LED7708 STMicroelectronics, LED7708 Datasheet - Page 22

• Manufacturer Part Number: LED7708
• Description: LED Lighting Drivers 16 Ch 85mA LED 3.6 to 36V 250kHz
• Manufacturer: STMicroelectronics

Specifications of LED7708

• Rohs: yes

Recommended operating conditions
22/53
Figure 5.
During normal operation, the regulation algorithm is the following:
●
●
Therefore, the possible operating configurations are shown in
Table 8.
The algorithm can also manage faulty conditions that may occur on the LED array (open
channels and LED short-circuit) in order to prevent excessive power dissipation.
The LED7708 has been designed to interface with other slave devices and can provide them
with the correct LED supply voltage by extending the above mentioned output voltage
optimization. For this purpose, some handshake signals have been reserved:
Output voltage
if at least one active channel has a voltage drop below the lower threshold, the internal
DAC counts up and the output voltage is increased
if all the active channels have a voltage drop higher than the upper threshold, the
internal DAC counts down and the output voltage is reduced.
Insufficient
Regulated
Excessive
Optimal
Simplified output regulation circuitry
Output voltage states during regulation
All the channels have their voltage above the upper threshold of the
regulation window.
All the channels have their voltage inside the regulation window.
Most of the channels have their voltage inside the regulation window; the
remaining channels have a voltage drop above the upper threshold.
At least one channel has its voltage drop below the lower threshold of the
regulation window.
Doc ID 022698 Rev 1
Condition
Table
8.
LED7708