LED7707 STMicroelectronics, LED7707 Datasheet - Page 24

• Manufacturer Part Number: LED7707
• Description: LED Drivers 6-ROW 85mA LED DRIV BOOST REG LCD PANEL
• Manufacturer: STMicroelectronics

Specifications of LED7707

• High Level Output Current: 85 mA
• Operating Supply Voltage: 4.5 V to 36 V
• Maximum Supply Current: 1 mA
• Maximum Power Dissipation: 2.3 W
• Maximum Operating Temperature: + 150 C
• Mounting Style: SMD/SMT
• Package / Case: VFQFPN-24
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Operation description
24/47
At the point marked as “1” in
across the current generator of the channel where the failed LED is connected increases by
an amount equal to the forward voltage of the faulty LED. Since the voltage across the
current generator is above the threshold (4 V), the device is turned off and the fault pin is set
low (point “2”). Note that, once a new dimming cycle starts (point “3”), the device waits the
masking time (approximately 100 μs) and then sets the FAULT pin low and turns off.
Figure 17. Shorted LED detection (MODE to GND)
Figure 17
masking time
masking time
1
1 1
one LED fails becoming a short-circuit. The voltage
3
3 3
2
2 2
LED7707