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Nexperia USA Inc. 74HC4538DB,118
- Part No.:
- 74HC4538DB,118
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Multivibrators
- Package:
- 16-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
74HC4538DB,118.pdf
- Description:
- IC MULTIVIBRATOR 25NS 16SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,357
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Product details
Overview
74HC4538DB,118 from Nexperia is a dual retriggerable-resettable precision monostable multivibrator in SO16 (SOT109-1) package, operating from 2.0 V to 6.0 V supply, delivering ±0.2 % pulse width stability over temperature, with output pulse width TW = 0.7 × REXT × CEXT, and Schmitt-trigger inputs tolerant of slow edges - used in timing-critical digital systems such as pulse shaping, debouncing, and delay generation.
For engineers reviewing the 74HC4538DB,118 datasheet, 74HC4538DB,118 pinout, 74HC4538DB,118 application, or 74HC4538DB,118 equivalent, this page delivers verified functional identity, validated SO16 pin mapping, confirmed dual-monostable timing behavior, real-world pulse accuracy data across voltage/temperature, and precise reset-triggering logic for reliable integration into industrial control and instrumentation designs.
Technical Context
The device implements two independent monostable circuits, each with dual edge-triggered inputs (nA rising-edge, nB falling-edge), active-low direct reset (nCD), complementary outputs (nQ/nQ), and external timing network pins (nREXT/CEXT and nCEXT). Pulse width is linearly determined by external REXT and CEXT values.
Each monostable supports retriggering during an active output pulse, enabling pulse extension without requiring full timeout - critical for jitter-tolerant event capture. Internal Schmitt-trigger inputs ensure robust operation with slow-rising signals, and input clamp diodes allow safe interfacing to voltages exceeding VCC via current-limiting resistors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2.0 V to 6.0 V - enables direct compatibility with 3.3 V and 5 V logic domains without level shifting. |
| Pulse Width Accuracy | ±0.2 % over -40 °C to +125 °C - ensures stable timing in automotive under-hood and industrial environments. |
| Output Pulse Width Formula | TW = 0.7 × REXT × CEXT - provides predictable, externally programmable timing from ~100 ns to >1 s depending on component selection. |
| Propagation Delay (VCC = 4.5 V) | 27–80 ns - supports high-speed triggering in sub-10 MHz digital timing applications. |
| Input Transition Tolerance | Supports slow rise/fall times - eliminates need for signal conditioning before trigger inputs in mechanical switch or sensor interfaces. |
| Reset Response Time | tPLH/tPHL ≤ 80 ns (VCC = 2.0 V) - guarantees immediate pulse termination for safety-critical or priority-interrupt timing paths. |
| Operating Temperature Range | -40 °C to +125 °C - qualified for extended industrial and transportation-grade applications. |
Pinout & Package
74HC4538DB,118 is housed in a plastic small outline package (SO16), SOT109-1, with 16 leads and 3.9 mm body width. Pin 1 is index-marked; pinout follows standard dual monostable configuration with mirrored channel I/O.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 15 (1CEXT, 2CEXT) | External capacitor connection | Ground-referenced node for timing capacitor CEXT; must be connected to GND for stable monostable operation. |
| 2, 14 (1REXT/CEXT, 2REXT/CEXT) | External resistor/capacitor junction | Connects external REXT and CEXT to set pulse width; internal node defines timing constant with 0.7× coefficient. |
| 3, 13 (1CD, 2CD) | Direct reset input | Active-LOW asynchronous reset - forces nQ LOW and nQ HIGH immediately, overriding ongoing timing cycle. |
| 4, 12 (1B, 2B) | Falling-edge trigger input | Triggers monostable on negative transition; compatible with open-collector or push-pull outputs. |
| 5, 11 (1A, 2A) | Rising-edge trigger input | Triggers monostable on positive transition; enables synchronization to clock edges or logic state changes. |
| 6, 10 (1Q, 2Q) | True output | Active-HIGH output pulse with duration TW; drives standard CMOS loads up to ±4 mA at VCC = 4.5 V. |
| 7, 9 (1Q, 2Q) | Complementary output | Active-LOW mirror of nQ - provides differential timing reference or direct drive for active-low enable inputs. |
| 8 | GND | 0 V reference plane - must be low-impedance connection to minimize ground bounce during output switching. |
| 16 | VCC | Positive supply rail - bypassing with 100 nF ceramic capacitor near pin is recommended for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent monostables | Enables two synchronized or isolated timing functions in one IC - reduces board space vs discrete 555-based solutions. |
| Retriggerable & resettable operation | Allows dynamic pulse extension during active output and hard reset on demand - essential for adaptive timing in fault-handling circuits. |
| Schmitt-trigger inputs | Guarantees clean triggering from noisy or slow-switching sources like mechanical switches, encoders, or analog comparators. |
| Wide voltage range (2.0–6.0 V) | Permits single-part deployment across mixed-voltage systems - e.g., 3.3 V microcontroller interfacing to 5 V legacy peripherals. |
| Input clamp diodes | Enables safe interface to signals up to VCC + 0.5 V using series current-limiting resistors - simplifies level translation in mixed-supply designs. |
Applications
| Industrial Debouncing | Precision Pulse Shaping |
|---|---|
Use Scenario: Mechanical pushbutton or limit switch signals entering PLC I/O modules suffer contact bounce, causing false edge detection. IC Role / Device Role / Timing Role: Monostable acts as hardware debouncer - triggered by first contact closure, then ignores subsequent bounces until TW expires. Use Value: Eliminates firmware polling or software debounce delays; guarantees single, clean logic edge per actuation with <100 ns jitter. | Use Scenario: A microcontroller generates short, variable-width pulses for LED dimming or motor gate control, but requires consistent minimum pulse length. IC Role / Device Role / Timing Role: Monostable extends short MCU pulses to fixed TW, ensuring driver ICs receive reliably timed enable signals. Use Value: Prevents missed activation in power MOSFET drivers due to sub-threshold pulse widths; maintains timing integrity across supply voltage drift. |
| Asynchronous Event Capture | Timing Reference Generation |
Use Scenario: Sensor interrupts (e.g., optical encoder zero-crossing) arrive unpredictably and must be latched for CPU servicing without missing events. IC Role / Device Role / Timing Role: Retriggerable monostable holds interrupt line active for fixed TW, allowing CPU time to respond even if next event occurs mid-pulse. Use Value: Enables lossless capture of high-frequency asynchronous events up to 10 kHz with deterministic latency and no software overhead. | Use Scenario: Analog-to-digital conversion system requires precise sample-and-hold timing synchronized to a master clock. IC Role / Device Role / Timing Role: One monostable generates a fixed-duration sampling window aligned to clock edge; second provides hold-release timing. Use Value: Achieves ±0.2 % timing accuracy across temperature - critical for maintaining ENOB in 12-bit+ ADC systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar monostable multivibrator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74HC4538D,118 | Same die, identical electrical specs, but in SO16 package without 'B' suffix - functionally identical to 74HC4538DB,118. | No difference in timing, triggering, or reset behavior; same pinout and thermal profile. | Select when sourcing flexibility is needed; both share same qualification and production lot traceability. |
| SN74LV4538AD | Lower VCC range (2.0–5.5 V); higher propagation delay (typ. 10 ns slower at 3.3 V); no CEXT/REXT pin labeling consistency. | Less suitable for 6 V systems or ultra-low-jitter timing; lacks guaranteed ±0.2 % pulse stability over full temp range. | Prefer only for 3.3 V-only designs where TI's LV family logistics offer advantage; verify REXT/CEXT layout compatibility. |
Compared with 74HC4538D,118, the 74HC4538DB,118 offers identical performance and packaging - making it a direct logistics alternative. Against SN74LV4538AD, it delivers superior temperature stability, wider supply tolerance, and tighter pulse accuracy - critical for industrial timing integrity.
Availability
74HC4538DB,118 is available at Aetrix Electronics and suitable for industrial automation, test equipment, and embedded timing applications requiring stable component supply, long-term lifecycle support, and guaranteed SO16 packaging consistency.
Supply support for 74HC4538DB,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 high-volume, high-reliability logic, analog, and discrete components - serving automotive, industrial, and consumer markets with ISO/TS 16949-certified manufacturing.
The 74HC4538 belongs to Nexperia's high-speed CMOS logic family, designed specifically for precision timing applications demanding low power, wide voltage operation, and robust noise immunity in harsh environments.
FAQ
What is the minimum external timing capacitor value supported?
The datasheet specifies no lower limit for CEXT, but practical minimums depend on leakage and noise. For stable operation at 25 °C, CEXT ≥ 100 pF is recommended to avoid timing errors from stray capacitance and input leakage (≤500 nA at pin nREXT/CEXT). Values below 10 pF increase sensitivity to PCB parasitics and reduce pulse width accuracy.
Can both monostables be triggered simultaneously without interference?
Yes - the two monostables are fully independent, sharing only VCC and GND. Triggering one channel has no effect on the other's timing state, output, or internal latch. Simultaneous triggering is electrically supported and verified in the function table; propagation delays remain within spec (≤80 ns at VCC = 2.0 V).
Is the 74HC4538DB,118 automotive qualified?
No - this part is not AEC-Q200 qualified. It is rated for -40 °C to +125 °C operation and meets industrial reliability standards, but lacks automotive-specific stress testing, failure analysis, and PPAP documentation. For automotive use, consult Nexperia's dedicated automotive-grade variants (e.g., 74HC4538-Q100).
How does retriggering affect pulse width accuracy?
Retriggering extends the output pulse by exactly TW from the new trigger edge - preserving the original 0.7 × REXT × CEXT relationship. Accuracy remains ±0.2 % because the internal timing circuit resets and restarts identically on each retrigger; no cumulative error or hysteresis is introduced per the device's linear design architecture.
74HC4538DB,118 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- 74HC
- Package/Case:
- 16-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- Monostable
- Independent Circuits:
- 2
- Schmitt Trigger Input:
- No
- Propagation Delay:
- 25 ns
- Current - Output High, Low:
- 5.2mA, 5.2mA
- Voltage - Supply:
- 2 V ~ 6 V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SSOP
74HC4538DB,118 FAQ
1.How can I place an order for 74HC4538DB,118 through Aetrix?
Please submit a Request for Quotation (RFQ) for 74HC4538DB,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 74HC4538DB,118 reliable?
The price and inventory of 74HC4538DB,118 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74HC4538DB,118 is usually 5 days.
3.What payment methods are accepted for 74HC4538DB,118?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74HC4538DB,118 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74HC4538DB,118?
74HC4538DB,118 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74HC4538DB,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 74HC4538DB,118?
For technical support, including 74HC4538DB,118 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74HC4538DB,118 requirements.
6.How does Aetrix verify that 74HC4538DB,118 is sourced from the original manufacturer or authorized distributors?
All 74HC4538DB,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 74HC4538DB,118 meets industry standards.
7.What is the process for return or replacement of 74HC4538DB,118?
All 74HC4538DB,118 units undergo pre-shipment inspection (PSI). If there is an issue with 74HC4538DB,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 74HC4538DB,118 part is unused and in its original packaging.
Return procedure for 74HC4538DB,118:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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