M1020/21
Integrated
Circuit
Systems, Inc.
VCSO BASED
CLOCK PLL
P r o d u c t D a t a S h e e t
See Table 6, Example External Loop Filter Component
Values on pg. 7.
PLL Simulator Tool Available
A free PC software utility is available on the ICS website
(www.icst.com). The M2000 Timing Modules PLL
Simulator is a downloadable application that simulates
PLL jitter and wander transfer characteristics. This
enables the user to set appropriate external loop
component values in a given application.
PLL bandwidth is affected by loop filter component
values, the “M” value, and the “PLL Loop Constants”
listed in AC Characteristics on pg. 9.
The MR_SEL3:0 settings can be used to actively change
PLL loop bandwidth in a given application. See “M and
R Divider Look-Up Tables (LUT)” on pg. 3.
For guidance on device or loop filter implementa-
tion, contact CMBU (Commercial Business Unit)
Product Applications at (508) 852-5400.
1
Example External Loop Filter Component Values
for M1020-yz-155.5200 and M1021-yz-155.5200
VCSO Parameters: K
= 200kHz/V, R = 100k
Ω
(pin NBW = 0), VCSO Bandwidth = 700kHz.
VCO
IN
Device Configuration
Example External Loop Filter Comp. Values Nominal Performance Using These Values
MR_SEL3:0 MDiv NBW
FREF
FVCSO
RLOOP
CLOOP
RPOST
CPOST
PLL Loop Damping Passband
Bandwidth
315Hz
Factor Peaking(dB)
(MHz)
(MHz)
19.44 2
38.88 3
77.76 4
77.76 5
155.52 4
155.52 5
155.52
155.52
155.52
155.52
155.52
155.52
0 0 0 0
0 0 0 1 16
0 1 0 1
8
0
0
0
0
0
0
5.4
6.7
5.4
6.0
6.7
6.2
0.07
0.05
0.07
0.05
0.05
0.05
6.8kΩ
12kΩ
6.8kΩ
22kΩ 4.7µF
12kΩ 10µF
47kΩ 2.2µF
10µF
10µF
10µF
82kΩ
82kΩ
82kΩ
82kΩ
82kΩ
82kΩ
1000pF
1000pF
1000pF
1000pF
1000pF
1000pF
270Hz
8
315Hz
0 1 1 0 32
1 0 1 0 16
1 0 1 1 64
250Hz
270Hz
266Hz
Table 6: Example External Loop Filter Component Values
Note 1: KVCO , VCSO Bandwidth, M Divider Value, and External Loop Filter Component Values determine Loop Bandwidth, Damping Factor,
and Passband Peaking. For PLL Simulator software, go to www.icst.com.
Note 2: This row is for the M1020 only.
Note 3: This row is for the M1021 only.
Note 4: Optimal for system clock filtering.
Note 5: Optimal for loop timing mode (LOL or Hitless Switching should not be used).
1
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter
Rating
Unit
VI
Inputs
-0.5 to VCC +0.5
V
VO
VCC
TS
Outputs
-0.5 to VCC +0.5
4.6
V
V
Power Supply Voltage
Storage Temperature
-45 to +100
oC
Table 7: Absolute Maximum Ratings
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the
device. These ratings are stress specifications only. Functional operation of product at these conditions
or any conditions beyond those listed in Recommended Conditions of Operation, DC Characteristics, or
AC Characteristics is not implied. Exposure to absolute maximum rating conditions for extended periods
may affect product reliability
.
RECOMMENDED CONDITIONS OF OPERATION
Symbol Parameter
Min
Typ
Max Unit
3.135
3.3
3.465
VCC
Positive Supply Voltage
V
TA
Ambient Operating Temperature
oC
oC
0
Commercial
Industrial
+70
+85
-40
Table 8: Recommended Conditions of Operation
M1020/21 Datasheet Rev 1.0
7 of 10
Revised 28Jul2004
Integrated Circuit Systems, Inc. ● Networking & Communications ● www.icst.com ● tel (508) 852-5400