Datasheet
AS1374
200mA, Ultra-Low-Noise, High-PSRR, Dual Low Dropout Regulators
1 General Description
The AS1374 is a ultra-low-noise, low-dropout linear regulator with two seperated outputs. Specifically designed to deliver 200mA continuous output current at each output pin. The LDOs can achieve a low 120mV dropout for 200mA load current and are designed and optimized to work with low-cost, small-capacitance ceramic capacitors. An integrated P-channel MOSFET pass transistor allows the devices to maintain extremely low quiescent current (30µA). The AS1374 uses an advanced architecture to achieve ultra-low output voltage noise of 20µVRMS and a powersupply rejection-ratio of better than 85dB (@ 1kHz). Two active-High enable pins allows to switch on or off each output independently from each other. The AS1374 requires only 1µF output capacitor for stability at any load. The device is available in a 6-bump WLP package.
2 Key Features
! ! ! ! ! ! ! ! ! ! !
Preset Output Voltages: 1.2 to 3.6V (in 50mV steps) Output Noise: 20µVRMS @ 100Hz to 100kHz Power-Supply Rejection Ratio: 85dB @ 1kHz Low Dropout: 120mV @ 200mA Load Stable with 1µF Ceramic Capacitor for any Load Guaranteed 200mA Output Pull-Down Option in Shutdown (factory set) Extremely-Low Quiescent Current: 30µA Excellent Load/Line Transient Overcurrent and Thermal Protection 6-bump WLP Package
3 Applications
The devices are ideal for mobile phones, wireless phones, PDAs, handheld computers, mobile phone base stations, Bluetooth portable radios and accessories, wireless LANs, digital cameras, personal audio devices, and any other portable, battery-powered application.
Figure 1. AS1374 - Typical Application Circuit
Input 2V to 5.5V CIN 1µF
2 VDD
3 OUT 1
Output1 1.2V to 3.6V COUT1 1µF
6 EN 1
AS1374
1 OUT 2 COUT2 1µF
Output2 1.2V to 3.6V
4 EN 2
5 GND
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AS1374
Datasheet - P i n o u t
4 Pinout
Pin Assignments
Figure 2. Pin Assignments (Top View)
1
2
3
AS1374
4 5 6
Pin Descriptions
Table 1. Pin Descriptions Pin Number 1 2 3 4 5 6 Pin Name OUT 2 VDD OUT 1 EN 2 GND EN 1 Description Regulated Output Voltage 2. Bypass this pin with a capacitor to GND. See Capacitor Selection and Regulator Stability on page 11 for more details. Input Supply Regulated Output Voltage 1. Bypass this pin with a capacitor to GND. See Capacitor Selection and Regulator Stability on page 11 for more details. Enable 2. Pull this pin to logic low to disable Regulated Output 2 voltage. Ground Enable 1. Pull this pin to logic low to disable Regulated Output 1 voltage.
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AS1374
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Electrical Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2. Absolute Maximum Ratings Parameter VDD to GND OUT 1, OUT 2, EN 1, EN 2 to GND Output Short-Circuit Duration ESD Latch-Up Thermal Resistance ΘJA Operating Temperature Range Junction Temperature Storage Temperature Range -65 -40 2 100 201.7 +85 +150 +150 Min -0.3 -0.3 Max +7 VDD + 0.3 Infinite kV mA ºC/W ºC ºC ºC The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD-020D “Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). HBM MIL-Std. 883E 3015.7 methods @85°C, JEDEC 78 on PCB Units V V Comments
Package Body Temperature
+260
ºC
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AS1374
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
VIN = VOUT + 0.5V, VOUT = 2.85V, CIN = COUT = 1µF, TAMB = -40°C to +85ºC (unless otherwise specified). Typ values are at TAMB = +25ºC. Table 3. Electrical Characteristics Symbol VIN ΔVOUT IOUT IGND ILIMIT Parameter Input Voltage Range IOUT = 1mA, TAMB = +25ºC Output Voltage Accuracy Maximum Output Current Ground Current Current Limit Dropout Voltage IQ VLNR VLDR ISHDN PSRR
1
Condition
Min 2 -1 -1.5 -2.5 200
Typ
Max 5.5 +1 +1.5 +2.5
Unit V % mA
IOUT = 100µA to 200mA, TAMB = +25ºC IOUT = 100µA to 200mA each channel one channel on, IOUT = 50µA one channel on, IOUT = 200mA OUT = short 2.5V ≤ VOUT < 3V, IOUT = 100mA both channels on, IOUT = 0.05mA
25 30 210 300 60 30 50 0.02 0.0005 0.01 85 65 50 20 0.01
50 55 400 120 90
µA µA mA mV µA %/V %/mA
Quiescent Current Line Regulation Load Regulation Shutdown Current Ripple Rejection Output Noise Voltage (RMS)
both channels on, VIN = VOUTNOM - 0.1V, IOUT = 0mA VIN = (VOUT +0.5V) to 5.5V, IOUT = 1mA IOUT = 1 to 200mA OUT 1 and OUT 2 disable f = 1kHz, IOUT = 10mA f = 10kHz, IOUT = 10mA f = 100kHz, IOUT = 10mA f = 100Hz to 100kHz, ILOAD = 20mA
2
µA dB µV µA µs
Enable Enable Input Bias Current Enable Exit Delay
2
both channels initially off one channel initially off 1.4
150 200 0.4
Enable Logic Low Level Enable Logic High Level Thermal Protection TSHDN ΔTSHDN Thermal Shutdown Temperature Thermal Shutdown Hysteresis 160 15
V V
ºC ºC
1. Dropout is defined as VIN - VOUT when VOUT is 100mV below the value of VOUT for VIN = VOUT + 0.5V. 2. Time needed for VOUT to reach 90% of final value.
Note: All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality Control) methods.
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AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
VIN = VOUT + 0.5V, VOUT = 2.85V, CIN = COUT = 1µF, TAMB = 25°C (unless otherwise specified). Figure 3. Output Voltage vs. Temperature
2.88 2.87
Figure 4. Output Voltage vs. Input Voltage
2.88 2.87
Output Voltage (V)
2.86 2.85 2.84 2.83
CH1 CH2
Output Voltage (V)
2.86 2.85 2.84
Iload = 1mA
2.83 2.82 3.35
Iload = 10mA Iload = 100mA Iload = 200mA
2.82 -45 -30 -15
0
15
30
45
60
75
90
3.85
4.35
4.85
5.35
Temperature (°C) Figure 5. Output Voltage vs. Load Current
2.88
-40°C
Input Voltage (V) Figure 6. Output Voltage vs. Input Voltage - Dropout
2.86
+25°C +85°C
2.87
2.84
Output Voltage (V)
Output voltage (V)
2.86 2.85 2.84 2.83 2.82 2.81 2.8 0 25 50 75 100 125 150 175 200
2.82 2.8 2.78 2.76
Iload = 100mA
2.74 2.72 2.75
Iload = 200mA
2.8
2.85
2.9
2.95
3
3.05
Load Current (mA) Figure 7. Dropout Voltage vs. Load Current
150 125
Input Voltage (V) Figure 8. PSRR vs. Frequency
100 90 80
Dropout Voltage (V)
PSRR (dB)
-40°C +25°C +85°C
100 75 50 25 0 25 50 75 100 125 150 175 200
70 60 50 40 30 20 100
1000
10000
100000
Load Current (mA) www.austriamicrosystems.com Revision 1.03
Frequency (Hz) 5 - 14
AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
Figure 9. Ground Pin Current vs. Load Current
33 32
Figure 10. Ground Pin Current vs. Temperature
30
Ground Pin Current (µA)
31 30 29 28 27 26 25 24 23 0 25 50 75 100 125 150 175 200
-40°C +25°C +85°C
Ground Pin Current (µA)
29
28
27
26
25 -45 -30 -15
0
15
30
45
60
75
90
Load Current (mA)
Temperature (°C)
Figure 11. Ground Pin Current vs. Input Voltage; one Channel on, no Load
60 50 40 30 20 10 0 0 1 2 3 4 5
-40°C +25°C +85°C
Figure 12. Ground Pin Current vs. Input Voltage; one Channel on, ILOAD = 200mA
60 50 40 30 20 10 0 3.35
-40°C +25°C +85°C
Ground Pin Current (µA)
Ground Pin Current (µA)
3.85
4.35
4.85
5.35
Input Voltage (V) Figure 13. Ground Pin Current vs. Input Voltage; both Channels on, no Load
100 90
Input Voltage (V) Figure 14. Ground Pin Current vs. Input Voltage; both Channels on, ILOAD = 200mA
100 90
Ground Pin Current (µA)
80 70 60 50 40 30 20 10 0 0 1 2 3 4 5
-40°C +25°C +85°C
Ground Pin Current (µA)
80 70 60 50 40 30 20 10 0 3.35 3.85 4.35 4.85
-40°C +25°C +85°C
5.35
Input Voltage (V)
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AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
Figure 15. Shutdown Current vs. Input Voltage
60
-40°C
Figure 16. Load Regulation vs. Temperature
0
Shutdown Current (nA)
50 40 30 20 10 0 0.5 1
Load Regulation (% / mA)
+25°C +85°C
-0.0002 -0.0004 -0.0006 -0.0008 -0.001 -0.0012 -45 -30 -15
CH1 CH2
1.5
2
2.5
3
3.5
4
4.5
5
5.5
0
15 30
45
60
75
90
Input Voltage (V)
Temperature (°C)
Figure 17. Line Regulation vs. Load Current
0.2 0.15
Figure 18. Line Regulation vs. Temperature
0.2 0.15
Line Regulation (% / V)
0.1 0.05 0 -0.05 -0.1 -0.15 -0.2 0 25 50 75 100 125 150 175 200
-40°C +25°C +85°C
Line Regulation (% / V)
0.1 0.05 0 -0.05 -0.1 -0.15 -0.2 -45 -30 -15
Iload = 1mA Iload = 10mA Iload = 100mA Iload = 200mA
0
15
30
45
60
75
90
Load Current (mA)
Temperature (°C)
Figure 19. Load Transient Response, Crosstalk, between CH1 and CH2, IOUT = 200mA
Figure 20. Load Transient Response near Dropout, IOUT = 200mA
10mV/Div
VOUT1
10mV/Div
VOUT2
100mA/Div
20µs/Div
20µs/Div
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IOUT1
IOUT1
20mV/Div
VOUT1
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AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
Figure 21. Line Transient Response
Figure 22. Shutdown
10mV/Div
VOUT1
VOUT1
500mV/Div
VIN
100µs/Div
100µs/Div
Figure 23. Startup of CH1 when CH2 is Off
Figure 24. Startup of CH1 when CH2 is On
2V/Div
1V/Div
VOUT1
100mA/Div
VOUT1
20µs/Div
20µs/Div
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100mA/Div
IIN
IIN
1V/Div
2V/Div
EN1
EN1
50mA/Div
IOUT1
1V/Div
2V/Div
EN1
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AS1374
Datasheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
The AS1374 is an ultra-low-noise, low-dropout, low-quiescent current linear-regulator with two seperated outputs specifically designed for space-limited applications. These device can supply loads up to 200mA. As shown in Figure 25, the AS1374 consist of an integrated bandgap core, error amplifier, P-channel MOSFET pass transistor, and internal feedback voltage-divider. The output voltage is fed back through an internal resistor voltage-divider connected to pin OUT. Additional blocks include a current limiter, thermal sensor, and enable logic.
Internal Voltage Reference
The bandgap reference is connected to the error amplifier’s inverting input. The error amplifier compares this reference with the feedback voltage and amplifies the difference. If the feedback voltage is lower than the reference voltage, the pass-transistor gate is pulled low. This allows more current to pass to the output and increases the output voltage. If the feedback voltage is too high, the pass transistor gate is pulled high, allowing less current to pass to the output.
Internal P-Channel Pass Transistor
The AS1374 feature a 0.6Ω (typ) P-channel MOSFET pass transistor, which provides several advantages over similar designs using a PNP pass transistor, including prolonged battery life. The P-channel MOSFET does not require a base driver, thus quiescent current is dramatically reduced. The AS1374 do not exhibit problems associated with typical PNP-based LDOs, and consume only 30µA of quiescent current in light load and 50µA in dropout (see Typical Operating Characteristics on page 5).
Output Voltage
The AS1374 deliver preset output voltages from 1.2V to 3.6V, in 50mV increments (see Ordering Information on page 13).
Enable
The AS1374 feature an actice high enable mode to shutdown each output indepentend. Driving EN 1 low disables Output 1, driving EN 2 low disables Output 2. The disabled Output enters a high-impedance state.
Figure 25. AS1374 - Block Diagram
-
EN 1
Enable Logic CH1
+
OUT 1
Overcurrent Protection CH1
VDD
Thermal Protection
Common Logic
Bandgap
Trimmable Reference
GND
Overcurrent Protection CH2
EN 2
Enable Logic CH2
+ -
OUT 2
AS1374
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AS1374
Datasheet - D e t a i l e d D e s c r i p t i o n
Current Limit
The AS1374 include a current limiting circuitry to monitor and control the P-channel MOSFET pass transistor’s gate voltage, thus limiting the device output current to 300mA.
Note: See Table 3 on page 4 for the recommended min and max current limits. The output can be shorted to ground indefinitely without causing damage to the device.
Thermal Protection
Integrated thermal protection circuitry limits total power dissipation in the AS1374. When the junction temperature (TJ) exceeds +160ºC, the thermal sensor signals the shutdown logic, turning off the P-channel MOSFET pass transistor and allowing the device to cool down. The thermal sensor turns the pass transistor on again after the device’s junction temperature drops by 15ºC, resulting in a pulsed output during continuous thermal-overload conditions.
Note: Thermal protection is designed to protect the devices in the event of fault conditions. For continuous operation, do not exceed the absolute maximum junction temperature rating of +150ºC.
Operating Region and Power Dissipation
The AS1374 maximum power dissipation is dependant on the thermal resistance of the case and PCB, the temperature difference between the die junction and TAMB, and airflow rate. Power dissipation across the device is calculated as: PD = IOUT (VIN - VOUT) (EQ 1) The maximum power dissipation is calculated:
PDMAX = (TJ - TAMB)/θJA Where: TJ - TAMB is the temperature difference between the AS1374 die junction and the surrounding air; θJA is the thermal resistance through the circuit board, copper traces, and other materials to the surrounding. (EQ 2)
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AS1374
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9 Application Information
Capacitor Selection and Regulator Stability
For normal operation, use a 1µF capacitor at pin VDD and a 1µF capacitor at pin OUT. Larger input capacitor values and lower ESR provide better noise rejection and line-transient response. Reduce output noise and improve load-transient response, stability, and power-supply rejection by using large output capacitors.
Note: Some ceramic dielectrics exhibit large capacitance and ESR variation with temperature. With dielectrics such as Z5U and Y5V, it may be necessary to use a 2.2µF or larger output capacitor to ensure stability at temperatures below -10°C. With X7R or X5R dielectrics, 1µF is sufficient at all operating temperatures.
Noise, PSRR, and Transient Response
The AS1374 is designed to deliver ultra-low noise and high PSRR, as well as low dropout and low quiescent currents in battery-powered systems. The power-supply rejection is 85dB at 1kHz and 50dB at 100kHz. (see Figure 8 on page 5). When operating from sources other than batteries, improved supply-noise rejection and transient response can be achieved by increasing the values of the input and output capacitors, and through passive filtering techniques. The Figure 19, Figure 20 on page 7 and Figure 21 on page 8 show the AS1374 Load- and Line- Transient Responses.
Dropout Voltage
The AS1374 minimum dropout voltage determines the lowest usable supply voltage. In battery-powered systems, this determines the useful end-of-life battery voltage. Since the AS1374 use a P-channel MOSFET pass transistor, the dropout voltage is a function of drain-to-source onresistance (RDS(ON)) multiplied by ILOAD (see Figure 7 on page 5).
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AS1374
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
10 Package Drawings and Markings
The devices are available in a 6-bump WLP package.
Figure 26. 6-bump WLP Package
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AS1374
Datasheet - O r d e r i n g I n f o r m a t i o n
11 Ordering Information
The devices are available as the standard products shown in Table 4.
Table 4. Ordering Information Ordering Code Marking Output Voltage 1 Output Voltage 2 Delivery Form Package
AS1374-BWLT-285 AS1374-BWLT1833 AS1374-BWLT1218
ASSH ASSJ ASSK
2.85V 1.8V 1.2V
2.85V 3.3V 1.8V
Tape and Reel Tape and Reel Tape and Reel
6-bump WLP 6-bump WLP 6-bump WLP
Non-standard devices from 1.2V to 3.6V are available in 50mV steps. For more information and inquiries contact http://www.austriamicrosystems.com/contact
Note: All products are RoHS compliant and Pb-free. Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect
For further information and requests, please contact us mailto:sales@austriamicrosystems.com or find your local distributor at http://www.austriamicrosystems.com/distributor
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AS1374
Datasheet
Copyrights
Copyright © 1997-2009, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services.
Contact Information
Headquarters austriamicrosystems AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 Fax: +43 (0) 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: http://www.austriamicrosystems.com/contact
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