RT9728BHGQW

® RT9728B 120mΩ Ω, 1.8A Power Switch with Adjustable Current Limit General Description Features The RT9728B is a cost effective, low voltage, single P-MOSFET power switch IC for USB application with a adjustable current limit feature. Low switch-on resistance (typ. 120mΩ) and low supply current (typ. 120μA) are realized in this IC. The RT9728B offers a adjustable current limit threshold between 75mA and 1.8A (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 due to high inrush current. The RT9728B is an ideal solution for USB power supplies and can support flexible applications since it is suitable for various current limit requirements. It is available in the SOT-23-6 and WDFN-6L 2x2 packages.          ±10% Current Limit Accuracy @ 1.3A Adjustable Current Limit : 75mA to 1.8A (typ.) Meet USB Current Limiting Requirements Operating Voltage Range : 2.5V to 5.5V Reverse Input− −Output Voltage Protection Built-in Soft-Start 120mΩ Ω P-MOSFET 120μ μA Supply Current RoHS Compliant and Halogen Free Ordering Information RT9728B Package Type E : SOT-23-6 QW : WDFN-6L 2x2 Lead Plating System G : Green (Halogen Free and Pb Free) Applications      H : Chip Enable High L : Chip Enable Low USB Bus/Self Powered Hubs USB Peripheral Ports ACPI Power Distribution Battery Power Equipment 3G/3.5G Data Card, Set-Top Boxes Note : Richtek 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. Simplified Application Circuit VIN RFAULT CIN FAULT Signal FAULT ILIM Enable EN/EN GND Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS9728B-04 VIN VOUT RT9728B November 2020 VOUT RILIM is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT9728B Marking Information RT9728BHGE RT9728BLGE 0J= : Product Code 0K= : Product Code 0K=DNN 0J=DNN DNN : Date Code RT9728BLGQW RT9728BHGQW 1Q : Product Code 1R : Product Code W : Date Code 1RW DNN : Date Code 1QW W : Date Code Pin Configuration (TOP VIEW) 6 5 2 4 VOUT 1 3 ILIM FAULT 2 GND VOUT ILIM FAULT 3 7 6 VIN 5 GND EN/EN 4 VIN GND EN/EN SOT-23-6 WDFN-6L 2x2 Functional Pin Description Pin No. Pin Name Pin Function SOT-23-6 WDFN-6L 2x2 1 6 VIN Power input. 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 Enable control input. 4 3 FAULT Active-low open-drain output. Asserted during over-current, over-temperature, or reverse-voltage conditions. 5 2 ILIM Current limit setting. Connect an external resistor is used to set current limit threshold, and 15k  RILIM  232k is recommended. 6 1 VOUT Power switch output. Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 is a registered trademark of Richtek Technology Corporation. DS9728B-04 November 2020 RT9728B Functional Block Diagram Reverse Voltage Comparator + Switch well - Current Sense VIN VOUT 4ms Deglitch EN/EN Drive Current Limit FAULT UVLO Thermal Sense 7.5ms Deglitch GND ILIM Operation The RT9728B is a current-limited power switch using P-MOSFET for applications where short-circuit or heavy capacitive loads will be encountered. These devices allow users to adjust the current limit threshold between 75mA and 1.8A (typ.) via an external resistor. Additional device shutdown features include over-temperature protection and reverse-voltage protection. Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS9728B-04 November 2020 The RT9728B provides built-in soft-start function. The driver controls the gate voltage of the power switch. The driver incorporates circuitry that controls the rising time and falling time of the output voltage to limit large inrush current and voltage surges. The RT9728B enters constant-current mode when the load exceeds the current limit threshold. is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT9728B Absolute Maximum Ratings         (Note 1) Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------Other Pins ------------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C SOT-23-6 -------------------------------------------------------------------------------------------------------------------WDFN-6L 2x2 -------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) SOT-23-6, θJA --------------------------------------------------------------------------------------------------------------WDFN-6L 2x2, θJA --------------------------------------------------------------------------------------------------------WDFN-6L 2x2, θJC -------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Model) ---------------------------------------------------------------------------------------------- Recommended Operating Conditions    −0.3V to 6.5V −0.3V to 6V 0.4W 0.606W 250°C/W 165°C/W 7°C/W 260°C 150°C −65°C to 150°C 2kV (Note 4) Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------- 2.5V to 5.5V Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C Electrical Characteristics (VIN = 3.6V, 15kΩ ≤ RILIM ≤ 232kΩ, TA = 25°C, unless otherwise specified) Parameter EN Input Voltage Symbol Test Conditions Min Typ Max Logic-High VIH 1.1 -- -- Logic-Low VIL -- -- 0.66 (nominal 1%) from ILIM to GND 15 -- 232 VIN rising -- 2.3 -- VIN falling -- 2.1 -- -- 1 3 RILIM = 20k -- 120 170 RILIM = 210k -- 120 170 Unit V Current Limit Threshold Resistor Range RILIM Under-Voltage Lockout Threshold VUVLO Shutdown Current ISHDN VIN = 3.6V, no load on VOUT, VEN = 0V Quiescent Current IQ VIN = 5.5V, no load on VOUT Reverse Leakage Current IREV VOUT = 5V, VIN = 0V -- 1 10 A ISW = 0.2A -- 120 -- m RILIM = 20k 1166 1295 1425 RILIM = 49.9k 468 520 572 RILIM = 210k 104 130 156 -- 75 -- Static Drain-Source On-State RDS(ON) Resistance Current Limit ILIM ILIM shorted to VIN Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 k V A A mA is a registered trademark of Richtek Technology Corporation. DS9728B-04 November 2020 RT9728B 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 4 6 100 -- 0 mA -- 160 -- °C Reverse Voltage Comparator Trip Point (VOUT VIN) FAULT Output Low Voltage VOL FAULT Flag Assertion Offset VFAULT _ OFS Offset between fault flag assertion level versus ILIM trigger level (Note 5) Thermal Shutdown Threshold TSD (Note 5) ms Note 1. Stresses beyond those listed “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. θJA is measured at TA = 25°C on a low effective thermal conductivity single-layer test board per JEDEC 51-3. θJC 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. Note 5. Guarantee by design. Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS9728B-04 November 2020 is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT9728B Typical Application Circuit VIN RFAULT 100k CIN 10µF VOUT VIN COUT 150µF RT9728B FAULT Signal FAULT ILIM Chip Enable EN/EN GND Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 VOUT Ferrite Bead VBUS USB Port RILIM is a registered trademark of Richtek Technology Corporation. DS9728B-04 November 2020 RT9728B Typical Operating Characteristics Supply Current vs. Temperature Fault Deglitch Timing vs. Temperature 150 10 Fault Deglitch Timing (ms) Supply Current (μA) 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 (mΩ ) 140 VIN = 3.6V 110 100 90 VIN = 5V 80 1.4 1.3 1.2 70 RILIM = 20kΩ 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 © 2020 Richtek Technology Corporation. All rights reserved. DS9728B-04 November 2020 125 -50 -25 0 25 50 75 100 125 Temperature (°C) is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT9728B Power On from EN VIN (5V/Div) VEN (5V/Div) VOUT (2V/Div) I IN (2A/Div) VIN (5V/Div) Power Off from EN VIN (5V/Div) VEN (5V/Div) RT9728BH VIN = 5V, COUT = 100μF, RILIM = 13kΩ, ROUT = 5Ω VOUT (2V/Div) I IN (2A/Div) RT9728BH VIN = 5V, COUT = 100μF, RILIM = 13kΩ, ROUT = 5Ω Time (1ms/Div) Time (1ms/Div) Power On from EN Power Off from EN RT9728BL VIN = 5V, COUT = 100μF, RILIM = 13kΩ, ROUT = 5Ω VIN (5V/Div) VEN (5V/Div) VEN (5V/Div) VOUT (5V/Div) I IN (2A/Div) VOUT (5V/Div) I IN (2A/Div) RT9728BL VIN = 5V, COUT = 100μF, RILIM = 13kΩ, ROUT = 5Ω Time (1ms/Div) Time (1ms/Div) Current Limit Current Limit Full Load (5Ω) to Short Circuit Short Circuit to Full Load (5Ω) VOUT (2V/Div) Fault (5V/Div) VOUT (2V/Div) Fault (5V/Div) I IN (1A/Div) I IN (1A/Div) VIN = 5V, COUT = 150μF, RILIM = 20kΩ Time (2.5ms/Div) Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 VIN = 5V, COUT = 150μF, RILIM = 20kΩ Time (2.5ms/Div) is a registered trademark of Richtek Technology Corporation. DS9728B-04 November 2020 RT9728B Current Limit Current Limit No Load to Short Circuit Short Circuit to No Load VIN = 5V, COUT = 150μF, RILIM = 20kΩ VIN = 5V, COUT = 150μF, RILIM = 20kΩ 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 = 20kΩ 1400 1200 1000 800 600 400 200 0 0 200 400 600 800 VIN - VOUT (mV) Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS9728B-04 November 2020 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 = 200kΩ 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. www.richtek.com 9 RT9728B Applications Information The RT9728B is a single P-MOSFET power switch with an active-high/low enable input, optimized for self-powered and bus-powered Universal Serial Bus (USB) applications. The switch's low R DS(ON) meets USB voltage drop requirements and a flag output is available to indicate fault conditions to the local USB controller. its target). For short ILIM to VIN condition (75mA) the fault flag may go low. Once the current limit threshold is exceeded, the device enters constant-current mode until either thermal shutdown occurs or the fault is removed. Figure 1 shows the curve of current limit value vs. RILIM resistor. The recommended RILIM resistor selection is shown in Table 1. Current Limit and Short-Circuit Protection Current Limit Threshold vs. RILIM 2000 Current Limit Threshold (mA) When a heavy load or short-circuit situation occurs while the switch is enabled, a large transient current may flow through the device. The RT9728B includes current-limit circuitry to prevent the MOSFET switch and the hub downstream ports from damage due to large transient current. The RT9728B provides an adjustable current limit threshold between 120mA and 1.8A (typ) via an external resistor, RILIM, whose resistance is between 15kΩ and 232kΩ. However, if the ILIM pin is connected to VIN, the current limit threshold will be 75mA (typ). The maximum −100mA fault flag assertion offset needs cautions, especially for very low ILIM applications. Taking the application of ILIM = 250mA as an example, the minimum fault flag assertion level might be 150mA (40% error versus 1750 1500 1250 1000 750 500 250 0 0 30 60 90 120 150 180 210 240 RILIM (kΩ) Figure 1. Current Limit Threshold vs. RILIM Table 1. Recommended RILIM Resistor Selection Desired Nominal Current Limit (mA) 75 120 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 Ideal Resistor (k) Closet 1% Resistor (k) Short ILIM to VIN 226.1 226.0 134.0 133.0 88.5 88.7 65.9 66.5 52.5 52.3 43.5 43.2 37.2 37.4 32.4 32.4 28.7 28.7 25.8 26.1 23.4 23.2 21.4 21.5 19.7 19.6 18.5 18.7 17.3 17.4 16.2 16.2 15.2 15.0 14.4 14.3 Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 Actual Limits (Include R Tolerance) IOS Min (mA) 50.0 101.3 173.7 262.1 351.1 443.9 535.1 616.0 708.7 797.8 875.4 982.1 1057.9 1158.0 1225.7 1317.3 1414.8 1528.1 1602.9 IOS Nom (mA) 75.0 120.0 201.5 299.4 396.7 501.6 604.6 696.0 800.8 901.5 989.1 1109.7 1195.4 1308.5 1385.0 1488.5 1598.7 1726.7 1811.2 IOS Max (mA) 100.0 142.1 233.9 342.3 448.7 562.4 674.1 776.0 892.9 1005.2 1102.8 1237.3 1332.9 1459.0 1544.3 1659.7 1782.6 1925.3 2019.5 is a registered trademark of Richtek Technology Corporation. DS9728B-04 November 2020 RT9728B Fault Flag The RT9728B provides a FAULT signal pin which is an open-drain N-MOSFET output. This open-drain output is pulled low when current exceeds current limit threshold. The FAULT output is capable of sinking a 1mA load to 180mV (typ.) above ground. The FAULT pin requires a pull-up resistor; this resistor should be large in value to reduce energy drain. A 100kΩ 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. Supply Filter/Bypass Capacitor A 10μF 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. Output Filter Capacitor 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 bypass capacitors at the power connector pins are recommended for EMI and ESD protection. The bypass capacitor itself should have a low dissipation factor to allow decoupling at higher frequencies. For commercial applications where the ambient temperature is 0°C to 70°C (such as a PC or USB hub), RT9728B supports an output capacitor range of up to Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS9728B-04 November 2020 120μF. For industrial applications with an ambient temperature of −40°C to 125°C, please limit the output capacitance to less than 50μF to ensure normal startup. Chip Enable Input The RT9728BH/L is 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 1μA typically. Floating the input may cause unpredictable operation and EN/EN should not be allowed to go negative with respect to GND. The EN/EN signal must be asserted after input voltage ready or higher than UVLO threshold to satisfy the power sequence. Under-Voltage Lockout Under-Voltage Lockout (UVLO) prevents the MOSFET switch from turning on until input voltage exceeds approximately 2.3V (typ.). If input voltage drops below approximately 2.1V (typ.), UVLO turns off the MOSFET switch. Thermal Considerations 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 : PD(MAX) = (TJ(MAX) − TA) / θJA where TJ(MAX) is the maximum junction temperature, TA is the ambient temperature, and θJA is the junction to ambient thermal resistance. For recommended operating condition specifications, the maximum junction temperature is 125°C. The junction to ambient thermal resistance, θJA, is layout dependent. For SOT-23-6 packages, the thermal resistance, θJA, is 250°C/ W on a standard JEDEC 51-3 single-layer thermal test board. For WDFN-6L 2x2 packages, the thermal resistance, θJA, is 165°C/W on a standard JEDEC 51-3 single-layer thermal test board. The maximum power dissipation at TA = 25°C can be calculated by the following formula : is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT9728B PD(MAX) = (125°C − 25°C) / (250°C/W) = 0.400W for SOT-23-6 package PD(MAX) = (125°C − 25°C) / (165°C/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, θJA. 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 0.25 0.20 0.15 0.10 0.05 0.00 WDFN-6L 2x2 SOT-23-6 0 25 50 75 100 125 Ambient Temperature (°C) Figure 2. Derating Curve of Maximum Power Dissipation Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 is a registered trademark of Richtek Technology Corporation. DS9728B-04 November 2020 RT9728B 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 © 2020 Richtek Technology Corporation. All rights reserved. DS9728B-04 November 2020 is a registered trademark of Richtek Technology Corporation. www.richtek.com 13 RT9728B 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. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. 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. www.richtek.com 14 DS9728B-04 November 2020