SSL2101T/DB/FBCB120V,598 NXP Semiconductors, SSL2101T/DB/FBCB120V,598 Datasheet - Page 10

• Manufacturer Part Number: SSL2101T/DB/FBCB120V,598
• Description: BOARD EVAL LED DRIVER SS2101
• Manufacturer: NXP Semiconductors
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of SSL2101T/DB/FBCB120V,598

• Current - Output / Channel: 400 mA ~ 800 mA
• Outputs And Type: 1, Isolated
• Voltage - Output: 9 ~ 23 V
• Features: Dimmable, TRIAC Dimmable
• Voltage - Input: 120VAC
• Utilized Ic / Part: SSL2101
• Input Voltage: 120 V
• Board Size: 103 mm x 50 mm x 20 mm
• Maximum Operating Temperature: + 100 C
• Minimum Operating Temperature: - 40 C
• Operating Supply Voltage: 8.5 V to 40 V
• Product: Power Management Modules
• Dimensions: 103 mm x 50 mm x 20 mm
• For Use With/related Products: SSL2101T
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 568-4812

NXP Semiconductors
UM10341
User manual
the LC filter within the dimmer. A serial resistor can be used for this for low power ranges
(<10 W) but for higher power ranges a single series resistor is not efficient. This is
because the converter supply current will cause significant voltage drop and thus
dissipation through this resistor. To improve efficiency, a combination of serial resistance
and a parallel damper has been chosen for the demonstration board. The serial resistor is
made up of F1, R1, R2 and R12 and the parallel damper comprises C2 and R3 (see
Figure
The input circuit of the converter must be equipped with a filter that is partially capacitive.
The combination of C1, L1, L2, C3 and C4 makes a filter that blocks most of the
disturbance generated by the converter input current. A drawback of this filter is a
reduction of power factor, due to the capacitive load. A lower converter power, in relation
to the capacitive value of this filter/buffer, will cause a lower power factor. The 230 V (AC)
design uses 150 nF capacitors, which attain a power factor of 0.9 for an 11 W output
power.
The board is equipped with a feedback loop that limits the output current. This feedback
loop senses the LED current over sense resistor R18 and a current mirror is used,
consisting of Q1 and Q2. The current level can be set using R20. The same feedback loop
is also used for overvoltage protection. If the LED voltage exceeds 23 V, a current will flow
through R19 and D9. The current through the optocoupler IC2 will pull down the
PWMLIMIT and BRIGHTNESS pin. The on-time is zero at a value below 400 mV. The
feedback loop has proportional action only, and the gain is critical because of phase shift
caused by the converter and C6. The relationship between PWMLIMIT and output current
is quadratic in nature. The resultant output current spread will be acceptable for most LED
applications.
The dimming range is detected by sensing the average rectified voltage. R4, R5 and R17
comprise a voltage divider, and C9 filters the resultant signal. The converter sets its duty
factor and converter frequency accordingly.
8).
All information provided in this document is subject to legal disclaimers.
Rev. 2 — 3 February 2011
SSL2101 12 W mains dimmable LED driver
UM10341
© NXP B.V. 2011. All rights reserved.
10 of 24