LM339PT - 4-Channel Open-Collector Comparator | STMicroelectronics
MPN： LM339PT ✓ 啟用中LM339PT 概覽
A voltage comparator is an analog integrated circuit that compares two input voltages and changes its output state according to their relationship. The LM339 belongs to the comparator hierarchy within analog and mixed-signal semiconductors. Its four independent channels can perform threshold detection, overvoltage monitoring, window comparison, zero-crossing detection, and general-purpose signal conditioning. Unlike a digital logic gate, the comparator evaluates continuously varying analog voltages at its inputs.
The main feature of the LM339PT is its combination of four independent open-collector comparators in one compact TSSOP-14 package. Its low-power design is suitable for battery-powered equipment, while the broad supply-voltage range supports industrial control and instrumentation systems. The open-collector architecture requires an external pull-up resistor and can interface with CMOS or TTL logic. The verified distributor description also reports a propagation delay of 1.3 µs, making the device suitable for moderate-speed threshold and protection functions rather than ultra-high-speed applications.
Each comparator channel has two input pins, an output, and access to the device ground and supply pins. The outputs are open-collector rather than push-pull, so an output can sink current while remaining high-impedance when inactive. Pull-up resistors are therefore required on every used output. Connecting outputs together requires compatible pull-up arrangements and careful review of the maximum sink-current and voltage limits. The device does not provide a latch function, so applications requiring state retention normally add external feedback or latch circuitry.
Typical uses include DC overvoltage detection, power-supply sequencing, sensor threshold switching, battery monitoring, industrial control interfaces, and logic-level conversion. Split-supply operation allows the comparator to evaluate signals around ground, while single-supply operation is useful when all measured signals remain above the common-mode limits. Because the outputs are open collector, the device can also connect to buses such as SMBus or I2C where wired-AND behavior is required, provided the electrical and timing requirements of the specific bus are satisfied.
Designers should account for input common-mode range, output pull-up resistance, supply decoupling, and the behavior of the open-collector output at temperature extremes. Place the device close to the protected signal and provide a stable ground reference. Avoid relying on an output to source current, and select a pull-up voltage compatible with both the comparator output ratings and the driven logic family. The TSSOP-14 package supports compact PCB layouts, but pin-1 orientation must be checked carefully because closely spaced leads can complicate hand rework.
This product page consolidates verified distributor availability and pricing, package information, same-package cross-references, and practical design guidance. It also distinguishes drop-in replacements from devices that differ in package or temperature grade, helping engineers make a replacement decision without assuming that every similarly named LM339 variant is electrically and mechanically interchangeable.
直接替換替代品，適用於 LM339PT — 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： LM339PT （相同外形與佔位） — 差異在於 Comparator Type, Number of Channels, Output Type, Package, Propagation Delay.
LM239PT
✅ 直接替換📋 參考替代品（不在目錄中）
LM339PT 最大額定值與電氣特性
| Comparator Type | Low-power quad voltage comparator |
| Number of Channels | 4 independent channels |
| Supply Voltage Range | 1 V to 16 V |
| Input Offset Voltage | 2 mV maximum for LM339A-family specification |
| Propagation Delay | 1.3 µs |
| 輸出類型 | Open collector |
| Logic Compatibility | CMOS, DTL, ECL, MOS, open-collector, and TTL |
| Supply Configuration | Single supply or split supply |
| 封裝 | TSSOP-14 |
| 腳位數 | 14 pins |
| 安裝類型 | Surface mount |
LM339PT 腳位配置
| 腳位 1 | 1OUT — Comparator 1 open-collector output |
| 腳位 2 | 1IN- — Comparator 1 inverting input |
| 腳位 3 | 1IN+ — Comparator 1 non-inverting input |
| 腳位 4 | GND — Ground |
| 腳位 5 | 2IN+ — Comparator 2 non-inverting input |
| 腳位 6 | 2IN- — Comparator 2 inverting input |
| 腳位 7 | 2OUT — Comparator 2 open-collector output |
| 腳位 8 | 3OUT — Comparator 3 open-collector output |
| 腳位 9 | 3IN- — Comparator 3 inverting input |
| 腳位 10 | 3IN+ — Comparator 3 non-inverting input |
| 腳位 11 | VCC — Positive supply |
| 腳位 12 | 4IN+ — Comparator 4 non-inverting input |
| 腳位 13 | 4IN- — Comparator 4 inverting input |
| 腳位 14 | 4OUT — Comparator 4 open-collector output |
典型應用
LM339PT 適用於 6 應用s: Power-Supply Overvoltage Detection, Battery Threshold Monitoring, Industrial Sensor Interfacing, Logic-Level Detection, Window and Limit Detection, Open-Collector Fault Summing.
Power-Supply Overvoltage Detection
The LM339PT fits power-supply protection because its four independent channels can compare a divided feedback voltage with a reference and assert an open-collector fault signal when the monitored rail exceeds a threshold. The verified 1 V to 16 V operating range supports low-voltage systems, while the 1.3 µs propagation delay is suitable for normal supply supervision rather than nanosecond-scale fault detection. Each used output needs a pull-up resistor, allowing the fault indication to remain compatible with CMOS or TTL system logic. A practical implementation places the divider close to the regulated rail, routes the comparator input away from switching-node currents, and connects the fault output to a supervisor, reset controller, or disable input. The wide supply tolerance supports single-rail operation, although split-supply operation can provide better ground-centered sensing when required.
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Battery Threshold Monitoring
The LM339PT can monitor a battery or energy-storage cell against multiple threshold points using its four independent comparator channels. Its low-power quad-comparator design and verified 1 V minimum supply are appropriate for compact battery-powered equipment, while the open-collector outputs can drive an external pull-up or a low-power status indicator. The 1.3 µs delay is more than adequate for slow battery-voltage changes and reduces the likelihood of false switching from normal transient variation. For accurate cell monitoring, use a resistor divider with defined tolerances and ensure the battery voltage remains inside the comparator input common-mode range. Exact quiescent current was not present in the supplied data, so engineers should obtain that value before calculating standby-current budgets or designing around the 1 V supply limit.
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Industrial Sensor Interfacing
The LM339PT is useful for converting analog sensor outputs into digital threshold events in industrial control systems. Its four channels can monitor temperature, pressure, level, or position signals against independently generated references, while the open-collector output provides flexible interfacing to PLC inputs or other digital circuits. The 1 V to 16 V supply range accommodates common industrial signal levels, and the 1.3 µs propagation delay is adequate for relatively slow process variables. The main design constraint is common-mode range: the selected sensor output must remain inside the comparator's permitted input window under every operating condition. Place the sensing divider or interface close to the comparator, use a stable reference, and route high-current switching paths away from the input nodes to minimize threshold errors.
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Logic-Level Detection
The LM339PT can detect whether a logic signal is above or below a defined threshold, making it suitable for legacy CMOS and TTL interfacing. The verified compatibility list includes CMOS, DTL, ECL, MOS, open-collector, and TTL logic, while the 1.3 µs propagation delay is adequate for ordinary control and handshake signals. Use the device when analog threshold behavior is needed rather than simply reproducing an existing logic function. Each channel compares a signal against a reference and produces an open-collector state that requires a pull-up. Choose the pull-up voltage so the high level satisfies the receiving logic family, and confirm that the input voltage remains within the comparator's common-mode limits. This arrangement can also provide fault signaling when a bus becomes stuck high or falls outside the expected logic threshold.
推薦
Window and Limit Detection
Two LM339PT channels can form a voltage window detector by comparing a monitored signal against upper and lower references, while another channel can provide an independent fault or enable output. The quad architecture consolidates several protection functions into one 14-pin TSSOP device and reduces duplicated external circuitry. Its open-collector outputs can be pulled up independently or combined where wired-AND behavior is appropriate. Window accuracy depends on reference stability, resistor matching, comparator offset, and the device's input offset specification, reported as low as 2 mV maximum for the A-grade family. For a production design, verify the exact offset grade, common-mode range, and propagation-delay limits in the ordered manufacturer's datasheet. The 1.3 µs verified delay is suitable for slow analog envelopes but not for high-speed timing windows.
推薦
Open-Collector Fault Summing
The LM339PT is well suited to collecting multiple fault conditions because each channel provides an open-collector output that can be tied to a common pull-up. When any channel detects an abnormal condition and sinks the common line, the resulting signal identifies a fault without requiring a wired-AND gate. This can simplify system monitoring across power rails, communications interfaces, or safety-related analog thresholds. The shared line must use only outputs whose sink-current and voltage limits permit parallel operation, and it must remain within every connected channel's absolute maximum rating. Pull-up resistance controls the fault-signal rise time and current consumption. The comparator's 1.3 µs propagation delay helps combine indications without substantial timing uncertainty, although fault-path delay must be included in the overall system safety analysis.
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推薦產品摘要
工程參考資料，適用於 LM339PT — 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 | LM239PT | LM339PT | LM339PT |
|---|---|---|---|---|
| Package | TSSOP-14 | TSSOP-14 | TSSOP-14 | TSSOP-14 |
| Brand | STMicroelectronics | STMicroelectronics | ROHM Semiconductor | Texas Instruments |
| Comparator Channels | 4 independent channels | 4 channels | 4 channels | 4 channels |
| Output Type | Open collector | Open collector | Open collector | Open collector |
| Number of Pins | 14 pins | 14 pins | 14 pins | 14 pins |
主要差異化特點
- Four independent comparator channels in one compact package (對比LM239PT)
- Direct same-package second source using the identical MPN (對比ROHM Semiconductor LM339PT)
- Verified operating range and moderate propagation delay (對比Texas Instruments LM339PT)
設計說明
Every used LM339PT open-collector output requires an external pull-up resistor because the output transistor can sink current but cannot source the high-state current. Select the resistor to balance signal rise time, power consumption, and the output's sink-current rating. Do not allow the pull-up voltage to exceed the output-pin absolute maximum rating. The verified supply range is 1 V to 16 V, but the selected pull-up and the logic load must remain compatible with the device's output limits.
Route comparator inputs away from switching nodes, inductors, and high-current return paths because small threshold errors can create false switching. Keep the reference-divider ground connection close to pin 4 and use a short, low-impedance ground path. Decouple the supply near the device with the capacitance and voltage rating specified by the manufacturer. Although a 1.3 µs propagation delay is suitable for ordinary threshold detection, PCB-induced noise can still shift the effective input threshold and should be evaluated in system testing.
Do not treat same-package LM339-family devices as automatically equivalent. Confirm supply range, input common-mode limits, offset grade, propagation delay, output sink current, absolute maximum ratings, and temperature grade in the datasheet of the exact manufacturer. Also verify that the PCB accounts for TSSOP lead pitch and pin-1 orientation. An open-collector output tied to another channel requires a common pull-up and must remain within the sink-current and voltage ratings of every connected output.
合規資訊
The supplied verified data does not state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. The device is a general-purpose comparator rather than an automotive-qualified alternative.
