RT9701BGBL

Preliminary RT9701B 100mΩ Power Distribution Switches General Description The RT9701B 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 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 : 3.5V 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 RT9701B 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) Pin Configurations (TOP VIEW) 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. VOUT GND VIN 1 2 3 5 VOUT VOUT GND 1 2 3 5 VOUT 4 EN VIN 4 VIN 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 VIN VIN GND RT9701B VOUT VOUT VOUT * COUT 470uF * 470uF, Low ESR Electrolytic DS9701B-04 March 2007 www.richtek.com 1 RT9701B Test Circuits VIN + CIN 1uF Preliminary VIN_SW IIN RT9701B VIN VOUT EN GND VOUT IOUT + IL VOUT COUT RL IL Chip Enable 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 DS9701B-04 March 2007 Preliminary Absolute Maximum Ratings (Note 1) RT9701B 7V Supply Voltage ------------------------------------------------------------------------------------------------------------Chip Enable ----------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C SOT-23-5 -------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 3) SOT-23-5, θJA --------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Operating Junction Temperature Range -----------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 2) HBM (Human Body Mode) ---------------------------------------------------------------------------------------------MM (Machine Mode) ------------------------------------------------------------------------------------------------------ −0.3V to 7V 0.4W 250°C /W 260°C −20°C to 100°C −65°C to 150°C 8kV 700V 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 RT9701BCB RT9701BCB RT9701BCB RT9701BCB RT9701BCBL RT9701BCB Symbol VIN RDS(ON) Test Conditions Min 3.5 Typ -85 87 23 400 1.5 1.0 --0.1 0.5 3 100 130 20 Max 6 100 100 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 = 5V RL = 10Ω, 90% Settling RL = 2Ω VOUT = 0V, measured prior to thermal shutdown ----1.1 -2.0 -- TR ILIM IOS IOFF UVLO EN = “0” --2.8 ---- ILEAKAGE EN = “0”, VOUT = 0V TSD ΔTSD Note 1. Stresses listed as the above “ Absolute Maximum Ratings” may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2. Devices are ESD sensitive. Handling precaution recommended. Note 3. θJA i s measured in the natural convection at T A = 25 °C on a low effective thermal conductivity test board of JEDEC 51-3 thermal measurement standard. DS9701B-04 March 2007 www.richtek.com 3 RT9701B (Refer to Test Circuit) Preliminary Typical Operating Characteristics Quiescent Current vs. Temperature 40 35 Quiescent Current vs. Input Voltage 40 35 VIN = 5V TA = 25°C Quiescent Current (uA) Quiescent Current (uA) 30 25 20 15 10 5 0 -20 -5 10 25 40 55 70 85 100 30 25 20 15 10 5 0 3.5 3.8 4.0 4.3 4.5 4.8 5.0 5.3 5.5 5.8 6.0 Temperature (°C) Input Voltage (V) On-Resistance vs. Temperature 200 175 On-Resistance vs. Input Voltage 100 95 VIN = 5V TA = 25°C On-Resistance (mΩ) RT9701BCBL On-Resistance (mΩ) 150 125 100 75 50 25 0 -20 -5 10 25 40 55 90 85 RT9701BCB RT9701BCB RT9701BCBL 80 75 70 70 85 100 3.5 3.8 4.0 4.3 4.5 4.8 5.0 5.3 5.5 5.8 6.0 Temperature (°C) ℃) Input Voltage(V) Current Limit vs. Temperature 2.20 2.00 Current Limit vs. Input Voltage 1.80 1.58 1.35 VIN = 5V TA = 25°C Current Limit (A) 1.80 Current Limit (A) 1.60 1.40 1.20 1.00 0.80 0.60 -20 -5 10 25 40 55 70 85 100 1.13 0.90 0.68 0.45 0.23 0.00 3.5 3.8 4.0 4.3 4.5 4.8 5.0 5.3 5.5 5.8 6.0 Temperature (°C) Input Voltage (V) www.richtek.com 4 DS9701B-04 March 2007 Preliminary RT9701B Short Circuit Current vs. Input Voltage 1950 1.950 Short Circuit Current vs. Temperature 1400 1.4 VIN = 5V TA = 25°C Short Circuit Current (A) 1 1300 1.3 1200 1.2 1100 1.1 1000 1.0 900 0.9 800 0.8 700 0.7 600 0.6 Short Circuit Current (A) 1700 1.7 1450 1.45 1200 1.2 950 0.95 700 0.7 450 0.45 200 0.2 0.5 500 -20 -5 10 25 40 55 70 85 100 3.5 3.8 4.0 4.3 4.5 4.8 5.0 5.3 5.5 5.8 6.0 Temperature (°C) Input Voltage (V) EN Threshold vs. Temperature 2.4 2.0 EN Threshold vs. Input Voltage 2.4 2.0 VIN = 5V TA =25°C EN Threshold (V) EN Threshold (V) 1.6 1.6 1.2 0.8 0.4 0.0 Rising Rising 1.2 0.8 0.4 0.0 -20 -5 10 25 40 55 70 85 100 Falling Falling 3.5 3.8 4.0 4.3 4.5 4.8 5.0 5.3 5.5 5.8 6.0 Temperature (°C) Input Voltage (V) Turn On Rising Time vs. Temperature 400 350 300 250 200 150 100 -20 -5 10 25 40 55 70 85 100 Shutdown Supply Current vs. Temperature 0.9 VIN = 5V Shutdown Supply Current (uA) VIN = 5V 0.8 0.6 0.5 0.3 0.2 0.0 -20 -5 10 25 40 55 70 85 100 Turn On Rising Time (us) Temperature (°C) Temperature (°C) DS9701B-04 March 2007 www.richtek.com 5 RT9701B Preliminary Turn-Off Leakage Current vs. Temperature A 3.5 UVLO Threshold vs. Temperature 4.5 VIN = 5V 3.0 2.5 2.0 1.5 1.0 0.5 0.0 -20 -5 10 25 40 55 70 85 100 VIN = 5V Turn-Off Leakage Current (uA) UVLO Threshold (V) 4 3.5 3 2.5 2 -20 -5 10 25 40 55 70 85 100 Temperature (°C) Temperature (°C) Turn - On Response VIN = 5V VIN = 5V Turn - Off Response CH1: VEN: 5V/Div CH2: IL: 100mA/Div CH3: VOUT: 2V/Div CH1 CH1 CH2 CH2 CH1: VEN: 5V/Div CH2: VOUT: 1V/Div RL = 10Ω, COUT = 1uF CH3 RL = 30Ω, COUT = 1uF Time (100us/Div) Time (50us/Div) UVLO at Rising CH1: VIN: 1V/Div CH2: VOUT: 1V/Div RL = 30Ω, COUT = 1uF UVLO at Falling CH1: VIN: 1V/Div CH2: VOUT: 1V/ Div RL = 30Ω, COUT = 1uF CH1 CH2 CH1 CH2 Time (10ms/Div) Time (500us/Div) www.richtek.com 6 DS9701B-04 March 2007 Preliminary RT9701B Soft - start Short Circuit Response CH1: VIN: 2V/Div Inrush Short Circuit Response CH1: VIN: 2V/Div VDROP=1.2V, depend on CIN ESR IPEAK : depend on ESR & ESL CH1 CH1 CH2: IL: 1A/Div CH2 CH2: IL: 1A/Div CIN = 1uF, COUT = 1000uF CH2 CIN = 1uF Time (25us/Div) Time (50us/Div) Ramped Load Response CH1 VOUT = 4.9V Current Limit Threshold VOUT = 4.6V Thermal Shut Dowm Response CH1 CH3 1.1A Thermal Shut Down CH2 CH2 CH2: IOUT: 500mA/Div VIN = 5V, COUT = 1uF CH1: VEN = 5V/Div, CH3:IOUT@RL1Ω:1A/Div CH2: IOUT@short:1A/DiV, VIN = 5V Time (1ms/Div) Time (50ms/Div) Current Limit Response Current Limit Response COUT = 1uF COUT = 33uF COUT = 100uF COUT = 1uF COUT = 33uF COUT = 100uF IOUT (1A/Div) VIN = 5V, RL = 1Ω IL (1A/Div) VIN = 5V, RL = 1Ω Time (100us/Div) Time (100us/Div) DS9701B-04 March 2007 www.richtek.com 7 RT9701B Current Limit Response Preliminary CH1 Loading trigger CH2 CH2: IOUT: 1A/Div VIN = 5V, COUT = 0.1uF RL = 1Ω Time (5us/Div) www.richtek.com 8 DS9701B-04 March 2007 Preliminary Application Information The RT9701B 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 3V (typical). If input voltage drops below 3V (typical), UVLO shuts off the MOSFET switch. 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. 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. DS9701B-04 March 2007 RT9701B 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 RT9701B is implanted in device end application, minimum 1μF capacitor from VOUT to GND is recommended and higher capacitor values are also preferred. 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 (RT9701BCB) or connect VIN to a fixed voltage under UVLO. 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. www.richtek.com 9 RT9701B Preliminary 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. VIN CIN 1uF RT9701BCBL VIN VOUT VIN GND COUT VOUT VOUT1 VOUT2 COUT 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 RT9701BCB VIN VOUT EN GND VOUT VOUT1 COUT VOUT2 COUT Chip Enable Figure 2. High Side Power Switch with Chip Enable Control www.richtek.com 10 DS9701B-04 March 2007 Preliminary Outline Dimension RT9701B 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 DS9701B-04 March 2007 www.richtek.com 11