AAT4285 SKYWORKS | Alldatasheet

Document overview

  • Manufacturer or author: Provided By alldatasheet.com(free datasheet download site)
  • PDF pages: 11

Technical content

Features

  • V IN Range: 3.0V to 13.2V
  • Low RDS(ON) ▪ 240mW Typical @ 12V ▪ 310mW Typical at 5V
  • 100µs Slew Rate Turn-on Time
  • Fast Shutdown Load Discharge
  • Low Quiescent Current ▪ Typically 25µA ▪ 1µA Maximum in Shutdown
  • TTL/CMOS Input Logic Level
  • Temperature Range: -40°C to +85°C
  • 8-pin SC70JW Package

Applications

  • 2 Cell Lithium-Ion Batteries
  • Camcorders
  • Handheld Test Equipment
  • Load Switching Typical Application AAT4285 COUT 0.1µF CIN 1µF OUTIN GND × 4 VOUT GNDGND VIN ON/OFF IN ON

12V Slew Rate Controlled Load Switch Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202232A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 31, 2012 Pin Descriptions Pin # Symbol Function 1,2 IN P-channel MOSFET source. Bypass to ground through a 1µF capacitor. 3 OUT P-channel MOSFET drain connection. Bypass to ground through a 0.1µF capacitor. 4 ON/OFF Active high enable input. A logic low turns the switch off and the device consumes less than 1µA of current. Logic high resumes normal operation. 5, 6, 7, 8 GND Ground connection Pin Configuration SC70JW-8 (Top View) IN OUT ON/OFF GND GND GND GND IN 1

12V Slew Rate Controlled Load Switch Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202232A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 31, 2012 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 an FR4 board. Absolute Maximum Ratings1 Symbol Description Value Units VIN IN to GND -0.3 to 14 V VON ON/OFF to GND -0.3 to 14 V VOUT OUT to GND -0.3 to VIN + 0.3 V IMAX Maximum Continuous Switch Current 1.7 A IDM Maximum Pulsed Current 3.4 A TJ Operating Junction Temperature Range -40 to 150 °C Thermal Characteristics2 Symbol Description Value Units qJA Thermal Resistance 140 °C/W PD Maximum Power Dissipation 714 mW

12V Slew Rate Controlled Load Switch Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202232A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 31, 2012 1. The AAT4285 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correla - tion with statistical process controls. 2. Contact factory for other turn-on and delay options. Electrical Characteristics1 VIN = 12V, TA = -40°C to +85°C, unless otherwise noted. Typical values are T A = 25°C. Symbol Description Conditions Min Typ Max Units VIN Operation Voltage 3.0 13.2 V VUVLO Under-Voltage Lockout 2.7 3.0 V VUVLO(hys) Under-Voltage Lockout Hysteresis 250 V IQ Quiescent Current ON/OFF = Active, IOUT = 0 25 50 µA IQ(OFF) Off Supply Current ON/OFF = Inactive, OUT = Open 1.0 µA ISHD Off Switch Current ON/OFF = GND, VOUT = 0 0.1 1.0 µA RDS(ON) On Resistance VIN = 12V 240 400 mWVIN = 5V 310 500 VIN = 3.3V 380 TCRRDS On Resistance Temperature Coefficient 2800 ppm/°C TD(ON) Output Turn-On Delay Time2 RLOAD = 20W, TA = 25°C 20 40 µs TON Turn-On Rise Time2 RLOAD = 20W, TA = 25°C 100 250 µs TD(OFF) Output Turn-Off Delay Time2 RLOAD = 20W, TA = 25°C 1 10 µs RPD Output Pull-Down Resistance During OFF ON/OFF Inactive, TA = 25°C 520 800 W VON(L) ON/OFF Input Logic Low Voltage VIN = 3V to 13V 0.4 V VON(H) ON/OFF Input Logic High Voltage VIN = 3V to 13V 1.6 V ION ON/OFF Leakage Current VON/OFF = 13V -1.0 1.0 µA

12V Slew Rate Controlled Load Switch Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202232A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 31, 2012 Typical Characteristics Quiescent Current vs. Temperature Temperature (°C) Quiescent Current (µA) -40 -15 10 35 60 85 VIN = 12V VIN = 5V VIN = 4.2V VIN = 3.3V Quiescent Current vs. Input Voltage Input Voltage (V) Quiescent Current (µA) 0246 81 01 21 4 RDS(ON) vs. Temperature Temperature (°C) RDS(ON) (mΩ ) 100 150 200 250 300 350 400 450 500 -40 -15 10 35 60 85 VIN = 3.3V VIN = 4.2V VIN = 12VVIN = 5V RDS(ON) vs. Input Voltage Input Voltage (V) RDS(ON) (mΩ) 220 260 300 340 380 420 34 56789 10 11 12 0.5A 0.1A ON/OFF Threshold Low vs. Input Voltage Input Voltage (V) ON/OFF Threshold (V) 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 357 91 11 3 -40°C 25°C 85°C ON/OFF Threshold High vs. Input Voltage Input Voltage (V) ON/OFF Threshold (V) 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 357 91 11 3 -40°C 25°C 85°C

12V Slew Rate Controlled Load Switch Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202232A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 31, 2012 Typical Characteristics Output Pull-Down Resistance vs. Temperature Temperature (°C) Resistance (Ω ) 400 450 500 550 600 650 700 750 800 -40 -15 10 35 60 85 VIN = 3.3V VIN = 12VVIN = 5V VIN = 4.2V Turn-On (VIN = 12V; 600mA Load) Time (25µs/div) ON/OFF (5V/div) VOUT (5V/div) IOUT (500mA/div) Turn-Off (VIN = 12V; 600mA Load) Time (10µs/div) ON/OFF (5V/div) VOUT (5V/div) IOUT (500mA/div)

12V Slew Rate Controlled Load Switch Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202232A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 31, 2012 Functional Description The AAT4285 is a slew rate controlled P-channel MOSFET power switch designed for high-side load switching applications. The device operates with input voltages ranging from 3.0V to 13.2V, making it ideal for single- or multi-cell battery-powered applications. In cases where the input voltage drops below 3.0V, the AAT4285 MOSFET is protected from entering the saturated region of operation by automatically shutting down. In addition, the TTL compatible ON/ OFF pin makes the AAT4285 an ideal level-shifted load switch. The slew rate controlling feature eliminates inrush current when the MOSFET is turned on, allowing the AAT4285 to operate with a small input capacitor, or no input capacitor at all. During slew- ing, the current ramps linearly until it reaches the level required for the output load condition. The proprietary control method works by careful control and monitoring of the MOSFET gate voltage. When the device is switched ON, the gate voltage is quickly increased to the thresh - old level of the MOSFET. Once at this level, the current begins to slew as the gate voltage is slowly increased until the MOSFET becomes fully enhanced. Once it has reached this point, the gate is quickly increased to the full input voltage and RDS(ON) is minimized. Applications Information Input Capacitor A 1µF or larger capacitor is typically recommended for CIN in most applications. A C IN capacitor is not required for basic operation. However, CIN is useful in preventing load transients from affecting upstream circuits. C IN should be located as close to the device V IN pin as prac- tically possible. Ceramic, tantalum, or aluminum electrolytic capacitors may be selected for C IN. There is no specific capacitor ESR requirement for C IN. However, for higher current operation, ceramic capacitors are recommended for C IN 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 0.1µF capacitor or greater between OUT and GND is recommended. The output capacitor has no specific capacitor type or ESR requirement. If desired, C OUT may be increased without limit to accommodate any load transient condi - tion without adversely affecting the device turn-on slew rate time. Functional Block Diagram Under- Voltage Lockout Level Shift IN ON/OFF OUT GND GND GND GND Turn-On Slew Rate Control

12V Slew Rate Controlled Load Switch Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202232A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 31, 2012 Enable Function The AAT4285 features an enable / disable function. This pin (ON/ OFF) is compatible with both TTL and CMOS logic. 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 cur- rent flow into the OUT pin and possibly damage the load switch. In applications where there is a possibility of V OUT exceeding V IN for brief periods of time during normal operation, the use of a larger value C IN capacitor is highly recommended. A larger value of C IN with respect to COUT will affect a slower C IN decay rate during shut - down, thus preventing VOUT from exceeding VIN. In appli- cations where there is a greater danger of VOUT exceeding VIN for extended periods of time, it is recommended to place a Schottky diode from IN to OUT (connecting the cathode to IN and anode to OUT). The Schottky diode forward voltage should be less than 0.45V. Thermal Considerations and High Output Current Applications The AAT4285 is designed to deliver a continuous output load current. The limiting characteristic for maximum safe operating output load current is package power dis- sipation. 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 load switch is mounted on a printed circuit board utilizing the minimum recommended footprint, as stated in the Layout Considerations section of this datasheet. At any given ambient temperature (T A), the maximum package power dissipation can be determined by the fol- lowing equation: PD(MAX) = TJ(MAX) - TA θJA Constants for the AAT4285 are maximum junction tem - perature, T J(MAX) = 125°C, and package thermal resis - tance, θJA = 140°C/W. Worst case conditions are calcu - lated at the maximum operating temperature where TA = 85°C. Typical conditions are calculated under normal ambient conditions where T A = 25°C. At T A = 85°C, PD(MAX) = 286mW. At TA = 25°C, PD(MAX) = 714mW. The maximum continuous output current for the AAT4285 is a function of the package power dissipation and the RDS of the MOSFET at T J(MAX). The maximum R DS of the MOSFET at T J(MAX) is calculated by increasing the maxi - mum room temperature R DS by the R DS temperature coefficient. The temperature coefficient (TCR RDS) is 2800ppm/°C. Therefore, MAX R DS 125°C = RDS 25°C · (1 + TCR RDS · ΔT) MAX R DS 125°C = 240mΩ · (1 + 0.0028 · (125°C - 25°C)) = 307mΩ For maximum current, refer to the following equation: IOUT(MAX) < PD(MAX) RDS For example, if V IN = 12V, R DS(MAX) = 307mΩ and T A = 25°C, IOUT(MAX) = 1.53A. If the output load current were to exceed 1.53A 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 AAT4285. 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 cycled manner. 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. The duty cycle for both output cur - rent levels must be taken into account. To do so, first calculate the power dissipation at the nominal continu - ous current level, and then add in the additional power dissipation due to the short duration, high-current peak scaled by the duty factor. For example, a 12V system using an AAT4285 operates at a continuous 100mA load current level and has short 2A current peaks. The current peak occurs for 500µs out of a 5ms period.

12V Slew Rate Controlled Load Switch Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202232A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 31, 2012 First, the current duty cycle is calculated: % Peak Duty Cycle = % Peak Duty Cycle = x 100 = 10% 500µs 5.0ms The load current is 100mA for 90% of the 5ms period and 2A for 10% of the period. De-rated for temperature: The power dissipation for a 100mA load is calculated as follows: PD(MAX) = IOUT 2 · RDS PD(100mA) = (100mA)2 · 307mΩ PD(100mA) = 3.07mW PD(90%D/C) = %DC · PD(100mA) PD(90%D/C) = 2.76mW The power dissipation for 100mA load at 90% duty cycle is 2.76mW. Now the power dissipation for the remaining 10% of the duty cycle at 2A is calculated: PD(MAX) = IOUT 2 · RDS PD(2A) = (2A)2 · 307mΩ PD(2A) = 1.23W PD(10%D/C) = %DC · PD(2A) PD(10%D/C) = 123mW The power dissipation for 2A load at 10% duty cycle is 123mW. Finally, the two power figures are summed to determine the total true power dissipation under the varied load. PD(TOTAL) = PD(100mA) + PD(2A) PD(TOTAL) = 2.76mW + 123mW PD(TOTAL) = 125.76mW The maximum power dissipation for the AAT4285 oper - ating at an ambient temperature of 85°C is 286mW. The device in this example will have a total power dissipation of 123mW. This is well within the thermal limits for safe operation of the device; in fact, at 85°C, the AAT4285 will handle a 2A pulse for up to 23% 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 R DS(ON) of the AAT4285, a few circuit board layout rules should be followed: V IN and V OUT should be routed using wider than normal traces, and GND should be connected to a ground plane. To maximize package thermal dissipation and power handling capacity of the AAT4285 SC70JW-8 package, the ground plane area connected to the ground pins should be made as large as possible. For best performance, C IN and C OUT should be placed close to the package pins. Evaluation Board Layout The AAT4285 evaluation board layout follows the printed circuit board layout recommendations and can be used for good application guide. Refer to Figures 1 through 3. Note: Board layout shown is not to scale.

12V Slew Rate Controlled Load Switch Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com 202232A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 31, 2012 Copyright © 2012 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. Sky - works 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 here- under, 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, IN - CLUDING 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 en- vironmental 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 pub- lished 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, the Skyworks symbol, and “Breakthrough Simplicity” 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. 1. XYY = assembly and date code. 2. Sample stock is generally held on part numbers listed in BOLD.

Ordering Information

Package Marking1 Part Number (Tape and Reel)2 SC70JW-8 UAXYY AAT4285IJS-3-T1 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.

Package Information

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 All dimensions in millimeters.