Strobe

VSENSE

(50 mV/DIV)

VALD/TEMP

(500 mV/DIV)

TIME

(10 ms/DIV)

Strobe

VSENSE

(50 mV/DIV)

VALD/TEMP

(500 mV/DIV)

TIME

(10 ms/DIV)

32

LM3550

SNVS569C – MAY 2009 – REVISED OCTOBER 2016

www.ti.com

Product Folder Links: LM3550

Submit Documentation Feedback

Copyright © 2009–2016, Texas Instruments Incorporated

The flash current drops to 70% of the peak once the voltage on the ALD/TEMP pin exceeds the sense low trip point.

Figure 52. Effect of ALD/TEMP Voltage Rising During a Flash

The flash event is not allowed to start if the voltage on ALD/TEMP is higher that the sense high trip point.

Figure 53. Effect of ALD/TEMP Voltage Dropping During a Flash

8.2.2.1.5

Thermal Protection

Internal thermal protection circuitry disables the LM3550 when the junction temperature exceeds 145°C (typical).

This feature protects the device from being damaged by high die temperatures that might otherwise result from

excessive power dissipation. The device recovers and operates normally when the junction temperature falls

below 125°C (typical). It is important that the board layout provide good thermal conduction to keep the junction

temperature within the specified operating ratings.