LM339AM - Quad Open-Collector Comparator | Texas Instruments
Артикул: LM339AM ✓ АктивенLM339AM Обзор
A comparator is an analog integrated circuit that compares two input voltages and changes its output state when the non-inverting input rises above the inverting input. The LM339 belongs to the voltage-comparator hierarchy, which falls within analog and mixed-signal ICs and ultimately the broader semiconductor category. Its four channels can operate independently or be configured as two window or hysteretic comparison functions.
Key features include four open-collector outputs, low quiescent current, low input offset voltage, and wide input-voltage capability. The open-collector architecture requires an external pull-up resistor and permits several open-collector outputs to share a wired bus when their device-current limits and logic levels are compatible. The 14-pin SOIC package supports conventional surface-mount assembly while providing separate inputs, outputs, and two ground pins.
Internally, each channel uses a differential input stage followed by an open-collector output stage. The inputs can be driven near ground, making the device suitable for low-level sensing where the signal of interest lies close to the lower supply rail. Because the outputs are open collectors rather than push-pull outputs, output rise time depends on the pull-up resistor, bus capacitance, and leakage current rather than only on the comparator itself.
Typical applications include battery threshold detection, sensor-level conditioning, window comparators, industrial control interfaces, and low-level memory or control monitoring. Industrial systems benefit from the wide common-mode capability, while consumer and communication equipment can use the open-collector outputs directly with pull-up resistors. Four independent channels also reduce the component count in multi-level or multi-signal designs.
Designers should verify supply voltage, input common-mode limits, output pull-up values, and propagation delay under the intended load. The open-collector output must never be left without a pull-up path, and unused comparator inputs should be tied to a defined potential to prevent unintended switching. PCB placement should keep pull-up resistors close to the output pins and minimize routing through noisy analog or switching nodes.
This page combines the supplied manufacturer and distributor information with practical pin, replacement, application, and design guidance. It also distinguishes verified ordering information from details that must still be confirmed against the manufacturer datasheet before production release.
Аналоги без доработки для LM339AM — тот же корпус, pin-to-pin совместимость. Компоненты в других корпусах, требующие переработки PCB, исключены.
Варианты в этой серии
Модели той же серии, совместимые без доработки с LM339AM (тот же форм-фактор и посадочное место) — отличается по Logic Compatibility, Output Type, Package.
LM339AM/NOPB
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
LM339D
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Открыть даташит →LM339MX
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Открыть даташит →LM339AM
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Открыть даташит →LM339AM
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Открыть даташит →LM339AM Максимальные параметры и электрические характеристики
| Comparator Type | Low-power, low-offset differential voltage comparator |
| Number of Comparison Channels | 4 independent channels |
| Тип выхода | Open collector |
| Logic Compatibility | Compatible with DTL, MOS, TTL, and CMOS |
| Differential Input Voltage Range | Up to ±38 V |
| Common-Mode Input Voltage Range | Includes ground |
| Корпус | 14-pin SOIC, 3.90 mm wide body |
| Тип монтажа | Surface mount |
| Диапазон рабочих температур | 0°C to 70°C |
| Number of Power Pins | 1 positive supply pin and 2 ground pins |
| Output Interface | Open-collector wired-bus interface with external pull-up |
| Typical Applications | Level detection, low-level sensing, memory, consumer, automotive, and industrial electronics |
Конфигурация выводов LM339AM
| Контакт 1 | OUT 1 — Comparator 1 open-collector output |
| Контакт 2 | IN- 1 — Comparator 1 inverting input |
| Контакт 3 | IN+ 1 — Comparator 1 non-inverting input |
| Контакт 4 | GND — Ground connection |
| Контакт 5 | IN+ 2 — Comparator 2 non-inverting input |
| Контакт 6 | IN- 2 — Comparator 2 inverting input |
| Контакт 7 | OUT 2 — Comparator 2 open-collector output |
| Контакт 8 | OUT 3 — Comparator 3 open-collector output |
| Контакт 9 | IN- 3 — Comparator 3 inverting input |
| Контакт 10 | IN+ 3 — Comparator 3 non-inverting input |
| Контакт 11 | GND — Ground connection |
| Контакт 12 | IN+ 4 — Comparator 4 non-inverting input |
| Контакт 13 | IN- 4 — Comparator 4 inverting input |
| Контакт 14 | OUT 4 — Comparator 4 open-collector output |
Типичное применение
LM339AM подходит для 6 применениеs: Battery Voltage Threshold Detection, Industrial Sensor-Level Conditioning, Power-Supply Overvoltage and Undervoltage Protection, Automotive and Consumer Low-Level Sensing, Memory and Logic Interface Control, Communications Equipment Threshold Detection.
Battery Voltage Threshold Detection
The LM339AM fits battery-threshold monitoring because each of its four channels compares two input voltages and includes ground in the common-mode input range. Two channels can form a battery window detector, while the other two can monitor charger state or individual cell thresholds. The verified differential input capability extends to ±38 V, allowing suitably rated input networks to sense higher-voltage systems without placing those voltages directly on the IC pins. Each open-collector output can pull a system status line low and use an external pull-up for a defined high state. Designers should still verify the actual LM339AM supply range, input bias current, offset voltage, and propagation delay before fixing resistor values. Resistor tolerances and reference stability will determine the practical threshold accuracy.
Рекомендуется
Industrial Sensor-Level Conditioning
The LM339AM is appropriate for industrial sensor interfaces whose signals operate near ground, because the verified common-mode input range includes ground. Four independent comparison channels can evaluate pressure, temperature, position, or liquid-level sensor outputs without using four separate packages. The LM339AM open-collector outputs can directly pull up logic, relay-driver inputs, or industrial interface lines low, while the external pull-up resistor sets the high-level voltage. This architecture is useful when the downstream system expects an active-low fault signal. Industrial qualification requirements remain application-specific, so designers should confirm operating-temperature limits, input noise, offset behavior, and electrical isolation strategy for each deployment rather than assuming that a general-purpose comparator provides reinforced industrial protection.
Рекомендуется
Power-Supply Overvoltage and Undervoltage Protection
The LM339AM can supervise multiple power rails by comparing divided rail voltages against references and driving open-collector fault outputs. Its four channels support two complete overvoltage-or-undervoltage window functions, or four individual rail alarms. The verified ±38 V differential input capability provides useful design margin when the monitored rail is scaled by high-value resistors, although the actual common-mode and supply limits must be checked for every operating condition. Open-collector outputs allow multiple devices to share a fault bus, but the designer must confirm that the aggregate sink current remains below the output-current rating and that the pull-up voltage is compatible with every attached logic device. This makes the LM339AM suitable for simple, cost-conscious protection without a complex digital monitor.
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Automotive and Consumer Low-Level Sensing
The LM339AM can be used in automotive and consumer sensing circuits for level detection, low-level sensing, and memory-related control, as stated in the verified device descriptions. Four channels provide useful integration for systems monitoring several discrete signals, while the open-collector output can operate at the voltage selected by an external pull-up. Common-mode operation that includes ground is useful when detecting the presence of a battery-backed or low-voltage signal. However, the LM339AM ordering code supplied by Mouser is specified for 0°C to 70°C operation, so it should not be assumed to satisfy automotive temperature requirements. A qualified automotive variant or an appropriately rated alternative must be selected when the enclosure, vehicle environment, or functional-safety process demands it.
Рекомендуется
Memory and Logic Interface Control
The LM339AM fits memory and logic interface control because the verified product descriptions identify memory and level detection among its intended uses. A pair of channels can compare a data or status signal against a reference and generate an open-collector control indication for memory-enable, reset, or write-protect logic. The common-mode range including ground supports low-level signal detection, while the open-collector output permits wired-AND fault signaling. Because output transition timing depends partly on the external pull-up and bus capacitance, a slow pull-up can create excessive rise time, whereas a low pull-up can increase sink-current demand. The implementation should therefore be validated with realistic bus loading, and unused channels should be configured with defined input levels to prevent false fault events.
Рекомендуется
Communications Equipment Threshold Detection
The LM339AM is suitable for communications equipment that needs simple, independent threshold decisions at control, status, or alarm inputs. Its four channels can monitor receive-level, supply, reset, or timing signals, and the open-collector outputs can be pulled up to the logic rail used by the surrounding equipment. The verified logical compatibility with TTL, MOS, DTL, and CMOS makes the interface concept broadly reusable, although voltage-level and timing details must be verified for the selected logic family. In systems with multiple fault outputs, the shared open-collector bus can reduce logic components, but designers must account for the maximum number of simultaneously asserted outputs and ensure that the resulting sink current remains safe. A defined pull-up and a deliberate fault-input priority should be included in the schematic.
Рекомендуется
Сводка рекомендуемых товаров
Справочные инженерные данные для LM339AM — сравнение, рекомендации по проектированию и информация о соответствии.
Руководство по выбору
Сравнение с аналогами
| Параметр | Этот товар | LM339AM/NOPB | LM339D | LM339MX | LM339AM (onsemi) | LM339AM (Fairchild Semiconductor) |
|---|---|---|---|---|---|---|
| Package | 14-pin SOIC | 14-pin SOIC | 14-pin SOIC | 14-pin SOIC | 14-pin SOP | 14-pin SOP |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | onsemi | Fairchild Semiconductor |
| Comparator Configuration | Quad differential comparator | Quad differential comparator | Quad differential comparator | Quad differential comparator | Quad differential comparator | Quad differential comparator |
| Primary Application | Level detection, low-level sensing, memory, consumer, automotive, and industrial electronics | General-purpose open-collector comparison | LM339-family comparator | LM339-family comparator | Standard general-purpose comparison | General-purpose comparison |
Ключевые отличия
- Four independent channels in one package (против TLV1504ID)
- Open-collector wired-bus output (против LM339AM/NOPB)
- Ground-inclusive common-mode operation (против LM339D)
- Broad logic-interface compatibility (против LM339AM (onsemi))
Заметки по проектированию
Every open-collector output requires a pull-up path to a valid logic supply. Without one, the output state is undefined even though the transistor can correctly pull the node low. Use separate pull-ups when outputs drive unrelated loads, or a shared pull-up only when the bus topology, sink-current total, and fault polarity have been verified. Avoid tying the output to a supply rail through a pull-up unless the downstream circuit is designed for an active-high signal.
The supplied source identifies a differential input capability of up to ±38 V, but that rating must not be confused with permission to apply 38 V directly to every input pin in every operating mode. Confirm the exact LM339AM supply-voltage and common-mode limits against the manufacturer datasheet, especially when sensing high-voltage industrial or automotive rails. Use appropriately rated resistor dividers and protection components to keep both the common-mode voltage and differential voltage within their respective limits.
Place the pull-up resistor close to the LM339AM output pin to limit the duration for which the open-collector node floats during switching. Route comparator inputs away from switching nodes, relay coils, high-current rails, and inductors. Where a comparator controls a long digital trace or cable, consider a series resistor or stronger buffer at the receiver. The two ground pins should be connected to a low-impedance ground plane, while analog reference components should remain physically separated from noisy switching-current paths.
Do not leave unused comparator inputs floating. Tie each unused non-inverting input to ground and its corresponding inverting input to the same defined reference, subject to the input-voltage limits, so that the unused channel cannot switch randomly. Also verify that the output pull-up voltage and the LM339AM supply arrangement remain valid during power-down. Slow output rise caused by an excessively large pull-up may violate downstream setup timing even when the comparator itself is operating correctly.
Информация о соответствии
The supplied search results do not explicitly state the required LM339AM RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. No compliance claim has been inferred from the distributor category labels.
