ZLED7520ZI1R ZMDI, ZLED7520ZI1R Datasheet - Page 17

• 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

Figure 3.4
3.2
3.2.1
Do not exceed the package power dissipation limits by driving high load currents or by operating the chip at high
ambient temperatures. Power dissipation also increases if the efficiency of the circuit is low as could result from
selecting the wrong coil or from excessive parasitic output capacitance on the switch output. See the layout
guidelines in section 3.4.
3.2.2
Until the supply input voltage on the V
internal regulator disables the drive to the internal power MOSFET output switch. Above this threshold, the
MOSFET on-resistance is low enough for the chip to start to operate; however, if the supply voltage remains
below the specified minimum (6V), the duty cycle of the output switch will be high and the ZLED7x20 power
dissipation will be at a maximum. Avoid operating the ZLED7x20 under such conditions to reduce the risk of
damage due to exceeding the maximum die temperature. When driving multiple LEDs, their combined forward
voltage drop is typically high enough to prevent the chip from switching when V
of thermal damage.
3.3
Note: Also see section 3.4 for layout guidelines for the following external components.
3.3.1
Table 3.1 gives values for Rs under normal operating conditions in the typical application shown in Figure 3.1.
These values assume that the ADJ pin is floating and at the nominal voltage of V
Note: Under the conditions given in Table 3.1, in order to maintain the switch current below the maximum value
specified in section 1, 0.082
the ZLED7520 and 0.27
from an external voltage.
Data Sheet
August 12, 2011
ZLED7520
High Current 40V LED Driver with Internal Switch
Thermal Considerations for Application Design
External Component Selection
Temperature Effects of Load, Layout, and Component Selection
Temperature Effects of Low Supply Voltage V
Sense Resistor Rs
Basic ZLED7x20 Application Circuit with Output Current Controlled by External Microcontroller Signal
© 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.
for the ZLED7720. It is possible to use different values of Rs if the ADJ pin is driven
is the minimum value for Rs for the ZLED7020, 0.1
IN
pin has risen above the internally-set startup threshold, the ZLED7x20’s
IN
IN
REF
is below 6V, so there is less risk
=1.2V.
for the ZLED7320, 0.13
17 of 27
for