LSI/CSI UL ® LS7183/LS7184 LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 (631) 271-0400 FAX (631) 271-0405 A3800 August 2001 QUADRATURE CLOCK CONVERTER 1 V DD(+V) 2 VSS(-V) 3 A 4 1 V DD(+V) 2 VSS(-V) 3 A 4 LS7184 RBIAS LS7183 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). RBIAS LSI DESCRIPTION: The LS7183 and LS7184 are monolithic CMOS silicon gate quadrature clock converters. Quadrature clocks derived from optical or magnetic encoders, when applied to the A and B inputs of the LS7183/LS7184, are converted to strings of Up Clocks and Down Clocks (LS7183) or to a Clock and an Up/ Down direction control (LS7184). These outputs can be interfaced directly with standard Up/Down counters for direction and position sensing of the encoder. PIN ASSIGNMENT - TOP VIEW LSI FEATURES: • x1, x2 and x4 resolution • Programmable output pulse width (200ns to 140µs) • Excellent regulation of output pulse width • TTL and low voltage CMOS compatible I/Os • +3V to +5.5V operation (VDD-VSS) • LS7183, LS7184 (DIP) LS7183-S, LS7184-S (SOIC) - See Figure 1 8 UPCK 7 DNCK 6 MODE 5 B 8 CLK 7 UP/DN 6 MODE 5 B FIGURE 1 VDD (Pin 2) Supply Voltage positive terminal. VSS (Pin 3) Supply Voltage negative terminal. A, B (Pin 4, Pin 5) Quadrature Clock inputs A and B. Directional output pulses are generated from the A and B clocks according to Fig. 2. A and B inputs have built-in immunity for noise signals less than 50ns duration (Validation delay, TVD). The A and B inputs are inhibited during the occurrence of a directional output clock (UPCK or DNCK), so that spurious clocks resulting from encoder dither are rejected. MODE (Pin 6) MODE is a 3-state input to select resolution x1, x2 or x4. The input quadrature clock rate is multiplied by factors of 1, 2 and 4 in x1, x2 and x4 mode respectively in producing the output UP/DN clocks (See Fig. 2). x1, x2 and x4 modes selected by the MODE input logic levels are as follows: Mode = 0 : x1 selected Mode = 1 : x2 selected Mode = Float : x4 selected 7183/84-071201-1 LS7183 - DNCK (Pin 7) In LS7183, this is the DOWN Clock Output. This output consists of low-going pulses generated when A input lags the B input. LS7184LV - UP/DN (Pin 7) In LS7184, 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. LS7183 - UPCK (Pin 8) In LS7083LV, this is the UP Clock output. This output consists of low-going pulses generated when A input leads the B input. LS7184 - CLK (Pin 8) In LS7184, 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 LS7184, the timing of CLK and UP/DN requires that the counter interfacing with LS7184 counts on the rising edge of the CLK pulses. ABSOLUTE MAXIMUM RATINGS: PARAMETER DC Supply Voltage Voltage at any input Operating temperature Storage temperature SYMBOL VDD - VSS VIN TA TSTG VALUE 7.0 VSS - .3 to VDD + .3 -20 to +85 -55 to +150 UNITS V V °C °C DC ELECTRICAL CHARACTERISTICS: (Unless otherwise specified VDD = 3V to 5V and TA = -20°C to 85°C) PARAMETER Supply Voltage Supply current SYMBOL VDD IDD IDD MIN 3.0 - TYPE 30 110 MAX 5.5 45 150 UNITS V µA µA CONDITON VDD = 3V VDD = 5V Vml Vmh Vmf VDD -0.6 (VDD/2) - 0.5 VDD/2 0.6 (VDD/2) + 0.5 V V V - Logic 0 input current Iml Iml - 3.0 12.0 5.0 16.0 µA µA VDD = 3V VDD = 5V Logic 1 input current Imh Imh - -3.0 -12.0 -5.0 -16.0 µA µA VDD = 3V VDD = 5V VABl VABh IABlk 0.7VDD - 0 0.3VDD 10 V V nA - RB 5k - 10M ohm - Sink current Iol Iol -1.2 -2.5 -1.8 -3.5 - mA mA Vo = 0.5V, VDD = 3V Vo = 0.5V, VDD = 5V Source current Ioh Ioh 1.2 2.5 1.8 3.5 - mA mA Vo = 2.5V, VDD = 3V Vo = 4.5V, VDD = 5V SYMBOL TOW MIN 190 TYPE - MAX - UNITS ns TVD TVD - 25 50 50 100 ns ns VDD = 5V VDD = 3V Phase Delay TPS TVD +TOW - Infinite s - Pulse Width TPW 2TPS - Infinite s - Frequency fA,B - - 1/(2TPW) Hz - Inupt to Output Delay TDS TDS - 200 110 270 150 ns ns VDD = 3V VDD = 5V MODE input: Logic 0 Logic 1 Logic float A,B inputs: Logic 0 Logic 1 Input current RBIAS input: External resistor All outputs: TRANSIENT CHARACTERISTICS (TA = -20°C to 85°C) PARAMETER Output Clock Pulse Width A,B inputs: Validation Delay 7183/84-070601-2 CONDITON See Fig. 2 FORWARD A REVERSE TPW TPS TPS 4 1 B TDS UPCLK (7183LV) 2 4 2 TOW DNCLK (7183LV) CLK (7184LV) 2 4 1 4 2 2 4 1 4 2 2 4 1 4 2 UP/DN (7184LV) NOTE: Output clocks labelled 1, 2 and 4 have the following interpretations. 1: Generated in x1, x2 and x4 modes 2: Generated in x2 and x4 modes only 4: Generated in x4 mode only FIGURE 2. LS7183, LS7184 INPUT/OUTPUT TIMING A 4 DIRECTION FILTER INHIBIT LOGIC B MUX AND BUFFER 8 UPCK or CLK FILTER 5 7 RBIAS 1 CURRENT MIRROR DNCK or UP/DN PULSE V DD 1M MODE MODE DECODE 6 1M V DD 2 V SS 3 FIGURE 3. LS7183, LS7184 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. 7183/84-071201-3 RBIAS vs Tow 10000 9000 8000 7000 Tow,ns 6000 5000 4000 3000 2000 1000 0 5 10 20 51 100 220 430 750 R, kohm Figure 4. Bias resistance vs pulse width. R in kΩ. RBIAS vs Tow 160 140 Tow, us 120 100 80 60 40 20 0 1 2 3 5.1 6.8 8.2 10 R, Mohm Figure 5. Bias resistance vs pulse width. R in MΩ. SPDT (On - Off - On) +V +V +V 6 16 2 V DD V DD MODE 8 A CLOCK E N C O D E R B CLOCK 4 5 A CLOCK 7 DNCK 1 RB V DD MODE CK-UP LS7183 B 16 2 6 5 UPCK A +V 10K 4 B CLOCK 5 Vss 1 Vss 3 4516 7 B RB 10 UP/DN RBIAS Vss 8 CK LS7184 UP/DN RBIAS 15 CLK A EN C OD ER CK-DN 8 4 40193 V DD Vss 3 8 FIGURE 6A. TYPICAL APPLICATION FOR LS7183 IN x4 MODE FIGURE 6B. TYPICAL APPLICATION FOR LS7184 WITH MODE SELECTION 7183/84-082301-4