ZSLS7025ZI1R ZMDI, ZSLS7025ZI1R Datasheet - Page 14

• 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

2.6.3
Figure 2.4 shows the configuration for using an external PWM signal with a dimming control MOSFET Q
the PWM input is high (V
When the PWM signal is low (V
ZSLS7025 is shutdown. Using a fixed frequency PWM signal and changing the duty cycle adjusts the average
LED current. The recommended 5V PWM frequency is between 200Hz and 1KHz.
Figure 2.4
2.7
The ZSLS7025 limits the peak inductor current and therefore the peak input current through the feedback path of
R
based on the boost ratio V
current can be calculated with equation (5):
Where
CS
Data Sheet
June 28, 2012
ZSLS7025
Boost LED Driver
connected from the source of the external MOSFET (Q

= Assumed power conversion efficiency (recommended value for calculation: 0.9)
Peak Input Current Control
I
IN
PWM Dimming with a Dimming Control MOSFET (Q
_
AVG
PWM Dimming Circuit Using a Dimming Control MOSFET (Q

V
© 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.
V
OUT
V
IN
IN
C
=5 to 100 VDC
C
VDD
PWM Control Signal


IN
I
OUT

H
>2.4V), Q
OUT
R
/V
VDD
R
IN
TOFF
L
<0.5V), Q
and the designed value for average LED current. The required average input
2
is on and the ZSLS7025 operates normally to regulate the output current.
VDD
TOFF
ADJ
GND
ZSLS7025
2
is off; the input voltage on the FB pin will be below V
L
1
GATE
OVP
CS
FB
1
) to ground. The required average input current is
2
Q
)
R
1
CS
D
1
2
)
R
R
1
2
C
OUT
R
FB
Q
2
String
LED
14 of 27
(5)
FB
2
and the
. When