LM393PS - Dual Open-Collector Comparator | Texas Instruments
MPN: LM393PS ✓ ActiveLM393PS Overview
A comparator is an analog integrated circuit that compares two input voltages and produces a logic-level indication of their relationship. In a wider power-management hierarchy, the LM393PS belongs to the comparator family, which sits alongside amplifiers, voltage references, and analog-to-digital converters as core signal-conditioning and control building blocks. Differential comparison is especially useful when a design must determine whether a measured signal is above or below a threshold.
Each LM393PS channel provides independent access to its non-inverting and inverting inputs, while the two open-collector outputs can be used separately or, where appropriate, externally wired together. Open-collector outputs can sink current but do not actively drive a high voltage, so external pull-up resistors are normally required. This architecture is useful for wired-AND behavior, level translation, and compatibility with systems using pull-up or pull-down logic networks.
The manufacturer documentation lists features associated with the LM393 family, including a maximum rating up to 38 V, an ESD rating of 2 kV HBM, low input offset voltage of 0.37 mV, low input bias current of 3.5 nA, low supply current of 200 µA per comparator, and a response time of 1 µs. These characteristics apply to the relevant B-version family ratings identified in the manufacturer documentation and should be checked against the operating-temperature grade and exact ordering option used in a production design.
Typical applications include battery-powered threshold detection, sensor signal conditioning, industrial control logic, power-supply supervision, window-comparator circuits, and relay or LED indication. In battery-powered equipment, the low supply current helps reduce standby consumption, while the wide input-voltage capability supports a broader range of industrial supply environments. The open-collector output also permits the system designer to select the external pull-up voltage independently from the comparator supply.
A key design consideration is the input common-mode range. Although the device is described as rail-to-rail for input operation, designers should verify the exact LM393PS electrical limits and operating conditions in the Texas Instruments datasheet. Pull-up resistor values must balance low output leakage, usable sink current, rise time, and system power consumption. For new layouts, reserve the unused comparator channel for test access rather than leaving its inputs floating.
This product page organizes the LM393PS specifications, package information, application guidance, comparison parameters, and engineering notes into one design reference. It emphasizes practical decisions around input thresholds, output pull-ups, supply bypassing, unused channels, and drop-in replacement evaluation rather than repeating only the ordering-table information.
Drop-in alternatives for LM393PS — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
LM393B
✅ Drop-In📋 Reference alternative (not in catalog)
LM393PS Maximum Ratings & Electrical Characteristics
| Comparator Type | Dual differential comparator |
| Number of Channels | 2 channels |
| Output Type | Open-collector |
| Input Common-Mode Operation | Rail-to-rail |
| Product Grade | Commercial grade |
| Package | 8-pin SOIC |
| Mounting Type | Surface mount |
| Maximum Rating | Up to 38 V |
| ESD Rating | 2 kV HBM |
| Low Input Offset Voltage | 0.37 mV |
| Low Input Bias Current | 3.5 nA |
| Low Supply Current | 200 µA per comparator |
| Response Time | 1 µs |
LM393PS 8-pin soic Pin Configuration Guide
Pin configuration for LM393PS (8-pin soic package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for LM393PS.
Refer to the datasheet for full pin configuration.
Typical Applications
LM393PS is suitable for 6 applications: Battery-Powered Threshold Detection, Industrial Sensor Conditioning, Power-Supply Supervision, Relay and LED Status Control, Window Comparator, Embedded Control and Logic Interfacing.
Battery-Powered Threshold Detection
The LM393PS fits battery-powered threshold detection because it provides two independent comparator channels and the manufacturer documentation identifies low supply current of 200 µA per comparator. Connect the sensed voltage to one input and a stable threshold to the other, then use the open-collector output to indicate the comparison result. An external pull-up connects the output to the system logic supply, allowing the logic voltage to be selected independently of the comparator supply. The principal design consideration is total standby current: pull-up resistance, signal activity, and the surrounding circuit can dominate battery consumption even when each comparator itself draws only 200 µA.
Recommended
Industrial Sensor Conditioning
The LM393PS is useful for industrial sensor conditioning when a transducer produces an analog voltage that must be converted into a threshold event. Its differential inputs reduce sensitivity to common-mode voltage on wiring, while the 3.5 nA low input bias current helps avoid loading high-impedance sensor outputs. The two channels can compare upper and lower limits, creating a window-comparator function without a separate microcontroller. A 1 µs family response time supports many process-control signals, but the sensor output must stay within the LM393PS common-mode range and the final selection should account for industrial temperature and electromagnetic requirements.
Recommended
Power-Supply Supervision
The LM393PS can monitor a supply rail by comparing its voltage against a reference threshold and asserting a fault signal when the rail moves outside the intended operating region. Two channels allow separate undervoltage and overvoltage monitoring, while the open-collector output can directly support a reset, relay, or fault latch when paired with an appropriate pull-up. The family documentation identifies operation up to 38 V and a 200 µA-per-comparator supply current, making the device relevant to industrial supervision. Designers should confirm exact threshold accuracy, common-mode limits, output leakage, and the required pull-up voltage for the particular rail being monitored.
Recommended
Relay and LED Status Control
The LM393PS open-collector outputs are well suited to driving LEDs or relay interface circuits because the external pull-up determines the switched voltage and the output transistor provides the low-side connection. In a relay-control design, the comparator can detect a command or feedback level, while a suitable transistor driver handles the relay coil rather than overloading the comparator output. Using separate pull-up rails can also make the logic interface independent of the comparator supply. The design must verify output sink current, leakage current, and timing at the actual supply voltage before selecting the output resistor and downstream transistor.
Recommended
Window Comparator
The LM393PS naturally supports a two-channel window comparator for detecting whether an analog signal lies between a lower and an upper limit. Each internal comparator can compare the input against one reference, and the two open-collector outputs can be combined through pull-up resistors to produce an in-range or out-of-range indication. This arrangement is useful for battery charging, signal-range validation, and equipment protection. The practical limits are input offset, reference accuracy, input bias current, and output transition timing. Pull-ups and reference-generation components should be selected so their tolerances do not undermine the intended threshold window.
Recommended
Embedded Control and Logic Interfacing
The LM393PS can bridge an analog condition to a microcontroller or digital logic input by producing an open-collector signal that rises through an external pull-up. Two channels provide economical monitoring of two thresholds, such as a temperature range or mechanical limit. The 200 µA-per-comparator family supply current is attractive in compact embedded systems, while the 8-pin SOIC package is straightforward to route. Firmware must treat the open-collector node as active-low or active-high according to the pull-up arrangement. Designers should avoid using the comparator output as a push-pull source and should define fail-safe states for disconnected wiring or power loss.
Recommended
Recommended Products Summary
Engineering reference data for LM393PS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM393B |
|---|---|---|
| Brand | Texas Instruments | Texas Instruments |
| Package | 8-pin SOIC | 8-pin SOIC - same package |
| Comparator Channels | 2 channels | 2 channels |
| Output Type | Open-collector | Open-collector |
| Input Common-Mode Operation | Rail-to-rail | Rail-to-rail |
| Family Maximum Rating | Up to 38 V | Up to 38 V |
| ESD Rating | 2 kV HBM | 2 kV HBM |
| Low Input Offset Voltage | 0.37 mV | 0.37 mV |
| Low Input Bias Current | 3.5 nA | 3.5 nA |
| Low Supply Current | 200 µA per comparator | 200 µA per comparator |
| Response Time | 1 µs | 1 µs |
| Product Positioning | Original LM393 family ordering option | Improved B-version family |
Key Differentiators
- Two independent general-purpose comparator channels (vs LM393B)
- Open-collector interface supports flexible pull-up voltage (vs LM393B)
- Low-power operation for threshold and supervision circuits (vs LM393B)
Design Notes
Do not treat an open-collector output as a push-pull logic output. The LM393PS output transistor pulls the node down; an external pull-up resistor must establish the high state. Select that resistor using the output leakage current, required sink current, and desired rise time. If multiple open-collector outputs share a node, their individual leakage currents add and can raise the logic-low level, so confirm the worst-case bus loading.
Place the manufacturer-recommended bypass capacitor as close as practical to the supply pins and connect it to a low-impedance ground plane. The LM393 family documentation identifies low supply current of 200 µA per comparator, but input transitions, output pull-ups, and leakage can increase board-level consumption. Estimate total standby current from the comparator, pull-up paths, reference circuitry, and downstream loads rather than using the comparator specification alone.
Keep comparator input traces short and away from switching nodes, relay-contact wiring, and other high-current paths. Connect the pull-up resistor close to the output so that PCB capacitance does not excessively slow the rising edge. For sensitive threshold measurements, use a quiet ground reference and avoid routing input traces parallel to mains or motor-switching conductors.
Configure unused inputs according to the manufacturer guidance rather than allowing them to float. Floating high-impedance inputs can consume unpredictable current and create unstable output states. Before production, verify the LM393PS pin assignments, common-mode input limits, output leakage, sink-current limits, temperature grade, and exact ordering suffix in the Texas Instruments datasheet and package drawing.
Compliance Information
The manufacturer documentation identifies LM393 as a commercial-grade dual differential comparator, but the product information does not explicitly state the requested environmental, material, or automotive qualification statuses.