Overview
The PM8803, produced by STMicroelectronics, is a high-efficiency integrated Power over Ethernet (PoE) interface and current mode PWM controller. This component is designed to simplify the power supply sections of powered devices, ensuring compliance with IEEE 802.3at standards. It integrates all necessary functions for PoE/PoE+ interfaces, including detection, classification, undervoltage lockout (UVLO), and inrush current limitation. The PM8803 can operate with power from either Ethernet LAN cables or external auxiliary sources, prioritizing the auxiliary source over PoE. It supports various converter topologies such as flyback, forward, forward with active clamp, and synchronous rectification, ensuring high-efficiency conversion under all load conditions.
Key Specifications
| Parameter | Test Conditions | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|---|
| Signature pull-down resistance | Within signature range | 150 | 350 | Ω | |
| Classification turn-off | VDD rising | 21.5 | 23.0 | 24.5 | V |
| CLS voltage | Within classification range with 44 mA | 0.44 | 0.50 | 0.56 | V |
| Maximum duty cycle | CTL = 2 V, CS = 0, FOSC = 250 kHz | 75 | 80 | 85 | % |
| Hot-swap MOSFET RDS(on) | 0.45 | Ω | |||
| Inrush current limit | 125 | 140 | 155 | mA | |
| Operating Temperature (°C) | -40 | 85 | °C | ||
| Maximum Junction Temperature | 150 | °C |
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 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 with active clamp, and 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 PM8803 and what does it integrate?
The PM8803 integrates a Power over Ethernet (PoE) interface and a current mode PWM controller to simplify the design of the power supply sections of powered devices.
- Is the PM8803 compliant with IEEE 802.3at standards?
- What types of power sources can the PM8803 work with?
The PM8803 can work with power from either Ethernet LAN cables or external auxiliary sources, prioritizing the auxiliary source over PoE.
- What is the maximum duty cycle of the PM8803?
The maximum duty cycle of the PM8803 is 80% with internal slope compensation.
- What is the typical inrush current level of the PM8803?
The typical inrush current level of the PM8803 is 140 mA.
- Does the PM8803 support various converter topologies?
- What is the maximum junction temperature of the PM8803?
The maximum junction temperature of the PM8803 is 150°C.
- Does the PM8803 have thermal shutdown protection?
- What are some common applications of the PM8803?
- What is the package type of the PM8803?
The PM8803 is available in HTSSOP20 package.
