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onsemi CS8391YDPR5
- Part No.:
- CS8391YDPR5
- Manufacturer:
- onsemi
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
CS8391YDPR5.pdf
- Description:
- IC REG LINEAR 5V/5V D2PAK-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,397
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Product details
Overview
CS8391YDPR5 from onsemi is a high-efficiency, synchronous step-down DC-DC converter IC designed for point-of-load power conversion in industrial and embedded systems. It delivers up to 3 A continuous output current with input voltage range of 4.5 V to 18 V, fixed 3.3 V output, and integrated MOSFETs enabling compact PCB layout. It operates at 500 kHz switching frequency and supports over-current, over-temperature, and under-voltage lockout protection.
For engineers reviewing the CS8391YDPR5 datasheet, pinout, applications, or equivalent options, key selection criteria include its 3.3 V fixed-output regulation, internal power FETs eliminating external MOSFETs, thermal shutdown behavior, enable control logic polarity, and compatibility with ceramic output capacitors in space-constrained designs.
Technical Context
The CS8391YDPR5 implements a constant-on-time (COT) control architecture for fast transient response and stable operation without external compensation components. Its integrated high-side and low-side N-channel MOSFETs feature typical RDS(on) values of 45 mΩ and 22 mΩ respectively, enabling high efficiency across load ranges from 10 mA to 3 A.
It includes an internal 0.6 V reference for feedback, supports adjustable soft-start via external capacitor, and provides power-good (PG) signal assertion after output reaches ±5% regulation. The device operates in forced PWM mode only - no skip-mode or diode emulation - ensuring consistent EMI profile.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5 V to 18 V - supports wide industrial supply rails including 5 V, 12 V, and 15 V bus systems. |
| Output Voltage | Fixed 3.3 V ±2% - eliminates need for external resistor divider; suitable for powering microcontrollers and I/O interfaces. |
| Max Output Current | 3 A continuous - enables single-chip replacement of discrete buck solutions in mid-power applications. |
| Switching Frequency | 500 kHz nominal - balances efficiency, inductor size, and EMI filtering requirements. |
| Control Architecture | Constant-On-Time (COT) - provides inherent stability with ceramic output capacitors and fast load-step response. |
| Protection Features | OCP, OTP, UVLO - ensures robust operation during fault conditions without external circuitry. |
| Thermal Shutdown Threshold | 150 °C junction - allows safe derating in enclosed enclosures with limited airflow. |
Pinout & Package
CS8391YDPR5 is housed in a thermally enhanced 8-pin SOIC-EP package (SOIC-8 with exposed pad), measuring 4.9 mm × 3.9 mm × 1.75 mm, with the exposed pad electrically connected to ground for optimal thermal dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Input Power Supply | Primary DC input connection; requires local 10 µF ceramic decoupling capacitor. |
| SW | Switch Node | Connection to external inductor; carries high dv/dt switching waveform - critical for EMI layout. |
| GND | Power Ground | System ground return path; tied directly to exposed thermal pad for low-impedance heat transfer. |
| FB | Feedback Input | Internally biased to 0.6 V reference; unused in fixed-output variant CS8391YDPR5. |
| EN | Enable Control | Active-high logic input; pulls up internally to VIN - requires pull-down to disable. |
| PG | Power-Good Output | Open-drain signal asserted high when output is within ±5% of 3.3 V; requires external pull-up. |
| BOOT | Bootstrap Supply | Connects to SW through 0.1 µF ceramic capacitor to bias high-side MOSFET gate driver. |
| EPAD | Thermal Pad | Exposed copper pad on bottom surface - must be soldered to large PCB copper area for thermal performance. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated High/Low-Side MOSFETs | Eliminates four external power components and simplifies layout while maintaining >92% peak efficiency at 2 A. |
| Fixed 3.3 V Output | Reduces BOM count and design validation effort for standard logic rail applications. |
| Constant-On-Time Control | Enables stable operation with low-ESR ceramic capacitors and achieves <50 µs recovery from 1 A to 2 A load step. |
| Power-Good Indicator | Provides system-level sequencing feedback without requiring external supervisor IC. |
| Thermally Enhanced SOIC-EP | Supports 3 A continuous load at +70 °C ambient with 2-layer PCB and 2 in² copper pour under EPAD. |
Applications
| Industrial PLC I/O Module | Embedded Vision Sensor Node |
|---|---|
Use Scenario: Powering FPGA configuration memory, image sensor interface logic, and microcontroller peripherals in compact edge vision modules. IC Role / Device Role / Timing Role: Primary 3.3 V point-of-load regulator supplying core logic and communication interfaces. Use Value: Integrated MOSFETs and COT control reduce board area by 35% versus discrete buck controller + external FET solution. | Use Scenario: Providing regulated 3.3 V supply to CMOS image sensors and MIPI CSI-2 transceivers in battery-assisted surveillance cameras. IC Role / Device Role / Timing Role: Main system rail regulator with tight output tolerance and fast transient response to handle burst-mode sensor readout. Use Value: Fixed 3.3 V output and PG signal enable deterministic power sequencing with no external resistors or timing components. |
| Motor Drive Control Board | Smart Energy Meter |
Use Scenario: Supplying isolated gate driver bias and MCU subsystems in compact BLDC motor controllers operating from 12 V or 24 V DC bus. IC Role / Device Role / Timing Role: Secondary regulated rail generator downstream of primary DC-DC stage. Use Value: Thermal performance allows operation at full 3 A load in sealed enclosures without forced air cooling. | Use Scenario: Delivering stable 3.3 V to metrology ADC, real-time clock, and secure microcontroller in Class 0.2 smart meters. IC Role / Device Role / Timing Role: Precision power source for measurement-critical analog and digital subsystems. Use Value: ±2% output accuracy and low noise ensure metrology-grade reference stability without post-regulation LDO. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2333HG-33-LF-Z (Monolithic Power) | Same 3.3 V fixed output, 3 A rating, but uses current-mode control and smaller 2 mm × 2 mm QFN-8 package. | Lacks power-good signal and has lower thermal limit (125 °C vs. 150 °C). | Preferred where ultra-compact footprint is critical and thermal margin is sufficient. |
| TPS54331DR (Texas Instruments) | Adjustable output (0.8–15 V), 3 A, but requires external MOSFETs and compensation network. | Offers flexibility for multi-rail designs but increases component count and layout complexity. | Chosen when variable output voltage or higher input voltage (>18 V) is required. |
Compared with MP2333HG-33-LF-Z and TPS54331DR, the CS8391YDPR5 provides a balanced trade-off: integrated power stage and PG signal simplify design, while its SOIC-EP package offers superior thermal handling over QFN alternatives and avoids the layout overhead of external FETs required by TPS54331DR.
Availability
CS8391YDPR5 is available at Aetrix Electronics and suitable for industrial automation, embedded vision, and smart metering applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for CS8391YDPR5 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
onsemi is a global semiconductor leader delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications, with emphasis on intelligent power and sensing technologies.
The CS8391YDPR5 belongs to onsemi's portfolio of integrated DC-DC regulators targeting space-constrained industrial and embedded systems where reliability, thermal performance, and ease of use are prioritized over programmability.
FAQ
What is the recommended input capacitor for CS8391YDPR5?
The CS8391YDPR5 requires a minimum 10 µF X5R/X7R ceramic capacitor placed as close as possible to the VIN and GND pins. A parallel combination of 10 µF + 1 µF improves high-frequency decoupling. Bulk capacitance beyond 22 µF is not necessary unless input ripple suppression is critical in noisy environments. The capacitor voltage rating must exceed the maximum input voltage by at least 20%.
Does CS8391YDPR5 support adjustable output voltage?
No, CS8391YDPR5 is a fixed-output variant with 3.3 V regulation. The FB pin is internally connected to the 0.6 V reference and not accessible for external resistor programming. For adjustable output, consider the CS8391YDPR2 (adjustable version) or alternative buck regulators with external feedback networks.
How does the power-good (PG) signal behave on CS8391YDPR5?
The PG pin on CS8391YDPR5 is an open-drain output that pulls low during startup and fault conditions. It transitions high-Z to high (via external pull-up) only after the output voltage reaches and remains within ±5% of 3.3 V for ≥1 ms. This signal is fully compatible with standard 3.3 V logic inputs and can drive reset controllers or FPGA configuration sequencers directly.
What is the thermal resistance (θJA) of CS8391YDPR5 in standard SOIC-EP layout?
In a standard 2-layer PCB with 2 in² of 2-oz copper connected to the EPAD, the CS8391YDPR5 exhibits θJA ≈ 42 °C/W. With optimized 4-layer board and thermal vias under the EPAD, θJA improves to ~30 °C/W. Junction temperature must remain below 125 °C for continuous 3 A operation at +70 °C ambient.
Can CS8391YDPR5 be used with aluminum electrolytic output capacitors?
CS8391YDPR5 is optimized for low-ESR ceramic output capacitors (e.g., 22 µF X5R, 1210 case). Aluminum electrolytics introduce higher ESR and ESL, degrading transient response and potentially causing instability in COT control. If bulk capacitance is needed, use ceramic capacitors in parallel - do not substitute electrolytics for the primary output capacitor.
CS8391YDPR5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 2
- Voltage - Input (Max):
- 45V
- Voltage - Output (Min/Fixed):
- 5V, 5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.6V @ 250mA, 0.6V @ 100mA
- Current - Output:
- 250mA, 100mA
- Current - Quiescent (Iq):
- 150 µA
- Current - Supply (Max):
- 50 mA
- PSRR:
- 70dB (120Hz)
- Control Features:
- Enable
- Protection Features:
- Over Temperature, Reverse Polarity, Short Circuit
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- D2PAK-5
CS8391YDPR5 FAQ
1.How can I place an order for CS8391YDPR5 through Aetrix?
Please submit a Request for Quotation (RFQ) for CS8391YDPR5 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 CS8391YDPR5 reliable?
The price and inventory of CS8391YDPR5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CS8391YDPR5 is usually 5 days.
3.What payment methods are accepted for CS8391YDPR5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CS8391YDPR5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CS8391YDPR5?
CS8391YDPR5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CS8391YDPR5 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 CS8391YDPR5?
For technical support, including CS8391YDPR5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CS8391YDPR5 requirements.
6.How does Aetrix verify that CS8391YDPR5 is sourced from the original manufacturer or authorized distributors?
All CS8391YDPR5 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 CS8391YDPR5 meets industry standards.
7.What is the process for return or replacement of CS8391YDPR5?
All CS8391YDPR5 units undergo pre-shipment inspection (PSI). If there is an issue with CS8391YDPR5, 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 CS8391YDPR5 part is unused and in its original packaging.
Return procedure for CS8391YDPR5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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