L6520TR STMicroelectronics, L6520TR Datasheet - Page 12

• Manufacturer Part Number: L6520TR
• Description: IC BALLAST CTRL TL/CFL 8-SOIC
• Manufacturer: STMicroelectronics
• Type: Ballast Controllerr

Specifications of L6520TR

• Current - Supply: 8mA
• Current - Output: 300mA
• Voltage - Supply: 10.5 V ~ 18.5 V
• Operating Temperature: -25°C ~ 85°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency: -
• Lead Free Status / Rohs Status: Details
• Other names: 497-11128-2

Functions description
5.6.4
5.7
12/19
Choke saturation control (CSC) during ignition and run mode
The same thresholds used to detect OCPH and OCPL are active.
The control is still based on the time between two consecutive thresholds but its behavior is
different with respect to the OCPH/OCPL detection to take into account the increase of dI/dt
when the inductor is saturating. When either the two lower thresholds are crossed in a time
shorter than 255 ns or the higher threshold is crossed, the LS driver is immediately turned
off and the time between the LS turn on and the instant when the second threshold (THM or
TLM) is crossed is used to calculate the new (higher) frequency.
If this new frequency is higher than 100 kHz then the new frequency will be set at 100 kHz.
The frequency is then decreased with a fixed df/dt equal to df
frequency at which the first threshold was crossed is reached. Then, the decreasing ratio
becomes again df
ratio is maintained until run frequency is reached.
If the run frequency has not been reached after 200 ms from when the lower threshold was
crossed the first time, the IC is turned off (latched).
A leading edge blanking of 255 ns is active.
End of life (EOL)
An embedded window comparator can be used to detect the end of life (EOL) when the
lamp is directly connected to ground (lamp to ground configuration).
After the ignition sequence, the EOL window comparator becomes active. When the voltage
at EOL pin goes outside the limits of this comparator a 1.5 s timer is started. If the EOL pin
voltage does not return inside the allowed range before the end of the timer, the IC is shut
down (latched).
The EOL pin is biased to the center of the window comparator by means of an OTA (2.5 V
typ. with +/- 1.5 V typ. window), having a current capability equal to 9.1 µA (typ.).
IGN
/dt during ignition whereas, during run mode, the df
Doc ID 16998 Rev 3
CCC
/dt = - 500 Hz/ms, until the
CCC
/dt decreasing
L6520, L6521