DS1045
PARALLEL PROGRAMMING
Parallel programming of the DS1045 is accomplished via the set of parallel inputs A0-A3 and B0-B3 as
shown in Figure 1. Parallel input A0-A3 and B0-B3 accept TTL levels and are used to set the delay
values of outputs OUTA and OUTB, respectively. Sixteen possible delay values between the minimum
9 ns delay and the maxi-mum delay of the DS1045-x device version can be selected using the parallel
programming inputs A0-A3 or B0-B3 (see Table 2, “Delay vs. Programmed Input”). For example, the
DS1045-3 outputs OUTA or OUTB and can be programmed to produce 16 possible delays between the
9 ns (minimum) and the 54 ns (maximum) in 3 ns increment levels.
For applications that do not require frequent reprogramming, the parallel inputs can be set using fixed
logic levels, as would be produced by jumpers, DIP switches, or TTL levels as produced by computer
systems. Maximum flexibility in parallel programming can be achieved when inputs are set by computer-
generated data. By using the enable input pins for each respective programmed output and observing the
input setup (tDSE) and hold time (tDHE) requirements, data can be latched on an 8-bit bus. If the enable
pins, EA and EB , are not used to latch data, they should be set to a logic level 1. After each change in
the programmed delay value, a settling time (tEDV) or (tPDV) is required before the delayed output signal is
reliably produced. Since the DS1045 is a CMOS design, undefined input pins should be connected to
well defined logic levels and not left floating.
PART NUMBER TABLE Table 1
MAX DELAY
PART NUMBER
STEP ZERO DELAY
MAX DELAY TIME
TOLERANCE
DS1045-3
54 ns
9 ±=1 ns
±2.5 ns
DS1045-4
DS1045-5
69 ns
84 ns
9 ±=1 ns
9 ±=1 ns
±3.3 ns
±4.1 ns
NOTE:
Additional delay step times are available from Dallas Semiconductor by special order. Consult factory
for availability.
BLOCK DIAGRAM Figure 1
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DALLAS [ DALLAS SEMICONDUCTOR ]
