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Nexperia USA Inc. 74HCT4538PW,118
- Part No.:
- 74HCT4538PW,118
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Multivibrators
- Package:
- 16-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
74HCT4538PW,118.pdf
- Description:
- IC MULTIVIBRATOR 35NS 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,359
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Product details
Overview
74HCT4538PW,118 from Nexperia is a dual retriggerable-resettable precision monostable multivibrator in TSSOP16 package, operating from 4.5 V to 5.5 V over -40 °C to +125 °C. Each channel delivers programmable pulse width (TW = 0.7 × REXT × CEXT) with ±0.2 % typical temperature stability, edge-triggered inputs (rising or falling), and independent active-low reset (nCD). It serves as a timing generator in digital control logic, debounce circuits, and pulse shaping for industrial sensor interfaces.
For engineers reviewing the 74HCT4538PW,118 datasheet, 74HCT4538PW,118 pinout, 74HCT4538PW,118 application, or 74HCT4538PW,118 equivalent, key selection criteria include external timing component dependency, Schmitt-trigger input tolerance for slow edges, TTL-compatible input thresholds, dual-channel independence, and reset-driven pulse termination capability.
Technical Context
The device implements two independent monostable circuits, each with dual trigger inputs (nA for falling-edge, nB for rising-edge), a dedicated active-low reset (nCD), and complementary outputs (nQ/nQ). Pulse width is externally set via REXT and CEXT connected to nREXT/CEXT and nCEXT pins, with linear design ensuring precise timing control.
Inputs feature Schmitt-trigger action for noise immunity and compatibility with slow-rising/falling signals; clamp diodes allow interface to voltages exceeding VCC using current-limiting resistors. The circuit supports retriggering during an active output pulse, enabling pulse extension without requiring full timeout completion.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - Ensures compatibility with standard 5 V TTL/CMOS systems and stable operation across industrial voltage tolerances. |
| Operating Temperature | -40 °C to +125 °C - Qualified for extended industrial and under-hood automotive-adjacent environments without derating. |
| Pulse Width Accuracy | ±0.2 % typical over temperature - Enables high-reliability timing where drift must remain below 1 μs per ms of nominal width. |
| Propagation Delay | 30 ns (typ) at VCC = 5.0 V, CL = 15 pF - Supports sub-33 MHz timing resolution in synchronous digital control loops. |
| Input Thresholds | VIH = 2.0 V min, VIL = 0.8 V max at VCC = 4.5 V - Guarantees robust TTL-level signal recognition with margin against noise. |
| Output Drive | ±4.0 mA at VOH/VOL - Sufficient to directly drive multiple 74HCT inputs or small capacitive loads without buffering. |
| Power Dissipation | 8.0 μA ICC (typ) at VCC = 5.5 V - Enables low-quiescent-power timing in battery-backed or energy-constrained subsystems. |
Pinout & Package
TSSOP16 plastic thin shrink small outline package (SOT403-1); 16 leads; body width 4.4 mm; lead pitch 0.65 mm; RoHS-compliant; moisture sensitivity level MSL3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 15 (1CEXT, 2CEXT) | External capacitor connection | Must be tied to GND; forms timing network with REXT to define pulse width (TW = 0.7 × REXT × CEXT). |
| 2, 14 (1REXT/CEXT, 2REXT/CEXT) | External resistor/capacitor node | Connects to REXT; combined with CEXT at Pin 1/15 sets monostable timing for respective channel. |
| 3, 13 (1CD, 2CD) | Direct reset input | Active-LOW asynchronous termination - forces nQ LOW and nQ HIGH immediately, overriding ongoing pulse. |
| 4, 12 (1B, 2B) | Rising-edge trigger input | Triggers monostable on LOW→HIGH transition; Schmitt-triggered for noise immunity on slow edges. |
| 5, 11 (1A, 2A) | Falling-edge trigger input | Triggers monostable on HIGH→LOW transition; independent of nB, enabling dual-edge flexibility per channel. |
| 6, 10 (1Q, 2Q) | True output | Active-HIGH output pulse with duration defined by REXT/CEXT; complements nQ output. |
| 7, 9 (1Q, 2Q) | Complementary output | Active-LOW output synchronized to nQ; provides both logic polarities for interfacing with diverse downstream logic. |
| 8 | GND | Reference ground for all internal circuitry and external timing components. |
| 16 | VCC | Positive supply rail; decoupling capacitor recommended within 10 mm of this pin for stable timing. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent monostables | Enables two separate timing functions (e.g., delay + pulse stretch) on one IC without crosstalk or shared timing components. |
| Retriggerable & resettable operation | Allows dynamic pulse extension during active output and immediate forced termination via nCD - critical for fault-responsive timing. |
| Schmitt-trigger inputs | Accepts input rise/fall times up to 139 ns/V (at VCC = 4.5 V), eliminating need for external signal conditioning in noisy industrial environments. |
| TTL-compatible input levels | VIH = 2.0 V min / VIL = 0.8 V max ensures direct interoperability with legacy 5 V TTL logic families without level shifters. |
| Wide temperature range support | Specified from -40 °C to +125 °C with no parameter derating - suitable for uncooled industrial controllers and motor drives. |
Applications
| Industrial Sensor Debounce | Digital Control Timing |
|---|---|
Use Scenario: Mechanical switch or encoder output in PLC I/O modules subject to contact bounce or EMI-induced glitches. IC Role / Device Role / Timing Role: Monostable channel acts as hardware-based debouncer, generating clean, fixed-duration pulses after first valid edge. Use Value: Eliminates microcontroller polling or software filtering; guarantees ≤100 ns jitter and deterministic response regardless of bounce duration. | Use Scenario: Synchronization of actuator enable signals in motor control subsystems requiring precise dead-time insertion. IC Role / Device Role / Timing Role: Dual channels generate complementary delayed enables with adjustable overlap/blanking windows. Use Value: Prevents shoot-through in half-bridge drivers; timing accuracy ±0.2 % ensures consistent dead-time across temperature and supply variation. |
| Pulse Width Modulation Preconditioning | Legacy System Interface Adapter |
Use Scenario: Converting variable-frequency, variable-duty-cycle signals from analog comparators into fixed-width pulses for digital counters. IC Role / Device Role / Timing Role: Retriggerable monostable converts irregular input trains into uniform-width pulses while preserving frequency information. Use Value: Enables accurate frequency measurement using simple gated-count logic; retriggering prevents pulse dropout during high-frequency bursts. | Use Scenario: Interfacing vintage 5 V TTL test equipment with modern FPGA-based controllers lacking native Schmitt inputs. IC Role / Device Role / Timing Role: Provides edge-controlled pulse generation and level translation with noise-immune inputs. Use Value: Replaces discrete RC+logic solutions; eliminates timing skew between channels and reduces board space by >60 % vs. discrete implementation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar monostable multivibrator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74HC4538PW,118 | CMOS version; wider VCC range (2–6 V); higher input impedance; lower drive strength (±4 mA vs. ±4 mA HCT); identical pinout and function. | Preferred in mixed-voltage systems or battery-powered designs where 5 V supply is not guaranteed; less suitable for driving heavy capacitive loads. | Select when operating below 4.5 V or requiring ultra-low static current (<1 μA); verify timing stability across full VCC range. |
| SN74LS423N | Bipolar TTL; fixed 5 V only; higher power consumption (ICC ≈ 25 mA); different pinout; non-retriggerable; requires external RC network per channel. | Used in legacy 74LS-based systems where backward compatibility is mandatory; lacks retrigger/reset flexibility and temperature stability. | Choose only for drop-in replacement in existing LS designs; avoid for new designs due to power, timing accuracy, and feature limitations. |
Compared with 74HC4538PW,118, the HCT variant offers superior noise immunity and TTL-level compatibility at 5 V, while SN74LS423N sacrifices retriggerability and precision for legacy integration - making 74HCT4538PW,118 optimal for new industrial timing designs requiring robustness and flexibility.
Availability
74HCT4538PW,118 is available at Aetrix Electronics and suitable for industrial automation controllers, motor drive timing circuits, and sensor interface modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for 74HCT4538PW,118 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
Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance logic, analog, and MOSFET solutions for industrial, automotive, and computing markets.
The 74HCT series targets industrial-grade 5 V logic interoperability, combining CMOS power efficiency with TTL input compatibility - designed specifically for robust, noise-tolerant digital control in harsh environments.
FAQ
What is the minimum external timing capacitor value supported?
The datasheet specifies no lower limit for CEXT, but practical use begins at ~100 pF. At values below 1 nF, timing accuracy degrades due to parasitic capacitance effects; for reliable sub-microsecond pulses, CEXT ≥ 1 nF and REXT ≥ 2 kΩ are recommended per Figure 11 and Table 7.
Can both trigger inputs (nA and nB) be used simultaneously on one channel?
Yes - nA (falling-edge) and nB (rising-edge) are logically OR'd internally per channel. Either edge triggers the monostable independently, allowing flexible edge detection without external logic. Simultaneous assertion has no adverse effect; the first valid edge initiates the pulse.
How does the reset input (nCD) interact with retriggering?
nCD is asynchronous and dominant: a LOW on nCD terminates the output pulse immediately, regardless of ongoing retrigger activity. After reset release, the channel remains inactive until the next valid trigger edge - retriggering does not resume automatically.
Is a damping diode required for all CEXT values?
A damping diode (e.g., Schottky DEXT) is recommended when CEXT > 100 nF, especially in systems with rapid VCC ramp-down. Larger capacitors store more energy; discharging through input protection diodes during power loss may exceed IIK ratings (±20 mA), risking latch-up or degradation.
74HCT4538PW,118 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- 74HCT
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Logic Type:
- Monostable
- Independent Circuits:
- 2
- Schmitt Trigger Input:
- No
- Propagation Delay:
- 35 ns
- Current - Output High, Low:
- 4mA, 4mA
- Voltage - Supply:
- 4.5 V ~ 5.5 V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP
74HCT4538PW,118 FAQ
1.How can I place an order for 74HCT4538PW,118 through Aetrix?
Please submit a Request for Quotation (RFQ) for 74HCT4538PW,118 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 74HCT4538PW,118 reliable?
The price and inventory of 74HCT4538PW,118 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74HCT4538PW,118 is usually 5 days.
3.What payment methods are accepted for 74HCT4538PW,118?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74HCT4538PW,118 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74HCT4538PW,118?
74HCT4538PW,118 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74HCT4538PW,118 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 74HCT4538PW,118?
For technical support, including 74HCT4538PW,118 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74HCT4538PW,118 requirements.
6.How does Aetrix verify that 74HCT4538PW,118 is sourced from the original manufacturer or authorized distributors?
All 74HCT4538PW,118 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 74HCT4538PW,118 meets industry standards.
7.What is the process for return or replacement of 74HCT4538PW,118?
All 74HCT4538PW,118 units undergo pre-shipment inspection (PSI). If there is an issue with 74HCT4538PW,118, 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 74HCT4538PW,118 part is unused and in its original packaging.
Return procedure for 74HCT4538PW,118:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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