TSC TS2026 Dual-Channel Power Distribution Switch handbook
Contents
1. a a persa Vin 5V lour 500mA Switch Resistance Note 4 INZ OUT Vin 3 3V lout 500mA EM Horse owteansiion 08 CTT Ro CE EM EM Vn 3 3V lour 500mA TS2026 L Venx22 4V Supply Current R 100 C 1 F Output Turn on Delay ma see Timing Diagrams R 100 CL 1F Output Turn on Rise Time dm see Timing Diagrams R 100 CL 1F see Timing Diagrams R 100 CL 1F see Timing Diagrams Vout OV enable into Short Circuit Output Current ILimit oan short circuit Current Limit Threshold Ramped load applied to output Vout OV to lour Short Circuit Response Time Eee E EE short applied to output ay ea Vin 5V apply Vour 0V Sete To Over current Flag Response Until FLG low Delay uno fm o Until FLG low a HE Threshold a DEN EE is fo 8 NE Ven mo A Tu increasing each switch 140 96 Ts decreasing each switch 120 Ty MOE both switch Ts increasing both switch 160 96 Ti decreasing both switch 150 96 Note 1 Exceeding the absolute maximum rating may nace the device Note 2 The device is not guaranteed to function outside its operating rating Note 3 Devices are ESD sensitive Handing precautions recommended Note 4 For maintenance Rps lt 140mQ assembly to make gold conductors in diameter 50m Note 5 If there is a fault on one channel that channel will shut down wh2. scenarios Switch Enable into Short Circuit If a switch is enabled into a heavy load or short circuit the switch immediately enters into a constant current mode reducing the output voltage The FLG signal is asserted indicating an over current condition Switch Enable Applied to Enabled Output When a heavy load or short circuit is applied to an enabled switch a large transient current may flow until the current limit circuitry responds Once this occurs the device limits current to less than the short circuit current limit specification Current Limit Response Ramped Load The TS2026 current limit profile exhibits a small fold back effect of about 200mA Once this current limit threshold is exceeded the device switches into a constant current mode It is important to note that the device will supply current up to the current limit threshold Fault Flag The FLG signal is an N channel open drain MOSFET output FLG is asserted active low when either an over current or thermal shutdown condition occurs In the case of and over current condition FLG will be asserted only after the flag response delay time tp has elapsed This ensured that FLG is asserted only upon valid over current conditions and that erroneous error reporting is eliminated For example false over current condition can occur during hot plug event when a highly capacitive load is connected and causes a high transient inrush current that exceeds the current limit threshold for up
3. Cs lt General purpose power switching PDAs lt ACPI power distribution lt PC card hot swap Absolute Maximum Rating Supply Voltage Vea intemallimtea EK Internal Limited V 65 150 TS2026 1 7 2005 11 rev A CHARGE PUMP FLAG RESPONSE DELAY Pin Description Pin Number Pin Function EA Switch A Enable Input Logic compatible enable input Active high H or active low L Fault Flag A Output Active low open drain output Indicated over current or FLGA thermal shutdown conditions Over current conditions mush last longer than tp in order to assert FLGA Fault Flag B Output Active low open drain output Low Indicated over current FLGB or thermal shutdown conditions Over current conditions mush last longer than tp in order to assert FLGA ENB Switch B Enable Input Logic compatible enable input Active high H or active low OUTB Switch B Output eo Ground Input Switch and logic supply input Switch A Output Typical Application Vcc 2 7V to 5 5V Logic Controller TS2026 ON OFF OVERCURRENT OVERCURRENT ON OFF TS2026 2 7 2005 11 rev A Electrical Characteristics Vin 5V TA 25 C bold values indicate 40 C lt e lt 85 C unless noted Symbol Condition Min Typ Max TS2026 L VENAZVENBZ2 4V switch off OUT open TS2026 H VENAZVENB lt 0 8V CLAUSES on OUT open Enable Input Enable Input Hysteresis Elo A
4. O O 152026 O L TS2026 Dual Channel Power Distribution Switch Pin assignment 1 ENA 5 OUTB FOS 6 140mQ max on resistance per channel 3 FLGB 7 IN 2 7V to 5 5V operating range 4 ENB 8 OUTA Under voltage lockout General Description The TS2026 is high side MOSFET switches optimized for general purpose power distribution requiring circuit protection The TS2026 are internally current limited and have thermal shutdown that protects the device and load When a thermal shutdown fault occurs the output is latched off until the faulty load is removed Removing that load or toggling the enable input will reset the device output Both device employ soft start circuitry that minimized inrush current in application where highly capacitive loads are employed A fault status output flag is asserted during over current and thermal shutdown conditions Transient faults are internally filtered Features 140mQ max on resistance per channel Under voltage lockout 2 V to 5 5V operating range Reverse current flow blocking no body diode S00mA min continuous current per channel Logic compatible inputs Short circuit protection with thermal shutdown Soft start circuit Thermal isolated channels Low quiescent current Fault status flag with 3ms filter eliminates false assertions Ordering Information O ting T Part No RE Ing aie Package Ambient TS2026CS 20 85 C SOP 8 Applications lt USB peripherals lt Notebook P
5. en the die reaches approximately 140 C If the die reaches approximately 160 C both channels will shut down even if neither channel is in current limit Over temperature Threshold Note 5 TS2026 3 7 2005 11 rev A TSC Test Circuit Device Uner OUT Test Output Rise and Fall Time Active Low Switch Times TS2026 4 7 2005 11 rev A HE Function Description Input and Output IN is the power supply connection to the logic circuitry and the drain of the output MOSFET OUT is the source of the output MOSFET In a typical circuit current flows from IN to OUT toward the load If Vout is greater than Vin Current will flow from OUT to IN since the switch is bidirectional wnen enabled 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 gt Vin when the switch is disabled In this situation the TS2026 prevents undesirable current flow from OUT to IN Thermal Shutdown Thermal shutdown is employed to protect the device from damage should the die temperature exceed safe margins due mainly to short circuit faults Each channel employs its own thermal sensor Thermal shutdown shuts off the output MOSFET and asserts the FLG output if the die temperature reaches 140 C and the overheated channel is in current limit The over channel will be shut off Upon determining a thermal shutdown condition The TS2026 will automatically res
6. et its output when the die temperature cools down to 120 C The TS2026 output and FLG signal will continue to cycle on and off until the device is disabled or the fault is removed Figure 1 Depicts typical timing Depending on PCB layout package ambient temperature etc it may take several hundred milliseconds from the incidence of the fault to the output MOSFET being shut off This time will be shortest in the case of dead short on the output Power Dissipation The device s junction temperature depends on several factors such as the load PCB layout ambient temperature and package type Equations that can be used to calculate power dissipation of each channel and junction temperature are found below Pp Rps oN X lour Total power dissipation of the device will be the summation of PD for both channels To relate this to junction temperature the following equation can be used Ty Pp X 8a Ta Where Ty junction temperature Ta ambient temperature Oja is the thermal resistance of the package Current Sensing and Limiting The current limit threshold is preset internally The preset level prevents damage to the device and external load but still allows a minimum current of 500mA to be delivered to the load The current limit circuit senses a portion of the output MOSFET switch current The current sense resistor shown in the block diagram is virtual and has no voltage drop The reaction to an over current condition varies with three
7. to ims The FLG response delay time tp is typically 3ms Undervoltage Lockout Undervolrage lockout UVLO prevents the output MOSFET from turning on until VIN exceeds approximately 2 5V Undervoltage detection function only when the switch is enabled TS2026 5 7 2005 11 rev A short Circuit Fault VEN Load Fault VOUT Remove LMIT mm mm zm mz zm zam LOAD Therrnal IOUT Shutdown Reached VFLG delay Figure 1 TS2026 L Fault Timing TS2026 6 7 2005 11 rev A SOP 8 Mechanical Drawin MAX MIN MAX m o 7 0 7 P 580 620 0 229 0 244 R 025 050 ooo 0 019 TS2026 1 7 2005 11 rev A
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TSC TS2026 Dual Channel Power Distribution Switch handbook