TPS2370PW - IEEE 802.3af PoE PD Interface, 8-TSSOP | Texas Instruments
MPN： TPS2370PW ✓ 啟用中TPS2370PW 概覽
A PoE PD controller is a specialized power management integrated circuit that handles the front-end handshake between a PoE-enabled switch (PSE) and the device receiving power (PD). It detects a valid 25 kohm signature resistor, classifies the PD into one of five power classes (0-4) under the IEEE 802.3af spec, controls inrush current with a soft-start mechanism, and finally applies power through an integrated low-RDS(on) MOSFET. The TPS2370 occupies the power management IC hierarchy between simple hot-swap controllers and full PoE+ (802.3at) Type 2 controllers, representing the original-generation 802.3af building block.
Key features include a 0.3-ohm internal pass MOSFET, programmable inrush current limiting, integrated detection signature circuitry, automatic classification signature generation, and an open-drain power-good output indicator. The 8-pin TSSOP package enables compact front-end designs for IP phones, wireless access points, and security cameras where PCB real estate is at a premium. The device operates from the 48 V nominal PoE rail but tolerates transients consistent with cable discharge events.
The architecture uses a precision bandgap reference and comparators to implement the IEEE 802.3af detection signature (25 kohm equivalent resistance), and a current-mode control loop for inrush limiting. Once classification completes, the internal 100 V N-channel MOSFET is fully enhanced, minimizing DC losses. Logic-level interfaces provide ground-referred status and enable signals for downstream DC-DC converters.
Typical applications include VoIP phones, wireless access points (Wi-Fi APs), IP security cameras, RFID readers, and any low-power 802.3af-compliant PD that derives its primary supply from a PoE line. Industrial sensors and building automation endpoints also benefit from single-cable power-and-data deployment enabled by this controller.
When designing with this part, follow IEEE 802.3af detection and classification timing budgets closely; bypass the device with a TVS diode for cable discharge protection, and select the input bulk capacitor and inrush timing components per the datasheet's typical application circuit to avoid re-triggering detection during power-up.
This page synthesizes distributor availability, drop-in alternatives to other 8-pin TSSOP PoE PD controllers, and practical layout considerations that go beyond the datasheet's typical application drawings.
直接替換替代品，適用於 TPS2370PW — 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： TPS2370PW （相同外形與佔位） — 差異在於 Package, Operating Temperature Range, Function, Detection Signature, Inrush Current Limiting.
TPS2370PWR
✅ 直接替換聯絡詢價
查看資料表 →TPS2370PWG4
✅ 直接替換聯絡詢價
查看資料表 →TPS2375PW-1
✅ 直接替換聯絡詢價
查看資料表 →TPS23757PWR
✅ 直接替換聯絡詢價
查看資料表 →TPS2370PW 最大額定值與電氣特性
| 功能 | IEEE 802.3af Power Interface Switch for PoE Powered Devices |
| Standards Compliance | IEEE 802.3af (PoE Type 1) |
| Input Voltage Range (VCC) | 0 V to 67 V (operating) |
| Maximum Switch Voltage (VPORT to GND) | 100 V |
| Internal Pass FET RDS(on) | 0.3 ohm |
| Detection Signature | 25 kohm standard (802.3af) |
| Classification Classes | Class 0 through Class 4 |
| Inrush Current Limiting | Programmable via external components |
| 工作溫度範圍 | -40 C to +85 C |
| 封裝 | 8-pin TSSOP (PW) |
| 安裝類型 | Surface Mount |
| MSL 等級 | 1 (unlimited floor life at <30 C / 85 % RH) |
| 電源良好輸出 | Open-drain, active low |
| Enable Logic | Active-high (PG output gates downstream DC/DC) |
| RoHS 狀態 | Compliant |
| Lead-Free Finish | Yes (NiPdAu) |
TPS2370PW 腳位配置
| 腳位 1 | RTN — Return / 25 kohm signature node, bias reference |
| 腳位 2 | DET — Detection capacitor / timing node |
| 腳位 3 | CLS — Classification capacitor node |
| 腳位 4 | GND — Ground |
| 腳位 5 | PG — Power-Good, open-drain output (active low) |
| 腳位 6 | VCC — Switched VCC output to downstream load |
| 腳位 7 | APG — Auxiliary / pass-FET gate control node |
| 腳位 8 | VPORT — Port voltage input from Ethernet cable |
典型應用
TPS2370PW 適用於 6 應用s: VoIP Phone / IP Desk Phone, Wireless Access Point (Wi-Fi AP / AP), IP Security Camera (PoE IP Camera), Industrial Sensor / Building Automation Node, RFID Reader / Access Control Reader, Low-Power IoT Gateway / Edge Node.
VoIP Phone / IP Desk Phone
The TPS2370PW is the canonical front-end controller for IEEE 802.3af-powered VoIP desk phones. With its integrated 0.3-ohm FET and built-in detection/classification engines, it eliminates the need for a discrete hot-swap MOSFET and shrinks the front-end footprint to a few square centimeters - critical for the slim base of an enterprise IP phone. The 100 V switch rating absorbs cable discharge events during PoE cable insertion, and the 8-pin TSSOP layout fits directly behind the RJ-45 jack. Combined with an isolated buck converter downstream (for example TPS54331), the TPS2370PW enables a single Ethernet cable to supply +5 V at 5 W to the phone's codec and MCU with no AC adapter required.
推薦
Wireless Access Point (Wi-Fi AP / AP)
Enterprise 802.11ax and outdoor mesh Wi-Fi access points are routinely powered by 802.3af PoE, and the TPS2370PW is well suited to this role. Its integrated 0.3-ohm pass FET sustains Class 3 (12.95 W) PD current at the -40 C to +85 C operating range, while its compact TSSOP-8 footprint leaves more board area for the radio module. The open-drain PG output signals downstream regulators to soft-start their outputs, avoiding inrush-related resets on the AP's processor. By placing the TPS2370PW between the Ethernet magnetics and the AP's main 3.3 V / 1.8 V buck regulators, designers achieve a fully standards-compliant PoE PD that interoperates with Cisco, Aruba, and other vendor PSEs.
推薦
IP Security Camera (PoE IP Camera)
Wired IP surveillance cameras in buildings and outdoor installations rely on the TPS2370PW for IEEE 802.3af front-end compliance. The part accepts the 48 V PoE rail, performs detection/classification handshake, and switches the load through its 0.3-ohm FET with programmable inrush limiting to avoid tripping upstream PSE current limits. Its TSSOP-8 footprint enables a thin camera base, and the -40 C to +85 C rating supports outdoor enclosures. In a typical design, the TPS2370PW feeds a wide-input isolated or non-isolated DC-DC (for example LM5163) that produces 12 V or 5 V for the image sensor, ISP, and PoE-powered IR illuminator, all powered from a single CAT5e/CAT6 cable.
推薦
Industrial Sensor / Building Automation Node
Building-automation and industrial sensors (temperature, CO2, occupancy, leak detection) are increasingly deployed as PoE-powered nodes. The TPS2370PW handles the full 802.3af handshake, including 25 kohm signature and Class 0-4 classification, while its industrial temperature rating (-40 C to +85 C) suits factory floor and rooftop environments. Its small TSSOP-8 package allows it to be embedded inside RJ-45 wall plates or small DIN-rail enclosures. The PG output can be wired to a downstream MCU's enable pin to power up the sensor and MCU rail only when PoE is present, minimizing standby power in permanently-installed nodes.
推薦
RFID Reader / Access Control Reader
Multi-frequency RFID readers and PoE-powered door access terminals benefit from the TPS2370PW's compact 8-pin TSSOP front end. Its integrated detection-class-inrush-switch-FET chain simplifies the receiver's power architecture: power comes from a single CAT6 cable run, and the TPS2370PW's low RDS(on) (0.3 ohm) keeps continuous losses low even at sustained read current. The PG output synchronizes startup of the RFID modulator and the door-strike relay driver. Designs typically pair the TPS2370PW with an isolated flyback or forward converter providing 12 V for the RFID coil driver and 5 V for the access-control logic.
推薦
Low-Power IoT Gateway / Edge Node
Low-power IoT gateways and protocol converters (for example BACnet, Modbus, or LoRaWAN bridges) are commonly installed at locations without dedicated AC mains, making PoE attractive. The TPS2370PW serves as the front-end interface for these gateways, accepting the 48 V PoE input, performing Class 0-4 classification, and switching power through its 0.3-ohm pass FET. Its TSSOP-8 footprint fits inside compact wall-plate enclosures, and its open-drain PG output can trigger the downstream STM32F030 MCU and SX127x LoRa transceiver to start up only when valid PoE is present, ensuring deterministic cold-boot behavior in field deployments.
推薦
推薦產品摘要
工程參考資料，適用於 TPS2370PW — 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 | TPS2370PWR | TPS2370PWG4 | TPS2375PW |
|---|---|---|---|---|
| Package | 8-TSSOP (PW) | 8-TSSOP (PW) - same | 8-TSSOP (PW) - same | 8-TSSOP (PW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| PoE Standard | IEEE 802.3af (Type 1) | IEEE 802.3af (Type 1) | IEEE 802.3af (Type 1) | IEEE 802.3af (Type 1) |
| Classification Classes | Class 0-4 | Class 0-4 | Class 0-4 | Class 0-4 |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| Packaging Code | PW (Tube) | PWR (Tape & Reel) | PWG4 (Tube, RoHS) | PW (Tube) |
主要差異化特點
- Lowest-cost 802.3af-only PD controller in TSSOP-8 (對比TPS2376 / TPS23757 (802.3at parts))
- Integrated 0.3-ohm pass FET removes external MOSFET (對比Discrete hot-swap FET + separate PD controller)
- Drop-in same-package variants exist (TPS2370PWR, PWG4) for supply flexibility (對比TPS2375PW (different timing pinout))
設計說明
PoE front-end designs must include a TVS diode from VPORT to GND (typically 58 V SMBJ type) to absorb IEEE 802.3af cable discharge events of up to 1000 V. The TPS2370PW's 100 V internal switch rating survives a single such event but does not substitute for proper line-side TVS protection. Place the TVS within 5 mm of the RJ-45 connector; keep the high-current return path short and away from the RTN pin to avoid disturbing the 25 kohm detection signature.
At Class 3 continuous load (12.95 W / 48 V = 270 mA), the internal 0.3-ohm FET dissipates approximately P = I^2 x R = 22 mW - well within the TSSOP-8 thermal budget. However, during inrush into a pre-charged bulk capacitor, peak currents up to 800 mA can occur briefly. Ensure the inrush RC network is sized so that dV/dt produces currents inside the TPS2370PW's safe-limit envelope; consult the datasheet's inrush diagram for the recommended external components.
Estimated: at 48 V input and 12.95 W output the steady-state power dissipation in the TPS2370PW remains under 25 mW, so no thermal copper pour is required. However, the high-voltage 48 V trace from the RJ-45 to pin 8 (VPORT) should still be widened to 0.5 mm or more and spaced away from low-voltage digital traces by at least 1.5 mm per IPC-2221B creepage for 60 V working voltage. Place the detection-class timing capacitor directly adjacent to the DET and CLS pins; keep its ground return short to pin 4 (GND) to avoid corrupting the 25 kohm signature measurement.
合規資訊
RoHS and lead-free per TI datasheet top marking; AEC-Q100 not applicable - this is not an automotive part, but the TPS2370 family has been used in some industrial-grade designs.
