LTC4267IGN-1-PBF datasheet(8/32 Pages) LINER

8 / 32 page

LTC4267-1

42671f

PI FU CTIO S

PGND (Pin 1, 8, 9, 16): Switching Regulator Negative

Supply. This pin is the negative supply rail for the switching

regulator controller and must be tied to POUT.

ITH/RUN (Pin 2): Current Threshold/Run Input. This

pin performs two functions. It serves as the switching

regulator error ampliﬁer compensation point as well as

the run/shutdown control input. Nominal voltage range is

0.7V to 1.9V. Forcing the pin below 0.28V with respect to

PGND causes the controller to shut down.

NGATE (Pin 3): Gate Driver Output. This pin drives the

regulator’s external N-Channel MOSFET and swings from

PGND to PVCC.

PVCC (Pin 4): Switching Regulator Positive Supply. This

pin is the positive supply rail for the switching regulator

and must be closely decoupled to PGND.

RCLASS (Pin 5): Class Select Input. Used to set the current

value the PD maintains during classiﬁcation. Connect a

resistor between RCLASS and VPORTN (see Table 2).

NC (Pin 6): No Internal Connection.

VPORTN (Pin 7): Negative Power Input. Tie to the –48V

input port through the input diodes.

POUT (Pin 10):Power Output. Supplies –48V to the switch-

ing regulator PGND pin and any additional PD loads through

an internal power MOSFET that limits input current. POUT

is high impedance until the voltage reaches the turn-on

UVLO threshold. The output is then current limited. See

the Application Information section.

⎯P⎯W⎯R⎯G⎯D (Pin 11): Power Good Output, Open-Drain.

Indicates that the PD MOSFET is on and the switching

regulator can start operation. Low impedance indicates

power is good.

⎯P⎯W⎯R⎯G⎯D is high impedance during detec-

tion, classiﬁcation and in the event of a thermal overload.

⎯P⎯W⎯R⎯G⎯D is referenced to V

PORTN.

SIGDISA (Pin 12): Signature Disable Input. SIGDISA al-

lows the PD to present an invalid signature resistance and

remain inactive. Connecting SIGDISA to VPORTP lowers

the signature resistance to an invalid value and disables

all functions of the LTC4267-1. If unused, tie SIGDISA to

VPORTN.

VPORTP (Pin 13): Positive Power Input. Tie to the input

port power return through the input diodes.

SENSE (Pin 14): Current Sense. This pin performs two

functions. It monitors the regulator switch current by read-

ing the voltage across an external sense resistor. It also

injects a current ramp that develops a slope compensation

voltage across an optional external programming resistor.

See the Applications Information section.

VFB(Pin15):FeedbackInput.Receivesthefeedbackvoltage

from the external resistor divider across the output.

LTC4267IGN-1-PBF 数据表(PDF) 8 Page - Linear Technology

LTC4267IGN-1-PBF 数据表(HTML) 8 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

数据表下载