TS2026CS

TS2026 Dual-Channel Power Distribution Switch Pin assignment: 1. EN A 2. FLGA 3. FLGB 4. EN B 5. OU TB 6. GND 7. IN 8. OU TA 140mΩ max. on-resistance per channel 2.7V to 5.5V operating range Under voltage lockout General Description The TS2026 is high-side MOSFET sw itches optim ized for general-purpose power dis tribu tion requiring circuit protection. The TS2026 are internally curren t limited and have therma l s hutdown that pro tects the device and load. When a therma l shutdown fault occurs, the output is la tched off until the faulty load is removed. Removing that load or toggling the enable input will reset the device output. Bo th device employ soft-sta rt circuitry that min imized in rush current in application where highly capacitive loads are employed. A fault status ou tput flag is asserted during over current and thermal shutdown conditions. Transient faults a re in ternally filtered. Features       140mΩ max. on-resistance per channel 2.7V to 5 .5V operating range 500mA min. continuous current pe r channel Short-circuit p rotection with therma l shutdown Thermal isolated channels. Fault status flag with 3ms filter elim inates fa lse assertions.      Under voltage lockout Reverse current flow blocking (no “body diode”) Logic-compatible inputs Soft-sta rt circuit Low quiescent current Ordering Information Part No. T S2 0 2 6 CS Operat ing Temp. (Ambient) -20 ~ +85 C o Package SOP-8 Applications    USB peripherals General purpose power switching ACPI power d istribution    Notebook PCs PDAs PC card hot swap Absolute Maximum Rating Supply Voltage Fault Flag Voltage Fault Flag Cu rrent Output Voltage Output Current Enable input Storage Temperatu re V IN VFLG IFLG VOUT IOUT IEN TSTG +6 +6 25 +6 Internal L imited -0.3 ~ +3 -65 ~ +150 V o V V mA o C C TS2026 1 -7 2005/11 rev. A Block Diagram Pin Description Pin Number 1 2 Pin Name ENA F L GA Pin Function Switch A Enable (Input): Logic-compatible enable input. Activ e high (H ) or active low (L ) Fault Flag A (Outpu t): Active -low, open-drain outpu t. Indicate d over current or thermal shutdown conditions. Over current conditions mush last longer than tD in order to assert FLGA Fault Flag B (Outpu t): Active -low, open-drain outpu t. Low Indicated over current or thermal shutdown conditions. Over cu rrent conditions mus h last longer than tP in order to assert FLGA Switch B Enable (Input): Logic-compatible enable input. Activ e-high (H ) or active-low Switch B (Output) Ground Input: Sw itch and logic supply input Switch A (Output) 3 4 5 6 7 8 F L GB ENB OU T B GN D IN OU T A Typical Application TS2026 2 -7 2005/11 rev. A Electrical Characteristics Vin=5V, TA = 25 C, bold values indicate -40 C ≤ TA ≤ 85 C u nless noted o o o Parameter Supply Current Symbol IDD Condition TS2026-L, VENA=VENB≥2.4V (switch off), OUT = open TS2026-H, VENA=VENB≤0.8V (switch on), OUT = open Low-to-high transition High-to-low transition VENA= 0V to 5.5V VIN= 5V, IOUT= 500mA VIN= 3.3V, IOUT= 500mA TS2026-H, VENX≤0.8V TS2026-L, VENX≥2.4V Min. ---0.8 --1 --------0.5 --1.5 TBD 2.2 2.0 -------- Typ. 0.75 100 1.7 1.455 250 0.01 1 90 100 -1.3 1.15 35 32 0.9 1.0 20 3 3 2.4 2.15 10 15 -140 120 160 150 Max. 5 160 2.4 --1 -140 160 10 5 4.9 100 100 1.25 1.25 -7 -2.7 2.5 25 40 10 ----- Units A A V V mV A pF mΩ mΩ A mS mS S S A A S mS mS V V Ω Ω A o o o o Enable Input th reshold Enable Input Hysteresis Enable Input Current Enable Input Capacitance Switch Resistance Note 4 Output Leakage Current Output Turn -on Delay Output Turn -on Rise Time Output Turn -off Delay Output Turn -off Fall T ime Short-C ircuit Output Current Current –Limit Threshold Short-C ircuit Response Time VEN IEN RDS(ON) tON tR tOFF tF ILIMIT RL=10Ω, CL=1F, see “Timing D iagrams” RL=10Ω, CL=1F, see “Timing D iagrams” RL=10Ω, CL=1F, see “Timing D iagrams” RL=10Ω, CL=1F, see “Timing D iagrams” VOUT= 0V, enable into short-circuit Ramped load applied to ou tput VOUT= 0V to IOUT= ILIMIT (short applied to outpu t) VIN=5V, apply VOUT=0V Until FLG low VIN=3.3V, apply VOUT=0V Until FLG low VIN rising VIN falling IL =10mA, VIN =5V IL =10mA, VIN =3.3V VFLAG =5V TJ increasing, each switch TJ decreasing, each switch TJ increasing, both switch TJ decreasing, both switch Over current Flag Response Delay Under voltage Lockout Threshold Error Flag Ou tput Resistance Error Flag O ff Curren t Over tempera ture Th reshold Note 5 tD C C C C Note 1. Exceeding the absolute maximum rating may damag e the device. Note 2. The device is not guaranteed to function outside its o perating ra ting. Note 3. Devices are ESD sensitive . Handing precautions recommended. Note 4. Fo r main tenance RDS≤140mΩ assembly to make gold conductors in diamete r 50m . o Note 5. If there is a fault on one channel, that channel will s hut down when the die reaches approximately 140 C. If the o die reaches approximately 160 C, bo th channels will shut do wn, even if neither channel is in current limit. TS2026 3 -7 2005/11 rev. A Test Circuit Timing Diagram Output R ise and Fall Time Active-Low Switch Times TS2026 4 -7 2005/11 rev. A Function Description Input and Output IN is the power supply connection to the logic circuitry and th e drain of the outpu t 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 greate r than VIN, current w ill flow from OUT to IN , since the switch is bidirectional when en abled. The output MOSFET and driver circuitry are also designed to allow the MOSFET source to be externa lly fo rced to a h igher voltage than the d rain (VOUT > VIN ) when the switch is disabled. In this situation, the TS2026 prevents und esirable current flow from OUT to IN . Thermal Shut down Thermal shutdown is emp loyed to pro tect the device from da mage should the die temperature exceed safe margins due mainly to short circuit faults . Each channel employs its own th ermal sensor. Thermal shutdown shuts off the output o MOSFET and asserts the FLG output if the die tempera ture reaches 140 C and the overheated channel is in current limit. The over channel will be shut off. Upon dete rmining a th ermal shutdown condition . The TS2026 will auto matically o reset its output when the die temperatu re cools down to 120 C . The TS2026 output and FLG signal will continue to cycle on and off until the device is disabled o r the fault is rem oved. Figure 1. Depicts typical timing. Depending on PCB layout, package, ambient temperatu re, e tc., it may take several hundred milliseconds from the incidence of the fault to the output M OSFET being shut o ff. This time w ill be shortest in the case of dead short on the outpu t. Power Dissipation The device’s junction tempera ture depends on several facto rs such as the load, PCB layout, ambient tempera ture and package type. Equations that can be used to calcula te power dissipation of each channel and junction temperatu re are found below. 2 PD = RDS(ON) x IOUT Total power dissipation of the device will be the summation of PD fo r both channels. To rela te this to junction temperature , the follow ing equation can be used: TJ = PD x θJA + TA W her e: TJ = junction tempera ture TA = amb ient temperature θJA = is the thermal resistance of the package Current Sensing and Limiting The current-limit threshold is p reset in ternally . The preset lev el prevents damage to the device and external load but s till allows a min imum current of 500mA to be delivered to the loa d. 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 scenarios. Switch Enable into Short-Circuit If a switch is enabled into a heavy load or short-circuit, the sw itch im mediately ente rs into a constant-current mode, reducing the output voltage. The FLG signal is asserted indic ating an over current condition. Switch Enable A pplied t o Enabled Output When a heavy load or short-circuit is applied to an enabled s witch, 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 lim it specification. Current-Limit R esponse-Ramped Load The TS2026 current-limit pro file exhibits a sma ll fold back effect of about 200mA . Once th is curren t-limit th reshold is exceeded the device switches into a constant curren t mode. It is important to note that the device will supply current up to the current-lim it threshold Fault Flag The FLG signal is an N -channel open-drain MOSFET output. FLG is asserted (active-low ) when either an over curren t or thermal shutdown condition occurs. In the case of and over current condition, FLG will be asserted only after the flag response delay time, tD, has elapsed. This ensured that FLG is asserted only upon valid over current conditions and that erroneous error reporting is elim inated. Fo r example, false ov er current condition can occur du ring hot plug event when a highly capacitive load is connected and causes a high transient in rush current that exceeds the current-lim it threshold for up to 1ms. The FLG response delay time tD is typically 3m s. Undervoltage Lockout Undervolrage lockout (UVLO ) p revents 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 Figure 1. TS2026-L Fault Timing TS2026 6 -7 2005/11 rev. A SOP-8 Mechanical Drawing SOP-8 DIMENSION DIM A B C D F G K M P R 0 MILLIMETERS MIN 4.80 3.80 1.35 0.35 0.40 0.10 o INCHES MIN 0.189 0.150 0.054 0.014 0.016 0.004 0 o MA X 5.00 4.00 1.75 0.49 1.25 0.25 7 o MA X 0.196 0.157 0.068 0.019 0.049 0.009 7 o 1.27 (typ) 0.05 (typ) 5.80 0.25 6.20 0.50 0.229 0.010 0.244 0.019 TS2026 7 -7 2005/11 rev. A