Timers & Gate DriversActive

L293D

Manufacturer: Texas Instruments

Figures from the datasheet: Texas Instruments SLRS008D, rev. Rev. D, January 2016

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.

PackagesPDIP-16

Supply voltage4.5 – 36 V

Temperature range0 – 70 °C

Official Datasheet (PDF)

Technical Overview

The L293D is an industry-standard monolithic integrated quadruple high-current half-H driver manufactured by Texas Instruments (datasheet SLRS008D, revised January 2016). Designed to provide bidirectional drive capability for inductive loads such as relays, solenoids, DC motors, and bipolar stepping motors, the L293D delivers up to 600 mA continuous output current (1.2 A non-repetitive peak for tp <= 100 µs) per channel across an output supply voltage range from 4.5 V to 36 V (VCC2). Housed in a 16-pin plastic dual-in-line package (NE designation / PDIP-16), the device features four independent push-pull totem-pole driver stages arranged as two pairs. Pair 1 (channels 1 and 2) is governed by common enable pin 1,2EN (pin 1), while pair 2 (channels 3 and 4) is governed by common enable pin 3,4EN (pin 9). All logic inputs (A and EN) are high-impedance TTL-compatible stages tolerant up to 7 V, with a high-level threshold VIH of 2.3 V and low-level threshold VIL of 1.5 V, operating from a separate logic supply VCC1 (4.5 V to 7 V, nominal 5 V). Unlike the basic L293, the L293D integrates internal high-speed output clamping diodes from each output terminal to VCC2 and GND, suppressing inductive flyback spikes without requiring external discrete diode bridges. The output stages employ a Darlington NPN pulldown transistor and pseudo-Darlington NPN pullup driver, exhibiting typical saturation voltage drops of 1.4 V (high side) and 1.2 V (low side) at rated current. Pins 4, 5, 12, and 13 are internally tied directly to the copper leadframe slug, serving as both electrical ground and the primary heatsinking path to PCB ground planes.

Package Pinout & Alternate Functions

Interactive package pinout and pin mapping for PDIP-16.

Package illustration, not a dimensioned mechanical drawing.

16 / 16 pins

Pin name	Type	5V Tolerant	Alternate functions / details
1,2EN	input only	Yes	Enable driver channels 1 and 2 (active high logic input, TTL compatible up to 7 V)
1A	input only	Yes	Driver channel 1 non-inverting input (TTL compatible up to 7 V)
1Y	power out	—	Driver channel 1 output (totem-pole push-pull stage with Darlington sink and pseudo-Darlington source; internal inductive clamp diodes to VCC2 and GND)
GND	ground	—	Device ground and heatsink pin (internally tied to copper leadframe; connect to PCB ground plane with thermal vias)
GND	ground	—	Device ground and heatsink pin (internally tied to copper leadframe; connect to PCB ground plane with thermal vias)
2Y	power out	—	Driver channel 2 output (totem-pole push-pull stage with Darlington sink and pseudo-Darlington source; internal inductive clamp diodes to VCC2 and GND)
2A	input only	Yes	Driver channel 2 non-inverting input (TTL compatible up to 7 V)
VCC2	power in	—	Power supply voltage for half-H driver output stages (4.5 V to 36 V; requires low-ESR bulk and high-frequency bypass capacitance)
3,4EN	input only	Yes	Enable driver channels 3 and 4 (active high logic input, TTL compatible up to 7 V)
3A	input only	Yes	Driver channel 3 non-inverting input (TTL compatible up to 7 V)
3Y	power out	—	Driver channel 3 output (totem-pole push-pull stage with Darlington sink and pseudo-Darlington source; internal inductive clamp diodes to VCC2 and GND)
GND	ground	—	Device ground and heatsink pin (internally tied to copper leadframe; connect to PCB ground plane with thermal vias)
GND	ground	—	Device ground and heatsink pin (internally tied to copper leadframe; connect to PCB ground plane with thermal vias)
4Y	power out	—	Driver channel 4 output (totem-pole push-pull stage with Darlington sink and pseudo-Darlington source; internal inductive clamp diodes to VCC2 and GND)
4A	input only	Yes	Driver channel 4 non-inverting input (TTL compatible up to 7 V)
VCC1	power in	—	Logic supply voltage for internal control circuitry (4.5 V to 7 V, nominal 5 V; bypass with 0.1 µF ceramic capacitor to GND)

Key Specifications

Parametric attributes

Parameter	Min	Typical	Max	Unit	Test condition
High-Level Output Voltage(VOH)	VCC2 - 1.8	VCC2 - 1.4	—	V	IOH = -0.6 A, TA = 25°C
Low-Level Output Voltage(VOL)	—	1.2	1.8	V	IOL = 0.6 A, TA = 25°C
High-Level Output Clamp Diode Voltage(VOKH)	—	VCC2 + 1.3	—	V	IOK = -0.6 A, TA = 25°C
Low-Level Output Clamp Diode Voltage(VOKL)	—	1.3	—	V	IOK = 0.6 A, TA = 25°C
High-Level Input Voltage(VIH)	2.3	—	7	V	VCC1 <= 7 V
Low-Level Input Voltage(VIL)	-0.3	—	1.5	V	VCC1 <= 7 V
High-Level Input Current (A Inputs)(IIH_A)	—	0.2	100	µA	VI = 7 V, TA = 25°C
High-Level Input Current (EN Inputs)(IIH_EN)	—	0.2	10	µA	VI = 7 V, TA = 25°C
Low-Level Input Current (A Inputs)(IIL_A)	—	-3	-10	µA	VI = 0 V, TA = 25°C
Low-Level Input Current (EN Inputs)(IIL_EN)	—	-2	-100	µA	VI = 0 V, TA = 25°C
Continuous Output Current per Channel(IO_cont)	—	600	600	mA	Each channel, TA = 25°C
Peak Output Current per Channel(IO_peak)	—	1.2	1.2	A	tp <= 100 µs, non-repetitive
Logic Supply Current (Outputs Low)(ICC1)	—	35	60	mA	IO = 0, all outputs low, TA = 25°C
Driver Supply Current (Outputs High)(ICC2)	—	14	24	mA	IO = 0, all outputs high, TA = 25°C
Low-to-High Propagation Delay(tPLH)	—	800	—	ns	VCC1 = 5 V, VCC2 = 24 V, CL = 30 pF, TA = 25°C
High-to-Low Propagation Delay(tPHL)	—	400	—	ns	VCC1 = 5 V, VCC2 = 24 V, CL = 30 pF, TA = 25°C

Absolute Maximum Ratings

Max supply voltage (VDD/VCC)	36 V
Max input voltage	7 V
Max output / pin current	1200 mA
Junction temperature	0 – 70 °C
Storage temperature	-65 – 150 °C
ESD rating (HBM)	2000 V
Thermal resistance θJA (PDIP-16)	36.4 °C/W
Thermal resistance θJC (PDIP-16)	22.5 °C/W

Hardware Engineering Gotchas

Real-world hardware caveats, PCB layout constraints and silicon errata to know before manufacturing.

Critical

Large Darlington Output Saturation Drop (2.6V to 3.6V per Bridge) and Thermal Dissipation

Each half-H output stage uses a pseudo-Darlington NPN pullup driver and a Darlington NPN pulldown sink. Because bipolar Darlington pairs cannot fully saturate below two diode drops, the output stage drops approximately 1.4V to 1.8V on the high side (VOH = VCC2 - 1.4V typ) and 1.2V to 1.8V on the low side (VOL = 1.2V typ). When driving a DC motor across a full H-bridge (two half-bridges), the cumulative voltage drop across both transistors is typically 2.6V to 3.6V. At 600mA load current, this voltage penalty dissipates 1.6W to 2.2W of heat directly inside the IC package, causing rapid thermal buildup and reduced effective motor terminal voltage.

Mitigation

Account for the 2.6V to 3.6V bridge saturation loss when choosing the motor supply rail VCC2 (e.g., supply 9V to deliver 6V nominal across the motor terminals). For high-efficiency or battery-powered designs requiring low voltage drop, use modern DMOS/CMOS H-bridge drivers (such as DRV8833 or TB6612FNG) with low RDS(on).

Warning

Output Current Limit (600 mA Continuous vs L293 Non-D 1.0 A)

The L293D integrates internal output clamp diodes for transient flyback suppression, but its continuous output current is strictly rated at 600 mA per channel (1.2 A peak for tp <= 100 µs), whereas the diode-less L293 is rated at 1.0 A continuous (2.0 A peak). Attempting to operate inductive motors with stall currents exceeding 600 mA will trigger internal thermal protection, cause voltage sagging, or permanently damage the output bond wires.

Mitigation

Verify that the motor continuous running current remains below 500 mA and stall current does not exceed 1.2 A. If higher current is needed, select the diode-less L293 with external ultra-fast flyback diodes (e.g., 1N5819 Schottky), parallel adjacent half-H channels (1A+2A tied together, 1Y+2Y tied together), or step up to a dedicated higher-current driver IC.

Warning

Separation of Logic Supply (VCC1) from Motor Power Supply (VCC2)

VCC1 powers internal low-voltage TTL logic translation stages (4.5V to 7V, nominal 5V), while VCC2 supplies the high-current inductive motor outputs (4.5V to 36V). Connecting VCC1 directly to an unregulated motor power supply or omitting bypass capacitors allows heavy inductive commutation spikes and ground bounce from motor brush arcing to propagate into the logic rail, resetting microcontrollers or latching up the driver.

Mitigation

Power VCC1 from a regulated 5V rail decoupled with a 100 nF ceramic capacitor directly adjacent to pin 16. Power VCC2 from an independent motor power rail decoupled with a local 100 nF high-frequency ceramic capacitor and a 47 µF to 100 µF low-ESR electrolytic capacitor close to pin 8. Maintain a solid star ground connection at pins 4, 5, 12, and 13.

Warning

Thermal Ground Plane Heatsinking on Central Pins 4, 5, 12, and 13

Central pins 4, 5, 12, and 13 are internally connected directly to the copper leadframe of the PDIP-16 package to serve as the primary heatsinking path. In free air with no copper heatsinking, junction-to-ambient thermal resistance RthetaJA is relatively high, limiting continuous power dissipation to under 1.5W before reaching the 150°C junction limit. Leaving these pins floating or connected with thin signal traces prevents adequate heat transfer.

Mitigation

Solder all four ground pins (4, 5, 12, and 13) directly to an unfragmented PCB copper ground plane of at least 35 µm thickness with multiple solid thermal vias. Connecting these pins to a copper pour of 30 mm x 30 mm reduces RthetaJA towards 36.4°C/W, allowing up to 3W continuous dissipation at 25°C ambient.

Cross-Reference & Equivalents

Part number (MPN)	Manufacturer	Compatibility	Electrical differences / BOM considerations
L293DNE	Texas Instruments	pin to pin drop in	Exact manufacturer orderable part number for L293D in PDIP-16 package with nickel-palladium-gold (NiPdAu) lead finish.
SN754410NE	Texas Instruments	differing electrical limits	Higher continuous output current (1.0 A per channel vs 600 mA); pin-compatible PDIP-16 footprint; check revision for internal clamp diode presence.
L293B	STMicroelectronics	functional requires bom change	Higher continuous output current (1.0 A per channel); identical PDIP-16 pinout; requires external flyback clamp diodes.

Reference Circuits

L293D Dual H-Bridge DC Motor Driver

Topology: Quadruple half-H bipolar driver configured as two full H-bridges with internal clamp diodes for bidirectional DC motor and PWM speed control.

Inspect schematic Open in Web CAD Editor

Official Documentation & Cited Datasheets

Primary semiconductor vendor datasheets, errata, and application notes.

DATASHEETTexas Instruments

L293, L293D Quadruple High-Current Half-H Drivers

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Technical Overview

Package Pinout & Alternate Functions

Key Specifications

Parametric attributes

Absolute Maximum Ratings

Hardware Engineering Gotchas

Cross-Reference & Equivalents

Reference Circuits

L293D Dual H-Bridge DC Motor Driver

Official Documentation & Cited Datasheets

L293, L293D Quadruple High-Current Half-H Drivers

Help keep this page accurate

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