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STMicroelectronics 74LCX373TTR
- Part No.:
- 74LCX373TTR
- Manufacturer:
- STMicroelectronics
- Category:
- Latches
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
74LCX373TTR.pdf
- Description:
- IC D-TYPE TRANSP SGL 8:8 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,612
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Product details
Overview
74LCX373TTR from STMicroelectronics is a low-voltage CMOS octal D-type latch with non-inverting 3-state outputs, 5V-tolerant I/O, and latch-enable/output-enable control. It operates from 2.0V to 3.6V, delivers 8.0 ns max propagation delay at 3V, supports ±24 mA output drive, and features symmetrical output impedance and power-down protection. Used in 3.3V bus interface and data latching between mixed-voltage domains (e.g., 3.3V logic driving 5V peripherals).
For engineers reviewing the 74LCX373TTR datasheet, 74LCX373TTR pinout, 74LCX373TTR application, or 74LCX373TTR equivalent, key selection criteria include 5V-tolerant I/O compatibility, 3.3V supply operation with 24 mA drive strength, latch timing parameters (tPLH/tPHL ≤ 8.0 ns), high-impedance output control via OE, and TSSOP-20 package thermal and routing constraints.
Technical Context
The device implements eight independent D-type latches with shared LE (latch enable) and OE (output enable) controls. Latching occurs on LE transition from HIGH to LOW, capturing Dn inputs synchronously without clock edge dependency. Outputs enter high-impedance state when OE is HIGH, enabling bidirectional bus sharing.
All inputs and outputs tolerate 0–5.5 V regardless of VCC (2.0–3.6 V), enabling safe interfacing with legacy 5V systems. The sub-micron C2MOS process ensures latch-up immunity >500 mA (JESD17) and ESD robustness (HBM >2 kV, MM >200 V), critical for industrial board-level reliability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.0 V to 3.6 V - Enables direct use in 3.3 V systems with 1.5 V data retention during sleep. |
| tPD (max) | 8.0 ns at VCC = 3.0–3.6 V - Matches AC/ACT speed at half the supply voltage, reducing dynamic power. |
| IOL / IOH | ±24 mA at VCC = 3.0–3.6 V - Drives standard PCI bus loads and multiple TTL inputs without external buffers. |
| VI / VO Tolerance | 0–5.5 V - Allows direct connection to 5 V signal sources/sinks without level shifters. |
| IOZ Leakage | ±5 µA - Ensures minimal bus leakage in high-impedance state, preserving signal integrity on shared lines. |
| tW (LE Pulse) | 3.3 ns min at VCC ≥ 3.0 V - Supports fast latch strobing in high-speed control sequences. |
Pinout & Package
TSSOP-20 package: 6.5 mm × 4.4 mm body, 0.65 mm pitch, 1.05 mm max height, lead-free and RoHS compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | OE | Active-low 3-state output enable - disables all Q outputs to high-Z when HIGH. |
| 2,5,6,9,12,15,16,19 | D0–D7 | Data inputs - sampled and latched on LE falling edge; 5V tolerant. |
| 3,4,7,8,13,14,17,18 | Q0–Q7 | Non-inverting latched outputs - driven low/high or placed in high-Z per OE/LE states. |
| 11 | LE | Latch enable - rising edge has no effect; latching occurs on falling edge (synchronous capture). |
| 10 | GND | Ground reference - must be connected to system 0 V plane for noise immunity and ESD path. |
| 20 | VCC | Positive supply - powers internal logic and output drivers; decoupling capacitor required near pin. |
Key Features
| Feature | Design Value |
|---|---|
| 5V-tolerant I/O | Inputs and outputs withstand 0–5.5 V regardless of VCC (2.0–3.6 V), eliminating level translators in mixed-voltage designs. |
| Symmetrical output drive | |IOH| = IOL = 24 mA min at VCC = 3.0–3.6 V - ensures matched rise/fall times and clean signal edges on capacitive buses. |
| Power-down protection | Input and output pins remain high-impedance and current-limited during VCC = 0 V - prevents back-driving and latch-up in unpowered subsystems. |
| Low propagation skew | tOSLH / tOSHL ≤ 1.0 ns - guarantees simultaneous output transitions across all 8 bits, critical for parallel data integrity. |
Applications
| PCI Bus Interface | Memory Address Latching |
|---|---|
|
Use Scenario: Interfacing a 3.3 V microcontroller to a 5 V PCI slot for configuration register access. IC Role / Device Role / Timing Role: Octal latch buffers address/data lines while maintaining 5 V tolerance and precise LE-controlled sampling. Use Value: Eliminates discrete level shifters; meets PCI timing requirements (tW ≥ 3.3 ns, tPD ≤ 8.0 ns) with single-supply operation. |
Use Scenario: Capturing 8-bit address segments from an FPGA before memory read/write cycles. IC Role / Device Role / Timing Role: Synchronizes asynchronous address signals using LE strobe, holding stable values during memory access windows. Use Value: Provides deterministic setup/hold (tS = 2.5 ns, th = 1.5 ns) and low skew (<1 ns) across all bits for reliable address decoding. |
| Industrial I/O Expansion | Legacy System Glue Logic |
|
Use Scenario: Adding isolated digital input latching to a 3.3 V PLC CPU handling 5 V sensor signals. IC Role / Device Role / Timing Role: Accepts 5 V sensor outputs directly, latches status on LE edge, and presents clean 3.3 V levels to MCU GPIO. Use Value: Reduces BOM count by integrating voltage tolerance, latching, and 3-state buffering - no external resistors or clamps needed. |
Use Scenario: Replacing obsolete 74F373 in retro-computing hardware upgrades requiring lower power and same pinout. IC Role / Device Role / Timing Role: Drop-in functional replacement with identical LE/OE control, D-to-Q behavior, and TSSOP-20 footprint. Use Value: Maintains legacy timing margins (tPD ≤ 8.0 ns vs. F-series 10 ns) while cutting ICC quiescent current by >60% at 3.3 V. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal D-type latch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74LVC373PW | Lower VCC range (1.65–3.6 V); 24 mA drive only at VCC ≥ 3.0 V; no guaranteed 5 V tolerance - requires external clamping for 5 V inputs. | Best suited for pure 3.3 V or 2.5 V systems where 5 V I/O is absent; not recommended for PCI or mixed-voltage buses. | Select when cost or availability favors NXP; verify input protection if interfacing >3.6 V sources. |
| SN74LVTH373PWR | Higher drive (±64 mA), but only 3.3 V tolerant (VI max = 4.6 V); no power-down protection; higher ICC (20 µA vs. 10 µA). | Targeted at high-fanout 3.3 V bus driving (e.g., memory buffers), not 5 V interfacing; lacks safe zero-VCC operation. | Choose for demanding 3.3 V loads where extra drive margin is needed; avoid in 5 V-coupled systems. |
Compared with 74LVC373PW and SN74LVTH373PWR, the 74LCX373TTR uniquely combines guaranteed 5 V I/O tolerance, power-down protection, and sub-8 ns propagation at 3 V - making it the only option qualified for legacy bus bridging without redesign.
Availability
74LCX373TTR is available at Aetrix Electronics and suitable for PCI bus interface, memory address latching, and industrial I/O expansion requiring stable component supply, long-term lifecycle support, and RoHS-compliant TSSOP packaging.
Supply support for 74LCX373TTR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, MCU, power, and discrete components for automotive, industrial, and consumer markets.
The 74LCX logic family targets low-voltage, high-speed 3.3 V system interfacing with 5 V legacy compatibility - optimized for reduced power, enhanced noise immunity, and seamless integration into mixed-signal embedded platforms.
FAQ
Can 74LCX373TTR operate with VCC = 2.5 V while interfacing 5 V inputs?
Yes. The device is fully specified for VCC = 2.0–3.6 V and guarantees 5 V-tolerant inputs (VI = 0–5.5 V) across that entire range. At 2.5 V supply, VIH remains 2.0 V and VIL stays 0.8 V, ensuring reliable logic recognition of 5 V signals without external biasing or clamping diodes.
What is the maximum capacitive load the outputs can drive while maintaining tPD ≤ 8.0 ns?
The 8.0 ns max tPD is measured with CL = 50 pF and RL = 500 Ω per AC specification. Driving loads beyond 50 pF increases propagation delay nonlinearly; for 75 pF, typical tPD rises to ~9.5 ns. For heavier loads, add series termination or reduce trace length to maintain timing margins.
Does OE assertion override latched data on Q outputs?
Yes. When OE is HIGH, all Q0–Q7 outputs enter high-impedance state regardless of LE state or stored data. This allows multiple 74LCX373TTR devices to share a common bus. OE takes precedence over LE - latched data remains internally preserved but electrically disconnected from the pins.
Is the TSSOP-20 package suitable for reflow soldering per JEDEC J-STD-020?
Yes. The 74LCX373TTR TSSOP-20 package is rated for standard Pb-free reflow profiles (peak 260 °C, 10 sec max). Its moisture sensitivity level is MSL3, requiring bake-out only if exposed to ambient >30 °C/60% RH for >168 hours - consistent with industrial PCB assembly practices.
74LCX373TTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- 74LCX
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- D-Type Transparent Latch
- Circuit:
- 8:8
- Output Type:
- Tri-State
- Voltage - Supply:
- 2V ~ 3.6V
- Independent Circuits:
- 1
- Delay Time - Propagation:
- 1.5ns
- Current - Output High, Low:
- 24mA, 24mA
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
74LCX373TTR FAQ
1.How can I place an order for 74LCX373TTR through Aetrix?
Please submit a Request for Quotation (RFQ) for 74LCX373TTR 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 74LCX373TTR reliable?
The price and inventory of 74LCX373TTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LCX373TTR is usually 5 days.
3.What payment methods are accepted for 74LCX373TTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LCX373TTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74LCX373TTR?
74LCX373TTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74LCX373TTR 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 74LCX373TTR?
For technical support, including 74LCX373TTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LCX373TTR requirements.
6.How does Aetrix verify that 74LCX373TTR is sourced from the original manufacturer or authorized distributors?
All 74LCX373TTR 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 74LCX373TTR meets industry standards.
7.What is the process for return or replacement of 74LCX373TTR?
All 74LCX373TTR units undergo pre-shipment inspection (PSI). If there is an issue with 74LCX373TTR, 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 74LCX373TTR part is unused and in its original packaging.
Return procedure for 74LCX373TTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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