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Nexperia USA Inc. HEF4538BT,652
- Part No.:
- HEF4538BT,652
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Multivibrators
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
HEF4538BT,652.pdf
- Description:
- IC MULTIVIBRATOR 40NS 16SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,947
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Product details
Overview
HEF4538BT,652 from Nexperia is a dual retriggerable-resettable monostable multivibrator in SO16 package, delivering precision timing with ±0.2 % pulse width variation over -40 °C to +125 °C. Each channel features independent active-LOW reset (nCD), dual-edge trigger inputs (nA/nB), complementary outputs (nQ/nQ), and external REXT×CEXT timing control enabling 10 μs to infinite pulse widths. It operates across 3 V–15 V supply and supports industrial motor control timing and digital signal edge detection.
For engineers reviewing the HEF4538BT,652 datasheet, HEF4538BT,652 pinout, HEF4538BT,652 application, or HEF4538BT,652 equivalent, key selection criteria include retriggerable monostable behavior, Schmitt-triggered inputs for noise immunity, LOCMOS-based pulse accuracy, and dual-channel independence in a single SO16 footprint.
Technical Context
The HEF4538BT,652 implements two independent monostable circuits using LOCMOS linear design techniques to guarantee precise REXT×CEXT-based output pulse width (tW) with ±0.2 % variation over temperature. Each channel accepts both positive- and negative-edge triggers via separate nA (HIGH-to-LOW) and nB (LOW-to-HIGH) inputs, with immediate termination on nCD assertion.
Schmitt-trigger input thresholds provide robustness against slow-rising/falling signals, while static operation and CMOS low-power dissipation support battery-powered and thermally constrained designs. The device maintains symmetrical output drive (±2.4 mA at 15 V) and full functionality across its -40 °C to +125 °C operating range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 3 V to 15 V - Enables direct interface with 5 V, 10 V, and 15 V logic systems without level-shifting. |
| Pulse Width Accuracy | ±0.2 % over -40 °C to +125 °C - Ensures stable timing in automotive under-hood and industrial control environments. |
| Output Pulse Range | 10 μs to ∞ - Achieved via external REXT and CEXT; tW = REXT × CEXT enables flexible timing from microseconds to seconds. |
| Propagation Delay | 32 ns to 440 ns (VDD = 15 V to 5 V) - Low-latency response critical for real-time edge detection and pulse shaping. |
| Input Threshold Type | Schmitt-trigger - Tolerates slow input edges up to 0.08 μs/V at 15 V, eliminating need for external conditioning. |
| Reset Response Time | 5 ns min recovery time (trec) - Guarantees sub-10 ns pulse termination for safety-critical interrupt masking. |
| ESD Protection | HBM > 2000 V, CDM > 1000 V - Robust handling during PCB assembly and field service without additional protection circuitry. |
Pinout & Package
HEF4538BT,652 uses the SOT109-1 (SO16) plastic small outline package: 16-pin, 3.9 mm body width, 1.27 mm lead pitch, surface-mount compatible with standard reflow profiles.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 15 (1CEXT, 2CEXT) | External capacitor ground connection | Must be tied to VSS; provides reference node for timing capacitor CEXT in each monostable channel. |
| 2, 14 (1REXT/CEXT, 2REXT/CEXT) | Timing resistor/capacitor node | Connects external REXT and CEXT; defines tW = REXT × CEXT; high-impedance input minimizes loading error. |
| 3, 13 (1CD, 2CD) | Active-LOW direct reset | Asynchronous termination of ongoing output pulse; overrides all trigger inputs with <10 ns latency. |
| 4, 12 (1B, 2B) | LOW-to-HIGH trigger input | Rising-edge sensitive; Schmitt-triggered for noise immunity; no minimum pulse width required at 15 V. |
| 5, 11 (1A, 2A) | HIGH-to-LOW trigger input | Falling-edge sensitive; independent of nB; allows dual-edge triggering per channel without external logic. |
| 6, 10 (1Q, 2Q) | True output | Active-HIGH pulse output; drives loads up to ±2.4 mA at 15 V; TTL/CMOS compatible voltage levels. |
| 7, 9 (1Q, 2Q) | Complementary output | Active-LOW inverted pulse; enables direct interface with enable/disable inputs requiring active-low assertion. |
| 8 (VSS) | Ground supply | Reference for all inputs, outputs, and timing components; must be low-inductance connection for timing stability. |
| 16 (VDD) | Positive supply | Power rail for entire IC; decoupling capacitor (100 nF) recommended within 5 mm of pin for noise suppression. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent monostables | Enables synchronized yet isolated timing functions-e.g., one channel for pulse stretching, another for delay generation-without cross-talk. |
| Retriggerable & resettable operation | Allows dynamic pulse extension during active output (retrigger) and forced early termination (nCD), essential for fault-responsive systems. |
| LOCMOS precision timing | Guarantees ±0.2 % tW stability over full temperature and supply range-superior to standard CMOS monostables lacking linear process tuning. |
| Schmitt-trigger inputs | Eliminates need for external RC filters or comparators when interfacing with noisy sensors, mechanical switches, or slow microcontroller GPIOs. |
| Wide 3 V–15 V operation | Supports direct integration into mixed-voltage systems (e.g., 3.3 V MCU controlling 12 V solenoid drivers) without external regulators or level shifters. |
Applications
| Industrial Motor Control | Digital Signal Edge Detection |
|---|---|
|
Use Scenario: Generating precise enable pulses for IGBT gate drivers in variable-frequency drives, where timing jitter directly impacts torque ripple. IC Role / Device Role / Timing Role: Dual-channel monostable provides synchronized dead-time insertion and fault-triggered shutdown pulses. Use Value: ±0.2 % pulse width stability ensures consistent switching margins across ambient temperatures from -40 °C to +125 °C. |
Use Scenario: Converting irregular mechanical switch bounce into clean, debounced logic pulses for PLC input modules. IC Role / Device Role / Timing Role: Monostable acts as hardware debouncer with adjustable pulse width set by REXT/CEXT. Use Value: Schmitt-trigger inputs tolerate slow rise times (<10 μs), eliminating external RC networks and reducing BOM count. |
| Power Supply Sequencing | Test Equipment Pulse Generation |
|
Use Scenario: Controlling power-up order of multi-rail FPGA systems where core voltage must stabilize before I/O banks are enabled. IC Role / Device Role / Timing Role: One monostable generates fixed-delay enable signal; second provides reset hold-off after power-on. Use Value: Retriggerable behavior allows dynamic extension of sequencing delay if upstream rail monitoring detects instability. |
Use Scenario: Providing calibrated test pulses to validate oscilloscope trigger sensitivity and jitter measurement accuracy. IC Role / Device Role / Timing Role: Precision monostable serves as traceable timing reference with known tW = REXT × CEXT. Use Value: Output pulse width variation ≤±0.2 % meets calibration-grade requirements for metrology-grade test fixtures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar monostable multivibrator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74HC4538D,653 | Same pinout and function but HCMOS (not LOCMOS); ±1.5 % tW variation over VDD, ±1 % over temperature. | Lacks LOCMOS precision; suitable for non-critical timing where cost is prioritized over accuracy. | Select when ±1 % pulse width tolerance is acceptable and supply voltage is stable near 5 V. |
| CD4098BE | Single monostable, DIP-16 package; ±5 % tW accuracy; max 10 V supply; no Schmitt inputs. | Requires external hysteresis for noise immunity; limited to lower voltage rails and discrete-channel implementations. | Choose only for legacy through-hole designs with relaxed timing specs and no retrigger/reset requirements. |
Compared with 74HC4538D,653 and CD4098BE, the HEF4538BT,652 delivers superior pulse width stability (±0.2 % vs. ±1.5 % or ±5 %), dual-channel integration in SO16, and Schmitt-triggered inputs-making it the only option for high-reliability industrial timing where parameter drift must be minimized.
Availability
HEF4538BT,652 is available at Aetrix Electronics and suitable for industrial motor control, power supply sequencing, digital signal edge detection, and test equipment pulse generation requiring stable component supply across extended temperature ranges.
Supply support for HEF4538BT,652 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 specializing in high-performance, energy-efficient logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.
The HEF4538B belongs to Nexperia's precision timing logic family, designed specifically for applications demanding accurate, retriggerable monostable behavior in harsh thermal and electrical environments.
FAQ
What is the minimum external timing capacitor value supported?
The datasheet specifies CEXT ≥ 2000 pF for guaranteed accuracy. Below this value, leakage currents dominate timing error; typical designs use 2.2 nF to 10 μF. At 2000 pF and 100 kΩ REXT, tW = 200 μs with ±0.2 % stability over temperature.
Can both monostables be triggered simultaneously without interference?
Yes-each channel is fully independent. Pin 1A/1B/1CD/1Q/1Q operate separately from 2A/2B/2CD/2Q/2Q. No shared internal nodes exist; crosstalk is limited to substrate coupling, which is suppressed by LOCMOS isolation and proper PCB grounding.
Is the HEF4538BT,652 qualified for automotive applications?
No. The HEF4538BT,652 is rated for -40 °C to +125 °C but is not AEC-Q100 qualified. Nexperia explicitly states in Section 14 that non-automotive qualified products are unsuitable for safety-critical automotive use without additional validation by the customer.
How does the retrigger function behave during an active output pulse?
A new trigger on nA or nB during an active output extends tW by REXT×CEXT from the retrigger edge-not from the original start. This "pulse lengthening" behavior is confirmed in Fig. 3(2) and Table 3, enabling adaptive timing in response to recurring events.
HEF4538BT,652 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- 4000B
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Logic Type:
- Monostable
- Independent Circuits:
- 2
- Schmitt Trigger Input:
- No
- Propagation Delay:
- 40 ns
- Current - Output High, Low:
- 3.4mA, 3.4mA
- Voltage - Supply:
- 3 V ~ 15 V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SO
HEF4538BT,652 FAQ
1.How can I place an order for HEF4538BT,652 through Aetrix?
Please submit a Request for Quotation (RFQ) for HEF4538BT,652 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 HEF4538BT,652 reliable?
The price and inventory of HEF4538BT,652 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for HEF4538BT,652 is usually 5 days.
3.What payment methods are accepted for HEF4538BT,652?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for HEF4538BT,652 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for HEF4538BT,652?
HEF4538BT,652 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your HEF4538BT,652 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 HEF4538BT,652?
For technical support, including HEF4538BT,652 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your HEF4538BT,652 requirements.
6.How does Aetrix verify that HEF4538BT,652 is sourced from the original manufacturer or authorized distributors?
All HEF4538BT,652 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 HEF4538BT,652 meets industry standards.
7.What is the process for return or replacement of HEF4538BT,652?
All HEF4538BT,652 units undergo pre-shipment inspection (PSI). If there is an issue with HEF4538BT,652, 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 HEF4538BT,652 part is unused and in its original packaging.
Return procedure for HEF4538BT,652:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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