AAT4686 ANALOGICTECH | Alldatasheet

Document overview

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Technical content

Features

  • Over-Voltage Protection up to 28V
  • ( Fixed or Adjustable) Over-Voltage Protection Threshold
  • Fast OVP Response: ▪ 1 μs (Max) to Over-Voltage Transient
  • Low Operation Quiescent Current ▪ 30 μA Typical ▪ 1 μA Max in Shutdown (Disabled)
  • Drives External P-Channel MOSFETs
  • Under-Voltage Lockout
  • Temperature Range: -40 to 85°C
  • Available in SC70JW-8 Package

Applications

  • Cell Phones
  • Digital Still Cameras
  • GPS
  • MP3 Players
  • Personal Data Assistants (PDA)
  • USB Hot Swap / Live Insertion Devices Typical Application 1μF IN FLTEN GATE GND VIN Fault Flag VOUT 3.75V – 28V +5V Fixed Version* 1μF IN OVP FLTEN GATE GND VIN Fault Flag VOUT 3.75V – 28V +5V Adjustable Version * Contact manufacturer for available options.

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET AAT4686 MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Pin Descriptions Pin # Symbol FunctionFixed Adj. 1 IN Power input pin. Connect a 1 μF capacitor from IN to GND. 2 GATE Gate connection to external P-channel MOSFET. 3 GND Ground. N/C 4 NC/OVP Fixed version: not connected. Adjustable version: Over-voltage protection threshold input. 5 FLT Over-voltage fault reporting. 6, 7, 8 EN Enable input, active low. When connected high, the device shuts down and draws less than 1.0μA of current. An internal pull-down resistor is connected to this pin. Pin Configuration Fixed OVP Trip Adjustable OVP Trip Voltage Version Voltage Version SC70JW-8 SC70JW-8 (Top View) (Top View) GATE GND N/C EN EN EN FLT IN 1 GATE GND OVP EN EN EN FLT IN 1

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET AAT4686 MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Absolute Maximum Ratings1 Symbol Description Value Units VIN IN to GND -0.3 to 28 V VOVP OVP to GND -0.3 to 6.5 V VFLT, VEN FLT, EN to GND -0.3 to 6.5 V VGATE GATE to GND 28 V TJ Operating Junction Temperature Range -40 to 150 °C Thermal Characteristics Symbol Description Value Units θJA Maximum Thermal Resistance2 225 °C/W PD Maximum Power Dissipation2, 3 440 mW 1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at c onditions 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 FR4 board. 3. Derated 4.4mW/°C above 25°C

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET AAT4686 MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Electrical Characteristics1 VIN = 5V, TA = -40° to 85°C unless otherwise noted. Typical values are at T A = 25°C. Symbol Description Conditions Min Typ Max Units VIN Normal Operation Voltage Range 3 14 V IQ Operation Quiescent Current VIN = 5V, EN = 0V, IOUT = 0 30 50 μA ISD(OFF) Shutdown Supply Current EN = IN, VIN = 5.5V, VOUT = 0 1 μA VUVLO Under-Voltage Lockout Threshold Rising Edge 3 3.3 V VUVLO_HYS Under-Voltage Lockout Hysteresis 0.1 V Adjustable VOVP_TH Over-Voltage Lockout Threshold, OVP Pin Rising Edge 1.083 1.1 1.117 V VOVP_HYS Over-Voltage Lockout Threshold Hysteresis, OVP 20 mV Fixed VOVPT Over-Voltage Protection Trip Voltage Rising Edge 6.5 V VOVP_HYS Over-Voltage Protection Trip Point Hysteresis, IN Pin 120 mV Gate Output VGHL Gate Voltage High Level EN = VIN VIN V VGLL Gate Voltage Low Level2 VIN - 5V V IG Gate Current 1 μA Logic VEN(L) EN Input Low Voltage 0.4 V VEN(H) EN Input High Voltage 1.6 V IEN EN Input Leakage V EN = 5.5V or 0V 0.5 2.0 μA FLTOL FLT Output Voltage Low IFLT = 1mA 0.4 V FLTIOL FLT Output Leakage Current 1 μA TBLK_FLT FLT Blanking Time From De-assertion of OV 5 10 15 ms TD_FLT FLT Assertion Delay Time from Over-Voltage (OV) From Assertion of OV 1 μs TRESP_OV Over-Voltage Response Time VIN = 5V, VOVP Rise to 1.13V from 1.07V in 1ns 0.7 μs TON Gate Turn On Delay Time V IN = 5V; CG = 400pF 10 ms TR Gate Turn On Fall Time V IN = 5V; CG = 400pF 4 ms TOFF Gate Turn Off Delay Time V IN = 5V; CG= 400pF 6 ms 1. The AAT4686 is guaranteed to meet performance specification over the -40 to 85°C operating temperature range and are assured by design, characterization and correlation with statistical process controls. 2. VGS (i.e. VIN_GATE) is clamped to typical 5V.

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET AAT4686 MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Typical Characteristics Operation Quiescent Current vs. Supply Voltage Supply Voltage (V) Quiescent Current (µA) 3 4 5 6 7 8 9 1 01 11 21 31 Operation Quiescent Current vs. Temperature Temperature (°C) Quiescent Current (µA) -40 -15 10 35 60 8 5 Shutdown Supply Current vs. Supply Voltage Supply Voltage (V) Shutdown Supply Current (µA) 0.0 0.6 1.2 1.8 2.4 3.0 2 4 6 8 10 12 14 16 18 20 22 24 26 2 8 Shutdown Supply Current vs. Temperature Temperature (°C) Shutdown Supply Current (µA) 0.00 0.07 0.14 0.21 0.28 0.35 -40 -15 10 35 60 85 FLT Blanking Time vs. Temperature Temperature (°C) FLT Blanking Time (ms) -40 -15 10 35 60 8 FLT Blanking Time (VIN = 5.0V) Time (2ms/div) VOUT (1V/div) FLT (2V/div) OVP (100mV/div) 4.3V 5.0V 1.15V

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET AAT4686 MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Typical Characteristics Undervoltage Lockout Threshold vs. Temperature Temperature (°C) UVLO Threshold (V) 1.50 2.00 2.50 3.00 3.50 4.00 -40 -15 10 35 60 85 VIN Falling VIN Rising Over-Voltage Response Time vs. Temperature Temperature (°C) Over-Voltage Response Time (ns) 550 600 650 700 750 800 -40 -15 10 35 60 8 5 Over-Voltage Lockout Threshold (Adjustable Version) vs. Temperature Temperature (°C) VOVP 1.06 1.07 1.08 1.09 1.10 1.11 1.12 -40 -15 10 35 60 8 5 VOVP_TH VOVP_HYS EN Input High Voltage vs. Supply Voltage Supply Voltage (V) VEN(H) (V) 0.6 0.7 0.8 0.9 1.0 1.1 3 4 5 6 7 8 9 1 01 11 21 31 4 85°C 25°C -40°C EN Input Low Voltage vs. Supply Voltage Supply Voltage (V) VEN(L) (V) 3 4 5 6 7 8 9 1 01 11 21 31 4 0.6 0.7 0.8 0.9 1.0 1.1 -40°C 25°C 85°C Turn Off Delay Time (VIN = 5.0V, RO = 10ΩΩ) Time (2ms/div) VOUT (2V/div) EN (2V/div) 0V 4.84V

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET AAT4686 MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Typical Characteristics Turn On Delay Time (VIN = 5.0V, RO = 10ΩΩ) Time (2ms/div) VOUT (2V/div) EN (2V/div) 0V

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET AAT4686 MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Functional Description In conjunction with an external P-channel power MOSFET, the AAT4686 provides up to 28V over-voltage protection when powering low-voltage systems such as cell phones, MP3, and PDAs or when charging Lithium-Ion batteries from a poorly regulated supply. The P-channel MOSFET is inserted between the power supply or charger source and the load to be protected. The AAT4686 IC consists of a P-channel MOSFET slew-rate controlled driver, under-voltage lockout protection, over-voltage monitor, fast shutdown circuitry, and a fault output flag. In normal operation, the P-channel MOSFET is controlled by the AAT4686, connecting and disconnecting the power supply from IN to OUT. A low resistance MOSFET is used to minimize the voltage drop between the volt- age source and the load and to reduce the power dissi- pation. Any P-channel MOSFET can be used; however, the turn-on and turn-off speed will vary inversely pro- portionately to the MOSFET ON-resistance. When the input voltage exceeds the programmed voltage limit (internally set or externally by a voltage divider to the OVP pin), the device immediately turns off the external P-channel FET, disconnecting the load from the abnormal voltage and thus preventing damage to any downstream components. Simultaneously, the fault flag is raised, alerting the system to a problem. If an over-voltage condition is applied at the time of the device enable, then the switch will remain OFF. The AAT4686 can also be used as a simple slew-rate controlled P-channel high side driver IC. Under-Voltage Lockout (UVLO) The AAT4686 has a fixed 3.0V under-voltage lockout level (UVLO). When the input voltage is less than the UVLO level, the MOSFET is turned off. 100mV of hyster- esis is included to ensure circuit stability. Functional Block Diagram Fixed Option OVP Sense and Control GND GATE FLT IN OVP EN

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Over-Voltage Protection The AAT4686 adjustable version has a 1.1V ± 1.5% over- voltage trip threshold on the OVP pin. With a resistor divider on OVP pin from IN to GND, the over-voltage trip point can be adjusted anywhere within the input voltage range (see Table 1). Once the over-voltage trip level is triggered, the external PMOS switch controller will shut off the PMOS in less than 1 μs. The AAT4686 fixed version is also available with the resistor divider internally integrated and the input volt- age trip point at 6.5V. The fixed version of the AAT4686 does not have a connection to the internal OVP circuitry and Pin 4 is designed to be not connected. FLT Output The FLT output is an active-low open-drain fault (OV) reporting output. A pull-up resistor should be connected from FLT to the logic I/O voltage of the host system. FLT will be asserted immediately if an over-voltage fault occurs (only about a 1μs inherited internal circuit delay). A 10ms blanking is applied to FLT signal prior to de- assertion. EN Input EN is an active-low enable input. EN is driven low, con- nected to ground, or left floating for normal device operation. Taking the EN high turns off the MOSFET. In the case of an over-voltage or UVLO condition toggling the EN will not override the fault condition and the switch will remain off. Device Operation On initial power-up, if V IN < UVLO or if V OVP > V OVP_TH (1.1V), the PMOS is held off. If UVLO < V IN, V OVP < VOVP_TH, and EN is low, the device enters startup after a 10ms internal delay.

Application Information

The AAT4686 over-voltage protection circuit provides fast protection against transient voltage spikes and short duration spikes of high voltage from the power supply lines. The AAT4686 can quickly disconnect the input supply from the load and not cause any damage to sen- sitive components. In portable product applications, if the user removes the battery pack during charging, this action can create large transients and a high voltage spike can occur which can damage other electronic devices in the prod- uct such as the battery charger. A hot plug of the AC/DC wall adapter into the AC outlet can create and release a voltage spike from the transformer. As a result, some sensitive devices within the product can be damaged. With the AAT4686 placed between the power lines and the sensitive devices, the voltage spike can be kept away and the input supply disconnected from other devices in 0.7μs. Figure 2 shows the response time of over-voltage pro- tection from the test circuit (Figure 1). The input volt- age is rapidly increased from 5V to 12V by a voltage surge or voltage spike. The voltage at the OVP pin is also increased until the trip point is triggered. At this point, the FLT pin is pulled low and the output voltage starts to fall. Figure 3 shows a zoom-in scope capture of the OVP response time; the output is disconnected from the input in as little as 700ns. Adjustable Version - Over-Voltage Protection Resistors The over-voltage protection threshold is programmed with two resistors, R1 and R2. To limit the current going through the external resistor string while maintaining good noise immunity, use smaller resistor values, such as 10KΩ for R2. Using a larger value will further reduce the system current, but will also increase the impedance of the OVP node, making it more sensitive to external noise and interference. A suggested value for R2 is 110KΩ. Table 1 summarizes resistor values for various over-voltage settings. Use 1% tolerance metal film resistors for programming the desired OVP setting.

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Input Capacitor A 1μF or larger capacitor is typically recommended for CIN. CIN 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 opera- tion, 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. Capacitors are typically manufactured in different volt- age ratings. 16V, 25V, and 50V are good for OVP applica- tions. If the maximum possible surge voltage is known, select capacitors with a voltage rating at least 5V higher than the maximum possible surge voltage. Otherwise, 50V rated capacitors are generally good for most OVP applications to prevent any surge voltage. Output Capacitor In order to insure stability while current limit is active, a small output capacitance of approximately 1 μF is required at the output. Likewise, with the output capac- itor, there is no specific capacitor ESR requirement. If desired, C OUT may be increased to accommodate any load transient condition. FAULT Flag A FAULT flag is provided to alert the system if the AAT4686’s input voltage has passed the pre-programmed over-voltage trip point. Since the FAULT is open drain pin, it should be pulled up to input/output voltage rail and less than the maximum operating voltage of 6.5V. Thermal Considerations and High Output Current Applications The AAT4686 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 must be taken into account. The following discussions will assume the load switch is mounted on a printed cir- cuit 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: PD(MAX) = TJ(MAX) -TA θJA Constants for the AAT4686 are maximum junction tem- perature (TJ(MAX) = 125°C) and package thermal resis- tance (θJA = 225°C/W). Worst-case conditions are calcu- lated at the maximum operating temperature, T A = 85°C. Typical conditions are calculated under normal ambient conditions where T A = 25°C. At T A = 85°C, PD(MAX) = 175mW. At TA = 25°C, PD(MAX) = 440mW. The maximum continuous output current for the AAT4686 is a function of the package power dissipation and the R DS 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. For maximum current, refer to the following equation: = IOUT(MAX) PD(MAX) RDS Printed Circuit Board Layout Recommendations For proper thermal management, certain circuit board layout rules should be followed: VIN and VOUT 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 AAT4686 SC70JW-8 package, the ground plane area con- nected 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; see Figures 4 and 5.

MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET AAT4686 MOSFET Driver IC with Over-Voltage ProtectionOVPSwitch TM PRODUCT DATASHEET Advanced Analogic Technologies, Inc.

3230 Scott Boulevard, Santa Clara, CA 95054

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 pr oduct. 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 specifi cations or to discontinue any product or service without notice. Except as provided in AnalogicTech’s terms and conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties relating to fi tness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specifi c testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.

Ordering Information

Package OVP Trip Voltage Marking 1 Part Number (Tape and Reel)2 SC70JW-8 Adjustable YAXYY AAT4686IJS-T1 SC70JW-8 6.5V AAT4686IJS-6.5-T1 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/about/quality.aspx.

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 measurements in millimeters. 1. XYY = assembly and date code. 2. Sample stock is generally held on part numbers listed in BOLD.