LS7231

LSI/CSI UL ® LS7231-7234 (631) 271-0400 FAX (631) 271-0405 December 2000 LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 A3800 TOUCH CONTROL LAMP DIMMER FEATURES: • Phase-lock loop synchronization allows use in Wall Switch applications. • Provides brightness control of incandescent lamps with touch plates or mechanical switches. • Controls the "duty cycle" from 23% to 88% (conduction angles for AC half-cycles between 41˚ and 158˚, respectively.) • Operates at 50Hz/60Hz line frequency. • Extension input for remote activation. • Input for slow dimming. • +12V to +18V DC Power Supply voltage. (VSS - VDD) • LS7231 to LS7234 (DIP) - See Figure 1 LS7231-S to LS7234-S (SOIC) DESCRIPTION: LS7231 through LS7234 are a series of monolithic, MOS integrated circuits designed for the control of brightness of incandescent lamps. The outputs of these ICs control the brightness of a lamp by controlling the firing angle of a triac connected in series with the lamp. All internal timings are synchronized with the line frequency by means of a built-in phase-lock loop circuit. The output occurs once every half-cycle of the line frequency. Within the halfcycle, the output can be positioned anywhere between 158˚conduction angle for maximum brightness and 41˚ conduction angle for minimum brightness in relation to the AC line frequency. The positioning of the output is controlled by applying a low level at the SENS input or a high level at the EXT input. These functions may be implemented with very few interface components, as shown in Figure 5. When implemented in this manner, touching of the Touch Plate causes the lamp brightness to change as follows: 1. If the Touch Plate is touched momentarily (42ms to 333ms), the lamp is: a) turned off if it was on, b) turned on if it was off. The brightness resulting is either full brightness or depending on the circuit type, a previous brightness stored in the IC memory. 2. If the Touch Plate is touched for a prolonged time (more than 342ms) the light intensity changes slowly. As long as the touch is maintained, the change continues; the direction of change reverses whenever the maximum or minimum brightness is reached. PIN ASSIGNMENT - TOP VIEW LSI V SS(+V) DOZE 1 2 8 TRIG V DD (-V) 7 LS7231-34 CAP SYNC 3 4 6 5 EXT SENS FIGURE 1 The IC also provides an input for slow dimming. By applying a slow clock to this input, the lamp can be dimmed slowly until total turn off occurs. This feature can be useful at bedtime in a child’s room. INPUT/OUTPUT DESCRIPTION: VSS (Pin 1) Supply voltage positive terminal. DOZE (Pin 2) A clock applied to this input causes the brightness to decrease in equal increments with each negative transition of the clock. Eventually, when the lamp turns off, this input has no further effect. The lamp can be turned on again by activating either the SENS input or the EXT input. For the transition from maximum brightness to off, a total of 83 clock pulses are needed at the DOZE input. When either the SENS or the EXT input is active, the DOZE input is disabled. (See Figure 7) CAP (Pin 3) The CAP input is for the PLL filter capacitor. A 0.047µF capacitor should be connected to this input. 7231-4-120100-1 The functional differences of different versions of the light dimmer ICs are explained in Table 1 and the TRIG output conduction angle diagrams in Figure 2. PART NUMBER TABLE 1 TOUCH TYPE SHORT (TS1 Duration) PRE-TOUCH Ø Off Max Intermediate POST-TOUCH Ø Max Off Off LONG (TS2 Duration) PRE-TOUCH Ø Off Max Intermediate POST-TOUCH Ø Starts varying at Min Starts varying at Max Starts varying at Pre-Touch brightness Starts varying at Memory (Note 2) Starts varying at Max Starts varying at Pre-Touch brightness Starts varying at Min Starts varying at Max Starts varying at Pre-Touch brightness Starts varying at Memory (Note 2) Starts varying at Max Starts varying at Pre-Touch brightness DIMMING DIRECTION REVERSAL (Note 3) LS7231 N/A N/A NO LS7232 Off Max Intermediate Memory (Note 1) Off Off Off Max Intermediate YES N/A YES LS7233 Off Max Intermediate Max Off Off Off Max Intermediate N/A N/A YES LS7234 Off Max Intermediate Memory (Note 1) Off Off Off Max Intermediate NO N/A NO NOTE 1: "Memory" refers to the conduction angle, Ø which existed prior to the current off-state. First time after power-up, the Memory value defaults to maximum conduction angle. NOTE 2: First time after power-up, LONG touch causes intensity to vary starting at minimum conduction angle. NOTE 3: NO = Dimming direction does not reverse from prior dimming direction. YES = Dimming direction does reverse from prior dimming direction. N/A = Does not apply SYNC (Pin 4) The AC Line Frequency is applied to this input through an external RC circuit (See Figure 5). The Phase-Lock Loop in the IC synchronizes all internal timings to the AC signal at the SYNC input. SENS (Pin 5) A low level activates this input (See Table 1) which controls the turn-on, turn-off and conduction angle Ø (SeeFigure 3) of the TRIG signal with respect to the SYNC input. EXT (Pin 6) The EXT input is functionally identical to the SENS input except that a high level activates this input. It is recommended that the EXT input be used instead of the SENS input when long extension wires are employed between the IC and the Sensing Circuitry (See Figure 5 and Figure 6) because the EXT input is less susceptible to “Noise”. VDD (Pin 4) Supply voltage negative terminal. 7231-34-033195-2 TRIG (Pin 8) The TRIG output is a low level pulse occurring once every half-cycle of the SYNC input. The conduction angle, Ø, of the output in relation to the SYNC signal controls the lamp brightness. In continuous dimming operation (i.e. when the SENS input is continuously held low) the TRIG conduction angle, Ø, sweeps up and down between 41˚ and 158˚ continuously. The time vs Ø curve is not linear (See Figure 2). Between two maxima on this curve, there are 4 discontinuous points labeled A1, B1, B2, A2. The discontinuities are as follows: 1. From maximum to A1. In this region, Ø is changed by equal increments (∆ø) for every 2 SYNC clocks. 2. From A1 to B1. In this region, the increments (∆ø) take place for every 4 SYNC clocks. 3. From B1 to B2. In this region Ø is held at a constant level (∆ø = 0). 4. From B2 to A2. Same as 2. 5. From A2 to Max. Same as 1. The slower rate of change in ø over A1B1B2A2 region is to accommodate for eye adjustment at lower light intensity. ABSOLUTE MAXIMUM RATINGS: PARAMETER SYMBOL DC Supply Voltage VSS Any Input Voltage VIN Operating Temperature TA Storage Temperature TSTG DC ELECTRICAL CHARACTERISTICS: (TA = 25˚C, all voltages referenced to VDD) PARAMETER Supply Voltage Supply Current Input Voltages: DOZE LO DOZE HI SYNC LO SYNC HI SENS LO SENS HI EXT LO EXT HI Input Current: SYNC, SENS, EXT HI SYMBOL VSS ISS VALUE +20 VSS -20 to VSS + 0.5 0 to +80 -65 to +150 UNIT V V ˚C ˚C MIN +12 – TYP – 1.0 MAX +18 1.4 UNIT V mA CONDITION VSS = +15V, output off With Series 1.5MΩ Resistor to 115VAC Line VSS = +15V VSS = +15V VOL = VSS-4V VIZL VIZH VIRL VIRH VIOL VIOH VIVL VIVH 0 VSS-2 0 VSS-5.5 0 VSS-2 0 VSS-2 – – – – – – – – VSS-6 VSS VSS-9.5 VSS VSS-8 VSS VSS-8 VSS V V V V V V V V IIH – – 110 µA SYNC, SENS, EXT LO DOZE HI DOZE LO TRIG HI Voltage TRIG LO Voltage TRIG Sink Current IIL IIH IIL VOH VOL IOS – – – – – 25 – – – VSS VSS-8 – 100 100 100 – – – nA nA nA V V mA TIMING CHARACTERISTICS (See Figures 2 and 3): All timings are based on fs = 60Hz, unless otherwise specified. 50Hz timings are 1.2 times 60Hz timings. PARAMETER SYMBOL MIN TYP MAX UNIT SYNC Frequency fs 40 70 Hz SHORT TOUCH TS1 42 333 ms (ON/OFF Operation) LONG TOUCH TS2 342 infinite ms (Dimming Operation) DOZE Frequency 500 Hz TRIG Pulse Width TW 33 µs TRIG Conduction-Angle Ø 41 158 degrees (Note 1) Ø Period (Max to Max in 7.64 seconds continuous dimming) A1B1 = B2A2 duration 934 ms B1B2 Min. intensity dwell 500 ms NOTE 1. In the circuit schematic shown in Figure 5, the SYNC input signal is delayed in phase with respect to the AC Line by about 7°. This delay reduces the conduction angle, Ø with respect to the AC Line by 7° from the values shown above. 7231-34-041195-3 TS1 SENS TS2 LS7231 SHORT 341ms A0 LONG SHORT LONG SHORT LONG 150° 100° 50° OFF LS7232 150° 100° 50° OFF LS7233 A0 150° 100° 50° OFF SBA LS7234 150° 100° 50° OFF SAA A0 A1 A2 A0 MEMORY SBA B1 B2 SAA SAA A1 SBA B1 B1 B2 MEMORY SBA A2 B2 SAA A1 SBA B1 B2 A2 SAA REVERSE SBA B2 SAA SAA B1 B2 A0 A1 SBA A2 A0 MEMORY MEMORY SAA SAA SAA B2 SBA A2 SLOPE = SAA A1 SLOPE = SBA B1 B2 SAA A2 SAA B2 SBA SBA = 1.4° per four SYNC CYCLES, 15 steps total for A1 to B 1 or B2 to A 2 SAA = 1.4° per two SYNC CYCLES, 68 steps total for A 0 to A1 or A2 to A0 FIGURE 2. TRIG OUTPUT CONDUCTION ANGLE, Ø, VS SENS INPUT 7231-4-032795-4 SYNC ø TRIG TW TW FIGURE 3. TRIG OUTPUT CONDUCTION ANGLE, Ø SYNC CAP DOZE 4 3 2 BUF PHASE LOCK LOOP Ø MEMORY BUF DIGITAL COMPARATOR OUTPUT DRIVER 8 TRIG EXT 6 BUF CONTROL LOGIC Ø POINTER SENS 5 BUF V SS V DD 1 7 (+V) (-V) F IGURE 4 LS7231-4 BLOCK DIAGRAM APPLICATION EXAMPLE: A typical implementation of a lamp dimmer circuit is shown in Fig. 5. Here the brightness of the lamp is set by touching the Touch Plate . The functions of different components are as follows: • The 15V 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 C7 act as a filter circuit for the electronic extension. If extensions are not used, the EXT input (Pin 6) should be tied to VDD (Pin 7). • R4, R5, R6 set up the sensitivity of the SENS input. C6 provides noise filtering. • 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 RF filter circuits. In the case of momentary power failure, the circuit state remains unchanged for a period of up to 1 sec. For longer power interruptions, the output is shut off. 7231-4 040695-5 FIGURE 5. A Typical Lamp Dimmer P R8 + Z SEE NOTE 2 G MT1 MT2 P C7 R3 R7 EXTN T - C5 SEE NOTE 5 ELECTRONIC EXTENSION (FIG. 6) R6 R5 115VAC OR 220VAC L C1 D1 8 C2 TRIG 7 6 5 TOUCH PLATE V DD EXT S E N S LS7231-4 V DD SENS DOZE CIRCUIT (FIG. 7) R1 R2 A V SS D O Z E CAP SYNC 1 2 3 4 C3 C4 C6 R4 SEE NOTE 3 LOAD B SEE NOTE 4 DZ V SS N N O T E S 1) All circuits connected by broken lines are optional. 2) C7 is used only with electronic extension and R7 is used only with mechanical switch. 3) Connection between Pin 1 & Pin 2 should be broken when DOZE circuit is used. 4) Use Connection A when Neutral is not available. Use Connection B when Neutral is available. 5) Connection between Pin 6 & Pin 7 should be broken when EXT is used. C1 = 0.15µF,200V (1) C2 = 0.33µF,200V C3 = 0.047µF,25V C4 = 470pF,25V C5 = 47µF,25V C6 = 680pF,25V C7 = 0.1µF,25V (2) R1 = 270Ω,1W R2 = 1.5MΩ,1/4W R3 = 1.5MΩ,1/4W 115V R4 = 1MΩ to 5MΩ,1/4W (Select for sensitivity) R5, R6 = 2.7MΩ,1/4W R7 = 150KΩ,1/4W R8 = 100Ω,1/4W D1 = IN4148 Z = 15V,1W (Zener) T = Q4006L4 Triac (Typical) L = 100µH (RFI Filter) 220V C1 = 0.15µF, 400V (3) C2 = 0.22µF, 400V C3 = 0.047µF, 25V C4 = 470pF, 25V C5 = 47µF, 25V C6 = 680pF,25V C7 = 0.1µF, 25V (4) R1 = 1KΩ, 2W R2 = 1.5MΩ,1/4W R3 = 1.5MΩ,1/4W R4 = 1MΩ to 5MΩ,1/4W (Select for sensitivity) R5, R6 = 4.7MΩ,1/4W R7 = 150KΩ,1/4W R8 = 100Ω,1/4W D1 = 1N4148 Z = 15V,1W (Zener) T = Q5004L4 Triac (Typical) L = 200µH (RFI Filter) (1) For Connection A. Use 0.22µF for Connection B. (2) For Connection A. Use 1/4W for Connection B. 7231-4-041597-6 (3) For Connection A. Use 0.1µF for Connection B. (4) For Connection A. Use 1/4W for Connection B. TOUCH PLATE *R 2K Ω ,1/4W EXTN MPS8599 *R = 2M Ω ,1/4W for 115VAC *R = 3.6M Ω ,1/4W for 220VAC 200K Ω ,1/4W IN914 *R P FIGURE 6. ELECTRONIC EXTENSION EXTENSIONS: All switching and dimming functions can also be implemented by utilizing the EXT input. This can be done by either a mechanical switch or the electronic switch in conjunction with a Touch Plate as shown in Figure 6. When the plate is touched, a logic high level is generated at the EXT input of the IC for both half- cycles of the line frequency. (See Figure 5) VSS 3.3M ,1/4W U1-1 3.3M ,1/4W DZ U1-3 + 10µF SENS U1-2 DOZE SWITCH DZ VDD FIGURE 7. DOZE CIRCUIT U1 = CD4093 - DOZE CIRCUIT: The DOZE circuit shown in Figure 7 generates a slow clock (0.04Hz) at the DZ terminal. If the Touch Plate (Figure 5) is not touched, the SENS terminal of the DOZE circuit of Figure 7 sits at a logic high level. A momentary pressing of the DOZE switch sets the SR flip-flop, enabling the oscillator. Every negative transition of the clock (DZ terminal) causes the light intensity to be reduced by equal increments, until eventually the light is shut off. The oscillator has no further effect on the dimmer circuit. When the light is turned on again by touching theTouch Plate, the SR flip-flop is reset and the DZ clock is turned off. When the DOZE circuit is used, the connection between DOZE input (Pin 2) and VSS (Pin 1) as shown in Figure 5, should be removed. . 7231-4-041195-7 FIGURE 8. A SWITCH-OPERATED LAMP DIMMER AC ON-OFF SWITCH G MT1 R3 + T1 MT2 C5 Z1 D1 L - PUSHBUTTON SWITCH 115VAC OR (SEE NOTE) 220VAC C1 C2 8 7 6 5 TRIG V DD EXT S E N S R1 R2 LS7231-4 V SS D O Z E CAP SYNC 1 2 3 4 C3 OUT TO LAMP C4 R4 NOTE: Operation is independent of Line Plug Polarity 115V C1 = 0.15µF, 200V C2 = 0.22µF, 200V C3 = 0.047µF, 25V C4 = 470pF, 25V C5 = 47µF, 25V R1 = 270Ω, 1/4W R2 = 1.5MΩ, 1/4W R3 = 100Ω, 1/4W R4 = 1MΩ, 1/4W D1 = IN4148 Z1 = 15V, 1W (Zener) T1 = Q4008L4 (Typical) L = 100µH (RFI Filter) 220V C1 = 0.15µF, 400V C2 = 0.1µF, 400V C3 = 0.047µF, 25V C4 = 470pF, 25V C5 = 47µF, 25V R1 = 1KΩ, 1/4W R2 = 1.5MΩ, 1/4W R3 = 100Ω, 1/4W R4 = 1MΩ, 1/4W D1 = IN4148 Z1 = 15V, 1W (Zener) T1 = Q5004L4 (Typical) L = 200µH (RFI Filter) APPLICATIONS: 1. Foot-Switch Dimmer for large floor lamps. 2. Hand-Switch Dimmer for end-table lamps. 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. 7231-4-032995-8