ClockWorks™
SY10E195
PROGRAMMABLE
DELAY CHIP
SY100E195
FEATURES
DESCRIPTION
■ Up to 2ns delay range
The SY10/100E195 are programmable delay chips
(PDCs) designed primarily for clock de-skewing and timing
adjustment. They provide variable delay of a differential
ECL input transition.
The delay section consists of a chain of gates
organized as shown in the logic diagram. The first two
delay elements feature gates that have been modified to
have delays 1.25 and 1.5 times the basic gate delay of
approximately 80ps. These two elements provide the
■ Extended 100E VEE range of –4.2V to –5.5V
■ ≈20ps/digital step resolution
■ >1GHz bandwidth
■ On-chip cascade circuitry
■ 75KkΩ input pulldown resistor
■ Fully compatible with Motorola MC10E/100E195
■ Available in 28-pin PLCC package
E195 with
a
digitally-selectable resolution of
approximately 20ps. The required device delay is selected
by the seven address inputs D[0:6], which are latched
on-chip by a high signal on the latch enable (LEN) control.
If the LEN signal is either LOW or left floating, then the
latch is transparent.
Because the delay programmability of the E195 is
achieved by purely differential ECL gate delays, the
device will operate at frequencies of >1GHz, while
maintaining over 600mV of output swing.
PIN CONFIGURATION
The E195 thus offers very fine resolution, at very high
frequencies, selectable entirely from a digital input,
allowing for very accurate system clock timing.
An eighth latched input, D7, is provided for cascading
multiple PDCs for increased programmable range. The
cascade logic allows full control of multiple PDCs, at the
expense of only a single added line to the data bus for
each additional PDC, without the need for any external
gating.
25
24 23 22 21 20 19
D1
D0
26
27
28
1
18
17
16
15
14
13
12
NC
NC
VCC
VCCO
Q
LEN
VEE
IN
TOP VIEW
PLCC
J28-1
2
IN
3
Q
VBB
4
VCCO
5
6
7
8
9
10 11
PIN NAMES
Pin
Function
Signal Input
IN/IN
EN
Input Enable
D[0:7]
Mux Select Inputs
Signal Output
Q/Q
LEN
Latch Enable
SET MIN
SET MAX
CASCADE
Minimum Delay Set
Maximum Delay Set
Cascade Signal
Rev.: E
Amendment:/0
Issue Date: October, 1998
1