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Texas Instruments TPS2377DR-1
- Part No.:
- TPS2377DR-1
- Manufacturer:
- Texas Instruments
- Category:
- Power Over Ethernet (PoE) Controllers
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TPS2377DR-1.pdf
- Description:
- IC POE CNTRL 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,224
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Product details
Overview
TPS2377DR-1 from Texas Instruments is an IEEE 802.3af-compliant Powered Device (PD) controller IC for Power over Ethernet applications, integrating a 0.58-Ω low-side MOSFET switch, fixed 450-mA operational current limit, legacy UVLO thresholds (30.5 V turn-on / 35.1 V turn-off), and open-drain power-good (PG) reporting. It operates across –40°C to 85°C and supports VoIP phones, WLAN access points, and security cameras using TSSOP-8 packaging.
For engineers reviewing the TPS2377DR-1 datasheet, TPS2377DR-1 pinout, TPS2377DR-1 application, or TPS2377DR-1 equivalent, key selection considerations include its legacy UVLO behavior for compatibility with pre-2003 PoE infrastructure, inrush current programmability via ILIM, classification resistor support for Class 0–4, thermal shutdown at 135°C, and 15-kV system-level ESD robustness at the RJ-45 interface.
Technical Context
The TPS2377DR-1 implements detection, classification, and undervoltage lockout functions per IEEE 802.3af, with detection enabled below 11.3 V and classification active between 13 V and 21 V. Its internal comparator network includes hysteresis on UVLO (4.5 V typical), PG assertion at RTN ≥10.0 V, and inrush termination when RTN current falls below 91% of programmed limit.
It features a true open-drain PG output referenced to RTN, not VSS, and uses external resistors on CLASS (255–4420 Ω) and ILIM (62.5–500 kΩ) to configure power class and inrush behavior. The integrated 100-V, 0.58-Ω low-side switch enables direct connection to downstream DC/DC converters without external FETs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| UVLO Turn-On Threshold | 30.5 V nominal - enables PD power-up when PSE voltage exceeds legacy PoE lower limit |
| UVLO Turn-Off Threshold | 35.1 V nominal - maintains operation during cable voltage sag; 4.5 V hysteresis prevents oscillation |
| Operational Current Limit | 450 mA typical - sets maximum steady-state load current; protects against sustained overload |
| Inrush Current Programmability | 100–180 mA range via 62.5–500 kΩ ILIM resistor - prevents input voltage collapse during bulk capacitor charging |
| Classification Support | IEEE 802.3af Classes 0–4 via 255–4420 Ω CLASS resistor - enables PSE power budgeting and compliance verification |
| ESD Robustness | 15-kV system-level contact/air per EN61000-4-2 - ensures reliability at RJ-45 interface without external protection |
| Operating Temperature | –40°C to +85°C - qualified for industrial and outdoor networking equipment environments |
Pinout & Package
TPS2377DR-1 is housed in an 8-pin TSSOP package (PW-8), with exposed thermal pad for enhanced power dissipation. Pin functions are validated per TI SLVS525B datasheet and match the TPS2375/77 top-view layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ILIM (Pin 1) | Inrush current programming input | Connects to VSS via resistor (178 kΩ typical) to set startup current limit; must not be left floating or shorted |
| CLASS (Pin 2) | Power classification current source | Sinks classification current (27–39 mA) through external resistor to define IEEE Class 0–4; enables PSE power allocation |
| DET (Pin 3) | Detection signature generator | Pulls to VSS during detection phase via 24.9 kΩ resistor to present 25 kΩ incremental resistance to PSE |
| VSS (Pin 4) | Input supply return | Local ground reference for detection, classification, and UVLO circuits; connects to PSE negative rail |
| RTN (Pin 5) | Switched load return | Low-side output node for downstream DC/DC converter; carries full load current and serves as PG reference |
| PG (Pin 6) | Open-drain power-good indicator | High-impedance when RTN ≥10.0 V and inrush complete; requires external pullup for logic-level signaling |
| N/C (Pin 7) | No connection | Unbonded pin; must remain unconnected per TI design - differs from TPS2376's UVLO pin |
| VDD (Pin 8) | Positive input supply | Accepts rectified 36–57 V PoE input; powers internal circuitry and provides voltage monitoring for all thresholds |
Key Features
| Feature | Design Value |
|---|---|
| Legacy UVLO thresholds | 30.5 V turn-on / 35.1 V turn-off - optimized for interoperability with early PoE PSEs lacking full 802.3af compliance |
| Integrated low-side switch | 0.58-Ω rDS(on), 100-V rating - eliminates need for external MOSFET and reduces BOM count in PoE-powered endpoints |
| Programmable inrush control | Configurable 100–180 mA limit via ILIM resistor - prevents false UVLO dropout during capacitor charging |
| True open-drain PG output | RTN-referenced, 10.0 V assertion threshold - enables reliable power sequencing with downstream regulators independent of VSS |
| 15-kV system-level ESD | Tested per EN61000-4-2 at RJ-45 - meets ruggedness requirements for field-deployed network devices without added TVS diodes |
Applications
| VoIP Phones | WLAN Access Points |
|---|---|
Use Scenario: Powered via Category 5/6 cabling from centralized PoE switch in enterprise office deployments. IC Role / Device Role / Timing Role: PD controller managing detection, classification, and power delivery to baseband processor and audio codec. Use Value: Enables single-cable deployment with guaranteed 12.95 W input power and thermal shutdown protection at 135°C. |
Use Scenario: Indoor/outdoor wireless infrastructure requiring remote powering with minimal external components. IC Role / Device Role / Timing Role: Primary power management IC enabling IEEE 802.3af compliance and inrush limiting for RF front-end and MAC controller. Use Value: Reduces bill-of-materials by integrating switch, UVLO, and PG reporting - eliminating discrete FET and comparator solutions. |
| Security Cameras | POS Terminals |
Use Scenario: Outdoor IP cameras operating in temperature extremes (-40°C to +85°C) with long cable runs. IC Role / Device Role / Timing Role: Powered device controller ensuring stable startup under marginal PSE voltage and cable loss conditions. Use Value: Legacy UVLO thresholds prevent intermittent startup failures caused by slow-rising legacy PSE outputs. |
Use Scenario: Retail point-of-sale terminals deployed in mixed-vendor PoE environments including older switches. IC Role / Device Role / Timing Role: PD interface IC supporting Class 3 power delivery (6.49–12.95 W) with fault-safe current limiting. Use Value: Fixed 450-mA operational current limit ensures consistent overload protection regardless of PSE configuration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Powered Device controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS2375DR | Fixed 802.3af-compliant UVLO (39.3 V turn-on / 30.5 V turn-off); identical pinout and feature set except UVLO thresholds | Better suited for new designs targeting full IEEE 802.3af PSEs; higher turn-on threshold improves noise immunity | Select TPS2375DR when interfacing with modern PSEs meeting 44 V minimum output specification |
| TPS2376DR | Programmable UVLO via external resistor divider on UVLO pin; adds pin 7 functionality absent in TPS2377DR-1 | Required where variable UVLO hysteresis or custom turn-on thresholds are needed for nonstandard PSEs | Choose TPS2376DR only if adjustable UVLO is mandatory; otherwise TPS2377DR-1 offers simpler layout and lower cost |
Compared with TPS2375DR and TPS2376DR, the TPS2377DR-1 delivers deterministic startup behavior with legacy PSEs via fixed lower UVLO thresholds, avoids UVLO pin routing complexity, and maintains full functional equivalence in detection, classification, and inrush control - making it optimal for backward-compatible PoE endpoint upgrades.
Availability
TPS2377DR-1 is available at Aetrix Electronics and suitable for VoIP phones, WLAN access points, security cameras, and POS terminals requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing for industrial Ethernet deployments.
Supply support for TPS2377DR-1 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 PoE-powered device implementation, reducing external component count while delivering robust detection, classification, and power-switching functionality in compact packages.
FAQ
What is the primary function of the TPS2377DR-1 in a PoE system?
The TPS2377DR-1 serves as a Powered Device (PD) controller that manages the IEEE 802.3af handshake sequence - performing detection, classification, and undervoltage lockout - while integrating a 0.58-Ω low-side MOSFET switch to deliver power to downstream circuitry. Its legacy UVLO thresholds (30.5 V / 35.1 V) ensure reliable operation with older PoE infrastructure, and its open-drain PG output enables precise power sequencing. The TPS2377DR-1 is essential for enabling single-cable power+data delivery in VoIP phones, security cameras, and other networked endpoints.
How does the TPS2377DR-1 differ from the TPS2375DR in UVLO behavior?
The TPS2377DR-1 uses legacy UVLO thresholds (30.5 V turn-on, 35.1 V turn-off) optimized for compatibility with pre-2003 PoE PSEs that may not meet the full IEEE 802.3af 44 V minimum output requirement. In contrast, the TPS2375DR implements standard-compliant UVLO (39.3 V turn-on, 30.5 V turn-off) with greater hysteresis (8.8 V) for improved noise immunity in modern installations. Both share identical pinout, inrush control, classification, and switching functionality - the UVLO difference is the sole distinguishing factor affecting startup stability in marginal voltage conditions.
Can the TPS2377DR-1 support IEEE 802.3af Class 4 power delivery?
Yes, the TPS2377DR-1 fully supports IEEE 802.3af Class 4 via its CLASS pin: connecting a 255 Ω ±1% resistor between CLASS and VSS configures the device to draw 36–44 mA during classification, signaling Class 4 (6.49–12.95 W input power). This enables the PSE to allocate up to 30 W at the port (accounting for cable loss), and the TPS2377DR-1's 450-mA operational current limit and 0.58-Ω switch sustain the required load. Classification is verified per Table 1 in the SLVS525B datasheet.
What is the purpose of the ILIM pin on the TPS2377DR-1, and how is it configured?
The ILIM pin on the TPS2377DR-1 sets the inrush current limit during PD startup by connecting an external resistor (62.5–500 kΩ) to VSS. Using the recommended 178 kΩ resistor yields a 100–180 mA inrush limit, preventing input voltage sag that could trigger premature UVLO dropout. The TPS2377DR-1's internal circuitry converts this resistor value into a controlled current ramp, terminating inrush when RTN current falls below 91% of the programmed limit. Leaving ILIM unconnected or shorted violates the absolute maximum ratings and will damage the TPS2377DR-1.
Does the TPS2377DR-1 require an external pullup resistor on the PG pin?
Yes, the PG pin on the TPS2377DR-1 is an open-drain output referenced to RTN, not VSS, and requires an external pullup resistor (typically 10–100 kΩ to VDD or system rail) to generate a valid logic-high signal. PG asserts high-impedance when RTN ≥10.0 V and inrush is complete, allowing downstream circuitry to initiate power-on reset or enable DC/DC converters. Without the pullup, PG cannot drive a logic-high state, breaking power sequencing integrity. This design ensures compatibility with varying downstream voltage domains independent of the TPS2377DR-1's local ground.
TPS2377DR-1 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-1 FAQ
1.How can I place an order for TPS2377DR-1 through Aetrix?
Please submit a Request for Quotation (RFQ) for TPS2377DR-1 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-1 reliable?
The price and inventory of TPS2377DR-1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TPS2377DR-1 is usually 5 days.
3.What payment methods are accepted for TPS2377DR-1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TPS2377DR-1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TPS2377DR-1?
TPS2377DR-1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TPS2377DR-1 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-1?
For technical support, including TPS2377DR-1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TPS2377DR-1 requirements.
6.How does Aetrix verify that TPS2377DR-1 is sourced from the original manufacturer or authorized distributors?
All TPS2377DR-1 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-1 meets industry standards.
7.What is the process for return or replacement of TPS2377DR-1?
All TPS2377DR-1 units undergo pre-shipment inspection (PSI). If there is an issue with TPS2377DR-1, 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-1 part is unused and in its original packaging.
Return procedure for TPS2377DR-1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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