LM293P - Dual 36V Differential Comparator | Texas Instruments
料号： LM293P ✓ 量产中LM293P 概述
A differential comparator is an analog integrated circuit that compares two input voltages and changes its output state according to their relative polarity. The LM293 belongs to the comparator hierarchy, which sits within linear and mixed-signal ICs. Its open-collector outputs can sink current from a pull-up network, allowing the outputs to be wired together when wired-OR operation is required.
The principal features of the LM293P are its dual-channel architecture, differential input arrangement, wide 2 V to 36 V operating supply range, open-collector outputs, and 300 ns response time. The package is an 8-pin PDIP, providing a through-hole footprint suitable for prototypes, legacy industrial equipment, repair assemblies, and applications where leaded components are preferred.
The LM293 contains two electrically independent comparator channels. Differential inputs are presented through inverting and non-inverting pins, while the output uses an open-collector transistor capable of pulling the output node toward ground. A pull-up resistor is required to establish a high output level, and the output stage can sink current from TTL, CMOS, and other logic families within the device's stated operating limits.
Typical uses include monitoring a control or battery voltage against a reference, detecting sensor crossings, implementing overvoltage and undervoltage protection, driving relay or indicator circuits, and providing threshold-compatible interfaces between analog and digital systems. Because the device supports a wide supply range, it can also be used in industrial systems operating from conventional low-voltage DC rails.
Designers must provide the required output pull-up and verify input common-mode limits, output-current limits, and operating temperature against the manufacturer datasheet. Input protection, bypassing, and leaded-component spacing should also be considered when the LM293P is used in high-noise or high-voltage surroundings.
This page combines verified manufacturer and distributor information with package-level selection guidance, verified drop-in candidates, application use cases, and practical design notes. It is intended to help engineers identify whether the LM293P fits an existing 8-pin comparator design without confusing electrically related but mechanically different packages.
直接替换替代料： LM293P ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： LM293P （相同外形与封装尺寸） ——差异在于 Comparator Type, Package, Number of Comparators, Response Time, Supply Voltage Range.
LM393P
✅ 直接替换联系询价
查看数据手册 →LM2903P
✅ 直接替换联系询价
查看数据手册 →LM393BP
✅ 直接替换📋 参考替代料（不在目录中）
LM2903BP
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
LM193P
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
LM293P 最大额定值与电气特性
| Comparator Type | Dual differential comparator |
| Number of Channels | 2 channels |
| Supply Voltage Range | 2 V to 36 V |
| Propagation Delay | 300 ns |
| 输出类型 | Open-collector |
| Input Common-Mode Capability | Rail-to-rail |
| Temperature Grade | Industrial grade |
| Comparator Classification | Standard general-purpose comparator |
| 封装 | 8-pin PDIP |
| 安装类型 | Through-hole |
| 引脚数量 | 8 pins |
| Channel Independence | 2 independent channels |
| Logic Output Compatibility | TTL, MOS, and CMOS compatible |
LM293P 引脚配置
| 引脚 1 | OUT1 — Open-collector output for comparator channel 1 |
| 引脚 2 | IN1- — Inverting input for comparator channel 1 |
| 引脚 3 | IN1+ — Non-inverting input for comparator channel 1 |
| 引脚 4 | GND — Ground connection |
| 引脚 5 | IN2+ — Non-inverting input for comparator channel 2 |
| 引脚 6 | IN2- — Inverting input for comparator channel 2 |
| 引脚 7 | OUT2 — Open-collector output for comparator channel 2 |
| 引脚 8 | VCC — Positive supply connection |
典型应用
LM293P 适用于 6 应用s: Industrial Voltage Threshold Detection, Relay and Indicator Drive, Battery Overvoltage Protection, Sensor Signal Conditioning, Open-Collector Logic Interfacing, Legacy Equipment Repair and Retrofit.
Industrial Voltage Threshold Detection
The LM293P is suitable for comparing a process or supply voltage with a reference when the circuit must operate from a 2 V to 36 V source and respond in 300 ns. Place the measured voltage on one differential input and the reference on the other, then use the open-collector output to drive a pulled-up logic node. This arrangement supports fast overvoltage, undervoltage, and limit-state detection, although the selected reference and input network must preserve the comparator's verified common-mode operating limits.
推荐
Relay and Indicator Drive
The LM293P open-collector outputs can sink current for relay coils, lamps, or other indicators when the load current remains within the verified output rating. Install a pull-up resistor on each output and add a flyback diode across an inductive relay coil to limit back-EMF. Compared with a push-pull logic output, the open-collector architecture provides a controlled low state and allows multiple comparator outputs to share a pulled-up node, while requiring careful transistor and load-current sizing.
推荐
Battery Overvoltage Protection
The 2 V to 36 V supply capability makes the LM293P suitable for monitoring battery-derived rails in industrial or service equipment. Compare the battery voltage against a reference to command a disconnect, alarm, or downstream inhibit signal through the open-collector output. The 300 ns propagation delay can provide a fast decision, but the complete protection system must account for reference accuracy, input protection, output pull-up selection, hysteresis, and the safe operating voltage of every attached circuit.
推荐
Sensor Signal Conditioning
The LM293P can convert a bipolar or offset sensor signal into a logic-compatible threshold event by applying the signal to one differential input and a baseline or reference to the other. Its rail-to-rail input common-mode capability is useful in systems where the signal approaches a supply rail, subject to the exact operating conditions listed in the datasheet. Add filtering for noisy sensors and consider positive feedback for hysteresis so repeated threshold crossings do not cause relay or system chatter.
推荐
Open-Collector Logic Interfacing
The LM293P open-collector output can bridge a pull-up domain to TTL, MOS, or CMOS-compatible logic, as stated in the manufacturer family documentation. Place the pull-up to the voltage required by the receiving logic and verify that the comparator's absolute maximum output voltage and sink-current capability are respected. This configuration is particularly useful for wired-OR alarm buses, because several open-collector outputs can share one pulled-up node while only asserting a low state when an event is detected.
推荐
Legacy Equipment Repair and Retrofit
The 8-pin PDIP package makes the LM293P practical for maintaining older industrial, instrumentation, and control equipment that uses through-hole dual comparators. Its 2 V to 36 V operating range and 300 ns response support general-purpose threshold functions without requiring a surface-mount redesign. During repair, confirm the original pinout, required pull-up resistor, input network, bypass capacitor, and operating temperature before substitution, because a mechanically similar package does not guarantee identical input-common-mode or output-current limits.
推荐
推荐产品汇总
工程参考数据： LM293P ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | LM393P | LM2903P | LM393BP | LM2903BP | LM193P |
|---|---|---|---|---|---|---|
| Package | 8-pin PDIP (DIP-8) | 8-pin PDIP (DIP-8) | 8-pin PDIP (DIP-8) | 8-pin PDIP (DIP-8) | 8-pin PDIP (DIP-8) | 8-pin PDIP (DIP-8) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Function | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator |
| Number of Channels | 2 channels | 2 channels | 2 channels | 2 channels | 2 channels | 2 channels |
| Logic Compatibility | TTL, MOS, and CMOS compatible | TTL, MOS, and CMOS compatible in the related TI family | TTL, MOS, and CMOS compatible in the related TI family | TTL, MOS, and CMOS compatible | TTL, MOS, and CMOS compatible | TTL, MOS, and CMOS compatible in the related TI family |
关键差异点
- Exact legacy LM293 family device in a repair-friendly PDIP package （对比 LM393BP)
- Wide verified supply operating range （对比 LM193P)
- General-purpose dual channel with independent outputs （对比 LM2903P)
- Verified 300 ns response specification （对比 LM393P)
设计说明
Place the required pull-up resistor from each open-collector output to the logic rail used by the receiving device. Select it so that the maximum high-state leakage, the lowest permitted sink current, and the required output rise time remain compatible. Because the output cannot source current, omitting the pull-up leaves the node floating. Decouple the VCC pin close to the device with the value recommended by the manufacturer datasheet.
Route comparator inputs away from switching nodes, relay-coil wiring, and other high-current paths to reduce noise-induced threshold errors. Keep the input resistors or reference network close to the relevant pins, and route the open-collector output away from sensitive analog inputs where practical. For through-hole assembly, provide adequate lead spacing and avoid long input loops that can increase pickup of magnetic and electric fields.
Do not assume that open-collector means the output can sink unlimited current. Check the datasheet's output-current and output-voltage limits under the actual output state, temperature, supply, and load conditions. When multiple outputs are tied to a common pull-up, verify that only one channel can sink at a time or that the combined sink current remains within the allowed limit. Add a flyback diode whenever the output controls an inductive relay.
Use positive feedback or another hysteresis method when a monitored signal can cross the threshold slowly or with noise; otherwise the output may chatter and repeatedly actuate a relay or reset downstream logic. Check input common-mode limits at both temperature extremes, especially when the signal approaches a supply rail. The verified rail-to-rail description does not remove all absolute-maximum, output-voltage, or supply-decoupling requirements.
合规信息
The supplied verified data identifies an industrial-grade LM293 family device but does not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. These fields remain unknown rather than assumed.