ZXLD1350ET5TA Diodes Zetex, ZXLD1350ET5TA Datasheet - Page 14

• Manufacturer Part Number: ZXLD1350ET5TA
• Description: IC LED DRIVR WHITE BCKLGT TSOT-5
• Manufacturer: Diodes Zetex
• Type: Backlight, White LEDr

Specifications of ZXLD1350ET5TA

• Topology: PWM, Step-Down (Buck)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Automotive
• Type - Secondary: High Brightness LED (HBLED), White LED
• Frequency: 1MHz
• Voltage - Supply: 7 V ~ 30 V
• Voltage - Output: 30V
• Mounting Type: Surface Mount
• Package / Case: TSOT-23-5, TSOT-5, TSOP-5
• Operating Temperature: -40°C ~ 105°C
• Current - Output / Channel: 350mA
• Internal Switch(s): Yes
• Efficiency: 95%
• Operating Supply Voltage (typ): 9/12/15/18/24V
• Number Of Segments: 3
• Operating Temperature (min): -40C
• Operating Temperature (max): 105C
• Operating Temperature Classification: Industrial
• Package Type: TSOT-23
• Pin Count: 5
• Mounting: Surface Mount
• Power Dissipation: 450mW
• Operating Supply Voltage (min): 7V
• Operating Supply Voltage (max): 30V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ZXLD1350ET5TR

ZXLD1350
Document number: DS33468 Rev. 8 - 2
Application Information (Continued)
Low frequency PWM mode
When the ADJ pin is driven with a low frequency PWM signal (eg 100Hz), with a high level voltage V
zero, the output of the internal low pass filter will swing between 0V and V
below its turn-off threshold (200mV nom) when the ADJ pin is low. This will cause the output current to be switched on and off
at the PWM frequency, resulting in an average output current I
frequency PWM operating waveforms).
The average value of output current in this mode is given by:
I
This mode is preferable if optimum LED 'whiteness' is required. It will also provide the widest possible dimming range
(approx. 100:1) and higher efficiency at the expense of greater output ripple.
Note that the low pass filter introduces a small error in the output duty cycle due to the difference between the start-up and
shut-down times. This time difference is a result of the 200mV shutdown threshold and the rise and fall times at the output of
the filter. To minimize this error, the PWM duty cycle should be as low as possible consistent with avoiding flicker in the LED.
OUTavg
0.1D
PWM
/R
S
for D
PWM
>0 01
Figure 2. Low frequency PWM operating waveforms
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OUTavg
30V 350mA LED DRIVER with AEC-Q100
proportional to the PWM duty cycle. (See Figure 2 - Low
ADJ
, causing the input to the shutdown circuit to fall
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A Product Line of
ADJ
and a low level of
© Diodes Incorporated
ZXLD1350
March 2011