HS2950P

HS2950P SEMTECH | Alldatasheet

Document overview

• Manufacturer or author: Provided By alldatasheet.com(free datasheet download site)
• PDF pages: 21

Technical content

Features

• Integrated Load Switch
• Input Voltage Range – 2.7V to 29V
• Up to 5A Output Current
• Low Ron – 25mΩ
• Adjustable Current Limit
• Adjustable Over Voltage Protection
• Automatic Output Discharge
• Adjustable Soft Start
• Automatic Restart from All Faults Except OVP & UVLO
• Fault Flag Output Mechanical Characteristics
• DFN 3.0 x 3.0 x 0.55mm 12 Lead package
• Pb-Free, Halogen Free, RoHS/WEEE compliant
• Pb Free Lead Finish
• Marking: Marking code
• Packaging: Tape and Reel

Applications

• Telecommunication, Networking Equipment
• Office Automation Equipment
• Industrial Equipment
• White Goods
• Consumer Products HS2950P 29V 5A Load Protection HotSwitch® with Adjustable OVP , OCP and SS

Description

The HS2950P is a high side HotSwitch® for a variety of load conditions in industrial, telecom and consumer applications. It features a wide input voltage range of 2.7V to 29V and is capable of providing up to 5A output current. The HS2950P utilizes flexible and programmable protection features and is able to handle multiple fault conditions. Programmable features include adjustable over current protection, precise over voltage protection, under voltage lockout, and soft start to protect against inrush currents for a range of load requirements. An adjustable turn on delay feature allows the user to sequence multiple rails and efficiently limit start up current. The automatic output discharge protects the load during fault conditions, and the HS2950P will automatically restart from fault conditions as long as over and under voltage conditions have been removed for safe operation. The HS2950P is offered in a small 3.0 x 3.0 x 0.55mm DFN

12 Lead package enabling very small board area

implementations. Schematic

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 2 of 21 Semtech Proprietary & Confidential Pin Descriptions Pin Pin Name Pin Function 1 VIN Input voltage. 2 NC No Connect Pin. 3 EN Enable input, logic high turn on power switch.

4 UVLO

Externally programmable under voltage lockout threshold. Connect UVLO to an external resistor-divider to define a threshold externally. When UVLO pin is grounded, a default position is set internally.

5 OVP

Externally programmable over voltage lockout protection. Connect OVP to an external resistor-divider to define a threshold externally. When OVP pin is grounded, a default position is set internally. 6 GND Ground connection. 7 ILIM External resistor is used to set current-limit threshold.

8 ONDLY

When ONDLY pin is OPEN as default, the delay time will be 585μs (typ). The delay time can be programmed by adding an external capacitor to this pin. There is a pull down of about 10kΩ to discharge the ONDLY cap. 9 SS When SS pin is OPEN as default, the output rise time will be 37μs. The rise time can be programmed by adding an external capacitor to this pin. To avoid excess power issues at startup, the CSS capacitor must be less than 3.3nF at 29VIN and 5A output current.

10 FLTB

Active-low open-drain output, asserted during over current (OCP), over voltage (OVP), under voltage lockout (UVLO), soft start (SS), turn on delay (ONDLY) or over temperature condition. If VOUT is turned off by enable, OVP or UVLO then the timer will be reset. If there is an OCP , FLTB will be held low while the 0.5ms timer counts. 11 VOUT Power switch output. 12 VOUT Power switch output. - Thermal Pad Both VIN and VOUT thermal pad for heat-sinking purposes. VOUT VOUT FLTB ONDLY SS ILIM VIN NC EN UVLO OVP GND VOUTVIN Pin Configuration

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 3 of 21 Semtech Proprietary & Confidential Absolute Maximum Rating Rating Symbol Value Units VIN, EN, FLTB to GND VIN , VEN ,VFLTB -0.3 to +36.0 V SS to GND VSS -0.3 to +36.0 V OVP , ILIM, ONDLY to GND -0.3 to +6.0 V UVLO to GND VUVLO -0.3 to (+6.0 or VVIN + 0.3 whichever is lower) V VOUT to GND VOUT -0.3 to (VVIN + 0.3) V ESD Protection Level(1) 2 kV Recommended Operating Conditions Rating Symbol Value Units Input Voltage VIN 2.7 to 29 V Enable Voltage VEN 0 to 29 V Maximum Output Current IO 5 A Operating Ambient Temperature TA -40 to 85 °C Thermal Information Rating Value Units Thermal Resistance, Junction to Ambient(2) 42 °C/W Maximum Junction Temperature +150 °C Storage Temperature Range -65 to +150 °C Peak IR Reflow Temperature (10s to 30s) +260 °C Exceeding the above specifications may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not recommended. NOTES: (1) Tested according to JEDEC standard JS-001-2012. (2) Calculated from package in still air, mounted to 3 x 4.5 (in), 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 4 of 21 Semtech Proprietary & Confidential

Electrical Characteristics

Unless noted otherwise, -40°C < TA < +85°C, TJ < 125°C. VIN = 29V, CIN = 10μF, COUT = 10μF, VEN = VIN. Parameter Symbol Conditions Min. Typ. Max. Units Input Voltage Range VIN 2.7 29 V Maximum Output Current IMAX 5 A Ron RON VIN>5.5V, TJ = 25°C 25 mΩVIN>5.5V, TJ = -40°C to 125°C 43 VIN<5.5V, TJ = -40°C to 125°C 50 Shutdown Current IQOFF VIN=29V, VEN=0V , VOUT = 0V 1 2.87 μA Quiescent Current IQON VIN=29V, VEN=5.5V , IOUT = 0A 340 μA EN Logic Input Enable Voltage High Level Threshold VEN-IH 2.0 V Enable Voltage Low Level Threshold VEN-UL 0.8 V Enable Input Current IEN VIN= VEN=5V 1 μA ONDLY Sourcing Current IONDLY 1.75 2.5 3.25 μA ONDLY Threshold Voltage VONDLY 0.56 0.82 1.1 V Turn On Delay Time (Default) tON_DFT EN rising edge to ONDLY peak, CONDLY = Open 255 585 800 μs Turn On Delay Time (Programmable) tON CONDLY = 10nF 4 ms Depending on CONDLY (1) 0 500 ms Output Rise Time (Default) tRT_DFT CSS=open, RILIM=20kΩ , COUT=10μF, IOUT = 0A 37 μs SS Sourcing Current ISS 60 100 140 μA Turn Off Delay tOFF 16 μs Output Fall Time tFT VIN=29V, COUT=10μF, ROUT = 100Ω 2 ms Output Pull-down Resistance RPD VOUT=29V, TJ = 25°C 1.5 kΩ Current Limit Current Limit (Programmable) ILIMIT RS Adjustable 0.5 6.5 A Over Current Limit Accuracy ITHA RILIM = 20kΩ, VOUT=0V, onset of current limit 5 5.5 6 A Over Current Response Time tOCP 7 μs ILIM Pin ILIM Pin Voltage VILIM 284 298 312 mV

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 5 of 21 Semtech Proprietary & Confidential Electrical Characteristics (continued) Parameter Symbol Conditions Min. Typ. Max. Units RILIM Out of Range High Limit RILIMH 280 kΩ RILIM Out of Range Low Limit RILIML 10 kΩ Recommended RILIM Range RILIMRANGE 15.4 200 kΩ Under Voltage Lock Out (UVLO) UVLO Voltage Threshold VUVLO VIN Rising 263 283 302 mV UVLO Hysteresis VUVLO-TH TJ = 25°C 13 mV UVLO Leakage Current IUVLO -100 100 nA UVLO Voltage (Default) VUVLO_DEF VIN Rising 2.42 2.6 2.78 V UVLO Hysteresis (Default) VUVLO_DFT_HYS 120 mV Over Voltage Protection Over Voltage Protection Threshold VOVP VIN Rising 570 600 630 mV OVP Hysteresis VOVP_HYST TJ = 25°C 21 mV OVP Leakage Current IOVP -100 100 nA OVP Voltage (Default) VOVP_DFT VIN Rising 3.60 3.80 4.00 V OVP Hysteresis (Default) VOVP_DFT_HYST 140 mV FL TB FLTB Pin Output Low Voltage VFON IFLTB = 1mA 180 mV FLTB Pin Off State Leakage Current IFOFF VFLTB = 5.5V 1 μA FLTB Pin Blanking Time tFBLK OTP(1) 2 μs OVP , 100mV overdrive 19 μs UVLO, 100mV overdrive 8 μs OCP 0.5 ms FLTB Pin De-assert Time tFDA SS 0.5 ms Thermal Shutdown Protection(1) Thermal Shutdown Threshold TSP 150 °CThermal Shutdown Threshold at ILIM TSPILIM 130 Thermal Shutdown Hysteresis THYST 30 Thermal Shutdown Delay Time TDELAY 0.5 μs (1) Test guaranteed by design

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 6 of 21 Semtech Proprietary & Confidential Electrical Characteristics (continued) Parameter Symbol Conditions Min. Typ. Max. Units Timing Characteristics Reset Time tRESET After OCP or OTP 200 ms HS2950P Block Diagram Charge Pump IN OUT E N Thermal Sensor Regulator + Ref VDD UVLO Control Logic OVP Vref OVP ILIM GND HV Schmitt SS FLTB HV Output UVLO ONDLY ENb 10KΩ ENb

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 7 of 21 Semtech Proprietary & Confidential Typical Timing Diagram VIN EN VOUT ILIM IOUT tblanking 0.5ms OCP Response Time OCP (code 1) Riding through FLTB* tblanking 0.5ms OCP (code 2) Trig OTP, ILIM induced OTP threshold 130Ԩ tRESET 200ms 7us OCP (code 3) Exceeding tblanking Time tblanking 0.5ms Reset for tRESET Note: FLTB*: the fault indication signal is connected to VIN tRESET 200ms ONDLY tON tFDA SS 585us ~ 0.5ms ~ 110% x ILIM VOUT+1V Figure (1) 50% tON VOUT VEN 50% tOFF 10% tFT 90%90% tRT 10% VONDLY Figure (2)

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 8 of 21 Semtech Proprietary & Confidential State Diagram VOUT=0 | OCP=1 VOUT=1 & OCP=0 VOUT=1 & OCP=0 & T=0.5ms VOUT=1 & OCP=0 OVP=0 & UVLO=0 & EN=1 T<0.5ms (VOUT=0 |OCP=1) & T=0.5ms OTP=1 OTP=1 OVP=1 | UVLO=1 | EN=0 OTP=1 | (OCP=1 & T=0.5ms) T=200ms | OVP=1 |UVLO=1 | EN=0 OCP=0 OCP=1 Initial State FLTB=0 TRESET=1 SW=0 Fault DeAssert State FLTB=0 TRESET=0 SW=1 Normal Op’n State FLTB=1 TRESET=1 SW=1 StartUp State FLTB=0 TRESET=1 SW=1 T<0.5ms OCP Delay State FLTB=1/0(4) TRESET=0 SW=1 T<200ms OCP/OTP Hiccup Timeout State FLTB=0 TRESET=0 SW=0 T<0.5ms OCP Delay State FLTB=0 TRESET=0 SW=1 OTP=1 OTP=1 (3) (1) (2) (VOUT=0 |OCP=1) & T=0.5ms(5)|OTP=1 FLTB = Fault indicative signal, 0.5ms De-assert time TRESET = Internal timer reset signal SW = Switch On/Off indicator T = timer count (1) ONDLY is just an input to the Initial State and ignored for the other states. (2) SS requires = FLTB = 0. Before releasing FLTB, it must continue to stay low for another 0.5ms which is what Fault De-assert state does. (3) Turn off the SW and report the fault immediately. (4) FLTB keeps the same value as previous state. (5) If previous state is Fault DeAssert, there is no extra 0.5ms blanking time for OCP Delay State to enter Hiccup Timeout State.

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 9 of 21 Semtech Proprietary & Confidential Typical Characteristics Startup by Enable VIN = 29V, IOUT = 3A, RILIM=18kΩ, CIN = COUT=10mF Time Scale: 10ms/div, Current Scale: 500mA/div, EN and FLTb Scale: 1V/div, VIN and VOUT Scale: 5V/div Startup by Enable VIN = 5V, IOUT = 3A, RILIM=18kΩ, CIN = COUT=10mF Time Scale: 800μs/div, Voltage Scale: 1V/div, Current Scale: 500mA/div Shut Down by Enable VIN = 5V, IOUT = 3A, RILIM=18kΩ, CIN = COUT=10mF Time Scale: 20μs/div, Voltage Scale: 1V/div, Current Scale: 500mA/div Shut Down by Enable VIN = 29V, IOUT = 3A, RILIM=18kΩ, CIN = COUT=10mF Time Scale: 40μs/div, Voltage Scale: 1V/div, Current Scale: 500mA/div Startup by Enable VIN = 5V, IOUT = 3A, RILIM=18kΩ, CIN = COUT=10mF Time Scale: 10ms/div, Voltage Scale: 1V/div, Current Scale: 500mA/div Over Current Protection VIN = 29V, IOUT = 7A, RILIM=18kΩ, CIN = COUT=10μF Time Scale: 100ms/div, Current Scale: 1A/div, FLTb Scale: 1V/div, VIN and VOUT Scale: 5V/div

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 10 of 21 Semtech Proprietary & Confidential Typical Characteristics Over Voltage Protection Mode On VIN = 29V, IOUT = 3A, RILIM=18kΩ, CIN = COUT=10μF Time Scale: 40μs/div, Current Scale: 500mA/div, FLTb Scale: 1V/div, VIN and VOUT Scale: 5V/div, OVP Scale: 100mV/div Over Voltage Protection Mode Off VIN = 29V, IOUT = 3A, RILIM=18kΩ, CIN = COUT=10μF Time Scale: 1ms/div, Current Scale: 500mA/div, FLTb Scale: 1V/div, VIN and VOUT Scale: 5V/div, OVP Scale: 100mV/div Over Current Protection VIN = 6V, IOUT = 7A, RILIM=18kΩ, CIN = COUT=10μF Time Scale: 100ms/div, Voltage Scale: 1V/div, Current Scale: 1A/div Quiescent Current On vs. Temperature EN = 5.5V, CIN = COUT=10mF, Normal Operation Shutdown Current Off vs. Temperature EN = 0V, CIN = COUT=10mF, Device in Shutdown 100 150 200 250 300 350 400 -60 -40 -20 0 20 40 60 80 100 Supply Current - IQON (µA) Temperature (°C) IQON, VIN = 2.7V IQON, VIN = 29V EN = 5.5V Device in Normal Operation 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 -60 -40 -20 0 20 40 60 80 100 Supply Current - IQOFF (µA) Temperature (°C) IQOFF, VIN = 2.7V IQOFF, VIN = 29V EN = 0V Device in Shutdown On Resistance vs. Temperature VIN = EN, CIN = COUT=10mF

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 11 of 21 Semtech Proprietary & Confidential Typical Characteristics Typcal ILIMIT vs RLIMIT ILIMIT vs. Temperature VIN = 2.7V, EN = 5V, CIN = COUT=10mF ILIMIT vs. Temperature VIN = 12V, EN = 5V, CIN = COUT=10mF ILIMIT vs. Temperature VIN = 29V, EN = 5V, CIN = COUT=10mF 0.1 10 100 Current Limit - ILIMIT (A) Current Limiting Resistor - RILIM (kΩ) 𝐼𝐼𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿[𝐴𝐴] = (0.37)(𝑉𝑉𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿[𝑚𝑚𝑉𝑉]) 𝑅𝑅𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿[𝑘𝑘Ω] -60 -40 -20 0 20 40 60 80 100 Current Limit - ILIMIT (A) Temperature (°C) RILIM = 15.4kOhm RILIM = 19.6kOhm RILIM = 32.4kOhm RILIM = 64.9kOhm RILIM = 200kOhm VIN = 2.7V, EN = 5.0V -60 -40 -20 0 20 40 60 80 100 Current Limit - ILIMIT (A) Temperature (°C) RILIM = 15.4kOhm RILIM = 19.6kOhm RILIM = 32.4kOhm RILIM = 64.9kOhm RILIM = 200kOhm VIN = 12V, EN = 5.0V -60 -40 -20 0 20 40 60 80 100 Current Limit - ILIMIT (A) Temperature (°C) RILIM = 15.4kOhm RILIM = 19.6kOhm RILIM = 32.4kOhm RILIM = 64.9kOhm RILIM = 200kOhm VIN = 29V, EN = 5.0V

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 12 of 21 Semtech Proprietary & Confidential Overview HS2950P is a high-side load switch with a wide input voltage range of 2.7V to 29V supporting up to 5A DC load current. The device features low Rdson (25mΩ, typical) and a variety of adjustable protection features. HS2950P offers functions with both default and adjustable options for Over Voltage Protection (OVP), Under Voltage Lockout (UVLO), Soft Start (SS), and Turn-On Delay (ONDLY). Thermal Shutdown (TSD) protection function is integrated, and the current limit (ILIM) pin resistor (RILIM) connection condition is constantly monitored. A fault flag output (FLTB) signal will be asserted low to report fault modes of load switch. Typical Applications Circuit Figure (4) below shows a typical circuit for a 12V application. The Over Voltage Protection Threshold is set to 12.9V. The Under Voltage Protection Threshold is set to 10.8V. The Turn On Delay is set to 4ms, and the Soft Start time is set to 0.32ms. The Over Current Protection is set to trigger at 5.5A. An explantaion on how to set each of the parameters is given in the following pages.

Application Information

VIN = 12V VIN EN Output up to 5A Enable GND ILIM OVP FLTB UVLO ONDLY SS CIN2 = 10µF ROVP1 =100kΩ ROVP2 =4.87kΩ RUVLO1 =100kΩ RUVLO2 =2.67kΩ COUT =10µF CSS = 2.7nF CONDLY = 10nF RILIM = 20kΩ CIN1 = 150µFTDS2211PTDS2211P Figure (4) HS2950P Typical Applications Circuit

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 13 of 21 Semtech Proprietary & Confidential Equation 1 determines which capacitor value to use when setting the desired turn-on delay time. When a fault condition occurs, the FSM will be reset to the initial state and tON will be executed. Once the fault condition is removed and the turn-on delay time is completed, the internal state machine starts the next phase, soft start, allowing for a controlled rise in output voltage. Soft Start (SS) HS2950P typically takes 37μs for the output voltage to rise from 0V to 29V if there is no capacitor connected between SS pin and GND. Adding a ceramic capacitor, CSS, will lengthen the soft start time, tSS, as estimated by Equation 2, where ISS is the soft start capacitor charging current, typically 100μA. The maximum soft start capacitance is 3.3nF, to protect the device from thermal damage due to high power dissipation during soft start. Once VOUT reaches the same level as VIN, the soft start phase ends. After 0.5ms (tFDA) the fault flag signal deasserts and FLTB switches from low to high, indicating that the device is ready for normal operation. Over Voltage Protection (OVP) and Under Voltage Lockout (UVLO) HS2950P turns off the switch and prevents start-up if the input voltage rises above the OVP threshold or falls below the UVLO threshold. When the OVP pin and UVLO pin are connected to GND (pin voltage ≤ 30mV typical), the default thresholds for OVP (3.8V typical) and UVLO (2.6V typical) are set internally. Input Voltage SurgeSwitchTM Protection A SurgeSwitch™ protection device is recommended on VIN. For applications above 22V a TDS3011P in parallel with a 10μF electrolytic capacitor and 1μ ceramic capacitor is recommended. For applications for up to 22V, a TDS2211P is resommended. Enable and Turn On Delay HS2950P features a high voltage enable (EN) pin. The part is enabled by pulling EN higher than 2V. When disabled, the auto-discharge function is turned on to discharge the VOUT pin to GND by 1.5KΩ internal resistance. The FLTB signal does not assert low until the device is enabled. Once enabled, a default turn-on delay time is taken for the internal supply VDD to wake-up and the Finite State Machine (FSM) to scan all protection functions, including OVP , UVLO, TSD, and RILIM conditions. A turn-on delay time default (tON_DFT) is 585μs typical. And the turn-on delay time can be adopted to extend the delay time by connecting an external capacitor, CONDLY, between ONDLY pin and GND. See Figure (5) for an illustration of the charging circuit. CONDLY[nF] = IONDLY[μA]tON[ms] VONDLY[V] (1) tSS = CSS[nF]VIN[V] ISS[μA] (2) VIN ILIMIT ICharge_COUT IOUT HS2950P Figure (5) HS2950P Charging Circuit

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 14 of 21 Semtech Proprietary & Confidential Application Information, cont. The programmable threshold option is set for both the OVP and UVLO pins by using external resistors. Equations 3 and 4 are used to set the desired thresholds, where, VINOVP is the OVP threshold for rising input voltage, VOVP is the over voltage protection threshold at the OVP pin, typically 600mV, VINUVLO is the UVLO threshold for rising input voltage, and VUVLO is under voltage protection threshold at the UVLO pin, typically 283mV. Over Current Protection (OCP) HS2950P has over current protection (OCP) during soft start and normal operation. In the event of an over current condition, HS2950P limits the load current to the limit set by an external resistor, RILIM, tied from ILIM pin to GND. A resistor with 0.1% tolerance is recommended to ensure accuracy of the current limit set by the resistor. The OCP threshold ranges from 0.5A to 6.5A set by RILIM, determined by Equation 5 below. Where, ILIMIT is the typical current limit value desired to be set VILIM is the ILIM pin voltage, typically 298mV. During OCP event, the FLTB signals a fault condition. There are two scenarios for the FLTB to signal a fault under OCP . IILIM[A] = (0.37)VILIM[mV] RILIM[kΩ] (5) Figure (7) illustrates one of the scenarios in which the OCP event happens. At the time t=t2, the output current iOUT exceeds the OCP limit threshold i2 programmed by the RILIM, but iOUT is less than 110% of i2 . The FLTB signal remains high within the next 500ms and after if the output current stays higher than the OCP threshold i2 and lower than 110% of i2 . Another OCP scenario is shown in Figure (8) below. At time t=t2, the output current iOUT exceeds the OCP limit threshold i2 programmed by the RILIM . The output current iOUT continues ramping up exceeding 110% of i2 at i3 . The FLTB signal trips 0.5ms later when the output current exceeds i3 at t=t3 . HS2950P has an over current response time (7μs typical) after the OCP event. The picture below illustrates how the ending load current varies according to different over current slew rates, SIOUT , during the OCP event. FLTB Output Currenti0 t0 t High 110% ILIMIT FLTB iOUT t0 t ILIMIT t1 t2 Figure (7) OCP Event with Less Over-Loaded Current VINOVP[V] = VOVP ROVP1 +ROVP2 ROVP2 (3) VIN ROVP1 ROVP2 OVP Pin VIN RUVLO1 UVLO Pin RUVLO2 Figure (6) OVP and UVLO Programming Circuit Figure (8) OCP Event with Heavy Load Current VINUVLO[V] = VUVLO RUVLO1 +RUVLO2 RUVLO2 (4)

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 15 of 21 Semtech Proprietary & Confidential As shown in Figure (9) , at t0 the output voltage and the output current are v0 and i0 , respectively. The output current starts to ramps up at t1. At t2, the output current exceeds the OCP threshold i2. Due to the OCP response time, the output current continues to ramp up at the same slew rate, SIOUT , as before, until the end of the 7μs. The current i3 can be estimated using Equation 6. The current i2 is the 110% of the OCP threshold preset by the programmable resistor on the ILIM pin. Short Circuit Protection HS2950P has a short circuit protection function during soft start and normal operation, with a threshold setting 10% higher than the OCP level based on the RILIM resistor. If a short circuit event (Vout shorted to GND via a small impedance) occurs during soft start, the device is forced into Hiccup mode directly. If a short circuit event happens during normal operation, the device limits the current in the main switch within 7μs and shuts down. It will then enter Hiccup mode and restart after 200ms. Application Information, cont. Thermal Shutdown Protection (TSP) HS2950P features thermal shutdown protection to prevent part from over-heating. The device turns- off and asserts fault flag signal immediately when a junction temperature above 150⁰C is detected. Once TSP is triggered, the device enters Hiccup mode without any blanking time and stays there until junction temperatures cools down by 30⁰C. The TSP threshold will be automatically adjusted to be 130⁰C, if device is operating under the current limit and the 30⁰C hysteresis remains the same. Automatic Restart after Fault HS2950P will be set to Hiccup state, where the switch is forced to shut-off, for the following conditions: 1. HS2950P over-heats and thermal shutdown threshold is reached. 2. Current limit protection is triggered and over-current condition persists beyond 0.5ms. 3. VOUT drops to 1V below VIN and such condition persists beyond 0.5ms (ignored by soft start phase). The device stays in Hiccup for 200ms before it automatically tries to re-start. Re-start requires all fault condition to be removed and tON to be completed. FL TB Signal FLTB pin is an open drain output, and must be biased to an external voltage via a pull-up resistor. The fault flag signal is not asserted if device is disabled and the FLTB pin stays high. Once the device is enabled, the fault flag signal only releases after the part enters normal operation and FLTB pin is pulled high. During normal operation, six conditions trigger the fault flag signal to be asserted, and FLTB pin is pulled low accordingly: 1. OVP 2. UVLO 3. VILIM short or open(RILIM out of range) 4. OCP 5. Hiccup 6. OTP Figure (9) OCP with Different Over-Current Slew Rate Output Voltage Output Currenti0 t0 t1 v0 v2v1 t OCP Response Time SIOUT 110% ILIMIT ILIMIT i3 = i2 +(7μs)(SIOUT) (6)

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 16 of 21 Semtech Proprietary & Confidential In order to reduce the effects of voltage drop, noise, and bounce at the VIN pin, a filter/decoupling capacitor between VIN to GND is recommended. A 10μF and X7R ceramic capacitor is sufficient for most application conditions at 85°C ambient temperature. A 150μF or larger aluminum capacitor is recommended for a short- circuit test in order to minimize input voltage drop and to prevent device being damaged by inductance led voltage over-shoot on the input side Output Capacitor Selection A 10μF and X7R ceramic capacitor is sufficient for most application conditions at 85°C ambient. When a large output capacitor is used, a soft start capacitor and current limit resistor should be selected based on inrush current levels. This is to avoid a soft start OCP triggered Hiccup. PCB Layout Consideration An important objective of the layout is to minimize the PCB parasitic inductance. PCB parasitic inductance can affect several circuits’ performance at turn-off, loading transients, and output short circuit application conditions. Figure (10) shows three current loops during the opening or closing of the load switch. Both positive peak voltage on the input terminal and negative peak voltage on the output terminal are related to the parasitic inductance of PCB and length of external connection lead to DC power supply or electronic loading. It is important to keep positive peak voltage and negative voltage less than the absolute maximum rating of the HS2950P . An input capacitor (CIN) and an output capacitor (COUT) both need to be placed as close to the HS2950P as possible. Similarly the capacitors CONDLY and CSS as well as the resistors RILIM, RUVLO1, RUVLO2, ROVP1 and ROVP2 should be placed as close to the HS2950P possible. The ground points should be connected to the PCB ground with traces as short as possible. A schematic illustrating the parasitic inductances in the layout is shown in Figure (10). The corresponding layout is shown in Figure (11). COUT HS2950P VIN VOUT GND LPCB 10uF RL LLEA D LPCB LLEA D VDC LLEA D RUVLO1 RUVLO2 ROVP1 ROVP2 UVLO OVP LPCB LPCB LPCB -VDC CIN 10uF RILIM LPCB ILIM CSS CONDLY LPCB LPCB ONDLY SS Figure (10) Layout Schematic

Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 17 of 21 Semtech Proprietary & Confidential A negative voltage may occur on the output terminal during a short-circuit event. Negative voltage level is a product of short-circuit impedance, parasitic inductance, capacitance on the output terminal. A Schottky diode can be added to output terminal in order to minimize negative voltage. The Schottky diode should be placed close to the output capacitor with a short trace to reduce inductance. A fast transient event, e.g. surge or ESD, may occur on the input terminal. A Transient Diverting Suppressor (TDS) should be used on the VIN line to protect the device. The TDS should be placed close to the input capacitors with short traces. Power paths should be kept as short as possible and appropriately sized to withstand a minimum of double the maximum load current. The thermal pads for VIN and VOUT should be connected to as much copper area as possible on the top and bottom PCB layers. Thermal vias should be used for heat dissipation and to distribute current evenly. The GND at Pin 6 should be tied to the PCB ground plane by the shortest path possible. Top Layer VIN Top Layer VOUT Bottom Layer Connection Top Layer GND Top Layer Signal Lines Capacitor Resistor Legend CIN COUT RUVLO1 ROVP1 CSS CONDLY RILIM RUVLO2 ROVP2 Figure (11) Layout Illustration Thermal Analysis The maximum junction temperature of the load switch must be less than thermal shutdown threshold (150°C typical) during normal operation condition. Equation 7 describes how to calculate junction temperature (TJ_MAX) at 5A output loading current , 85°C ambient temperature and VIN less than 5.5V. A 0.5ms OCP blanking time and a 200ms reset time are integrated in HS2950P . Even if HS2950P operates under maximum input voltage (29V) condition with output shorted to 0V, the max average power loss is less than 0.5W. Thermal shut-down protection will not be toggled up to 85°C ambient temperature. VIN , VOUT and GND pins of HS2950P dissipate the majority of the heat generated during high power loss application conditions. A proper layout reduces higher junction temperature and prevents device damage. Thermal performance is improved by connecting both VIN and VOUT thermal exposed pads to copper planes on both input and output terminal. During a short circuit under normal operation, the HS2950P may become damaged if 0.5 Joule or higher power loss is dissipated on the device. To protect the HS2950P from damage in this condition, the soft-start capacitor should be less than 3.3nF to lower the average energy loss on the HS2950P to below 0.15 Joule. TJMAX = (IOUT)2(RON)(RθJA) + TA = 137.5℃ (7) PSC = (VIN)(ILIMIT) tFBLK tFBLK + tRESET 0.5ms + 200ms = 0.47W (8)

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Final Datasheet Rev 2.4 Revision Date 11/2/2022 www.semtech.com 20 of 21 Semtech Proprietary & Confidential Marking Code Marking for the 3.0 mm x 3.0 mm DFN 12 Lead Package : yyww = Datecode (Example: 1652) xxxx = Semtech Lot No. (Example: E901) Tape and Reel Specification

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Part Number Qty per Reel Reel Size HS2950P .M 5,000 13” HS2950P-EVB Evaluation Board HotSwitch is a registered trademark of Semtech Corporation. 2950 yyww xxxx Pin 1 Location (Towards Sprocket Holes)

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