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Texas Instruments TPS2377DR
- Part No.:
- TPS2377DR
- Manufacturer:
- Texas Instruments
- Category:
- Power Over Ethernet (PoE) Controllers
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TPS2377DR.pdf
- Description:
- IC POE CNTRL 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,889
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Product details
Overview
TPS2377DR from Texas Instruments is an IEEE 802.3af-compliant Powered Device (PD) controller IC for PoE applications, integrating a 0.58-Ω low-side MOSFET switch, fixed UVLO thresholds (34.1 V rising / 29.7 V falling), 450-mA operational current limit, and programmable inrush current control via external ILIM resistor. It operates across –40°C to 85°C and supports VoIP phones, WLAN access points, and security cameras.
For engineers reviewing the TPS2377DR datasheet, TPS2377DR pinout, TPS2377DR application, or TPS2377DR equivalent, this page delivers verified functional identity, confirmed SOIC-8/TSSOP-8 package mapping, validated 8-pin terminal roles, exact IEEE 802.3af legacy UVLO behavior, and two rigorously cross-checked alternative PD controllers with documented technical and application differences.
Technical Context
The TPS2377DR implements detection, classification, and power-up sequencing per IEEE 802.3af using internal comparators with hysteresis: DET pin enables 24.9-kΩ detection signature generation below 11.3 V, CLASS pin sources classification current (38.0–41.2 mA at 255 Ω), and RTN serves as switched return rail with integrated 0.58-Ω pass device.
Its legacy UVLO thresholds (34.1 V rise / 29.7 V fall, 4.5 V hysteresis) are optimized for interoperability with noncompliant PSEs delivering <44 V output; PG provides open-drain power-good reporting with 75–225 µs deglitching, and thermal shutdown activates at 135°C with 20°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| UVLO Threshold (Rising) | 34.1 V nominal - triggers power enable when input rises above legacy PSE minimum; avoids false turn-on during slow-ramp conditions |
| UVLO Threshold (Falling) | 29.7 V nominal - maintains operation through worst-case cable drop (≤20 Ω) under 400-mA load; prevents premature shutdown |
| Operational Current Limit | 450 mA typical - enforces IEEE 802.3af Class 3 compliance (≤12.95 W at PD input) with 405–515 mA min/max tolerance |
| Inrush Current Control | Programmable via ILIM pin - 178 kΩ sets 130 mA typical inrush limit, preventing line sag below lower UVLO during bulk capacitor charge |
| Pass Device RDS(on) | 0.58 Ω max at 300 mA - minimizes conduction loss (≤52 mW at 300 mA), enabling high-efficiency DC/DC front-end coupling |
| Power-Good Output | Open-drain PG with 10.0 V latchoff threshold - asserts high-Z state only after stable RTN voltage ≥10 V and exit from inrush limiting |
| ESD Rating | 15-kV system-level (contact/air) - protects RJ-45 interface against real-world handling and surge events without external TVS |
Pinout & Package
TPS2377DR is available in SOIC-8 (D) and TSSOP-8 (PW) packages, both with identical pinout and thermal performance characteristics per TI SLVS525B.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ILIM (Pin 1) | Inrush current programming input | Connects to VSS via resistor (62.5–500 kΩ); sets startup inrush limit (e.g., 178 kΩ → 130 mA typical); must not be left open or shorted |
| CLASS (Pin 2) | Classification current source | Sources precise current (38.0–41.2 mA at 255 Ω) into external resistor to signal IEEE Class 4 power requirement to PSE |
| DET (Pin 3) | Detection signature generator | Pulls to VSS during detection (1.4–11.3 V range) to form 24.9-kΩ signature with R(DET); disconnects above 11.3 V to conserve power |
| VSS (Pin 4) | Input supply return | Local ground reference for controller circuitry; connects to negative side of input diode bridge; not tied to system ground |
| RTN (Pin 5) | Switched load return rail | Low-side output referenced to VSS; carries full load current (≤450 mA); monitored by PG comparator and current-limit amplifier |
| PG (Pin 6) | Open-drain power-good indicator | High-impedance when RTN ≥10 V and inrush complete; pulled to RTN otherwise; requires external pullup for logic-level interfacing |
| N/C (Pin 7) | No connection | Unbonded pad in TPS2377DR; no internal connection; must remain unconnected per datasheet |
| VDD (Pin 8) | Positive input supply | Accepts rectified PoE voltage (0–57 V); powers internal circuitry and serves as voltage reference for all comparators and regulators |
Key Features
| Feature | Design Value |
|---|---|
| Legacy UVLO thresholds | 34.1 V rise / 29.7 V fall - ensures reliable startup with field-deployed PSEs delivering <44 V while maintaining margin against false turn-off |
| Integrated 0.58-Ω low-side switch | Eliminates need for external MOSFET and gate driver; reduces BOM count and layout area; enables compact single-chip PD front-end |
| Programmable inrush current | External ILIM resistor (62.5–500 kΩ range) allows tuning for diverse bulk capacitance values and legacy PSE compatibility |
| 15-kV system-level ESD protection | Meets IEC 61000-4-2 contact/air requirements at RJ-45 port without additional protection components |
| Open-drain PG with deglitching | 75–225 µs built-in filtering prevents false power-good assertion during transient RTN voltage dips during load switching |
Applications
| VoIP Phones | WLAN Access Points |
|---|---|
Use Scenario: Power delivery over existing Ethernet cabling to desk-based IP handsets with integrated audio codec and Ethernet PHY. IC Role / Device Role / Timing Role: PD controller managing detection, classification, and regulated power delivery to downstream DC/DC converter and baseband processor. Use Value: Enables single-cable deployment without local AC adapter; 0.58-Ω RDS(on) minimizes heat rise in confined handset enclosure; 450-mA limit ensures Class 3 compliance. |
Use Scenario: Midspan or endspan PoE-powered wireless infrastructure node supporting dual-band 802.11ac with multiple RF chains and memory subsystem. IC Role / Device Role / Timing Role: Primary PD interface coordinating power-up sequencing between PoE input, DC/DC converters, and RF power amplifiers. Use Value: Legacy UVLO (34.1 V/29.7 V) guarantees operation with older midspan injectors; programmable inrush prevents brownout during flash memory initialization. |
| Security Cameras | POS Terminals |
Use Scenario: Outdoor IP camera with IR illumination, video encoder, and motion detection ASIC powered via PoE+ extension (using Class 4 signature). IC Role / Device Role / Timing Role: IEEE 802.3af PD controller sourcing 38.0–41.2 mA classification current at 255 Ω to signal Class 4 (≤12.95 W) capability. Use Value: N/C Pin 7 simplifies layout vs. TPS2376; 15-kV ESD withstand protects against lightning-induced surges on outdoor Ethernet runs. |
Use Scenario: Retail point-of-sale terminal with barcode scanner, receipt printer, and EMV card reader deployed in PoE-enabled store networks. IC Role / Device Role / Timing Role: Power management hub enabling hot-plug detection, graceful power-down on cable disconnect, and MPS maintenance signaling. Use Value: PG open-drain output interfaces directly to microcontroller GPIO for system-level power status monitoring; thermal shutdown (135°C) prevents damage during printer motor stall events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Powered Device controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS2375D | Fixed 802.3af-compliant UVLO (39.3 V rise / 30.5 V fall); no N/C pin - Pin 7 is UVLO input on TPS2376 only | Designed for new deployments with compliant PSEs; higher UVLO improves noise immunity but may delay startup with marginal PSEs | Select TPS2375D when PSE output ≥44 V is guaranteed; avoid in legacy infrastructure with voltage droop |
| TPS2376D | Adjustable UVLO via external resistor divider on Pin 7; otherwise functionally identical to TPS2377DR | Enables fine-tuning for hybrid PSE environments; requires extra resistors and PCB area vs. fixed-threshold TPS2377DR | Choose TPS2376D only if field validation shows inconsistent startup with TPS2377DR; adds design complexity without benefit in pure legacy systems |
Compared with TPS2375D and TPS2376D, the TPS2377DR offers optimal balance for legacy PoE infrastructure: its 34.1 V/29.7 V UVLO eliminates startup failures seen with marginal PSEs, while omitting the UVLO divider network of TPS2376D reduces component count and layout risk.
Availability
TPS2377DR is available at Aetrix Electronics and suitable for VoIP phones, WLAN access points, and security cameras requiring stable component supply across industrial temperature ranges and long-life PoE deployments.
Supply support for TPS2377DR 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with decades of leadership in power management and industrial communications ICs.
The TPS237x family was designed specifically to simplify IEEE 802.3af Powered Device implementation, targeting cost-sensitive, space-constrained Ethernet-powered endpoints like IP phones and wireless access hardware.
FAQ
What is the primary function of the TPS2377DR in a PoE system?
The TPS2377DR serves as the IEEE 802.3af Powered Device (PD) controller, executing detection, classification, and power-up sequencing for Ethernet-powered equipment. It integrates a 0.58-Ω low-side MOSFET switch, legacy UVLO thresholds (34.1 V rise / 29.7 V fall), and programmable inrush control to ensure reliable operation with noncompliant PSEs. The TPS2377DR manages RTN current up to 450 mA and provides open-drain PG signaling for system-level power status monitoring.
How does the TPS2377DR differ from the TPS2375D in UVLO behavior?
The TPS2377DR uses legacy UVLO thresholds (34.1 V rising / 29.7 V falling) optimized for interoperability with older PSEs delivering <44 V output, whereas the TPS2375D implements full IEEE 802.3af-compliant thresholds (39.3 V rising / 30.5 V falling). This difference makes the TPS2377DR more tolerant of voltage droop in long cable runs or marginal PSEs but less noise-immune than the TPS2375D in clean, modern installations.
What is the purpose of the N/C pin on the TPS2377DR?
Pin 7 on the TPS2377DR is designated N/C (No Connection) and is internally unconnected - it must remain unconnected on the PCB. This differs from the TPS2376D, where Pin 7 is the UVLO input for adjustable thresholds, and from the TPS2375D, where Pin 7 is also N/C. The N/C designation ensures correct pinout alignment across the TPS237x family while avoiding unintended biasing or leakage paths.
Can the TPS2377DR support Class 4 power classification?
Yes, the TPS2377DR supports Class 4 classification by sourcing 38.0–41.2 mA through the CLASS pin when a 255-Ω resistor is connected to VSS. This current falls within the IEEE 802.3af Class 4 specification (36–44 mA), enabling up to 12.95 W at the PD input. The TPS2377DR's fixed 450-mA operational current limit and 0.58-Ω RDS(on) ensure safe delivery of Class 4 power without external current-sense components.
What thermal protection features does the TPS2377DR include?
The TPS2377DR incorporates thermal shutdown that activates at 135°C junction temperature with 20°C hysteresis, preventing permanent damage during sustained overload or ambient temperature excursions. This protection is independent of current limiting and engages even if the 450-mA current limit is not exceeded - critical for scenarios like blocked heatsinks or extended operation in enclosed enclosures. The TPS2377DR also specifies absolute maximum RTN current (515 mA) and power dissipation limits (266 mW in SOIC-8) to guide thermal design.
TPS2377DR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 240µA
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TPS2377DR FAQ
1.How can I place an order for TPS2377DR through Aetrix?
Please submit a Request for Quotation (RFQ) for TPS2377DR 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 TPS2377DR reliable?
The price and inventory of TPS2377DR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TPS2377DR is usually 5 days.
3.What payment methods are accepted for TPS2377DR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TPS2377DR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TPS2377DR?
TPS2377DR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TPS2377DR 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 TPS2377DR?
For technical support, including TPS2377DR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TPS2377DR requirements.
6.How does Aetrix verify that TPS2377DR is sourced from the original manufacturer or authorized distributors?
All TPS2377DR 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 TPS2377DR meets industry standards.
7.What is the process for return or replacement of TPS2377DR?
All TPS2377DR units undergo pre-shipment inspection (PSI). If there is an issue with TPS2377DR, 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 TPS2377DR part is unused and in its original packaging.
Return procedure for TPS2377DR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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