RT9701 100mΩ Ω Power Distribution Switches General Description Features The RT9701 is an integrated 100mΩ power switch for self-powered and bus-powered Universal Series Bus (USB) applications. A built-in charge pump is used to drive the N-Channel MOSFET that is free of parasitic z body diode to eliminate any reversed current flow across the switch when it is powered off. Its low quiescent current (23μA) and small package (SOT-23-5) is particularly suitable in battery-powered portable equipment. z Several protection functions include soft start to limit inrush current during plug-in, current limiting at 1.5A to meet USB power requirement, and thermal shutdown to protect damage under over current conditions. z z z z z z z z Applications z Ordering Information z z RT9701 z Package Type B : SOT-23-5 BL : SOT-23-5 (L-Type) Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) Note : RichTek Pb-free and Green products are : 100mΩ Ω Typ. High-Side NMOSFET (SOT-23-5) Guaranteed 1.1A Continuous Current 1.5A Current Limit Small SOT-23-5 Package Minimizes Board Space Soft Start Thermal Protection Low 23μ μA Supply Current Wide Input Voltage Range : 2.2V to 6V UL Approved - #E219878 RoHS Compliant and 100% Lead (Pb)-Free z Battery-Powered Equipment Motherboard USB Power Switch USB Device Power Switch Hot-Plug Power Supplies Battery-Charger Circuits Pin Configurations (TOP VIEW) VOUT 1 GND 2 VIN 3 5 VOUT VOUT 1 GND 2 VIN 3 5 VOUT 4 VIN `RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. 4 EN `Suitable for use in SnPb or Pb-free soldering processes. SOT-23-5 `100% matte tin (Sn) plating. Marking Information For marking information, contact our sales representative directly or through a RichTek distributor located in your area, otherwise visit our website for detail. SOT-23-5 (L-Type) Typical Application Circuit RT9701CBL VIN VOUT VIN CIN 1uF VIN VOUT GND VOUT * COUT 470uF * 470uF, Low ESR Electrolytic DS9701-13 March 2007 www.richtek.com 1 RT9701 Test Circuits VIN VOUT CL GND RL VIN IL VIN-SW Switch Off + CIN 1uF VIN + RL VOUT VOUT CL GND + EN CIN 1uF CL Test Circuit 2 IOUT RT9701CB VIN VOUT VOUT GND Test Circuit 1 VIN VOUT RT9701CBL VIN VOUT + VIN + + CIN 1uF VOUT IOUT RT9701CBL VIN VOUT RL IL Chip Enable Test Circuit 3 Test Circuit 2 is performed by charging an external tank of bulk capacitor to the input then applying this voltage to the input of the unit. All typical operating characteristics curves showed are referred to Test Circuit 1, unless specified to Test Circuit 2 or Test Circuit 3. Functional Pin Description Pin Name Pin Function VIN Power Input Voltage VOUT Output Voltage GND Ground EN Chip Enable (Active High) Function Block Diagram VIN EN Current Limit Bias Charge Pump Control NMOSFET RS (VIN) (VOUT) VOUT Oscillator www.richtek.com 2 Thermal Detection GND DS9701-13 March 2007 RT9701 Absolute Maximum Ratings z z z z z z z z Supply Voltage --------------------------------------------------------------------------------------------------------- 7V Chip Enable ------------------------------------------------------------------------------------------------------------- −0.3V to 7V Power Dissipation, PD @ TA = 25°C SOT-23-5 ---------------------------------------------------------------------------------------------------------------- 0.25W Package Thermal Resistance SOT-23-5, θJA ----------------------------------------------------------------------------------------------------------- 250°C /W Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C Operating Junction Temperature Range -------------------------------------------------------------------------- −20°C to 100°C Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C VOUT ESD Level HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 8kV MM (Machine Mode) -------------------------------------------------------------------------------------------------- 800V Electrical Characteristics (VIN = 5V, CIN = COUT = 1μF, TA = 25°C, unless otherwise specified) Parameter Symbol Input Voltage Range Output NMOSFET RDS(ON) Test Conditions Min Typ Max Units 2.2 -- 6 V IL = 1A -- 85 100 IL = 1A -- 87 100 VIN = 3V -- 19 40 VIN = 5V -- 23 45 -- 400 -- μs 1.1 1.5 2 A -- 1.0 -- A VIN RT9701CBL RT9701CB RDS(ON) Quiescent Current Output Turn-On Rising Time TR RL = 10Ω, 90% Settling Current Limit Threshold ILIMIT Short-circuit Fold Back Current IOS RL = 2Ω VOUT = 0V, measured prior to thermal shutdown mΩ μA EN Input High Threshold RT9701CB 2.0 -- -- V EN Input Low Threshold RT9701CB -- -- 0.8 V Shutdown Supply Current RT9701CB IOFF EN = “0” -- 0.1 1 μA Output Leakage Current RT9701CB ILEAKAGE EN = “0”, VOUT = 0V -- 0.5 10 μA 1.3 1.8 -- V -- 100 -- mV VIN Under Voltage Lockout UVLO VIN Under Voltage Hysteresis Thermal Limit TSD -- 130 -- °C Thermal Limit Hysteresis ΔTSD -- 20 -- °C DS9701-13 March 2007 www.richtek.com 3 RT9701 Typical Operating Characteristics Quiescent Current vs. Temperature Quiescent Current vs. Input Voltage 40 40 VIN = 5V TA = 25°C 35 Quiescent Current (uA) Quiescent Current ( uA) 35 30 25 20 15 10 5 30 25 20 15 10 5 0 0 -40 -20 0 20 40 60 80 100 120 2.0 2.5 3.0 Temperature (° C) 3.5 4.0 4.5 5.0 On-Resistance vs. Temperature 100 VIN = 5V 150 RT9701CBL 100 TA = 25°C On-Resistance (mΩ) On-Resistance (mΩ) 6.0 On-Resistance vs. Input Voltage 200 RT9701CB 50 95 90 RT9701CB 85 RT9701CBL 80 0 -40 -20 0 20 40 60 80 100 2.0 120 2.5 3.0 Temperature ((℃ ) ° C) 3.5 4.0 4.5 5.0 5.5 6.0 Input Voltage(V) Current Limit vs. Temperature Current Limit vs. Input Voltage 2.20 1.80 VIN = 5V 2.00 TA = 25°C 1.58 1.80 Current Limit (A) Current Limit (A) 5.5 Input Voltage (V) 1.60 1.40 1.20 1.00 0.80 1.35 1.13 0.90 0.68 0.45 0.23 0.60 0.00 -40 -20 0 20 40 60 Temperature (° C) www.richtek.com 4 80 100 120 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Input Voltage (V) DS9701-13 March 2007 RT9701 Short Circuit Current vs. Temperature Short Circuit Current vs. Input Voltage 1950 VIN = 5V 1300 TA = 25°C Short Circuit Current (mA) Short Circuit Current (mA)1 1400 1200 1100 1000 900 800 700 1700 1450 1200 600 950 700 450 200 500 -40 -20 0 20 40 60 80 100 2.0 120 2.5 3.0 3.5 4.0 4.5 5.0 Temperature ( C) ° C) EN Threshold Voltage vs. EN Pin Threshold vs. Temperature 2.4 VIN = 5V 2.0 1.6 Rising 1.2 TA = 25°C EN Pin (V) ENThreshold ThresholdVoltage (V) EN Pin Voltage ENThreshold Threshold (V) (V) 6.0 EN EN PinThreshold Thresholdvs. Voltage vs. Input Input Voltage 2.4 Falling 0.8 0.4 2.0 1.6 Rising 1.2 Falling 0.8 0.4 0.0 0.0 -40 -20 0 20 40 60 80 Temperature (° C) 100 2.0 120 2.5 3.0 3.5 4.0 4.5 5.0 Input Voltage (V) *Test Circuit 3 Turn On Rising Time vs. Temperature 5.5 6.0 *Test Circuit 3 Turn Off Falling Time vs. Temperature 140 720 VIN = 5V VIN = 5V 630 Turn-Off Falling Time (us) Turn-On Rising Time (us) 5.5 Input Voltage (V) 540 450 360 270 180 RL =30Ω 90 120 100 80 60 40 20 CL = 1uF Ceramic RL = 30Ω CL = 1uF Ceramic 0 0 -40 -20 0 20 40 60 Temperature (° C) DS9701-13 March 2007 80 100 120 *Test Circuit 3 -40 -20 0 20 40 60 Temperature (° C) 80 100 120 *Test Circuit 3 www.richtek.com 5 Shutdown Supply Current vs. Temperature Turn-Off Leakage Current vs. Temperature 0.9 3.5 VIN = 5V 0.8 0.6 0.5 0.3 0.2 Turn-Off Leakage Current (uA) A Shutdown Supply Current (uA) RT9701 VIN = 5V 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0.0 -40 -20 0 20 40 60 80 Temperature (° C) 100 120 -40 -20 0 20 40 60 80 Temperature (° C) *Test Circuit 3 UVLO Threshold vs. Temperature 100 120 *Test Circuit 3 Inrush Current Response 3.50 VIN = 5V UVLO Threshold (V) 3.00 2.50 CL = 100uF CL = 33uF 2.00 1.50 CL = 1uF 1.00 0.50 IL = 1A/Div, RL = 1Ω, VIN = 5V 0.00 -40 -20 0 20 40 60 80 100 120 Time (100us/Div) Temperature (° C) Turn - On Response Turn - Off Response CH1 CH1 CH2 CH1: VEN: 5V/Div CH2: IOUT: 100mA/Div CH3: VOUT: 2V/Div CH2 CH1: VEN: 5V/Div CH2: VOUT: 1V/Div RL = 30Ω, CL = 1uF Time (100us/Div) www.richtek.com 6 *Test Circuit 3 CH3 RL = 30Ω, CL = 1uF Time (50us/Div) *Test Circuit 3 DS9701-13 March 2007 RT9701 UVLO at Rising UVLO at Falling CH1 CH2 CH1 CH1: VIN: 1V/Div CH2: VOUT: 1V/Div RL = 30Ω, CL = 1uF CH2 CH1: VIN: 1V/Div CH2: VOUT: 1V/ Div RL = 30Ω, CL = 1uF Time (100ms/Div) Time (500us/Div) Inrush Short Circuit Response *Test Circuit 2 Soft - start Short Circuit Response CH1: VIN: 2V/Div CH1: VIN: 2V/Div VDROP=1.2V, depend on CIN ESR IPEAK : depend on ESR & ESL CH1 CH1 CH2: IOUT: 1A/Div CH2 CIN = 1uF, CL = 1000uF CH2: IL: 10A/Div CH2 CIN = 1uF Time (5us/Div) Time (25us/Div) Ramped Load Response CH1 Current Limit Response VOUT = 4.6V VOUT= 5V 4.9V CH1 Loading trigger Current Limit Threshold 1.1V CH2 CH2 CH2: IOUT: 500mA/Div Time (1ms/Div) DS9701-13 March 2007 VIN = 5V, CL = 1uF CH2: IOUT: 1A/Div VIN = 5V, CL = 0.1uF RL = 1Ω Time (5us/Div) www.richtek.com 7 RT9701 Thermal Shut Response Dowm CH1 CH3 Thermal Shut Down CH2 CH1: VEN = 5V/Div, CH3: IOUT@RL1Ω: 1A/Div CH2: IOUT@short: 1A/DiV, VIN = 5V Time (50ms/Div) Current Limiting and Short Protection The current limit circuit is designed to protect the system supply, the MOSFET switch and the load from damage caused by excessive currents. The current limit threshold is set internally to allow a minimum of 1.1A through the MOSFET but limits the output current to approximately 1.5A typical. When the output is short to ground, it will limit to a constant current 1A until thermal shutdown or short condition removed. RT9701CBL VIN VOUT VIN VIN CIN 1uF VOUT GND COUT Application Information Thermal shutdown shuts off the output MOSFET if the die temperature exceeds 130°C and 20°C of hysteresis forces the switch turning off until the die temperature drops to 110°C. Soft Start In order to eliminate the upstream voltage droop caused by the large inrush current during hot-plug events, the “ soft-start” feature effectively isolates power supplies from such highly capacitive loads. Under-voltage Lockout UVLO prevents the MOSFET switch from turning on until input voltage exceeds 1.8V (typical). If input voltage drops below 1.8V (typical), UVLO shuts off the MOSFET switch. www.richtek.com 8 COUT CIN = 10uF, COUT = 1uF on USB device Figure 1. High Side Power Switch Input and Output Thermal Shutdown VOUT2 CIN = 1uF, COUT = 470uF (Low ESR) on M/B CIN = 1uF, COUT = 330uF (Low ESR) on Notebook The RT9701 is a high-side single N-Channel MOSFET switch with active-high enable input. VIN (input) is the power supply connection to the circuitry and the drain of the output MOSFET. VOUT (output) is the source of the output MOSFET. In a typical circuit, current flows through the switch from VIN to VOUT toward the load. Both VOUT pins must be short on the board and connected to the load and so do both VIN pins but connected to the power source. VOUT1 VIN CIN VIN RT9701CB VOUT EN VOUT GND Chip Enable VOUT1 COUT VOUT2 COUT Figure 2. High Side Power Switch with Chip Enable Control Filtering To limit the input voltage drop during hot-plug events, connect a 1μF ceramic capacitor from VIN to GND. However, higher capacitor values will further reduce the voltage drop at the input. Connect a sufficient capacitor from VOUT to GND. This capacitor helps to prevent inductive parasitics from pulling VOUT negative during turn-off or EMI damage to other components during the hot-detachment. It is also necessary for meeting the USB specification during hot plug-in operation. If RT9701 is implanted in device end application, minimum 1μF capacitor from VOUT to GND is recommended and higher capacitor values are also preferred. DS9701-13 March 2007 RT9701 In choosing these capacitors, special attention must be paid to the Effective Series Resistance, ESR, of the capacitors to minimize the IR drop across the capacitor ESR. A lower ESR on this capacitor can get a lower IR drop during the operation. Ferrite beads in series with all power and ground lines are recommended to eliminate or significantly reduce EMI. In selecting a ferrite bead, the DC resistance of the wire used must be kept to a minimum to reduce the voltage drop. Reverse current preventing The output MOSFET and driver circuitry are also designed to allow the MOSFET source to be externally forced to a higher voltage than the drain (VOUT > VIN ≥ 0). To prevent reverse current from such condition, disable the switch (RT9701CB) or connect VIN to a fixed voltage under 1.3V. Layout and Thermal Dissipation z z z z z Place the switch as close to the USB connector as possible. Keep all traces as short as possible to reduce the effect of undesirable parasitic inductance. Place the ot capacitor and ferrite beads asclose to the USB connector as possible. If ferrite beads are used, use wires with minimum resistance and large solder pads to minimize connection resistance. If the package is with dual VOUT or VIN pins, short both the same function pins as Figure 1 or Figure 2 to reduce the internal turn-on resistance. If the output power will be delivered to two individual ports, it is specially necessary to short both VOUT pin at the switch output side in order to protect the switch when each port are plug-in separately. Under normal operating conditions, the package can dissipate the channel heat away. Wide power-bus planes connected to VIN and VOUT and a ground plane in contact with the device will help dissipate additional heat. DS9701-13 March 2007 www.richtek.com 9 RT9701 Outline Dimension H D L B C b A A1 e Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.889 1.295 0.035 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.356 0.559 0.014 0.022 C 2.591 2.997 0.102 0.118 D 2.692 3.099 0.106 0.122 e 0.838 1.041 0.033 0.041 H 0.080 0.254 0.003 0.010 L 0.300 0.610 0.012 0.024 SOT-23-5 Surface Mount Package Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)89191466 Fax: (8862)89191465 Email: [email protected] www.richtek.com 10 DS9701-13 March 2007