AOZ1300 Programmable 4A Power Distribution Switch General Description Features The AOZ1300 is a current-limited power distribution switch intended for applications that require circuit protection. The device operates from a 2.7V to 6.0V input supply and provides up to 4A load current. AOZ1300 offers robust fault protection features including over-current/short-circuit protection and thermal overload protection. The current limit is programmable with an external resistor. An open-drain fault indicator is provided to alert a system controller of thermal overload, overcurrent, and short-circuit events. A 24ms fault blanking time eliminates false alarms. ● The AOZ1300 employs internal soft-start circuitry to control inrush current due to highly capacitive loads associated with hot-plug events. An adjustable slew rate control pin provides additional slew rate control if needed. ● ● ● ● ● ● ● ● ● Open-drain fault indicator 1µA shutdown current Applications ● ● The AOZ1300 is available in SO-8 package. 40mΩ maximum on-resistance 4A maximum continuous current 2.7V to 6.0V operating voltage Resistor programmable current limit Reverse current blocking Thermal overload protection Very fast short-circuit response time Fault latch with 24ms blanking time ● ● ● ● Docking stations Notebook PCs RAID systems Telecom and Server hot-plug USB Power Distribution Compact PCI adapter Cards Typical Application VOUT VIN OUT IN C1 1µF C2 4.7µF R1 100kΩ TO USB PORT AOZ1300 FLT FAULT OFF ON GND EN SLEW C3 10nF ISET R2 10kΩ Figure 1. High Current USB Host Rev. 1.3 August 2008 www.aosmd.com Page 1 of 12 AOZ1300 Ordering Information Part Number Temperature Range Package Environmental AOZ1300AI -40°C to +85°C SO-8 RoHS Compliant AOZ1300AIL -40°C to +85°C SO-8 Green Product • All AOS products are offered in packages with Pb-free plating and compliant to RoHS standards. • Parts marked as Green Products (with “L” suffix) use reduced levels of Halogens, and are also RoHS compliant. Please visit www.aosmd.com/web/quality/rohs_compliant.jsp for additional information. Pin Configuration IN 1 8 OUT SLEW 2 7 IC GND 3 6 FLT ISET 4 5 EN SO-8 (Top View) Pin Description Pin Number Pin Name Pin Function 1 IN Switch Power Input. IN also supplies power to internal circuitry. 2 SLEW Slew Rate Control Pin. Leaving this pin open results in a minimum output slew rate. Connect a capacitor from SLEW to GND to increase output slew rate. 3 GND Ground. 4 ISET Current-Limit Setting Pin. Connect a resistor from ISET to GND to set the currentlimit. 5 EN Enable Input. Pull EN high to enable the device. The part enters into low-power shutdown when EN is pulled low. 6 FLT Fault Indicator. FLT is an open-drain output. FLT is asserted low during over-current or thermal overload events. FLT is asserted after the fault blanking period. 7 IC Internally Connected Pin. No external connection is allowed to this pin. Leave this pin floating. 8 OUT Switch Output Pin. Rev. 1.3 August 2008 www.aosmd.com Page 2 of 12 AOZ1300 Absolute Maximum Ratings Recommend Operating Ratings Exceeding the Absolute Maximum ratings may damage the device. The device is not guaranteed to operate beyond the Maximum Operating Ratings. Parameter IN, OUT, EN, FLT, ISET, SLEW to GND Parameter Rating Rating 6.5V Input Supply Voltage (VIN) +2.7V to +6.0V OUT Maximum Continuous Current 5A Ambient Temperature -40°C to +85°C Junction Temperature (TJ) +150°C SO-8 Thermal Resistance (ΘJA)(1) 87°C/W Storage Temperature (TS) -65°C to +150°C Note: 1.The package ΘJA is measured with the device mounted on 1-in2 FR-4 printed-circuit board with 2-oz. copper in a still air environment with TA = 25°C. The value may vary depending on user’s specific board design. Electrical Characteristics VIN = 5V, TA = -40°C to +85°C unless otherwise stated. Typical values are at 25°C. Parameter Symbol Conditions VIN Supply Voltage IIN Supply Current Switch on, no load Switch off, no load VUV Undervoltage Lockout Threshold VIN rising VUVHYS Undervoltage Lockout Hysteresis VEN VENHYS Enable Input Voltage Min. Typ. Max. Units 6.0 V 380 1 530 2 mA 2.3 2.68 V 2.7 1.9 300 Enable Input Low Voltage Enable Input High Voltage mV 0.8 Enable Input Voltage Hysteresis 400 IEN Enable Input Current VIN = 4.5V RDS(ON) Switch On Resistance VIN = 4.5V VIN = 2.5V ILIM Short-circuit Current RSET =76.8kΩ, TA = +25°C to +85°C IOFF Output Leakage Current VOL FLT Output Voltage V 2.0 mV 1 µA 35 48 45 60 mΩ 4.0 4.8 A Switch Off 1 µA IOL = 5mA 0.4 V 3.2 FLT Output Leakage Current tFLT FLT Timeout Period ILIM to FLT assertion, TA = +25°C to +85°C tON Output Turn-on Delay RL = 10Ω, CL = 1µF 18 24 1 µA 30 ms 750 µs Output Turn-off Delay RL = 10Ω, CL = 1µF 43 µs tr Output Rise-time RL = 10Ω, CL = 1µF 460 µs tf Output Fall-time RL = 10Ω, CL = 1µF 15 µs tOFF Rev. 1.3 August 2008 www.aosmd.com Page 3 of 12 AOZ1300 Typical Performance Characteristics Supply Current vs. Temperature Enable Input Threshold (Falling) vs. Temperature 1.60 5.5V 450 1.50 400 1.40 350 1.30 Ven (V) Supply Current (µA) 500 300 250 3.6V 200 1.10 2.5V 2.5V -20 0.90 0 20 40 60 Temperature (°C) 80 0.80 -40 100 Enable Input Threshold (Rising) vs. Temperature 2.00 1.90 1.80 1.70 1.60 1.50 1.40 1.30 1.20 1.10 1.00 -20 0 100 3.6V 2.5V 50 40 30 2.5V, 3.6V, 5.5V 20 10 0 -20 0 20 40 60 80 100 -40 -20 0 Temperature (C) On Resistance (mΩ) UVLO+ 2.25 2.20 2.15 2.10 UVLO- 2.05 100 -20 0 20 40 60 Temperature (°C) 80 60 55 2.5V 50 45 3.6V 40 35 5.5V 30 25 20 100 -40 26 1.40 Turn-On Delay (µS) 1.50 25 3.6V 24 5.0V 5.5V 23 -20 0 20 40 60 Temperature (°C) 80 100 80 100 Turn-On Delay vs. Temperature Fault Delay vs. Temperature 27 22 21 20 -40 80 65 2.30 2.00 -40 20 40 60 Temperature (C) On Resistenace vs. Temperature UVLO Threshold vs. Temperature 2.35 UVLO (V) 80 Output Leakage Current vs. Temperature 5.5V -40 Fault Delay (ms) 20 40 60 Temperature (°C) 60 Output Leakage (nA) Ven (V) 3.6V 1.20 1.00 150 100 -40 5.5V 1.30 2.5V 1.20 1.10 3.6V 1.00 0.90 5.5V 0.80 -20 Rev. 1.3 August 2008 0 20 40 60 Temperature (°C) 80 100 0.70 -40 www.aosmd.com -20 0 20 40 60 Temperature (°C) Page 4 of 12 AOZ1300 Turn-On Turn-Off EN 5V/div EN 5V/div VOUT 2V/div VOUT 2V/div I OUT 1A/div I OUT 1A/div Time (1ms/div.) Time (200µs/div.) Output Slew Rate Control Short Circuit Response EN 5V/div VOUT 5V/div FLT 5V/div FLT 5V/div I OUT 1A/div VOUT 2V/div I OUT 1A/div Time (4ms/div.) Time (4ms/div.) Latched Output UVLO Response EN 5V/div VIN 5V/div FLT 5V/div VOUT 5V/div VOUT 5V/div I OUT 5A/div Time (4ms/div.) Rev. 1.3 August 2008 Time (20ms/div.) www.aosmd.com Page 5 of 12 AOZ1300 Timing Diagrams 50% 50% EN 90% 10% VOUT t ON t OFF Active-High Enable ILIM IOUT FLT t FLT Over-current Fault Output Response Functional Block Diagram IN OUT Switch Charge Pump Gate Driver & Slew Rate Control SLEW Current Limit ISET 2.3V UVLO Comparator Thermal Shutdown EN FLT Fault Delay & Latch Rev. 1.3 August 2008 www.aosmd.com Page 6 of 12 AOZ1300 Detailed Description The AOZ1300 is a high-side, current-limited, N-channel MOSFET switch optimized for power distribution applications which require circuit protection. The device operates from 2.7V to 6.0V input voltage and offers current limiting and thermal overload protection. The device can be programmed for load current up to 4A using a single resistor. An open-drain fault output is provided to indicate over-current and thermal overload fault conditions. The AOZ1300’s soft-start circuitry minimizes the inrush current in applications that employ highly capacitive loads. The output slew-rate may be increased with an external capacitor if longer soft-start time is desired. The AOZ1300 features a circuit breaker mode that latches the output off upon detecting an overcurrent condition lasting more than 24ms or detecting a thermal overload condition. The AOZ1300 features reverse current blocking function. Therefore, the output voltage can be higher than the input voltage. output shuts off, it remains off until the fault load is removed from output and the EN input is toggled or the input power is recycled. If the fault is still present after EN has been cycled, the AOZ1300 will again shut off all power to the load after 24ms. Enable The FLT pin is an open drain output that is asserted low when either an over-current, short-circuit or thermal overload condition occurs. To prevent false alarm, the AOZ1300 implements a 24ms fault blanking time for over-current and short-circuit fault conditions. The FLT pin becomes high impedance when the fault conditions are removed. A 100kΩ pull-up resistor must be connected between FLT to VIN to provide a logic signal. The EN pin is the ON/OFF control for the output switch. It is an active-high input. The EN pin is active after VIN is above the UVLO threshold of 2.3V. Conversely, the Enable will be de-activated if the VIN falls below the UVLO of 2.0V. The EN pin must be driven to a logic high or logic low state to guarantee operation. While disabled, the AOZ1300 only draws about 1µA supply current. The EN is a high impedance input with an ESD protection diode to ground and should not be forced below ground. This input level is compatible with most microcontroller outputs and other logic families. Under-Voltage Lockout (UVLO) The under-voltage lockout (UVLO) circuit of AOZ1300 monitors the input voltage and prevents the output MOSFET from turning on until VIN exceeds 2.3V. The AOZ1300 will trigger a fault condition and shut down the device when VIN falls below 2.0V. Over-Current and Short-Circuit Protection The AOZ1300 is designed to shut off all power to the load when the output current exceeds the limit for more than the fault blanking period. In the event of an output short circuit the current through the switch is limited by an internal current-limiting amplifier. The current-limit circuit employs a current- sensing algorithm that uses the on-state resistance of the high-side MOSFET as a current-sensing element. If the current-sense voltage is above the current-limit threshold, the AOZ1300 will turn off the internal MOSFET. The AOZ1300 has a very fast short-circuit response time, nominally 25µs. Once the Rev. 1.3 August 2008 Thermal Overload Protection The thermal overload protection of AOZ1300 is engaged to protect the device from damage should the die temperature exceeds safe margins due to a short circuit, extreme loading or heating from external sources. Thermal overload protection sets a fault latch and shuts off the internal MOSFET and asserts the FLT output if the junction temperature exceeds +120°C. The AOZ1300 can be re-enabled by toggling EN pin or cycling the input supply after the die temperature drops below +110°C. Fault Indicator Slew Rate Control The output voltage rise time is controlled to a minimum of 400µs and is controlled by an internal slew-rate limiting circuit. The slew-rate can be increased by placing a capacitor between SLEW and ground. As a result, longer rise times can be achieved for specific applications. The slew rate is independent from the load. Please see Slew Rate Setting section for detailed information. Applications Information Input and Output Capacitor Selection The input capacitor prevents large voltage transients from appearing at the input, and provides the instantaneous current needed each time the switch turns on and to limit input voltage droop. Also it is to prevent high-frequency noise on the power line from passing through the output of the power side. The choice of the input capacitor is based on its ripple current and voltage ratings rather than its capacitor value. The input capacitor should be a low ESR type and located as close to the VIN pin as possible. A 0.1µF 6.3V ceramic cap is recommended. However, higher capacitor values further reduce the voltage drop at the input. www.aosmd.com Page 7 of 12 AOZ1300 The output capacitor acts in a similar way. A small 0.1µF capacitor prevents high-frequency noise from going into the system. Also, the output capacitor has to supply enough current for a large load that it may encounter during system transients. This bulk capacitor must be large enough to supply fast transient load in order to prevent the output from dropping. Current Limit Setting The AOZ1300 features internal current-limiting circuitry with a maximum programmable value of 4.0A. This current limit remains in effect throughout the input supply-voltage range. The current limit is program by using external resistor connected to the ISET pin. The current-limit adjustment resistor range is from 70kΩ to 600kΩ. 600 500 500 400 400 Rset (kΩ) Rset (kΩ) Current Limit vs. Rset @ 5.5V 600 300 300 200 200 100 100 0 0.5 1.0 1.5 2.0 2.5 3.0 Current Limit (A) 3.5 4.0 Current Limit vs. Rset @ 3.6V 0 0.5 1.0 1.5 2.0 2.5 3.0 Current Limit (A) 3.5 4.0 Current Limit vs. Rset @ 2.5V 600 Rset (kΩ) 500 400 300 200 100 0 0.5 1.0 1.5 2.0 2.5 3.0 Current Limit (A) Slew Rate Setting Slew rate is set by changing the capacitor value on the Slew pin of the device. A capacitor connected between this pin and ground will reduce the output slew-rate. The 3.5 4.0 capacitor requires a 6.3V rating or greater. The capacitive range is 0.001µF to 0.1µF. Please see graph for Output Slew Rate Adjustment vs. Capacitance. 4.00 70.000 3.50 60.000 3.00 5.5V 50.000 3.6V 40.000 2.5V 30.000 20.000 Output Slew Rate Adjustment 5.5V 2.50 3.6V 2.00 1.50 2.5V 1.00 0.50 10.000 0.000 0 Slew Rate (mS) Slew Rate (mS) Output Slew Rate Adjustment 80.000 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 Capacitance (µF) Rev. 1.3 August 2008 www.aosmd.com 0 1 2 3 Capacitance (nF) 4 5 Page 8 of 12 AOZ1300 Power Dissipation Calculation Calculate the power dissipation for normal load condition using the following equation: PD = RON x (IOUT)2 The worst case power dissipation occurs when the load current hits the current limit due to over-current or short circuit faults. The power dissipation under these conditions can be calculated using the following equation: PD = (VIN – VOUT) x ILIMIT PCB Layout Guidelines Proximity of passive devices and adequate power and ground planes are critical for reliable operation of the circuit. In general, use the top layer for the high current connections and the bottom or inner layer for the quiet connections such as GND. The power traces must be as short and wide as possible, because of large current. Long metal traces and component leads may cause unwanted parasitic inductance and capacitance. In order to achieve the best performance special care has to be taken for proper grounding. A good practice is always the use of a separate ground plane or at least a single point ground structure. It is recommended to use a PCB with at least two sides. It is very important to place the input and output capacitor as close as possible to the pin of the device. Silk Screen Top Top Layer Bottom Layer Rev. 1.3 August 2008 www.aosmd.com Page 9 of 12 AOZ1300 Package Dimensions, SO-8L D Gauge Plane Seating Plane e 0.25 8 L E E1 h x 45° 1 C θ 7° (4x) A2 A 0.1 b A1 Dimensions in millimeters 2.20 5.74 1.27 0.80 Unit: mm Symbols A A1 A2 b c D E1 e E h L θ Min. 1.35 0.10 1.25 0.31 0.17 4.80 3.80 Nom. 1.65 — 1.50 — — 4.90 3.90 1.27 BSC 5.80 6.00 0.25 — 0.40 — 0° — Max. 1.75 0.25 1.65 0.51 0.25 5.00 4.00 6.20 0.50 1.27 8° Dimensions in inches Symbols A A1 A2 b c D E1 e E h L θ Min. 0.053 0.004 0.049 0.012 0.007 0.189 0.150 Nom. Max. 0.065 0.069 — 0.010 0.059 0.065 — 0.020 — 0.010 0.193 0.197 0.154 0.157 0.050 BSC 0.228 0.236 0.244 0.010 — 0.020 0.016 — 0.050 0° — 8° Notes: 1. All dimensions are in millimeters. 2. Dimensions are inclusive of plating 3. Package body sizes exclude mold flash and gate burrs. Mold flash at the non-lead sides should be less than 6 mils. 4. Dimension L is measured in gauge plane. 5. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. Rev. 1.3 August 2008 www.aosmd.com Page 10 of 12 AOZ1300 Tape and Reel Dimensions, SO-8L SO-8 Carrier Tape P1 D1 See Note 3 P2 T See Note 5 E1 E2 E See Note 3 B0 K0 A0 D0 P0 Feeding Direction Unit: mm Package SO-8 (12mm) A0 6.40 ±0.10 B0 5.20 ±0.10 K0 2.10 ±0.10 D0 1.60 ±0.10 D1 1.50 ±0.10 E 12.00 ±0.10 SO-8 Reel E1 1.75 ±0.10 E2 5.50 ±0.10 P0 8.00 ±0.10 P2 2.00 ±0.10 P1 4.00 ±0.10 T 0.25 ±0.10 W1 S G N M K V R H W W N Tape Size Reel Size M 12mm ø330 ø330.00 ø97.00 13.00 ±0.10 ±0.30 ±0.50 W1 17.40 ±1.00 K H 10.60 ø13.00 +0.50/-0.20 S 2.00 ±0.50 G — R — V — SO-8 Tape Leader/Trailer & Orientation Trailer Tape 300mm min. or 75 empty pockets Rev. 1.3 August 2008 Components Tape Orientation in Pocket www.aosmd.com Leader Tape 500mm min. or 125 empty pockets Page 11 of 12 AOZ1300 Package Marking Z1300AI Part Number Code Underscore Denotes Green Product FAYWLT Assembly Lot Code Fab & Assembly Location Year & Week Code Rev. 1.3 August 2008 www.aosmd.com Page 12 of 12