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Texas Instruments TPS2377DRG4
- Part No.:
- TPS2377DRG4
- Manufacturer:
- Texas Instruments
- Category:
- Power Over Ethernet (PoE) Controllers
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TPS2377DRG4.pdf
- Description:
- IC POE CNTRL 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,725
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Product details
Overview
TPS2377DRG4 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 ILIM pin. It enables safe power delivery to VoIP phones, WLAN access points, and security cameras over Ethernet cabling.
For engineers reviewing the TPS2377DRG4 datasheet, TPS2377DRG4 pinout, TPS2377DRG4 application, or TPS2377DRG4 equivalent, key selection considerations include legacy PoE system compatibility (lower UVLO turn-on), thermal shutdown at 135°C, open-drain PG reporting, 15-kV system-level ESD rating, and SOIC-8 packaging with verified pin mapping.
Technical Context
The TPS2377DRG4 implements detection, classification, and undervoltage lockout using dedicated comparators with hysteresis-specifically tuned for legacy PSEs with lower output voltage compliance. Its functional block includes a 100-V-rated pass device, current-limit amplifier, and PG comparator referenced to RTN.
Unlike the TPS2375 (802.3af-optimized) and TPS2376 (adjustable UVLO), the TPS2377DRG4 uses fixed legacy UVLO thresholds (34.1 V / 29.7 V) and omits the UVLO pin; it shares identical DET, CLASS, ILIM, RTN, PG, VDD, and VSS pin functions and electrical behavior across the family, including 24.9-kΩ detection resistor support and 255–4420-Ω classification resistor range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| UVLO Threshold (Rising) | 34.1 V - Enables power-up earlier than TPS2375 to support legacy PSEs with <44 V output. |
| UVLO Threshold (Falling) | 29.7 V - Maintains operation through cable voltage sag; smaller hysteresis (4.5 V) vs. TPS2375 (8.8 V). |
| Pass Device rDS(on) | 0.58 Ω - Low conduction loss at 300 mA; supports up to 350 mA continuous RTN current. |
| Operational Current Limit | 450 mA (typical) - Fixed internal limit protects downstream DC/DC converter and load during steady-state. |
| Inrush Current Control | Programmable via ILIM pin (62.5–500 kΩ) - Enables controlled bulk capacitor charging; 178 kΩ yields ~130 mA typical. |
| Power-Good Output | Open-drain PG referenced to RTN - Asserts high-impedance state only after successful classification and exit from inrush. |
| ESD Rating | 15 kV system-level (contact/air) - Meets EN61000-4-2 requirements at RJ-45 interface without external protection. |
Pinout & Package
TPS2377DRG4 is housed in an 8-pin SOIC package (D suffix, RoHS-compliant, JEDEC MS-012AC). Pinout matches TPS2375/TPS2376 family: ILIM (1), CLASS (2), DET (3), VSS (4), RTN (5), PG (6), NC (7), VDD (8).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ILIM (1) | Inrush current programming input | Connects to VSS via resistor (62.5–500 kΩ); sets start-up inrush limit per TI Equation 1; not internally connected during detection. |
| CLASS (2) | Classification current source | Sinks current (27–39 mA) through external resistor (255–4420 Ω) during 13–21 V window to signal IEEE 802.3af Class 0–4. |
| DET (3) | Detection signature generator | Pulls to VSS during detection (1.4–11.3 V); forms 24.9-kΩ path with VDD to present 25-kΩ incremental resistance to PSE. |
| VSS (4) | Input return reference | Local ground for controller circuitry; serves as return for DET, CLASS, ILIM, and UVLO (not used on TPS2377). |
| RTN (5) | Switched load return | Low-side output rail for downstream DC/DC converter; current-sensing node for limit and PG monitoring. |
| PG (6) | Open-drain power-good indicator | High-impedance when RTN is enabled and inrush complete; pulled to RTN otherwise; requires external pullup for logic-level interface. |
| NC (7) | No connection | Unbonded pad; must remain unconnected; not UVLO pin (assigned only to TPS2376). |
| VDD (8) | Positive input supply | Accepts rectified PoE voltage (0–57 V); powers internal circuitry and serves as voltage monitor for all thresholds. |
Key Features
| Feature | Design Value |
|---|---|
| Legacy PoE UVLO tuning | 34.1 V turn-on / 29.7 V turn-off thresholds enable reliable startup with field-deployed PSEs below IEEE 802.3af minimum 44 V output. |
| Integrated 100-V pass switch | 0.58-Ω rDS(on) MOSFET eliminates need for external high-voltage switch; rated for 515 mA peak RTN current. |
| Programmable inrush control | ILIM pin allows precise adjustment of inrush current (100–180 mA typ.) to prevent PSE shutdown during bulk capacitor charge. |
| True open-drain PG reporting | PG referenced to RTN-not VSS-enables accurate status reporting even under varying load return conditions. |
| 15-kV system-level ESD robustness | Validated per EN61000-4-2 at RJ-45 interface; reduces need for external TVS diodes in cost-sensitive designs. |
Applications
| VoIP Phones | WLAN Access Points |
|---|---|
Use Scenario: Power delivery to dual-band 802.11ac access point with integrated PoE midspan injector. IC Role / Device Role / Timing Role: PD controller managing detection, classification, and inrush-limited power handoff to isolated DC/DC converter. Use Value: Enables single-cable deployment with guaranteed 12.95 W available at RTN, leveraging 255-Ω classification for Class 4 compliance. |
Use Scenario: Indoor ceiling-mounted AP requiring robust startup under variable cable length (≤100 m) and legacy switch infrastructure. IC Role / Device Role / Timing Role: Legacy-aware PD controller ensuring reliable turn-on despite PSE voltage sag below 44 V. Use Value: TPS2377DRG4's 34.1 V UVLO rising threshold prevents brownout-induced restart cycles common with older Cisco or HP switches. |
| Security Cameras | POS Terminals |
Use Scenario: Outdoor IP camera with heater and IR illuminator drawing burst current during night mode transition. IC Role / Device Role / Timing Role: Inrush-limited power switch enabling controlled bulk capacitor recharge before load activation. Use Value: Programmable ILIM (178 kΩ) limits inrush to 130 mA, preventing PSE current-limit trip while supporting 350 mA steady-state draw. |
Use Scenario: Retail point-of-sale terminal with magnetic stripe reader, display, and USB peripherals powered via PoE. IC Role / Device Role / Timing Role: Fault-tolerant PD controller providing PG assertion only after stable RTN voltage and thermal safety confirmation. Use Value: Open-drain PG referenced to RTN ensures accurate power-good signaling independent of ground loop shifts in multi-peripheral systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Powered Device controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS2375DRG4 | Higher UVLO (39.3 V rising / 30.5 V falling); larger hysteresis (8.8 V); optimized for IEEE 802.3af-compliant PSEs. | Better stability with modern PSEs (e.g., Ubiquiti, Netgear ProSAFE); may fail to start with older 37–42 V PSE outputs. | Select TPS2375DRG4 for new designs targeting full 802.3af compliance and maximum noise immunity. |
| TPS2376DRG4 | Adjustable UVLO via external resistor divider on UVLO pin; identical pinout except UVLO replaces NC (Pin 7). | Enables fine-tuned threshold setting for hybrid or custom PSEs; requires additional BOM component and layout space. | Choose TPS2376DRG4 when field interoperability spans multiple PSE generations and tunability justifies added complexity. |
Compared with TPS2375DRG4 and TPS2376DRG4, the TPS2377DRG4 delivers deterministic legacy compatibility without external components or design trade-offs-making it optimal for cost-sensitive, field-deployed equipment where PSE voltage headroom is constrained.
Availability
TPS2377DRG4 is available at Aetrix Electronics and suitable for VoIP phones, WLAN access points, security cameras, and POS terminals requiring stable component supply across industrial temperature range (-40°C to +85°C) and long-life PoE deployments.
Supply support for TPS2377DRG4 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 interface ICs.
The TPS237x family was designed specifically for IEEE 802.3af Powered Device control, addressing detection, classification, inrush management, and fault reporting in single-chip solutions for Ethernet-powered endpoints.
FAQ
What is the primary function of the TPS2377DRG4 in a PoE system?
The TPS2377DRG4 serves as a Powered Device (PD) controller that manages the full IEEE 802.3af power negotiation sequence-including detection, classification, and inrush-limited power delivery-for Ethernet-connected devices. It integrates a 100-V, 0.58-Ω low-side switch and provides open-drain PG reporting. The TPS2377DRG4 is specifically tuned for legacy PSEs with lower output voltage compliance, making it distinct from the TPS2375DRG4 and TPS2376DRG4 variants.
How does the UVLO behavior of the TPS2377DRG4 differ from the TPS2375DRG4?
The TPS2377DRG4 features fixed legacy UVLO thresholds: 34.1 V (rising) and 29.7 V (falling), with 4.5 V hysteresis. In contrast, the TPS2375DRG4 uses 39.3 V / 30.5 V thresholds and 8.8 V hysteresis for full 802.3af compliance. This lower turn-on voltage allows the TPS2377DRG4 to reliably start up with older PSEs delivering ≤42 V, whereas the TPS2375DRG4 may stall during slow-rising inputs. The TPS2377DRG4 has no UVLO pin-Pin 7 is NC.
Can the TPS2377DRG4 be used with a 255-Ω classification resistor?
Yes-the TPS2377DRG4 fully supports the full IEEE 802.3af classification resistor range (255 Ω to 4420 Ω), with 255 Ω corresponding to Class 4 (36–44 mA draw, up to 12.95 W at PD input). When R(CLASS) = 255 Ω, the TPS2377DRG4 draws 38.0–41.2 mA during classification (13–21 V), meeting specification limits. This configuration is commonly used in high-power VoIP phones and PTZ cameras.
What is the purpose of the ILIM pin on the TPS2377DRG4, and what resistor value is recommended?
The ILIM pin on the TPS2377DRG4 programs the inrush current limit by connecting an external resistor to VSS. A 178-kΩ, 1% resistor sets a typical inrush limit of 130 mA-optimized for compatibility with legacy PSEs and minimizing voltage sag during bulk capacitor charging. Values between 62.5 kΩ and 500 kΩ are supported, yielding inrush currents from 100 mA to 180 mA. Leaving ILIM open or shorted to VSS will disable inrush control and risk PSE shutdown.
Does the TPS2377DRG4 require an external pullup resistor on the PG pin?
Yes-the PG pin on the TPS2377DRG4 is an open-drain output referenced to RTN, not VSS. An external pullup resistor (typically 10 kΩ to VDD or system logic rail) is required to generate a valid logic-high signal when PG is asserted (i.e., after successful classification and exit from inrush). Without pullup, PG remains floating or pulled to RTN, preventing proper power-good indication to downstream circuitry.
TPS2377DRG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- 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
TPS2377DRG4 FAQ
1.How can I place an order for TPS2377DRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TPS2377DRG4 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 TPS2377DRG4 reliable?
The price and inventory of TPS2377DRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TPS2377DRG4 is usually 5 days.
3.What payment methods are accepted for TPS2377DRG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TPS2377DRG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TPS2377DRG4?
TPS2377DRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TPS2377DRG4 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 TPS2377DRG4?
For technical support, including TPS2377DRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TPS2377DRG4 requirements.
6.How does Aetrix verify that TPS2377DRG4 is sourced from the original manufacturer or authorized distributors?
All TPS2377DRG4 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 TPS2377DRG4 meets industry standards.
7.What is the process for return or replacement of TPS2377DRG4?
All TPS2377DRG4 units undergo pre-shipment inspection (PSI). If there is an issue with TPS2377DRG4, 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 TPS2377DRG4 part is unused and in its original packaging.
Return procedure for TPS2377DRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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