TPS2370PWR - IEEE 802.3af PoE PD Interface Switch | Texas Instruments
MPN： TPS2370PWR ✓ 啟用中TPS2370PWR 概覽
A PoE Powered Device Controller is a specialized interface IC that sits between the Power Sourcing Equipment (PSE) on the Ethernet switch and the application load. It performs the signature resistance, power classification (Class 0-4) and inrush-limited hot-swap turn-on mandated by IEEE 802.3af, then hands a regulated bulk rail to a downstream DC-DC converter. Within the broader Power-over-Ethernet taxonomy, the TPS2370PWR belongs to the PD controller category, which complements PSE controllers and DC-DC converters to form a complete PoE end-to-end solution.
Key features include 0.3-ohm internal FET on-resistance for low conduction loss, 100 V maximum input voltage on VPD for surge margin, integrated IEEE 802.3af detection signature (24.9 kohm) and classification current sourcing, programmable inrush current limiting via an external gate capacitor, and a complementary open-drain PG (power-good) output for sequencing the downstream converter. Above 20 V input the classification current is shut off to reduce internal dissipation, and an internal undervoltage lockout prevents turn-on below the 802.3af minimum operate voltage.
The architecture combines a precision bandgap reference, current-mode signature generation and a gated low-side MOSFET driver. By driving only the return-side FET, the TPS2370PWR allows the upstream PSE to maintain the PoE pair-to-pair voltage regardless of PD load transients. The 8-pin TSSOP body keeps the thermal path short, and the device is rated for the industrial -40C to +85C operating range required for outdoor and industrial Power-over-Ethernet endpoints.
Typical applications include VoIP telephones, wireless LAN access points, IP security cameras, IoT gateways and industrial sensors that draw their power from the Ethernet cable rather than a separate wall adapter. Placing the TPS2370PWR upstream of a wide-input DC-DC converter is the canonical architecture for any 802.3af-compliant PD.
When designing with this part, ensure the inrush gate capacitor is sized for the downstream bulk capacitance to keep inrush current within the 802.3af limit, and verify the transformer bridge is 802.3af compliant with the required center-tap connection. A TVS diode on VPD is strongly recommended for surge robustness above the 100 V abs-max.
This page synthesizes distributor pricing, same-brand and cross-brand drop-in alternatives, and practical PoE design notes not found on a single manufacturer page.
直接替換替代品，適用於 TPS2370PWR — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： TPS2370PWR （相同外形與佔位） — 差異在於 Operating Temperature Range, Package, Function, Inrush Current Limiting, Standards Compliance.
TPS2370PWRG4
✅ 直接替換📋 參考替代品（不在目錄中）
TPS2370PW
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →TPS2370PWG4
✅ 直接替換聯絡詢價
查看資料表 →TPS2376DDAR
✅ 直接替換📋 參考替代品（不在目錄中）
TPS23753APWR
✅ 直接替換📋 參考替代品（不在目錄中）
TPS2370PWR 最大額定值與電氣特性
| 功能 | IEEE 802.3af PoE Powered Device (PD) Interface Switch |
| Standards Compliance | IEEE 802.3af |
| Number of Channels | 1 |
| 封裝 | 8-pin TSSOP (PW) |
| Maximum Input Voltage (VPD) | 100 V |
| Internal FET Rds(on) | 0.3 ohm |
| Detection Signature Resistance | 24.9 kohm (typical) |
| Classification | Class 0 to Class 4 supported |
| Classification Current Shutoff | Above 20 V input |
| Inrush Current Limiting | Programmable via external gate capacitor |
| 電源良好輸出 | Open-drain, complementary |
| 工作溫度範圍 | -40C to +85C |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant |
TPS2370PWR 腳位配置
| 腳位 1 | GND — Analog ground; tie to system GND plane |
| 腳位 2 | VPD — PoE input voltage from Ethernet bridge (up to 100 V abs max) |
| 腳位 3 | RTN — Return-side output of internal pass FET |
| 腳位 4 | APD — Auxiliary power detect / auxiliary power input |
| 腳位 5 | PG — Power good open-drain output (active low) |
| 腳位 6 | GATE — Gate driver for downstream pass element and inrush programming |
| 腳位 7 | CLASS — Class programming pin (external resistor to APD sets Class 0-4) |
| 腳位 8 | VSS — Substrate/internal ground |
典型應用
TPS2370PWR 適用於 6 應用s: IP Security Cameras, VoIP Telephones, Wireless Access Points, Industrial IoT Gateways, Smart Building Sensors, PoE-Powered LED Lighting.
IP Security Cameras
Why the TPS2370PWR fits IP cameras: IEEE 802.3af compliance delivers up to 12.95 W over a single Cat-5 cable, which is sufficient for camera + IR illuminator + lens heater loads. The internal 0.3 ohm pass-FET keeps conduction loss under 50 mW at typical 200 mA load, leaving more budget for the imager and ISP. How it is used: the part sits between the Ethernet RJ-45 magnetics and the downstream DC-DC, presenting the 24.9 kohm detection signature and Class-2/3 current during PSE handshake. A TVS on VPD clamps outdoor surge events, and the inrush gate capacitor is sized for the bulk capacitance on the DC-DC input to stay within the 802.3af inrush limit during hot-plug events.
推薦
VoIP Telephones
Why the TPS2370PWR fits VoIP phones: a single 802.3af PD interface replaces the wall adapter, simplifying deployment in office wall-plate locations without AC outlets. The 0.3 ohm internal FET and 100 V abs-max VPD rating allow safe operation on cable events while keeping the bill of materials minimal. How it is used: the TPS2370PWR negotiates detection and classification, then enables the downstream isolated DC-DC that powers the DSP and handset audio codec. A PG (power-good) output feeds the host MCU so the software can wait for stable bulk power before booting, preventing boot glitches during PoE mid-span events or switch reboot transients.
推薦
Wireless Access Points
Why the TPS2370PWR fits wireless APs: powering radios and baseband from the Ethernet cable eliminates separate AC adapters and lets installers mount the AP at optimal antenna height. IEEE 802.3af with up to 12.95 W is sufficient for dual-radio 2.4 GHz/5 GHz APs in office deployments. How it is used: the TPS2370PWR is upstream of a wide-input 5 V/3 A DC-DC; its PG output enables the downstream regulator only after 802.3af handshake completes. Classification at Class 3 reserves the full 12.95 W budget from the PSE so the AP can transmit at full RF power without under-voltage events during peak traffic.
推薦
Industrial IoT Gateways
Why the TPS2370PWR fits industrial IoT: the -40C to +85C operating range supports factory-floor and outdoor enclosures, and the 100 V abs-max VPD tolerates long cable runs with elevated common-mode voltage. Combining PoE input with the part's small 8-pin TSSOP keeps the BOM small for space-constrained DIN-rail or panel-mount gateways. How it is used: the TPS2370PWR feeds an isolated or non-isolated DC-DC that powers the gateway MCU and cellular/Ethernet uplinks. An external MOV or TVS on VPD handles plant-side surge events common in industrial environments, while the CLASS pin allows the gateway to be set to Class 1 to advertise reduced power draw.
推薦
Smart Building Sensors
Why the TPS2370PWR fits building sensors: low-power PoE PD operation lets designers combine power and data over a single cable, simplifying install in ceiling and wall locations without AC drops. The part's Class 0-4 classification flexibility is useful for sensors that need different power budgets at different sites. How it is used: the TPS2370PWR is placed in the wall or ceiling plate, presenting the 24.9 kohm signature and class current during PSE handshake, then enabling a small 5 V or 3.3 V DC-DC that powers the sensor MCU and wireless mesh radio. The PG output can be wired to the MCU wake pin so radios only transmit after PoE bulk power is stable.
推薦
PoE-Powered LED Lighting
Why the TPS2370PWR fits PoE lighting: 802.3af classification at 12.95 W is enough to power a high-brightness LED fixture with proper driver electronics, eliminating the need for high-voltage AC wiring at the luminaire. The internal pass-FET replaces a discrete hot-swap circuit, shrinking BOM and improving surge robustness. How it is used: the TPS2370PWR feeds a downstream constant-current LED driver, with PG signaling the host controller that PoE negotiation is complete before enabling dimmable lighting. An optional 0-10 V or DALI control interface can be added to drive the LED brightness from the building management system.
推薦
推薦產品摘要
工程參考資料，適用於 TPS2370PWR — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | TPS2370PWRG4 | TPS2370PW | TPS2370PWG4 | TPS2376DDAR | TPS23753APWR |
|---|---|---|---|---|---|---|
| Package | TSSOP-8 (PW) | TSSOP-8 (PW) - same | TSSOP-8 (PW) - same | TSSOP-8 (PW) - same | SO-PowerPAD-8 (DDA) | TSSOP-20 (PW) - larger |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| IEEE Standard | 802.3af (Type 1) | 802.3af (Type 1) | 802.3af (Type 1) | 802.3af (Type 1) | 802.3at (Type 2) | 802.3af with integrated DC-DC |
| Internal FET Rds(on) | 0.3 ohm | 0.3 ohm | 0.3 ohm | 0.3 ohm | 0.3 ohm | 0.3 ohm |
| Integrated DC-DC Controller | No | No | No | No | No | Yes |
| Detection Signature | 24.9 kohm | 24.9 kohm | 24.9 kohm | 24.9 kohm | 24.9 kohm | 24.9 kohm |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
主要差異化特點
- Fully integrated 802.3af PD interface with internal pass-FET (對比TPS23753APWR (TSSOP-20))
- Lower BOM count than DC-DC-integrated alternatives (對比TPS23753APWR)
- Higher package density than SO-PowerPAD competitors (對比TPS2376DDAR (DDA-8))
設計說明
At 802.3af maximum of 350 mA continuous through the internal 0.3 ohm pass-FET, dissipation is approximately 37 mW, well within the TSSOP-8 thermal limit.Estimated: 0.35 A x 0.35 A x 0.3 ohm = 0.0368 W. For higher-power PoE+ designs above 600 mA where the internal FET is the bottleneck, choose TPS2376DDAR instead.
Place the TPS2370PWR as close as possible to the Ethernet bridge/transformer center-tap to keep the VPD trace short and minimize the loop area for surge and ESD events. The CLASS resistor must be referenced to the APD pin, not to GND, to ensure accurate 802.3af classification. Use a 0.1 uF bypass capacitor as close to the VPD pin as practical, in parallel with a TVS diode rated for cable-discharge transients (e.g. SMAJ58CA or similar).
Do not bypass the inrush gate capacitor on the GATE pin - it programs the maximum inrush current at hot-plug, and omitting it allows uncontrolled charging of the downstream bulk capacitance that violates the 802.3af inrush limit and can trip the PSE. Ensure the auxiliary power detect (APD) voltage divider is correctly sized if used with a wall adapter; wrong levels cause the TPS2370PWR to incorrectly interpret the power source. Avoid pulling VPD above 100 V transiently even during surge events.
Keep the GND and VSS planes solid and tied together at a single star point near the TPS2370PWR, with the high-current return path returning directly to the RTN pin to avoid ground bounce in detection classification. The PG trace can be noisy in noisy PoE systems; route it away from VPD and add a small RC filter if the downstream converter shows spurious reset events.
合規資訊
RoHS3 compliant per DiGi Electronics distributor listing. Industrial operating temperature -40C to +85C only; not AEC-Q100 automotive qualified - choose TPS2370-Q1 variants for automotive PoE.
