Supertex inc. CL8801 Sequential Linear LED Driver Features ►► ►► ►► ►► ►► ►► ►► ►► ►► ►► General Description Minimal component count (base config: CL8801 + 4 resistors + diode bridge) No magnetics, no capacitors Up to 7.5W output (13W w/ heat sink) >110Lm/W using efficient LEDs 85% electrical efficiency >0.95 power factor <30% THD line current Low conducted EMI w/o filters 85% LED luminous utilization Phase dimmer compatible with an RC network Applications ►► Fluorescent tube retrofit ►► Incandescent & CFL bulb replacement ►► General LED lighting The CL8801 is designed to drive a long string of inexpensive, low current LEDs directly from the AC mains. A basic driver circuit consists of the CL8801, four resistors, and a bridge rectifier. Two to four additional components are optional for various levels of transient protection. No capacitors, EMI filters, or power factor correction circuits are needed. A string of series/parallel LEDs is tapped at four locations. Four linear current regulators sink current at each tap and are sequentially turned on and off, tracking the input sine wave voltage. Voltage across each regulator is minimized when conducting, providing high efficiency. Output current at each tap is individually resistor-adjustable. Crossregulation, as the CL8801 switches from one regulator to the next, provides smooth transitions. The current waveform can be tailored to optimize for input voltage range, line/load regulation, output power/current, efficiency, power factor, THD, dimmer compatibility, and LED utilization. With the addition of an RC network, the driver is compatible with phase dimming. Typical Application Circuit transient protection AC Mains BIAS GND Doc.# DSFP-CL8801 D031914 TAP1 TAP2 TAP3 TAP4 SET3 SET4 CL8801 SET1 SET2 Supertex inc. www.supertex.com CL8801 CL8801K63-G M935 33-Lead (6x6) QFN 2000/Reel 33 GND 1 GND GND GND GND GND GND 4.0V Operating junction temperature -55ºC to +125ºC Storage temperature, TS -65°C to +150°C Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied. Continuous operation of the device at the absolute rating level may affect device reliability. All voltages are referenced to device ground. 33-Lead QFN (top view) Product Marking 8801 LLLLLL YYWW AAACCC Typical Thermal Resistance θja1 θjc2 33-Lead QFN 24OC/W 2.5OC/W NC VSET1–4 NC –0.5V to +320V SET4 VTAP2–4 NC –0.5V to +550V GND NC VBIAS, VTAP1 GND SET3 Value GND NC Parameter GND GND SET2 Absolute Maximum Ratings GND GND SET1 ESD Sensitive Device GND GND GND NC -G denotes a lead (Pb)-free / RoHS compliant package Package TAP4 490/Tray NC 33-Lead (6x6) QFN TAP3 CL8801K63-G NC Packing TAP2 Package Options BIAS Part Number TAP1 Pin Configuration Ordering Information L = Lot Number YY = Year Sealed WW = Week Sealed A = Assembler ID C = Country of Origin = “Green” Packaging 33-Lead QFN Notes: 1. 1.0oz Cu 4-layer board, 3x4” PCB with thermal pad and thermal via array. 2. Junction to exposed heat slug. Recommended Operating Conditions Sym IOUT VOUT VBIAS Parameter Output current Output voltage Min Typ Max TAP1 - - 60 TAP2 - - 90 TAP3 - - 200 TAP4 - - 200 TAP1 - - 400 TAP2-4 - - 300 TAP1-4 - - (1) - - 440 Applied BIAS voltage Units Conditions mA --- Non-conducting V Non-conducting Conducting V --- Note: (1) Voltage capability is determined by power dissipation (V × I). Doc.# DSFP-CL8801 D031914 2 Supertex inc. www.supertex.com CL8801 Electrical Characteristics (over recommended operating conditions at 25°C unless specified otherwise) Sym Parameter IBIAS BIAS pin input current ITAP(ON) ITAP(OFF) VREG Min Typ Max Units Conditions - 250 410 µA VBIAS = 170V TAP1 60 - - TAP2 90 - - TAP3 200 - - TAP4 200 - - - 0 10 SET1 - 3 1.80 2.00 2.20 SET4 1.89 2.10 2.31 Output current, on Output current, off Regulation voltage at SET pins VTAP1 = 30V, VSET1~4 = GND VTAP2 = 17V, VSET1~4 = GND mA VTAP3 = 17V, VSET1~4 = GND VTAP4 = 17V, VSET1~4 = GND µA TAP1 - 3, VBIAS = 170V V --- Output Current Thermal Characteristics Maximum Output Current 400 350 300 IOUT (mA) 250 Taps 3&4 200 150 100 Tap 2 50 Tap 1 0 -60 -40 -20 0 20 40 60 80 100 120 140 Temperature (°C) Simplified Block Diagram 120V transient protection AC Mains TAP1 BIAS TAP2 1 0 in reg TAP3 1 0 TAP4 1 0 GND CL8801 SET1 SET2 RSET1 Doc.# DSFP-CL8801 D031914 3 SET3 RSET2 SET4 RSET3 RSET4 Supertex inc. www.supertex.com CL8801 Overview board-to-board connections. Disadvantages include slightly reduced efficiency at high line, and additional heat load on the driver board. Designing a driver to meet particular requirements may be a difficult task considering the number of design variables (16): tap current (4), number of series-connected LEDs per segment (4), and the number of parallel-connected LEDs per segment (4). Manually selecting values will provide light, but the chosen values may be far from optimal in regards to efficiency, LED utilization, line regulation, etc. Phase Dimming As with any light load, the LED lamp might not draw enough current to assure proper dimmer operation. This is especially true for 230VAC dimmers. Triacs used in dimmers require a minimum latching current when triggered to place the triac in the latched-on state. Once latched, a minimum holding current is required to maintain the triac in the on state. Latching current is many times greater than the holding current, and is the main concern with dimmer compatibility. Contact your nearest Supertex Field Applications Engineer for design assistance. MathCAD and Excel worksheets are available by contacting [email protected]. In addition to configuring the driver, several circuits may be employed to increase reliability, performance, and cost. The following sections briefly describe these circuits. Higher latching current can be provided by a simple series RC network across the AC line. A short time constant provides a current spike at the turn-on edge. Transient Protection Since the driver circuits have no need for capacitors that could otherwise absorb transient energy, nor is there a need for EMI filters that would block transients, the full burden of transient protection is borne by the protection circuit. The two-stage approach in the following schematics provide 2.5kV protection, both pulse and ring per EN 61000-4-5 and EN 61000-4-12, six hits each. Less common is inadequate holding current. The minimum dimmer holding current is typically 10-20mA. Tap1 at 60mA (max) exceeds the minimum. AC Line 100 to 120VAC Transient Protection Transient Protection 500Ω Bridge Rectifier 100 - 200nF 22Ω AC Line Flicker 150VAC 10mm Twice per AC line cycle the line voltage crosses zero volts, during which time there is no light output. The circuit below can provide 5-10% valley fill. It has little effect on input current waveshape (THD, PF) and efficiency. 230VAC Transient Protection 22Ω 33Ω Power Boost Higher output power can be achieved by off-loading a portion of the power dissipation from the CL8801 to external FETs. The circuit below drops most of the tap voltage across the FETs, thereby shifting the bulk of the dissipation to the FET. AC Line 275VAC 10mm 440VDC 1.5kW Zener Substitution to LEDs Zeners may be substituted for LEDs in the bottom stages. The last 1 or 2 stages contribute little to light output - they are mainly to off-load the adjacent upstream regulator at high line voltages to minimize losses. Zener substitution advantages include minimizing unlit LEDs at low line for better light uniformity, better line regulation at high line, fewer LEDs for lower cost and less PCB area, and fewer 200kΩ TAP2 Doc.# DSFP-CL8801 D031914 4 to LEDs 15V TAP3 Supertex inc. www.supertex.com CL8801 Valley Fill Circuit Optional flicker reduction circuit (valley fill) CF1 RF1 10kΩ RF3 QF1 TAP1 RF2 150kΩ TAP2 TAP3 TAP4 CL8800 BIAS RS1 Doc.# DSFP-CL8801 D031914 QF2 DN3135 RS2 5 GND RS3 RS4 Supertex inc. www.supertex.com CL8801 Pin Description Pin # Pin Name Description 1-8 GND Circuit common (use for heat sink ground plane pass through). 9 SET1 Current sense for linear current regulators for each tap. Resistors on these pins sets the tap currents. 10 NC 11 SET2 12 NC 13 SET3 14 NC No internal connection. 15 NC No internal connection. 16 NC No internal connection. 17 SET4 18 NC 19 - 20 GND Circuit common (use for heat sink ground plane pass through). 21 GND Circuit common. Connect to bridge rectifier return (use for heat sink ground plane pass through). 22 - 26 GND Circuit common (use for heat sink ground plane pass through). 27 TAP4 Current regulator outputs. Connect to taps along the LED string. 28 NC 29 TAP3 30 NC 31 TAP2 Current regulator outputs. Connect to taps along the LED string. 32 TAP1 Current regulator outputs. Connect to taps along the LED string. 33 BIAS Provides bias for driver. Connect to rectified AC. Underside plate (GND) No internal connection. Current sense for linear current regulators for each tap. Resistors on these pins sets the tap currents. No internal connection. Current sense for linear current regulators for each tap. Resistors on these pins sets the tap currents. Current sense for linear current regulators for each tap. Resistors on these pins sets the tap currents. No internal connection. No internal connection. Current regulator outputs. Connect to taps along the LED string. No internal connection. For heatsinking purposes, it should be soldered to a 4.0cm2 exposed copper area. It should also be electrically connected to circuit common (GND). Note: The high voltage pins are located on one side of the package and are arranged from lowest voltage to highest. Pin-to-pin voltage gradients are minimized. Doc.# DSFP-CL8801 D031914 6 Supertex inc. www.supertex.com CL8801 33-Lead QFN Package Outline (K6) 6.00x6.00mm body, 1.00mm height (max), 0.50mm pitch D 33 D2 Note 4 0.70mm (min) 1 33 1 Note 1 (Index Area D/2 x E/2) e Note 1 (Index Area D/2 x E/2) E E2 b View B Top View Bottom View Note 3 θ A A3 L Seating Plane A1 L1 Note 2 Side View View B Notes: 1. A Pin 1 identifier must be located in the index area indicated. The Pin 1 identifier can be: a molded mark/identifier; an embedded metal marker; or a printed indicator. 2. Depending on the method of manufacturing, a maximum of 0.15mm pullback (L1) may be present. 3. The inner tip of the lead may be either rounded or square. 4. There will be an exposed DAP. A minimum of 0.7mm spacing will be maintained between the leads and the DAP. Symbol Dimension (mm) A A1 MIN 0.80 0.00 NOM 0.90 0.02 MAX 1.00 0.05 A3 0.20 REF b D D2 E E2 e 0.18 5.85 4.00 5.85 3.60 0.25 6.00 4.15 6.00 3.75 0.30 6.15 4.25 6.15 3.85 0.50 BSC L L1 θO 0.30 0.00 0 0.40 - - 0.50 0.15 14 Drawings not to scale. Supertex Doc. #: DSPD-33QFNK636X6P050, Version A021312. (The package drawings in this data sheet may not reflect the most current specifications. For the latest package outline information go to http://www.supertex.com/packaging.html.) Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//www.supertex.com) Supertex inc. ©2014 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited. Doc.# DSFP-CL8801 D031914 7 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com