MICREL SY10EL34, SY10EL34L, SY100EL34, SY100EL34L Datasheet
5V/3.3V ÷2, ÷4, ÷8 CLOCK
GENERATION CHIP
ClockWorks™
SY10EL34/L
SY100EL34/L
FEATURES
■ 3.3V and 5V power supply options
■ 50ps output-to-output skew
■ Synchronous enable/disable
■ Master Reset for synchronization
■ Internal 75K
Ω input pull-down resistors
■ Available in 16-pin SOIC package
PIN CONFIGURATION/BLOCK DIAGRAM
VCC
Q0
Q0
VCC
Q1
Q1
VCC
Q2
Q2
1
2
3
4
5
6
7
8
Q
÷2
R
Q
R
Q
R
Q D
÷4
÷8
SOIC
TOP VIEW
16
EN
15
14
11
10
13
12
NC
CLK
CLK
V
BB
MR
9
EE
V
R
DESCRIPTION
The SY10/100EL34/L are low skew ÷2, ÷4, ÷8 clock
generation chips designed explicitly for low skew clock
generation applications. The internal dividers are
synchronous to each other, therefore, the common output
edges are all precisely aligned. The devices can be driven
by either a differential or single-ended ECL or, if positive
power supplies are used, PECL input signal. In addition,
by using the V
coupled into the device. If a single-ended input is to be
used, the VBB output should be connected to the CLK
input and bypassed to ground via a 0.01µF capacitor.
The VBB output is designed to act as the switching
reference for the input of the EL34/L under single-ended
input conditions. As a result, this pin can only source/
sink up to 0.5mA of current.
The common enable (EN) is synchronous so that the
internal dividers will only be enabled/disabled when the
internal clock is already in the LOW state. This avoids
any chance of generating a runt clock pulse on the
internal clock when the device is enabled/disabled as
can happen with an asynchronous control. An internal
runt pulse could lead to losing synchronization between
the internal divider stages. The internal enable flip-flop is
clocked on the falling edge of the divider stages. The
internal enable flip-flop is clocked on the falling edge of
the input clock, therefore, all associated specification
limits are referenced to the negative edge of the clock
input.
Upon start-up, the internal flip-flops will attain a random
state; the master reset (MR) input allows for the
synchronization of the internal dividers, as well as for
multiple EL34/Ls in a system.
BB output, a sinusoidal source can be AC-
PIN NAMES
1
Pin Function
CLK Differential Clock Inputs
EN Synchronous Enable
MR Master Reset
VBB Reference Output
Q0 Differential ÷2 Outputs
Q1 Differential ÷4 Outputs
Q
2 Differential ÷8 Outputs
Rev.: F Amendment: /0
Issue Date: August, 1998
Micrel
TRUTH TABLE
CLK EN MR Function
Z L L Divide
ZZ H L Hold Q0–2
X X H Reset Q0–2
NOTE:
Z = LOW-to-HIGH transition
ZZ = HIGH-to-LOW transition
ClockWorks™
SY10EL34/L
SY100EL34/L
DC ELECTRICAL CHARACTERISTICS
(1)
VEE = VEE (Min.) to VEE (Max.); VCC = GND
A = –40°CTA = 0°CTA = +25°CTA = +85°C
T
Symbol Parameter Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Unit
EE Power Supply 10EL — — 49 — — 49 — — 49 — — 49 mA
I
Current 100EL — — 49 — — 49 — — 49 — — 54
BB Output Reference 10EL –1.43 — –1.30 –1.38 — –1.27 –1.35 — –1.25 –1.31 — –1.19 V
V
Voltage 100EL –1.38 — –1.26 –1.38 — –1.26 –1.38 — –1.26 –1.38 — –1.26
IH Input High Current — — 150 — — 150 — — 150 — — 150 µA
I
NOTE:
1. Parametric values specified at: 5 volt Power Supply Range 100EL34 Series: -4.2V to -5.5V.
10EL34 Series -4.75V to -5.5V.
3 volt Power Supply Range 10/100EL34L Series: -3.0V to -3.8V.
AC ELECTRICAL CHARACTERISTICS
(1)
VEE = VEE (Min.) to VEE (Max.); VCC = GND
TA = –40°CTA = 0°CTA = +25°CTA = +85°C
Symbol Parameter Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Unit
PLH Propagation Delay to ps
t
tPHL Output CLK 960 1100 1200 960 1100 1200 960 1100 1200 960 1100 1200
MR 650 800 1010 650 800 1010 650 800 1010 650 800 1010
tskew Within-Device Skew
tS Set-up Time EN 400 — — 400 — — 400 — — 400 — — ps
tH Hold Time EN 200 — — 200 — — 200 — — 200 — — ps
VPP Minimum Input Swing
VCMR Common Mode Range
r Output Rise/Fall Times 275 400 525 275 400 525 275 400 525 275 400 525 ps
t
tf Q (20% – 80%)
NOTES:
1. Parametric values specified at: 5 volt Power Supply Range 100EL34 Series: -4.2V to -5.5V.
2. Skew is measured between outputs under identical transitions.
3. Minimum input swing for which AC parameters are guaranteed. The device will function reliably with differential inputs down to 100mV.
4. The CMR range is referenced to the most positive side of the differential input signal. Normal operation is obtained if the HIGH level falls within the specified
range and the peak-to-peak voltage lies between VPP min. and 1V. The lower end of the CMR range varies 1:1 with VEE. The numbers in the spec table
assume a nominal VEE = –3.3V. Note for PECL operation, the VCMR (min) will be fixed at 3.3V – IVCMR (min)I.
(2)
— — 50 — — 50 — — 50 — — 50 ps
(3)
250 — — 250 — — 250 — — 250 — — mV
(4)
–1.3 — –0.4 –1.4 — –0.4 –1.4 — –0.4 –1.4 — –0.4 V
10EL34 Series -4.75V to -5.5V.
3 volt Power Supply Range 10/100EL34L Series: -3.0V to -3.8V.
2
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