ZXLD1356ET5TA Diodes Zetex, ZXLD1356ET5TA Datasheet - Page 24

• Manufacturer Part Number: ZXLD1356ET5TA
• Description: IC LED DRIVR WHITE BCKLGT TSOT-5
• Manufacturer: Diodes Zetex
• Type: Backlight, White LEDr

Specifications of ZXLD1356ET5TA

• Topology: PWM, Step-Down (Buck)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Automotive, Backlight
• Type - Secondary: High Brightness LED (HBLED), White LED
• Frequency: 500kHz
• Voltage - Supply: 6 V ~ 60 V
• Voltage - Output: 60V
• Mounting Type: Surface Mount
• Package / Case: TSOT-23-5, TSOT-5, TSOP-5
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 550mA
• Internal Switch(s): Yes
• Efficiency: 97%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ZXLD1356ET5TR

Application Information
Thermal considerations
When operating the device at high ambient temperatures, or when driving maximum load current, care must be taken to avoid
exceeding the package power dissipation limits. The graph below gives details for power derating. This assumes the device to be
mounted on a (25mm)
Note that the device power dissipation will most often be a maximum at minimum supply voltage. It will also increase if the
efficiency of the circuit is low. This may result from the use of unsuitable coils, or excessive parasitic output capacitance on the
switch output.
Thermal compensation of output current
High luminance LEDs often need to be supplied with a temperature compensated current in order to maintain stable and reliable
operation at all drive levels. The LEDs are usually mounted remotely from the device so, for this reason, the temperature
coefficients of the internal circuits for the ZXLD1356 have been optimized to minimize the change in output current when no
compensation is employed. If output current compensation is required, it is possible to use an external temperature sensing
network - normally using Negative Temperature Coefficient (NTC) thermistors and/or diodes, mounted very close to the LED(s).
The output of the sensing network can be used to drive the ADJ pin in order to reduce output current with increasing
temperature.
ZXLD1356
Document number: DS33470 Rev. 3 - 2
1.8
1.6
1.4
1.2
0.8
0.6
0.4
0.2
2
1
0
-40
2
PCB with 1oz copper standing in still air.
-25
-10
(Continued)
TSOT23-5
5
20
Maximum Power Dissipation
Ambient Temperature (°C)
35
DFN3030-6
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ZXLD1356
December 2010