ltc4264cde-trpbf Linear Technology Corporation, ltc4264cde-trpbf Datasheet - Page 5

• Manufacturer Part Number: ltc4264cde-trpbf
• Description: High Power Pd Interface Controller With 750ma Current Limit
• Manufacturer: Linear Technology Corporation

PIN FUNCTIONS
SHDN (Pin 1): Shutdown Input. Used to command the
LTC4264 to present an invalid signature. Connecting
SHDN to GND lowers the signature resistance to an invalid
value and disables other LTC4264 operations. If unused,
tie SHDN to V
NC (Pin 2): No Internal Connection.
R
the LTC4264 maintains during classifi cation. Connect a
resistor between R
I
LTC4264 current limit behavior during powered operation.
For normal operation, fl oat I
current. Tie I
Note that the inrush current limit does not change with
I
V
the diode bridge. Pins 5 and 6 must be electrically tied
together.
V
PD load through the internal power MOSFET. V
impedance until the input voltage rises above the UVLO
turn-on threshold. The output is then connected to V
through a current-limited internal MOSFET switch. Pins 7
and 8 must be electrically tied together.
LIM_EN
LIM_EN
IN
OUT
CLASS
(Pins 5, 6): Power Input. Tie to the PD input through
(Pins 7, 8): Power Output. Supplies power to the
(Pin 4): Input Current Limit Enable. Used to control
(Pin 3): Class Select Input. Used to set the current
selection. See Applications Information.
LIM_EN
IN
.
CLASS
to V
IN
and V
to disable input current limit.
LIM_EN
IN
. (See Table 2.)
to enable I
OUT
LIMIT_HIGH
is high
IN
PWRGD (Pin 9): Active High Power Good Output, Open
Collector. Signals to the DC/DC converter that the LTC4264
MOSFET is on and that the converter can start operation.
High impedance indicates power is good. PWRGD is ref-
erenced to V
in the event of a thermal overload. PWRGD is clamped
14V above V
PWRGD (Pin 10): Active Low Power Good Output, Open-
Drain. Signals to the DC/DC converter that the LTC4264
MOSFET is on and that the converter can start operation.
Low impedance indicates power is good. PWRGD is
referenced to V
tion, classifi cation and in the event of a thermal overload.
PWRGD has no internal clamps.
NC (Pin11): No Internal Connection.
GND (Pin 12): Ground. Tie to system ground and power
return through the input diode bridge.
Exposed Pad (Pin 13): Must be soldered to electrically
isolated heat sink.
OUT
OUT
IN
.
and is low impedance during inrush and
and is high impedance during detec-
LTC4264
5
4264f