NXP’s SSL4101T is the GreenChip III+ third-generation green switching power supply controller. It integrates PFC and flyback controllers. The built-in green function can make it highly efficient at all power levels. SSL4101T is a multi-chip module (MCM), Contains two chips, suitable for 70 V (AC) to 305 V (AC) voltage, few external components, and that has a variety of protection features, suitable for all LED lighting applications between 10W-300W. This article introduces SSL4101T Main features and advantages, block diagram, typical configuration diagram and application Circuit diagram, 48 V/150 W demo board (v.1.1) main features and indicators, circuit diagram, bill of materials and PCB layout diagram.
The GreenChip III+ is the third generation of green Switched Mode Power Supply (SMPS)controller ICs. The SSL4101T combines a controller for Power Factor Correction (PFC) and a flyback controller. Its high level of integration allows the design of a cost-effective LED lighting application power supply with a very low number of external components.
The special built-in green functions provide high efficiency at all power levels. This applies to quasi-resonant operation at high power levels, quasi-resonant operation with valley skipping, as well as to reduced frequency operation at lower power levels. At low power levels, the PFC switches off to maintain high efficiency.
During low power conditions, the flyback controller switches to frequency reduction mode and limits the peak current to 25% of its maximum value. This will ensure high efficiency at low power and good standby power performance while minimizing audible noise from the transformer.
The SSL4101T is a MultiChip Module, (MCM), containing two chips. The proprietary high voltage BCD800 process which makes direct start-up possible from the rectified universal mains voltage in an effective and green way. The second low voltage SiIlicon On Insulator(SIO ) is used for accurate, high speed protection functions and control.
The SSL4101T enables extremely efficient and reliable LED lighting application power supplies with power requirements from 10 W to 300 W, to be designed easily and with a minimum number of external components.
The new SSL4101T allows a typical 150 W LED lighting application power supply(universal input, 48 V (DC) output, TEA1761T on the secondary side for Synchronous Rectification) to achieve the following performances at full load:
• 120 V (AC): 92% efficiency, 0.998 PF, 5.8% THD, <190 mW standby power
• 277 V (AC): 94% efficiency, 0.978 PF, 9% THD, <350 mW standby power
The SSL4101T enables LED lighting application power supplies to achieve the industry standard of <20% THD for the input current at full load and all nominal input voltages: 100 V (AC), 120 V (AC), 230 V (AC), 240 V (AC) and 277 V (AC).
• Extremely low input power in Standby mode eliminates the need for an additional housekeeping power supply to power the lighting controllers/dimmers.
• Using SSL4101T, a low power controller (< 50 mW) can be driven directly by the LED lighting application power supply's output while maintaining the input power in Standby mode below the maximum of 0.5 W.
• Extremely high-efficiency can be achieved in LED lighting application power supplies using the SSL4101T (between 92% to 94 %). This enables the power supply to operate reliably in enclosed spaces with very little cooling (which is typical for SSL applications).
Main features and advantages of SSL4101T:
Distinctive features
Integrated PFC and flyback controller.
True universal mains supply operation: 70 V (AC) to 305 V (AC).
High level of integration, resulting in a very low external component count and a cost-effective design.
Green features
On-chip start-up current source.
PFC green features
Valley/zero voltage switching for minimum switching losses (NXP Semiconductors patented).
Frequency limitation to reduce switching losses.
PFC is switched off when a low load is detected at the flyback output.
Flyback green features
Valley switching for minimum switching losses (NXP Semiconductors patented).
Frequency reduction with fixed minimum peak current at low power operation to maintain high efficiency at low output power levels.
Protection features
Safe restart mode for system fault conditions.
Continuous mode protection by means of demagnetization detection for both converters (NXP Semiconductors patented).
UnderVoltage Protection (UVP) (foldback during overload).
Accurate OverVoltage Protection (OVP) for both converters (adjustable for flyback converter).
Open control loop protection for both converters. The open loop protection on the flyback converter is safe restart.
IC OverTemperature Protection (OTP).
Low and adjustable OverCurrent Protection (OCP) trip level for both converters.
General purpose input for latched protection, eg to be used for system
OverTemperature Protection (OTP).
SSL4101T application:
The device can be used in all LED lighting applications that require a very efficient, low THD, high PF, true universal input voltage and cost-effective power supply solution between 10 W and 300 W.

Figure 1. SSL4101T block diagram

Figure 2. Typical configuration diagram of SSL4101T

Figure 3. Typical application circuit diagram of SSL4101T
48 V/150 W demo board with SSL4101 (v.1.1)
The board can be connected to a mains voltage between 108 V and 305 V. A different mains voltage range can be selected with minor modifications. The output connected to the LEDs is designed for reinforced isolation from the mains. The demo board is designed to meet UL1950, UL8750 and EN61347 but was not submitted for safety compliance.
Touching the reference board during operation must be avoided at all times.

Figure 4. Outline drawing of SSL4101 demo board
SSL4101 demo board indicators:


Figure 5. Circuit diagram of SSL4101 demo board
SSL4101 demo board material list:




Figure 6. The PCB layout of the SSL4101 demo board
For details, see:
http://www.nxp.com/documents/data_sheet/SSL4101T.pdf
and
http://www.nxp.com/documents/user_manual/UM10469.pdf