LED2000PUR STMicroelectronics, LED2000PUR Datasheet - Page 19

• Manufacturer Part Number: LED2000PUR
• Description: LED Lighting Drivers 3.0V to 18V 850kHz 100mV 95mOhm HS
• Manufacturer: STMicroelectronics

Specifications of LED2000PUR

• Rohs: yes
• Input Voltage: 3 V to 18 V
• Operating Frequency: 850 kHz
• Maximum Supply Current: 3 A
• Mounting Style: SMD/SMT
• Package / Case: VFQFPN-8L
• Power Dissipation: 2 W

LED2000
Application notes
Figure 11. Dimming operation example
AM12902v1
In fact, when dimming enables the switching activity, a small capacitor value is fast charged
with low inductor value. As a consequence, the LEDs current rising edge time is improved
and the inductor current oscillation reduced. An oversized output capacitor value requires
extra current for fast charge so generating certain inductor current oscillations
The switching activity is prevented as soon as the dimming signal goes low. Nevertheless,
the LED current drops to zero only when the voltage stored in the output capacitor goes
below a minimum voltage determined by the selected LEDs. As a consequence, a big
capacitor value makes the LED current falling time worse than a smaller one.
The LED2000 embeds dedicated circuitry to improve LED current falling time.
As soon as the dimming input goes low, the low-side is kept enabled to discharge C
until
OUT
the LED current drops to 60% of the nominal current. A negative current limitation (-1 A
typical) protects the device during this operation (see
Figure
12).
Doc ID 023432 Rev 3
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