製品概要
概要
The PM8800A integrates a standard power over Ethernet (PoE) interface and a current mode PWM controller to simplify the design of the power supply sections of all powered devices.
The PoE interface incorporates all the functions required by the IEEE 802.3af including detection, classification, under-voltage lockout (UVLO) and in-rush current limitation.
PM8800A specifically targets PD with extended power requirement with respect to the limit imposed by the 802.3af standard, embedding a hot-swap MOSFET capable of sustaining twice the current of the 802.3af standard with a programmable DC current limit.
The integrated switching regulator has been designed to work with power either form the Ethernet cable connection or from an external power source such as AC adapter.
The DC-DC section of the PM8800A features a programmable oscillator frequency, soft-start, slope compensation and embeds a voltage output error amplifier allowing use in both isolated and non isolated configuration.
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特徴
- Current mode pulse width modulator
- Thermal shutdown protection
- Programmable soft-start
- Programmable oscillator frequency
- 80% maximum duty cycle with internal slope compensation
- Power good indication
- Supports both isolated and non-isolated applications.
- Programmable DCcurrent limit up to 800 mA
- Programmable classification current
- IEEE 802.3af compliant PD interface
- Integrated 100V, 0. 5Ω, 800mA Hot-Swap MOSFET
- Works with power supplied from Ethernet LAN cables or from local auxiliary sources
- Programmable in-rush current limit
- High voltage start-up bias regulator
- Integrated signature resistor
