IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
INDUSTRIAL TEMPERATURE RANGE
SINGLE OUTPUT
CLOCK GENERATOR
IDT5V926
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 <500µA)
µ
Available in TSSOP package
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 50Ω.
DESCRIPTION:
APPLICATIONS:
•
•
•
•
•
•
Gigabit ethernet
Router
Network switches
SAN
Instrumentation
Fibre channel
FUNCTIONAL BLOCK DIAGRAM
OE
VCO DIVIDE
1/N
PHASE
DETECTOR
CHARGE
PUMP
LOOP
FILTER
VCO
Q
OUT
0
1
X1/REF
CRYSTAL
OSCILLATOR
X2
SELECT MODE
Q
REF
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
S1
S0
REFE
INDUSTRIAL TEMPERATURE RANGE
1
c
2003 Integrated Device Technology, Inc.
APRIL 2003
DSC
5405/4
IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
INDUSTRIAL TEMPERATURE RANGE
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
Description
Supply Voltage to Ground
Input Voltage
Output Current
Storage Temperature
Junction Temperature
Max.
– 0.5 to +4.6
– 0.5 to +4.6
±50
– 65 to +150
150
Unit
V
V
mA
°C
°C
REFE
X
1
/REF
X
2
V
DD
V
DDQ
GND
Q
REF
V
DDQ
1
2
3
4
5
6
7
8
TSSOP
TOP VIEW
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9
S
0
S
1
OE
GND
V
DDQ
GND
Q
OUT
V
DDQ
V
DD
/V
DDQ
V
I
I
O
T
STG
T
J
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
S[
1:0
]
OE
I
I
Description
Three level divider/mode select pins. Float to MID.
Output enable bar. Outputs Q
OUT
and Q
REF
are tristated when
HIGH. Set
OE
LOW for normal operation (has internal pull-
down).
Q
REF
enable input. Q
REF
stopped LOW when HIGH. When set
REFE
LOW, the Q
REF
is enabled (has internal pull-down).
Crystal oscillator input or clock input
Crystal oscillator output. Leave unconnected for clock input.
Output at N*REF frequency
Output at REF frequency
Power supply for the device outputs. Connect to V
DD
on PCB.
Power supply for the device core and inputs. Connect to V
DD
on PCB.
GND
PWR
Ground supply
REFE
X
1
/REF
X
2
Q
OUT
I
I
I
O
O
PWR
PWR
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 50Ω maximum equivalent series resonance.
Crystal tuning capacitors should be connected from X
1
/REF to GND and from
X
2
to GND.
Q
REF
V
DDQ
V
DD
DIVIDE SELECTION TABLE
(1)
S1
L
L
L
M
M
M
H
H
H
S0
L
M
H
L
M
H
L
M
H
Divide-by-N Value
2
3
4
4.25
5
6
6.25
8
TEST
Mode
PLL
PLL
PLL
PLL
PLL
PLL
PLL
PLL
TEST
(2)
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.
2
IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
INDUSTRIAL TEMPERATURE RANGE
COMMON OUTPUT FREQUENCY EXAMPLES (MHz)
Output
Input
FB Divide Selection S[
1:0
]
Output
Input
FB Divide Selection S[
1:0
]
48
24
LL
106.25
17
HL
60
10
MH
106.25
25
ML
64
16
LH
120
15
HM
72
12
MH
125
20
HL
75
25
LM
125
25
MM
80
10
HM
125
62.5
LL
90
15
MH
150
25
MH
100
20
MM
155.52
19.44
HM
OPERATING CONDITIONS
Symbol
V
DD
/V
DDQ
T
A
C
L
C
IN
Parameter
Power Supply Voltage
Operating Temperature
Output Load Capacitance
Input Capacitance, OE, F = 1MHz, V
IN
= 0V, T
A
= 25°C
Min.
3
- 40
—
—
Typ.
3.3
25
—
5
Max.
3.6
+85
15
7
Unit
V
°C
pF
pF
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= –40°C to +85°C, V
DD
/V
DDQ
= 3.3V ±0.3V
Symbol
V
IL
V
IH
V
IHH
V
IMM
V
ILL
I
3
I
IH
V
OL
V
OH
Parameter
Input LOW Voltage
Input HIGH Voltage
Input HIGH Voltage
Input MID Voltage
Input LOW Voltage
3-Level Input DC Current, S
[1:0]
Input HIGH Current
Output LOW Voltage
Output HIGH Voltage
Test Conditions
Min.
—
2
V
DD
- 0.6
V
DD
/2 - 0.3
—
—
- 50
- 200
—
—
—
2.4
Typ.
—
—
—
—
—
—
—
—
—
2
—
—
Max
0.8
—
—
V
DD
/2 + 0.3
0.6
+200
+50
—
100
4
0.4
—
Unit
V
V
V
V
V
µA
µA
mA
V
V
3-level input only
3-level input only
3-level input only
V
IN
= V
DD
V
IN
= V
DD
/2
V
IN
= GND
V
IN
= V
DD
V
IN
= V
DD
, S
[1:0]
= HH
I
OL
= 12mA
I
OH
= -12mA
HIGH Level
MID Level
LOW Level
OE, REFE
X
1
/REF
3
IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
INDUSTRIAL TEMPERATURE RANGE
POWER SUPPLY CHARACTERISTICS
Symbol
I
DD_PD
Parameter
Power Down Current
Test Conditions
(1)
V
DD
= Max.
S
[1:0]
= HH
OE
= L
;
X
1
/REF = L
All outputs unloaded
∆I
DD
I
DD
Supply Current per Input
Dynamic Supply Current
V
DD
= Max., V
IN
= 3V
V
DD
= 3.6V
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.
Min.
—
Typ.
—
Max
500
Unit
µA
—
—
—
—
30
130
µA
mA
AC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Symbol
t
R,
t
F
d
T
Parameter
Rise Time, Fall Time
Output/Duty Cycle
Test Conditions
0.8V to 2V
V
T
= V
DDQ
/2
F
OUT
= 106.25MHz
t
J
f
OUT
Cycle - Cycle Jitter
Output Frequency
F
OUT
= 125MHz
F
OUT
= 155.52MHz
—
Q
OUT
Q
REF
Q
OUT
Q
REF
Min.
—
—
45
40
- 100
- 75
- 75
48
Typ.
0.7
0.7
—
—
—
—
—
—
Max.
1.5
2
55
60
100
75
75
160
MHz
ps
%
Unit
ns
INPUT TIMING REQUIREMENTS
Symbol
t
R,
t
F
t
PWC
D
H
f
OSC
f
IN
Description
(1)
Maximum input rise and fall time, 0.8V to 2V
(2)
Input clock pulse, HIGH or LOW
(2)
Input duty cycle
(2)
XTAL oscillator frequency
Input frequency
(2)
Min.
—
2
10
—
48/N
Max.
10
—
90
40
160/N
Unit
ns/V
ns
%
MHz
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.
4
IDT5V926
SINGLE OUTPUT CLOCK GENERATOR
INDUSTRIAL TEMPERATURE RANGE
AC TEST LOADS AND WAVEFORMS
V
DD
150
Ω
OUTPUT
15pF
150
Ω
AC Test Load
3V
2V
V
TH
= V
D D
/2
0.8
0V
1ns
1ns
Input Test Waveform
V
DDQ
2V
V
TH
= V
D DQ
/2
0.8
0V
t
R
t
F
Output Waveform
5
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