LS7083N LS7084N LSI/CSI UL ® LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 (631) 271-0400 FAX (631) 271-0405 A3800 April 2009 QUADRATURE CLOCK CONVERTER VDD (Pin 2) Supply Voltage positive terminal. VSS (Pin 3) Supply Voltage negative terminal. A (Pin 4) Quadrature Clock Input A. This input has a filter circuit to validate input logic level and eliminate encoder dither. B (Pin 5) Quadrature Clock Input B. This input has a filter circuit identical to input A. Mode (Pin 6) Mode is a 3-state input to select resolutions x1, x2 or x4. The selected resolution multiplies the input quadrature clock rate by 1, 2 and 4, respectively, in producing the outputs UPCK / DNCK and CLK (see Figure 2). The Mode input logic levels selects resolutions as follows: Logic 0 = x1 Float = x2 Logic 1 = x4 7083N/84N-042109-1 V DD (+V ) 2 V SS (-V ) 3 A 4 RBIAS 1 V DD (+V ) 2 V SS (-V ) 3 A 4 LS7084N INPUT/OUTPUT DESCRIPTION: RBIAS (Pin 1) Input for external component connection. A resistor connected between this input and VSS adjusts the output clock pulse width (Tow). For proper operation, the output clock pulse width must be less than or equal to the A, B pulse separation (TOW ≤ TPS). 1 LSI DESCRIPTION: The LS7083N and LS7084N are CMOS quadrature clock converters. Quadrature clocks derived from optical or magnetic encoders, when applied to the A and B inputs of the LS7083N or LS7084N, are converted to strings of Up Clocks and Down Clocks ( LS7083N) or to a Clock and an Up/Down direction control (LS7084N). These outputs can be interfaced directly with standard Up/Down counters for direction and position sensing of the encoder. RBIAS LS7083N Applications: • Interface incremental encoders to Up / Down Counters (See Figure 6A and Figure 6B) • Interface rotary encoders to Digital Potentiometers (See Figure 7) PIN ASSIGNMENT - TOP VIEW LSI FEATURES: • x1 and x4 mode selection • Up to 16MHz output clock frequency • Programmable output clock pulse width • On-chip filtering of inputs for optical or magnetic encoder applications. • TTL and CMOS compatible I/Os • +3V to +12V operation (VDD - VSS) • LS7083N, LS7084N (DIP); LS7083N-S, LS7084N-S (SOIC) - See Figure 1 8 UPCK 7 DNCK 6 MODE 5 B 8 CLK 7 UP/DN 6 MODE 5 B FIGURE 1 LS7083N - DNCK (Pin 7) In LS7083N, this is the DOWN Clock Output. This output consists of low-going pulses generated when A input lags the B input. LS7084N - UP/DN (Pin 7) In LS7084N, this is the count direction indication output. When A input leads the B input, the UP/DN output goes high indicating that the count direction is UP. When A input lags the B input, UP/DN output goes low, indicating that the count direction is DOWN. LS7083N - UPCK (Pin 8) In LS7083N, this is the UP Clock output. This output consists of low-going pulses generated when A input leads the B input. LS7084N - CLK (Pin 8) In LS7084N, this is the combined UP Clock and DOWN Clock output. The count direction at any instant is indicated by the UP/DN output (Pin 7). NOTE: For the LS7084N, the timing of CLK and UP/DN requires that the counter interfacing with LS7084N counts on the rising edge of the CLK pulses. ABSOLUTE MAXIMUM RATINGS: PARAMETER SYMBOL DC Supply Voltage VDD - VSS Voltage at any input VIN Operating temperature TA Storage temperature TSTG VALUE 16.0 VSS - 0.3 to VDD + 0.3 0 to +70 -55 to +150 UNITS V V °C °C DC ELECTRICAL CHARACTERISTICS: (All voltages referenced to VSS, TA = 0°C to 70°C.) PARAMETER Supply voltage Supply current SYMBOL VDD IDD MIN 3.0 - MAX 12.0 10.0 MODE Logic Low A, B Logic Low VIL VIL - MODE Logic High A, B Logic High VIH VIH VDD - 0.5 2.0 3.0 6.6 ALL OUTPUTS: Sink Current VOL = 0.4V IOL IOH Source Current VOH = VDD - 0.5V TRANSIENT CHARACTERISTICS: (TA = 0°C to 70°C) PARAMETER A, B inputs: Validation Delay SYMBOL UNITS V µA 0.5VDD 0.7 1.0 2.8 CONDITION VDD = 12V, All input frequencies = 0Hz RBIAS = 2MΩ V V V V VDD = 3V VDD = 5V VDD = 12V - V V V V VDD = 3V VDD = 5V VDD = 12V 1.3 1.9 2.9 - mA mA mA VDD = 3V VDD = 5V VDD = 12V 0.83 1.1 1.6 - mA mA mA VDD = 3V VDD = 5V VDD = 12V MIN MAX UNITS CONDITION TvD A, B inputs: Pulse Width - 250 170 71 ns ns ns VDD = 3V VDD = 5V VDD = 12V TPW TVD + TOW Infinite ns - A to B or B to A Phase Delay TPS TOW Infinite ns - A, B frequency fA, B - 1 2TPW Hz - Input to Output Delay TDS - 280 220 120 ns ns ns VDD = 3V VDD = 5V VDD = 12V Includes input validation delay Output Clock Pulse Width TOW 50 - ns See Fig. 4 & 5 7083N/84N-040609-2 FORWARD A REVERSE TPW TPS B TPS TDS UPCLK (7083N) 2 4 1 4 2 TOW DNCLK (7083N) CLK (7084N) 2 4 1 4 2 2 4 1 4 2 2 4 1 4 2 UP/DN (7084N) NOTE: Output clocks labeled 1, 2 and 4 have the following interpretations. 1. Generated in x1, x2 and x4 modes. 2. Generated in x2 and x4 modes only. 3. Generated in x4 mode only. FIGURE 2. LS7083N / LS7084N INPUT / OUTPUT TIMING RBIAS 1 CURRENT MIRROR A 4 FILTER B 5 FILTER DUAL ONE-SHOT DUAL ONE-SHOT x4 CLOCK CLOCK AND DIRECTION DECODE x2 CLOCK x1 CLOCK UP/DN MODE 6 V DD 2 +V VSS 3 -V 8 UPCK or CLK MUX 7 DNCK or UP/DN FIGURE 3. LS7083N/LS7084N BLOCK DIAGRAM 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. 7083N/84N-121206-3 2000 V DD = 3V 1500 V DD = 5V 30 V DD = 9V 25 V DD = 5V 1250 OUTPUT CLOCK PULSE WIDTH, Tow, ns V DD = 3V 35 OUTPUT CLOCK PULSE WIDTH, Tow, µs 1000 V DD = 12V 750 500 250 200 100 300 400 20 V DD = 9V 15 V DD = 12V 10 5 500 2 4 6 8 Figure 5. Tow vs RBIAS, M Figure 4. Tow vs RBIAS, k 10 12 SPDT (On - Off - On) +V +V +V V DD MODE ENCODER A CLOCK 4 B CLOCK 5 A B 1 UPCK LS7083N RBIAS RB DNCK +V 6 2 6 V DD 8 7 5 4 6 MODE CK-UP A CLOCK 40193 ENCODER CK-DN B CLOCK 4 A 5 B 1 V SS 16 VDD UPCK 8 15 7 10 LS7084N 8 CK UP/DN V SS Vss 3 RB V DD 4516 DNCK RBIAS V SS 3 2 8 FIGURE 6A. TYPICAL APPLICATION FOR LS7083N in x4 MODE FIGURE 6B*. TYPICAL APPLICATION FOR LS7084N in x2 MODE *See NOTE at bottom right of Page 1 +5V A1 ROTARY ENCODER 10k 10k 1M 1 2 VDD B 3 A GND RBIAS 10k 10k V SS 7083N/84N-042109-4 U/D MODE 4 A B 8 7 2 6 3 A1 B1 6 5 4 GND W1 5 LS7084N 0.01uF Part Number: RE11CT-V1Y12-EF2CS CLK DIGITAL POTENTIOMETER 1 CLK V DD 8 U/D CS AD5220 0.01uF FIGURE 7. Rotary Encoder Control of Digital Potentiometer 7 B1 W1