MIC94040/1/2/3 - Microchip Technology

1 mic94040 /1/2/328m RDSON 3A High Side Load Switchin x MLF packageMLF and MicroLeadFrame is a registered trademark of Amkor Technology , Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 2008M9999-053008-AGeneral DescriptionThe MIC94040/1/2/3 is a family of high-side load switchesdesigned to operate from to input voltage. The loadswitch pass element is an internal 28m RDSON P-channelMOSFET which enables the device to support up to 3A ofcontinuous current . Additionally, the load switch supports level control and shutdown features in a tiny 4 pin MLF mic94040 and MIC94041 feature rapid turn on, while theMIC94042 and MIC94043 provide a slew rate controlled soft-start turn-on of 100 s. The soft-start feature is provided toprevent an in-rush current event from pulling down the inputsupply MIC94041 and MIC94043 feature an active loaddischarge circuit which switches in a 200 load when theswitch is disabled to automatically discharge a capacitive active pull-down on the enable input keeps theMIC94040/1/2/3 in a default OFF state until the enable pin ispulled above Internal level shift circuitry allows lowvoltage logic signals to switch higher supply voltages.

2 Theenable voltage can be as high as and is not limited bythe input MIC94040/1/2/3 operating voltage range makes themideal for Lithium ion and NiMH/NiCad/Alkaline batterypowered systems, as well as non-battery poweredapplications. The devices provide low quiescent current andlow shutdown current to maximize battery and support documentation can be found onMicrel s web site at: 28m RDSON 3A continuous operating current x space saving 4-pin MLF package to input voltage range Internal level shift for CMOS/TTL control logic Ultra low quiescent current Micro-power shutdown current Soft-Start: MIC94042, MIC94043 Load discharge circuit: MIC94041, MIC94043 Ultra fast turn off time Junction operating temperature from -40 C to +125 CApplications Cellular phones Portable Navigation Devices (PND) Personal Media Players (PMP) Ultra Mobile PCs Portable instrumentation Other Portable applications PDAs Industrial and DataComm equipment_____Typical ApplicationMIC94040 (ultra fast turn on)MIC94042 (soft-start)MIC94041 (ultra fast turn on with auto-dsicharge)MIC94043 (soft-start with auto-discharge)Micrel, 20082M9999-053008-AOrdering InformationPart NumberPart Marking(1)FastTurn OnSoft-StartLoadDischargePackage(2)MIC94 040 YFL P4 4-Pin ( x ) MLF MIC94041 YFL P1 4-Pin ( x ) MLF MIC94042 YFL P2 4-Pin ( x ) MLF MIC94043 YFL P3 4-Pin ( x ) MLF Notes: Pin 1 Identifier symbol is.

3 Is a GREEN RoHS-compliant package. Lead finish is NiPdAu. Mold compound is Halogen ConfigurationTop View4-Pin ( ) MLF Pin DescriptionPin NumberPin NamePin Function1 VOUTD rain of P-channel should be connected to electrical of P-channel (Input): Active-high CMOS/TTL control input for switch. Internal ~2MW Pull down will be off if this pin is left , 20083M9999-053008-AAbsolute Maximum ratings (1)Input Voltage (VIN)..+6 VEnable Voltage (VEN) ..+6 VContinuous Drain current (ID) (3)TA = 25 C .. 3 ATA = 85 C .. 2 APulsed Drain current (IDP)(4).. Diode current (IS)(5).. 50mAStorage Temperature (Ts).. 55 C to +150 CESD Rating HBM(6)..3kVOperating ratings (2)Input Voltage (VIN)..+ to + Temperature (TJ).. 40 C to +125 CPackage Thermal ResistanceMLF (qJC) ..90 C/WElectrical CharacteristicsTA = 25 C, bold values indicate 40 C< TA < +85 C, unless Threshold VoltageVIN = to , ID = 250 = VEN = , ID = OPENM easured on VIN mic94040 , CurrentVIN = VEN = , ID = OPENM easured on VIN MIC94042, MIC94043710 AIENE nable Input CurrentVIN = VEN = , ID = AISHUT-QQuiescent current (shutdown)VIN = + , VEN = 0V, ID = OPENM easured on AISHUT-SWITCHOFF State Leakage CurrentVIN = + , VEN = 0V, ID = SHORTM easured on VOUT, (7) AVIN = + , ID = 100mA, VEN = VIN = + , ID = 100mA, VEN = VIN = + , ID = 100mA, VEN = VIN = + , ID = 100mA, VEN = VIN = + , ID = 100mA, VEN = RDS(ON)P-Channel Drain to Source ONResistanceVIN = + , ID = 100mA, VEN = RSHUTDOWNTurn-Off Resistance(MIC94041, MIC94043)

4 VIN = + , ITEST = 1mA, VEN = 0V250400 Notes:1. Exceeding the absolute maximum rating may damage the The device is not guaranteed to function outside its operating With thermal contact to PCB. See thermal considerations Pulse width <300 s with < 2% duty Continuous body diode current conduction (reverse conduction, VOUT to VIN) is not Devices are ESD sensitive. Handling precautions recommended. HBM (Human body model), in series with Measured on the mic94040 YFL and , 20084M9999-053008-AElectrical Characteristics (Dynamic)TA = 25 C, bold values indicate 40 C< TA < +85 C, unless = + , ID = 100mA, VEN = , stON_DLYTurn-On Delay TimeVIN = + , ID = 100mA, VEN = , MIC9404350106185 sVIN = + , ID = 100mA, VEN = , stON_RISETurn-On Rise TimeVIN = + , ID = 100mA, VEN = , MIC9404350116200 stOFF_DLYTurn-Off Delay TimeVIN = + , ID = 100mA, VEN = 0V100200nstOFF_FALLTurn-Off Fall TimeVIN = + , ID = 100mA, VEN = 0V20100nsMicrel, 20085M9999-053008-ATypical CharacteristicsMIC94040/1/2/3 MIC94040/1/2/3 MIC94040/1/2/3 mic94040 /1 MIC94042/3 mic94040 /41 MIC94042/3 MIC94042/3 mic94040 /1 Micrel, 20086M9999-053008-ATypical CharacteristicsMIC94042/3 mic94040 /1 MIC94042/3 mic94040 /1 MIC94042/3 MIC94040/1/2/3 MIC94042/3 Micrel, 20087M9999-053008-A Functional CharacteristicsMIC94040 Micrel.

5 20088M9999-053008-AMIC94041 Micrel, 20089M9999-053008-AMIC94042 Micrel, 200810M9999-053008-AMIC94043 Micrel, 200811M9999-053008-AApplication InformationPower Dissipation ConsiderationsAs with all power switches, the current rating of theswitch is limited mostly by the thermal properties of thepackage and the PCB it is mounted on. There is asimple ohms law type relationship between thermalresistance, power dissipation and temperature, whichare analogous to an electrical circuit:Figure 1. Simple Electrical CircuitFrom this simple circuit we can calculate Vx if we knowIsource, Vz and the resistor values, Rxy and Ryz usingthe equation:()VzRyzRxyIsourceVx++ =Thermal circuits can be considered using these samerules and can be drawn similarly by replacing currentsources with power dissipation (in Watts), resistancewith thermal resistance (in oC/W) and voltage sourceswith temperature (in oC).

6 Figure 2. Simple Thermal CircuitNow replacing the variables in the equation for Vx, wecan find the junction temperature (TJ) from powerdissipation, ambient temperature and the known thermalresistance of the PCB (RqCA) and the package (RqJC).TJ = PDISS x (RqJC + RqCA) + TAPDISS is calculated as ISWITCH2 x RSWmax. RqJC is found inthe operating ratings section of the datasheet and RqCA(the PCB thermal resistance) values for various PCBcopper areas is discussed in the document Designingwith Low Dropout Voltage Regulators available from theMicrel website (LDO Application Hints).Example:A switch is intended to drive a 2A load and is placed ona printed circuit board which has a ground plane area ofat least 25mm by 25mm (625mm2). The Voltage sourceis a Li-ion battery with a lower operating threshold of 3 Vand the ambient temperature of the assembly can be upto of variables:ISW = 2 AVIN = 3V to = 50oCRqJC = 90oC/W from DatasheetRqCA = 53oC/W Read from Graph in Figure 3 Figure 3.

7 Excerpt from the LDO BookPDISS = ISW2 x RSWmaxThe worst case switch resistance (RSWmax) at the lowestVIN of 3V is not available in the datasheet, so the nextlower value of VIN is @ = 90mWIf this were a figure for worst case RSWmax for 25oC, anadditional consideration is to allow for the maximumjunction temperature of 125oC, the actual worst caseresistance in this case can be 30% higher (See RDSON variance vs. temperature graph). However, 90m is themaximum over :TJ = 22 x x (90+53) + 50TJ = 101oCThis is below the maximum , 200812M9999-053008-APackage Information4-Pin ( x ) MLF Micrel, 200813M9999-053008-ASuggested Landing Pattern for 4 Pin ( x ) MLF MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USATEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB information furnished by Micrel in this data sheet is believed to be accurate and reliable.

8 However, no responsibility is assumed by Micrel for itsuse. Micrel reserves the right to change circuitry and specifications at any time without notification to the Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a productcan reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgicalimplant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. APurchaser s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser s own risk and Purchaser agrees to fullyindemnify Micrel for any damages resulting from such use or sale.

9 2008 Micrel, Incorporated.