zxld1370 Diodes, Inc., zxld1370 Datasheet - Page 23

• Manufacturer Part Number: zxld1370
• Description: 60v High Accuracy Buck/boost/buck-boost Led Driver Controller
• Manufacturer: Diodes, Inc.

ZXLD1370
Document number: DS32165 Rev. 2 - 2
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. This will produce an
average output current proportional to the duty
cycle of the control signal. During PWM operation,
the device remains 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.
Fig 32: Stand-by state from PWM signal
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Figure 31:PWM dimming minimum and maximum pulse
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PWM
Gate
0V
0V
2µs
Diodes Incorporated
A Product Line of
< 10 ms
2µs
< 10 ms
© Diodes Incorporated
ZXLD1370
May 2010