RT9701

RT9701 100mΩ Power Distribution Switches General Description 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 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. 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. Features 100mΩ 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 23μA Supply Current Wide Input Voltage Range : 2.2V to 6V UL Approved - #E219878 RoHS Compliant and 100% Lead (Pb)-Free Applications Battery-Powered Equipment Motherboard USB Power Switch USB Device Power Switch Hot-Plug Power Supplies Battery-Charger Circuits Ordering Information RT9701 P ackage 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) Pin Configurations (TOP VIEW) VOUT GND VIN 1 2 3 4 EN 5 VOUT VOUT GND VIN 1 2 3 4 VIN 5 VOUT Note : RichTek Pb-free and Green products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. 100% matte tin (Sn) plating. SOT-23-5 SOT-23-5 (L-Type) 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. Typical Application Circuit VIN CIN 1uF RT9701CBL VIN VOUT VIN GND VOUT VOUT * COUT 470uF * 470uF, Low ESR Electrolytic DS9701-13 March 2007 www.richtek.com 1 RT9701 Test Circuits VIN + RT9701CBL VIN VOUT VIN GND VOUT IOUT + VOUT VIN VIN-SW RT9701CBL VIN VOUT + VIN GND VOUT + VOUT CIN 1uF CL RL IL Switch Off CIN 1uF CL RL Test Circuit 1 VIN + CIN 1uF VOUT Test Circuit 2 RT9701CB VIN VOUT EN GND VOUT IOUT + CL 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 VIN VOUT GND EN Pin Function Power Input Voltage Output Voltage Ground Chip Enable (Active High) Function Block Diagram EN Bias Current Limit RS VIN (VIN) Charge Pump Control NMOSFET (VOUT) VOUT Oscillator Thermal Detection GND www.richtek.com 2 DS9701-13 March 2007 RT9701 Absolute Maximum Ratings 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 Input Voltage Range Output NMOSFET RDS(ON) Quiescent Current Output Turn-On Rising Time Current Limit Threshold Short-circuit Fold Back Current EN Input High Threshold EN Input Low Threshold Shutdown Supply Current Output Leakage Current VIN Under Voltage Lockout VIN Under Voltage Hysteresis Thermal Limit Thermal Limit Hysteresis RT9701CB RT9701CB RT9701CB RT9701CB RT9701CBL RT9701CB Symbol VIN RDS(ON) Test Conditions Min 2.2 Typ -85 87 19 23 400 1.5 1.0 --0.1 0.5 1.8 100 130 20 Max 6 100 100 40 45 -2 --0.8 1 10 ----- Units V mΩ μA μs A A V V μA μA V mV °C °C IL = 1A IL = 1A VIN = 3V VIN = 5V -----1.1 -2.0 -- TR ILIMIT IOS RL = 10Ω, 90% Settling RL = 2Ω VOUT = 0V, measured prior to thermal shutdown IOFF UVLO EN = “0” --1.3 ---- ILEAKAGE EN = “0”, VOUT = 0V TSD ΔTSD DS9701-13 March 2007 www.richtek.com 3 RT9701 Typical Operating Characteristics Quiescent Current vs. Temperature 40 Quiescent Current vs. Input Voltage 40 VIN = 5V 35 TA = 25°C 35 Quiescent Current ( uA) 30 25 20 15 10 5 0 -40 -20 0 20 40 60 80 100 120 Quiescent Current (uA) 30 25 20 15 10 5 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Temperature (° C) Input Voltage (V) On-Resistance vs. Temperature 200 100 On-Resistance vs. Input Voltage TA = 25°C 95 VIN = 5V 150 On-Resistance (mΩ) 100 On-Resistance (mΩ) RT9701CBL RT9701CB 90 RT9701CB 85 50 RT9701CBL 80 0 -40 -20 0 20 40 60 80 100 120 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Temperature (℃) (° C) Input Voltage(V) Current Limit vs. Temperature 2.20 2.00 1.80 Current Limit vs. Input Voltage 1.58 VIN = 5V 1.35 1.13 0.90 0.68 0.45 0.23 0.00 TA = 25°C Current Limit (A) 1.80 1.60 1.40 1.20 1.00 0.80 0.60 -40 -20 0 20 40 60 80 100 120 Current Limit (A) 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Temperature (° C) Input Voltage (V) www.richtek.com 4 DS9701-13 March 2007 RT9701 Short Circuit Current vs. Temperature 1400 1950 Short Circuit Current vs. Input Voltage TA = 25°C 1700 1450 1200 950 700 450 200 Short Circuit Current (mA)1 1200 1100 1000 900 800 700 600 500 -40 -20 0 20 40 60 80 100 120 Short Circuit Current (mA) 1300 VIN = 5V 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Temperature (　C) ° C) Input Voltage (V) EN Pin Threshold Temperature EN Threshold vs. Voltage vs. 2.4 EN EN Threshold vs. Input Voltage Pin Threshold Voltage vs. Input 2.4 VIN = 5V TA = 25°C EN Pin Threshold Voltage (V) EN Threshold (V) 2.0 1.6 EN Pin Threshold Voltage (V) EN Threshold (V) 2.0 1.6 1.2 0.8 0.4 0.0 Rising Rising 1.2 0.8 0.4 0.0 -40 -20 0 20 40 60 80 100 120 Falling Falling 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Temperature (° C) *Test Circuit 3 Input Voltage (V) *Test Circuit 3 Turn On Rising Time vs. Temperature 720 140 Turn Off Falling Time vs. Temperature VIN = 5V 120 100 80 60 40 20 0 Turn-On Rising Time (us) 540 450 360 270 180 90 0 -40 -20 0 20 40 60 80 100 120 Turn-Off Falling Time (us) 630 VIN = 5V RL =30Ω CL = 1uF Ceramic RL = 30Ω CL = 1uF Ceramic -40 -20 0 20 40 60 80 100 120 Temperature (° C) *Test Circuit 3 Temperature (° C) *Test Circuit 3 DS9701-13 March 2007 www.richtek.com 5 RT9701 Shutdown Supply Current vs. Temperature 0.9 Turn-Off Leakage Current vs. Temperature Turn-Off Leakage Current (uA) A 3.5 Shutdown Supply Current (uA) VIN = 5V 0.8 0.6 0.5 0.3 0.2 0.0 -40 -20 0 20 40 60 80 100 120 VIN = 5V 3.0 2.5 2.0 1.5 1.0 0.5 0.0 -40 -20 0 20 40 60 80 100 120 Temperature (° C) *Test Circuit 3 Temperature (° C) *Test Circuit 3 UVLO Threshold vs. Temperature 3.50 Inrush Current Response VIN = 5V 3.00 UVLO Threshold (V) 2.50 2.00 1.50 1.00 0.50 CL = 100uF CL = 33uF CL = 1uF IL = 1A/Div, RL = 1Ω, VIN = 5V 0.00 -40 -20 0 20 40 60 80 100 120 Temperature (° C) Time (100us/Div) Turn - On Response Turn - Off Response CH1 CH1 CH2 CH1: VEN: 5V/Div CH2: IOUT: 100mA/Div CH2 CH1: VEN: 5V/Div CH2: VOUT: 1V/Div RL = 30Ω, CL = 1uF *Test Circuit 3 CH3: VOUT: 2V/Div CH3 RL = 30Ω, CL = 1uF Time (100us/Div) Time (50us/Div) *Test Circuit 3 www.richtek.com 6 DS9701-13 March 2007 RT9701 UVLO at Rising CH1 CH2 UVLO at Falling CH1 CH1: VIN: 1V/Div CH2: VOUT: 1V/Div RL = 30Ω, CL = 1uF CH1: VIN: 1V/Div CH2: VOUT: 1V/ Div RL = 30Ω, CL = 1uF CH2 Time (500us/Div) Time (100ms/Div) *Test Circuit 2 Inrush Short Circuit Response CH1: VIN: 2V/Div Soft - start Short Circuit Response CH1: VIN: 2V/Div VDROP=1.2V, depend on CIN ESR IPEAK : depend on ESR & ESL CH1 CH1 CH2: IOUT: 1A/Div CH2 CH2: IL: 10A/Div CIN = 1uF, CL = 1000uF CH2 CIN = 1uF Time (25us/Div) Time (5us/Div) Ramped Load Response CH1 VOUT = 4.6V VOUT= 5V 4.9V Current Limit Response CH1 Loading trigger Current Limit Threshold 1.1V CH2 CH2 CH2: IOUT: 500mA/Div VIN = 5V, CL = 1uF CH2: IOUT: 1A/Div VIN = 5V, CL = 0.1uF RL = 1Ω Time (1ms/Div) Time (5us/Div) DS9701-13 March 2007 www.richtek.com 7 RT9701 Thermal Shut Response CH1 Dowm 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. VIN CIN 1uF RT9701CBL VIN VOUT VIN GND COUT VOUT VOUT1 VOUT2 COUT CH3 Thermal Shut Down CH2 CH1: VEN = 5V/Div, CH3: IOUT@RL1Ω: 1A/Div CH2: IOUT@short: 1A/DiV, VIN = 5V Time (50ms/Div) Application Information The RT9701 is a high-side single N-Channel MOSFET switch with active-high enable input. Input and Output 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. Thermal Shutdown 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. CIN = 1uF, COUT = 470uF (Low ESR) on M/B CIN = 1uF, COUT = 330uF (Low ESR) on Notebook CIN = 10uF, COUT = 1uF on USB device Figure 1. High Side Power Switch VIN CIN VIN EN RT9701CB VOUT VOUT GND VOUT1 COUT VOUT2 COUT Chip Enable 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. www.richtek.com 8 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 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 C B b A A1 e Symbol A A1 B b C D e H L Dimensions In Millimeters Min 0.889 0.000 1.397 0.356 2.591 2.692 0.838 0.080 0.300 Max 1.295 0.152 1.803 0.559 2.997 3.099 1.041 0.254 0.610 Dimensions In Inches Min 0.035 0.000 0.055 0.014 0.102 0.106 0.033 0.003 0.012 Max 0.051 0.006 0.071 0.022 0.118 0.122 0.041 0.010 0.024 SOT-23-5 Surface Mount Package Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Richtek Technology Corporation Taipei Office (Marketing) 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com www.richtek.com 10 DS9701-13 March 2007