LS7083NS‐14
June 2013
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 (V
DD
– V
SS
)
LS7083NS-14
(SOIC) –
See Figure 1.
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:
V
DD
(Pin 2)
Supply voltage positive terminal.
RBIAS (Pin 3)
Input for external component connection. A resistor connected between this input and
V
SS
adjusts the output clock pulse width (T
OW
). For proper operation, the output clock
pulse width must be less than or equal to the A, B pulse separation (T
OW
≤
T
PS
).
V
SS
(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).
The Mode input logic levels selects resolutions as follows:
Logic 0 = x1 Float = x2 Logic 1 = x4
7083NS-14-062713-1
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.
.
LSI [ LSI COMPUTER SYSTEMS ]
