AAT4282A SKYWORKS | Alldatasheet
Document overview
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Technical content
Features
VIN range: 1.5 V to 6.5 V Low RDS(ON): 60 m typical @ 5 V 140 m typical @ 1.5 V Slew rate turn-on time options: 1 ms 0.5 s 100 s Fast shutdown load discharge option Low quiescent current: Typical 1 A TTL/CMOS input logic level Temperature range: 40 °C to 85 °C FTDFN (8-pin, 2.0 mm 2.0 mm) package (MSL1, 260 ºC per JEDEC J-STD-020)
Description
The AAT4282A SmartSwitch™ is a member of the Skyworks Application Specific Power MOSFET (ASPM™) product family. The AAT4282A is a dual P-channel MOSFET power switch designed for high-side load-switching applications. Each MOSFET has a typical R DS(ON) of 60 m, allowing increased load switch current handling capacity with a low forward voltage drop. The device is available in three different versions with flexible turn-on and turn- off characteristics – from very fast to slew-rate limited. The standard 4282A (-1) version has a slew-rate limited turn-on load switch. The AAT4282A (-2) version features fast turn-on capability, typically less than 500 ns turn-on and 3 s turn-off times. The AAT4282A (-3) variation offers a shutdown load discharge circuit to rapidly turn off a load circuit when the switch is disabled. An additional feature is a slew-rate selector pin which can switch between fast and slow slew rate. All the AAT4282A load switch versions are designed to operate from 1.5 V up to 6.5 V, making them ideal for both 3 V and 5 V systems. Input logic levels are TTL and 2.5 V to 5 V CMOS compatible. The quiescent supply current is a very low 1 A. The AAT4282A is available in the Pb-free, low profile, 8-pin 2.0 mm 2.0 mm FTDFN package and is specified over the 40 °C to 85 °C ambient temperature range. A typical application circuit is shown in Figure 1. The pin configurations are shown in Figure 2. Signal pin assignments and selector guide are provided in Tables 1 and 2. Skyworks Green™ products are compliant with all applicable legislation and are halogen-free. For additional information, refer to Skyworks Definition of Green™ , document number SQ04-0074. INA INB OUTA OUTB INA INB ENA ENB FAST OUTA OUTB ON/OFF FAST/SLOW 1 F 1 F C3 0.1 F 0.1 FGND ON/OFF AAT4282A tc245 Figure 1. AAT4282A Typical Application Circuit
Figure 2. AAT4282A Pinout – 8-Pin, 2.0 mm 2.0 mm FTDFN Table 1. AAT4282A Signal Descriptions 1 INA This is the pin to the P-channel MOSFET sour ce for Switch A. Bypass to ground through a 1 F capacitor. INA is independent of INB. 4 INB This is the pin to the P-channel MOSFET sour ce for Switch B. Bypass to ground through a 1 F capacitor. INB is independent of INA. 5 OUTB This is the pin to the P-channel MOSFET drain connection. Bypass to ground through a 0.1 F capacitor.
6 GND Ground connection
7 FAST Active-High Input. Swit ches between FAST (logic H) and SLOW (Logic L) slew rate. 8 OUTA This is the pin to the P-channel MOSFET drain connection. Bypass to ground through a 0.1 F capacitor. Table 2. AAT4282A Selector Guide Note 1: Parts not available in stock, but can be ordered.
specifications are provided in Table 5. Table 3. AAT4282A Absolute Maximum Ratings (Note 1) parameters set at or below their nominal value. Exceeding any of the limits listed may result in permanent damage to the device. Note 2: Human Body Model is a 100 pF capacitor discharged through a 1.5 k resistor into each pin. Table 4. AAT4282A Thermal Information (Note 1) Note 1: Mounted on a AAT4282A demo board in still 25 °C air. or equipment, which can discharge without detection. Industry-standard ESD precautions should be used at all times.
Table 5. AAT4282A Electrical Specifications (Note 1) Note 1: Performance is guaranteed only under the conditions listed in this table. Note 2: Contact factory for other turn on and delay options.
Figure 18. AAT4282A Functional Block Diagram depending upon the specific requirements of an application. by careful control and monitoring of the MOSFET gate voltage. on slew rate control and no special output discharge features.
DATA SHEET • AAT4282A: SLEW RATE CONTROLLED LOAD SWITCH Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202231C • Skyworks Proprietary and Confiden tial Information • Products and Product Information are Subject to Change Without Notice • May 22, 2014 9 switch is disabled through the ON/OFF pin. Using the FAST input pin on the AAT4282A-3, the device can be manually switched to a slower slew rate. All versions of the AAT4282A operate with input voltages ranging from 1.5 V to 6.5 V. All versions of this device have extremely low operating current, making them ideal for battery- powered applications. The ON/OFF control pin is TTL compatible and also functions with 2.5 V to 5 V logic systems, making the AAT4282A an ideal level-shifting load switch. A functional block diagram is shown in Figure 18.
Application Information
A 1 F or larger capacitor is recommended for CIN in most applications. A CIN capacitor is not required for basic operation; however, it is useful in preventing load transients from affecting upstream circuits. C IN should be located as close to the device VIN pin as practically possible. Ceramic, tantalum, or aluminum electrolytic capacitors may be selected for C IN. There is no specific capacitor equivalent series resistance (ESR) requirement for C IN. However, for higher current 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. Output Capacitor For proper slew operation, a 0.1 F or greater capacitor is required between OUT and GND. Likewise, with the output capacitor, there is no specific capacitor ESR requirement. If desired, C OUT may be increased without limit to accommodate any load transient condition without adversely affecting the slew rate. Enable Function The AAT4282A features an enable/disable function. This pin (EN) is active high and is compatible with TTL or CMOS logic. To assure the load switch turns on, the EN control level must be greater than 1.4 V. The load switch goes into shutdown mode when the voltage on the EN pin falls below 0.4 V. When the load switch is in shutdown mode, the OUT pin is tri-stated, and quiescent current drops to leakage levels below 1 F. Reverse Output-to-Input Voltage Conditions and Protection Under normal operating conditions, a parasitic diode exists between the output and input of the load switch. The input voltage should always remain greater than the output load voltage, maintaining a reverse bias on the internal parasitic diode. Conditions where V OUT might exceed VIN should be avoided since this would forward bias the internal parasitic diode and allow excessive current flow into the OUT pin, possibly damaging the load switch. In applications where there is a possibility of V OUT exceeding VIN for brief periods of time during normal operation, the use of a larger value CIN capacitor is highly recommended. A larger value of CIN with respect to COUT will effect a slower CIN decay rate during shutdown, thus preventing VOUT from exceeding VIN. In applications where there is a greater danger of VOUT exceeding VIN for extended periods of time, it is recommended to place a Schottky diode from VIN to VOUT (connecting the cathode to VIN and anode to VOUT). The Schottky diode forward voltage should be less than 0.45 V. Thermal Considerations and High Output Current
Applications
The AAT4282A is designed to deliver a continuous output load current. The limiting characteristic for maximum safe operating output load current is package power dissipation. In order to obtain high operating currents, careful device layout and circuit operating conditions must be taken into account. The following discussions assumes the load switch is mounted on a printed circuit board utilizing the minimum recommended footprint as stated in the Printed Circuit Board Layout Recommendations section of this datasheet. At any given ambient temperature (T A), the maximum package power dissipation can be determined by the following equation: JA A)MAX(J D(MAX) TTP Constants for the AAT4282A are maximum junction temperature (TJ(MAX) = 125 °C, please note that the actual maximum junction temperature of AAT4282A is 150 °C. However, good design practice is to derate the maximum die temperature to 125 °C to prevent the possibility of over-temperature damage) and package thermal resistance ( JA = 70 °C/W). Worst case conditions are calculated at the maximum operating temperature, T A = 85 °C. Typical conditions are calculated under normal ambient conditions where TA = 25 °C. At TA = 85 °C, PD(MAX) = 571 mW. At TA = 25 °C, PD(MAX) = 1429 mW. The maximum continuous output current for the AAT4282A is a function of the package power dissipation and the RDS of the MOSFET at TJ(MAX). The maximum RDS of the MOSFET at TJ(MAX) is calculated by increasing the maximum room temperature RDS by the RDS temperature coefficient. The temperature coefficient (TC) is 2800 ppm/°C. Therefore, at 125°C: RDS(MAX) = RDS(25 °C) (1 + TC T) ( RDS(MAX) = 166.4 m
DATA SHEET • AAT4282A: SLEW RATE CONTROLLED LOAD SWITCH Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 10 May 22, 2014 • Skyworks Proprietary and Confidential Informat ion • Products and Product Information are Subject to Change Without Notice • 202231C For maximum current, refer to the following equation: DS )MAX(D OUT(MAX) R PI For example, if VIN = 5 V, RDS(MAX) = 166.4 m, and TA = 25 °C, IOUT(MAX) = 2.93 A. If the output load current were to exceed 2.93 A or if the ambient temperature were to increase, the internal die temperature would increase and the device would be damaged. Higher peak currents can be obtained with the AAT4282A. To accomplish this, the device thermal resistance must be reduced by increasing the heat sink area or by operating the load switch in a duty cycle manner. Duty cycles with peaks less than 2 ms in duration can be considered using the method described in the High Peak Output Current Applications section of this datasheet. High Peak Output Current Applications Some applications require the load switch to operate at a continuous nominal current level with short duration, high- current peaks. Refer to the I DM specification in Table 3 to ensure that the AAT4282A’s maximum pulsed current rating is not exceeded. The duty cycle for both output current levels must be taken into account. To do so, first calculate the power dissipation at the nominal continuous current level, and then add the additional power dissipation due to the short duration, high-current peak scaled by the duty factor. For example, a 4 V system using an AAT4282A which has channel A operates at a continuous 1 A load current level, and channel B operates at a continuous 100 mA load current level and has short 3 A current peaks, as in a GSM application. The current peak occurs for 576 s out of a 4.61 ms period. First, the current duty cycle is calculated: ms. s 100 xCycle Duty %Peak 614 576 %.Cycle Duty %Peak 512 The load current is 100 mA for 87.5% of the 4.61 ms period and 3 A for 12.5% of the period. Since the Electrical Characteristics do not report R DS(MAX) for 4 V operation, it must be approximated by consulting the chart of RDS(ON) vs VIN. The RDS reported for 5 V at 100 mA and 3 A can be scaled by the ratio seen in the chart to derive the RDS for 4 V VIN at 25 °C: Derated for temperature: For channel A, the power dissipation for a continuous 1 A load is calculated as follows: mW.m.ARIP DSOUT)CHA(D 717471741 For channel B, the power dissipation for 100 mA load is calculated as follows: DSOUT)MAX(D RIP 2 m.mAP )mA(D 7174100 100 mW.P )mA(D 751100 )mA(D)C/D%.(D PDC%P 100587 mW.P )C/D%.(D 531587 The power dissipation for 100 mA load at 87.5% duty cycle is 1.53 mW. Now the power dissipation for the remaining 12.5% of the duty cycle at 3 A is calculated: DSOUT)MAX(D RIP 2 m.AP )A(D 71743 3 mWP )A(D 15723 )A(D)C/D%.(D PDC%P 3512 mW.P )C/D%..(D 7196512 Finally, the total power dissipation for channels A and B is determined as follows: )A(D)mA(D)CHA(D)Total(D PPPP 3100 mW.mW.mW.P )Total(D 71965317174 mWP )Total(D 373 The maximum power dissipation for the AAT4282A operating at an ambient temperature of 85 °C is 373 mW. The device in this example has a total power dissipation of 571 mW. This is well within the thermal limits for safe operation of the device; in fact, at 85 °C, the AAT4282A handles a 3 A pulse for up to 25% duty cycle. At lower ambient temperatures, the duty cycle can be further increased. Printed Circuit Board Layout Recommendations For proper thermal management, and to take advantage of the low RDS(ON) of the AAT4282A: VIN and VOUT should be routed using wider than normal traces GND should be connected to a ground plane For best performance, CIN and COUT should be placed close to the package pins
DATA SHEET • AAT4282A: SLEW RATE CONTROLLED LOAD SWITCH Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202231C • Skyworks Proprietary and Confiden tial Information • Products and Product Information are Subject to Change Without Notice • May 22, 2014 13
Ordering Information
Model Name Part Marking (Note 1) Manufacturing Part Number (Note 2) Evaluation Board Part Number AAT4282A slew rate controlled load switch WKXYY AAT4282AIPS-3-T1 AAT4282AIPS-3-EVB Note 1: XYY = assembly and date code. Note 2: Sample stock is generally held on part numbers listed in BOLD. Copyright © 2012-2014 Skyworks Solutions, Inc. All Rights Reserved. Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. These materials, including the information contained herein, are provided by Skyworks as a service to its customers and may be used for informational purposes only by the customer. Skyworks assumes no responsibility for errors or omissions in these materials or the information contained herein. Skyworks may change its documentation, products, services, specifications or product descriptions at any time, without notice. Skyworks makes no commitment to update the materials or information and shall have no responsibility whatsoever for conflicts, incompatibilities, or other difficulties arising from any future changes. No license, whether express, implied, by estoppel or otherwise, is granted to any intellectual property rights by this document. Skyworks assumes no liability for any materials, products or information provided hereunder, including the sale, distribution, reproduction or use of Skyworks products, information or materials, except as may be provided in Skyworks Terms and Conditions of Sale. THE MATERIALS, PRODUCTS AND INFORMATION ARE PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, INCLUDING FITNESS FOR A PARTICULAR PURPOSE OR USE, MERCHANTABILITY, PERFORMANCE, QUALITY OR NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT; ALL SUCH WARRANTIES ARE HEREBY EXPRESSLY DISCLAIMED. SKYWORKS DOES NOT WARRANT THE ACCURACY OR COMPLETENESS OF THE INFORMATION, TEXT, GRAPHICS OR OTHER ITEMS CONTAINED WITHIN THESE MATERIALS. SKYWORKS SHALL NOT BE LIABLE FOR ANY DAMAGES, INCLUDING BUT NOT LIMITED TO ANY SPECIAL, INDIRECT, INCIDENTAL, STATUTORY, OR CONSEQUENTIAL DAMAGES, INCLUDING WITHOUT LIMITATION, LOST REVENUES OR LOST PROFITS THAT MAY RESULT FROM THE USE OF THE MATERIALS OR INFORMATION, WHETHER OR NOT THE RECIPIENT OF MATERIALS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Skyworks products are not intended for use in medical, lifesaving or life-sustaining applications, or other equipment in which the failure of the Skyworks products could lead to personal injury, death, physical or environmental damage. Skyworks customers using or selling Skyworks products for use in such applications do so at their own risk and agree to fully indemnify Skyworks for any damages resulting from such improper use or sale. Customers are responsible for their products and applications using Skyworks products, which may deviate from published specifications as a result of design defects, errors, or operation of products outside of published parameters or design specifications. Customers should include design and operating safeguards to minimize these and other risks. Skyworks assumes no liability for applications assistance, customer product design, or damage to any equipment resulting from the use of Skyworks products outside of stated published specifications or parameters. Skyworks and the Skyworks symbol are trademarks or registered trademarks of Skyworks Solutions, Inc., in the United States and other countries. Third-party brands and names are for identification purposes only, and are the property of their respective owners. Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference.