ltm8040 Linear Technology Corporation, ltm8040 Datasheet - Page 12

• Manufacturer Part Number: ltm8040
• Description: 36v, 1a ?module Led Driver
• Manufacturer: Linear Technology Corporation

continuous operation under this operating condition may
impair reliability.
Layout Hints
Most of the headaches associated with PCB layout have
been alleviated or even eliminated by the high level of in-
tegration of the LTM8040. The LTM8040 is nevertheless a
switching power supply, and care must be taken to minimize
EMI and ensure proper operation. Even with the high level
of integration, you may fail to achieve specifi ed operation
with a haphazard or poor layout. See Figure 6 for a sug-
gested layout. Ensure that the grounding and heatsinking
are acceptable. A few rules to keep in mind are:
1. Place the C
LTM8040
APPLICATION INFORMATION
12
and GND connection of the LTM8040.
IN
STRING
capacitor as close as possible to the V
LED
VIAS TO GND PLANE
LEDA
GND
Figure 6. Suggested Layout
IN
2. Connect all of the GND connections to as large a cop-
3. Use vias to connect the GND copper area to the board’s
4. If the application requires BIAS to be connected to the
per pour or plane area as possible on the top layer.
Avoid breaking the ground connection between the
external components and the LTM8040.
internal ground plane. Liberally distribute these GND
vias to provide both a good ground connection and
thermal path to the internal planes of the printed circuit
board.
input voltage potential, tie BIAS to V
not to break up the ground plane.
C
IN
V
IN
LPWR
BIAS
ADJ
RT
PWM
SHDN
8040 F06
IN
, but be careful
8040p