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STMicroelectronics STEF512GR
- Part No.:
- STEF512GR
- Manufacturer:
- STMicroelectronics
- Category:
- Current Regulation/Management
- Package:
- SOT-23-8 Thin, TSOT-23-8
- Datasheet:
-
STEF512GR.pdf
- Description:
- POWER MANAGEMENT
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
STEF512GR from STMicroelectronics is a dual-channel integrated electronic fuse (eFuse) designed for independent 5 V and 12 V rail protection in hot-swap and inrush-controlled systems. It features factory-trimmed current limits (3 A typ. on 5 V, 4 A typ. on 12 V), precise overvoltage clamping (5.7 V and 15.0 V typ.), integrated 40 mΩ Power FETs, and adjustable dV/dt via external soft-start capacitors. It is deployed in HDD/SSD drives and storage arrays requiring fault-robust power delivery.
For engineers reviewing the STEF512GR datasheet, STEF512GR pinout, STEF512GR application, or STEF512GR equivalent, key selection considerations include per-rail UVLO thresholds (4.35 V / 9.7 V), thermal shutdown behavior (165 °C, latched-off), SAS disable logic (active-low EN), and TSOT23-8L package constraints for high-density board layout.
Technical Context
The STEF512GR embeds two independent analog control loops: one for output voltage clamping (via VGS regulation during input overvoltage), and one for current limiting (using sense-FET topology to enforce factory-set ILim values). Each channel operates autonomously with dedicated VIN/VOUT pins, soft-start pins (SS5/SS12), and thermal shutdown detection.
Startup sequencing is user-programmable via external CSS capacitors, enabling controlled ramp rates (11–15 ms for 5 V, 10–14 ms for 12 V). The device remains latched off after thermal shutdown until EN is toggled low or power is cycled - no automatic recovery - ensuring safe manual intervention before restart.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Current limit (5 V) | 3 A typical; factory-trimmed overload threshold preventing sustained overcurrent damage to downstream circuitry |
| Current limit (12 V) | 4 A typical; enables robust protection of higher-power storage subsystems without external current-sense components |
| Voltage clamp (5 V) | 5.7 V typical at VIN_5 = 8 V; limits output to safe level during upstream supply overvoltage faults |
| Voltage clamp (12 V) | 15.0 V typical at VIN_12 = 17 V; prevents load damage from 12 V rail overvoltage events |
| RDS(on) (5 V) | 36 mΩ typical at 25°C; minimizes conduction loss and voltage drop (<180 mV @ 5 A) under normal operation |
| RDS(on) (12 V) | 40 mΩ typical at 25°C; ensures low insertion loss for 12 V loads while maintaining thermal margin |
| UVLO threshold (5 V) | 4.35 V typical rising; prevents turn-on until stable 5 V rail is established, avoiding brownout instability |
| UVLO threshold (12 V) | 9.7 V typical rising; guarantees reliable startup only when 12 V supply meets minimum operational voltage |
Pinout & Package
STEF512GR is housed in a thermally enhanced TSOT23-8L package (2.9 mm × 2.8 mm × 0.9 mm), optimized for space-constrained storage and set-top box PCBs. Its exposed pad improves thermal dissipation (RthJC = 25.5 °C/W) and supports reflow-compatible assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN_12 | 12 V input supply rail | Main power entry for 12 V channel; rated up to 25 V absolute max; connects to bulk input capacitor |
| SS12 | 12 V soft-start adjustment | Accepts external capacitor to set dV/dt ramp time (10–14 ms); must not be left floating |
| SS5 | 5 V soft-start adjustment | Accepts external capacitor to set dV/dt ramp time (11–15 ms); enables independent inrush control per rail |
| VIN_5 | 5 V input supply rail | Main power entry for 5 V channel; rated up to 25 V absolute max; decoupled with ≥1 µF input capacitance |
| VOUT_5 | 5 V regulated output | Protected 5 V output to HDD/SSD logic or interface circuitry; clamped at 5.7 V during overvoltage |
| GND | Power and signal reference | Common return path for both channels; requires low-impedance connection to minimize noise coupling |
| EN | SAS disable input | Active-low enable; internally pulled down (1 MΩ); logic-high disables both channels simultaneously |
| VOUT_12 | 12 V regulated output | Protected 12 V output to HDD spindle motor or SSD power stage; clamped at 15.0 V during overvoltage |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent eFuses | Separate 5 V and 12 V protection channels with isolated control loops, enabling concurrent but non-interfering fault management |
| Adjustable soft-start | Per-channel dV/dt control via external SSx capacitors - eliminates inrush-induced voltage droop and system reset |
| Precise overvoltage clamp | Factory-trimmed VCLAMP (5.7 V / 15.0 V typ.) with <±0.2 V variation over temperature - replaces discrete Zener+MOSFET solutions |
| Latched thermal shutdown | 165 °C shutdown with 20 °C hysteresis; forces manual reset via EN toggle or power cycle - prevents uncontrolled auto-retry during persistent faults |
| Integrated low-RDS(on) FETs | 40 mΩ max RDS(on) per channel at 25°C - reduces board area, BOM count, and conduction losses vs. discrete eFuse IC + external MOSFET |
Applications
| Enterprise SSD Arrays | HDD Hot-Swap Backplanes |
|---|---|
|
Use Scenario: Multiple SSDs inserted/removed under power in 1U server chassis with shared 5 V/12 V backplane rails. IC Role / Device Role / Timing Role: Dual-rail eFuse providing independent overcurrent and overvoltage protection per drive slot, with programmable soft-start to prevent bus collapse during insertion. Use Value: Enables true hot-swap compliance without auxiliary sequencing ICs; clamps transients from failing PSU or miswired cables before damaging NVMe controllers. |
Use Scenario: Rack-mounted storage enclosures where individual 3.5" HDDs are serviced without powering down the entire system. IC Role / Device Role / Timing Role: Per-drive 5 V logic and 12 V motor power switch with UVLO, current limiting, and thermal latch - isolates faulty drives without affecting others. Use Value: Eliminates need for mechanical interlocks or complex FPGA-based power sequencing; reduces field failure rate from inrush-induced voltage sag. |
| Set-Top Box Power Distribution | Industrial RAID Controllers |
|
Use Scenario: Consumer STB with multiple tuners, demodulators, and USB peripherals sharing a single AC/DC adapter. IC Role / Device Role / Timing Role: Centralized 5 V/12 V rail protector that enforces clean power-up sequencing and absorbs transient surges from switching regulators or ESD events. Use Value: Prevents firmware corruption caused by brownout resets; clamps 12 V rail overvoltage from failed DC-DC converter before damaging HDMI PHY or SoC I/O. |
Use Scenario: Industrial RAID controller board managing up to 12 SATA drives with redundant power inputs. IC Role / Device Role / Timing Role: Dual-rail eFuse per drive bay, coordinated via EN pin to support firmware-initiated power cycling and predictive thermal shutdown. Use Value: Supports remote diagnostics and maintenance without physical access; latched-off state prevents automatic restart during thermal stress testing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-rail eFuse applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TUSB546IRWBR | Single 5 V USB Type-C port protector; no 12 V channel, no adjustable soft-start, lower current limit (3 A max) | Designed for USB PD compliance, not general-purpose dual-rail storage protection | Select only for USB-centric designs requiring CC logic; lacks independent 12 V rail handling and thermal latch |
| TPS259472ARPWR | Dual-channel eFuse with 5.5 V/16 V max input, but fixed 3.3 V/5 V outputs - no native 12 V rail support | Targeted at low-voltage compute modules; requires external boost or LDO for 12 V loads | Use when system uses only ≤5.5 V rails; unsuitable for direct 12 V HDD/SSD power without added conversion stages |
Compared with TUSB546IRWBR and TPS259472ARPWR, STEF512GR uniquely integrates matched 5 V and 12 V protection with factory-trimmed clamping, latched thermal response, and per-rail soft-start - eliminating external components required by alternatives to achieve equivalent storage-grade reliability.
Availability
STEF512GR is available at Aetrix Electronics and suitable for enterprise SSD arrays, HDD hot-swap backplanes, and set-top box power distribution requiring stable component supply across extended product lifecycles.
Supply support for STEF512GR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering innovative analog, power, and microcontroller solutions for industrial, automotive, and consumer markets.
The STEF512GR belongs to ST's eFuse and load switch portfolio, engineered specifically for high-reliability storage and broadcast equipment where simultaneous 5 V/12 V rail protection, hot-swap capability, and thermal safety are mandatory.
FAQ
What is the function of the EN pin, and how should it be interfaced?
The EN pin is an active-low SAS (System Alert Signal) disable input. When pulled low (≤0.7 V), the device enables both 5 V and 12 V channels; when high (≥2.1 V), it disables them. It features an internal 1 MΩ pull-down resistor, so leaving it unconnected defaults to enabled operation. For firmware-controlled power cycling, connect EN to a GPIO with open-drain or push-pull output capable of sinking ≥10 µA.
How does the soft-start capacitor value affect startup behavior?
The capacitor connected between SS5 or SS12 and GND directly sets the output voltage slew rate: larger capacitance yields slower ramp (e.g., 100 nF → ~13 ms for 5 V). This controls inrush current into downstream bulk capacitance (COUT). Values outside 1–100 nF may cause unstable ramping or excessive delay; ST recommends 47 nF for balanced startup time and surge suppression in typical HDD/SSD applications.
Can STEF512GR protect against reverse polarity or reverse current?
No. STEF512GR provides forward-direction overcurrent, overvoltage, and thermal protection only. It does not block reverse current flow or tolerate reverse input polarity. External reverse-polarity protection (e.g., ideal diode controller or series Schottky) must be added upstream if the application risks negative input voltage or backfeed from downstream loads.
What happens after thermal shutdown, and how is recovery performed?
Upon reaching 165 °C junction temperature, STEF512GR latches off - both channels disconnect permanently until manually reset. Recovery requires either toggling EN from high to low (with ≥100 µs pulse width) or performing a full power cycle. The device will not auto-restart even after cooling below 145 °C (165 °C − 20 °C hysteresis), ensuring deliberate system-level fault acknowledgment before re-enabling power.
STEF512GR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- SOT-23-8 Thin, TSOT-23-8
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Electronic Fuse
- Sensing Method:
- High-Side
- Accuracy:
- -
- Voltage - Input:
- 5V, 12V
- Current - Output:
- 3A
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-23-8L
STEF512GR FAQ
1.How can I place an order for STEF512GR through Aetrix?
Please submit a Request for Quotation (RFQ) for STEF512GR 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 STEF512GR reliable?
The price and inventory of STEF512GR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STEF512GR is usually 5 days.
3.What payment methods are accepted for STEF512GR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STEF512GR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STEF512GR?
STEF512GR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STEF512GR 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 STEF512GR?
For technical support, including STEF512GR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STEF512GR requirements.
6.How does Aetrix verify that STEF512GR is sourced from the original manufacturer or authorized distributors?
All STEF512GR 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 STEF512GR meets industry standards.
7.What is the process for return or replacement of STEF512GR?
All STEF512GR units undergo pre-shipment inspection (PSI). If there is an issue with STEF512GR, 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 STEF512GR part is unused and in its original packaging.
Return procedure for STEF512GR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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