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Toshiba ULN2003APG

What is ULN2003apg

The ULN2003APG/AFWG Series are high−voltage, high−current darlington drivers comprised of seven NPN darlington pairs. All units feature integral clamp diodes for switching inductive loads. Applications include relay, hammer, lamp and display (LED) drivers. ULN2003apg,made by toshiba, is a large current driving array. It is widely used in MCU, intelligent instrument, PLC, digital output card and other control circuits. It can directly drive the relay and other loads.This page we will show you how to use uln2003apg–ULN2003apg circuit and application,drivers and etc.

PriceAbout 0.55~0.85RMB
FunctionSingle chip microcomputer digital output card and other control circuits
  • ULN2003APG Function and Characteristic

It belongs to the high resistance and High Current Darlington tube IC, ULN2003APG and ULN2003 are the same line products. The high withstand voltage and High Current Darlington array consists of seven silicon NPN Darlington tubes.

Each pair of Darlington in ULN2003 is connected with a 2.7K base resistance, which can be connected directly to the TTL and CMOS circuits at the operating voltage of the 5V, and can directly handle the data that the standard logic buffer is required to deal with.

The ULN2003 has high working voltage, high working current, and the current can reach 500mA, and it can withstand the voltage of 50V in the closed state, and the output can also run in parallel with high load current.

The ULN2003 also has a diode that eliminates the coil back EMF and can be used to drive the relay. It is a double row 16 foot package, NPN transistor matrix, maximum driving voltage =50V, current =500mA, input voltage =5V, suitable for TTL COMS, composed of Darlington transistors. ULN is an integrated Darlington tube IC, which also integrates a diode with a coils anti electromotive force. Its output is allowed to pass through a current of 200mA, a saturation voltage drop of about VCE about 1V, and a voltage resistance of about 36V. The external load of the user outlet can be estimated based on the above parameters. The output current is large with the open circuit of the collector. Therefore, it can directly drive relays or solid state relays, or directly drive low-voltage bulbs. Usually when the microcontroller drives ULN2003, the resistance of up 2K is more suitable. At the same time, the COM pin should be suspended or connected to the power supply.

  • ULN2003APG Applications

Typical usage of the ULN2003A is in driver circuits for relays, lamp and LED displays, stepper motors, logic buffers and line drivers.

  • Precautions for Using

This IC does not include built-in protection circuits for excess current or overvoltage. If this IC is subjected to excess current or overvoltage, it may be destroyed. Hence, the utmost care must be taken when systems which incorporate this IC are designed. Utmost care is necessary in the design of the output line, COMMON and GND line since IC may be destroyed due to short−circuit between outputs, air contamination fault, or fault by improper grounding.

How to Use ULN2003APG

  • uln2003apg pinout

The function of uln2003apg pinout is as following:

uln2003apg pinout
uln2003apg pinout
The function of uln2003apg pinout table
Pin 1CPU pulse input port corresponds to a signal output terminal.
Pin 2CPU pulse input terminal.
Pin 3CPU pulse input terminal.
Pin 4CPU pulse input terminal.
Pin 5CPU pulse input terminal.
Pin 6CPU pulse input terminal.
Pin 7CPU pulse input terminal.
Pin 8grounding.
Pin 9the pin is the common end of 7 internal current diode diodes, and the positive electrodes of the diodes are connected to the collectors of Darlington tubes respectively. When used for inductive load, the foot is connected with the positive pole of the load power to realize the function of freewheeling. If the foot is grounded, it is in fact the collector of the Darlington tube is connected to the ground.
Pin 10pulse signal output, corresponding to the 7 foot signal input.
Pin 11pulse signal output, corresponding to the 6 foot signal input.
Pin 12pulse signal output, corresponding to the 5 foot signal input.
Pin 13pulse signal output, corresponding to the 4 foot signal input.
Pin 14pulse signal output, corresponding to the 3 foot signal input.
Pin 15pulse signal output, corresponding to the 2 foot signal input.
Pin 16pulse signal output, corresponding to the 1 foot signal input.
  • uln2003apg features
  1. 500mA rated collector current (single output)
  2. high voltage output: 50V
  3. compatibility of input and various logical types
  4. relay driver
  •  uln2003apg driver

Just see the following uln2003apg diagram:

uln2003apg diagram
uln2003apg diagram

As shown in the figure, the microcontroller on the left is controlled by IO, and it can be used all the way, such as IN1. On the right, the DC motor is connected to the OUT1. One end of the DC motor is connected to the OUT1 and the other end is connected to a power supply. In this way, when the IN1 is high, the OUT1 outputs a low level, which allows the motor to turn. When you want to stop, IN1 can enter 0.

 ULN2003APG Circuit

  • 1. uln2003apg Equivalent Circuits

The equivalent circuit diagrams may be simplified or some parts of them may be omitted for explanatory


  • 2. uln2003apg Test Circuits

Components in the test circuits are used only to obtain and confirm the device characteristics. These

components and circuits are not guaranteed to prevent malfunction or failure from occurring in the application equipment. 

IC Usage Considerations

  • Notes on Handling of ICs
  • (1) The absolute maximum ratings of a semiconductor device are a set of ratings that must not be exceeded, even for a moment. Do not exceed any of these ratings. Exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result injury by explosion or combustion.
  • (2) Use an appropriate power supply fuse to ensure that a large current does not continuously flow in case of over current and/or IC failure. The IC will fully break down when used under conditions that exceed its absolute maximum ratings, when the wiring is routed improperly or when an abnormal pulse noise occurs from the wiring or load, causing a large current to continuously flow and the breakdown can lead smoke or ignition. To minimize the effects of the flow of a large current in case of breakdown, appropriate settings, such as fuse capacity, fusing time and insertion circuit location, are required.
  • (3) If your design includes an inductive load such as a motor coil, incorporate a protection circuit into the design to prevent device malfunction or breakdown caused by the current resulting from the inrush current at power ON or the negative current resulting from the back electromotive force at power OFF. IC breakdown may cause injury, smoke or ignition. Use a stable power supply with ICs with built-in protection functions. If the power supply is unstable, the protection function may not operate, causing IC breakdown. IC breakdown may cause injury, smoke or ignition.
  • (4) Do not insert devices in the wrong orientation or incorrectly. Make sure that the positive and negative terminals of power supplies are connected properly. Otherwise, the current or power consumption may exceed the absolute maximum rating, and exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result injury by explosion or combustion. In addition, do not use any device that is applied the current with inserting in the wrong orientation or incorrectly even just one time.
  • (5) Carefully select external components (such as inputs and negative feedback capacitors) and load components (such as speakers), for example, power amp and regulator. If there is a large amount of leakage current such as input or negative feedback condenser, the IC output DC voltage will increase. If this output voltage is connected to a speaker with low input withstand voltage, overcurrent or IC failure can cause smoke or ignition. (The over current can cause smoke or ignition from the IC itself.) In particular, please pay attention when using a Bridge Tied Load (BTL) connection type IC that inputs output DC voltage to a speaker directly.
  • Points to Remember on Handling of ICs
  • (1) Heat Radiation Design–In using an IC with large current flow such as power amp, regulator or driver, please design the device so that heat is appropriately radiated, not to exceed the specified junction temperature (Tj) at any time and condition. These ICs generate heat even during normal use. An inadequate IC heat radiation design can lead to decrease in IC life, deterioration of IC characteristics or IC breakdown. In addition, please design the device taking into considerate the effect of IC heat radiation with peripheral components.
  • (2) Back-EMF–When a motor rotates in the reverse direction, stops or slows down abruptly, a current flow back to the motor’s power supply due to the effect of back-EMF. If the current sink capability of the power supply is small, the device’s motor power supply and output pins might be exposed to conditions beyond absolute maximum ratings. To avoid this problem, take the effect of back-EMF into consideration in system design.

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