4-Port PoE Manager

Microsemi Proprietary and Confidential. PD69104B1/F Datasheet Revision 2.0

5

event voltages to the ports, as required by the IEEE standard.

3.5

Current Limiter

This circuit continuously monitors the current of the powered ports and limits it to a specific value,

according to predefined limits set using the Current_Set pin. In case the current exceeds this specific

level, the system starts measuring the elapsed time. If this period is longer than the preset threshold,

the port is disconnected.

3.6

Main MOSFET

Main power switching FET is used for controlling the PoE current that streams into the load.

3.7

IC and Port Parameters Monitoring

A 10-bit analog-to-digital converter is used for converting analog signals into digital registers.

IC main voltage monitoring—The chip main voltage is sampled every 1 mS. Each measurement is an

average of four consecutive ADC measurements and stored in the relevant register. The main

voltage measurement resolution is 5.835 mV/count ±5%.

IC thermal monitoring—The PD69104B1/F contains a thermal sensor that is sampled to register

every 1 mS so the PD69104B1/F die temperature can be monitored at all time.

Port current/voltage monitoring—After the ports start to deliver the power the current/voltage is

sampled every 1 mS on each port. Each measurement is an average of four consecutive ADC

measurements and stored in the relevant register. Current measurement resolution is 122.07 µA

/count ±5% and voltage measurement resolution is 5.835 mV/count ±5% (refer to the PD69104B1/F

User Guide register map document for more details).

3.8

Power-on Reset (PoR)

This element monitors the internal 3.3 V levels. If this voltage drops below specific thresholds, a reset

DC

signal is generated and the PD69104B1/F is reset.

3.9

Voltage Regulator

The voltage regulator generates 3.3 V and 5 V for the internal circuitry. These voltages are derived

DC

DC

from the V

supply.

main

3.10

Clock (CLK)

This is an internal 8 MHz CLK oscillator.

3.11

I²C Address Selection

The following table lists the I2C address selection for the PD69104B1/F device.

Table 1 • I2C Address Selection

CONST

Bits

ADDR3

Slave 1 Bit

ADDR2

Slave 0 Bit

ADDR1

ID1 Bit

ADDR0

ID0 Bit

I²C/UART Address

0 1 0

0

0

0

0

0100000b

0 1 0

0

0

0

1

0100001b

0 1 0

0

0

1

0

0100010b

0 1 0

0

0

1

1

0100011b

0 1 0

0

1

0

0

0100100b

0 1 0

0

1

0

1

0100101b

0 1 0

0

1

1

0

0100110b

0 1 0

0

1

1

1

0100111b

0 1 0

1

0

0

0

0101000b