Datasheet LT3595 (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | 16 Channel Buck Mode LED Driver |
| Pages / Page | 16 / 10 — APPLICATIONS INFORMATION. Open LED Detection. Table 2. Recommended Output … |
| File Format / Size | PDF / 382 Kb |
| Document Language | English |
APPLICATIONS INFORMATION. Open LED Detection. Table 2. Recommended Output Capacitor Values (VLED = 3.5V). # LEDs. COUT (μF)
Model Line for this Datasheet
Text Version of Document
LT3595
APPLICATIONS INFORMATION
LED string depends on the number of LEDs and can vary
Open LED Detection
from 0.47μF to 1μF. Refer to Table 2 for proper output The LT3595 detects an open LED on any channel and capacitor selection. reports it to the ⎯O⎯P⎯E⎯N⎯L⎯E⎯D pin. The fault also reports dur-
Table 2. Recommended Output Capacitor Values (VLED = 3.5V)
ing startup until the output voltage and LED current are
# LEDs COUT (μF)
in regulation. Therefore, it can also be used as a “power 3-10 0.47 ok” signal. 1-2 1
Programming LED Current Table 3. Recommended Ceramic Capacitor Manufacturers
The set resistor (RSET in the Block Diagram) controls Taiyo Yuden (408) 573-4150 the LED current in all sixteen channels. LED current as www.t-yuden.com a function of the RSET resistance is shown in the Typical TDK (847) 803-6100 Performance Characteristics. Common values for LED cur- www.component.tdk.com rent and their required resistor values are listed in Table 4. Murata (714) 852-2001 Since resistor error directly translates to LED current error, www.murata.com precision resistors are preferred (1% is recommended). Kemet (408)-986-0424 www.kemet.com The maximum allowed resistor value is 150k. Table 3 shows a list of several ceramic capacitor manufac-
Table 4. LED Current vs RSET Resistance
turers. Consult the manufacturers for detailed information
RSET (k
Ω
) ILED (mA)
on their entire selection of ceramic parts. 150 10 75.0 20 49.9 30 37.4 40 30.1 50 3595f 10
APPLICATIONS INFORMATION
LED string depends on the number of LEDs and can vary
Open LED Detection
from 0.47μF to 1μF. Refer to Table 2 for proper output The LT3595 detects an open LED on any channel and capacitor selection. reports it to the ⎯O⎯P⎯E⎯N⎯L⎯E⎯D pin. The fault also reports dur-
Table 2. Recommended Output Capacitor Values (VLED = 3.5V)
ing startup until the output voltage and LED current are
# LEDs COUT (μF)
in regulation. Therefore, it can also be used as a “power 3-10 0.47 ok” signal. 1-2 1
Programming LED Current Table 3. Recommended Ceramic Capacitor Manufacturers
The set resistor (RSET in the Block Diagram) controls Taiyo Yuden (408) 573-4150 the LED current in all sixteen channels. LED current as www.t-yuden.com a function of the RSET resistance is shown in the Typical TDK (847) 803-6100 Performance Characteristics. Common values for LED cur- www.component.tdk.com rent and their required resistor values are listed in Table 4. Murata (714) 852-2001 Since resistor error directly translates to LED current error, www.murata.com precision resistors are preferred (1% is recommended). Kemet (408)-986-0424 www.kemet.com The maximum allowed resistor value is 150k. Table 3 shows a list of several ceramic capacitor manufac-
Table 4. LED Current vs RSET Resistance
turers. Consult the manufacturers for detailed information
RSET (k
Ω
) ILED (mA)
on their entire selection of ceramic parts. 150 10 75.0 20 49.9 30 37.4 40 30.1 50 3595f 10
