LM3550SPXSLASHNOPB datasheet(37/43 Pages) TI2

37 / 43 page

LM3550

www.ti.com

SNVS569C – MAY 2009 – REVISED OCTOBER 2016

Product Folder Links: LM3550

Submit Documentation Feedback

11 Device and Documentation Support

11.1 Device Support

11.1.1 Third-Party Products Disclaimer

TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT

CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES

OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER

ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE.

11.1.2 Device Nomenclature

VBATT

Voltage supplying charger circuit.

VCAP

Super-capacitor voltage at the end of the charge cycle and before a flash.

ICL

Maximum current allowed to be drawn from the battery.

IFLASH

LED current during the flash event.

tFLASH

Desired flash duration.

CSC

Super capacitor value.

VLED

Flash diode forward voltage at IFLASH.

VHR

The headroom required across the FET and the Sense resistor to maintain current sink regulation.

VFB

The degeneration resistor RSENSE regulation voltage that in part sets IFLASH.

RDSON

On-Resistance of NFET.

VRDSON

The voltage drop across the current source FET.

VPUMP

The initial SC voltage required for the Flash.

RSENSE

Current set resistor.

VDROOP

Voltage droop on the super-capacitor during a flash of duration tFLASH.

= IFLASH×tFLASH / CSC

RESR

Super-capacitor ESR value.

VESR

Voltage drop due to SC ESR.

VBAL

Voltage drop due to LED ballast resistors

VOH

Overhead charge voltage required for constant current regulation during the entire flash duration.

VPUMP

VOH + VLED+ VESR = VFB + VRDSON + VESR + VLED + VDROOP + VBAL

VHR

VFB + VRDSON

11.2 Related Documentation

For additional information, see the following:

AN-1187 Leadless Leadframe Package (LLP)

11.3 Receiving Notification of Documentation Updates

To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper

right corner, click on Alert me to register and receive a weekly digest of any product information that has

changed. For change details, review the revision history included in any revised document.

LM3550SPX/NOPB Datasheet(PDF) 37 Page - Texas Instruments

LM3550SPX/NOPB Datasheet(HTML) 37 Page - Texas Instruments

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 33 34 35 36 37 38 39 40 41 42 43

Datasheet Download

Link URL