ZLED7520ZI1R ZMDI, ZLED7520ZI1R Datasheet - Page 18

• Manufacturer Part Number: ZLED7520ZI1R
• Description: LED Lighting Drivers LED driver
• Manufacturer: ZMDI

Specifications of ZLED7520ZI1R

• Rohs: yes
• Input Voltage: 6 V to 40 V
• Operating Frequency: 1 MHz
• Maximum Supply Current: 600 uA
• Output Current: 0.75 A
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Package / Case: DFN-5
• Minimum Operating Temperature: - 40 C
• Power Dissipation: 500 mW

To ensure stable output current, use a 1% accuracy resistor with adequate power tolerance and a good
temperature characteristic for Rs.
Table 3.1
3.3.2
The recommended range for the L1 inductor is 33µH to 220µH. Select the inductor value for L1 as needed to
ensure that switch on/off times are optimized across the load current and supply voltage ranges. If the application
requires a high supply voltage and low output current, inductance values at the high end of this range are recom-
mended to minimize errors due to switching delays, which can reduce efficiency and increase ripple on the output.
Also see section 3.4 for layout considerations for L1. Equations (3) and (4) can be used to calculate t
On Time for LX Switch (t
Off Time for LX Switch (t
Where:
t
t
L
V
V
I
Rs
r
R
V
Data Sheet
August 12, 2011
Nominal Average Output Current (mA)
AVG
L
ON
OFF
I
IN
LED
D
LX
ZLED7520
High Current 40V LED Driver with Internal Switch
Symbol
1200 (maximum for ZLED7020)
1000 (maximum for ZLED7320)
750 (maximum for ZLED7520)
350 (maximum for ZLED7720)
V
V
Inductor L1
IN
LED
Recommended Values for Sense Resistor Rs (ADJ pin floating at nominal voltage V
V
LED
V
D
© 2011 Zentrum Mikroelektronik Dresden AG — Rev. 1.2
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.
667
333
L
L1 coil inductance in H
L1 coil peak-peak ripple current in A (internally set to 0.3
Supply voltage in V
Total forward voltage in V for LED string
Nominal average LED current in A
External current sense resistor in
L1 coil resistance in
LX switch resistance in
D1 diode forward voltage at the required load current in V
I
I
*
AVG
ONmin
OFFmin
AVG
L
*
I
( *
( *
>200ns):
>200ns):
I
R
R
S
S
r
r
L
L
)
R
LX
)
Value for R
0.082
0.13
0.15
0.27
0.1
0.3
Description
S
( )
I
AVG
)
REF
=1.2V)
(3)
(4)
ON
18 of 27
and t
OFF
.