Datasheet

LM25005
www.ti.com SNVS411C –JANUARY 2006–REVISED MARCH 2013
PIN DESCRIPTIONS (continued)
Pin(S) Name Description Application Information
Current measurement connection for the re-circulating diode. An
internal sense resistor and a sample/hold circuit sense the diode
15, 16 IS Current sense current near the conclusion of the off-time. This current
measurement provides the DC level of the emulated current
ramp.
The source terminal of the internal buck switch. The SW pin
17, 18 SW Switching node should be connected to the external Schottky diode and to the
buck inductor.
This open drain output can be connected to SW pin to aid
charging the bootstrap capacitor during very light load conditions
Pre-charge assist for the bootstrap or in applications where the output may be pre-charged before
19 PRE
capacitor the LM25005 is enabled. An internal pre-charge MOSFET is
turned on for 250ns each cycle just prior to the on-time interval
of the buck switch.
An external capacitor is required between the BST and the SW
pins. A 0.022µF ceramic capacitor is recommended. The
20 BST Boost input for bootstrap capacitor
capacitor is charged from Vcc via an internal diode during the
off-time of the buck switch.
Exposed metal pad on the underside of the device. It is
NA EP Exposed Pad recommended to connect this pad to the PWB ground plane, in
order to aid in heat dissipation.
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings
(1)(2)
V
IN
to GND 45V
BST to GND 60V
PRE to GND 45V
SW to GND (Steady State) -1.5V
BST to V
CC
45V
V
CC
to GND 14V
BST to SW 14V
OUT to GND Limited to Vin
SD, SYNC, SS, FB to GND 7V
ESD Rating
(3)
Human Body Model 2kV
Storage Temperature Range -65°C to +150°C
(1) Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which
operation of the device is intended to be functional. For ensured specifications and test conditions, see the Electrical Characteristics .
(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and
specifications.
(3) The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin.
Operating Ratings
(1)
V
IN
7V to 42V
Operation Junction Temperature −40°C to + 125°C
(1) Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which
operation of the device is intended to be functional. For ensured specifications and test conditions, see the Electrical Characteristics .
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