1
IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
INDUSTRIAL TEMPERATURE RANGE
APRIL 2003
2003 Integrated Device Technology, Inc.
DSC 5405/4
c
IDT5V926
INDUSTRIAL TEMPERATURE RANGE
SINGLE OUTPUT
CLOCK GENERATOR
FUNCTIONAL BLOCK DIAGRAM
DESCRIPTION:
The IDT5V926 is a low-cost, low skew, low jitter, and high-performance
clock synthesizer with a reference clock from lower frequency crystal or clock
input. It has been specially designed to interface with Gigabit Ethernet and
Fast Ethernet applications by providing a 125MHz clock from 25MHz input.
It can be programmed to provide output frequencies ranging from 48MHz
to 160MHz, with input frequencies ranging from 6MHz to 80MHz.
The IDT5V926 includes an internal RC filter that provides excellent jitter
characteristics and eliminates the need for external components. When
using the optional crystal input, the chip accepts a 10 - 40MHz fundamental
mode crystal with a maximum equivalent series resistance of 50
.
X1/REF
X2
CRYSTAL
OSCILLATOR
PHASE
DETECTOR
CHARGE
PUMP
LOOP
FILTER
VCO
SELECT MODE
Q
OUT
Q
REF
S1
S0
OE
VCO DIVIDE
1/N
REFE
0
1
FEATURES:
3V to 3.6V operating voltage
48MHz to 160MHz output frequency range
Input from fundamental crystal oscillator or external source
Internal PLL feedback (loading feedback output relative to
other outputs, adjusts propagation delay between REF
inputs and outputs)
Select inputs (S
[1:0]
) for FB divide selection (multiply ratio of
2, 3, 4, 4.25, 5, 6, 6.25, and 8)
Low jitter
PLL bypass for testing and power-down control (S1 = H, S0 =
H, powers part down <500
A)
Available in TSSOP package
APPLICATIONS:
Gigabit ethernet
Router
Network switches
SAN
Instrumentation
Fibre channel
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
2
INDUSTRIAL TEMPERATURE RANGE
IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
REFE
X
1
/REF
X
2
V
DD
V
DDQ
Q
REF
V
DDQ
S
1
OE
GND
V
DDQ
GND
Q
OUT
V
DDQ
S
0
GND
PIN CONFIGURATION
TSSOP
TOP VIEW
CRYSTAL SPECIFICATION
The crystal oscillators should be fundamental mode quartz crystals:
overtone crystals are not suitable. Crystal frequency should be specified
for parallel resonance with 50
maximum equivalent series resonance.
Crystal tuning capacitors should be connected from X
1
/REF to GND and from
X
2
to GND.
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
Description
Max.
Unit
V
DD
/V
DDQ
Supply Voltage to Ground
0.5 to +4.6
V
V
I
Input Voltage
0.5 to +4.6
V
I
O
Output Current
50
mA
T
STG
Storage Temperature
65 to +150
C
T
J
Junction Temperature
150
C
NOTE:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
PIN DESCRIPTION
Pin Name Type
Description
S[
1:0
]
I
Three level divider/mode select pins. Float to MID.
OE
I
Output enable bar. Outputs Q
OUT
and Q
REF
are tristated when
HIGH. Set OE LOW for normal operation (has internal pull-
down).
REFE
I
Q
REF
enable input. Q
REF
stopped LOW when HIGH. When set
REFE LOW, the Q
REF
is enabled (has internal pull-down).
X
1
/REF
I
Crystal oscillator input or clock input
X
2
I
Crystal oscillator output. Leave unconnected for clock input.
Q
OUT
O
Output at N*REF frequency
Q
REF
O
Output at REF frequency
V
DDQ
PWR
Power supply for the device outputs. Connect to V
DD
on PCB.
V
DD
PWR
Power supply for the device core and inputs. Connect to V
DD
on PCB.
GND
PWR
Ground supply
NOTES:
1. H = HIGH
M = MEDIUM
L = LOW
2. Test mode for low frequency testing. In this mode, REF clock bypasses the VCO (VCO powered down) and the crystal oscillator is powered down.
DIVIDE SELECTION TABLE
(1)
S1
S0
Divide-by-N Value
Mode
L
L
2
PLL
L
M
3
PLL
L
H
4
PLL
M
L
4.25
PLL
M
M
5
PLL
M
H
6
PLL
H
L
6.25
PLL
H
M
8
PLL
H
H
TEST
TEST
(2)
3
IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
INDUSTRIAL TEMPERATURE RANGE
COMMON OUTPUT FREQUENCY EXAMPLES (MHz)
Output
48
60
64
72
75
80
90
100
Input
24
10
16
12
25
10
15
20
FB Divide Selection S[
1:0
]
LL
M H
LH
M H
LM
H M
M H
M M
Output
106.25
106.25
120
125
125
125
150
155.52
Input
17
25
15
20
25
62.5
25
19.44
FB Divide Selection S[
1:0
]
HL
ML
H M
HL
M M
LL
M H
H M
OPERATING CONDITIONS
Symbol
Parameter
Min.
Typ.
Max.
Unit
V
DD
/V
DDQ
Power Supply Voltage
3
3.3
3.6
V
T
A
Operating Temperature
- 40
25
+85
C
C
L
Output Load Capacitance
--
--
15
pF
C
IN
Input Capacitance, OE, F = 1MHz, V
IN
= 0V, T
A
= 25C
--
5
7
pF
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= 40C to +85C, V
DD
/V
DDQ
= 3.3V 0.3V
Symbol
Parameter
Test Conditions
Min.
Typ.
Max
Unit
V
IL
Input LOW Voltage
--
--
0.8
V
V
IH
Input HIGH Voltage
2
--
--
V
V
IHH
Input HIGH Voltage
3-level input only
V
DD
- 0.6
--
--
V
V
IMM
Input MID Voltage
3-level input only
V
DD
/2 - 0.3
--
V
DD
/2 + 0.3
V
V
ILL
Input LOW Voltage
3-level input only
--
--
0.6
V
V
IN
= V
DD
HIGH Level
--
--
+200
I
3
3-Level Input DC Current, S
[1:0]
V
IN
= V
DD
/2
MID Level
- 50
--
+50
A
V
IN
= GND
LOW Level
- 200
--
--
I
IH
Input HIGH Current
V
IN
= V
DD
OE, REFE
--
--
100
A
V
IN
= V
DD
, S
[1:0]
= HH
X
1
/REF
--
2
4
mA
V
OL
Output LOW Voltage
I
OL
= 12mA
--
--
0.4
V
V
OH
Output HIGH Voltage
I
OH
= -12mA
2.4
--
--
V
4
INDUSTRIAL TEMPERATURE RANGE
IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
POWER SUPPLY CHARACTERISTICS
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
Max
Unit
I
DD_PD
Power Down Current
V
DD
= Max.
--
--
500
A
S
[1:0]
= HH
OE = L
;
X
1
/REF = L
All outputs unloaded
I
DD
Supply Current per Input
V
DD
= Max., V
IN
= 3V
--
--
30
A
I
DD
Dynamic Supply Current
V
DD
= 3.6V
--
--
130
mA
S
[1:0]
= LL
OE = L
F
OUT
= 150MHz
All outputs unloaded
NOTE:
1. For conditions shown as Min. or Max., use the appropriate values specified under DC Electrical Characteristics.
AC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
t
R,
t
F
Rise Time, Fall Time
0.8V to 2V
Q
OUT
--
0.7
1.5
ns
Q
REF
--
0.7
2
d
T
Output/Duty Cycle
V
T
= V
DDQ
/2
Q
OUT
45
--
55
%
Q
REF
40
--
60
F
OUT
= 106.25MHz
- 100
--
100
t
J
Cycle - Cycle Jitter
F
OUT
= 125MHz
- 75
--
75
ps
F
OUT
= 155.52MHz
- 75
--
75
f
OUT
Output Frequency
--
48
--
160
MHz
INPUT TIMING REQUIREMENTS
Symbol
Description
(1)
Min.
Max.
Unit
t
R,
t
F
Maximum input rise and fall time, 0.8V to 2V
(2)
--
10
ns/V
t
PWC
Input clock pulse, HIGH or LOW
(2)
2
--
ns
D
H
Input duty cycle
(2)
10
90
%
f
OSC
XTAL oscillator frequency
--
40
MHz
f
IN
Input frequency
(2)
48/N
160/N
MHz
NOTES:
1. Where pulse width implied by D
H
is less than the t
PWC
limit, t
PWC
limit applies,
2. When using a clock input.
5
IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
INDUSTRIAL TEMPERATURE RANGE
AC TEST LOADS AND WAVEFORMS
15pF
150
OUTPUT
V
DD
150
2V
V
TH
= V
D D
/2
0V
1ns
3V
1ns
0.8
2V
0V
t
R
t
F
0.8
V
D D Q
V
TH
= V
D DQ
/2
AC Test Load
Input Test Waveform
Output Waveform
PDF 
ZIP