LT3474EFE#PBF Linear Technology, LT3474EFE#PBF Datasheet - Page 17

• Manufacturer Part Number: LT3474EFE#PBF
• Description: IC LED DRVR HP CONS CURR 16TSSOP
• Manufacturer: Linear Technology
• Type: High Power, Constant Currentr

Specifications of LT3474EFE#PBF

• Constant Current: Yes
• Topology: PWM, Step-Down (Buck)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Automotive, Backlight
• Type - Secondary: Color, White LED
• Frequency: 200kHz ~ 2MHz
• Voltage - Supply: 3.5 V ~ 36 V
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP Exposed Pad, 16-eTSSOP, 16-HTSSOP
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 1A
• Internal Switch(s): Yes
• No. Of Outputs: 1
• Output Current: 1A
• Output Voltage: 15V
• Input Voltage: 4V To 36V
• Dimming Control Type: PWM
• Operating Temperature Range: -40°C To +85°C
• Driver Case Style: TSSOP
• Rohs Compliant: Yes
• Led Driver Application: Automotive, Avionic Lighting
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Efficiency: -

APPLICATIONS INFORMATION
LED Voltage Range
The LT3474 can drive LED voltages from 2.4V to 12V. The
LT3474-1 can drive LED voltages from 2.4V to 30V. Be
careful not to exceed the ABSMAX rating of the OUT, LED,
or BOOST pins of the LT3474-1 since the internal output
clamp is disabled. See the Typical Application section for
an example of adding an external output clamp. If the
LED voltage can drift below 2.4V due to temperature or
component variation, add extra series resistance to bring
the overall voltage above 2.4V.
Layout Hints
As with all switching regulators, careful attention must
be paid to the PCB layout and component placement. To
maximize effi ciency, switch rise and fall times are made
Figure 8. Recommended Component Placement
VIA TO LOCAL GND PLANE
VIA TO OUT
V
IN
PWM
as short as possible. To prevent electromagnetic interfer-
ence (EMI) problems, proper layout of the high frequency
switching path is essential. The voltage signal of the SW
and BOOST pins have sharp rise and fall edges. Minimize
the area of all traces connected to the BOOST and SW
pins and always use a ground plane under the switching
regulator to minimize interplane coupling. In addition, the
ground connection for frequency setting resistor R
to Figure 1) should be tied directly to the GND pin and
not shared with any other component, ensuring a clean,
noise-free connection.
SHDN
GND
LT3474/LT3474-1
17
T
(refer
3474fd