L6585DE Combo IC for PFC and ballast control Features ■ ■ PFC section – transition mode PFC with over-current protection – over-voltage protection – feedback disconnection – under-voltage lockout – PFC choke saturation detection – THD optimizer SO-20 – programmable and precise end-of-life protection compliant with all ballast configurations – smart hard switching detection – fast ignition voltage control with choke saturation detection – half-bridge over-current control Half-bridge section – preheating
Contents L6585DE Contents 1 2 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1 Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2 Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1 Maximum ratings .
L6585DE Contents 6.8 Choke saturation protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 8 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pin settings L6585DE 1 Pin settings 1.1 Connection Figure 2. 1.2 Functions Table 1. Pin functions Pin n. Name Function 1 OSC An external capacitor to ground fixes the half-bridge switching frequency with a ± 3 % precision. RF Voltage reference capable of sourcing up to 240 µA. The current sunk from this pin fixes the switching frequency of the half-bridge for each operating state.
L6585DE Pin settings Table 1. Pin n. 4 Pin functions (continued) Name Function Tch Pin for setting the preheating time and protection intervention. Connect an RC parallel network (Rd and Cd) to ground. Preheating: the Cd is charged by an internal current generator. When the pin voltage reaches 4.63 V the generator is disabled and the capacitor discharges because of Rd. Once the voltage drops below 1.5 V, the preheating finishes, the ignition phase starts and the RdCd is pulled to ground.
Pin settings L6585DE Table 1. Pin n. Name Function 13 PFG PFC gate driver output. The totem pole output stage is able to drive power MOSFETs with a peak current of 300 mA source and 600 mA sink (typ. values). 14 3-level half-bridge current monitor for current control. The current flowing through the HB MOSFET is sensed through a resistor. The resulting voltage is applied to this pin. First level threshold (1.
L6585DE Electrical data 2 Electrical data 2.1 Maximum ratings Table 2. Absolute maximum ratings Symbol Pin VBOOT 20 VOUT dVOUT /dt VCC Value Unit Floating supply voltage -1 to 618 V 18 Floating ground voltage -3 to VBOOT – 18 V 18 Floating ground max. slew rate 50 V/ns Self-limited V -0.3 to 5 V -0.3 to 2.7 V 17 1, 3, 4, 8, 10, 12 Parameter (1) IC supply voltage (ICC = 20 mA) Analog input and outputs 2, 5 VEOL 6 Maximum EOL voltage -0.
Electrical characteristics 3 L6585DE Electrical characteristics VCC = 15 V, TA = 25 °C, CL = 1 nF, COSC = 470 pF, RRUN = 47 kΩ, unless otherwise specified Table 4. Electrical characteristics Symbol Pin Parameter Test condition Min. Typ. Max. Unit 16 V Supply voltage Vcc VCC(on) VCC(OFF) VCC VCC VCC Operating range After turn-on Turn-on threshold (1) 13.6 14.3 15 V Turn-off threshold (1) 9.6 10.3 11 V 16.7 17.1 17.5 V 16 17.
L6585DE Table 4. Symbol Electrical characteristics Electrical characteristics (continued) Pin Parameter Test condition Min. Typ. Max. Unit CTR pin DIS CTR PFOV CTR Shutdown threshold Falling edge 0.75 V 120 mV 3.4 V 140 mV Lower threshold (falling) 1.7 V Hysteresis 120 mV Higher threshold (rising) 3.
Electrical characteristics Table 4. Symbol L6585DE Electrical characteristics (continued) Pin Parameter Test condition Min. Typ. Max. Unit Half bridge section – timing and oscillator ICH TCH Charge current VTCH = 2.2 V VCHP TCH Charge threshold (positive going-edge) (1) VCHN TCH Discharge threshold (negative going edge) (1) TCH Leakage current 1.5 V < VTCH < 4.
L6585DE Table 4. Symbol Electrical characteristics Electrical characteristics (continued) Pin Parameter Test condition Min. EOL EOL Half window amplitude Max. Unit +250 220 kΩ < REOLP < 270 kΩ VW Typ. -240 +160 22 kΩ < REOLP < 27 kΩ mV -150 REOLP > 620 kΩ 720 75 kΩ < REOLP < 91 kΩ 240 Sink/source capability 5.5 µA Half bridge section – Half-bridge current sense HBCSH HBCS Frequency increase VEOI < 1.9 V (ignition) 1.53 1.6 1.66 V HBCSL HBCS Threshold VEOI > 1.
Electrical characteristics Table 4. L6585DE Electrical characteristics (continued) Symbol Pin Parameter Test condition Min. Typ. Max. Unit TRISE HSD Rise time 120 ns TFALL HSD Fall time 80 ns HSD HSD-OUT pull-down 50 kΩ High-side floating gate-drive supply BOOT OUT Leakage current VBOOT = 600 V (2) Leakage current VOUT = 600 V Synchronous bootstrap diode on-resistance VLSD = HIGH (2) 5 µA 5 µA 250 Ω 1. Parameter in tracking 2.
L6585DE 4 Device description Device description The L6585DE embeds a high performance PFC controller, a ballast controller and all the relevant drivers necessary to build an electronic ballast. The PFC section achieves current mode control operating in transition mode, offering a highly linear multiplier including a THD optimizer that allows for an extremely low THD, even over a large range of input voltages and loading conditions.
Application information 5 Application information Figure 3. 5.1 L6585DE Typical application VCC section The L6585DE is supplied by applying voltage between the VCC pin and GND pin. An undervoltage lockout (UVLO) prevents the IC from operating with supply voltages too low to guarantee the correct behavior of the internal structures. An internal voltage clamp limits the voltage to around 17 V and can deliver up to 20 mA.
L6585DE Application information 5.2 PFC section 5.2.1 TM PFC operation The PFC stage contains all the features needed to implement a transition mode PFC controller. Figure 4. PFC section The control loop can be implemented thanks to the high performance error amplifier and the very precise internal voltage reference that fixes the non-inverting input of the E/A to 2.52 V ± 2 %. The control loop reacts in order to bring the inverting input to the same voltage.
Application information L6585DE The ZCD input can be connected directly to an auxiliary winding of the PFC choke in order to turn on the MOSFET when the choke current reaches zero. This pin has internal clamps and high current capability that makes it compliant with a very wide range of input voltage. At startup, when PFC choke is not yet energized, an internal starter gives ZCD pulses to the PFC gate driver with a repetition rate of approximately 15 kHz.
L6585DE 5.2.4 Application information Over-voltage protection Two different over-voltage protections can be detected: dynamic over-voltage, usually due to fast load transition and static over-voltage, due to an excessive input voltage. 5.2.5 ● Dynamic OVP The CTR pin is connected to high voltage rail through a voltage divider. If the voltage at this pin is above 3.4 V, the PFC gate driver is stopped until the voltage returns below the threshold.
Ballast section L6585DE 6 Ballast section 6.1 Half-bridge drivers and integrated bootstrap diode The half-bridge drivers are capable of 290 mA source and 480 mA sink current. This makes them able to effectively drive also big MOSFETs Cg up to 2.2 nF. The high-side MOSFET is driven by means of a bootstrapped structure reducing the number of external components. 6.2 Normal start-up description Referring to Figure 7, normal startup proceeds as follows: Figure 7. 18/33 Normal start-up procedure 1.
L6585DE Ballast section edge blanking is active during this time in order to avoid any detection of hard switching events, very common during this phase. 3. Ignition: At the end of the TCH cycle, the EOI pin is left free in high impedance mode. Therefore, the capacitor connected between EOI and ground is charged by RF through RPRE. The current sunk from the RF pin decreases exponentially, and the frequency along with it.
Ballast section L6585DE The oscillator characteristic curves represent the half bridge frequency versus the resistance R placed between RF pin and ground. During preheating R is equal to RRUN in parallel with RPRE whereas during Run mode R is equal to RRUN. Each curve is related to a value of the COSC capacitor and are depicted in Figure 10. The value of COSC is measured between pin 1 (OSC) and 15 (GND); for other capacitor values please refer to AN2870.
L6585DE 6.3 Ballast section Startup sequence with old or damaged lamps When an old lamp is connected to the ballast the strike voltage is higher than the nominal voltage and may also be higher than the safety threshold. In this case the lamp can ignite in a time longer than ignition time or may not ignite. In both cases, during ignition time, because of the frequency decrease, the voltage at the output of the ballast can easily reach dangerous values.
Ballast section 6.4 L6585DE Old lamp management during run mode During run mode, an old lamp can exhibit three different abnormal behaviors: ● Rectifying effect 6.5 ● Over-current ● Hard switching event Rectifying effect The rectifying effect is related to a differential increase of the ohmic resistance of the two cathodes. The lamp equivalent resistance is therefore higher when the lamp current flows in one direction than in the other.
L6585DE Ballast section Figure 12.
Ballast section L6585DE Figure 13.
L6585DE 6.6 Ballast section Over-current protection The appearance of over-current and hard switching events are related to a symmetrical increase of the ohmic resistance of the two cathodes. The overall effect results in an increased equivalent resistance of the lamp and a subsequent modification of the resonance curve of the resonance network (see Figure 14). Figure 14.
Ballast section L6585DE Figure 15. Example of capacitive mode operation due to ballast choke saturation OUT pin HBCS Good working Saturating slightly Capacitive mode Therefore, in ignition and run mode a comparator, connected to the HBCS pin, is active with a threshold respectively equal to 2.75 V and 1.6 V. It senses very high currents flowing in the ballast sense resistor and immediately latches the IC in low consumption mode. The width of the triggering spike is above 200 ns.
L6585DE Ballast section Figure 16.
Ballast section Table 6. L6585DE Table of faults Active during Fault Condition PH Ign IC behavior Required action Run Fault with immediate activation of latched operating mode Shutdown PFC feedback disconnection 9 9 9 9 9 9 VCTR < 0.75 V - Drivers stopped - IC low consumption (Vcc clamped) VCTR > 0.75 V (IC restarts with PH sequence) VCTR > 3.4 V and VINV < 1.
L6585DE 7 Package mechanical data Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK is an ST trademark.
Package mechanical data Table 7. L6585DE SO-20 mechanical data mm. inch Dim. Min. Typ. A a1 Max. Typ. 2.65 0.1 Max. 0.104 0.2 a2 0.004 0.008 2.45 0.096 b 0.35 0.49 0.014 0.019 b1 0.23 0.32 0.009 0.012 C 0.5 0.020 c1 45° (typ.) D 12.60 13.00 0.496 0.512 E 10.00 10.65 0.393 0.419 e 1.27 0.050 e3 11.43 0.450 F 7.40 7.60 0.291 0.300 L 0.50 1.27 0.020 0.050 M S Figure 17. Package dimensions 30/33 Min. 0.75 0.029 8° (max.
L6585DE 8 Ordering information Ordering information Table 8.
Revision history 9 L6585DE Revision history Table 9.
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