® RT9746 VBUS OVP with a PTVS Diode General Description Features The RT9746 is an overvoltage protection devices feature a low 35mΩ (typ) RON internal FET with PTVS diode. The PTVS also protects the devices from surges up to 100V. PTVS Diode Embedded for VBUS Surge Protection When the input voltage exceeds the overvoltage threshold, the internal FET is turned off to prevent damage to the protected down stream components. Warning Indicator for OVP or UVP 28V Maximum Rating for DC Adapter Integrated Over-Voltage and Over Current Protection FET on VBUS for Fault Isolation Applications The internal Over Voltage Thresholds (OVP) are preset to 6.8V typical. The RT9746 also feature an over-current protection and up to 4.5A. The RT9746 is offered in a small WL-CSP-12B (BSC) package provides small PCB area applications. Cellular Phone Smart Handheld Device Pin Configurations (TOP VIEW) Ordering Information RT9746 Package Type WSC : WL-CSP-12B 1.92x1.27 OVP Threshold Option Default : 6.8V A : 11.5V B : 14.5V C : 6.2V A1 A2 A3 A4 GND VOUT VOUT GND_ PTVS B1 B2 B3 B4 WRNB VOUT VIN GND_ PTVS C1 C2 C3 C4 OVPFB VIN VIN GND_ PTVS WL-CSP-12B 1.92x1.27 (BSC) Marking Information Note : RT9746WSC Richtek products are : RoHS compliant and compatible with the current require- Suitable for use in SnPb or Pb-free soldering processes. 3CW 3C : Product Code W : Date Code ments of IPC/JEDEC J-STD-020. Simplified Application Circuit RT9746 VIN Adaptor CIN VOUT COUT R2 VDDIO OVPFB R1 Copyright © 2016 Richtek Technology Corporation. All rights reserved. R3 WRNB GND_PTVS DS9746-00 March 2016 Charger Processor GND is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT9746 Functional Pin Description Pin No Pin Name Pin Function A1 GND Common Ground Of Internal Circuits. A2, A3, B2 VOUT Output from VBUS Load-Switch. B1 WRNB Inverse Warning Signal (OCP,OTP, OVP, UVLO) Flag Output (Open-Drain). A4, B4, C4 GND_PTVS Common Ground of Power TVS Diode. B3, C2, C3 VIN VBUS from Power Adaptor. OVPFB External OVP Adjustment Setting. (if no used, be surely tied to GND) C1 Function Block Diagram VIN VOUT PreRegulator OCP GND Power FET OTP UVLO OVPFB OVP SEL External & Internal OVP Digital Control GND_PTVS POR I/O Buffer WRNB Operation The RT9746 is a VBUS OVP protector switch. The OVP function is optimized to protect low voltage system from abnormal high input voltage (up to 28V) in handheld application. RT9746 is also embedded Power-TVS diode (PTVS) on VBUS pin for surge protection. If surge waveform is above 30V, it will be clamped to 30V due to PTVS diode. When plugging in VBUS, the OCP will be soft-start in 8ms in order to reduce in rush current and internal VOUT deglitch time is 16/32/64/128ms which is set by fuse. The OCP after soft-start is up to 4.5A for high current application. Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 is a registered trademark of Richtek Technology Corporation. DS9746-00 March 2016 RT9746 Absolute Maximum Ratings (Note 1) VIN, OVPFB ---------------------------------------------------------------------------------------------------------------VOUT ------------------------------------------------------------------------------------------------------------------------System Level with Air Discharger, VIN, GND ----------------------------------------------------------------------System Level with Contact Discharger, VIN, GND ----------------------------------------------------------------All Other Inputs -----------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C WL-CSP-12B 1.92x1.27 (BSC) ---------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) WL-CSP-12B 1.92x1.27 (BSC), θJA ---------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Model) ---------------------------------------------------------------------------------------------MM (Machine Model) ----------------------------------------------------------------------------------------------------CDM (Charged Device Model) -----------------------------------------------------------------------------------------Surge (VIN) ----------------------------------------------------------------------------------------------------------------- Recommended Operating Conditions −0.3V to 28V −0.3V to 15V ±15kV ±8kV −0.3V to 6V 1.67W 59.6°C/W 150°C 260°C −65°C to 150°C 2kV 200V 2kV 100V (Note 4) USB Supply Input Voltage, VIN ---------------------------------------------------------------------------------------I/O Supply Voltage (VDDIO) ---------------------------------------------------------------------------------------------VOUT Capacitors ---------------------------------------------------------------------------------------------------------Junction Temperature Range -------------------------------------------------------------------------------------------Ambient Temperature Range -------------------------------------------------------------------------------------------- 3V to 6.7V 1.8V to 3.6V 1μF to 10μF −40°C to 125°C −40°C to 85°C Electrical Characteristics (VIN = 5V, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min TYP Max Unit DC Characteristics Input Clamp Voltage VIN_CLAMP IIN = 10mA, TA = 25°C -- 31 -- V VIN Supply Current IVBUS_S VBUS = 5V, IOUT = 0mA -- 130 180 A VIN POR Threshold Only for VOUT VPOR Rising 2.5 2.7 2.9 V VBUS POR Hysteresis Only for VOUT VPOR_Hys Falling -- 100 -- mV Deglitch Time of POR Only for VOUT tPOR by EFUSE setting (16/32/64/128ms) -- 32 -- ms 6.6 6.8 7 RT9746A 11.15 11.5 11.85 RT9746B 14 14.5 15 RT9746C 6 6.2 6.4 RT9746 OVP Threshold Voltage VOVP Rising Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS9746-00 March 2016 V is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT9746 Parameter Min TYP Max Unit Falling -- 150 -- mV OVP Propagation Delay to tOVP_PD Turn Off VBUSOUT VBUS = 5V to 10V, (6V/s) -- 0.18 0.25 s OVP Recover Delay tOVP_RD VBUS = 10V to 5V -- 8 -- ms OCP Threshold Current IOCP -- 4.5 5 A OCP Blanking Time tOCP_B -- 180 -- s OCP Recover delay tOCP_RD -- 64 -- ms OTP Threshold to turn off only for VBUS_OUT TOTP_FET OVP Hysteresis Symbol VOVP_HYS OTP Threshold Hysteresis TOTP_FET_HYS only for VBUS_OUT Test Conditions Rising (Note5) -- 160 -- °C Falling (Note5) -- 20 -- °C OTP Recover Delay tOTD_RD -- 8 -- ms OCP Soft-Start Time tss -- 8 -- ms FET On Resistance RON_FET -- 35 42 m External OVP Set Threshold VREF_EXT -- 1.2 -- V External OVP Adjustment Range VOVP_EXT 4 -- 20 V External OVP Select Threshold (Rising) VOVP_SEL -- 0.3 -- V -- 100 -- mV -- -- 15 IBUS_OUT = 1000mA, VBUS = 5V TA = 25°C External OVP Select Threshold Hysteresis WRNB Open-Drain Impedance VBUS = 5V 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 high effective thermal conductivity four-layer test board per JEDEC 51-7. 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. Guaranteed by design. Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 is a registered trademark of Richtek Technology Corporation. DS9746-00 March 2016 RT9746 Typical Application Circuit RT9746 B3, C2, C3 Adaptor CIN 0.1µF VIN A2, A3, B2 Charger COUT 1µF R2 C1 VDDIO OVPFB R1 R3 WRNB GND_PTVS A4, B4, C4 Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS9746-00 March 2016 VOUT B1 Processor GND A1 is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT9746 Typical Operating Characteristics Input Supply Current vs. Temperature Input Supply Current vs. Supply Voltage 150 150 Input Supply Current (μA)1 Input Supply Current (μA) 160 140 130 120 85°C 25°C −40°C 110 100 90 145 140 135 130 125 VIN = 5V 120 80 2.5 3 3.5 4 4.5 5 5.5 6 6.5 -50 7 -25 Supply Voltage (V) 0 25 50 75 100 125 150 Temperature (°C) Normalized RDS(ON) vs. Output Current Normalized VOVP vs. Temperature 1.06 2.0 1.8 1.6 Normalized RDS(ON) Normalized VOVP 1.04 1.02 1.00 0.98 1.4 1.2 1.0 0.8 0.6 0.4 0.96 0.2 0.94 VIN = 5V 0.0 -50 -25 0 25 50 75 100 125 150 0 0.5 1 1.5 2 Temperature (°C) Output Current (A) Normalized RDS(ON) vs. Temperature Power Up 2.0 2.5 3 VIN = 5V, IOUT = 0A, CL = 100μF 1.8 Normalized RDS(ON) 1.6 1.4 1.2 VIN (2V/Div) 1.0 0.8 0.6 0.4 0.2 VIN = 5V, IOUT = 1A VOUT (2V/Div) 0.0 -50 -25 0 25 50 75 100 125 150 Time (5ms/Div) Temperature (°C) Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 is a registered trademark of Richtek Technology Corporation. DS9746-00 March 2016 RT9746 80V Surge without RT9746 Power Up VIN = 5V, IOUT = 0A, CL = 1000μF VIN (2V/Div) VIN (20V/Div) VOUT (2V/Div) Time (5ms/Div) Time (10μs/Div) 80V Surge with RT9746 VIN (20V/Div) Time (10μs/Div) Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS9746-00 March 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT9746 Application Information Power Up The RT9746 has a threshold of 2.7V power on reset (POR) with a built-in hysteresis of 100mV. Before the input voltage reaches the POR threshold, the RT9746 is off. When the input voltage is over the POR threshold, the VOUT of RT9746 will delay for 32ms which includes soft-start time of 8ms. The 32ms delay allows the transient at the input during a hot insertion of the power supply to settle down before the IC starts to operate. During the soft-start transition, the RT9746 slowly turns on the internal MOSFET to reduce the inrush current. Over Temperature Protection (OTP) The RT9746 monitors its internal temperature to prevent thermal failures. The chip turns off the MOSFET when the junction temperature reaches 160°C. The IC will resume after the junction temperature is cooled down 20°C. Input Over-Voltage Protection The RT9746 provides input over-voltage protection via internal or external resistor to set OVP level. If OVPFB is connected to GND, the RT9746 uses the internal OVP level setting. If an external resistor-divider is connected to OVPFB and VOVPFB exceeds the VOVP_SEL voltage, the RT9746 will adopt external OVP level setting. The OVP level VOVP is set as below. R2 VOVP = VREF_EXT x 1+ R1 When the input volatge exceeds the OVP level, the RT9746 will turn off internal MOSFET around 0.18us to prevent the high input volatge from damaging the end system. When the input volatge returns to normal operation volatge range with hysteresis (internal 150mV, external 100mV), the RT9746 will turn on the MOSFET to re-enable output. situation keeps for 180μs, the internal MOSFET will be turned off. 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 WL-CSP-12B 1.92x1.27 (BSC) package, the thermal resistance, θJA, is 59.6°C/W on a standard JEDEC 51-7 four-layer thermal test board. The maximum power dissipation at TA = 25°C can be calculated by the following formula : PD(MAX) = (125°C − 25°C) / (59.6°C/W) = 1.67W for WL-CSP-12B 1.92x1.27 (BSC) package The maximum power dissipation depends on the operating ambient temperature for fixed T J(MAX) and thermal resistance, θJA. The derating curve in Figure 1 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation. Over-Current Protection (OCP) The RT9746 monitors the output current to prevent the output short or the charging of the battery with an excessive current. The RT9746 has a built-in 180μs delay time to prevent any transient noise triggering the OCP. If the OCP Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 is a registered trademark of Richtek Technology Corporation. DS9746-00 March 2016 RT9746 Maximum Power Dissipation (W)1 2.0 Four-Layer PCB 1.6 1.2 0.8 0.4 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 1. Derating Curve of Maximum Power Dissipation Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS9746-00 March 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT9746 Outline Dimension Symbol Dimensions In Millimeters Dimensions In Inches Min. Max. Min. Max. A 0.500 0.600 0.020 0.024 A1 0.170 0.230 0.007 0.009 b 0.240 0.300 0.009 0.012 D 1.220 1.320 0.048 0.052 D1 E 0.800 1.870 0.031 1.970 0.074 0.078 E1 1.200 0.047 e 0.400 0.016 WL-CSP-12B 1.92x1.27 (BSC) 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 10 DS9746-00 March 2016