(R) RT9728A 120m , 1.3A Power Switch with Programmable Current Limit General Description Features The RT9728A is a cost effective, low voltage, single P-MOSFET high-side power switch IC for USB application with a programmable current limit feature. Low switch-on resistance (typ.120m) and low supply current (typ. 120A) are realized in this IC. The RT9728A can offer a programmable current limit threshold between 75mA and 1.3A (typ.) via an external resistor. The 10% current limit accuracy can be realized for all current limit settings. In addition, a flag output is available to indicate fault conditions to the local USB controller. Furthermore, the chip also integrates an embedded delay function to prevent mis-operation from happening due to high inrush current. The RT9728A is an ideal solution for USB power supply and can support flexible applications since it is functional for various current limit requirements. It is available in SOT-23-6 and WDFN-6L 2x2 packages. Ordering Information 10% Current Limit Accuracy @ 1.3A Adjustable Current Limit : 75mA to 1.3A (typ.) Meets USB Current Limiting Requirements Operating Voltage Range : 2.5V to 5.5V Reverse Input- -Output Voltage Protection Built-in Soft-Start 120m High-Side MOSFET 120 A Supply Current RoHS Compliant and Halogen Free Applications USB Bus/Self Powered Hubs USB Peripheral Ports ACPI Power Distribution Battery Power Equipment 3G/3.5G Data Card, Set-Top Boxes Pin Configuration (TOP VIEW) RT9728A Package Type E : SOT-23-6 QW : WDFN-6L 2x2 Lead Plating System G : Green (Halogen Free and Pb Free) Z : ECO (Ecological Element with Halogen Free and Pb free) VOUT ILIM FAULT 6 RoHS compliant and compatible with the current require- Suitable for use in SnPb or Pb-free soldering processes. ments of IPC/JEDEC J-STD-020. Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. DS9728A-08 November 2018 2 3 SOT-23-6 VOUT 1 ILIM FAULT 2 GND Richtek products are : 4 VIN GND EN/EN H : Chip Enable High L : Chip Enable Low Note : 5 3 7 6 VIN 5 GND EN/EN 4 WDFN-6L 2x2 is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT9728A Marking Information RT9728AHGE RT9728ALGE 02= : Product Code 01= : Product Code 01=DNN 02=DNN DNN : Date Code RT9728AHGQW DNN : Date Code RT9728ALGQW 17 : Product Code 19 : Product Code W : Date Code 17W W : Date Code 19W RT9728AHZQW RT9728ALZQW 17 : Product Code 19 : Product Code W : Date Code 17W W : Date Code 19W Typical Application Circuit VIN RFAULT 100k CIN 10F VIN VOUT RT9728A FAULT Signal FAULT ILIM Chip Enable EN/EN GND VOUT 150F RILIM Functional Pin Description Pin No. Pin Name Pin Function SOT-23-6 WDFN-6L 2x2 1 6 VIN Input voltage. 2 5, 7 (Exposed Pad) GND Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. 3 4 EN/EN Chip enable. 4 3 FAULT 5 2 ILIM 6 1 VOUT Active-low open-drain output. Asserted during over current, over temperature, or reverse-voltage conditions. Current limit set pin. External resistor used to set current limit threshold. Recommend 19.1k RILIM 232k. Power switch output. Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 is a registered trademark of Richtek Technology Corporation. DS9728A-08 November 2018 RT9728A Functional Block Diagram Reverse Voltage Comparator + Switch well - Current Sense VIN VOUT 4ms Deglitch EN/EN Drive 14 Current Limit FAULT UVLO Thermal Sense 7.5ms Deglitch GND ILIM Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. DS9728A-08 November 2018 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT9728A Absolute Maximum Ratings (Note 1) Supply Input Voltage -----------------------------------------------------------------------------------------------------Other Pin Voltage --------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25C SOT-23-6 -------------------------------------------------------------------------------------------------------------------WDFN-6L 2x2 -------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) SOT-23-6, JA --------------------------------------------------------------------------------------------------------------WDFN-6L 2x2, JA --------------------------------------------------------------------------------------------------------WDFN-6L 2x2, JC -------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Model) ---------------------------------------------------------------------------------------------- Recommended Operating Conditions -0.3V to 6V -0.3V to 6V 0.4W 0.606W 250C/W 165C/W 7C/W 260C 150C -65C to 150C 2kV (Note 4) Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------- 2.5V to 5.5V Junction Temperature Range -------------------------------------------------------------------------------------------- -40C to 125C Ambient Temperature Range -------------------------------------------------------------------------------------------- -40C to 85C Electrical Characteristics (VIN = 3.6V, 19.1k RILIM 232k, TA = 25C, unless otherwise specified) Parameter EN Input Voltage Symbol Test Conditions Min Typ Max Logic-High VIH 1.1 -- -- Logic- Low VIL -- -- 0.66 19.1 -- 232 VIN rising -- 2.3 -- VIN falling -- 2.1 -- -- 1 3 RILIM = 20k -- 120 170 RILIM = 210k -- 120 170 -- 1 3 A -- 160 -- C -- 120 -- m RILIM = 20k 1190 1295 1400 RILIM = 49.9k 468 520 572 RILIM = 210k 110 130 150 ILIM shorted to VIN 50 75 100 Current Limit Threshold Resistor Range RILIM Under Voltage Lockout Threshold VUVLO Shutdown Current ISHDN VIN = 5.5V, no load on VOUT, VEN = 0V Quiescent Current IQ VIN = 5.5V, no load on VOUT Reverse Leakage Current Thermal Shutdown Temperature Static Drain-Source On-State Resistance IREV VOUT = 5.5V, VIN = 0V Current Limit (nominal 1%) from ILIM to GND TSD RDS(ON) ILIM ISW = 0.2A Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 Unit V k V A A mA is a registered trademark of Richtek Technology Corporation. DS9728A-08 November 2018 RT9728A Parameter Symbol Test Conditions Min Typ Max Unit -- 135 -- mV IFAULT = 1mA -- 180 -- mV FAULT Off State Leakage VFAULT = 5.5V -- 1 -- A FAULT Deglitch FAULT assertion or de-assertion due to over current condition 5 7.5 10 FAULT assertion or de-assertion due to reverse voltage condition 2 Reverse Voltage Comparator Trip Point (VOUT VIN) FAULT Output Low Voltage VOL ms 4 6 Note 1. Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and 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 may affect device reliability. Note 2. JA is measured at TA = 25C on a low effective thermal conductivity single-layer test board per JEDEC 51-3. JC is measured at the exposed pad of the package. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. DS9728A-08 November 2018 is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT9728A Typical Operating Characteristics Supply Current vs. Temperature Fault Deglitch Timing vs. Temperature 150 10 Fault Deglitch Timing (ms) Supply Current (A) 140 130 120 110 100 90 80 9 8 7 6 5 -50 -25 0 25 50 75 100 125 -50 -25 0 Temperature (C) 25 50 75 100 125 Temperature (C) Current Limit vs. Temperature On- Resistance vs. Temperature 1.6 150 1.5 130 120 Current Limit (A) On-Resistance (m ) 140 VIN = 3.6V 110 100 90 VIN = 5V 80 1.4 1.3 1.2 70 RILIM = 20k 1.1 60 -50 -25 0 25 50 75 100 -50 125 -25 0 1.4 2.8 Under Voltage Lockout (V) EN/EN Threshold Voltage (V)1 3.0 1.3 1.2 Rising 1.0 0.9 Falling 0.8 50 75 100 125 Under Voltage Lockout vs. Temperature EN/EN Threshold Voltage vs. Temperature 1.5 1.1 25 Temperature (C) Temperature (C) 0.7 2.6 2.4 Rising 2.2 2.0 Falling 1.8 1.6 1.4 1.2 0.6 1.0 0.5 -50 -25 0 25 50 75 100 Temperature (C) Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 125 -50 -25 0 25 50 75 100 125 Temperature (C) is a registered trademark of Richtek Technology Corporation. DS9728A-08 November 2018 RT9728A Power On from EN Power Off from EN VEN (10V/Div) VEN (10V/Div) VOUT (5V/Div) VOUT (5V/Div) I IN (1A/Div) I IN (1A/Div) RT9728AH, VIN = 5V, COUT = 150F, RILIM = 20k, ROUT = 5 RT9728AH, VIN = 5V, COUT = 150F, RILIM = 20k, ROUT = 5 Time (500s/Div) Time (500s/Div) Power On from EN Power Off from EN VEN (10V/Div) VEN (10V/Div) VOUT (5V/Div) VOUT (5V/Div) I IN (1A/Div) I IN (1A/Div) RT9728AL, VIN = 5V, COUT = 150F, RILIM = 20k, ROUT = 5 RT9728AL, VIN = 5V, COUT = 150F, RILIM = 20k, ROUT = 5 Time (500s/Div) Time (500s/Div) Current Limit Current Limit Full Load (5) to Short Circuit Short Circuit to Full Load (5) VOUT (2V/Div) Fault (5V/Div) VOUT (2V/Div) Fault (5V/Div) I IN (1A/Div) I IN (1A/Div) VIN = 5V, COUT = 150F, RILIM = 20k Time (2.5ms/Div) Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. DS9728A-08 November 2018 VIN = 5V, COUT = 150F, RILIM = 20k Time (2.5ms/Div) is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT9728A Current Limit Current Limit No Load to Short Circuit Short Circuit to No Load VIN = 5V, COUT = 150F, RILIM = 20k VIN = 5V, COUT = 150F, RILIM = 20k VOUT (2V/Div) VOUT (2V/Div) Fault (5V/Div) Fault (5V/Div) I IN (1A/Div) I IN (1A/Div) Time (2.5ms/Div) Time (2.5ms/Div) Static Drain-Source Current vs. VIN - VOUT VIN = 5.5V, RILIM = 20k 1400 1200 1000 800 600 400 200 0 0 200 400 600 800 VIN - VOUT (mV) Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 1000 160 Static Drain-Source Current (mA)1 Static Drain-Source Current (mA)1 Static Drain-Source Current vs. VIN - VOUT 1600 VIN = 5.5V, RILIM = 200k 140 120 100 80 60 40 20 0 0 200 400 600 800 1000 VIN - VOUT (mV) is a registered trademark of Richtek Technology Corporation. DS9728A-08 November 2018 RT9728A Applications Information Current Limiting and Short Circuit Protection When a heavy load or short circuit situation occurs while the switch is enabled, large transient current may flow through the device. The RT9728A includes a current-limit circuitry to prevent these large currents from damaging the MOSFET switch and the hub downstream ports. The RT9728A provides an adjustable current limit threshold between 120mA and 1.3A (typ) via an external resistor, RILIM, between 19.1k and 232k. However, if the ILIM pin is connected to VIN, the current limit threshold will be 75mA (typ). Once the current limit threshold is exceeded, the device enters constant-current mode until either thermal shutdown occurs or the fault is removed. The table1 shows a recommended current limit value vs. RILIM resistor. Current Limit Threshold vs. RILIM 1600 Current Limit Threshold (mA) The RT9728A is a single P-MOSFET high-side power switch with active-high/low enable input, optimized for selfpowered and bus-powered Universal Serial Bus (USB) applications. The switch's low RDS(ON) meets USB voltage drop requirements and a flag output is available to indicate fault conditions to the local USB controller. 1400 1200 1000 800 600 400 200 0 20 50 80 110 140 170 200 230 RILIM (k ) Figure 1. Current Limit Threshold vs RILIM Table 1. Recommended RILIM Resistor Selections Desired Nominal Current Limit (mA) Ideal Resistor (k) 75 Closet 1% Resistor (k) Short ILIM to VIN Actual Limits (Include R Tolerance) IOS Min (mA) IOS Nom (mA) IOS Max (mA) 50.0 75.0 100.0 120 226.1 226.0 101.3 120.0 142.1 200 134.0 133.0 173.7 201.5 233.9 300 88.5 88.7 262.1 299.4 342.3 400 65.9 66.5 351.1 396.7 448.7 500 52.5 52.3 443.9 501.6 562.4 600 43.5 43.2 535.1 604.6 674.1 700 37.2 37.4 616.0 696.0 776.0 800 32.4 32.4 708.7 800.8 892.9 900 28.7 28.7 797.8 901.5 1005.2 1000 25.8 26.1 875.4 989.1 1102.8 1100 23.4 23.2 982.1 1109.7 1237.3 1200 21.4 21.5 1057.9 1195.4 1332.9 1300 19.7 19.6 1178.0 1308.5 1439.0 Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. DS9728A-08 November 2018 is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT9728A Fault Flag The RT9728A provides a FAULT signal pin which is an Nchannel open drain MOSFET output. This open drain output goes low when current exceeds current limit threshold, VOUT - VIN exceeds reverse voltage trip level, or the die temperature exceeds 160C approximately. The FAULT output is capable of sinking a 1mA load to typically 180mV above ground. The FAULT pin requires a pull-up resistor; this resistor should be large in value to reduce energy drain. A 100k pull-up resistor works well for most applications. In case of an over current condition, FAULT will be asserted only after the flag response delay time, tD, has elapsed. This ensures that FAULT is asserted upon valid over current conditions and that erroneous error reporting is eliminated. For example, false over current conditions may occur during hot-plug events when extremely large capacitive loads are connected, which induces a high transient inrush current that exceeds the current limit threshold. The FAULT response delay time, tD, is typically 7.5ms. are recommended for EMI and ESD protection. The bypass capacitor itself should have a low dissipation factor to allow decoupling at higher frequencies. Chip Enable Input The RT9728AH/L will be disabled when the EN/EN pin is in a logic-low/high condition. During this condition, the internal circuitry and MOSFET are turned off, reducing the supply current to 1A typical. The maximum guaranteed voltage for a logic-low at the EN/EN pin is 0.66V. A minimum guaranteed voltage of 1.1V at the EN/ EN pin will turn off the RT9728A. Floating the input may cause unpredictable operation. EN/EN should not be allowed to go negative with respect to GND. Under Voltage Lockout Under voltage lockout (UVLO) prevents the MOSFET switch from turning on until input voltage exceeds approximately 2.3V. If input voltage drops below approximately 2.1V, UVLO turns off the MOSFET switch. Supply Filter/Bypass Capacitor Thermal Considerations A 10F low ESR ceramic capacitor connected from VIN to GND and located close to the device is strongly recommended to prevent input voltage drooping during hotplug events. However, higher capacitor values may be used to further reduce the voltage droop on the input. Without this bypass capacitor, an output short may cause sufficient ringing on the input (from source lead inductance) to destroy the internal control circuitry. Note that the input transient voltage must never exceed 6V as stated in the Absolute Maximum Ratings. For continuous operation, do not exceed absolute maximum junction temperature. The maximum power dissipation depends on the thermal resistance of the IC package, PCB layout, rate of surrounding airflow, and difference between junction and ambient temperature. The maximum power dissipation can be calculated by the following formula : Output Filter Capacitor A low ESR 150F aluminum electrolytic capacitor connected between V OUT and GND is strongly recommended to meet the USB standard maximum droop requirement for the hub, VBUS. Standard bypass methods should be used to minimize inductance and resistance between the bypass capacitor and the downstream connector to reduce EMI and decouple voltage droop caused by hot-insertion transients in downstream cables. Ferrite beads in series with VBUS, the ground line and the 0.1F bypass capacitors at the power connector pins Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 PD(MAX) = (TJ(MAX) - TA) / JA where TJ(MAX) is the maximum junction temperature, TA is the ambient temperature, and JA is the junction to ambient thermal resistance. For recommended operating condition specifications, the maximum junction temperature is 125C. The junction to ambient thermal resistance, JA, is layout dependent. For SOT-23-6 packages, the thermal resistance, JA, is 250C/ W on a standard JEDEC 51-3 single-layer thermal test board. For WDFN-6L 2x2 packages, the thermal resistance, JA, is 165C/W on a standard JEDEC 51-3 single-layer thermal test board. The maximum power dissipation at TA = 25C can be calculated by the following formula : is a registered trademark of Richtek Technology Corporation. DS9728A-08 November 2018 RT9728A PD(MAX) = (125C - 25C) / (250C/W) = 0.400W for SOT-23-6 package PD(MAX) = (125C - 25C) / (165C/W) = 0.606W for WDFN-6L 2x2 package Maximum Power Dissipation (W)1 The maximum power dissipation depends on the operating ambient temperature for fixed T J(MAX) and thermal resistance, JA. The derating curves in Figure 2 allow the designer to see the effect of rising ambient temperature on the maximum power dissipation. 0.65 Single-Layer PCB 0.60 0.55 0.50 0.45 0.40 0.35 0.30 WDFN-6L 2x2 SOT-23-6 0.25 0.20 0.15 0.10 0.05 0.00 0 25 50 75 100 125 Ambient Temperature (C) Figure 2. Derating Curve of Maximum Power Dissipation Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. DS9728A-08 November 2018 is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT9728A Outline Dimension H D L C B b A A1 e Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.889 1.295 0.031 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.250 0.560 0.010 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-23-6 Surface Mount Package Copyright (c) 2018 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 is a registered trademark of Richtek Technology Corporation. DS9728A-08 November 2018 RT9728A D2 D L E E2 1 e b A A1 SEE DETAIL A 2 1 2 1 A3 DETAIL A Pin #1 ID and Tie Bar Mark Options Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated. Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.700 0.800 0.028 0.031 A1 0.000 0.050 0.000 0.002 A3 0.175 0.250 0.007 0.010 b 0.200 0.350 0.008 0.014 D 1.950 2.050 0.077 0.081 D2 1.000 1.450 0.039 0.057 E 1.950 2.050 0.077 0.081 E2 0.500 0.850 0.020 0.033 e L 0.650 0.300 0.026 0.400 0.012 0.016 W-Type 6L DFN 2x2 Package Richtek Technology Corporation 14F, No. 8, Tai Yuen 1st Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Richtek products are sold by description only. Customers should obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries. DS9728A-08 November 2018 www.richtek.com 13