LS7083NS-14 Datasheet, PDF (1/4 Pages) LSI Computer Systems – QUADRATURE CLOCK CONVERTER

LS7083NS‐14
QUADRATURE CLOCK CONVERTER
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)
• LS7083NS-14 (SOIC) – See Figure 1.
June 2013
PIN ASSIGNMENT
TOP VIEW
Applications:
• Interface incremental encoders to Up/Down Counters
(See Figure 6A and 6B)
DESCRIPTION:
The LS7083NS-14 is a CMOS quadrature clock converter. Quadrature clocks derived
from optical or magnetic encoders, when applied to the A and B inputs of the
LS7083NS-14 are converted to strings of Up Clocks and Down Clocks. These outputs
can be interfaced directly with standard Up/Down counters for direction and position
sensing of the encoder.
INPUT/OUTPUT DESCRIPTION:
VDD (Pin 2)
Supply voltage positive terminal.
RBIAS (Pin 3)
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).
VSS (Pin 4)
Supply voltage negative terminal.
A (Pin 5)
Quadrature Clock Input A. This input has a filter circuit to validate input logic level and
eliminate encoder dither.
B (Pin 10)
Quadrature Clock Input B. This input has a filter circuit identical to input A.
Mode (Pin 11)
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).
FIGURE 1.
DNCK (Pin 12)
This is the DOWN Clock Output. This output
consists of low-going pulses generated when A
input lags the B input.
UPCK (Pin 13)
This is the UP Clock Output. This output consists of
low-going pulses generated when A input leads the
B input.
.
The Mode input logic levels selects resolutions as follows:
Logic 0 = x1 Float = x2 Logic 1 = x4
7083NS-14-062713-1