of the AAT3201 has been optimized for use as the most cost-effective solution. The typical quiescent current level is just 20µA. The AAT3201 also contains an enable circuit, which has been provided to shut down the LDO regulator for additional power conservation in portable products. In the shutdown state, the LDO draws less than 1µA from input supply. The LDO also demonstrates excellent power supply rejection ratio (PSRR), and load and line transient response characteristics.
The LDO regulator output has been specifically optimized to function with low-cost, low-equivalent series resistance (ESR) ceramic capacitors. However, the design will allow for operation with a wide range of capacitor types. The AAT3201 has complete short-circuit and thermal protection. The integral combination of these two internal protection circuits gives the AAT3201 a comprehensive safety system to guard against extreme adverse operating conditions. Device power dissipation is limited to the package type and thermal dissipation properties. Refer to the Thermal Considerations section of this datasheet for details on device operation at maximum output load levels.
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AAT3201
150mA OmniPower™ LDO Linear Regulator Applications Information
To assure the maximum possible performance is obtained from the AAT3201, please refer to the following application recommendations. needed can be calculated from the step size of the change in output load current expected and the voltage excursion that the load can tolerate. The total output capacitance required can be calculated using the following formula: ∆I × 15µF ∆V
Input Capacitor
Typically, a 1µF or larger capacitor is recommended for CIN in most applications. A CIN capacitor is not required for basic LDO regulator operation. However, if the AAT3201 is physically located any distance more than one or two centimeters from the input power source, a CIN capacitor will be needed for stable operation. CIN should be located as closely to the device VIN pin as practically possible. CIN values greater than 1µF will offer superior input line transient response and will assist in maximizing the power supply ripple rejection. Ceramic, tantalum, or aluminum electrolytic capacitors may be selected for CIN as there is no specific capacitor ESR requirement. For 150mA LDO regulator output operation, ceramic capacitors are recommended for CIN due to their inherent capability over tantalum capacitors to withstand input current surges from low impedance sources such as batteries in portable devices. COUT = Where:
∆I = maximum step in output current ∆V = maximum excursion in voltage that the load can tolerate Note that use of this equation results in capacitor values approximately two to four times the typical value needed for an AAT3201 at room temperature. The increased capacitor value is recommended if tight output tolerances must be maintained over extreme operating conditions and maximum operational temperature excursions. If tantalum or aluminum electrolytic capacitors are used, the capacitor value should be increased to compensate for the substantial ESR inherent to these capacitor types.
Capacitor Characteristics Output Capacitor
For proper load voltage regulation and operational stability, a capacitor is required between pins VOUT and GND. The COUT capacitor connection to the LDO regulator ground pin should be made as direct as practically possible for maximum device performance. The AAT3201 has been specifically designed to function with very low ESR ceramic capacitors. Although the device is intended to operate with these low ESR capacitors, it is stable over a very wide range of capacitor ESR, thus it will also work with some higher ESR tantalum or aluminum electrolytic capacitors. However, for best performance, ceramic capacitors are recommended. The value of COUT typically ranges from 0.47µF to 10µF; however, 1µF is sufficient for most operating conditions. If large output current steps are required by an application, then an increased value for COUT should be considered. The amount of capacitance Ceramic composition capacitors are highly recommended over all other types of capacitors for use with the AAT3201. Ceramic capacitors offer many advantages 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. Line and load transient response of the LDO regulator is improved by using low ESR ceramic capacitors. Since ceramic capacitors are non-polarized, they are less prone to damage if incorrectly connected. Equivalent Series Resistance: ESR is an important characteristic to consider when selecting a capacitor. ESR is the internal series resistance associated with a capacitor that includes lead resistance, internal connections, capacitor size and area, material composition, and ambient temperature. Typically capacitor ESR is measured in milliohms for ceramic capacitors and can range to more than several ohms for tantalum or aluminum electrolytic capacitors.
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AAT3201
150mA OmniPower™ LDO Linear Regulator
Ceramic Capacitor Materials: Ceramic capacitors less than 0.1µF are typically made from NPO or C0G materials. NPO and C0G materials generally have tight tolerance and are very stable over temperature. Larger capacitor values are usually composed of X7R, X5R, Z5U, or Y5V dielectric materials. Large ceramic capacitors (i.e., greater than 2.2µF) are often available in low-cost Y5V and Z5U dielectrics. These two material types are not recommended for use with LDO regulators since the capacitor tolerance can vary more than ±50% over the operating temperature range of the device. A 2.2µF Y5V capacitor could be reduced to 1µF over the full operating temperature range. This can cause problems for circuit operation and stability. 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 in size will have a lower ESR when compared to a smaller sized capacitor of equivalent material and capacitance value. These larger devices can also improve circuit transient response when compared to an equal value capacitor in a smaller package size. Consult capacitor vendor datasheets carefully when selecting capacitors for use with LDO regulators. to continually draw more than the current limit threshold, the LDO regulator's output voltage would drop to a level necessary to supply the current demanded by the load. Under short-circuit or other over-current operating conditions, the output voltage would drop and the AAT3201's die temperature would rapidly increase. Once the regulator's power dissipation capacity has been exceeded and the internal die temperature reaches approximately 140°C the system thermal protection circuit will become active. The internal thermal protection circuit will actively turn off the LDO regulator output pass device to prevent the possibility of over-temperature damage. The LDO regulator output will remain in a shutdown state until the internal die temperature falls back below the 140°C trip point. The interaction between the short-circuit and thermal protection systems allows the LDO regulator to withstand indefinite short-circuit conditions without sustaining permanent damage.
No-Load Stability
The AAT3201 is designed to maintain output voltage regulation and stability under operational noload conditions. This is an important characteristic for applications where the output current may drop to zero. An output capacitor is required for stability under no-load operating conditions. Refer to the Output Capacitor section of this datasheet for recommended typical output capacitor values.
Enable Function
The AAT3201 features an LDO regulator enable / disable function. This pin (EN) is active high and is compatible with CMOS logic. To assure the LDO regulator will switch on, the EN turn-on control level must be greater than 2.4V. The LDO regulator will go into the disable shutdown mode when the voltage on the EN pin falls below 0.6V. If the enable function is not needed in a specific application, it may be tied to VIN to keep the LDO regulator in a continuously on state.
Thermal Considerations and High Output Current Applications
The AAT3201 is designed to deliver a continuous output load current of 150mA under normal operating conditions. The limiting characteristic for the maximum output load safe operating area is essentially package power dissipation and the internal preset thermal limit of the device. In order to obtain high operating currents, careful device layout and circuit operating conditions need to be taken into account. The following discussions will assume the LDO regulator is mounted on a printed circuit board utilizing the minimum recommended footprint and the printed circuit board is 0.062-inch thick FR4 material with one ounce copper.
Short-Circuit and Thermal Protection
The AAT3201 is protected by both current limit and over-temperature protection circuitry. The internal short-circuit current limit is designed to activate when the output load demand exceeds the maximum rated output. If a short-circuit condition were
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AAT3201
150mA OmniPower™ LDO Linear Regulator
At any given ambient temperature (TA), the maximum package power dissipation can be determined by the following equation: -T T PD(MAX) = J(MAX) A θJA Constants for the AAT3201 are TJ(MAX), the maximum junction temperature for the device which is 125°C, and ΘJA = 150°C/W, the package thermal resistance. Typically, maximum conditions are calculated at the maximum operating temperature where TA = 85°C, under normal ambient conditions TA = 25°C. Given TA = 85°C, the maximum package power dissipation is 267mW. At TA = 25°C, the maximum package power dissipation is 667mW. The maximum continuous output current for the AAT3201 is a function of the package power dissipation and the input-to-output voltage drop across the LDO regulator. Refer to the following simple equation: PD(MAX) VIN - VOUT This formula can be solved for VIN to determine the maximum input voltage. PD(MAX) + (VOUT × IOUT) IOUT + IGND
VIN(MAX) =
The following is an example for an AAT3201 set for a 2.5 volt output: VOUT IOUT IGND = 2.5V = 150mA = 20µA 667mW + (2.5V × 150mA) 150mA + 20µA
VIN(MAX) =
VIN(MAX) = 6.95V From the discussion above, PD(MAX) was determined to equal 667mW at TA = 25°C. Thus, the AAT3201 can sustain a constant 2.5V output at a 150mA load current as long as VIN is ≤ 6.95V at an ambient temperature of 25°C. 5.5V is the maximum input operating voltage for the AAT3201, thus at 25°C the device would not have any thermal concerns or operational VIN(MAX) limits. This situation can be different at 85°C. The following is an example for an AAT3201 set for a 2.5 volt output at 85°C: VOUT IOUT IGND = 2.5V = 150mA = 20µA 267mW + (2.5V × 150mA) 150mA + 20µA
IOUT(MAX) <
For example, if VIN = 5V, VOUT = 2.5V, and TA = 25°C, IOUT(MAX)