LC5202S

LC5200 Series Off-Line LED Driver ICs Description ▪ Buck topology ▪ High input voltage: up to 250 V or 450 V, depending on product ▪ Constant current control circuit: ▫ Fixed off-time PWM constant current control, off-time adjustable by external components ▫ Externally adjustable output current by input voltage to REF pin ▪ External PWM signal: ▫ Dimming controlled by PWM signal to PWM pin ▫ Turning off LEDs by low input voltage to PWM pin ▪ Protection features: ▫ Undervoltage lockout protection (UVLO) ▫ Overcurrent protection (OCP) with latched shutdown ▫ Thermal shutdown protection (TSD) with auto restart The LC5200 series is a power IC, for non-isolated LED driver with commercial power supply applications, which includes both a main controller integrated circuit (MIC) and a power MOSFET. Its high voltage capability allows direct connection to a wide range of supply voltages ranging from 25 to 400 V (recommended). The LC5200 uses constant current mode to drive LEDs. The LC5200D series package is a fully molded DIP8 with pin 7 removed for greater isolation, and the LC5200S series package is an SOP8. ew Applications D es ig ns Features and Benefits rN ▪ LED lighting fixtures ▪ LED light bulbs en de d fo Packages DIP8 (LC5200D series) m m SOP8 (LC5200S series) R ec o Not to scale ot The product lineup for the LC5200 series provides the following options: N Part Number LC5202D LC5202S LC5205D Input Voltage, VBB Absolute Maximum (V) Recommended Operating Range* (V) 250 25 to 200 25 to 400 LC5203D 250 25 to 200 LC5210D 450 25 to 400 2.2 6 1.0 *Minimum input voltage of recommended range depends on LED output voltage. LC5200-DS, Rev. 6.0 RDS(ON)(max) (Ω) 0.5 450 LC5205S Output Current, IO (A) SANKEN ELECTRIC CO., LTD. Package DIP8 SOP8 DIP8 SOP8 1.3 DIP8 3 DIP8 LC5200 Series Off-Line LED Driver ICs Electrical Characteristics • The polarity value for current specifies a sink as "+ ," and a source as “−,” referencing the IC. ns • When pin numbers of the SOP8 differ from those of the DIP8, they are indicated in parentheses for the SOP8. Symbol Unit 250 V 450 V 250 V 450 V 0.5 A 1.0 A 2–8 −0.3 to VZ V 3–8 −0.3 to VREG + 0.3 V VSEN 4–8 −0.3 to 4 V Pins D VBB ew LC5205D LC5205S LC5210D VO rN LC5202D LC5202S LC5203D LC5205D LC5205S LC5210D LC5202D LC5202S LC5205D LC5205S Pulse width ≥ 1 μs 6–8 (7 – 8) 5–4 (5,6 – 4) Output Current1 de d Output Breakdown Voltage Notes LC5202D LC5202S LC5203D fo Main Power Supply Voltage Rating m Characteristic es ig Absolute Maximum Ratings Unless specifically noted, TA is 25°C 5–4 (5,6 – 4) en IO LC5203D LC5210D PWM Pin Voltage2 VPWM VREF m REF Pin Input Voltage ec o SEN Pin Voltage ot R Allowable Power Dissipation3,4 PD Pulse width ≥ 1 μs LC5202S LC5205S Mounted on Sanken evaluation board for the SOP8 – 0.85 W LC5202D LC5203D LC5205D LC5210D Mounted on Sanken evaluation board for the DIP8 – 1.73 W TA – −40 to 105 °C Storage Temperature Tstg – −40 to 150 °C Channel Temperature TJ – 150 °C N Operating Ambient Temperature 1The Output Current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do not exceed the specified junction temperature, TJ . 2V here is the breakdown voltage of the Zener diode that is internally connected between the PWM pin and GND: V = 6.3 V (typ). Maximum input Z Z current is 1 mA. 3Allowable Power Dissipation, P , depends on PWB circuit trace layout. D 4Refer to the T versus P curve. A D LC5200-DS, Rev. 6.0 SANKEN ELECTRIC CO., LTD. 2 LC5200 Series Off-Line LED Driver ICs 2 PD = 1.73 W Mounted on the corresponding Sanken evaluation board 1 PD = 0.85 W 0.5 0 0 25 50 75 D SOP8 RθJA = 147°C/W es ig DIP8 RθJA = 72°C/W ns 1.5 ew Maximum Allowable Power Dissipation PD (W) TA versus PD Curve 100 125 150 Recommended Operating Conditions* Symbol en Characteristic de d fo rN Ambient Temperature, TA (°C) m LC5202D LC5202S LC5203D VBB ec o m Main Power Supply Voltage IO(AVG) ot R Average Output Current REF Pin Input Voltage N Case Temperature LC5205D LC5205S LC5210D Notes Minimum input voltage of the recommended range depends on the LED output voltage. LC5202D LC5202S LC5205D LC5205S Pins TC Normal operation Center of branded side, TJ ≤ 150°C Max. Unit 25 200 V 25 400 V – 0.4 A – 0.8 A 6–8 (7 – 8) 5–4 (5,6 – 4) LC5203D LC5210D VREF Min. 3–8 – 0.8 V – – 105 °C *Recommended operating conditions means operating conditions that maintain normal device functions as shown in the Electrical Characteristics table. LC5200-DS, Rev. 6.0 SANKEN ELECTRIC CO., LTD. 3 LC5200 Series Off-Line LED Driver ICs Electrical Characteristics Unless specifically noted, TA is 25°C, VBB = 140 V Symbol Test Conditions Max. Unit Output off 6–8 (7 – 8) ― 0.8 1.2 mA IBB Normal operation 6–8 (7 – 8) ― 2 ― mA 250 ― ― V VF ID = 0.5 A LC5203D ID = 1.0 A LC5205D LC5205S ID = 0.5 A LC5210D ID = 1.0 A LC5202D LC5202S IF = 0.5 A LC5203D IF = 1.0 A LC5205D LC5205S IF = 0.5 A UVLO Threshold (Turn on) VUVLO(ON) UVLO Threshold (Turn off) VUVLO(OFF) VREG REG Pin Output Current IREG 4–5 (4 – 5,6) IF = 1.0 A ― ― V ― 1.2 2.2 Ω ― 0.7 1.3 Ω ― 3.5 6 Ω ― 1.7 3 Ω ― 0.8 1.0 V ― 0.75 1.2 V ― 0.8 0.9 V ― 0.88 1.0 V 6–8 (7 – 8) ― 14 ― V 6–8 (7 – 8) ― 13 ― V IREG = –0.1 mA 1−8 11.5 12 12.5 V VREG = 11 V 1−8 ― ― −2 mA VBB pin VBB pin m m REG Pin Output Voltage 5–4 (5,6 – 4) de LC5210D es ig LC5202D LC5202S 450 D RDS(ON) ID = 1 mA ew LC5205D LC5205S LC5210D fo V(BR)DSS 5–4 (5,6 – 4) rN LC5202D LC5202S LC5203D en Body Diode Forward Voltage Typ. d Output MOSFET On-Resistance Min. IBBS Power Supply Current Output MOSFET Breakdown Voltage Pins ns Characteristic VREF 3−8 0 ― 1 V IREF 3−8 −10 ― 10 μA Current Control Detection Voltage VSEN 4−8 VREF − 0.03 VREF VREF + 0.03 V OCP Detection Voltage VOCP 4−8 ― 3 ― V ISEN 4−8 −10 ― 10 μA REF Pin Input Voltage R SEN Pin Current ec o REF Pin Input Current tBLK PWM Operation Frequency fPWM N ot PWM Blanking Time Duty cycle = 50% ― ― 400 ― ns 2−8 ― ― 200 kHz Output MOSFET Rise Time tr IO = 0.4 A 5–4 (5,6 – 4) ― 20 ― ns Output MOSFET Fall Time tf IO = 0.4 A 5–4 (5,6 – 4) ― 50 ― ns ― °C Thermal Shutdown Threshold TTSD Temperature of Control Part ― ― 150 Thermal Shutdown Hysteresis TTSD(HYS) Temperature of Control Part ― ― 55 ― °C ― ― ― 72 °C/W ― ― ― 147 °C/W LC52xxD Thermal Resistance LC5200-DS, Rev. 6.0 RθJA LC52xxS Mounted on the Sanken evaluation board; the thermal resistance between MOSFET and ambient temperature SANKEN ELECTRIC CO., LTD. 4 LC5200 Series Off-Line LED Driver ICs Pin List Table Number 8 GND REG 1 LC52xxD (DIP8) LC52xxS (SOP8) REG 1 1 Internal regulator supply, provides current to internal and external circuits; connect a 0.1 μF bypass capacitor between this pin and GND PWM 2 2 Input for PWM control; to use internal PWM, connect a CR (capacitor and resistor) for setting off-time; to use external PWM, connect to PWM signal source REF 3 3 Reference voltage input; sets peak output current of OUT pin (internal power MOSFET) for internal PWM control by REF pin voltage SEN 4 4 Output current detection; detects peak output current for internal PWM control, and detects overcurrent for OCP; connect to current detection resistor, RS OUT 5 5, 6 VBB 6 7 – 7 GND 8 REG 1 8 GND PWM 2 7 VBB REF 3 6 OUT SEN 4 5 OUT Drain of internal power MOSFET Supply voltage; provides power to internal circuits through internal regulator LC5200D DIP8 pin removed to increase creepage distance between high votlage pin and low voltage pin (Note: apply user's criteria for creepage distance when using LC5200S SOP8) 8 Ground pin en de d SOP8 LC5200S Series D DIP8 LC5200D Series ew 5 OUT rN SEN 4 fo 6 VBB es ig PWM 2 REF 3 Function ns Pin-out Diagrams Name m Functional Block Diagram m 6 (7) VBB Regulator PWM 2 REF 3 Current Control ot R ec o REG 1 Control IC UVLO Logic TSD OUT 5 (5,6) Gate Driver N OCP SEN 4 8 GND When pin numbers of the SOP8 differ from those of the DIP8, they are indicated in parentheses for the SOP8 LC5200-DS, Rev. 6.0 SANKEN ELECTRIC CO., LTD. 5 LC5200 Series Off-Line LED Driver ICs Internal Circuit Descriptions Undervoltage Lockout (UVLO) ns Note: The OCP function is activated only when the SEN pin voltage, VSEN , reaches VOCP by excessive output current flowing to RS . Therefore if the output current is restricted to less than its target value, for example by current limitations of the inductor, even though the LEDs are shorted, OCP would not be activated. m Thermal Shutdown (TSD) m en de d This continually monitors whether the output voltage from the Regulator function is normal, and prevents abnormal operation resulting from low input voltage. When the VBB pin voltage is lower than the UVLO threshold (Turn-off), VUVLO(OFF) , the IC reverts to the state before startup. In addition, this function is available during power-on reset, for releasing latched shutdowns resulting from operation of protection functions. rN The output current is controlled constant in internal PWM mode, by comparing the REF pin voltage with the SEN pin voltage. fo Current Control Overcurrent Protection (OCP) The drain current is detected by the current detection resistor, RS . When the SEN pin voltage, VSEN , reaches the OCP detection voltage, VOCP , or more, the OCP function is activated, and thus the output of the OUT pin turns off, in latch mode. To release latch mode, cycling power to the IC (that is, the VBB pin voltage falling down to VUVLO(OFF) and then rising to VUVLO(ON)) is required. ew This regulator steps-down from the supply voltage, VBB , to 12 V, and provides power to internal circuits and external devices. A ceramic capacitor of 0.1 μF should be connected close to the REG pin to stabilize operation because some pulse currents flow through the gate capacitor when charging the internal power MOSFET. es ig Regulator Because this circuit is in the Control Part, there is a delay before temperature increases in the internal power MOSFET are conducted to the Control Part. If the temperature of the power MOSFET increases rapidly, the power MOSFET may be damaged before TSD is activated. Therefore, it is necessary design the application well to protect against this. D This section describes the functions displayed in the Functional Block diagram. Gate Driver Operation Gate driver for internal power MOSFET. Internal Power MOSFET An internal power MOSFET for LED driving is incorporated in the IC series, according to the individual product ratings for current and voltage. N ot R ec o This continually monitors the chip temperature of the Control Part. When the temperature increases to TTSD or higher, the output of the OUT pin turns off to prevent damage from abnormally high temperature. After TSD operation, when the temperature decreases to TTSD minus TTSD(HYS) or lower, or after cycling power to the IC (that is, the VBB pin voltage falling down to VUVLO(OFF) and then rising to VUVLO(ON) ), the IC returns to normal operation. Logic This controls the enabling and disabling of the output of the OUT pin according to signals from the current control circuit and/or the various protection circuits. The output is enabled only when the operation is normal and the current control circuit outputs the on-signal for the OUT pin. LC5200-DS, Rev. 6.0 SANKEN ELECTRIC CO., LTD. 6 LC5200 Series Off-Line LED Driver ICs ns Typical Application Circuit U1 CIN Line Filter REG VBB C2 LC5200 REF PWM OUT SEN CPWM GND VLED L1 RS rN R2 C1 D RPWM R1 D1 ew AC Input es ig VIN N ot R ec o m m en de d fo Figure 1. Typical application circuit example for a buck configuration; for component values, see Application Information section LC5200-DS, Rev. 6.0 SANKEN ELECTRIC CO., LTD. 7 LC5200 Series Off-Line LED Driver ICs Package Diagrams DIP8 1 4 es ig 5 ew rN +0.3 1.52 -0.05 (7.6 TYP) 3.3 ±0.2 m m en 7.5 ±0.5 de 4.2 ±0.3 d 3.4 ±0.1 fo 1.0 +0.3 -0.05 D 6.5 ±0.2 8 ns 9.4 ±0.3 0.2 5 + 0. - 0.01 5 ０～１５° ０～１５° ec o 2.54 TYP 0.5 ±0.1 R 0.89 TYP ot Unit： mm N 8 LC52xx SK YMW XXXX Pb-free. Device composition compliant with the RoHS directive. LC5200-DS, Rev. 6.0 1 SANKEN ELECTRIC CO., LTD. Part Number Lot Number Y is the last digit of the year (0 to 9) M is the month (1 to 9, O, N, or D) W is week code (1 to 3) Sanken Control Number 8 LC5200 Series Off-Line LED Driver ICs SOP8 5.2 ±0.3 1 rN ew D 6.2 ±0.3 es ig ns 5 4.4 ±0.2 8 4 0 to 10° fo 0.695 TYP m en +0.1 0.15 –0.05 de 1.5 ±0.1 d 5.25 ±0.3 ec o 0.05 ±0.05 m 1.27±0.05 0.10 0.4±0.1 ot R 0.12 M 0.4±0.2 N Unit： mm 8 LC52xx SK YMW Pb-free. Device composition compliant with the RoHS directive. XXXX 1 LC5200-DS, Rev. 6.0 Part Number Lot Number Y is the last digit of the year (0 to 9) M is the month (1 to 9, O, N, or D) W is week code (1 to 3) Sanken Control Number SANKEN ELECTRIC CO., LTD. 9 LC5200 Series Off-Line LED Driver ICs Functional Description • All of the parameter values used in these descriptions are typical values, unless they are specified as minimum or maximum. Internal PWM Control Circuit Figure 3 shows the internal PWM control circuit, and figure 4 shows the timing diagram of that circuit. When the power MOSFET turns on, both the load current and VSEN across the current detection resistor RS increase. REG Turning-Off Period The output current through the LED string is equivalent to the current through the detection resistor, RS, and thus the LED current is detected at the SEN pin as a voltage. When the SEN pin voltage, VSEN, is equal to the REF pin voltage, VREF, the internal power MOSFET turns off. RPWM rN fo Comp1 S + Q R 6V REF + Comp2 VREF Blank Pulse - I O d de en m ION - PWM CPWM LC5200 2V ew 3V PWM Off-Time Period When the internal power MOSFET turns off, the current recirculation diode, D1, is forward biased by the back electromotive force (BEMF) in the inductor, L1, and D1 turns on. Then the energy stored in L1 during PWM on-time flows through the recirculation path shown as IOFF in figure 2. VIN D es ig PWM On-Time Period At startup, or during normal operation before the output current through the LED string reaches the target current level, the internal power MOSFET turns on and the output current flows through the ION path shown in figure 2. Turning-On Period After the fixed off-time, tOFF , the internal power MOSFET turns on again, and the PWM on-time period repeats. The cycle is shown in figure 2 panel B. ns PMW Current Control (Buck Converter) • The polarity value for current specifies a sink as "+ ," and a source as “−,” referencing the IC. OUT To LED load Logic Gate Driver SEN RS GND D1 V LED ec o (A) LC5200 LED m IOFF OUT R MOSFET SEN ot GND L1 LED Current ILED RS VREF VSEN LED current ILED (B) ION I OFF I ON I OFF ION Comp2 DS EN DS EN tBLK IOFF DS t BLK Negative IN OT Comp OUT ON OFF tOFF Figure 2. Current Control of Buck Converter LC5200-DS, Rev. 6.0 IOFF Comp1 VREF VSEN MOSFET ION Comp2 OUT N GND VSEN Figure 3. Current Control Circuit OFF MOSFET ON V PWM ON OFF ON A t OFF B Figure 4. Current Control Circuit Timing Chart SANKEN ELECTRIC CO., LTD. 10 LC5200 Series Off-Line LED Driver ICs D VREF VREG × R2 = RS RS × ( R1 + R2 ) (1) ew IPEAK = The LC5200 series allows external adjustment of the current flowing through the LED string, using either of the following methods: rN When VPWM increases to more than 3 V, the fixed off-time expires and the power MOSFET turns on. After that, the operation reverts to the initial state, shown as point B in figure 4. • Adjusting the analog voltage on the REF pin (figure 6A) • Inputting the analog voltage integrated PWM signal through a low pass filter, LPF, to the REF pin (figure 6B) fo VSEN is detected in the on-time period, except during the PWM blanking time, tBLK , in order to prevent malfunction. Using Internal PWM Dimming The LC5200 series has a built-in PWM constant current control circuit, and thus can achieve a constant current drive system for the LED string, while requiring few external components. The peak output current, IPEAK , for driving the LED string is calculated as follows: es ig After a certain period, when the PWM pin voltage, VPWM , decreases to less than 2 V, the comparator for the off-time, Comp1, inverts and the Q output of the RS flip-flop is set. Then the MOS switch for discharging CPWM turns off, and CPWM is charged by the REF pin voltage through RPWM (connected between the REF and PWM pins). Current Value Setting for Dimming Control The LC5200 series allows constant current control using the internal PWM control, an external PWM signal, or a combination of both of them. ns Comp2 compares VSEN and VREF , and when VREF < VSEN , Comp2 inverts its output (see point A in figure 4). This resets the output Q of the RS flip-flop. After a turn-off signal is transmitted from the AND gate to the logic, to the gate driver, and finally to the internal power MOSFET, the power MOSFET turns off. At the same time, an internal MOS switch, connected to the PWM pin, turns on, and CPWM is discharged. However, the dimming control by adjusting the REF pin voltage can not set the output current to zero. When controlling to zero current, an external signal and external circuit are needed to set the PWM pin voltage to low. m en de d The fixed off-time is determined by RPWM and CPWM. Figure 5 shows PWM off-time curves based on various values of RPWM and CPWM . The recommended value for RPWM is 560 kΩ, and that for CPWM is 220 pF. In addition, the proper values for RPWM and CPWM are changeable according the load conditions of the LEDs used, and the value of RPWM also affects the losses in the internal regulator directly. It is necessary to pay attention to these factors. REG RPWM LC5200 C1 ec o m R1 10 R R2 C2 0 pF (A) Analog Control = 220 pF 0 pF C PWM = 47 pF C PWM = 22 pF C PWM = 10 pF REG LPF RLPF 560 CLPF 600 800 LC5200 REF PWM GND CPWM SEN RS 1000 (B) Integrated PWM Control RPWM Value for Setting Off-Time (Ω) Figure 5. PWM Off-Time versus RPWM Value, for Various Values of CPWM LC5200-DS, Rev. 6.0 RPWM PWM Signal 2 400 SEN RS C PWM = 10 5 1 200 GND CPWM C PWM = 47 C PWM ot 20 N Internal PWM Off-Time, tOFF (μs) 50 REF PWM Figure 6. Dimming Application Circuits with Internal PWM Control SANKEN ELECTRIC CO., LTD. 11 LC5200 Series Off-Line LED Driver ICs PWM Signal OUT GND SEN en REF PWM m RS OUT Pin ns es ig RPWM LC5200 R1 REF MOS Switch PWM Signal VBB OUT PWM GND CPWM SEN R2 RS PWM Pin Signal LED Current Control Off L Internal PWM current control On H LED current off R ec o L H REG Truth Table for Combined Internal and External PWM m Truth Table for External PWM PWM Pin Signal D de LC5200 100 kΩ As shown in figure 8, the circuit has an added external MOS switch, and when the PWM pin signal goes low, the internal PWM current control is activated. d VBB REG The narrower the duty cycle of the external PWM signal is, the higher the average LED output current is. At a 100% duty cycle, the LED output current is 0 A. The timing diagram is shown in figure 9. fo On the internal circuit of the PWM pin, there is a comparator with hysteresis. When the input signal on the PWM pin is 3 V, the comparator turns on the OUT pin, and when the input signal is 2 V, the comparator turns off the OUT pin. Because the internal circuit of the PWM pin has a built-in Zener diode of 6.3 V (typ) for protection, the PWM pin voltage is compatible with 5 V CMOS logic level. Using Both Internal and External PWM Dimming This configuration combines the two configurations described above: the internal PWM control circuit determines the limitation of the peak output current flowing through the LED string, and the external PWM circuit controls the average current. This configuration is effective for a low frequency external PWM range, 200 to 500 Hz. The application circuit is shown in figure 8. ew As shown in figure 7, CPWM and RPWM are removed, and then the PWM signal is directly input to the PWM pin. The REF pin must be pulled up to the REG pin. When the SEN pin voltage, VSEN, reaches the OCP detection voltage, VOCP, or more, the OCP function is activated. rN Using External PWM Dimming Using an external PWM signal allows applying the LC5200 series as a high voltage power switch. In this configuration, the output of the OUT pin turns on and off according to a logic signal input to the PWM pin. Because this control is not activated by the internal PWM current control circuit, an external current control circuit is needed. The frequency of the input PWM signal is recommended to be in the range 20 to 200 kHz. Figure 8. Dimming Application Circuit with Combined Internal and External PWM Control N ot Figure 7. Dimming Application Circuit with External PWM Control PWM VPWM LED ILED IC Internal PWM OFF Figure 9. Timing for Combined Internal and External PWM Operation LC5200-DS, Rev. 6.0 SANKEN ELECTRIC CO., LTD. 12 LC5200 Series Off-Line LED Driver ICs Application Information ns es ig ew D In actual operation, L1 should be rated such that it is not saturated by the peak of the ripple current. If the inductor becomes saturated by an unexpectedly high surge current flow, the LEDs and the IC could be damaged. D1 This is a free-wheeling diode for recirculation of the output current. The energy stored during the PWM on-time period is provided to the LEDs through this diode during the off-time period. The withstand voltage and the recovery time, tRR , should be considered. m en de d LEDs The relationship between the LED ratings and the output current ratings of the IC should be considered. In a buck configuration, the total forward voltage drop, VLED , of the LEDs in series L1 This is an inductor for smoothing output current. When the inductance value of L1 is relatively higher, the LED ripple current is lower, and thus current stability is improved. Normally, an L1 value of 0.5 to 10 mH is assumed. fo External Component Selection The following recommendations should be observed when selecting components for use with the LC5200 series. should be less than the VBB pin voltage, VBB , because the LEDs would be turned off if VLED were more than VBB . Normally, a VLED of 9 to 60 V is assumed. rN Typical Application Components The typical application circuit for a buck configuration, shown in figure 1, is an example for a basic peripheral circuit. Table 1 provides reference specifications for the typical application circuit in figure 1, listing parts as examples for the sole purpose of reference for the initial use of the IC. The specifications are for typical values, and do not take into consideration application usage conditions such as PCB layout, LED types, or circuit noise. It is necessary to take account of such factors fully while designing the application, and component selection should be validated by operation in the actual application. m Table 1. Reference Specification of the Typical Application Circuit Symbol L1 Part Type Reference Values and Rating LED – R LED ec o Input voltage: 100 VAC, LED output voltage: 5 LEDs in series (about 15 to 18 V total), LED peak output current: 0.35 A 1 mH / 1 A D1 SJPD-L5 CIN Capacitor C1 Capacitor ot Inductor Fast Recovery Rectifier Diode N Description User-defined Up to 4.7 μF / 450 V 0.1 μF / 25 V Choke coil for smoothing current Free-wheeling diode for recirculation Main supply source filtering capacitor Internal regulator stabilizing capacitor C2 Capacitor 0.1 μF / 25 V RPWM Resistor 560 kΩ / 1/8 W PWM off-time setting resistor for internal PWM control CPWM Capacitor 220 pF / 25 V PWM off-time setting capacitor for internal PWM control R1 Resistor 680 kΩ / 1/8 W Resistor for setting peak output current on OUT pin R2 Resistor 20 kΩ / 1/ W 8 Resistor for setting peak output current on OUT pin RS Resistor 1.0 Ω / 1 W LC5200-DS, Rev. 6.0 REF pin voltage stabilizing capacitor Resistor for output current detection SANKEN ELECTRIC CO., LTD. 13 LC5200 Series Off-Line LED Driver ICs ns VREF VREG × R2 = RS RS × ( R1 + R2 ) es ig For example, to set IPEAK to 0.35 A, assuming a REG pin voltage, VREG , of 12 V, and resistances for R1 of 680 kΩ, R2 of 20 kΩ, and RS of 1 Ω: IPEAK = 12 (V) × 20 (kΩ) 1 (Ω) × ( 680 (kΩ) × 20 (kΩ) ) = 0.343 A In actual operation, the current value is higher than that calculated by the above equation because there is some propagation delay in internal circuit. Especially when the input voltage is high and the inductance value is low, the di/dt slope of the current is high, and the actual current value is much higher than the calculated current value. The current flowing to R1 and R2 affects the losses in the internal regulator directly. Therefore it is recommended to select R1 and R2 such that 500 kΩ < R1 + R2 , in order to restrict current as much as possible. d fo Note: If the lower peak of the ripple voltage of VIN is allowed to fall below the UVLO Threshold (Turn off), VUVLO(OFF) , or if the output voltage is less than VLED , the LEDs are turned off. Thus it is necessary to take account of the value of CIN . IPEAK = D The IC is capable of operation, with VIN full-wave rectification, with an input capacitor rated as low as approximately 1000 pF, instead of with an electrolytic capacitor. By allowing configuration without an electrolytic capacitor, the IC enhances power supply system operational life, and reduces system size and cost. These resistors determine the peak output current, IPEAK , flowing to the LEDs. The peak current value can be calculated as follows: ew CIN This is an input smoothing capacitor. When the capacitance value of CIN is relatively higher, the input and output ripple voltages are lower. However, given a certain capacitance level, the greater the output power is, the greater the ripple voltages are. Thus it is necessary to select the value according to the output power. R1, R2, and RS rN If a diode with a long tRR is selected, surge current may flow into the OUT pin when the internal power MOSFET turns on. If this were to occur, it would cause increased noise, potentially resulting in malfunction due to the noise, and decreased efficiency. ec o m m en de C1 This is a capacitor for stabilizing the internal regulator. It is required to provide the charge current for charging the gate of the internal power MOSFET, and to maintain a stable voltage. Normally, a ceramic capacitor of 0.1 μF is used. A too-low value causes decreased switching speed and malfunctions. A too-high value causes a longer startup time because a long charging time for this capacitor delays startup for the power supply. These factors should be carefully evaluated. RPWM and CPWM Refer to the PWM Current Control (Buck Converter) section. N ot R The capacitor should be placed as close to the IC as possible. It is recommended that the detection resistor, RS , have an allowable power dissipation that is twice to three times as much as the loss in RS as margin, because the output current flows to it when the internal power MOSFET turns on, and the loss may be comparatively large. LC5200-DS, Rev. 6.0 SANKEN ELECTRIC CO., LTD. 14 LC5200 Series Off-Line LED Driver ICs fo rN ew D es ig ns Electrostatic Discharge • When handling the products, the operator must be grounded. Grounded wrist straps worn should have at least 1 MΩ of resistance from the operator to ground to prevent shock hazard, and it should be placed near the operator. • Workbenches where the products are handled should be grounded and be provided with conductive table and floor mats. • When using measuring equipment such as a curve tracer, the equipment should be grounded. • When soldering the products, the head of soldering irons or the solder bath must be grounded in order to prevent leak voltages generated by them from being applied to the products. • The products should always be stored and transported in Sanken shipping containers or conductive containers, or be wrapped in aluminum foil. N ot R ec o m m en de d Because reliability can be affected adversely by improper storage environments and handling methods, please observe the following cautions. Cautions for Storage • Ensure that storage conditions comply with the standard temperature (5°C to 35°C) and the standard relative humidity (around 40% to 75%); avoid storage locations that experience extreme changes in temperature or humidity. • Avoid locations where dust or harmful gases are present and avoid direct sunlight. • Reinspect for rust on leads and solderability of the products that have been stored for a long time. Cautions for Testing and Handling When tests are carried out during inspection testing and other standard test periods, protect the products from power surges from the testing device, shorts between the product pins, and wrong connections. Ensure all test parameters are within the ratings specified by Sanken for the products. Soldering • When soldering the products, please be sure to minimize the working time, within the following limits: ▫ DIP8 Flow soldering: 260±5°C 10±1 s (2 times) Soldering iron: 380±10°C 3.5±0.5 s (1 time) Soldering should be at a distance of at least 1.5 mm from the body of the products. ▫ SOP8 Reflow soldering: 180°C 90±30 s for preheating 250°C 10±1 s (260°C peak, 2 times) for solder heating Soldering iron: 380±10°C 3.5±0.5 s (1 time) Note: Flow soldering must not be used. LC5200-DS, Rev. 6.0 SANKEN ELECTRIC CO., LTD. 15 LC5200 Series D es ig ns Off-Line LED Driver ICs ew • The contents in this document are subject to changes, for improvement and other purposes, without notice. Make sure that this is the latest revision of the document before use. rN • Application and operation examples described in this document are quoted for the sole purpose of reference for the use of the products herein and Sanken can assume no responsibility for any infringement of industrial property rights, intellectual property rights or any other rights of Sanken or any third party which may result from its use. d fo • Although Sanken undertakes to enhance the quality and reliability of its products, the occurrence of failure and defect of semiconductor products at a certain rate is inevitable. Users of Sanken products are requested to take, at their own risk, preventative measures including safety design of the equipment or systems against any possible injury, death, fires or damages to the society due to device failure or malfunction. de • Sanken products listed in this document are designed and intended for the use as components in general purpose electronic equipment or apparatus (home appliances, office equipment, telecommunication equipment, measuring equipment, etc.). m en When considering the use of Sanken products in the applications where higher reliability is required (transportation equipment and its control systems, traffic signal control systems or equipment, fire/crime alarm systems, various safety devices, etc.), and whenever long life expectancy is required even in general purpose electronic equipment or apparatus, please contact your nearest Sanken sales representative to discuss, prior to the use of the products herein. ec o m The use of Sanken products without the written consent of Sanken in the applications where extremely high reliability is required (aerospace equipment, nuclear power control systems, life support systems, etc.) is strictly prohibited. ot R • In the case that you use Sanken products or design your products by using Sanken products, the reliability largely depends on the degree of derating to be made to the rated values. Derating may be interpreted as a case that an operation range is set by derating the load from each rated value or surge voltage or noise is considered for derating in order to assure or improve the reliability. In general, derating factors include electric stresses such as electric voltage, electric current, electric power etc., environmental stresses such as ambient temperature, humidity etc. and thermal stress caused due to self-heating of semiconductor products. For these stresses, instantaneous values, maximum values and minimum values must be taken into consideration. N In addition, it should be noted that since power devices or IC's including power devices have large self-heating value, the degree of derating of junction temperature affects the reliability significantly. • When using the products specified herein by either (i) combining other products or materials therewith or (ii) physically, chemically or otherwise processing or treating the products, please duly consider all possible risks that may result from all such uses in advance and proceed therewith at your own responsibility. • Anti radioactive ray design is not considered for the products listed herein. • Sanken assumes no responsibility for any troubles, such as dropping products caused during transportation out of Sanken's distribution network. • The contents in this document must not be transcribed or copied without Sanken's written consent. LC5200-DS, Rev. 6.0 SANKEN ELECTRIC CO., LTD. 16