Overview
The PM8803C, produced by STMicroelectronics, is a high-efficiency integrated Power over Ethernet (PoE) interface and PWM controller. This component is designed to simplify the power supply sections of powered devices, ensuring compliance with the IEEE 802.3at standard. It integrates all necessary functions for PoE/PoE+ interfaces, including detection, classification, undervoltage lockout (UVLO), and inrush current limitation. The PM8803C can operate with power from either Ethernet LAN cables or from an external auxiliary source, prioritizing the auxiliary source over PoE. It features a programmable oscillator frequency, adjustable slope compensation, and support for various converter topologies such as flyback, forward, and synchronous rectification.
Key Specifications
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| PWM Comparator Delay-to-output | - | 25 | - | ns |
| Minimum Duty Cycle | 0 | - | - | % |
| Maximum Duty Cycle | 75 | 80 | 85 | % |
| CTL to PWM Gain | - | 1 : 4 | - | - |
| CTL Operative Range | 1 | - | 3 | V |
| Output Driver GAT1 Output High | VC-0.25 | VC-0.5 | - | V |
| Output Driver GAT1 Output Low | 0.25 | 0.5 | - | V |
| Fall Time | - | 40 | - | ns |
| Rise Time | - | 45 | - | ns |
| Integrated Hot-swap MOSFET | - | 100 V, 0.45 Ω, 1 A | - | - |
| Inrush Current Level | - | 140 mA | - | - |
Key Features
- IEEE 802.3at compliant PD interface
- Works with power supplied from Ethernet LAN cables or from local auxiliary sources
- Successful IEEE802.3at Layer 1 hardware classification indicator
- Integrated 100 V, 0.45 Ω, 1 A hot-swap MOSFET
- Accurate 140 mA typ. inrush current level
- Programmable classification current and DC current limit up to 1 A
- Integrated high voltage start-up bias regulator
- Thermal shutdown protection
- Current mode pulse width modulator
- Programmable oscillator frequency and adjustable slope compensation
- Support for flyback, forward, forward active clamp, and flyback with synchronous rectification
Applications
- VoIP phones
- WLAN Access Points (AP)
- WiMAX Customer Premises Equipment (CPEs)
- Security cameras
- PoE/PoE+ powered device appliances
Q & A
- What is the PM8803C used for?
The PM8803C is used to integrate a Power over Ethernet (PoE) interface and a current mode PWM controller, simplifying the design of power supply sections in powered devices.
- Is the PM8803C compliant with IEEE 802.3at standards?
Yes, the PM8803C is fully compliant with the IEEE 802.3at standard for PoE/PoE+ interfaces.
- What types of power sources can the PM8803C work with?
The PM8803C can work with power from either Ethernet LAN cables or from an external auxiliary source, such as a wall adapter, prioritizing the auxiliary source.
- What is the maximum duty cycle of the PM8803C?
The maximum duty cycle of the PM8803C is 80% with internal slope compensation.
- Does the PM8803C have thermal protection?
Yes, the PM8803C features thermal shutdown protection to prevent overheating.
- What is the inrush current level of the PM8803C?
The PM8803C has an accurate 140 mA typical inrush current level.
- Can the PM8803C support various converter topologies?
Yes, it supports flyback, forward, forward with active clamp, and flyback with synchronous rectification.
- What is the integrated hot-swap MOSFET specification?
The integrated hot-swap MOSFET is rated at 100 V, 0.45 Ω, and 1 A.
- Is the PM8803C RoHS compliant?
Yes, the PM8803C is RoHS compliant.
- What are some common applications of the PM8803C?
Common applications include VoIP phones, WLAN AP, WiMAX CPEs, security cameras, and other PoE/PoE+ powered devices.
