LM393DRE4 - Dual Open-Collector Comparator | Texas Instruments
MPN： LM393DRE4 ✓ 啟用中LM393DRE4 概覽
A comparator is an analog integrated circuit that compares two input voltages and changes its output state according to their relationship. The LM393 belongs to the hierarchy of dual comparator, voltage comparator, analog IC, and semiconductor. Unlike an operational amplifier with continuous linear output, a comparator is optimized for fast switching between two output states. Two independent channels allow one package to perform two threshold or protection functions.
Key characteristics include two open-collector outputs, 300 ns propagation delay, operation from 2 V to 36 V, and a supply-current drain of 0.4 mA typical per comparator. The open-collector architecture requires an external pull-up resistor because the output transistor actively pulls the output low but does not source current. TTL compatibility supports connection to older digital logic, while the broad supply range accommodates both low-voltage control systems and higher-voltage industrial rails.
Each channel contains an inverting input, a non-inverting input, and an output. When the non-inverting input is higher than the inverting input, the corresponding open-collector transistor turns on and pulls the output toward ground. Reversing the input relationship turns the transistor off and allows the pull-up resistor to raise the output. This behavior can be used for window detection, signal conditioning, current monitoring, and fault isolation without requiring a dedicated push-pull output driver.
Typical uses include industrial sensor interfaces, battery monitoring, overvoltage and undervoltage detection, TTL-to-open-collector conversion, and embedded control logic. The SOIC-8 package simplifies assembly on conventional surface-mount boards, while the separate comparator channels allow one side of the circuit to monitor a power rail while the other handles a control threshold. External pull-up resistors must be selected according to the required sink current, logic voltage, rise time, and bus capacitance.
The principal design consideration is that an open-collector output does not define a valid high voltage by itself. Place the pull-up resistor close to the relevant logic input, confirm that the sink current remains within the output rating, and account for bus rise time when capacitance is significant. The LM393DRE4 is best suited to commercial-temperature designs that require a low-cost, wide-supply dual comparator without rail-to-rail push-pull outputs.
This page combines the device's core electrical characteristics, package details, application guidance, drop-in alternatives, and design trade-offs in a format that helps engineers evaluate the LM393DRE4 before integrating it into a comparator or protected-interface circuit.
直接替換替代品，適用於 LM393DRE4 — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： LM393DRE4 （相同外形與佔位） — 差異在於 Comparator Type, Logic Compatibility, Output Type, Number of Channels, Differential Input Voltage Range.
LM393DG4
✅ 直接替換聯絡詢價
查看資料表 →LM393DR2G
✅ 直接替換聯絡詢價
查看資料表 →LM393DRG3
✅ 直接替換聯絡詢價
查看資料表 →LM393DRE4 最大額定值與電氣特性
| Comparator Count | 2 |
| Comparator Type | Differential, dual channel |
| Supply Voltage Range | 2 V to 36 V |
| Maximum Rated Supply Voltage | 18 V |
| Propagation Delay | 300 ns |
| Supply Current per Comparator | 0.4 mA typical |
| 輸出類型 | Open-collector |
| Input Common-Mode Range | Rail-to-rail |
| Logic Compatibility | TTL |
| Maximum Operating Temperature | 70°C |
| 腳位數 | 8 pins |
| Package Type | SOIC-8 |
| 安裝類型 | Surface mount |
LM393DRE4 soic-8 腳位配置指南
LM393DRE4（soic-8 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： LM393DRE4.
請參閱 資料表 以查看完整腳位配置。
典型應用
LM393DRE4 適用於 6 應用s: Industrial Sensor Threshold Interface, Battery Voltage Monitoring, Overvoltage and Undervoltage Protection, TTL and CMOS Logic Interface, Embedded Control and System Monitoring, Automotive and Equipment Status Detection.
Industrial Sensor Threshold Interface
The LM393DRE4 fits sensor interfaces that convert an analog or switching sensor condition into a logic-level event. Its two independent differential channels can evaluate separate thresholds, while the 300 ns response time supports prompt detection. Rail-to-rail input behavior is useful when the sensor signal approaches the available supply range. The open-collector outputs permit pulled-up industrial logic levels, although the pull-up voltage should be selected independently from the comparator supply when permitted by the device specifications. Commercial applications should remain within the 70°C temperature designation.
推薦
Battery Voltage Monitoring
The LM393DRE4 can monitor a battery-derived voltage against a reference or divided threshold and assert an open-collector alert. The wide 2 V to 36 V operating capability supports multiple system rails, while dual channels allow separate warning and shutdown thresholds. A resistive divider at each input establishes the comparison points, and the output requires a pull-up resistor for a valid high state. Because the input pins are differential, common-mode behavior and offset voltage must be considered when designing a precise protection threshold.
推薦
Overvoltage and Undervoltage Protection
The LM393DRE4 is appropriate for window detection in power-supply and load-switch systems. One channel can compare a divided rail against an upper reference, while the second detects a lower excursion. Its 300 ns response time enables rapid fault signaling, and the open-collector outputs can pull up an enable, reset, or fault line without driving a push-pull signal directly. Design the divider tolerances for the required threshold accuracy and confirm that the supply and input limits remain valid during a fault condition.
推薦
TTL and CMOS Logic Interface
The LM393DRE4 can provide open-collector interfacing between analog control logic and digital systems. Its stated TTL compatibility supports legacy digital nodes, while an external pull-up allows the output to match the receiving logic family. This arrangement is useful for wired fault signals, reset requests, and level-shifted control indications. The 0.4 mA typical supply drain per comparator helps limit overhead in continuously powered systems. Designers must verify output sink-current capability and select the pull-up so that the resulting rise time satisfies the connected logic device.
推薦
Embedded Control and System Monitoring
The LM393DRE4 can support embedded controllers that need inexpensive discrete threshold decisions outside the microcontroller analog inputs. One channel may monitor a power-good signal, temperature switch, or supervisor output, while the other performs a second comparison. The SOIC-8 format permits straightforward assembly alongside a controller in surface-mount assemblies. Its dual-channel architecture reduces package count, and the open-collector output can be shared where the pull-up is designed for the worst-case sink current. The 70°C commercial grade should be checked against the final ambient-temperature requirement.
推薦
Automotive and Equipment Status Detection
The LM393DRE4 can implement equipment-status detection in automotive and industrial subsystems where a two-wire or open-collector status output is preferred. The two channels provide independent fault comparisons, and the 300 ns response supports fast transition signaling. The SOIC-8 package is compatible with common surface-mount assembly methods. However, the published 70°C designation does not cover the full automotive temperature range, so this ordering code should be used only where environmental requirements are confirmed. Pull-up resistors and fault thresholds require validation across normal and fault operating states.
推薦
推薦產品摘要
工程參考資料，適用於 LM393DRE4 — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | LM393DG4 | LM393DR2G | LM393DRG3 | LM393DRG4 | LM393DT |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | STMicroelectronics |
| Package | SOIC-8 | SOIC-8 - same footprint | SOIC-8 - same footprint | SOIC-8 - same footprint | SOIC-8 - same footprint | SOIC-8 - same footprint |
| Comparator Count | 2 | 2 | 2 | 2 | 2 | 2 |
| Output Type | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector |
主要差異化特點
- Two independent comparator channels in one package (對比LM393DT)
- Broad supply operating range (對比LM393DG4)
- Open-collector output supports wired logic (對比LM393DRG4)
設計說明
Do not treat an open-collector output as a push-pull logic output. The output can sink current but cannot actively source a high level, so every comparator output needs a pull-up resistor. Select the resistor against the maximum sink current, required rise time, power dissipation, and capacitance of the connected bus. A common design error is to leave the output transistor state active during reset, which can prevent the pull-up from establishing a valid high voltage.
Place the pull-up resistor close to the comparator output or receiving logic input, and keep the route short enough to limit capacitance and susceptibility to injected noise. Connect the supply and ground pins with low-impedance traces and place their decoupling capacitor near the device. Sensitive threshold inputs should avoid running parallel to switching-node or high-current return paths, because input offset and noise can shift the point at which the output changes state.
The LM393DRE4 is specified for operation from 2 V to 36 V, but the 18 V maximum rated supply condition for this ordering variant must be respected. Check the exact manufacturer ordering limits before connecting the device to a 24 V industrial rail. Do not allow transient input or supply voltages to exceed the absolute-maximum rating, and confirm that the external pull-up rail cannot exceed the permitted output-pin voltage.
Design threshold dividers and hysteresis feedback for the actual input offset, bias current, and temperature range rather than assuming perfect matching between channels. Keep the reference node within the valid common-mode range and account for resistor tolerance. For window detection, add controlled hysteresis if the monitored signal can cross the threshold slowly, otherwise noise near the comparison point can cause repeated output transitions.
合規資訊
The LM393DRE4 is a commercial-grade 70°C dual comparator. Specific RoHS, REACH, lead-free, halogen-free, and conflict-minerals declarations require confirmation from the manufacturer product documentation.
