PM8801 datasheet(31/37 Pages) STMICROELECTRONICS

Il numero della parte	PM8801

Spiegazioni elettronici	High-efficiency, IEEE 802.3at compliant, integrated PoE-PD interface and PWM controller

PDF	37 Pages

Scroll/Zoom	100%

Produttore elettronici	STMICROELECTRONICS [STMicroelectronics]

Homepage	http://www.st.com

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31 / 37 page

DocID018560 Rev 2

31/37

PM8801

PWM controller

When a severe overcurrent occurs, like a short-circuit of an internal power component, and

0.7 V level is reached on CS, the gate driver is instantaneously shut down and a new soft-

start is performed after 4096 switching periods.

In case of persistent severe overcurrent, the control logic tries 4 cycles of fast hiccup before

completely shutting down the PWM controller.

To restart the device, after removing the cause of the overcurrent, VDD must be reduced

below the UVLO level.

Figure 16. Overload (left) and short-circuit (right) behavior

Ch1: CTL signal, Ch2: 5Vout, Ch3: I input

5.6

Thermal protection

The PM8801 thermal protection limit is set to 160 °C on the junction temperature and is

always active. When this threshold is exceeded, the hot-swap MOSFET is opened and the

PWM controller is switched off.

When the junction temperature goes below about 130 °C the converter will start

automatically, without needing to recycle the input voltage.

PM8801 Scheda tecnica(PDF) 31 Page - STMicroelectronics