LS7084N

LSI/CSI UL LS7083N LS7084N ® LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 (631) 271-0400 FAX (631) 271-0405 A3800 June 2015 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-062315 -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); LS7083NS, LS7084NS (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 16 V Voltage at any input VIN VSS-0.3 to VDD+0.3 V TA -20 to +85 ºC TSTG -55 to 150 ºC Operating temperature Storage temperature DC ELECTRICAL CHARACTERISTICS: VALUE UNITS (Unless otherwise specified VDD = 3V to 12V and TA = -20ºC to +85ºC) PARAMETER SYMBOL MIN Supply Voltage VDD TYP MAX UNITS CONDITION 3 - 12 V Supply Current IDD - 1.5 1.65 mA Logic 0 Vml - - 0.5 V Logic 1 Vmh VDD - 0.5 - - V Logic Float Vmf (VDD/2) - 0.5 VDD/2 (VDD/2) + 0.5 V - Logic 0 Input Current Iml - 2.2 4.2 μA VDD = 3V Iml - 3.5 6.9 μA VDD = 5V VDD = 12V, all input frequencies=0 Hz and RBIAS = 2MΩ MODE INPUT: Logic 1 Input Current - Iml - 8.3 16.2 μA VDD = 12V Imh - -2 -9.8 μA VDD = 3V Imh - -3.4 -6.6 μA VDD = 5V Imh - -8.2 -16 μA VDD = 12V A,B INPUTS: Logic 0 VABl - - 0.25VDD V - Logic 1 VABh 0.7VDD - - V - Input Current IABlk - 0 10 nA - RB 2K - 10M Ω - Iol - -3.2 - mA Iol - -4.8 - mA RBIAS INPUT: External Resistor ALL OUTPUTS: Sink Current Source Current Iol - -7.2 - mA Ioh - 1.7 - mA Ioh - 2.2 - mA Ioh - 3.1 - mA TYP MAX UNITS CONDITION TRANSIENT CHARACTERISTICS (TA = -20ºC to +85ºC) PARAMETER SYMBOL MIN TOW 540 ns VDD = 3V TOW 180 ns VDD = 5V TOW 60 ns VDD = 12V TVD - 450 - TVD - 200 - VDD = 5V TVD - 90 - VDD = 12V Phase Delay TPS TVD+TOW Pulse Width TPW 2TPS Frequency fA,B - Input to output Delay TDS - TDS TDS Output Clock Pulse Width A,B INPUTS: Validation Delay 7083N/7084N‐062315‐2 ∞ VDD = 3V s - ∞ s - 1/(2TPW) Hz - 490 565 ns VDD = 3V - 220 345 ns VDD = 5V - 125 135 ns VDD = 12V -   The information included herein is believed to be accurate and reliable. However LSI Computer Systems, Inc assumes no responsibilities to inaccuracies, or to any infringements of patent rights of others which may result from its use.   7083N/84N‐062315‐3     Figure 4. TOW vs. RBIAS (R in KΩ) Figure 5. TOW vs. RBIAS (R in MΩ)     Figure 6A. Typical application for 7083N in x4 mode Figure 6B. Typical application for LS7084N in x2 mode Figure 7. Rotary encoder control of digital potentiometer   7083N/84N-062315-4