Nxp Semiconductors SSL2101 Evaluation Boards SSL2101T/DB/FBCB120V,598 SSL2101T/DB/FBCB120V,598 Scheda Tecnica
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SSL2101T/DB/FBCB120V,598
SSL2101
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© NXP B.V. 2011. All rights reserved.
Product data sheet
Rev. 4.1 — 5 December 2011
6 of 23
NXP Semiconductors
SSL2101
Dimmable Greenchip driver for LED lighting
A typical RC waveform is given in
. The RC switch-over threshold is controlled by
the BRIGHTNESS pin.
To ensure that the capacitor can be charged within the charge time, the value of the
oscillator capacitor should be limited to 1 nF. Due to leakage current, the value of the
resistor connected between the RC pin and the ground should be limited to a maximum of
220 k
oscillator capacitor should be limited to 1 nF. Due to leakage current, the value of the
resistor connected between the RC pin and the ground should be limited to a maximum of
220 k
.
8.3 Duty factor control
The duty factor is controlled by an internally regulated voltage and the oscillator signal on
pin RC. The internal regulation voltage is set by the voltage on the PWMLIMIT pin.
pin RC. The internal regulation voltage is set by the voltage on the PWMLIMIT pin.
A low PWMLIMIT voltage will results in a low on-time for the internal power switch. The
minimum duty factor of the switched mode power supply can be set to 0 %. The maximum
duty factor is set to 75 %.
minimum duty factor of the switched mode power supply can be set to 0 %. The maximum
duty factor is set to 75 %.
Fig 3.
Brightness control block
Fig 4.
Brightness timing waveform
STARplug
OSCILLATOR
24
μ
A
5 V
rc_threshold
Comparator
R2
10 k
Ω
R1
220 k
220 k
Ω
C1
330 pF
330 pF
BRIGHTNESS
RC
RC2
V
V
014aaa574
time
014aaa582
rc_threshhold
75 mV
RC voltage
Voltage
(mV)