ZXLD1350ET5 Diodes Inc, ZXLD1350ET5 Datasheet - Page 15

• Manufacturer Part Number: ZXLD1350ET5
• Description: IC, LED DRIVER, BUCK, TSOT-23-5
• Manufacturer: Diodes Inc

Specifications of ZXLD1350ET5

• Led Driver Application: Automotive Lighting, Illuminated Signs
• No. Of Outputs: 1
• Output Current: 350mA
• Output Voltage: 30V
• Input Voltage: 7V To 30V
• Dimming Control Type: PWM / DC
• Topology: Buck
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ZXLD1350
Document number: DS33468 Rev. 8 - 2
Application Information (Continued)
High frequency PWM mode
At PWM frequencies above 10kHz and for duty cycles above 0.16, the output of the internal low pass filter will contain a
DC component that is always above the shutdown threshold. This will maintain continuous device operation and the nominal
average output current will be proportional to the average voltage at the output of the filter, which is directly proportional to the
duty cycle. (See Figure 3 – High frequency PWM operating waveforms). For best results, the PWM frequency should be
maintained above the minimum specified value of 10kHz, in order to minimize ripple at the output of the filter. The shutdown
comparator has approximately 50mV of hysteresis, to minimize erratic switching due to this ripple. An upper PWM frequency
limit of approximately one tenth of the operating frequency is recommended, to avoid excessive output modulation and to
avoid injecting excessive noise into the internal reference.
The nominal average value of output current in this mode is given by:
I
This mode will give minimum output ripple and reduced radiated emission, but with a reduced dimming range (approx.5:1).
The restricted dimming range is a result of the device being turned off when the DC component on the filter output falls below
200mV.
Shutdown mode
Taking the ADJ pin to a voltage below 0.2V for more than approximately 100μs, will turn off the output and supply current will
fall to a low standby level of 15μA nominal.
Note that the ADJ pin is not a logic input. Taking the ADJ pin to a voltage above V
100% nominal average value. (See graphs for details).
OUTnom
»0.1D
PWM
/R
S
for D
PWM
>0.16
Figure 3. High Frequency PWM operating waveforms
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30V 350mA LED DRIVER with AEC-Q100
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will increase output current above the
© Diodes Incorporated
ZXLD1350
March 2011