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)

45V

BST to GND

60V

PRE to GND

45V

SW to GND (Steady State)

-1.5V

45V

14V

BST to SW

14V

OUT to GND

Limited to Vin

SD, SYNC, SS, FB to GND

7V

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 1.5k

Ω resistor into each pin.

Operating Ratings

(1)

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 .

Copyright © 2006–2013, Texas Instruments Incorporated

Submit Documentation Feedback

3

Product Folder Links: LM25005