LT1711CMS8#PBF - 4.5ns Rail-to-Rail Comparator | Analog Devices
Teilenummer: LT1711CMS8#PBF ✓ Aktiv| Menge | Stückpreis | Gesamt |
|---|---|---|
| 1 | $7.86 | $7,86 |
| 10 | $6.85 | $68,50 |
| 100 | $5.42 | $542,00 |
| 500 | $4.65 | $2.325,00 |
| 1.000 | $4.1 | $4.100,00 |
LT1711CMS8#PBF Übersicht
A high-speed comparator is an analog building block that compares two input voltages and switches its output to a digital logic level as soon as the difference crosses zero. Within the broader component taxonomy, the LT1711 sits at the intersection of linear analog (high-speed input stage with rail-to-rail common-mode) and digital logic (latched complementary outputs). Its place in the signal chain is right at the boundary between the analog domain and the digital domain, where decisions must be made quickly and unambiguously - for example between a sensor front-end and an FPGA capture register.
Three specifications define the part's character: a 4.5 ns propagation delay at 20 mV overdrive, rail-to-rail input common-mode range that accepts signals at both supply rails, and a built-in latch pin that allows the output state to be held transparent or frozen on command. The complementary outputs reduce external inversion logic, and TTL/CMOS compatibility lets the part drive either 3.3 V or 5 V logic without level shifters. The latch enables pipelined architectures where a high-to-low transition must be frozen while downstream logic processes a previous event.
Internally, the LT1711 uses a high-speed differential input pair followed by a positive-feedback latch stage and complementary CMOS output drivers. The 4.5 ns figure is achieved at 20 mV overdrive; at 5 mV overdrive the delay increases modestly because the input stage must slew further through its linear region. The MSOP-8 package with exposed pad (when present on the same die family) keeps the thermal loop short and allows tight PCB layout for high-speed analog.
Typical applications include high-speed instrumentation triggers, time-of-flight and LIDAR threshold detectors, line receivers and signal restoration in noisy backplane links, motor control current-sense zero-cross detection, and clock/data recovery decision circuits. The wide supply range makes it useful in both 3.3 V and 5 V systems. When designing with this part, place decoupling capacitors as close as possible to V+ and V- and keep input trace lengths short; the latch pin must be held low during the active compare window and pulsed high only when freezing the output is required.
Drop-in-Alternativen für LT1711CMS8#PBF – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Varianten dieser Serie
Modelle derselben Serie, die drop-in-kompatibel sind mit LT1711CMS8#PBF (gleiche Bauform und Footprint) – abweichend in Comparator Type, Input Common-Mode Range, MSL Level, Output Latch, Output Type.
Schnellvergleichstool – Wählen Sie Alternativbauteile für den Direktvergleich:
LT1711IMS8
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT1711CMS8
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT1716CMS8#PBF
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT1715CMS8#PBF
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT1711CMS8#PBF Grenzwerte & elektrische Eigenschaften
| Comparator Type | High Speed, Single |
| Number of Comparators | 1 |
| Propagation Delay (20 mV overdrive) | 4.5 ns |
| Input Common-Mode Range | Rail-to-Rail |
| Ausgangstyp | CMOS, TTL-compatible complementary |
| Output Latch | Yes |
| Supply Voltage (Single) | 2.4 V to 12 V |
| Supply Voltage (Dual) | ±2.4 V to ±6 V |
| Quiescent Supply Current | 17 mA typical |
| Gehäuse | 8-pin MSOP |
| Montageart | Surface Mount |
| Betriebstemperatur | -40 °C to +85 °C (C grade) |
| Lead Free / RoHS | Yes (PBF suffix) |
| MSL-Level | 1 |
| Output Stage | Complementary rail-to-rail |
LT1711CMS8#PBF Pin-Konfiguration
| Pin 1 | OUTA — Non-inverting complementary output |
| Pin 2 | IN+ — Non-inverting input |
| Pin 3 | IN- — Inverting input |
| Pin 4 | V- — Negative supply (or GND for single-supply) |
| Pin 5 | LE — Latch enable (active high) |
| Pin 6 | V+ — Positive supply |
| Pin 7 | OUTB — Inverting complementary output |
| Pin 8 | GND — Ground reference (or tied to V- for single-supply) |
Typische Anwendungen
LT1711CMS8#PBF ist geeignet für 6 Anwendungs: Time-of-Flight and LIDAR Threshold Detection, High-Speed Instrumentation Trigger, Line Receiver and Signal Restoration, Motor Control Current-Sense Zero-Cross Detection, Clock and Data Recovery Decision Circuit, Battery Voltage and Threshold Monitoring.
Time-of-Flight and LIDAR Threshold Detection
Why the LT1711CMS8#PBF fits ToF/LIDAR detection: the 4.5 ns propagation delay at 20 mV overdrive is fast enough to resolve return-pulse timing on the order of tens of picoseconds when combined with sub-ns TDC downstream logic, and the rail-to-rail input common-mode range accepts photodiode-amplifier outputs that swing from near ground to near the positive rail. How it is used and what to consider: the comparator is placed at the output of a transimpedance amplifier (TIA) stage, where it converts the analog return-pulse amplitude into a sharp logic-edge timing marker for the time-to-digital converter. The latch pin is held low during the active receive window and pulsed high only after the timing measurement has been latched by the TDC, so the comparator remains transparent during the measurement and freezes afterward. Designers should add a small hysteresis network (typically 1-10 mV via positive feedback) at the inputs to prevent chattering on slow-rising returns and ensure the input trace lengths are kept under 5 mm to preserve the 4.5 ns edge fidelity.
Empfohlen
High-Speed Instrumentation Trigger
Why the LT1711CMS8#PBF fits high-speed instrumentation: a 4.5 ns propagation delay and TTL/CMOS-compatible outputs allow the comparator to drive FPGA trigger logic directly with negligible skew, and the rail-to-rail inputs accept signals from any front-end amplifier regardless of its common-mode bias. How it is used and what to consider: place the LT1711 between the analog signal-conditioning chain and the FPGA's LVTTL trigger input, with the comparator output generating the edge that arms the digitizer's acquisition window. The complementary outputs are useful because one output can be routed to the trigger logic while the other feeds a status LED or monitor pin without an external inverter. The latch pin enables a 'snapshot' trigger mode where the comparator decision is frozen while the FPGA processes a prior event. Designers must place 0.1 µF decoupling capacitors within 3 mm of V+ and V-, and route the input pair as a tightly coupled differential pair to avoid converting common-mode noise into timing jitter.
Empfohlen
Line Receiver and Signal Restoration
Why the LT1711CMS8#PBF fits line-receiver applications: the 4.5 ns propagation delay is well below the bit period of typical 100 Mbps to 200 Mbps signaling, and the rail-to-rail input range allows the receiver to correctly interpret attenuated signals whose DC common-mode has shifted due to AC coupling. How it is used and what to consider: the comparator slices the incoming differential or single-ended data stream at the 50% threshold, recovering clean digital edges from a degraded analog waveform. The complementary outputs let the designer tap both polarities for differential signaling protocols without an external inverter stage. The latch pin can be used to implement a 1-bit oversampling decision stage where the comparator samples twice per bit. Designers should bias the non-inverting input to the receiver's decision threshold (typically V+ / 2 for 3.3 V systems) and add hysteresis of 5-10 mV to prevent chatter on slow edges - the LT1711 datasheet application section shows the standard 3-resistor hysteresis network.
Empfohlen
Motor Control Current-Sense Zero-Cross Detection
Why the LT1711CMS8#PBF fits zero-cross detection in motor drives: the 4.5 ns response time makes the zero-crossing event detectable with minimal phase delay, and the rail-to-rail input range lets the comparator work directly off a low-voltage current-sense amplifier output without requiring a level-shifting front-end. How it is used and what to consider: the comparator monitors the output of a current-sense amplifier across a shunt resistor in the H-bridge, generating a logic transition each time the phase current crosses zero - this signal is fed back to the controller to synchronize the PWM commutation events. The complementary outputs are useful for driving both the high-side and low-side gate-driver enable logic. The latch pin should be tied low (transparent mode) during the active commutation cycle, since the comparator must track the current waveform continuously. Designers should add common-mode filtering at the inputs to reject the large dV/dt transients present on the switching node, and keep the comparator input traces short to avoid coupling noise from the gate-driver outputs.
Empfohlen
Clock and Data Recovery Decision Circuit
Why the LT1711CMS8#PBF fits CDR decision circuits: the 4.5 ns propagation delay supports data rates into the low hundreds of Mbps, and the complementary outputs naturally provide the in-phase and inverted data signals needed by many CDR state machines. How it is used and what to consider: the comparator acts as the slicer in a CDR loop, comparing the equalized data waveform against the recovered-clock-centered threshold and producing a clean retimed data output. The latch pin enables a 'bang-bang' phase detector topology where the comparator samples once per bit and freezes the decision while the PLL integrator updates. Designers should match the propagation delay of the two complementary paths if both outputs feed downstream decision logic, and add 2-5 mV of hysteresis to avoid the noise-induced chatter that would otherwise appear at the slicer output and degrade the CDR jitter performance.
Empfohlen
Battery Voltage and Threshold Monitoring
Why the LT1711CMS8#PBF fits threshold monitoring: the wide 2.4 V to 12 V single-supply range allows the comparator to operate directly from a multi-cell battery stack without requiring a separate regulator, and the rail-to-rail inputs let the threshold be set anywhere within the supply range. How it is used and what to consider: the comparator monitors a divided-down battery voltage against an internal reference, generating a logic-low alarm when the battery voltage falls below the safe-discharge threshold. The complementary outputs can drive both the MCU interrupt input and a low-side disconnect FET gate driver. The latch pin can be used to make the alarm sticky - once the battery drops below the threshold, the comparator output stays latched low until the MCU explicitly resets it. Designers must add hysteresis (10-50 mV depending on the resistor divider values) to prevent alarm chattering at the threshold, and place a small RC filter at the input to reject switching noise from the power stage.
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Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für LT1711CMS8#PBF – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt | LT1711IMS8 | LT1711CMS8 | LT1716CMS8#PBF | LT1715CMS8#PBF |
|---|---|---|---|---|---|
| Package | 8-pin MSOP (CMS8) | 8-pin MSOP - same | 8-pin MSOP - same | 8-pin MSOP - same | 8-pin MSOP - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Propagation Delay | 4.5 ns @ 20 mV OD | 4.5 ns @ 20 mV OD | 4.5 ns @ 20 mV OD | 4.5 ns @ 20 mV OD | 9 ns @ 20 mV OD |
| Input Common-Mode Range | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail |
| Output Type | CMOS/TTL Complementary | CMOS/TTL Complementary | CMOS/TTL Complementary | CMOS/TTL Complementary | CMOS Complementary |
| Latch / Shutdown Pin | Latch (LE) | Latch (LE) | Latch (LE) | Shutdown (SHDN) | None |
| Supply Voltage (Single) | 2.4 V to 12 V | 2.4 V to 12 V | 2.4 V to 12 V | 2.4 V to 12 V | 1.3 V to 11 V |
| Quiescent Current | 17 mA | 17 mA | 17 mA | 17 mA | 2 mA |
| Temperature Grade | Commercial (0 to +70 C) | Industrial (-40 to +85 C) | Commercial (0 to +70 C) | Commercial (0 to +70 C) | Commercial (0 to +70 C) |
Wichtigste Unterscheidungsmerkmale
- Sub-5 ns propagation with rail-to-rail inputs in MSOP-8 (vs. LT1715CMS8#PBF)
- Built-in output latch pin for pipelined architectures (vs. LT1716CMS8#PBF)
- Industrial temperature grade option with identical die (vs. LT1711IMS8)
Designhinweise
Place 0.1 µF decoupling capacitors as close as possible (within 3 mm) to the V+ and V- pins, with a 10 µF bulk capacitor on the supply rail nearby. The 4.5 ns propagation delay is fast enough that supply-rail inductance will appear as ringing on the output edge - keep the supply loop area minimal. Route the two input traces as a tightly coupled differential pair to reject common-mode noise; mismatched trace lengths convert common-mode transients into apparent differential signals at the comparator input.
Add 1-10 mV of hysteresis via positive feedback on the non-inverting input to prevent chatter on slow-rising signals. The standard 3-resistor network shown in the LT1711 datasheet (two resistors from output to non-inverting input plus a third from input to ground) provides stable thresholding and is preferred over a single resistor for symmetric switching thresholds. For applications with 5 mV overdrive or less, hysteresis becomes essential - without it the propagation delay increases and the output may oscillate.
Do not leave the LE (latch enable) pin floating - it must be tied low for normal comparator operation or driven high to freeze the output. A floating LE pin picks up noise and causes erratic output behavior. Also, note that the LT1711CMS8#PBF and LT1711CMS8 differ only in lead finish (PBF = Pb-free); they are electrically identical and share the same datasheet. When ordering for production, verify whether the design requires lead-free compliance - using the non-PBF part in a lead-free assembly will fail the reflow profile.
Compliance-Informationen
PBF suffix confirms lead-free and RoHS compliance per Analog Devices part numbering convention. Operating temperature range 0-70 °C (commercial C grade); the IMS8 variant is industrial-grade (-40 to +85 °C).
