ZSLS7025ZI1R ZMDI, ZSLS7025ZI1R Datasheet - Page 20

• Manufacturer Part Number: ZSLS7025ZI1R
• Description: LED Lighting Drivers LED Driver
• Manufacturer: ZMDI

Specifications of ZSLS7025ZI1R

• Rohs: yes
• Input Voltage: 5 V
• Maximum Supply Current: 400 uA
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-8
• Minimum Operating Temperature: - 40 C

4.3
The guidelines in this section are strongly recommended when laying out application circuits. As for all switching
power supplies, especially those providing high current and using high switching frequencies, layout is an impor-
tant design step. If the layout is not well-designed, the regulator could show instability as well as EMI problems.
For additional guidelines, refer to the ZMDI application note PCB Layout Design Guidelines for LED Driver
Circuits available at www.zmdi.com/products/led-drivers/.
4.4
This section provides an example of an application design for the ZSLS7025 for the RC-filter PWM application
described in section 2.6.2 and shown again for reference in Figure 4.2.
Design criteria:
To calculate the worst case parameters, use the minimum input voltage, maximum output voltage, and maximum
output current; i.e., V
Data Sheet
June 28, 2012
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ZSLS7025
Boost LED Driver
Wide traces should be used for connection of the high current loop to minimize the EMI and unnecessary
loss.
The external components ground should be connected to the ZSLS7025 ground and should be as short as
possible. It is especially important that the R
as possible to have an accurate LED current.
The capacitors C
filtering. It is especially important that the C
The Q
a dimming control MOSFET as described in section 2.6.3). The inductor L
be placed as close as possible to the drain, and the connection should be kept as short and wide as
possible. Avoid other traces crossing and routing too long in parallel with this node to minimize the noise
coupling into these traces. The feedback pins (i.e., CS, FB, OVP) should be as short as possible and
routed away from the inductor, Schottky diode, and Q
shielded with a ground plane or trace to minimize noise coupling into this circuit.
The thermal pad on the back of the external MOSFET package must be soldered to the large ground plane
for ideal heat distribution.
Application Circuit Layout Requirements
Application Example
V
I
V
OUT
IN
OUT
= 12 to 24 V
= 350mA
1
= 30 to 40V (9 to 12 LEDs, Vf = 3.3V)
external MOSFET drain is a fast switching node (also applies to Q
© 2012 Zentrum Mikroelektronik Dresden AG — Rev.1.00
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
IN
= 12V, I
IN
, C
VDD
OUT
, and C
= 350mA, and V
OUT
should be placed as close as possible to the ZSLS7025 for good
OUT
FB
OUT
ground to ZSLS7025 ground connection is as short and wide
output capacitor connection is as short and wide as possible.
≈ 40V (12 LEDs, Vf = 3.3V).
1
. The feedback pins and feedback network should be
2
1
if the PWM is accomplished with
and Schottky diode D
20 of 27
1
should