LT4321

5

4321f

For more information www.linear.com/LT4321

pin FuncTions

IN12: Data Pair Input 1. In a PoE system, IN12 connects

to the center tap of the transformer connected to pins 1

and 2 on an RJ45 connector.

IN36: Data Pair Input 2. In a PoE system, IN36 connects

to the center tap of the transformer connected to pins 3

and 6 on an RJ45 connector.

IN45: Spare Pair Input 1. In a PoE system, IN45 connects

to the center tap of the transformer connected to pins 4

and 5 on an RJ45 connector.

IN78: Spare Pair Input 2. In a PoE system, IN78 connects

to the center tap of the transformer connected to pins 7

and 8 on an RJ45 connector.

TG12: Top-Side Gate Driver Output. TG12 pin pulls high

with respect to IN12 when IN12 is greater than OUTP and

IN36 is less than OUTN.

TG36: Top-Side Gate Driver Output. TG36 pin pulls high

with respect to IN36 when IN36 is greater than OUTP and

IN12 is less than OUTN.

TG45: Top-Side Gate Driver Output. TG45 pin pulls high

with respect to IN45 when IN45 is greater than OUTP and

IN78 is less than OUTN.

TG78: Top-Side Gate Driver Output. TG78 pin pulls high

with respect to IN78 when IN78 is greater than OUTP and

IN45 is less than OUTN.

BG12: Bottom-Side Gate Driver Output. BG12 pin pulls

highwithrespecttoOUTNwhenIN36isgreaterthanOUTP

and IN12 is less than OUTN.

BG36: Bottom-Side Gate Driver Output. BG36 pin pulls

highwithrespecttoOUTNwhenIN12isgreaterthanOUTP

and IN36 is less than OUTN.

BG45: Bottom-Side Gate Driver Output. BG45 pin pulls

highwithrespecttoOUTNwhenIN78isgreaterthanOUTP

and IN45 is less than OUTN.

BG78: Bottom-Side Gate Driver Output. BG78 pin pulls

highwithrespecttoOUTNwhenIN45isgreaterthanOUTP

and IN78 is less than OUTN.

EN: Enable, Active Low. Pull down to OUTN to enable ideal

Tie to OUTP if the application circuit uses the EN pin to

enable ideal bridge mode.

EN: Enable, Active High. Pull up to enable ideal diode

bridge mode. EN is internally pulled down to OUTN. Tie

to OUTN if the application circuit uses the EN pin to enable

ideal bridge mode.

OUTP: Positive Output Voltage. OUTP is the rectified

voltage from which the LT4321 draws power.

OUTN: Negative Output Voltage. OUTN is the negative

rectified voltage.

EXPOSED PAD: The exposed pad must be electrically

connected to the OUTN pin.