ZXLD1321DCATC Diodes Zetex, ZXLD1321DCATC Datasheet - Page 12

• Manufacturer Part Number: ZXLD1321DCATC
• Description: IC LED DRVR WHITE BCKLGT 14-TDFN
• Manufacturer: Diodes Zetex
• Type: Backlight, White LEDr

Specifications of ZXLD1321DCATC

• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Flash/Torch
• Type - Secondary: High Brightness LED (HBLED), White LED
• Frequency: 600kHz
• Voltage - Supply: 2 V ~ 12 V
• Mounting Type: Surface Mount
• Package / Case: 14-TDFN
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 1A
• Internal Switch(s): Yes
• Efficiency: 85%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Other names: ZXLD1321DCATR

PWM control
A wider dimming range can be achieved by applying a PWM control signal to the ADJ pin to turn
the device on and off, giving an average output current proportional to the duty cycle of the
control signal. The ADJ pin can be driven directly from the open drain NMOS output of a
microcontroller, or indirectly with a low saturation voltage NPN transistor such as the Zetex
ZXTN25015DFH. (Fig 2).
In the circuit of Fig 4, the average LED output current will be
Where duty cycle
A PWM frequency of 200Hz, or lower is recommended, to minimize errors due to the rise and fall
times of the converter output.
Issue 1 - January 2008
© Zetex Semiconductors plc 2008
I
D
LED
(
avg
(
)
T
1
T
2
T
) 2
I
LED
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D
ZXTN25015DFH
Fig 1
Fig 2
12
ADJ
ZXLD1321
ZXLD1321
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