NCP1091DBG - PoE-PD 802.3af Interface Controller | onsemi
料号： NCP1091DBG ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.32 | $132.00 |
| 500 | $1.12 | $560.00 |
| 1,000 | $0.95 | $950.00 |
NCP1091DBG 概述
A PoE-PD interface controller is the front-end circuit inside any powered device (such as an IP camera, wireless access point, or VoIP phone) that draws power over Ethernet cabling. Within the power-management hierarchy, it sits between the Ethernet magnetics/diode bridge and the downstream DC-DC converter, handling the detection, classification, and inrush-control handshake that IEEE 802.3af requires before full power is granted.
Key features of the NCP1091 include the complete IEEE 802.3af signature functions: powered-device detection, classification, and under-voltage lockout (UVLO). It also provides programmable inrush and operational current limit, plus a power-good signal that guarantees clean enable and disable sequencing of the downstream DC-DC controller. The distinguishing feature versus the NCP1090 is its programmable under-voltage lockout threshold, letting designers tailor the brown-out point to their converter topology.
Technically, the NCP1091 integrates a precision detection and classification front end with a pass-element control loop that limits inrush current during PSE capacitor charging, then transitions to operational current limiting during normal running. The power-good output only asserts when the PoE rail is valid, preventing premature startup of the isolated or non-isolated converter and protecting against IEEE-compliance violations.
Typical applications include IP surveillance cameras, 802.3af-compliant wireless access points, VoIP and SIP desk phones, and any Ethernet-fed sensor or industrial endpoint that must present a valid PoE signature to the power-sourcing equipment.
A key design consideration: verify the classification resistor setting and programmable UVLO divider against the maximum cable power budget, since the class advertised must match the load drawn after the DC-DC converter.
This page synthesizes distributor availability data, family-level substitution analysis, and practical design notes not found in a single manufacturer datasheet.
直接替换替代料： NCP1091DBG ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
NCP1090
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
NCP1092
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
NCP1091D
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
NCP1091DBG 规格参数
| 功能 | IEEE 802.3af PoE Powered Device (PD) interface controller |
| 通道数 | 1 |
| Input Voltage (max) | 57 V |
| Supply/Pass Current Capability | 500 mA |
| PoE Standard | IEEE 802.3af |
| Detection | Yes (PD signature detection) |
| Classification | Yes (802.3af class) |
| UVLO | Yes, programmable |
| Inrush Current Limit | Yes, programmable |
| Operational Current Limit | Yes |
| 电源正常输出 | Yes |
| 封装 | TSSOP-8 |
| Pins | 8 |
| 安装类型 | Surface Mount |
| Family | onsemi HIPO PoE-PD (NCP1090/NCP1091/NCP1092) |
NCP1091DBG tssop-8 引脚配置指南
NCP1091DBG（tssop-8 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： NCP1091DBG.
请参阅 数据手册 以查看完整引脚配置。
典型应用
NCP1091DBG 适用于 6 应用s: IP Surveillance Cameras, Wireless Access Points, VoIP and SIP Desk Phones, Industrial Ethernet Endpoint Sensors, Building Automation and Door Controllers, Networked Audio Endpoints.
IP Surveillance Cameras
IP cameras are the archetypal IEEE 802.3af powered device: a single Cat5e cable delivers both video data and up to 12.95W of class-guaranteed power. The NCP1091DBG fits because its 57V input rating and 500mA capability cover the 802.3af rail, and its detection and classification logic presents a valid signature to the PSE while the camera's imaging SoC is still off. The power-good output then releases the camera's DC-DC converter only after inrush charging completes, avoiding signature corruption. The programmable UVLO lets designers raise the turn-on threshold so night-vision IR LED bursts do not drag the bus below the converter's valid input range, improving brown-out robustness on long cable runs.
推荐
Wireless Access Points
802.11ax/ba wireless access points are frequently fed from PoE switches using the 802.3af budget. The NCP1091DBG provides the required PD front end: signature detection, class advertisement, and controlled inrush so the radio SoC's bulk input capacitance does not violate IEEE timing. Its 57V rating handles the maximum PSE open-circuit voltage, and 500mA capability supports class-appropriate loads. The power-good output sequences the Wi-Fi rail cleanly, preventing RF spurs during startup. With programmable UVLO, designers can align the enable threshold with the access point's peak transmit current profile, avoiding converter reset during burst transmissions when cable DC resistance drops the PD input voltage toward the lockout region.
推荐
VoIP and SIP Desk Phones
Enterprise VoIP phones must draw power from the same Ethernet cable used for voice traffic, making an IEEE 802.3af PD interface mandatory. The NCP1091DBG integrates all required handshake functions - detection, classification, under-voltage lockout, and both inrush and operational current limiting - in a single 8-pin TSSOP, saving board area in the phone's constrained base. The power-good signal gates the phone's audio codec and processor converters so no current flows during detection, preserving IEEE compliance. Its programmable UVLO is useful for phones with speakerphone amplifiers whose peak current demands a higher, custom brown-out point than the IEEE minimum, protecting against audio dropouts on marginal switch ports.
推荐
Industrial Ethernet Endpoint Sensors
Factory-floor sensors on industrial Ethernet infrastructure increasingly use PoE to eliminate separate power wiring. The NCP1091DBG's 57V tolerance suits long cable runs where DC resistance and transient events depress or spike the delivered rail, while its operational current limit protects the PD electronics against fault conditions on noisy industrial networks. Detection and classification circuits present a valid IEEE signature so enterprise-grade PoE switches recognize the endpoint. The power-good output provides a clean sequencing edge to the sensor's microcontroller and analog front-end converters. Programmable UVLO helps designers accommodate legacy switch ports that deliver rail voltages below the nominal 48V, ensuring reliable startup across mixed PoE infrastructure.
推荐
Building Automation and Door Controllers
Door access controllers, occupancy sensors, and HVAC edge controllers often mount in ceilings or corridors where only Ethernet cabling exists. The NCP1091DBG converts such infrastructure into a powered device: its detection/classification handshake negotiates power from the PoE switch, and its programmable inrush limit safely charges the controller's bulk capacitance. The 57V maximum input covers surge conditions on structured cabling shared with elevator and motor equipment, and the power-good output sequences the controller's logic rails so relays do not chatter during power-up. With 500mA capability, the part supports controller electronics plus relay drivers within an 802.3af class budget, and programmable UVLO aligns startup with lock-type actuator current profiles.
推荐
Networked Audio Endpoints
PoE-fed speakers, paging horns, and conference-room audio endpoints benefit from the NCP1091DBG's clean power sequencing: the power-good output keeps audio amplifiers disabled until the PoE rail is fully valid, eliminating power-on pops in distributed audio systems. The part's detection and classification circuits negotiate an 802.3af class budget appropriate to the amplifier's continuous power draw, while operational current limiting protects against shorted speaker lines. Its programmable UVLO can be set above the amplifier's minimum supply so audio output mutes gracefully during brown-out rather than generating distortion. The compact 8-pin TSSOP fits within the endpoint's amplifier PCB area without complicating layout of the analog section.
推荐
推荐产品汇总
工程参考数据： NCP1091DBG ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | NCP1090 | NCP1092 | NCP1091D |
|---|---|---|---|---|
| Package | TSSOP-8 | TSSOP-8 - same | TSSOP-8 - same | TSSOP-8 - same |
| Brand | onsemi | onsemi | onsemi | onsemi |
| PoE Standard | IEEE 802.3af | IEEE 802.3af | IEEE 802.3af | IEEE 802.3af |
| Max Input Voltage | 57 V | 57 V (family rating) | 57 V (family rating) | 57 V |
| UVLO | Programmable | Fixed | Fixed | Programmable |
| Auxiliary Supply Pin | No | No | Yes | No |
| Power Good Output | Yes | Yes | Yes | Yes |
关键差异点
- Programmable UVLO threshold （对比 NCP1090)
- Minimal 8-pin footprint without auxiliary complexity （对比 NCP1092)
- Integrated power-good sequencing （对比 NCP1090)
设计说明
Gate the downstream DC-DC converter with the NCP1091 power-good output. During IEEE 802.3af detection and classification, the PD must present a clean 25 kOhm signature; any converter leakage current corrupts detection and the PSE will deny power. Enable the converter only after the power-good signal asserts, and size the input bulk capacitor so the programmable inrush limit can charge it within the IEEE timing window - excessive capacitance combined with a low inrush setting causes startup faults that look like intermittent PSE reconnects.
The DBG suffix denotes onsemi's Pb-free/RoHS packaging variant; ordering the wrong suffix can deliver a tape-and-reel or grade variant with different packing but the same silicon. When setting the programmable UVLO divider, account for the input diode bridge drop and cable DC resistance: the divider senses the DC-DC input rail, not the PSE output. A threshold set too high causes reset cycling on 100 m cable runs; set it only as high as the converter actually requires.
Keep the loop from the Ethernet diode bridge through the NCP1091 pass-element control to the bulk capacitor short and wide, since inrush events push the full rail current through this path. Place the classification and UVLO divider resistors away from the pass-node copper to prevent voltage-sensing errors during classification timing windows. Provide a low-impedance ground connection between VSS and the bridge return, and follow the NCP1091 datasheet layout example for the 8-pin TSSOP thermal and current paths.
合规信息
The DBG suffix conventionally denotes onsemi Pb-free/RoHS-conformant packaging; formal RoHS/REACH declarations were not present in the verified web data and should be confirmed on the onsemi product page.
