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onsemi CS8121YTVA5
- Part No.:
- CS8121YTVA5
- Manufacturer:
- onsemi
- Package:
- -
- Datasheet:
-
CS8121YTVA5.pdf
- Description:
- IC REG LINEAR FIXED LDO REG
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Inventory:2,550
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Product details
Overview
CS8121YTVA5 from ON Semiconductor is a 5V ±4%, 1A precision linear regulator in a 5-lead TO-220 vertical package, featuring integrated ENABLE and RESET functions, 1.2V dropout at full load, 4mA quiescent current, and 60V peak transient voltage tolerance-designed for automotive power rail conditioning and microprocessor supply control.
For engineers reviewing the CS8121YTVA5 datasheet, pinout, applications, or equivalent options, key selection considerations include its composite NPN-PNP output stage, sleep-mode IQ of 250µA, RESET validity down to VOUT = 1V, and thermal shutdown at 150°C junction temperature.
Technical Context
The CS8121YTVA5 uses a composite NPN-PNP pass transistor architecture to achieve low dropout (1.2V @ 1A) while limiting quiescent current draw to 4mA under full load. Its internal bandgap reference switches from VIN to VOUT after regulation is established, improving PSRR by >70dB at 120Hz.
ENABLE is a CMOS-compatible input that disables the output stage and forces the IC into 250µA sleep mode when driven above 2.9V; RESET is an open-collector NPN output asserting low when VOUT falls below 4.75V (typ) or during power-up, with hysteresis and operation valid down to VOUT = 1V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 5.0V ±4% - maintains stable 5V supply across -40°C to +125°C ambient and 7–26V input range. |
| Max Output Current | 1A continuous - internally current-limited; supports automotive ECUs and industrial controllers requiring robust local regulation. |
| Dropout Voltage | 1.2V @ 1A - enables operation with minimal headroom, e.g., 6.2V input sustaining 5V/1A output in battery-sourced systems. |
| Quiescent Current | 4mA @ IOUT = 1A - minimizes no-load power loss; drops to 250µA in ENABLE-disabled sleep mode. |
| PSRR | 70dB @ 120Hz - suppresses ripple from alternator or switching pre-regulators in automotive environments. |
| Transient Tolerance | 60V peak - survives ISO 7637-2 Load Dump pulses without external clamping. |
| RESET Threshold | VOUT < 4.75V (decreasing) - provides reliable brown-out detection with 40mV hysteresis and operation down to VOUT = 1V. |
Pinout & Package
CS8121YTVA5 is housed in a 5-lead TO-220 vertical package (TVA variant), with exposed tab electrically connected to VIN for thermal conduction and mechanical mounting. The package has RΘJC = 2.5°C/W and RΘJA ≈ 50°C/W on standard FR-4 PCB with 1-in² copper pour.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | VIN | Main input supply connection; also ties to exposed tab for thermal path and must be isolated from ground plane if chassis-ground referenced. |
| 2 | ENABLE | CMOS-compatible active-high enable; >2.9V disables output and enters 250µA sleep mode; hysteresis improves noise immunity. |
| 3 | GND | Analog and power ground reference; requires low-impedance connection to minimize RESET and regulation error. |
| 4 | RESET | Open-collector NPN output; pulls low during power-up or when VOUT drops out of regulation; requires external pull-up to VOUT or system rail. |
| 5 | VOUT | Regulated 5V output; supplies microprocessor core logic, sensors, or interface ICs; requires ≥10µF tantalum output capacitor for stability. |
Key Features
| Feature | Design Value |
|---|---|
| Composite NPN-PNP Pass Transistor | Enables 1.2V dropout at 1A while avoiding deep saturation-reducing power dissipation and improving efficiency over standard PNP-only LDOs. |
| Supply-Referenced Bandgap Switching | Switches internal reference from VIN to VOUT once regulation is achieved-boosting PSRR by >16dB at 120Hz versus fixed-reference designs. |
| RESET Valid Down to 1V | Guarantees reset assertion even during severe brown-out or partial failure-critical for fail-safe microcontroller boot sequencing. |
| 60V Peak Transient Tolerance | Withstands automotive load dump events per ISO 7637-2 without external TVS-reducing BOM count and board space in vehicle ECU designs. |
| Thermal Shutdown with Hysteresis | Turns off output at 150°C junction temperature and re-enables only after cooling to ~120°C-prevents thermal cycling damage during overload conditions. |
Applications
| Automotive Engine Control Unit (ECU) | Industrial PLC I/O Module Power |
|---|---|
Use Scenario: Regulating 5V supply for MCU, CAN transceiver, and analog sensor interfaces in under-hood engine management systems exposed to 12V battery transients and -40°C to +125°C ambient. IC Role / Device Role / Timing Role: Primary 5V linear regulator with ENABLE-controlled power gating and RESET-driven MCU initialization sequencing. Use Value: 60V transient tolerance eliminates need for external TVS; RESET validity to 1V ensures deterministic boot after cold-crank voltage sag. | Use Scenario: Providing clean, sequenced 5V power to isolated digital I/O channels and fieldbus interface ICs in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Local point-of-load regulator with microprocessor-controlled ENABLE and fault-signaling RESET for diagnostics and safe shutdown. Use Value: Sleep-mode IQ of 250µA reduces standby power in always-on modules; 1.2V dropout allows operation from 6.2V backup rails during AC mains loss. |
| Telematics Control Unit (TCU) | Railway Signaling Interface Board |
Use Scenario: Powering GPS baseband processor, cellular modem, and secure element in vehicle telematics units subject to ignition cycling and battery voltage fluctuations. IC Role / Device Role / Timing Role: System supervisor regulator enabling controlled power-up/down via µP I/O port and providing reset signaling during brown-out. Use Value: ENABLE hysteresis prevents false disable during noisy ignition transitions; RESET delay programmability supports multi-core boot timing requirements. | Use Scenario: Delivering regulated 5V to safety-critical relay drivers and opto-isolators in EN 5012x-compliant railway signaling hardware operating from 24V DC traction batteries. IC Role / Device Role / Timing Role: Fault-protected linear regulator with thermal shutdown and short-circuit limiting for SIL-2 functional safety subsystems. Use Value: Internal short-circuit current limit of 1.5A prevents catastrophic failure during relay coil short; thermal shutdown at 150°C meets EN 50129 thermal derating requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2940CT-5.0/NOPB | 5V fixed output, 1A, 0.5V dropout (typ), no ENABLE/RESET, 60V transient rating. | Lacks microprocessor control functions; requires external reset IC and enable circuitry for sequencing. | Choose when simplicity and cost outweigh need for integrated control features. |
| TLV1117-50IDCYR | 5V fixed output, 800mA, 1.2V dropout (typ), no ENABLE/RESET, max 20V input, no transient protection. | Lower current and input voltage rating; unsuitable for automotive load dump or 1A loads. | Consider only for non-automotive, low-power embedded applications with benign supply conditions. |
Compared with LM2940CT-5.0/NOPB and TLV1117-50IDCYR, the CS8121YTVA5 uniquely integrates ENABLE and RESET in a 1A, 60V-tolerant package-enabling single-chip power supervision where sequencing, fault signaling, and transient resilience are mandatory.
Availability
CS8121YTVA5 is available at Aetrix Electronics and suitable for automotive ECU design, industrial PLC power modules, and railway signaling interface boards requiring stable component supply and long-term lifecycle support.
Supply support for CS8121YTVA5 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
ON Semiconductor (now onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, and sensor solutions for automotive, industrial, and cloud infrastructure markets.
The CS8121YTVA5 belongs to ON Semiconductor's automotive-grade linear regulator family, engineered specifically for harsh-environment power conditioning in engine control, body electronics, and telematics systems.
FAQ
What is the maximum input voltage rating for the CS8121YTVA5?
The CS8121YTVA5 has an absolute maximum DC input voltage of 26V and can withstand 60V peak transient voltage per ISO 7637-2 load dump tests. Operation above 26V DC risks permanent damage, but the device remains functional during brief 60V spikes common in automotive battery systems. Always verify input filtering and layout practices to ensure reliability under real-world transients. The CS8121YTVA5 is designed for 12V and 24V nominal automotive systems.
Does the CS8121YTVA5 require an external output capacitor, and what type is recommended?
Yes, the CS8121YTVA5 requires an external output capacitor for stability, with a minimum value of 10µF tantalum as specified in the datasheet. Aluminum electrolytic capacitors may be used if ESR is ≥1Ω, but ceramic or film types with near-zero ESR risk oscillation due to loop instability. The capacitor must be placed close to the VOUT and GND pins, and its voltage rating should exceed the maximum expected input voltage. This requirement applies directly to all CS8121YTVA5 implementations.
How does the ENABLE function operate on the CS8121YTVA5?
The ENABLE pin on the CS8121YTVA5 is a CMOS-compatible active-high control input. When pulled above 2.9V (typ), it disables the output pass transistor, placing VOUT in high-impedance state and reducing quiescent current to 250µA in sleep mode. Release below 2.1V (typ) re-enables regulation. Built-in 800mV hysteresis prevents chatter during slow-rising signals. This behavior is fully characterized across temperature and is integral to the CS8121YTVA5's microprocessor supervision capability.
Can the CS8121YTVA5 be used in a 24V automotive system?
Yes, the CS8121YTVA5 supports input voltages up to 26V DC and tolerates 60V transients, making it suitable for 24V nominal automotive systems including commercial vehicles and off-road equipment. Its 1.2V dropout allows regulation down to 25.2V input at full 1A load. Thermal design must account for higher power dissipation-use the RΘJA = 50°C/W spec with adequate copper pour or heatsinking. All electrical parameters in the CS8121YTVA5 datasheet are validated across the full 7–26V input range.
What is the purpose of the RESET output on the CS8121YTVA5, and how is it used?
The RESET output on the CS8121YTVA5 is an open-collector NPN transistor that asserts low during power-up (when VOUT rises above VOUT − 100mV) or whenever VOUT drops below 4.75V (typ) during brown-out. It remains valid down to VOUT = 1V and requires an external pull-up resistor to VOUT or another stable rail. This signal synchronizes microcontroller reset sequencing and enables system-level fault detection. Its behavior is guaranteed across temperature and is a defining feature of the CS8121YTVA5.
CS8121YTVA5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Output Configuration:
- -
- Output Type:
- -
- Number of Regulators:
- -
- Voltage - Input (Max):
- -
- Voltage - Output (Min/Fixed):
- -
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- -
- Current - Output:
- -
- Current - Quiescent (Iq):
- -
- Current - Supply (Max):
- -
- PSRR:
- -
- Control Features:
- -
- Protection Features:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
CS8121YTVA5 FAQ
1.How can I place an order for CS8121YTVA5 through Aetrix?
Please submit a Request for Quotation (RFQ) for CS8121YTVA5 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 CS8121YTVA5 reliable?
The price and inventory of CS8121YTVA5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CS8121YTVA5 is usually 5 days.
3.What payment methods are accepted for CS8121YTVA5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CS8121YTVA5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CS8121YTVA5?
CS8121YTVA5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CS8121YTVA5 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 CS8121YTVA5?
For technical support, including CS8121YTVA5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CS8121YTVA5 requirements.
6.How does Aetrix verify that CS8121YTVA5 is sourced from the original manufacturer or authorized distributors?
All CS8121YTVA5 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 CS8121YTVA5 meets industry standards.
7.What is the process for return or replacement of CS8121YTVA5?
All CS8121YTVA5 units undergo pre-shipment inspection (PSI). If there is an issue with CS8121YTVA5, 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 CS8121YTVA5 part is unused and in its original packaging.
Return procedure for CS8121YTVA5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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