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Texas Instruments SN74LV221ANSR
- Part No.:
- SN74LV221ANSR
- Manufacturer:
- Texas Instruments
- Category:
- Multivibrators
- Package:
- 16-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
SN74LV221ANSR.pdf
- Description:
- IC MULTIVIBRATOR 13.2NS 16SO
- Quantity:
- Payment:
- Shipping:
Inventory:4,398
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Product details
Overview
SN74LV221ANSR from Texas Instruments is a dual monostable multivibrator IC with Schmitt-trigger inputs, designed for precise pulse generation in 2V–5.5V systems. It features independent A (falling-edge) and B (rising-edge) trigger inputs per channel, overriding clear functionality, programmable output pulse duration via external R/C networks, and glitch-free power-up reset. It is used in timing control, debouncing, and delay generation circuits within industrial logic interfaces and instrumentation.
For engineers reviewing the SN74LV221ANSR datasheet, SN74LV221ANSR pinout, SN74LV221ANSR application, or SN74LV221ANSR equivalent, key selection considerations include its 16-pin SOP (NS) package, 11ns max propagation delay at 5V, Schmitt-trigger input hysteresis for noise immunity, Ioff support for partial-power-down operation, and compatibility with mixed-voltage signal environments.
Technical Context
The SN74LV221ANSR implements two independent edge-triggered monostable multivibrators, each with dual trigger inputs (A and B) and an overriding clear (CLR). Pulse width is externally set by resistor-capacitor networks connected to dedicated pins (Rext/Cext and Cext), enabling adjustable durations from nanoseconds to milliseconds. Triggering is deterministic due to Schmitt-trigger circuitry on all A, B, and CLR inputs, ensuring reliable operation even with slow or noisy transitions.
Each channel supports three distinct triggering modes: falling edge on A (with B high), rising edge on B (with A low), or rising edge on CLR (with A low and B high). Output states are latched and unaffected by subsequent A/B transitions once triggered; pulse termination can be forced early by asserting CLR low. Power-up behavior guarantees Q outputs start low and Q outputs high without external reset.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2V to 5.5V - Enables direct interfacing with 2.5V, 3.3V, and 5V logic families without level shifters. |
| Max tpd | 11ns at VCC = 5V - Supports high-speed timing applications requiring sub-12ns response latency. |
| Output Pulse Range | ~200ns to >1ms - Programmable via external R/C; e.g., 2kΩ/28pF yields ~200ns, 10kΩ/0.1µF yields ~1ms. |
| Ioff Support | Yes - Prevents backflow current during partial power-down, critical for hot-swap and power-gated subsystems. |
| Input Hysteresis | Schmitt-trigger on A, B, CLR - Rejects noise and ensures clean, jitter-free triggering from slow-rising signals. |
| Operating Temp | −40°C to +85°C - Qualified for industrial ambient conditions without derating. |
| ESD Rating | HBM ±2000V - Meets standard robustness requirements for handling and board assembly. |
Pinout & Package
The SN74LV221ANSR is housed in a 16-pin SOP (NS) package measuring 10.2mm × 7.8mm (body: 10.3mm × 5.30mm), compliant with JEDEC MS-012.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 A | Falling-edge trigger input (Ch1) | Active-low transition initiates output pulse when 1B = H; held low for alternate trigger methods. |
| 2 1B | Rising-edge trigger input (Ch1) | Active-high transition initiates output pulse when 1A = L; held high for alternate methods. |
| 3 1CLR | Overriding clear input (Ch1) | Rising edge resets output mid-pulse; driving low during active pulse terminates it immediately. |
| 4 1Q | Inverted output (Ch1) | Complementary to 1Q; low during active pulse, high otherwise. |
| 5 2Q | Non-inverted output (Ch2) | High during active pulse, low otherwise; matches standard monostable polarity convention. |
| 6 2Cext | Capacitor negative terminal (Ch2) | Connects to ground side of external timing capacitor; forms RC network with 7. |
| 7 2Rext/Cext | RC junction node (Ch2) | Connects external resistor to VCC and capacitor to 6; sets pulse width with 6. |
| 8 GND | Ground reference | Primary return path for all internal logic and timing currents; must be low-impedance. |
| 9 2A | Falling-edge trigger input (Ch2) | Functionally identical to Pin 1, but for Channel 2. |
| 10 2B | Rising-edge trigger input (Ch2) | Functionally identical to Pin 2, but for Channel 2. |
| 11 2CLR | Overriding clear input (Ch2) | Functionally identical to Pin 3, but for Channel 2. |
| 12 2Q | Inverted output (Ch2) | Complementary to 5; low during active pulse, high otherwise. |
| 13 1Q | Non-inverted output (Ch1) | High during active pulse, low otherwise; primary output for Channel 1. |
| 14 1Cext | Capacitor negative terminal (Ch1) | Ground-side connection for Channel 1 timing capacitor; pairs with 15. |
| 15 1Rext/Cext | RC junction node (Ch1) | Connects external resistor to VCC and capacitor to 14; sets Channel 1 pulse width. |
| 16 VCC | Power supply | Supplies core logic and output drivers; requires local 0.1µF bypass capacitor per TI layout guidelines. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent monostables | Enables two separate, non-interacting timing functions on one IC-reducing component count vs discrete solutions. |
| Programmable pulse width | External R/C network allows precise, wide-range adjustment (ns to ms) without firmware or digital control overhead. |
| Overriding clear | Hardware-level pulse termination via CLR pin provides deterministic, sub-10ns abort capability for safety-critical timing. |
| Glitch-free power-up reset | Guarantees known initial state (1Q/2Q = low, 1Q/2Q = high) without external POR circuitry or software initialization. |
| Mixed-mode voltage operation | Accepts input signals across full 0–5.5V range while powered at 2–5.5V-simplifies interface with legacy or heterogeneous logic rails. |
Applications
| Industrial Sensor Debouncing | Logic-Level Timing Delay |
|---|---|
Use Scenario: Mechanical switch or encoder outputs generate contact bounce or jitter that corrupts downstream counting or state detection. IC Role / Device Role / Timing Role: SN74LV221ANSR acts as a hardware-based debounce filter, generating clean, fixed-duration pulses after each valid edge. Use Value: Eliminates need for microcontroller polling or software debouncing algorithms; achieves <1µs jitter rejection via Schmitt-trigger inputs and deterministic monostable timing. | Use Scenario: A microcontroller GPIO requires a precise, repeatable delay before asserting a control signal to a peripheral (e.g., ADC sampling strobe). IC Role / Device Role / Timing Role: SN74LV221ANSR serves as a programmable one-shot timer, triggered by MCU output to generate a calibrated delay window. Use Value: Provides sub-10ns timing accuracy over temperature and voltage-superior to RC+comparator approaches-and avoids MCU resource consumption or interrupt latency. |
| Power Sequencing Control | Test Equipment Pulse Generation |
Use Scenario: Multiple power rails (e.g., core, I/O, analog) must power up/down in strict sequence with defined hold times to prevent latch-up or inrush damage. IC Role / Device Role / Timing Role: SN74LV221ANSR generates staggered enable pulses using cascaded triggers and external R/C timing. Use Value: Delivers deterministic, repeatable delays independent of MCU clock stability or firmware execution; supports fail-safe sequencing via overriding clear for emergency shutdown. | Use Scenario: Automated test equipment requires calibrated, repeatable stimulus pulses (e.g., for device under test clock enable or reset assertion). IC Role / Device Role / Timing Role: SN74LV221ANSR functions as a precision pulse generator, triggered by pattern generator outputs to produce accurate, variable-width stimuli. Use Value: Achieves ±1% pulse width consistency across units and temperature-critical for parametric test repeatability-and supports fast reconfiguration via external R/C swaps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar monostable multivibrator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AHC123AD | Higher VCC max (5.5V same), but slower max tpd (13.5ns @ 5V); no Ioff; no Schmitt inputs on CLR. | Less robust against slow/noisy inputs; unsuitable for partial-power-down systems. | Choose if cost sensitivity outweighs noise immunity and power-down safety requirements. |
| SN74LVC1G123DBVR | Single-channel, SOT-23-6 package; lower drive strength (±24mA); identical VCC range and Schmitt inputs. | Requires two devices for dual-channel function; smaller footprint but higher board area cost for dual use. | Choose for space-constrained single-timing applications where dual-channel integration is unnecessary. |
Compared with SN74AHC123AD and SN74LVC1G123DBVR, the SN74LV221ANSR uniquely combines dual-channel integration, Schmitt-trigger inputs on all controls, Ioff-enabled safe power-down, and 11ns speed-making it optimal for industrial timing where reliability, density, and mixed-voltage interoperability are prioritized.
Availability
SN74LV221ANSR is available at Aetrix Electronics and suitable for industrial sensor interfaces, power sequencing controllers, test equipment timing modules, and logic-level debounce circuits requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SN74LV221ANSR 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic ICs, with decades of expertise in high-reliability timing and interface solutions.
The SN74LV221ANSR belongs to TI's LV family of low-voltage logic devices, engineered for robust operation across 2V–5.5V rails in industrial automation, instrumentation, and communications infrastructure where noise immunity and power flexibility are essential.
FAQ
What is the maximum output pulse duration achievable with SN74LV221ANSR?
The SN74LV221ANSR supports output pulse durations from approximately 200ns up to several milliseconds, depending on external R/C values. With a 10kΩ resistor and 0.1µF capacitor, the SN74LV221ANSR delivers ~1ms pulses; larger capacitances (e.g., 1µF) extend duration further. The device does not impose upper limits on Cext, though practical constraints like leakage and power-down discharge must be considered per Section 7.1.2 of the datasheet.
Does SN74LV221ANSR support true dual-edge triggering per channel?
Yes. Each channel of the SN74LV221ANSR supports both falling-edge (via A input) and rising-edge (via B input) triggering, provided the complementary input is held at the correct logic level (A low for B-trigger, B high for A-trigger). This dual-edge capability enables flexible synchronization with diverse signal sources without external inverters.
Can SN74LV221ANSR operate with different supply and input voltage levels simultaneously?
Yes. The SN74LV221ANSR supports mixed-mode voltage operation: inputs tolerate 0–5.5V regardless of VCC (2–5.5V), allowing direct interfacing with 5V sensors or microcontrollers while powered from a 3.3V rail. This eliminates level-shifter components in heterogeneous logic systems.
How does the overriding clear function behave during an active output pulse?
Asserting the CLR input low during an active output pulse on either channel immediately forces the corresponding Q and Q outputs to their reset states (Q = low, Q = high), terminating the pulse prematurely. This hardware-level abort is asynchronous and deterministic, with propagation delay specified in the switching characteristics tables (e.g., 6.5ns max at 5V).
Is SN74LV221ANSR pin-compatible with older TTL or CMOS monostables?
The SN74LV221ANSR shares identical pin assignments with the 'AHC123A and 'AHCT123A devices, enabling drop-in replacement in designs not utilizing the retrigger feature. However, it is not pin-compatible with standard 74LS123 or 74HC123 due to differences in pin function mapping (e.g., dedicated Cext/Rext/Cext pins versus shared timing nodes).
SN74LV221ANSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74LV
- Package/Case:
- 16-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Logic Type:
- Monostable
- Independent Circuits:
- 2
- Schmitt Trigger Input:
- Yes
- Propagation Delay:
- 13.2 ns
- Current - Output High, Low:
- 12mA, 12mA
- Voltage - Supply:
- 2 V ~ 5.5 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SO
SN74LV221ANSR FAQ
1.How can I place an order for SN74LV221ANSR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74LV221ANSR 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 SN74LV221ANSR reliable?
The price and inventory of SN74LV221ANSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74LV221ANSR is usually 5 days.
3.What payment methods are accepted for SN74LV221ANSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74LV221ANSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74LV221ANSR?
SN74LV221ANSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74LV221ANSR 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 SN74LV221ANSR?
For technical support, including SN74LV221ANSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74LV221ANSR requirements.
6.How does Aetrix verify that SN74LV221ANSR is sourced from the original manufacturer or authorized distributors?
All SN74LV221ANSR 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 SN74LV221ANSR meets industry standards.
7.What is the process for return or replacement of SN74LV221ANSR?
All SN74LV221ANSR units undergo pre-shipment inspection (PSI). If there is an issue with SN74LV221ANSR, 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 SN74LV221ANSR part is unused and in its original packaging.
Return procedure for SN74LV221ANSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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