LSI/CSI UL ® LS7631/7632 LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 (631) 271-0400 FAX (631) 271-0405 A3800 TOUCH CONTROL HALOGEN LAMP DIMMER BACKGROUND AND GENERAL DESCRIPTION: A typical electronic dimmer may not operate properly with the inductive load encountered when driving a transformer-coupled low-voltage halogen lamp. The inductive load can cause a phenomenon called half-waving, wherein the triac fires in alternate half-cycles only, which may lead to the thermal destruction of the load transformer. The problems encountered in driving an inductive load are addressed by the LS7631/LS7632 CMOS ICs as follows: V DD (+V) 1 MODE 2 CAP 3 SYNC 4 LS7631 LS7632 APPLICATIONS: Electronic dimmers for wall switch control of ceiling mounted lighting, foot switch control of large floor lamps and hand switch control of table lamps. PIN ASSIGNMENT - TOP VIEW LSI FEATURES: • Touch or pushbutton control of incandescent lamps and transformer-coupled halogen lamps • Transformer can be Magnetic or Electronic • Direct replacement for P/N SLB 0587 • Automatic safety shutdown • PLL synchronization allows use as a Wall Switch • Three operating modes • Extension input for remote activation • 50Hz/60Hz AC line frequency • +5V Power Supply (VDD - VSS) • LS7631, LS7632 (DIP); LS7631-S, LS7632-S (SOIC) November 2002 8 TRIG 7 V SS (-V) 6 EXT 5 SENS FIGURE 1 INPUT/OUTPUT DESCRIPTION: VDD (Pin 1) Supply voltage positive terminal. Vss (Pin 7) Supply voltage negative terminal. MODE (Pin 2) - See Table 1 Both LS7631 and LS7632 can operate in 3 different modes. The 3-state MODE input selects the operating modes: Vss = Mode 0; Float = Mode 1; VDD = Mode 2 CAP (Pin 3) - PLL filter capacitor input. See Figure 6. 1. Compensation for delayed triac cut-off. When a trigger pulse is due to occur at a conduction angle which coincides with the on-state of the triac, the trigger pulse is delayed until the triac has turned off. This eliminates the underlying cause of half-waving. . 2. Compensation for delayed triac turn-on. At the set conduction angle, a triac trigger pulse of 130.2µs (60 Hz) is issued by the IC. If the triac fails to fire, a second trigger pulse of 260.4µs width is issued 1ms later as a second attempt to fire the triac during the same half-cycle. SYNC (Pin 4) - See Figure 6 The AC line frequency is applied to this input. All internal timings are synchronized to the AC phase through a PLL circuit. The Load On/Off status information is also derived from this input. 3. Safety-shutdown. If the frequency of occurrences of the delayed cut-off and delayed turn-on exceeds a preset threshold, a shutdown is initiated by turning off the triac trigger pulses. The safetyshutdown threshold value is accumulated in a 4-bit Up/Down counter. The count increments for every occurrence of delayed cut-off or delayed turn-on and decrements once every 8 SYNC pulses (AC line cycles). The counter will not decrement below zero. If the count reaches 15, the safetyshut-down is effected. EXT (Pin 6) Same functionality as the SENS input, except that a Logic 1 is the active level at this input. EXT input is intended to be operated from a remote site with long cable connection, when noise can be expected. The sampling method used at this input makes it less sensitive to noise. 7631/7632-112002-1 SENS (Pin 5) - See Table 1 A Logic 0 applied to this input alters the TRIG output either by turning it on, turning it off or by changing its conduction angle. Specifically which action takes place is dependent on the type of activation of the SENS input, namely SHORT or LONG touch and the prior state of TRIG output. TRIG (Pin 8) The TRIG output is a low level pulse occurring once every halfcycle of the AC and is intended to drive the gate of a triac in series with the load. The conduction angle, ø, of the TRIG pulse can be varied by means of LONG and SHORT touches at either the SENS or the EXT input. The functional differences between LS7631 and LS7632 are: LS7631 - When a LONG touch is applied, the dimming direction automatically reverses whenever maximum or minimum conduction angles are reached. LS7632 - When a LONG touch is applied, the dimming stops whenever maximum or minimum conduction angles are reached. In order to change dimming levels from maximum or minimum, LONG touch must be removed and reapplied.The purpose of this feature is to allow the user to positively locate maximum and minimum conduction angles. LS7632 NOTE: If the User applies a LONG Touch when the TRIG Conduction Angle is within a “few” degrees of Maximum or Minimum, the TRIG Conduction Angle can move to Maximum or Minimum and stop without the User being able to observe a change in brightness. Therefore, the User should be instructed that if no change in brightness is observed in response to a LONG Touch, the LONG Touch should be removed and reapplied in order to produce a change in brightness. TABLE 1 MODE SHORT TOUCH PRE-TOUCH Ø 0 Note 1: Note 2: Note 3: Note 4: Note 5: POST-TOUCH Ø PRE-TOUCH Ø POST-TOUCH Ø DIMMING REVERSAL (Note 5) OFF ON MAX(Note 1) OFF OFF/MIN MAX INTERMEDIATE Varies up from MIN Varies down from MAX Varies from INTERMEDIATE N/A N/A NO OFF ON MEMORY (Notes 2, 3) OFF OFF MIN MAX INTERMEDIATE Varies from memory (Notes 2, 3,4) Varies up from MIN Varies down from MAX Varies from INTERMEDIATE YES N/A N/A YES OFF ON MAX (Note 1) OFF OFF/MIN MAX INTERMEDIATE Varies up from MIN Varies down from MAX Varies from INTERMEDIATE N/A N/A YES 1 2 LONG TOUCH A soft turn-on is produced by slewing up the conduction angle, ø, from minimum at the rate of 1.4˚/4.17ms (60Hz). There are a total of 84 discrete values of ø. A soft turn-on is produced by slewing up ø, from minimum to memory. Upon power-up the memory value is defaulted to maximum conduction angle. “Memory” refers to the conduction angle, ø, which existed prior to the current off-state. A soft turn-on is produced by slewing up ø from minimum to memory upon which the dimming is started. NO = Dimming direction does not reverse from prior dimming direction. YES = Dimming direction does reverse from prior dimming direction. N/A = Does not apply. ABSOLUTE MAXIMUM RATINGS: PARAMETER SYMBOL VALUE UNIT DC supply voltage Any input voltage Operating temperature Storage temperature VDD - Vss VIN TA TSTG +7 Vss - 0.3 to VDD + 0.3 0 to +90 -65 to +150 V V °C °C DC ELECTRICAL CHARACTERISTICS: (TA = +25˚C, all voltages referenced to Vss. VDD = +5V unless otherwise noted.) PARAMETER SYMBOL MIN TYP MAX UNIT Supply voltage Supply current VDD IDD 4.5 - 5.0 300 5.5 400 V µA SYNC Lo VISL - - 2.1 V SYNC Hi VISH 2.9 - - V - EXT, SENS Lo VIEL - - 1.5 V - EXT, SENS Hi TRIG Lo TRIG Hi VIEH VOL VOH 3.5 - 0.2 5.0 - V V V - TRIG Sink Current ITSNK 35 - - 7631/7632-111902-2 mA CONDITION Output unloaded VDD = 5.5V - VOTRIG = 2.5V TIMING CHARACTERISTICS (See Figures 2, 3 and 4): PARAMETER SYMBOL MIN TYP MAX fs TSI TSI TS2 TS2 Tw Tw ø ∆ø 40 42 50 342 410 41 - 130.2 156.2 1.4 70 333 400 infinite infinite 158 - Hz ms ms ms ms µs µs deg deg - deg/4.17ms deg/5ms deg/33.3ms deg/40ms deg/66.7ms deg/80ms ms ms SYNC Frequency SHORT Touch LONG Touch TRIG pulse width Conduction Angle ø incremental steps (Note 1) Soft-on slew rate SS SS SAA SAA SBA SBA TBD TBD A0 to A1/A2 to A0 slew rate (Note 2) A1 to B1/B2 to A2 slew rate (Note 3) B1 to B2 delay (Note 4) Note 1: Note 2: Note 3: Note 4: - 1.4 1.4 1.4 1.4 1.4 1.4 500 600 UNIT CONDITION 60Hz 50Hz 60Hz 50Hz 60Hz 50Hz 60Hz 50Hz 60Hz 50Hz 60Hz 50Hz 60Hz 50Hz Total number of steps = 83. Number of steps from A0 to A1, or A2 to A0 = 68. Number of steps from A1 to B1 or B2 to A2 = 15. ø is at minimum between B1 and B2. TBD is applicable for LS7631 only. For LS7632 when minimum ø is reached, dimming direction reverses only if the LONG Touch is terminated and reapplied. FIGURE 2. TRIG OUTPUT CONDUCTION ANGLE, Ø REPLACEMENT FOR P/N SLB 0587 LS7631 and LS7632 can be used in place of the SLB 0587 without modifying the application circuit recommended by the manufacturer of that IC. SYNC ø The information included herein is believed to be accurate and reliable. However, LSI Computer Systems, Inc. assumes no responsibilities for inaccuracies, nor for any infringements of patent rights of others which may result from its use. TRIG TW FIGURE 3. LS7631 TRIG, Ø vs TOUCH (SENS OR EXT) TS1 TS2 SENS SHORT SHORT LONG SHORT LONG SHORT A0 150º Ø MODE Ø 50º OFF SLOPE = S BA 342ms 100º A2 SLOPES = S AA A1 SLOPE = Ss A2 B1 B2 MEMORY A0 A0 150º Ø MODE 1 100º 50º A1 OFF B1 B2 REVERSE A2 A0 150º Ø MODE 2 100º 50º OFF 7631/7632-112102-3 A2 A1 A2 B1 B2 REVERSE LONG FIGURE 4. LS7632 TRIG, Ø vs TOUCH (SENS OR EXT) TS1 TS2 SENS Ø MODE Ø LONG SHORT SHORT LONG LONG LONG 342ms 150º 100º LONG SHORT SLOPE = S BA A0 A0 50º SHORT A2 OFF A1 SLOPE = S AA B1 A2 B2 A2 SLOPE = S S MEMORY MEMORY 150º 100º Ø MODE 1 REVERSE 50º A1 B1 B2 OFF A2 A2 A1 B1 B2 A0 A0 REVERSE 150º 100º Ø MODE 2 A0 A0 50º A2 A2 OFF FIGURE 6. A Typical Halogen Lamp Dimmer Wall Switch P SEE NOTE 2 P MT1 Z R7 EXTN R3 + C5 T MT2 C6 R8 G ELECTRONIC EXTENSION (FIG. 7) - SEE NOTE 3 D1 L 115VAC OR 220VAC R6 C1 8 C2 7 6 5 TOUCH PLATE TRIG V SS EXT S E N S LS7631/LS7632 R1 V DD MODE R2 1 2 CAP SYNC 3 4 C3 SEE NOTE 4 R5 LAMP C4 R4 NOTES 1. All circuits connected by broken lines are optional. 2. C6 is used only with electronic extension and R7 is used only with a pushbutton. 3. Connection between Pin 6 & Pin 7 should be broken when EXT is used. 4. As a precaution, transformer should have thermal protection. N C1 = 0.15µF, 200V = 0.15µF, 400V * C1 C2 = 0.15µF, 200V * C2 = 0.082µF, 400V C3 = 0.02µF, 10V C4 = 0.002µF, 10V * = component change for 220VAC FIGURE 7. C5 = 100µF, 10V C6 = 0.1µF, 10V R1 = 270Ω, 1/2W * R1 = 1kΩ, 1W R2 = 680Ω, 1/4W = 1.5MΩ, 1/4W * R2 R3 = 1.5MΩ, 1/4W Z = 5.6V, 1W (Zener) T = Q4004L4 Typical Triac (1) * T = Q5003L4 Typical Triac (1) L = 100µH (RFI Filter) 200µH (RFI Filter) * L(1)= For loads greater than 6A, use an alternistor . ELECTRONIC EXTENSION MPS8599 EXT R4 = 1MΩ to 5MΩ, 1/4W (Select for Sensitivity) R5, R6 = 2.7MΩ, 1/4W * R5, R6 = 4.7MΩ, 1/4W R7 = 150kΩ, 1/4W R8 = 62Ω, 1/4W D1 = 1N4148 IN914 *R *R 10kΩ APPLICATION EXAMPLE: A typical implementation of the light dimmer circuit is shown in Fig. 6. Here the brightness of the lamp is set by touching the touch plate. The function of different components are as follows: TOUCH PLATE 200k Ω *R = 2M Ω for 115VAC *R = 3.6M Ω for 220VAC All Resistors 1/4W P EXTENSIONS: All switching and dimming functions can be implemented by utilizing the EXT input. Use a pushbutton or the electronic switch in conjunction with a Touch Plate as shown in Figure 7. When the plate is touched, a logic high level is generated at the EXT input of the IC for both halfcycles of the line frequency. (See Figure 6) 7631/32-112102-4 • The 5V DC supply for the chip is provided by Z, D1, R1, C2 and C5. • R2 and C4 generate the filtered signal for the SYNC input for synchronizing the internal PLL with the line frequency. • R3 and C6 act as a filter circuit for the electronic extension. If extensions are not used, the EXT input (Pin 6) should be tied to Vss (Pin 7). • R4, R5 and R6 set up the sensitivity of the SENS input. • C3 is the filter capacitor for the internal PLL. • R8 provides current limiting and isolation between the chip output and the triac gate. • C1 and L are RFI filter circuits.