ZXLD1362ET5TA Diodes Inc, ZXLD1362ET5TA Datasheet - Page 23

• Manufacturer Part Number: ZXLD1362ET5TA
• Description: LED Drivers 1A/60V LED DRIVER
• Manufacturer: Diodes Inc

Specifications of ZXLD1362ET5TA

• Operating Supply Voltage: 6 V to 60 V
• Maximum Power Dissipation: 1000 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: TSOT-23
• Minimum Operating Temperature: - 40 C
• Led Driver Application: Automotive Lighting, Illuminated Signs
• Topology: Buck (Step Down)
• No. Of Outputs: 1
• Output Current: 1A
• Input Voltage: 6V To 60V
• Dimming Control Type: PWM / DC
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

A Product Line of
Diodes Incorporated
ZXLD1362
Application Information
(cont.)
Diode Selection
For maximum efficiency and performance, the rectifier (D1) should be a fast low capacitance Schottky diode* with low
reverse leakage at the maximum operating voltage and temperature.
They also provide better efficiency than silicon diodes, due to a combination of lower forward voltage and reduced recovery
time.
It is important to select parts with a peak current rating above the peak coil current and a continuous current rating higher
than the maximum output load current. It is very important to consider the reverse leakage of the diode when operating
above 85°C. Excess leakage will increase the power dissipation in the device and if close to the load may create a thermal
runaway condition.
The higher forward voltage and overshoot due to reverse recovery time in silicon diodes will increase the peak voltage on
the LX output. If a silicon diode is used, care should be taken to ensure that the total voltage appearing on the LX pin
including supply ripple, does not exceed the specified maximum value.
*A suitable Schottky diode would be 30BQ100PBF (IR).
Reducing Output Ripple
Peak to peak ripple current in the LED(s) can be reduced, if required, by shunting a capacitor Cled across the LED(s) as
shown below:
Rs
V
IN
LED
Cled
L1
D1
V
I
LX
IN
SE NSE
ZXLD1362
A value of 1μF will reduce the supply ripple current by a factor three (approx.). Proportionally lower ripple can be achieved
with higher capacitor values. Note that the capacitor will not affect operating frequency or efficiency, but it will increase start-
up delay, by reducing the rate of rise of LED voltage.
By adding this capacitor the current waveform through the LED(s) changes from a triangular ramp to a more sinusoidal
version without altering the mean current value.
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ZXLD1362
March 2011
www.diodes.com
© Diodes Incorporated
Document number: DS33472 Rev. 3 - 2