ZXLD1362ET5TA Diodes Inc, ZXLD1362ET5TA Datasheet - Page 19

• 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

Application Information
Output Current Adjustment by PWM Control
Directly driving ADJ input
A Pulse Width Modulated (PWM) signal with duty cycle D
output current to a value above or below the nominal average value set by resistor R
Driving the ADJ input via open collector transistor
The recommended method of driving the ADJ pin and controlling the amplitude of the PWM waveform is to use a small NPN
switching transistor as shown below:
This scheme uses the 50k resistor between the ADJ pin and the internal voltage reference as a pull-up resistor for the
external transistor.
Driving the ADJ input from a microcontroller
Another possibility is to drive the device from the open drain output of a microcontroller. The diagram below shows one
method of doing this:
If the NMOS transistor within the microcontroller has high Gate / Drain capacitance, this arrangement can inject a negative
spike into ADJ input of the 1362 and cause erratic operation but the addition of a Schottky clamp diode (cathode to ADJ) to
ground and inclusion of a series resistor (3.3k) will prevent this. See the section on PWM dimming for more details of the
various modes of control using high frequency and low frequency PWM signals.
ZXLD1362
Document number: DS33472 Rev. 3 - 2
V
0V
ADJ
MCU
PWM
GND
GND
PWM
3.3k
ADJ
ADJ
ADJ
(cont.)
ZXLD1362
ZXLD1362
ZXLD1362
GND
GND
GND
www.diodes.com
PWM
19 of 28
can be applied to the ADJ pin, as shown below, to adjust the
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© Diodes Incorporated
ZXLD1362
March 2011