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STMicroelectronics STHS2377AM6F
- Part No.:
- STHS2377AM6F
- Manufacturer:
- STMicroelectronics
- Category:
- Power Over Ethernet (PoE) Controllers
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STHS2377AM6F.pdf
- Description:
- IC POE CNTRL 1 CHANNEL 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,695
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Product details
Overview
STHS2377AM6F from STMicroelectronics is an IEEE 802.3af-compliant Powered Device (PD) interface controller for Power over Ethernet systems, integrating a 100V/500mA low-side MOSFET, resistor-programmable inrush current limit (140mA typical), legacy-mode UVLO (35.1V rising / 30.5V falling), and auto-retry fault recovery. It enables PoE power handshaking and hot-swap protection in VoIP phones and WLAN access points.
For engineers reviewing the STHS2377AM6F datasheet, STHS2377AM6F pinout, STHS2377AM6F application, or STHS2377AM6F equivalent, key selection criteria include legacy UVLO threshold compatibility, classification resistor support (Class 0–4), integrated MOSFET RDS(ON) (0.72–1.0 Ω), PG open-drain signaling referenced to RTN, and SO8 package thermal performance in industrial ambient (–40 to +85°C).
Technical Context
The STHS2377AM6F implements IEEE 802.3af PD detection via 24.9kΩ DET resistor and classification via external CLASS resistor (255–4420 Ω), supporting Class 0–4 power negotiation. Its internal 10V regulator powers control circuitry while the integrated MOSFET handles up to 461mA normal operation current with 0.1Ω sense path.
Legacy UVLO mode uses fixed internal thresholds (35.1V rise / 30.5V fall) without external divider dependency, distinguishing it from programmable (STHS2376x) and standard (STHS2375x) variants. The auto-retry behavior resets after thermal or overcurrent faults, enabling recovery without manual intervention in deployed edge devices.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| IEEE Compliance | Fully compliant with IEEE 802.3af PD interface requirements for detection, classification, and inrush control. |
| UVLO Threshold | 35.1 V (rising), 30.5 V (falling); fixed legacy mode eliminates need for external resistor divider on UVLO pin. |
| Normal Current Limit | 461 mA typical; sets maximum continuous load current before thermal shutdown or foldback activation. |
| Inrush Current Limit | 140 mA typical (RILIM = 178 kΩ); prevents PSE tripping during initial power-up of capacitive loads. |
| MOSFET RDS(ON) | 0.72–1.0 Ω at 300 mA; determines conduction loss and thermal dissipation in series power path. |
| Power Good Output | Open-drain PG referenced to RTN; active-high signal indicates MOSFET fully on and stable operation. |
| Operating Temp | –40°C to +85°C ambient; validated for industrial-grade deployment in uncontrolled environments. |
Pinout & Package
STHS2377AM6F is housed in an 8-pin SO (SO8, 150 mils width, ECOPACK® RoHS-compliant) package with 1.27 mm pitch and 5.0 × 4.0 mm body dimensions. Thermal pad not present; junction-to-ambient θJA ≈ 120°C/W per SO8 standard.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 ILIM | Inrush current limit programming input | Connects to VSS via resistor (62.5–500 kΩ); sets startup current limit per IILIM = 25,000/RILIM (A). |
| 2 CLASS | Classification resistor connection | Connects to VSS via 255–4420 Ω resistor to declare IEEE 802.3af power class (0–4) to PSE. |
| 3 DET | Detection resistor connection | Connects to VDD via 24.9 kΩ ±1% resistor to enable PSE detection of valid PD signature. |
| 4 VSS | PSE-side ground return | Input-side reference for detection/classification circuits and MOSFET source terminal. |
| 5 RTN | Load-side negative output rail | Current-carrying return path to downstream DC/DC converter; referenced for PG output and current sensing. |
| 6 PG | Power Good status output | Open-drain, active-high signal referenced to RTN; high-impedance = normal operation; low = fault or startup. |
| 7 UVLO | No Connect (NC) | Not used in STHS2377x; internally configured for legacy UVLO thresholds; leave unconnected. |
| 8 VDD | Input/output positive power rail | Accepts 0–57 V PoE input; supplies internal regulator and drives external TVS clamp (e.g., SMAJ58A). |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 100V/500mA MOSFET | Eliminates external switch; supports full PoE voltage transients and 461mA steady-state load current. |
| Resistor-programmable inrush limit | Enables precise control of startup surge (100–180 mA range) to avoid PSE false disconnects. |
| Legacy UVLO mode | Fixed 35.1V/30.5V thresholds ensure compatibility with older PSE implementations lacking programmable UVLO support. |
| Auto-retry fault recovery | Automatically re-attempts power-up after thermal or overcurrent faults-no manual reset required. |
| Open-drain PG referenced to RTN | Provides unambiguous system-level power status signal compatible with isolated downstream converters. |
Applications
| VoIP Phones | WLAN Access Points |
|---|---|
|
Use Scenario: Powered via Category 5 Ethernet cabling in enterprise desk phones with integrated speaker/mic and SIP stack. IC Role / Device Role / Timing Role: PD interface controller managing detection, classification, inrush limiting, and power-good signaling to enable safe PoE handshaking and DC/DC enable. Use Value: Enables single-cable deployment without local AC adapter; legacy UVLO ensures interoperability with installed base of Cisco and Avaya PSEs. |
Use Scenario: Ceiling-mounted 802.11n/g AP drawing up to 12.95W from midspan or endspan PSE in retail or office environments. IC Role / Device Role / Timing Role: Hot-swap controller regulating inrush into bulk capacitance and providing fault-isolated PG signal to enable RF subsystem sequencing. Use Value: Prevents PSE overload during AP boot; auto-retry allows recovery from transient overloads caused by antenna switching or firmware updates. |
| Web Cameras | POS Terminals |
|
Use Scenario: HD IP camera with IR illumination and motion detection deployed in surveillance systems using existing LAN infrastructure. IC Role / Device Role / Timing Role: PD interface ensuring reliable detection under varying cable lengths and powering downstream image sensor and video encoder rails. Use Value: Integrated MOSFET and 24.9kΩ DET resistor simplify BOM; SO8 package supports compact PCB layout near RJ-45 connector. |
Use Scenario: Point-of-sale terminal with barcode scanner, display, and EMV reader powered over Ethernet in retail checkout lanes. IC Role / Device Role / Timing Role: Primary PoE interface enforcing Class 3 (6.49–12.95W) classification and delivering clean, monitored power to safety-critical payment subsystems. Use Value: PG signal synchronizes secure element initialization; thermal shutdown protects against enclosure overheating in enclosed kiosk enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Powered Device interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STHS2375AM6F | Standard UVLO (39.3V/30.5V), same pinout and features otherwise | Designed for newer PSEs compliant with IEEE 802.3af baseline UVLO thresholds | Select when deploying with modern switches (e.g., Cisco Catalyst 9000 series) where legacy UVLO is unnecessary. |
| LT4275AIMSE#PBF | Linear Tech/Analog Devices; 100V rating, programmable UVLO, no integrated MOSFET (external FET required) | Requires external MOSFET and gate driver; higher BOM count but offers adjustable UVLO and more flexible fault management | Choose when design requires fine-grained UVLO tuning or higher current (>500mA) capability beyond STHS2377A's integrated switch. |
Compared with STHS2375AM6F, the STHS2377AM6F trades higher UVLO hysteresis tolerance for legacy PSE compatibility, while LT4275AIMSE#PBF shifts complexity to external components to gain configurability-making STHS2377AM6F optimal for cost-sensitive, drop-in PoE retrofit designs.
Availability
STHS2377AM6F is available at Aetrix Electronics and suitable for VoIP phones, WLAN access points, web cameras, and POS terminals requiring stable component supply across industrial temperature ranges and long-lifecycle deployments.
Supply support for STHS2377AM6F 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, designing and manufacturing analog, microcontroller, power, and automotive ICs with emphasis on energy efficiency and industrial reliability.
The STHS237x family was developed specifically for IEEE 802.3af PoE Powered Device interface applications, targeting simplified, integrated, and robust power handshaking in networked edge devices.
FAQ
What is the function of the UVLO pin on STHS2377AM6F?
The UVLO pin is a No Connect (NC) on STHS2377AM6F. This device uses internal fixed thresholds (35.1 V rising / 30.5 V falling) for undervoltage lockout and does not require external resistor divider configuration. Connecting anything to pin 7 may cause malfunction or damage.
Can STHS2377AM6F support IEEE 802.3at (PoE+) or 802.3bt?
No. STHS2377AM6F is strictly IEEE 802.3af-compliant and rated for up to 12.95W input power. It lacks the dual-signature detection, higher current limits, and extended classification protocols required for 802.3at (up to 30W) or 802.3bt (up to 90W) operation.
What is the recommended TVS diode for VDD–VSS protection?
STMicroelectronics specifies the SMAJ58A (58V standoff, 100W peak pulse power) between VDD and VSS pins. It clamps transients up to 100V and complements the device's absolute maximum rating, preventing latch-up or gate oxide damage during PoE cable insertion or lightning-induced surges.
How does the auto-retry mode behave after thermal shutdown?
After thermal shutdown triggers at 140°C junction temperature, the device disables the MOSFET, cools passively, and automatically attempts restart once die temperature falls below 120°C (20°C hysteresis). Up to three retries occur before latching off if fault persists-unlike STHS2377L which latches permanently.
STHS2377AM6F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Controller (PD)
- Number of Channels:
- 1
- Power - Max:
- 12.95 W
- Internal Switch(s):
- Yes
- Auxiliary Sense:
- No
- Standards:
- 802.3af (PoE)
- Voltage - Supply:
- 0V ~ 57V
- Current - Supply:
- 250µA
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
STHS2377AM6F FAQ
1.How can I place an order for STHS2377AM6F through Aetrix?
Please submit a Request for Quotation (RFQ) for STHS2377AM6F 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 STHS2377AM6F reliable?
The price and inventory of STHS2377AM6F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STHS2377AM6F is usually 5 days.
3.What payment methods are accepted for STHS2377AM6F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STHS2377AM6F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STHS2377AM6F?
STHS2377AM6F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STHS2377AM6F 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 STHS2377AM6F?
For technical support, including STHS2377AM6F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STHS2377AM6F requirements.
6.How does Aetrix verify that STHS2377AM6F is sourced from the original manufacturer or authorized distributors?
All STHS2377AM6F 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 STHS2377AM6F meets industry standards.
7.What is the process for return or replacement of STHS2377AM6F?
All STHS2377AM6F units undergo pre-shipment inspection (PSI). If there is an issue with STHS2377AM6F, 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 STHS2377AM6F part is unused and in its original packaging.
Return procedure for STHS2377AM6F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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