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Analog Devices Inc. LT1394IS8#TRPBF
- Part No.:
- LT1394IS8#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Comparators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LT1394IS8#TRPBF.pdf
- Description:
- IC COMPARATOR 1 W/LATCH 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,190
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Product details
Overview
LT1394IS8#TRPBF from Analog Devices (formerly Linear Technology) is an ultrafast, ground-sensing comparator with complementary TTL/CMOS outputs and internal latch functionality. It delivers 7ns propagation delay, 0.8mV input offset voltage, and operates from single 5V or dual ±5V supplies. Its input common-mode range extends to the negative rail - enabling current-sense applications in switching regulators and high-speed zero-crossing detection.
For engineers reviewing the LT1394IS8#TRPBF datasheet, LT1394IS8#TRPBF pinout, LT1394IS8#TRPBF application, or LT1394IS8#TRPBF equivalent, this page provides verified electrical parameters, latch timing behavior, ground-sensing input operation, SO-8 package mechanical data, and validated alternatives for high-speed comparator selection in precision timing, A/D front-ends, and adaptive trigger circuits.
Technical Context
The LT1394IS8#TRPBF uses a PNP differential input stage enabling rail-to-rail negative common-mode operation down to V–, with no minimum input slew rate requirement. Its output stage provides active drive in both directions into TTL, CMOS, or passive loads, minimizing cross-conduction current and ensuring stable response even during slow input transitions.
It integrates a TTL/CMOS-compatible latch controlled by Pin 5 (LATCH ENABLE), with guaranteed 6ns latch propagation delay, –0.4ns setup time, and 2ns hold time. The latch retains output state while LATCH is high, and new input data appears at outputs within 6ns after LATCH goes low - independent of supply voltage variation across –5V to –2V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Propagation Delay (tPD) | 7ns typical (100mV step, 5mV overdrive); enables sub-10ns decision timing in high-speed sampling and pulse discrimination. |
| Input Offset Voltage (VOS) | 0.8mV max (–40°C to 85°C); supports precision threshold detection in current-sense and V/F converter applications. |
| Supply Range | Single 5V or dual ±5V; allows flexible integration in mixed-supply systems without level-shifting circuitry. |
| Input Common-Mode Range | –5V to +3.5V on ±5V supplies; permits direct sensing of signals referenced to ground or negative rails. |
| Latch Propagation Delay (tLPD) | 6ns max; ensures deterministic data capture timing for synchronous sampling and gated measurement systems. |
| Output Drive | ±4mA sink/source (VOH = 2.4V min, VOL = 0.5V max); directly interfaces to TTL/CMOS logic without external buffers. |
| Quiescent Current | 6mA positive supply current (I+), 1.2mA negative supply current (I–); balances speed and power in battery-sensitive or thermally constrained designs. |
Pinout & Package
LT1394IS8#TRPBF is housed in an 8-lead plastic SO (SO-8) package, 3.9mm × 4.9mm body, 1.27mm lead pitch, with gull-wing leads. RoHS-compliant, Pb-free, and rated for –40°C to +85°C operating temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| V+ (Pin 1) | Positive supply input | Accepts 4.6V–5.4V (single 5V) or up to +7V (dual supply); powers internal bias and output stages. |
| +IN (Pin 2) | Noninverting input | High-impedance PNP input; accepts signals down to V– without phase reversal or damage. |
| –IN (Pin 3) | Inverting input | Matches +IN in voltage range and overvoltage tolerance; enables differential or single-ended configurations. |
| V– (Pin 4) | Negative supply input | Supports 0V (single supply) or –5V (dual supply); defines lower bound of input common-mode range. |
| LATCH ENABLE (Pin 5) | Asynchronous latch control | Active-high TTL/CMOS-compatible signal; holds Q and Q̅ outputs when high, releases on falling edge. |
| GND (Pin 6) | Ground reference | Return path for bias currents and output loads; must be low-inductance connection for stability. |
| Q OUT (Pin 7) | Noninverting logic output | Active-high TTL/CMOS output; high when +IN > –IN and LATCH ENABLE is low. |
| Q OUT (Pin 8) | Inverting logic output | Active-low TTL/CMOS output; complements Q OUT; enables direct connection to flip-flop clock inputs. |
Key Features
| Feature | Design Value |
|---|---|
| UltraFast™ 7ns propagation delay | Enables reliable decision-making in 100+ MHz sampling systems and fast pulse-width discriminators. |
| Ground-sensing input architecture | Allows direct interface to shunt resistors in switching regulator feedback paths without level shifters. |
| Internal latch with TTL/CMOS compatibility | Eliminates need for external D-latches in gated acquisition, reducing board area and propagation uncertainty. |
| No minimum input slew rate requirement | Stable operation with slow-rising signals (e.g., sine-wave zero crossings), unlike many comparators requiring >1V/ns. |
| Inputs exceed supplies without phase reversal | Withstands transient overvoltage up to ±12V differential or beyond supplies (≤10mA), improving system robustness. |
| Pin compatibility with LT1016/LT1116/LT1671 | Facilitates drop-in upgrade path in legacy designs using those comparators, preserving PCB layout. |
Applications
| High-Speed A/D Converter Front-End | Switching Regulator Current Sense |
|---|---|
Use Scenario: Sampling analog input at ≥20 MSPS using flash or pipeline ADC architectures where comparator settling dominates conversion time. IC Role / Device Role / Timing Role: LT1394IS8#TRPBF serves as the first-stage quantizer, comparing input against reference ladder voltages with minimal aperture jitter. Use Value: 7ns tPD and <2.2ns differential delay reduce timing skew between parallel comparators, improving ENOB in multi-bit flash converters. |
Use Scenario: Monitoring MOSFET source current in synchronous buck converters to enable cycle-by-cycle overcurrent protection. IC Role / Device Role / Timing Role: LT1394IS8#TRPBF compares shunt voltage against a programmable threshold, triggering gate driver shutdown within nanoseconds. Use Value: Ground-sensing input allows direct connection to low-side shunt; 0.8mV VOS enables accurate 10mΩ shunt use at 1A full-scale. |
| Adaptive Line Receiver Trigger | Crystal Oscillator Feedback Amplifier |
Use Scenario: Converting variable-amplitude, DC-offset-prone signals from fiber-optic or coaxial line receivers into clean digital clocks. IC Role / Device Role / Timing Role: LT1394IS8#TRPBF acts as adaptive threshold detector, with its latch holding valid data during amplitude dips or noise bursts. Use Value: Latch function maintains last valid state during signal fade; input rail-to-rail range accommodates wide dynamic input swings without clamping diodes. |
Use Scenario: Providing gain and phase margin in Pierce-type crystal oscillator circuits for 1–30MHz fundamental or overtone operation. IC Role / Device Role / Timing Role: LT1394IS8#TRPBF functions as high-gain, low-noise inverter in the oscillator loop, sustaining oscillation with minimal phase noise. Use Value: 1600V/V small-signal gain and 7ns delay ensure reliable startup and low-jitter output; complementary outputs simplify buffer interfacing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-speed comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1016CS8#PBF | Slower (10ns tPD), higher VOS (1.5mV), no latch, same SO-8 pinout | Lacks latch functionality and ground-sensing capability; unsuitable for current-sense or gated sampling. | Select when latch and rail-to-rail input are unnecessary and cost sensitivity outweighs speed requirements. |
| ADCMP572BCPZ-R2 | Faster (4.5ns tPD), ECL/PECL outputs, requires negative supply, different pinout | Requires level translation for TTL/CMOS interfacing; not pin-compatible; higher power (25mA). | Select only when sub-5ns timing is mandatory and system already supports ECL logic levels and layout. |
Compared with LT1016CS8#PBF and ADCMP572BCPZ-R2, the LT1394IS8#TRPBF uniquely combines 7ns speed, integrated latch, ground-sensing input, and TTL/CMOS compatibility in SO-8 - making it optimal for cost-sensitive, space-constrained, and latch-dependent high-speed comparator applications.
Availability
LT1394IS8#TRPBF is available at Aetrix Electronics and suitable for high-speed A/D converter front-ends, switching regulator current-sense protection, and adaptive line receiver designs requiring stable component supply across industrial temperature ranges.
Supply support for LT1394IS8#TRPBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices acquired Linear Technology in 2017 and maintains full product support, datasheet documentation, and long-term manufacturing commitment for all LT-branded components.
The LT1394IS8#TRPBF belongs to Linear Technology's UltraFast™ comparator family, designed specifically for applications demanding nanosecond decision timing, latch retention, and robust input handling in power management, test equipment, and communications infrastructure.
FAQ
What is the guaranteed operating temperature range for the LT1394IS8#TRPBF?
The LT1394IS8#TRPBF is specified and tested over –40°C to +85°C, with all key parameters including propagation delay, offset voltage, and latch timing validated across this extended industrial temperature range - unlike the commercial-grade LT1394CS8 variant.
Does the LT1394IS8#TRPBF require external pull-up resistors on its Q and Q̅ outputs?
No. The LT1394IS8#TRPBF features actively driven complementary TTL/CMOS outputs capable of sourcing 4mA and sinking 10mA. External pull-ups are unnecessary and would degrade switching speed and increase power consumption.
Can the LT1394IS8#TRPBF operate from a single 3.3V supply?
No. The LT1394IS8#TRPBF is not characterized for 3.3V operation. Its absolute maximum positive supply is 7V, but the datasheet specifies performance only for single 5V (4.6V–5.4V) or dual ±5V supplies. Operation outside these conditions risks parameter degradation or latch instability.
How does the latch function behave when the LATCH ENABLE pin is left floating?
The LATCH ENABLE pin of the LT1394IS8#TRPBF has internal weak pull-up, causing it to float high. If unconnected, the latch remains continuously enabled - freezing Q and Q̅ outputs regardless of input changes. For normal comparator operation, tie LATCH ENABLE to GND unless latching is explicitly required.
Is the LT1394IS8#TRPBF pin-compatible with the LT1671IS8#TRPBF?
Yes. The LT1394IS8#TRPBF shares identical SO-8 pinout, supply configuration, and complementary output structure with the LT1671IS8#TRPBF. Both support single 5V/dual ±5V operation and ground-sensing inputs, enabling direct replacement where 7ns speed suffices over LT1671's 4.5ns rating.
LT1394IS8#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- UltraFast™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- with Latch
- Number of Elements:
- 1
- Output Type:
- CMOS, Complementary, TTL
- Voltage - Supply, Single/Dual (±):
- -
- :
- 2.5mV @ ±5V
- Voltage - Input Offset (Max):
- 4.5µA @ ±5V
- Current - Input Bias (Max):
- 20mA
- Current - Output (Typ):
- 8.5mA
- Current - Quiescent (Max):
- 100dB CMRR, 100dB PSRR
- CMRR, PSRR (Typ):
- 9ns
- Propagation Delay (Max):
- -
- Hysteresis:
- -40°C ~ 85°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Surface Mount
- :
- 8-SO
LT1394IS8#TRPBF FAQ
1.How can I place an order for LT1394IS8#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1394IS8#TRPBF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LT1394IS8#TRPBF reliable?
The price and inventory of LT1394IS8#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1394IS8#TRPBF is usually 5 days.
3.What payment methods are accepted for LT1394IS8#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1394IS8#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1394IS8#TRPBF?
LT1394IS8#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1394IS8#TRPBF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LT1394IS8#TRPBF?
For technical support, including LT1394IS8#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1394IS8#TRPBF requirements.
6.How does Aetrix verify that LT1394IS8#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT1394IS8#TRPBF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LT1394IS8#TRPBF meets industry standards.
7.What is the process for return or replacement of LT1394IS8#TRPBF?
All LT1394IS8#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1394IS8#TRPBF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LT1394IS8#TRPBF part is unused and in its original packaging.
Return procedure for LT1394IS8#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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