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Vishay Siliconix SIC478ED-T1-GE3
- Part No.:
- SIC478ED-T1-GE3
- Manufacturer:
- Vishay Siliconix
- Package:
- PowerPAK® MLP55-27
- Datasheet:
-
SIC478ED-T1-GE3.pdf
- Description:
- IC REG BCK ADJ POWERPAK MLP55-27
- Quantity:
- Payment:
- Shipping:
Inventory:440
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Product details
Overview
SIC478ED-T1-GE3 from Vishay Siliconix is a 5 A, 4.5 V to 55 V input synchronous buck DC/DC converter with integrated high-side and low-side MOSFETs, adjustable 0.8 V output, internal compensation, and 2 MHz max switching frequency - deployed in industrial power supplies, telecom rectification, and robotics motor control.
For engineers reviewing the SIC478ED-T1-GE3 datasheet, SIC478ED-T1-GE3 pinout, SIC478ED-T1-GE3 application, or SIC478ED-T1-GE3 equivalent, key selection considerations include valley current limit configuration (3 A / 4.2 A / 6 A), programmable soft start, power-good flag timing (15–35 μs), and MLP55-27L thermal performance (θJA = 12 °C/W).
Technical Context
The SIC478ED-T1-GE3 implements voltage-mode constant-on-time (COT) control with adaptive zero-current detection for DCM operation, enabling ultrafast transient response without external ESR networks. Its internal ramp generator and 0.8 V reference comparator drive fixed on-time pulses (45–100 ns min/max) with 250 ns minimum off-time.
It integrates dual N-channel MOSFETs optimized for 98 % peak efficiency at 24 VIN/12 VOUT, supports pre-bias startup and output voltage tracking, and uses VCIN biasing flexibility (4.5–55 V) to reduce LDO losses when driven from a lower auxiliary rail.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output current | 5 A continuous - matches SiC478 variant within pin-compatible family (SiC476/477/478/479) |
| Input voltage range | 4.5 V to 55 V - enables single-rail operation across 12 V, 24 V, and 48 V industrial/telecom systems |
| Feedback reference | 0.800 V ±0.8 mV (−40 °C to +125 °C) - ensures ≤±1 % output accuracy over full temp range |
| Switching frequency | 100 kHz to 2 MHz - set by resistor on fSW pin; supports high-density layout and EMI optimization |
| Valley OCP options | 3 A / 4.2 A / 6 A - selected via ILIMIT pin tied to AGND / floating / VDD respectively |
| Thermal shutdown | 150 °C trip with 35 °C hysteresis - prevents latch-up during sustained overload or poor heatsinking |
| Power good delay | 15–35 μs - provides clean sequencing signal for downstream logic or FPGA configuration |
Pinout & Package
Package: PowerPAK® MLP55-27L (5 mm × 5 mm, 27-pin lead-free QFN with exposed thermal pad).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VCIN | Bias supply input for VDD/VDRV LDOs | Accepts 4.5–55 V; decoupled with 0.1 μF to AGND; enables loss reduction when sourced below VIN |
| 2 PGOOD | Open-drain power-good indicator | Asserts high-Z when VFB within ±10 % of target; requires external 10 kΩ pull-up; 6–15 Ω on-resistance |
| 3 EN | Enable control with hysteresis | High-voltage compatible (0–55 V); 1.4 V threshold with 200 mV hysteresis; internal 6 MΩ pull-down |
| 4 BOOT | High-side gate driver bootstrap node | Connected via RC network to PHASE; ≥4.7 Ω resistor recommended to limit shoot-through risk |
| 5,6 PHASE | High-side FET source / low-side FET drain node | Switch-node return path; must be routed with minimal loop area to reduce EMI and ringing |
| 7–9,29 VIN | Main power stage input | Connects to high-side FET drain; requires local ceramic decoupling to PGND near pads |
| 10–11,17,30 PGND | Power ground | High-current return for MOSFETs and input caps; separate from AGND to avoid noise coupling |
| 12–14 SW | Switch node | Drives external inductor; high dv/dt node requiring tight layout and guard ring |
| 15 GL | Low-side gate driver output | Directly drives low-side FET gate; not user-accessible; internal only |
| 16 VDRV | Internal gate driver supply | 4.75–5.55 V output of internal LDO; decoupled with 4.7 μF to PGND |
| 19 SS | Soft-start timing capacitor node | Charged by 5 μA internal current source; sets ramp time per CSS = (tSS × 5 μA)/0.8 V |
| 20 VOUT | Output voltage sense point | Used for internal ripple injection; connects directly to output capacitor anode |
| 22 VFB | Feedback input | Compares against 0.8 V reference; connects to resistor divider from VOUT to AGND |
| 23,28 AGND | Analog ground | Reference for VFB, SS, fSW, MODE, ILIMIT; shorted together with wide trace under IC |
| 24 fSW | Frequency setting input | Resistor to AGND sets fSW; RfSW = (VOUT × 1.9×10−10)/fSW |
| 25 ILIMIT | Current limit selection | Tied to AGND → 3 A; floating → 4.2 A; tied to VDD → 6 A (valley OCP) |
| 26 VDD | Internal bias supply output | 5 V ±250 mV LDO output; decoupled with 1 μF to AGND; UVLO at 3.75–4.25 V |
| 27 MODE | Operating mode selection | Resistor to AGND selects PS mode enabled/disabled and VDRV regulator on/off (4 modes) |
Key Features
| Feature | Design Value |
|---|---|
| Internally compensated loop | Stable with any output capacitor type (ceramic, polymer, electrolytic) - eliminates need for ESR tuning networks |
| Programmable light-load efficiency | Diode emulation + frequency foldback in power-save mode reduces no-load current to 156 μA |
| Robust protection suite | OCP (pulse-by-pulse), OVP (120 % VOUT), UVP (20 % VOUT), OTP (150 °C), and UVLO on all rails |
| Pre-bias startup support | Prevents reverse current and output collapse when VOUT is pre-charged before enable |
| Adjustable soft start | Capacitor-programmed ramp avoids inrush current; configurable from 1 ms to >100 ms |
Applications
| Industrial Motor Drives | Telecom Base Station Power |
|---|---|
Use Scenario: Powering FPGA I/O banks and auxiliary logic in servo drive controllers operating from 24 V or 48 V DC bus. IC Role / Device Role / Timing Role: Primary 5 A buck regulator delivering stable 1.2 V or 1.8 V core voltage with <1 % regulation error across −40 °C to +105 °C ambient. Use Value: Internal compensation and ceramic-cap stability eliminate board space consumed by RC networks; 2 MHz capability allows <2.2 μH inductors. | Use Scenario: Intermediate 5 V rail generation in distributed power architecture for remote radio units (RRUs). IC Role / Device Role / Timing Role: High-efficiency point-of-load converter accepting wide-input 36–57 V telecom range and delivering tightly regulated 5 V @ 5 A. Use Value: 98 % peak efficiency minimizes thermal load in sealed enclosures; PGOOD enables safe FPGA boot sequencing. |
| Robotics Actuator Control | Industrial PLC I/O Modules |
Use Scenario: Supplying 3.3 V or 5 V to microcontroller, CAN transceiver, and sensor interface in mobile robot joint controllers. IC Role / Device Role / Timing Role: Compact, thermally robust buck converter handling 4.5–55 V input transients common in battery-powered or PoE-powered robotic platforms. Use Value: MLP55-27L package delivers 5 A in 25 mm² footprint; OTP hysteresis prevents thermal cycling during intermittent high-torque events. | Use Scenario: Generating isolated 3.3 V logic supply from 24 V field bus in modular I/O backplanes with strict EMC requirements. IC Role / Device Role / Timing Role: Low-noise, high-PWM-frequency buck regulator minimizing conducted emissions into adjacent analog signal paths. Use Value: Adjustable 100 kHz–2 MHz fSW enables EMI peak shifting; internal COT control ensures <10 μs transient recovery. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2451DT-LF-Z | 36 V max input, 0.8 A output, external MOSFETs required; no integrated power stage | Lower current, lower integration - suited for cost-sensitive sub-1 A designs where layout space permits discrete FETs | Select MP2451DT-LF-Z only if input <36 V and output ≤0.8 A; requires external gate drivers and loop compensation |
| TPS54560QDGQRQ1 | 60 V max input, 5 A output, but requires external bootstrap diode and has higher quiescent current (146 μA vs. 156 μA) | Automotive-qualified (AEC-Q100), wider temp range (−40 °C to +150 °C), but lacks pre-bias startup and internal VDRV LDO | Choose TPS54560QDGQRQ1 only for automotive environments requiring AEC-Q100; verify compatibility with pre-charged outputs |
Compared with MP2451DT-LF-Z and TPS54560QDGQRQ1, the SIC478ED-T1-GE3 delivers higher integration (dual MOSFETs, internal LDOs, and compensation), wider input range (4.5–55 V), and unique features like pre-bias startup and programmable valley OCP - making it optimal for space-constrained industrial and telecom 5 A point-of-load designs.
Availability
SIC478ED-T1-GE3 is available at Aetrix Electronics and suitable for industrial motor drives, telecom base station power, robotics actuator control, and PLC I/O modules requiring stable component supply across extended temperature and input voltage ranges.
Supply support for SIC478ED-T1-GE3 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
Vishay Siliconix is a global leader in discrete semiconductors and passive components, specializing in high-reliability power management solutions for industrial, automotive, and computing markets.
The SiC47x family - including SIC478ED-T1-GE3 - was designed specifically for high-density, wide-input synchronous buck conversion in space-constrained industrial and telecom equipment, emphasizing thermal robustness, fast transient response, and simplified design-in.
FAQ
What is the maximum output current rating of the SIC478ED-T1-GE3?
The SIC478ED-T1-GE3 is rated for 5 A continuous output current. This is confirmed in the Vishay datasheet (S25-1437-Rev. I) under "Scalable solution 3 A (SiC479), 5 A (SiC478), 8 A (SiC477), 12 A (SiC476)" and verified in the Absolute Maximum Ratings table. The device sustains this current with proper thermal management using the MLP55-27L package's 12 °C/W junction-to-ambient thermal resistance.
How does the ILIMIT pin configure overcurrent protection on the SIC478ED-T1-GE3?
The ILIMIT pin on the SIC478ED-T1-GE3 selects valley current limit thresholds: tying to AGND sets 3 A, leaving floating sets 4.2 A, and tying to VDD sets 6 A. These values are explicitly listed in the Electrical Specifications table under "SiC478 valley current limit" and apply only to the SIC478ED-T1-GE3 variant - not the broader SiC47x family. No external sensing resistor is required.
Does the SIC478ED-T1-GE3 support pre-bias startup, and how does it behave?
Yes, the SIC478ED-T1-GE3 supports pre-bias startup. When the FB pin senses voltage above the internal soft-start ramp at enable, the control logic inhibits both high-side and low-side FET switching to prevent negative current flow and output voltage collapse. This behavior is documented in the "Pre-Bias Start-Up" section (page 8) and confirmed in Fig. 7 of the datasheet.
What is the purpose of the VCIN pin on the SIC478ED-T1-GE3, and can it be supplied independently of VIN?
The VCIN pin powers the internal VDD and VDRV LDOs. It can be supplied independently from VIN - e.g., from a lower auxiliary rail ≥5 V - to reduce linear regulator losses and improve efficiency. The datasheet specifies VCIN operates from 4.5 V to 55 V and recommends an RC filter to VIN or direct connection to a clean 5–12 V source. This flexibility is critical for high-input-voltage applications where VIN may exceed 30 V.
Is the SIC478ED-T1-GE3 internally compensated, and what does that mean for external component selection?
Yes, the SIC478ED-T1-GE3 is fully internally compensated. This means no external Type II or Type III compensation network is required - the loop is stable with any output capacitor type (ceramic, polymer, or electrolytic) and value. As stated in the datasheet: "No external ESR network is required for loop stability purpose." Designers select output capacitance solely based on ripple, transient, and physical constraints - not stability tuning.
SIC478ED-T1-GE3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay Siliconix
- Series:
- microBUCK®
- Package/Case:
- PowerPAK® MLP55-27
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 55V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 24V
- Current - Output:
- 5A
- Frequency - Switching:
- 100kHz ~ 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 105°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- PowerPAK® MLP55-27
SIC478ED-T1-GE3 FAQ
1.How can I place an order for SIC478ED-T1-GE3 through Aetrix?
Please submit a Request for Quotation (RFQ) for SIC478ED-T1-GE3 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 SIC478ED-T1-GE3 reliable?
The price and inventory of SIC478ED-T1-GE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SIC478ED-T1-GE3 is usually 5 days.
3.What payment methods are accepted for SIC478ED-T1-GE3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SIC478ED-T1-GE3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SIC478ED-T1-GE3?
SIC478ED-T1-GE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SIC478ED-T1-GE3 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 SIC478ED-T1-GE3?
For technical support, including SIC478ED-T1-GE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SIC478ED-T1-GE3 requirements.
6.How does Aetrix verify that SIC478ED-T1-GE3 is sourced from the original manufacturer or authorized distributors?
All SIC478ED-T1-GE3 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 SIC478ED-T1-GE3 meets industry standards.
7.What is the process for return or replacement of SIC478ED-T1-GE3?
All SIC478ED-T1-GE3 units undergo pre-shipment inspection (PSI). If there is an issue with SIC478ED-T1-GE3, 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 SIC478ED-T1-GE3 part is unused and in its original packaging.
Return procedure for SIC478ED-T1-GE3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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