RT mΩ, 1A Power Multiplexer. Preliminary. General Description. Features. Applications. Ordering Information. Pin Configurations

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1 0mΩ, A Power Multiplexer General Description The is a dual input single output power multiplexer specifically designed to provide seamless voltage transition between two independent power suppliers. Equipped with two low R DS(ON) NChannel MOSFETs driven by internal charge pump circuitry, the is able to deliver A output current with only 0mV voltage drop. Manual or auto switching mode is easily selected by two digital inputs and. When both and are selected high, the enters shutdown mode and consumes minimum power making it ideal suitable for battery powered equipments. A pin with open drain output is provided to indicate the switch status. A userprogrammable up to.a current limit function is available for maximum safety in various applications. The provides comprehensive protection functions, including adjustable current limit, over temperature protection, soft start function for minimum inrush current, crossconduction protection, and reverse conduction protection. These features greatly simplify power multiplexer design. The is available in TSSOP package requiring minimum board area and smallest components. Ordering Information Package Type C : TSSOP Operating Temperature Range C : Commercial Standard P : Pb Free with Commercial Standard Note : RichTek Pbfree products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC JSTD00. Suitable for use in SnPb or Pbfree soldering processes. 00%matte tin (Sn) plating. Features Adjustable Current Limiting up to.a BuiltIn (Typically 0mΩ) NChannel MOSFET Reverse Current Flow Blocking (no body diode) i.e. Output Can Be Forced Higher than Input (OffState) Low Supply Current: μa Typical at Switch on State Less than 0.μA Typical at Switch Off State Guaranteed A Continuous Load Current Wide Input Voltage Ranges:.V to.v OpenDrain Output Hot PlugIn Application (SoftStart) Thermal Shutdown Protection Smallest TSSOP Package Minimizes Board Space RoHS Compliant and 00% Lead (Pb)Free Applications LCD Monitor, LCDTV Information Appliance and SetTop Box BatteryPowered Equipment ACPI Power Distribution Motherboard & Notebook PCs Mini PCI & PCIExpress Cards PCMCIA & New Cards Pin Configurations (TOP VIEW) TSSOP VIN DS900 July 00

2 Typical Application Circuit V IN Switch Status 0.uF R R VIN C OUT R LOAD V IN 0.uF Functional Pin Description Pin Name Pin Function Power Input Voltage VIN Power Input Voltage Output Voltage Ground is an opendrain output that is HiZ if the VIN switch is ON., The truth table shown below illustrates the functionality of and. A resistor R from to sets the current limit I LIM to (00/R ). Table. Truth Table V IN >V IN 0 0 X HiZ V IN 0 No 0 V IN 0 Yes HiZ V IN 0 X 0 V IN X 0 0 Note :. X: Don t care. HiZ: High impedance node. and cannot be floating which will lead to an unknown state.. An internal MOSFET with kω R DS(ON) turns on and softly discharges the output voltage when = =. DS900 July 00

3 Test Circuits V NC 0.uF f = Hz % Duty Cycle 00 VIN uf 0.V 0.uF Test Circuit V NC 0.uF f = Hz % Duty Cycle 00 VIN uf 0.V 0.uF Test Circuit V NC 0.uF f = 0Hz 0% Duty Cycle 00 VIN C OUT 0 0.uF Test Circuit V f = 0Hz 0% Duty Cycle k 00 VIN 0.uF 0uF 0.V 0.uF Test Circuit DS900 July 00

4 Function Block Diagram VIN Q xk V f = 0 V f = 0 Internal VDD Q V TH 0.V VDD UVLO Q is OFF Charge Pump EN Charge Pump EN Q is OFF 0.V VIN UVLO UVLO Thermal Sense Control Logic >VIN Q is ON VIN DS900 July 00

5 Absolute Maximum Ratings (Note ) Input Voltage, V IN & V IN 0.V to.0v Logic Inputs Voltage, & 0.V to.0v Output Voltage, & 0.V to.0v Power Dissipation, P T A = C TSSOP 0.W Package Thermal Resistance (Note ) TSSOP, θ JA 0 C/W Junction Temperature C Lead Temperature (Soldering, 0 sec.) 0 C ESD Susceptibility (Note ) HBM (Human Body Mode) kv MM (Machine Mode) 00V Recommended Operating Conditions (Note ) Input Voltage at V IN V IN.V.V to.v V IN <.V.V to.v Input Voltage at VIN V IN.V.V to.v V IN <.V.V to.v Logic Inputs Voltage ( &) 0V to.v Storage Temperature Range C to 0 C Junction Temperature Range 0 C to C Electrical Characteristics (V IN = V IN =.V, C IN = COUT = μf, R = 00Ω, T A = C, unless otherwise specified) Power Switch Parameter Symbol Test Conditions Min Typ Max Units V IN = V IN =.V, I OUT = A 0 9 Switch On Resistance R DS(ON) V IN = V IN =.V, I OUT = A C T A C (Note ) Logic Inputs ( and ) Threshold Input Current at or 0 LogicLow Voltage V IL 0. LogicHigh Voltage V IH.0 I IL or = High, Sink Current I IH or = Low, Source Current mω V μa To be continued DS900 July 00

6 Parameter Symbol Test Conditions Min Typ Max Units Supply and Leakage Currents Quiescent Current From ( VIN) (Operating) Shut Down Current From ( VIN) (Standby) I S I S I SHDN = High, = Low ( Active), V IN = V IN =.V, I OUT = 0A = = Low (VIN Active), V IN = V IN =.V, I OUT = 0A = = High (Inactive), V IN = V IN =.V, I OUT = 0A = = High (inactive), Forward Leakage Current From (Measured from to ) I FLKG_ V IN =.V, V IN Open, = 0V (Shorted) Forward Leakage Current From VIN (Measured from to ) I FLKG_VIN Reverse Leakage Current to VINx (Measured from VINx to ) Current Limit circuit Current Limit Accuracy = = High (inactive), V IN =.V, V IN Open, = 0V (Shorted) I RLKG_VINx = = High (inactive), V INX = 0V, =.V μa 0. μa 0. μa 0. μa 0. μa I LIM_00 R = 00Ω, V IN = V IN =.V I LIM_00 R = 00Ω, V IN = V IN =.V Input Current at I CE V I(LIM) = 0V, I OUT = 0A 0 0 μa UVLO and VIN UVLO V UVLO_FAL Falling Edge.. V UVLO_RSE Rising Edge.. Internal VDD UVLO (the higher of V UVLO_FAL Falling Edge.. and VIN) V UVLO_RSE Rising Edge.. UVLO Deglitch for and VIN Falling Edge (Note ) 00 μs Reverse Conduction Blocking ΔV O (I_Block) Minimum Outputto Input Voltage Difference to Block Switching Output = = High, V INX =.V. Connect to a V supply through a series 00Ω resistor. Let = Low. Slowly decrease the supply voltage until connects to V IN. A V V 0 mv Leakage Current I LEAKAGE V O() =.V 0.0 μa Saturation Voltage V SAT I I() = ma, V IN Switch is On 0. V Deglitch Time (falling edge only) (Note ) 0 μs Thermal Shutdown Thermal Shutdown Protection T SD C Thermal Shutdown Hysteresis ΔT SD 0 C DS900 July 00

7 Note. Stresses listed as the above Absolute Maximum Ratings may cause permanent damage to the device. These are for stress ratings. 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 for extended periods may remain possibility to affect device reliability. Note. Devices are ESD sensitive. Handling precaution recommended. Note. The device is not guaranteed to function outside its operating conditions. Note. θ JA is measured in the natural convection at T A = C on a low effective thermal conductivity test board of JEDEC thermal measurement standard. Note. Performance at C T A C is assured by design. Note. The deglitch time is assured by design. DS900 July 00

8 Typical Operating Characteristics Current Limit (A) Current Limit vs. Junction Temperature = 0, = =.V R = 00Ω Junction Temperature ( C) Quiescent Current (ua) Quiescent Current vs. Input Voltage = 0, = = VIN =.V.V IOUT = 0A Input Voltage (V) RDS(ON) (mω) R DS(ON) vs. Junction Temperature = 0, = = V RDS(ON) (mω) = 0, = =.V.V R DS(ON) vs. Input Voltage Junction Temperature ( C) Output Switchover Response Input Voltage (V) Output TurnOn Response (V/Div) (V/Div) (V/Div) Refer to Test Circuits (V/Div) (V/Div) Refer to Test Circuits = 0, = 0 = V, VIN =.V (V/Div) = 0, =, = V, VIN =.V Time (ms/div) Time (ms/div) DS900 July 00

9 Output Switchover Voltage Droop Auto Switchover Voltage Droop (V/Div) (V/Div) (V/Div), COUT = uf Refer to Test Circuits (V/Div) (V/Div) Refer to Test Circuits (V/Div), C OUT = 0uF = 0, = 0, = VIN = V =, = 0, = 0V, VIN =.V Time (0μs/Div) Time (0μs/Div) DS900 July 00 9

10 Application Information The is dual input single output power multiplexer specifically designed to provide seamless voltage transition between two independent power suppliers. Equipped with two low R DS(ON) NChannel MOSFETs driven by internal charge pump circuitry, the is able to deliver A output current with only 0mV voltage drop. The provides comprehensive protection functions, including adjustable current limit, over temperature protection, soft start function for minimum inrush current, crossconduction protection, and reverse conduction protection. These features greatly simplify power multiplexer design. Manual Switching Mode The provides two logic input and for switch selection as shown in Table. The selects the manualswitching mode when the is pulled low. In this mode connects to V IN if pulled high, otherwise connects to V IN. Auto Switching Mode selects the autoswitching mode when the is pulled high and is pulled low. In this mode connects to the higher of V IN and V IN. Shutdown Mode When both and are selected high, the enters shutdown mode and consumes minimum power. An internal MOSFET with kω R DS(ON) turns on and softly discharges the output voltage in the shutdown mode. Since no body diode exists between V INX and, output voltage is allowed to be high than the input voltages in the shutdown mode. Thermal Considerations Thermal protection limits power dissipation in. When the operation junction temperature exceeds C, the OTP circuit starts the thermal shutdown function and turns the pass element off. The pass element turn on again after the junction temperature cools by 0 C. For continuous operation, do not exceed absolute maximum operation junction temperature C. The power dissipation definition in device is: P D = (V IN ) x I OUT V IN x I Q The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junction to ambient. The maximum power dissipation can be calculated by following formula: P D(MAX) = ( T J(MAX) T A ) / θ JA where T J(MAX) is the maximum operation junction temperature C, T A is the ambient temperature and the θ JA is the junction to ambient thermal resistance. For recommended operating conditions specification of, where T J(MAX) is the maximum junction temperature of the die ( C) and T A is the maximum ambient temperature. The junction to ambient thermal resistance (θ JA is layout dependent) for TSSOP package is 0 C/W on standard JEDEC thermal test board. The maximum power dissipation at T A = C can be calculated by following formula: P D(MAX) = ( C C) / 0 C/W = 0 mw (TSSOP) Switch Status Indication A pin with open drain output is provided to indicate the switch status. pin outputs high impedance if V IN is active, otherwise pin outputs low. Current Limiting The current limit circuitry prevents damage to the MOSFET switch and external load. A resistor R from to sets the current limit to 00/R and the adjustable current limiting up to. A. A setting resistor R equal to zero is not recommended as that disables current limiting. 0 DS900 July 00

11 Outline Dimension D L E E e A A A b Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A A A b D e E E L Lead TSSOP Plastic Package RICHTEK TECHNOLOGY CORP. Headquarter F, No. 0, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: ()9 Fax: () DS900 July 00 RICHTEK TECHNOLOGY CORP. Taipei Office (Marketing) F, No., Lane, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: ()99 Fax: ()99 marketing@richtek.com