[{"data":1,"prerenderedAt":352},["ShallowReactive",2],{"component:uln2003a:en":3},{"component":4,"localizationFallbackIssues":287,"related":288,"equivalentSlugs":351},{"schemaVersion":5,"governance":6,"id":18,"mpn":19,"slug":18,"primaryCategory":20,"manufacturers":21,"lifecycleStatus":23,"shortDescription":24,"deepTechnicalOverview":25,"packages":26,"absoluteMaximums":132,"recommendedOperating":141,"parametricAttributes":144,"gotchas":226,"datasheetUrl":17,"documentationSources":245,"applicationCircuits":254,"equivalents":259,"mountedOnBoards":276,"seo":277},"1.0.0",{"publication":7,"verification":10,"provenance":15},{"status":8,"publishedDate":9},"published","2026-11-03",{"status":11,"verifiedDate":9,"verifiedBy":12,"checklist":13},"verified","Gemini (independent documentary review against Texas Instruments SLRS027P Rev. P; verified pinout, PDIP-16 N and SOIC-16 D packages, absolute maximums, electrical parametric limits, gotchas, six-locale localization sidecars, and catalog release validation; owner publication GO, no physical bench signoff)",{"schema":14,"technicalFacts":14,"relationships":14,"sources":14},true,{"sourceUrls":16},[17],"https:\u002F\u002Fwww.ti.com\u002Flit\u002Fds\u002Fsymlink\u002Fuln2003a.pdf","uln2003a","ULN2003A","timer_driver",[22],"Texas Instruments","active","Texas Instruments ULN2003A 7-channel Darlington transistor array in PDIP-16 and SOIC-16; 50 V collector breakdown, 500 mA continuous sink current per channel, and integrated inductive transient suppression clamp diodes.","The ULN2003A is an industry-standard monolithic high-voltage, high-current Darlington transistor array manufactured by Texas Instruments (datasheet SLRS027P, revised February 2017). Comprising seven independent NPN Darlington pairs sharing a common emitter ground connection (Pin 8), the ULN2003A provides robust low-side sinking capability up to 500 mA continuous (600 mA peak) per channel with an off-state collector breakdown voltage rating of 50 V. Each channel incorporates an integrated 2.7 kΩ series base resistor coupled with internal base-emitter pulldown resistors, enabling direct logic interfacing to 5 V TTL, CMOS, and microcontrollers without external current-limiting passives. The device features integrated transient suppression clamp diodes sharing a common cathode terminal (Pin 9, COM); connecting Pin 9 to the positive load supply rail protects the open-collector output stages against destructive high-voltage inductive kickback spikes generated when de-energizing relays, solenoids, stepper motor coils, and inductive actuators. Outputs may be paralleled to deliver higher aggregate load currents. Standard packages include 16-pin plastic dual-in-line (PDIP-16, N package) and 16-pin small-outline integrated circuit (SOIC-16, D package), with total package power dissipation governed by thermal resistances of 67°C\u002FW and 73°C\u002FW respectively.",[27,107],{"packageType":28,"pinCount":29,"bodyDimensionsMm":30,"pitchMm":34,"thermalResistanceThetaJA":35,"pins":36},"PDIP-16",16,{"length":31,"width":32,"height":33},19.3,6.35,4.57,2.54,67,[37,43,47,51,55,59,63,67,74,79,84,88,92,96,100,104],{"pinNumber":38,"pinName":39,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":42},1,"1B","input_only","pulldown","Darlington pair 1 base input (active-high 5V TTL\u002FCMOS logic input with integrated 2.7 kΩ series base resistor)",{"pinNumber":44,"pinName":45,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":46},2,"2B","Darlington pair 2 base input (active-high 5V TTL\u002FCMOS logic input with integrated 2.7 kΩ series base resistor)",{"pinNumber":48,"pinName":49,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":50},3,"3B","Darlington pair 3 base input (active-high 5V TTL\u002FCMOS logic input with integrated 2.7 kΩ series base resistor)",{"pinNumber":52,"pinName":53,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":54},4,"4B","Darlington pair 4 base input (active-high 5V TTL\u002FCMOS logic input with integrated 2.7 kΩ series base resistor)",{"pinNumber":56,"pinName":57,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":58},5,"5B","Darlington pair 5 base input (active-high 5V TTL\u002FCMOS logic input with integrated 2.7 kΩ series base resistor)",{"pinNumber":60,"pinName":61,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":62},6,"6B","Darlington pair 6 base input (active-high 5V TTL\u002FCMOS logic input with integrated 2.7 kΩ series base resistor)",{"pinNumber":64,"pinName":65,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":66},7,"7B","Darlington pair 7 base input (active-high 5V TTL\u002FCMOS logic input with integrated 2.7 kΩ series base resistor)",{"pinNumber":68,"pinName":69,"electricalType":70,"isFiveVoltTolerant":71,"internalPull":72,"description":73},8,"E","ground",false,"none","Common emitter ground terminal for all 7 Darlington driver channels (max 2.5 A continuous return current)",{"pinNumber":75,"pinName":76,"electricalType":77,"isFiveVoltTolerant":71,"internalPull":72,"description":78},9,"COM","power_in","Common cathode terminal for integrated flyback suppression clamp diodes (must connect to load positive power supply rail when driving inductive loads)",{"pinNumber":80,"pinName":81,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":83},10,"7C","open_drain","Darlington pair 7 open-collector output (sinks up to 500 mA continuous \u002F 600 mA peak to ground; protected by clamp diode to COM)",{"pinNumber":85,"pinName":86,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":87},11,"6C","Darlington pair 6 open-collector output (sinks up to 500 mA continuous \u002F 600 mA peak to ground; protected by clamp diode to COM)",{"pinNumber":89,"pinName":90,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":91},12,"5C","Darlington pair 5 open-collector output (sinks up to 500 mA continuous \u002F 600 mA peak to ground; protected by clamp diode to COM)",{"pinNumber":93,"pinName":94,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":95},13,"4C","Darlington pair 4 open-collector output (sinks up to 500 mA continuous \u002F 600 mA peak to ground; protected by clamp diode to COM)",{"pinNumber":97,"pinName":98,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":99},14,"3C","Darlington pair 3 open-collector output (sinks up to 500 mA continuous \u002F 600 mA peak to ground; protected by clamp diode to COM)",{"pinNumber":101,"pinName":102,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":103},15,"2C","Darlington pair 2 open-collector output (sinks up to 500 mA continuous \u002F 600 mA peak to ground; protected by clamp diode to COM)",{"pinNumber":29,"pinName":105,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":106},"1C","Darlington pair 1 open-collector output (sinks up to 500 mA continuous \u002F 600 mA peak to ground; protected by clamp diode to COM)",{"packageType":108,"pinCount":29,"bodyDimensionsMm":109,"pitchMm":113,"thermalResistanceThetaJA":114,"pins":115},"SOIC-16",{"length":110,"width":111,"height":112},9.9,3.91,1.75,1.27,73,[116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131],{"pinNumber":38,"pinName":39,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":42},{"pinNumber":44,"pinName":45,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":46},{"pinNumber":48,"pinName":49,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":50},{"pinNumber":52,"pinName":53,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":54},{"pinNumber":56,"pinName":57,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":58},{"pinNumber":60,"pinName":61,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":62},{"pinNumber":64,"pinName":65,"electricalType":40,"isFiveVoltTolerant":14,"internalPull":41,"description":66},{"pinNumber":68,"pinName":69,"electricalType":70,"isFiveVoltTolerant":71,"internalPull":72,"description":73},{"pinNumber":75,"pinName":76,"electricalType":77,"isFiveVoltTolerant":71,"internalPull":72,"description":78},{"pinNumber":80,"pinName":81,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":83},{"pinNumber":85,"pinName":86,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":87},{"pinNumber":89,"pinName":90,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":91},{"pinNumber":93,"pinName":94,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":95},{"pinNumber":97,"pinName":98,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":99},{"pinNumber":101,"pinName":102,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":103},{"pinNumber":29,"pinName":105,"electricalType":82,"isFiveVoltTolerant":71,"internalPull":72,"description":106},{"supplyVoltageMaxV":133,"inputVoltageMaxV":134,"outputCurrentMaxA":135,"powerDissipationMaxW":136,"operatingTempMinC":137,"operatingTempMaxC":138,"storageTempMinC":139,"storageTempMaxC":140},50,30,0.5,1.15,-20,70,-65,150,{"supplyVoltageMinV":142,"supplyVoltageTypV":143,"supplyVoltageMaxV":133,"ambientTempMinC":137,"ambientTempMaxC":138},0,24,[145,152,157,162,168,175,181,185,190,194,200,206,210,215,220],{"symbol":146,"name":147,"typicalValue":148,"maxValue":149,"unit":150,"testCondition":151},"VCE(sat)_100","Collector-Emitter Saturation Voltage (100 mA)",0.9,1.1,"V","IC = 100 mA, IB = 250 µA, TA = 25°C",{"symbol":153,"name":154,"typicalValue":149,"maxValue":155,"unit":150,"testCondition":156},"VCE(sat)_200","Collector-Emitter Saturation Voltage (200 mA)",1.3,"IC = 200 mA, IB = 350 µA, TA = 25°C",{"symbol":158,"name":159,"typicalValue":155,"maxValue":160,"unit":150,"testCondition":161},"VCE(sat)_350","Collector-Emitter Saturation Voltage (350 mA)",1.6,"IC = 350 mA, IB = 500 µA, TA = 25°C",{"symbol":163,"name":164,"typicalValue":165,"maxValue":133,"unit":166,"testCondition":167},"ICEX","Collector Cutoff Current",0.1,"µA","VCE = 50 V, IB = 0, TA = 25°C",{"symbol":169,"name":170,"typicalValue":171,"maxValue":172,"unit":173,"testCondition":174},"II(on)","On-State Input Current",0.93,1.35,"mA","VI = 3.85 V, TA = 25°C",{"symbol":176,"name":177,"typicalValue":178,"maxValue":179,"unit":150,"testCondition":180},"VI(on)_200","On-State Input Voltage (200 mA)",2.1,2.4,"VCE = 2 V, IC = 200 mA, TA = 25°C",{"symbol":182,"name":183,"typicalValue":179,"maxValue":48,"unit":150,"testCondition":184},"VI(on)_300","On-State Input Voltage (300 mA)","VCE = 2 V, IC = 300 mA, TA = 25°C",{"symbol":186,"name":187,"typicalValue":188,"maxValue":44,"unit":150,"testCondition":189},"VF","Clamp Diode Forward Voltage",1.7,"IF = 350 mA, TA = 25°C",{"symbol":191,"name":192,"typicalValue":165,"maxValue":133,"unit":166,"testCondition":193},"IR","Clamp Diode Reverse Current","VR = 50 V, TA = 25°C",{"symbol":195,"name":196,"typicalValue":197,"minValue":197,"unit":198,"testCondition":199},"hFE","DC Current Transfer Ratio",1000,"—","VCE = 2 V, IC = 150 mA, TA = 25°C",{"symbol":201,"name":202,"typicalValue":203,"maxValue":38,"unit":204,"testCondition":205},"tPLH","Turn-On Propagation Delay",0.25,"µs","VI = 3 V to 50% output low, RL = 100 Ω",{"symbol":207,"name":208,"typicalValue":203,"maxValue":38,"unit":204,"testCondition":209},"tPHL","Turn-Off Propagation Delay","VI = 3 V to 50% output high, RL = 100 Ω",{"symbol":211,"name":212,"typicalValue":101,"unit":213,"testCondition":214},"CI","Input Capacitance","pF","VI = 0, f = 1 MHz, TA = 25°C",{"symbol":216,"name":217,"typicalValue":218,"maxValue":218,"unit":173,"testCondition":219},"IC_cont","Continuous Collector Current per Channel",500,"Single channel conducting, TA = 25°C",{"symbol":221,"name":222,"typicalValue":223,"maxValue":224,"unit":173,"testCondition":225},"IE_total","Total Ground Return Current",1500,2500,"Common emitter Pin 8 return current",[227,232,236,241],{"title":228,"severity":229,"description":230,"mitigationStrategy":231},"Unconnected COM Clamp Pin (Pin 9) on Inductive Loads Causing Collector Breakdown","critical","Each driver channel incorporates an internal fast freewheeling clamp diode whose cathode connects to Pin 9 (COM) and anode to the channel collector. When switching inductive loads (relays, solenoids, stepper motor phases), collapsing magnetic fields induce high-voltage kickback transients (V = -L * di\u002Fdt). If Pin 9 is left floating or tied to an incorrect rail, these inductive spikes exceed the 50V collector-emitter breakdown rating, causing destructive avalanche breakdown of the Darlington output transistors and permanent channel failure.","Always connect Pin 9 (COM) directly to the positive power supply rail that feeds the inductive loads (e.g. +5V, +12V, or +24V). If driving purely resistive loads such as LEDs, Pin 9 may be left floating, though tying it to the positive rail provides added noise immunity.",{"title":233,"severity":229,"description":234,"mitigationStrategy":235},"Total Package Power Dissipation and Ground Lead Current Constraints","While each individual channel is rated for up to 500 mA continuous collector sink current, all 7 channels conducting simultaneously at 500 mA would require 3.5 A total return current through the single ground lead (Pin 8), exceeding the absolute maximum ground pin rating of 2.5 A. Furthermore, at high continuous current, the cumulative saturation voltage drop across all active channels dissipates significant power, quickly exceeding the package thermal rating (1.15 W at 25°C ambient, RthetaJA = 67°C\u002FW for PDIP-16, 73°C\u002FW for SOIC-16) and causing thermal runaway.","Calculate total package dissipation: P_total = sum(V_CE(sat) * I_C * DutyCycle) + sum(V_I * I_I). When driving all 7 channels continuously at 100% duty cycle, derate individual channel currents to \u003C= 150 mA to 200 mA. For heavy loads, multiplex channels, parallel adjacent outputs, or upgrade to a DMOS sink driver such as the Toshiba TBD62003A.",{"title":237,"severity":238,"description":239,"mitigationStrategy":240},"Darlington Output Saturation Voltage Drop (0.9V to 1.6V) and Load Voltage Penalty","warning","Because a Darlington pair consists of two cascaded NPN bipolar transistors where the output stage cannot saturate below V_BE2 + V_CE(sat)1, the on-state saturation voltage drop V_CE(sat) is significantly higher than a single saturated BJT or low-RDS(on) MOSFET. At 100 mA, V_CE(sat) is typically 0.9 V to 1.1 V; at 350 mA, it climbs to 1.3 V to 1.6 V. When driving low-voltage loads (such as a 5V relay coil or 3.3V indicators), this 1V+ loss deprives the load of required terminal voltage (a 5V coil receives only 3.7V to 4.1V) while dissipating continuous heat inside the IC.","Verify that inductive coils reliably pull in at reduced terminal voltage (V_LOAD = V_SUPPLY - V_CE(sat)). For 5V relays, verify that coil pick-up voltage is \u003C= 3.75V (75% of nominal). In battery-powered or 3.3V systems where a 1V drop is intolerable, replace the bipolar ULN2003A with a DMOS driver array (such as TBD62003A) exhibiting sub-ohm on-resistance.",{"title":242,"severity":238,"description":243,"mitigationStrategy":244},"3.3V Microcontroller Logic Drive Limitations (Insufficient Base Overdrive)","The ULN2003A internal 2.7 kΩ series base resistor is sized specifically for 5V TTL and CMOS logic levels. When driven from a modern 3.3V microcontroller (such as ESP32, RP2040, or STM32), the available base voltage across the two Darlington base-emitter junctions (2 * V_BE approx 1.4V to 1.7V) yields only (3.3V - 1.5V) \u002F 2.7k = 0.67 mA of base drive. While sufficient to sink light currents up to 100 mA, this reduced base current cannot drive the output stage into full saturation at heavier collector currents (300 mA to 500 mA), resulting in elevated V_CE, increased power dissipation, and excessive package heating.","For 3.3V logic systems switching heavy loads (> 150 mA per channel), use the low-voltage optimized ULN2003LV (specifically designed for 1.8V to 5V inputs) or Toshiba TBD62003A (DMOS inputs with low threshold), or buffer the 3.3V GPIOs using a 5V level shifter such as the 74HCT245 or discrete BSS138 circuit.",[246],{"title":247,"url":17,"type":248,"authority":249,"publisher":22,"documentNumber":250,"revision":251,"releaseDate":252,"language":253},"ULN200xA, ULNQ200x High-Voltage, High-Current Darlington Transistor Arrays","datasheet","primary","SLRS027P","Rev. P","2017-02","EN",[255],{"title":256,"schematicSlug":257,"topology":258},"ULN2003A 7-Channel Relay & Solenoid Inductive Load Driver","uln2003a-7-channel-relay-solenoid-driver","Seven-channel Darlington open-collector sink driver with integrated common-cathode freewheeling clamp diodes and power-rail decoupling for 12V relays, solenoids, and stepper coils.",[260,264,267,271],{"equivalentMpn":261,"manufacturer":22,"compatibilityType":262,"parameterDifferences":263},"ULN2003AN","pin_to_pin_drop_in","Exact manufacturer orderable part number for ULN2003A in standard 16-pin PDIP (N package) through-hole outline.",{"equivalentMpn":265,"manufacturer":22,"compatibilityType":262,"parameterDifferences":266},"ULN2003ADR","Exact manufacturer orderable part number for ULN2003A in 16-pin SOIC (D package) surface-mount outline on tape and reel.",{"equivalentMpn":268,"manufacturer":269,"compatibilityType":262,"parameterDifferences":270},"MC1413P","ON Semiconductor","Direct second-source pin-compatible 7-channel Darlington driver array in PDIP-16 with identical 50 V \u002F 500 mA electrical ratings.",{"equivalentMpn":272,"manufacturer":273,"compatibilityType":274,"parameterDifferences":275},"TBD62003APG","Toshiba","differing_electrical_limits","Modern BiCD DMOS 7-channel sink driver in pin-compatible DIP-16; replaces bipolar Darlington pairs with low RDS(on) DMOS transistors, virtually eliminating VCE(sat) voltage drop and heat dissipation.",[],{"canonicalUrl":278,"metaTitle":279,"metaDescription":280,"primarySearchCluster":281,"structuredDataSchema":286},"https:\u002F\u002Fcircuitbase.tech\u002Fcomponent\u002Fuln2003a","ULN2003A Darlington Driver Pinout & Specs | CircuitBase","Texas Instruments ULN2003A 7-channel Darlington driver specs: 50V breakdown, 500mA per channel, integrated clamp diodes, PDIP-16 pinout, and inductive load gotchas.",[282,283,284,285],"uln2003a pinout","uln2003a datasheet","uln2003a relay driver","uln2003a com pin","Product",null,[289,302,318,335],{"id":290,"slug":290,"mpn":291,"primaryCategory":20,"manufacturers":292,"shortDescription":293,"packages":294,"packageTypes":296,"voltage":297,"recommendedOperating":301},"l293d","L293D",[22],"Texas Instruments L293D quadruple high-current half-H driver in PDIP-16; 600 mA continuous output current per channel, 4.5 V to 36 V motor supply, and integrated inductive clamp diodes.",[295],{"packageType":28,"pinCount":29},[28],{"context":298,"min":299,"max":300,"typical":56},"supply",4.5,36,{"supplyVoltageMinV":299,"supplyVoltageTypV":56,"supplyVoltageMaxV":300},{"id":303,"slug":303,"mpn":304,"primaryCategory":20,"manufacturers":305,"shortDescription":309,"packages":310,"packageTypes":315,"voltage":316,"recommendedOperating":317},"ne555","NE555P",[22,306,307,308],"STMicroelectronics","onsemi","Diodes Incorporated","Industry-standard precision bipolar timer IC for astable multivibrators, monostable pulse generation, and PWM controllers.",[311,313],{"packageType":312,"pinCount":68},"DIP-8",{"packageType":314,"pinCount":68},"SOIC-8",[312,314],{"context":298,"min":299,"max":29,"typical":56},{"supplyVoltageMinV":299,"supplyVoltageTypV":56,"supplyVoltageMaxV":29},{"id":319,"slug":319,"mpn":320,"primaryCategory":321,"manufacturers":322,"shortDescription":323,"packages":324,"packageTypes":329,"voltage":330,"recommendedOperating":334},"74auc1g14","SN74AUC1G14DBVR","logic_ic",[22],"Single inverting Schmitt-trigger gate in Texas Instruments Advanced Ultra-Low-Voltage CMOS (AUC) technology, operating from 0.8 V to 2.7 V with 3.6 V tolerant inputs and partial-power-down Ioff support.",[325,327],{"packageType":326,"pinCount":56},"SOT-23-5",{"packageType":328,"pinCount":56},"SC-70-5",[326,328],{"context":298,"min":331,"max":332,"typical":333},0.8,2.7,1.8,{"supplyVoltageMinV":331,"supplyVoltageTypV":333,"supplyVoltageMaxV":332},{"id":336,"slug":336,"mpn":337,"primaryCategory":338,"manufacturers":339,"shortDescription":340,"packages":341,"packageTypes":346,"voltage":347,"recommendedOperating":350},"lm2596","LM2596","voltage_regulator",[22],"Step-down switching voltage regulator capable of driving a 3A load with 150 kHz fixed frequency, 40V input range, internal thermal shutdown, and cycle-by-cycle current limiting in TO-220 and TO-263 packages.",[342,344],{"packageType":343,"pinCount":56},"TO-220-5",{"packageType":345,"pinCount":56},"TO-263-5",[343,345],{"context":348,"min":299,"max":349,"typical":89},"input",40,{"supplyVoltageMinV":299,"supplyVoltageTypV":89,"supplyVoltageMaxV":349},{"ULN2003AN":18,"ULN2003ADR":18},1793836427095]