LT319AN - Dual 80ns Comparator, 14-PDIP | Analog Devices
MPN： LT319AN ✓ 啟用中LT319AN 概覽
A comparator is an integrated circuit that compares two input voltages and produces a logic-level output indicating which input is higher. As a dual comparator, the LT319AN contains two independent comparison channels in one package. This dual-channel structure places the device in the comparator hierarchy: comparator > analog comparator > linear integrated circuit > semiconductor. It is useful when a system needs fast threshold detection, signal conditioning, or differential logic conversion.
The LT319A family is described by Analog Devices as an improved version of the LM119 dual comparator. Its key advantages include lower input offset voltage and offset current, higher voltage gain, guaranteed common-mode rejection, and input protection diodes. The maximum 0.5 mV offset specification reduces ambiguity near the switching threshold, while the 80 ns response time supports high-speed decision-making. The 25 mA output drive capability allows the outputs to interface with suitable TTL-compatible circuitry.
Operation from a single 5 V supply simplifies the power architecture in TTL and mixed-signal systems. The 14-pin PDIP package also supports conventional through-hole assembly and prototyping. Because output behavior and input common-mode limits depend on the supply configuration, designers should consult the manufacturer datasheet before using the device outside its stated operating conditions. The separate ground arrangement discussed for the LT319A family can also assist system-ground isolation where applicable.
Typical uses include high-speed threshold detection, pulse-width and timing measurements, zero-cross detection, signal conditioning, and two-channel sensing. One comparator channel can compare a sensor signal with a reference while the other performs an independent threshold or differential decision. The fast 80 ns response helps minimize propagation delay in timing-sensitive systems, and the 0.5 mV maximum input offset improves threshold repeatability.
Layout should keep input and output paths short, provide a stable return path, and avoid routing sensitive input traces beside high-current switching nodes. Input protection diodes require attention when signals can exceed the supply rails. Designers should also account for output rise and fall time, supply bypassing, and input common-mode range when interpreting the 80 ns response specification.
This page combines the verified manufacturer and distributor information with practical application guidance, sourcing details, comparison data, and design notes. It distinguishes explicitly verified LT319AN characteristics from parameters that still require confirmation from the official LT319A datasheet.
直接替換替代品，適用於 LT319AN — 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： LT319AN （相同外形與佔位） — 差異在於 Comparator Type, Mounting Type, Number of Channels, Package.
LT319AN#PBF
✅ 直接替換聯絡詢價
查看資料表 →LT119AN
✅ 直接替換📋 參考替代品（不在目錄中）
LT1016AN
✅ 直接替換📋 參考替代品（不在目錄中）
MAX942N
✅ 直接替換📋 參考替代品（不在目錄中）
MAX912N
✅ 直接替換📋 參考替代品（不在目錄中）
LT319AN 最大額定值與電氣特性
| Comparator Type | Dual general-purpose comparator |
| Number of Channels | 2 channels |
| Maximum Input Offset Voltage | 0.5 mV |
| Response Time | 80 ns |
| Output Drive Capability | 25 mA |
| Single-Supply Operation | 5 V |
| 輸出類型 | Open-collector, open-emitter, TTL-compatible |
| Input Protection | Input protection diodes |
| 封裝 | 14-pin PDIP |
| 安裝類型 | Through-hole |
LT319AN 14-pin pdip 腳位配置指南
LT319AN（14-pin pdip 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： LT319AN.
請參閱 資料表 以查看完整腳位配置。
典型應用
LT319AN 適用於 6 應用s: High-Speed Threshold Detection, Pulse-Width and Timing Measurement, Zero-Cross Detection, TTL Logic Signal Conditioning, Industrial Sensor Interfacing, Power-Sequencing and Rail Monitoring.
High-Speed Threshold Detection
The LT319AN fits threshold-detection stages that require fast propagation and repeatable comparison near the reference voltage. Its verified 80 ns response time limits comparator delay, while the guaranteed maximum 0.5 mV input offset helps define a narrow decision band around the threshold. Two independent channels can monitor two signals or provide redundant decisions on the same board. The open-collector/open-emitter outputs need the correct pull-up arrangement for TTL-compatible interfacing, and input excursions beyond the supply rails require external protection because the device includes input protection diodes.
推薦
Pulse-Width and Timing Measurement
The LT319AN can compare a timing signal against a generated reference to determine whether a pulse or interval exceeds a defined threshold. The 80 ns response time is valuable when timing edges must be detected quickly, and the 0.5 mV maximum offset helps maintain a stable comparison boundary when the relevant signal is a voltage rather than a logic edge. The dual architecture allows one channel to monitor the event while the second handles a complementary limit or another timing phase. Board design should minimize comparator input capacitance and return lead inductance because these effects can add delay beyond the specified response time.
推薦
Zero-Cross Detection
The LT319AN is suitable for detecting the transition of an analog waveform through zero or another defined reference. Its fast 80 ns response reduces the delay between the input crossing and the resulting logic transition, while the maximum 0.5 mV offset defines the accuracy of the comparison region. The two channels can monitor positive and negative crossings, or one channel can provide a second decision or alarm. Designers should preserve a low-noise reference path, avoid placing the input beside switching-current traces, and account for input protection behavior if the source can exceed the comparator supply limits.
推薦
TTL Logic Signal Conditioning
The LT319AN can translate analog thresholds into TTL-compatible logic because the verified distributor data identifies open-collector, open-emitter, TTL operation and the family data specifies 25 mA output drive capability. Its 0.5 mV maximum input offset is useful when converting a carefully controlled analog level into a dependable binary decision, and its 80 ns response supports higher-speed logic interfaces. The output topology requires the correct pull-up resistor and return path. Engineers should also verify the allowed output voltage, sink current, input common-mode range, and supply limits in the official datasheet.
推薦
Industrial Sensor Interfacing
The LT319AN can compare a conditioned industrial sensor signal with a reference to produce a discrete limit, alarm, or control event. Its dual-channel architecture allows two thresholds to be evaluated without using two packages, and the 80 ns response is generally sufficient for rapid discrete decisions. The 0.5 mV maximum input offset is meaningful only if the upstream sensor and reference paths do not introduce more error, so input conditioning and grounding remain important. For industrial use, verify the LT319AN operating-temperature rating, supply limits, and applicable qualification because those values were not included in the supplied snippets.
推薦
Power-Sequencing and Rail Monitoring
The LT319AN can evaluate a divided power rail against a reference and report whether the rail is above or below a selected threshold. The two channels permit monitoring of two rails or supplying complementary conditions, while the 80 ns response supports prompt transitions during startup or fault events. A controlled reference source and low-impedance divider are necessary because resistor tolerance and input offset can affect the actual trip point. Output pull-up selection must preserve valid TTL-compatible levels, and any monitored signal exceeding the comparator supply range requires external attenuation or clamping.
推薦
推薦產品摘要
工程參考資料，適用於 LT319AN — 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 | LT319AN#PBF | LT119AN | LT1016AN | MAX942N | MAX912N |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 14-PDIP | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same |
主要差異化特點
- Fast verified response with tight offset (對比MAX912N)
- Dual channels in one 14-pin PDIP (對比LT1016AN)
- Improved LT319A family positioning versus LM119 (對比LM119)
- Explicit TTL-compatible open output interface (對比MAX942N)
設計說明
Keep the two comparison inputs short and symmetric, and provide a nearby ground return so input switching cannot add meaningful error to the decision. The guaranteed maximum input offset is only 0.5 mV, so resistor noise, reference drift, leakage, and ground bounce can dominate the effective accuracy. Avoid routing either input beneath or parallel to a high-current switching path. Where a slow reference is used, confirm that its settling behavior meets the system timing requirement rather than relying only on the comparator's 80 ns response specification.
The LT319AN is verified for operation from a single 5 V supply, and the broader electrical limits must be taken from the official LT119A/LT319A datasheet. Place the required supply-decoupling capacitor close to the device's supply and ground pins, with a short and sufficiently wide return path. Because the output is open-collector/open-emitter, select the pull-up voltage and resistor from the output-current, logic-level, and system-noise requirements. Changing the pull-up voltage can affect rise time and therefore total decision delay even when the 80 ns intrinsic response is unchanged.
Do not assume that 25 mA output drive is permissible under every pull-up or supply condition. Check sink current, output voltage, output-current limits, and input protection behavior against the manufacturer data. An input signal that can rise above or fall below the allowed common-mode range may forward-bias the input protection diodes and disturb the reference or source. Add series resistance or clamping where needed, and verify the numbered 14-pin PDIP pinout directly from the official PDF before laying out the PCB.
Place the part close to the source and destination of each decision to minimize trace delay and susceptibility to interference. Keep output pull-up resistors close enough to the comparator to form a compact, low-inductance output loop, while maintaining separation between the pull-up return and sensitive input reference. Use a ground plane or uninterrupted return path rather than routing ground through the output current path. The PDIP package supports easy prototyping and inspection, but through-hole lead inductance can add delay compared with a suitable surface-mount implementation.
合規資訊
The supplied verified pages establish the LT319A family, a 14-PDIP package, and an LT319AN#PBF ordering option, but they do not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status for the exact LT319AN ordering code. The #PBF suffix is recorded in the verified listings but is not treated as proof of compliance without the corresponding manufacturer declaration.