ZXLD1370_11 DIODES [Diodes Incorporated], ZXLD1370_11 Datasheet - Page 24

• Manufacturer Part Number: ZXLD1370_11
• Description: 60V HIGH ACCURACY BUCK/BOOST/BUCK-BOOST LED DRIVER CONTROLLER
• Manufacturer: DIODES [Diodes Incorporated]

ZXLD1370
Document number: DS32165 Rev. 3 - 2
Applications Information
LED current can be adjusted digitally, by applying a low
frequency PWM logic signal to the PWM pin to turn the
controller on and off.
output current proportional to the duty cycle of the control
signal.
powered up and only the output switch is gated by the
control signal.
The PWM signal can achieve very high LED current
resolution. In fact, dimming down from 100% to 0, a
minimum pulse width of 2µs can be achieved resulting in
very high accuracy. While the maximum recommended
pulse is for the PWM signal is10ms.
The device can be put in standby by taking the PWM pin to ground, or pulling it to a voltage below 0.4V with a suitable open
collector NPN or open drain NMOS transistor, for a time exceeding 15ms (nominal). In the shutdown state, most of the
circuitry inside the device is switched off and residual quiescent current will be typically 90µA. In particular, the Status pin
will go down to GND while the FLAG and REF pins will stay at their nominal values.
Figure 29. PWM dimming from open collector switch
During PWM operation, the device remains
This will produce an average
(Continued)
Fig 32. Stand-by state from PWM signal
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Figure 31. PWM dimming minimum and maximum pulse
PWM
Gate
0V
0V
Figure 30. PWM dimming from MCU
2µs
Diodes Incorporated
A Product Line of
< 10 ms
2µs
© Diodes Incorporated
< 10 ms
ZXLD1370
February 2011