LM393APG4 - Dual Open-Collector Comparator, 8-PDIP | Texas Instruments
N.º de pieza: LM393APG4 ✓ ActivoLM393APG4 Descripción general
A comparator is a differential amplifier whose output switches state whenever the voltage applied to its inverting input rises above or falls below the voltage on its non-inverting input. As a product type, the LM393 family sits in the hierarchy comparator -> differential comparator -> analog signal conditioning IC -> integrated circuit, and it is one of the most widely cloned analog building blocks in the industry. Because the output stage is open collector, the output node can pull only to a logic-low rail, which makes the part directly usable with pull-up resistors to any supply between 2 V and 36 V, including 3.3 V, 5 V and 24 V system levels.
Key features of the LM393APG4 include two independent comparator channels that can operate from a single supply or from split dual supplies, rail-to-rail input common-mode range as highlighted in distributor listings, and an open-collector output stage that supports wired-AND busing and level translation. The device is specified as a standard, general-purpose comparator, and the same die is offered in multiple package and temperature options under the LM393 and LM393A orderable part numbers.
Architecturally, each channel in the LM393 uses a differential input pair feeding an open-collector output stage, so the outputs are naturally slow but noise-tolerant; the design is intended for sensing thresholds rather than for high-speed signal conditioning. Because the output transistor is not driven above the low state, a pull-up resistor is mandatory, and any change in pull-up supply changes the output high level without affecting the input stage.
Typical applications include over-voltage and under-voltage protection in switching power supplies, window comparators for battery monitoring, temperature threshold detection with external sensors, zero-cross detection in AC line circuits, relay and solenoid drive, and general level translation between dissimilar logic families. Industrial control and instrumentation designs use the open-collector outputs to drive optocouplers, transistors, or LED indicators directly.
When designing around the LM393APG4, always place the pull-up resistor as close as practical to the output pin to limit stray capacitance-induced switching spikes, and note that the two channels share a common ground and a common supply pin. Because the output is open collector, the device cannot source current; any load must be referenced to the same ground as the device.
This page combines manufacturer specification details, package and pin-level guidance, drop-in replacement options, and practical design notes so that engineers can evaluate the LM393APG4 alongside modern low-power alternatives without re-reading multiple documents.
Alternativas directas para LM393APG4 — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con LM393APG4 (mismo factor de forma y huella) — difiere en Output Type, Package, RoHS Status, Comparator Type, Mounting Type.
LM393AP
✅ Sustitución directa ⚠️ Especificaciones sin verificarConsulte el precio
Ver hoja de datos →LM393APE4
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
LM393P
✅ Sustitución directa ⚠️ Especificaciones sin verificarConsulte el precio
Ver hoja de datos →LM393N
✅ Sustitución directa ⚠️ Especificaciones sin verificarConsulte el precio
Ver hoja de datos →TS393
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LM393APG4 Valores máximos y características eléctricas
| Number of Comparators | 2 |
| Comparator Type | Differential (general purpose) |
| Tipo de salida | Open-Collector, Open-Emitter |
| Rail-to-Rail Input | Yes (per distributor product description) |
| Single Supply Operating Range | 2 V to 36 V |
| Dual Supply Operating Range | Supply differential of 2 V to 36 V |
| Encapsulado | 8-PDIP (0.300 inch, 7.62 mm) |
| Recuento de pines | 8 |
| Tipo de montaje | Through-hole (DIP) |
| Device Description | IC DUAL DIFF COMPARATOR 8-DIP |
| Manufacturer | Texas Instruments |
| Orderable Part Number Suffix | G4 (RoHS-compatible green) in PDIP-8 |
| Estado RoHS | unknown |
| REACH Status | unknown |
| Automotive Qualification (AEC-Q100) | unknown |
Configuración de pines de LM393APG4
| Pin 1 | OUT1 — Comparator 1 output (open collector, requires pull-up) |
| Pin 2 | IN1- — Comparator 1 inverting input |
| Pin 3 | IN1+ — Comparator 1 non-inverting input |
| Pin 4 | GND — Ground (common to both comparator channels) |
| Pin 5 | IN2+ — Comparator 2 non-inverting input |
| Pin 6 | IN2- — Comparator 2 inverting input |
| Pin 7 | OUT2 — Comparator 2 output (open collector, requires pull-up) |
| Pin 8 | VCC — Positive supply (common to both comparator channels) |
Aplicaciones típicas
LM393APG4 es adecuado para 6 aplicacións: Power Supply Over/Under-Voltage Protection, Battery Pack Window Monitoring, Industrial 24 V Sensing and Level Translation, Temperature Threshold Detection with External Sensor, Zero-Cross and AC Line Sensing, Relay, Solenoid and LED Driver Interface.
Power Supply Over/Under-Voltage Protection
The LM393APG4 is a natural fit for supervisory circuits because its 2 V to 36 V supply rating tolerates the same rails it is protecting, and its two independent channels let one comparator watch a 5 V output while the second watches the input rail. The open-collector outputs can pull a shutdown pin, an optocoupler LED or an NPN base low to disable a switching stage or trigger a crowbar, with a single pull-up resistor per output setting the logic level of the system it drives. Because the channels share pin 4 (GND) and pin 8 (VCC), both thresholds are referenced to the same supply, which keeps the protection window tight and self-consistent. The trade-off versus a modern supervisor IC is the absence of an internal reference and hysteresis on some variants, so the reference voltage and any hysteresis network must be added externally with a divider and feedback resistor.
Recomendado
Battery Pack Window Monitoring
In a multi-cell or single-cell battery management design, the LM393APG4 can watch both the upper and lower voltage limits of the pack with its two differential channels, using divider networks from the pack terminal to the inputs and a common reference at the non-inverting pins. Tying the two open-collector outputs to a single pull-up resistor produces a wired-AND fault flag that asserts whenever either limit is crossed, which is exactly the behavior a fuel-gauge system expects. Operating from 2 V minimum supply means the comparator can run directly from a discharged cell with minimal headroom loss. The limitation to plan for is the bipolar input stage's supply current, which matters most in always-on battery applications; for those, the low-power CMOS TS393 cited as a drop-in alternative offers roughly 9 uA per channel at the cost of a reduced 2.7 V to 16 V supply ceiling.
Recomendado
Industrial 24 V Sensing and Level Translation
The LM393APG4 remains standard in 24 V industrial sensing because its 36 V maximum supply voltage and open-collector output allow a 24 V sensor signal to be compared against a low-voltage reference while the output is pulled up to a 5 V or 3.3 V logic rail, accomplishing level translation without a dedicated translator IC. The open-collector stage can also directly drive a 24 V relay coil, a PLC digital input or an optocoupler, eliminating an intermediate driver transistor. Note that both channels share the supply pin, so the reference used for comparison must be referenced to the same ground as the 24 V return. For new designs where the system runs below 16 V and current budget is tight, the CMOS TS393 offers a lower-power path in the same pinout, but for genuine 24 V industrial loops the bipolar LM393 family is the safer, more widely supported choice.
Recomendado
Temperature Threshold Detection with External Sensor
A thermistor or RTD can be monitored with one LM393APG4 channel by arranging the sensor in a divider and comparing the tap against a temperature-stable reference on the other input, while the second channel implements an independent alarm threshold or a hysteresis network. The bipolar input stage of the LM393 has a low offset relative to the millivolt-level signals typically present in thermistor dividers, which helps keep trip points repeatable over temperature. The open-collector output makes it straightforward to drive a relay, an LED indicator through a series resistor, or a fan enable stage without an additional driver. Design note: because the inputs are differential but both share the same supply, the sensor return must be tied to the comparator ground, and the pull-up resistor value determines how fast the alarm node rises when the fault clears.
Recomendado
Zero-Cross and AC Line Sensing
In mains-derived sensing circuits, the LM393APG4 is frequently used to detect the zero crossing of an AC waveform so that a triac or SCR is triggered away from the transition. Its wide input bias current and open-collector output suit the noisy environment, and the wide supply range permits operation from auxiliary rails derived from the line. Modern designs often add hysteresis with a positive feedback resistor on the non-inverting input so that slow crossings do not chatter the output. When safety or isolation matters, the open-collector output is convenient because it can drive an optocoupler LED rather than coupling mains-referenced signals directly. Always observe the maximum total supply voltage of 36 V and the 2 V minimum operating supply, and remember the outputs sink current only, so every indicator or relay path needs a pull-up resistor to the appropriate logic rail.
Recomendado
Relay, Solenoid and LED Driver Interface
The open-collector output of the LM393APG4 can sink the base current of a switching NPN transistor that drives a relay coil, solenoid, buzzer or LED bar, which lets a low-current comparator output control a much larger load without a dedicated driver IC. Because the output can only pull down, the load sits between the load supply and the collector of the switching transistor, and the comparator ground is shared with the transistor emitter. This arrangement is widely used for fault-driven disconnect circuits where the comparator output must fail safe, since an open collector leaves the load de-energized if the comparator loses its supply. Keep the switching transistor's base resistor and any flyback diode close to the device for reliability, and remember that the comparator output pins share a common ground with pin 4, so any ground offset in the loop adds directly to the threshold error.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para LM393APG4 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | LM393AP | LM393APE4 | LM393P | LM393N | TS393 |
|---|---|---|---|---|---|---|
| Package | PDIP-8 (0.300 inch, 7.62 mm) | PDIP-8 (0.300 inch, 7.62 mm) - same | PDIP-8 (0.300 inch, 7.62 mm) - same | PDIP-8 (0.300 inch, 7.62 mm) - same | PDIP-8 (0.300 inch, 7.62 mm) - same | PDIP-8 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | STMicroelectronics |
| Number of Comparators | 2 | 2 | 2 | 2 | 2 | 2 |
| Output Type | Open-Collector, Open-Emitter | Open-Collector | Open-Collector | Open-Collector | Open-Collector | Open-Drain |
| Single Supply Operating Range | 2 V to 36 V | 2 V to 36 V | 2 V to 36 V | 2 V to 36 V | 2 V to 36 V | 2.7 V to 16 V |
Diferenciadores clave
- Operates up to 36 V on a single supply, far above typical CMOS-input comparators (frente a TS393)
- Exact same-die drop-in options within the same orderable family (frente a LM393APE4)
- Open-collector output enables level translation and wired-AND fault flags (frente a TS393)
- Established, widely supported supply base for industrial programs (frente a TS393)
Notas de diseño
The most common error with the LM393APG4 is forgetting that the open-collector output cannot source current. Every output node needs a pull-up resistor to a positive rail within the 2 V to 36 V device limit, and the pull-up rail may differ from the comparator supply, which is what makes level translation to 3.3 V or 5 V logic straightforward. A second common mistake is treating the two channels as independent supplies: pins 4 and 8 are shared, so both channels must run from the same supply and the same ground return. If the sensor to be sensed is referenced to a different ground, either isolate it with an optocoupler or translate it into the comparator ground domain.
Place the pull-up resistors directly at the output pins rather than at the connector or load, because the open-collector node is high impedance whenever the transistor is off and stray capacitance plus coupled noise will otherwise create slow edges and false triggers. Keep the input traces short and away from the relay or switching stage, and route the comparator ground pin with a low-impedance path to the system ground star point so that ground bounce in the relay loop does not shift the reference seen at the inputs. Through-hole PDIP-8 placement also benefits from a solid ground pour under the device to reduce coupling into the high-impedance input nodes.
Estimated: with a 24 V supply and both channels toggling continuously, the bipolar input and output stages consume roughly 1 mA of supply current per channel based on typical LM393-class device data, giving about 50 mW of dissipation in the 8-PDIP package at 24 V. In a through-hole DIP at 25 C ambient this is far below the device power rating, so no heatsinking is required. The same calculation at a 36 V rail gives roughly 72 mW total, still thermally trivial, but the higher rail does increase the voltage stress on the internal junctions, so 36 V should be treated as the absolute ceiling rather than a nominal operating point.
Información de cumplimiento
The G4 ordering suffix on this Texas Instruments part denotes the green (RoHS-compliant) finish, but no explicit RoHS, REACH, AEC-Q100 or conflict-minerals statement was available for this orderable part number in the manufacturer or distributor pages reviewed. Treat all environmental compliance fields as unknown until the certificate of conformance for the specific lot is requested.
