LTC1921

5

1921f

is compared to the valid supply voltage window and the

result is output at OUT A (Pin 5). Supply current is drawn

FUSE A (Pin 2): This pin monitors the state of a fuse by

(Pin 1). The result is output at OUT F (Pin 4).

RTN (Pin 3): Supply Return Reference. This pin must be

at an equal or higher potential than the other pins and

should be wired to the – 48V return.

OUT F (Pin 4): This pin indicates the state of the external

fuses by ORing the comparisons made to the FUSE A and

exhibit a high internal impedance to the RTN pin. If

internally to the RTN pin and can shunt enough current to

turn off an optoisolator or LED wired between these pins.

OUT F should be clamped externally so that it cannot be

driven more than 8V below RTN. This is done automati-

cally by the optoisolator or LED diodes shown in the

application circuits.

specified voltage window (neither undervoltage nor over-

voltage), OUT A will exhibit a high internal impedance to the

undervoltage limits, then OUT A is shorted internally to the

OUT F pin and can shunt enough current to turn off an

optoisolatoror LED wired between these pins. OUT A should

be clamped externally so that it cannot be driven more than

8V below RTN. This is done automatically by the

optoisolator or LED diodes shown in the application circuits.

specified voltage window (neither undervoltage nor over-

voltage), OUT B will exhibit a high internal impedance to the

undervoltage limits, then OUT B is shorted internally to the

OUT A pin and can shunt enough current to turn off an

optoisolatoror LED wired between these pins. OUT B should

be clamped externally so that it cannot be driven more than

8V below RTN. This is done automatically by the

optoisolator or LED diodes shown in the application circuits.

FUSE B (Pin 7): This pin monitors the state of a fuse by

(Pin 8). The result is output at OUT F (Pin 4).

is compared to the valid supply voltage window and the

result is output at OUT B (Pin 6). Supply current is drawn

PI FU CTIO S