ZLED7730ZI1R ZMDI, ZLED7730ZI1R Datasheet - Page 14

• Manufacturer Part Number: ZLED7730ZI1R
• Description: LED Lighting Drivers LED driver
• Manufacturer: ZMDI

Specifications of ZLED7730ZI1R

• Rohs: yes
• Input Voltage: 8.5 V to 40 V
• Operating Frequency: 1 MHz
• Maximum Supply Current: 600 uA
• Output Current: 0.35 A
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Package / Case: SOP-8
• Minimum Operating Temperature: - 40 C
• Power Dissipation: 500 mW

The input conditions on the DIM1 and DIM2 pins set the number of current levels and the current ratio relative to
the initial average current for the dimming switch (DS) sequences as shown in Table 2.1.
Table 2.1
If a normal switch is detected or if DIM1 and DIM2 are both floating, the output current goes back to the initial
state of 100% nominal average output current. Since ZLED7x30 needs to count the time for more than 2 seconds
after the switch is off during a normal switch, one capacitor (C1) equal to or greater than 220µF is required to
keep the chip working in low quiescent current mode during this part of the off-time.
2.4
2.4.1
The ZLED7x30 automatically protects itself from damage due to over-temperature conditions. If the ZLED7x30’s
temperature exceeds the thermal shutdown threshold (T
avoid erratic ZLED7x30 operation, a 20K hysteresis (T
until its temperature falls below the hysteresis threshold (T
thermal considerations.
2.4.2
As a step-down converter, the ZLED7x30 has inherent open-load circuit protection. Since the L1 inductor is
connected in series with the LED string, the current flow is interrupted if the load is open and the LX output of the
ZLED7x30 will not be damaged. This provides an advantage over other products such as boost converters, for
which the internal switch can be damaged by back EMF forcing the drain above its breakdown voltage.
Data Sheet
August 16, 2011
Dimming Mode
K
ZLED7730
High Current 40V LED Driver with Switch Dimming
No dimming
X
= Current ratio to initial current (see section 1.3).
ZLED7x30 Protection Features
Thermal Shut-down Protection
LED Open-Load Protection
1
2
3
Dimming Configuration Options
© 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.
Floating
Floating
GND
GND
DIM1
Floating
GND
Floating
GND
DIM2
(100%)
100%
100%
100%
1
1
1
st
st
st
SD-HYS
DS
DS
DS
SD
) is applied that prevents it from returning to operation
SD
50%
60%
30%
= 150° C, typical), the ZLED7x30 will shutdown. To
- T
Dimming Ratio K
SD-HYS
2
2
2
nd
nd
nd
DS
DS
DS
). Also refer to section 3.2 for additional
20%
30%
100% …
3
3
rd
rd
DS
DS
100% …
100% …
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