Part Number: UDN2987LWTR-6-T

Manufacturer: Allegro MicroSystems


Shipped from: Shenzhen/HK Warehouse

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Technical Specifications of UDN2987LWTR-6-T

Datasheet  UDN2987LWTR-6-T datasheet
Category Integrated Circuits (ICs)
Family PMIC – Power Distribution Switches, Load Drivers
Manufacturer Allegro MicroSystems, LLC
Packaging Tape & Reel (TR)
Part Status Active
Switch Type General Purpose
Number of Outputs 8
Ratio – Input:Output 1:1
Output Configuration High Side
Output Type Bipolar
Interface On/Off
Voltage – Load 4.75 V ~ 35 V
Voltage – Supply (Vcc/Vdd) Not Required
Current – Output (Max) 350mA
Rds On (Typ)
Input Type Non-Inverting
Features Status Flag
Fault Protection Current Limiting (Fixed), Over Temperature
Operating Temperature -20°C ~ 85°C (TA)
Package / Case 20-SOIC (0.295″, 7.50mm Width)
Supplier Device Package 20-SOIC W

UDN2987LWTR-6-T Introduction

The UDN2987LW-6 driver is a strong interface that can protect up to eight source outputs from too much current. This driver is often connected to relays, motors, solenoids, LEDs, and incandescent bulbs. The output transient protection or clamp diodes and thermal shutdown diodes in the UDN2987LW-6 driver can handle up to 35V. Using the latch function, In the event that the maximum channel current is exceeded, each channel can be shut off.  If the thermal shutdown is turned on, all channels are turned off. Also, the device has a common FAULT output that can be used to show that the chip is shutting down because of too much current or too much heat. This page details the UDN2987LW-6 driver’s features, benefits, ways to use it, and circuit.

UDN2987LWTR-6-T Description

The UDN2987LW-6 driver bridges low-level logic and loads like relays, motors, solenoids, LEDs, and incandescent bulbs. Some other uses could be: This device protects each of the eight source outputs from the dangers of too much current. The output transient protection or clamp diodes and thermal shutdown diodes of the device can handle voltages up to 35 V. This driver has a latch on each channel that turns it off if the maximum current through that channel is exceeded. None of the channels will work if the thermal shutdown is set off.

No matter what kind of overcurrent state the chip is in, like thermal shutdown, there is just one FAULT output used. When the OE/R input is pulled high, all the outputs will be on. If OE/R drops to a low value, all latches are cleared, and all eight outputs are turned off. The OE/R function may be important to keep floating inputs from setting off the outputs when the power is turned on. At 25 degrees Celsius and 35 volts, each of the eight outputs will consistently make more than 100 milliamperes of current on average. The overcurrent fault circuit will protect against ground short circuits with supply voltages up to 30 volts.

These inputs work with Schottky TTL, TTL, PMOS, DTL, and CMOS logic devices that use 5 V or 12 V. If the activity level isn’t high enough, the output can’t be turned on. The UDN2987LW-6 can run on a lower driver supply voltage (4.75 V), which lets you use 5 V logic, and it has a much faster TPHL (usually 200 ns) than earlier devices. Also, the UDN2987LW-6 has a lower maximum voltage for the driver supply. The UDN2987LW-6 is a small outline (SOIC-W) plastic package with 20 leads. All of the platings on the lead frames are made of matte tin, and none of the packages contain lead (Pb).

Advantages and Features

  • voltage range for drivers: 4.75 to 35 V.
  • Enable-disable output (OE/R).
  • output source current of 350 mA.
  • Protected from overcurrent.
  • ground clamp diodes inside.
  • minimum output breakdown voltage of 35 V.
  • inputs that are TTL, DTL, PMOS, or CMOS compatible.
  • Thermal Shutdown Internal (TSD).

Applications Information and Circuit Description

Like every other power integrated circuit, the UDN2987LW-6 has a rating for the most output current it can handle. This limit is set by the company that made the product. Even if it says it can handle 500 milliamperes, that doesn’t mean it can or can be used at that level. The channel output current trip point’s lowest value is –370 mA. If you try to use the channel at current levels higher than –370 mA, you may get a fault message, and the channel may shut down. The device has been tested at a maximum output current of –350 mA, and this is the maximum recommended for each driver. It protects against too much current and up to 30 volts of shorted loads. All outputs are turned on when the OE/R input is pulled high.

If OE/R is left floating or set to a low value, the latches are reset, and all outputs are turned off (internal pull-down). Remember that the reset pulse must last at least 1 s when OE/R is low. This will ensure the device keeps working safely even if it is reset while connected to a short load. No matter how the OE/R input is set, when the power comes on, the latches are also reset. The load current causes a small drop in the voltage measured across the low-value sense resistor found inside. This voltage is compared to the drop-in voltage when a constant current flows through a reference resistor.

Matching the two resistors helps eliminate errors that can happen because of how they were made or how temperature affects them. Each channel has its own set of comparators and latches built in. If the current is too high (VSENSE > VREF), the appropriate latch will be set, and only that channel will be turned off. For all of the other channels, the usual steps will be taken. The latch has a blanking delay of one millisecond, shown by the symbol blank. This stops crossover currents from switching inductive loads from accidentally triggering the latch. The output switchyard blanking durations will provide a brief current larger than the trip current in the event of an unexpected short circuit before the output driver is turned off.

If the chip’s temperature exceeds 165°C, a standard thermal shutdown will turn off all outputs. Each latch is reset when the system shuts down because of heat. When the temperature of the semiconductor reaches about 150°C, the outputs stop working (thermal hysteresis). If one of the channels gets too much current or the chip shuts down because it gets too hot, the output of the FAULT open collector is pulled low (turned on).


The UDN2987LW-6 driver is a high-performance, flexible piece of equipment with great overcurrent protection and can maintain voltages of up to 35V for various uses. The fact that it works with different types of inputs and has a latch function makes it even easier to use and more reliable.

If you want to buy the UDN2987LW-6 driver and are looking for a trustworthy electronic distributor in China, you might want to contact ICRFQ. We can help you with your electronic needs and give you high-quality items to ensure your project succeeds. Don’t miss out on the chance to make your project more effective by not using this great tool. You shouldn’t let this chance pass you by.

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