LM393PE4 - Dual Differential Comparator | Texas Instruments
MPN: LM393PE4 ✓ ActiveLM393PE4 Overview
A differential comparator is an analog signal-conditioning IC that compares two input voltages and produces a digital logic state indicating which input is higher. As part of the broader amplifier IC and comparator hierarchy, the LM393PE4 is used to perform threshold detection, level translation, sensing, window comparison, and open-drain signaling in industrial, automotive, and consumer electronics systems.
The LM393 family provides low input bias current of 3.5 nA, supply current of 200 µA per comparator, and a response time of 1 µs. Its open-collector outputs allow the output voltage to be pulled up to an external supply and permit multiple outputs to be wired together when the application requires a wired-AND function. A high-battery human body model ESD rating of 2 kV supports robust handling in conventional equipment.
Each of the two comparator sections can operate from the same supply or from independently arranged positive and negative rails. The standard LM393PE4 is the original LM393-family device, while improved LM393B variants provide lower offset voltage, lower bias current, lower supply current, faster response, and an expanded 38 V maximum rating. Pin-compatible B-version devices can therefore replace suitable original-grade devices without changing the printed circuit board.
Typical applications include DC voltage threshold detection, overvoltage and undervoltage monitoring, temperature-probe interfacing, battery supervision, window comparators, relay or solenoid drivers, and logic-level translation. The open-collector outputs are particularly useful where the required output voltage differs from the comparator supply voltage or where several devices must share a wired bus.
Designers should account for the output pull-up network, input common-mode range, supply bypass capacitors, and the voltage-current limits of each open-collector transistor. The external pull-up resistor determines output rise time and low-level sink current, while board layout should keep comparator inputs away from switching nodes and high-current output paths to limit pickup of switching noise.
This product page combines manufacturer specifications, a normalized pin description, drop-in replacement options, application guidance, and design-focused selection criteria. These resources help engineers distinguish the original LM393PE4 from improved or alternate manufacturer variants while confirming package, electrical, and application compatibility before a PCB design is released.
Drop-in alternatives for LM393PE4 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LM393PE4 (same form factor and footprint) — differing in Package, Comparator Type, RoHS Status, Output Type, Mounting Type.
LM393P
✅ Drop-InContact for price
View Datasheet →LM393BPE4
✅ Drop-In📋 Reference alternative (not in catalog)
LM393N
✅ Drop-InContact for price
View Datasheet →LM2903N
✅ Drop-InContact for price
View Datasheet →LM293N
✅ Drop-InContact for price
View Datasheet →LM393PE4 Maximum Ratings & Electrical Characteristics
| Comparator Type | 2 independent differential comparators |
| Output Type | Open-collector |
| Supply Configuration | Single supply or dual supply |
| Total Supply Voltage Rating | 36 V |
| Dual-Supply Operating Range | ±18 V |
| Input Offset Voltage | 0.37 mV |
| Input Bias Current | 3.5 nA |
| Supply Current | 200 µA per comparator |
| Response Time | 1 µs |
| ESD Rating | 2 kV HBM |
| Input Common-Mode Capability | Rail-to-rail |
| Package | 8-pin PDIP |
| Mounting Type | Through-hole PCB mount |
| Delivery Format | Tube |
LM393PE4 Pin Configuration
| Pin 1 | OUT1 — Open-collector output for comparator 1 |
| Pin 2 | IN1- — Inverting input for comparator 1 |
| Pin 3 | IN1+ — Non-inverting input for comparator 1 |
| Pin 4 | GND — Ground connection |
| Pin 5 | IN2+ — Non-inverting input for comparator 2 |
| Pin 6 | IN2- — Inverting input for comparator 2 |
| Pin 7 | OUT2 — Open-collector output for comparator 2 |
| Pin 8 | VCC — Positive supply connection |
Typical Applications
LM393PE4 is suitable for 6 applications: DC Voltage Threshold Detection, Battery Undervoltage Monitoring, Temperature-Sensor Interface, Window and Limit Comparator, Relay and Solenoid Drive Interface, Logic Level Translation.
DC Voltage Threshold Detection
The LM393PE4 is appropriate for detecting whether a DC voltage has crossed a programmed threshold. One input receives the sensed voltage while the other receives a reference derived from a resistor divider or precision source. Its 0.37 mV input offset and 3.5 nA input bias current help preserve accuracy in high-impedance sensing networks, while the 1 µs response time supports prompt threshold transitions. Because each open-collector output requires a pull-up, the design must select a resistor that supports the required logic-high rise time without excessive power.
Recommended
Battery Undervoltage Monitoring
LM393PE4 can monitor a battery pack against a fixed reference and assert an alert when the supply approaches its undervoltage threshold. The 200 µA supply current per comparator and 3.5 nA input bias current are useful in battery-powered equipment where every microamp contributes to standby drain. Its open-collector output can directly pull down a system-enable or fault line, or drive a low-current indicator. Design verification should include the reference accuracy, comparator input common-mode limits, battery chemistry, and the pull-up current consumed during normal operation.
Recommended
Temperature-Sensor Interface
A resistive temperature sensor can form one input of a comparator threshold network while the LM393PE4 provides a clean switching indication at the selected temperature. The low 3.5 nA input bias current minimizes loading of high-value thermistor dividers, and the 0.37 mV offset supports fine threshold resolution with suitable reference components. The 1 µs response time also permits thermal event detection without a long propagation delay. The output pull-up and any hysteresis components must be designed together to avoid chatter near the threshold.
Recommended
Window and Limit Comparator
Two LM393PE4 comparator sections can implement an upper and lower voltage window for a signal or power rail. One section detects overvoltage and the other detects undervoltage, allowing an external controller to recognize whether the measured level is inside the permitted operating range. The two independent open-collector outputs can be pulled up separately or joined as a fault signal where wired logic is appropriate. Hysteresis should be added around each reference to prevent repeated switching, and the resistor network should be calculated for the intended threshold and input bias error.
Recommended
Relay and Solenoid Drive Interface
LM393PE4 can control a relay, solenoid, or other inductive load by pulling the gate of an external N-channel MOSFET low. The comparator isolates the sensing function from the power stage, while its open-collector output provides a straightforward active-low drive arrangement. A 1 µs response time allows reasonably quick detection of system states, although relay operation requires a flyback path and adequate MOSFET voltage and current ratings. The design should include gate pull-down resistors, flyback protection, and logic state definitions that account for the open-collector output.
Recommended
Logic Level Translation
The open-collector LM393PE4 output can be pulled to a voltage selected independently of its power supply, making the device useful for bridging incompatible logic levels. The receiving device recognizes the pulled-up voltage as logic high, while the comparator transistor sinks the logic-low current. This arrangement avoids the fixed high output voltage of a push-pull comparator and supports several open-collector outputs sharing a bus. The pull-up voltage must remain within the comparator output limits, and the resistor must satisfy both rise-time and sink-current requirements.
Recommended
Recommended Products Summary
Engineering reference data for LM393PE4 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM393P | LM393BPE4 | LM393N | LM2903N | LM293N |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | onsemi | onsemi | onsemi |
| Package | PDIP-8 | PDIP-8 | PDIP-8 | PDIP-8 | PDIP-8 | PDIP-8 |
| Comparator Count | 2 | 2 | 2 | 2 | 2 | 2 |
| Output Type | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector |
Key Differentiators
- Original LM393-family identity with a 36 V total supply rating (vs LM393BPE4)
- Texas Instruments order code for the original 8-pin PDIP device (vs LM393N)
- Dual open-collector outputs in a through-hole package (vs LM2903N)
Design Notes
Do not treat the open-collector output as a push-pull logic output. Every output requires an external pull-up resistor, and that resistor determines the logic-high voltage, output rise time, and static current. Select the pull-up voltage within the output-pin rating, then calculate the maximum low-state sink current and the allowable propagation delay. If two outputs are connected together, verify that only one transistor attempts to sink current whenever the shared node is low.
Place the comparator input traces away from switching-node copper, relay contacts, inductors, and the open-collector outputs. Keep the input network and reference components close to pins 2, 3, 5, and 6 to reduce parasitic pickup, and route ground returns directly to the device ground pin. A local supply bypass capacitor is important because comparator input accuracy can be affected by supply ripple even when the input-reference voltage itself is stable.
Add hysteresis when the compared signal can cross the threshold at nearly the same voltage repeatedly. Positive feedback through a small resistor is a common method, but the resistor value must not disturb the intended threshold or load the reference network. Verify offset error, resistor tolerance, input bias current, and comparator propagation delay together. These effects determine the minimum detectable voltage change and whether the circuit will chatter near equilibrium.
Compliance Information
The LM393 family is described by the manufacturer as a commercial-grade dual comparator. No explicit RoHS, REACH, lead-free, halogen-free, or conflict-minerals statement is included for the exact LM393PE4 ordering code.