ETC QS5935Q

QS5935
LOW SKEW CMOS PLL CLOCK DRIVER WITH INTEGRATED LOOP FILTER
INDUSTRIAL TEMPERATURE RANGE
LOW SKEW CMOS PLL
CLOCK DRIVER WITH
INTEGRATED LOOP FILTER
QS5935
FEATURES:
DESCRIPTION
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The QS5935 Clock Driver uses an internal phase locked loop (PLL)
to lock low skew outputs to a reference clock input. Five outputs are
available: Q0–Q4. Careful layout and design ensure <500ps skew between
the Q0–Q 4. The QS5935 includes an internal RC filter which provides
excellent jitter characteristics and eliminates the need for external components. The PLL can also be disabled by the PLL_EN signal to allow low
frequency or DC testing. The QS5935 is designed for use in cost sensitive
high-performance computing systems, workstations, multi-board computers, networking hardware, and mainframe systems. Several can be used
in parallel or scattered throughout a system for guaranteed low skew,
system-wide clock distribution networks. In the QSOP package, the QS5935
clock driver represents the best value in small form factor, high-performance
clock management products.
5V operation
Five low noise CMOS level outputs
<500ps output skew, Q0–Q4
Outputs 3-state and reset while OE/RST low
PLL disable feature for low frequency testing
Internal loop filter RC network
Balanced drive outputs ±36mA
80MHz maximum frequency
Available in QSOP package
FUNCTIONAL BLOCK DIAGRAM
PLL_EN
/2
0
1
CLK_IN
Q0
Q1
PLL
Q2
FEEDBAC K
Q3
Q4
OE/RST
INDUSTRIAL TEMPERATURE RANGE
JULY 2000
1
c
2000
Integrated Device Technology, Inc.
DSC-5816/-
QS5935
LOW SKEW CMOS PLL CLOCK DRIVER WITH INTEGRATED LOOP FILTER
INDUSTRIAL TEMPERATURE RANGE
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
Symbol
Rating
AVDD, VDD Supply Voltage to Ground
GND
1
20
Q4
OE/RST
2
19
N/C
FEEDBACK
3
18
G ND
AV DD
4
17
Q3
VDD
5
16
VDD
AG ND
6
15
Q2
CLK_IN
7
14
G ND
VDD
8
13
PLL_EN
GND
9
12
G ND
10
11
Q1
Q0
SO 20-8
DC Input Voltage VIN
Max.
–0.5 to +7
V
0.5
–65 to +150
W
°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.
CAPACITANCE (TA = 25° C, f = 1MHz, VIN = 0V) (1)
Pins
CIN
COUT
Typ.
3
Max.
4
Unit
pF
4
5
pF
NOTE:
1. Capacitance is characterized but not tested.
QSOP
TOP VIEW
PIN DESCRIPTION
Pin Name
Unit
V
–0.5 to VDD+0.5
Maximum Power Dissipation (TA = 85°C)
Storage Temperature Range
TSTG
(1)
I/O
Description
CLK_IN
I
Reference clock input
FEEDBACK
I
External feedback provides flexibility for different output frequency relationships
Q0 -Q4
O
Clock outputs
OE/RST
I
PLL_EN
I
VDD
—
Output enable/asynchronous reset. Resets all output registers. When 0, all outputs are held in a tri-stated condition. When 1,
outputs are enabled.
When 1, PLL is enabled. When 0, PLL is disabled and the output for Q 0 -Q4 will be CLK_IN/2 in frequency. This allows the
CLK_IN input to be single-stepped for system debug.
Power supply for output buffers
AVDD
—
Power supply for phase lock loop and other internal circuitries
GND
—
Ground supply for output buffers
AGND
—
Ground supply for phase lock loop and other internal circuitries
2
QS5935
LOW SKEW CMOS PLL CLOCK DRIVER WITH INTEGRATED LOOP FILTER
INDUSTRIAL TEMPERATURE RANGE
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: TA = –40°C to +85°C, AVDD/VDD = 5.0V ± 10%
Symbol
VIH
Parameter
Input HIGH Voltage
Conditions
Guaranteed Logic HIGH Level
Min.
2
Typ.
—
Max.
—
Unit
V
VIL
Input LOW Voltage
Guaranteed Logic LOW Level
—
—
0.8
V
VOH
Output HIGH Voltage
IOH = −36mA
VDD – 0.75
—
—
V
IOH = −100µA
VDD – 0.2
—
—
V
VDD = Min., IOL = 36mA
—
—
0.45
V
VDD = Min., IOL = 100µA
—
—
0.2
V
—
100
—
mV
—
—
±5
µA
—
—
±5
µA
VOL
Output LOW Voltage
VH
Input Hysteresis
IOZ
Output Leakage Current
IIN
Input Leakage Current
—
VOUT = VDD or GND,
VDD = Max., Outputs Disabled
VIN = AVDD or GND, AVDD = Max.
POWER SUPPLY CHARACTERISTICS
Symbol
IDDQ
Parameter
Quiescent Power Supply Current
∆IDD
Power Supply Current per Input HIGH
Test Conditions
VDD = Max., OE/RST = LOW,
CLK_IN = LOW, All outputs unloaded
VDD = Max., VIN = 3.4V
IDDD
Dynamic Power Supply Current (1)
VDD = Max., CL = 0pF
Typ.
—
Max.
1
Unit
mA
0.7
1.5
mA
—
0.4
mA/MHz
NOTE:
1. This value is guaranteed but not tested.
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
Symbol
tSKR
Parameter (1)
Output Skew Between Rising Edges, Q0-Q4 (2,3)
Min.
—
Typ.
—
Max.
500
Unit
ps
tSKF
Output Skew Between Falling Edges, Q0-Q4 (2,3)
—
—
500
ps
tPW
Pulse Width, Q0-Q4
TCYC/2 − 0.4
—
TCYC/2 + 0.4
ns
tJ
Cycle-to-Cycle Jitter (2,5)
− 0.15
—
+0.15
ns
− 500
—
+500
ps
(2,6)
tPD
CLK_IN to Feedback Delay
tLOCK
CLK_IN to Phase Lock
—
—
10
ms
tPZH
tPZL
tPHZ
tPLZ
tR, tF
Output Enable Time, OE/RST LOW to HIGH (4)
0
—
14
ns
Output Disable Time, OE/RST HIGH to LOW (2,4)
0
—
14
ns
Output Rise/Fall Times, 0.2VDD ∼ 0.8VDD (2)
—
—
2.5
ns
tR, tF
Maximum Rise/Fall Times, 0.8V to 2V
—
—
3
ns
FI
Input Clock Frequency
10
—
80
MHz
2
—
—
ns
25
—
75
%
tPWC
Input Clock Pulse, HIGH or LOW
DH
Duty Cycle, CLK_IN (7)
(7)
NOTES:
1. See Test Loads and Waveforms for test load and termination.
2. This parameter is guaranteed by characterization but not tested.
3. Skew specifications apply under identical environments (loading, temperature, VDD, device speed grade).
4. Measured in open loop mode PLL_EN = 0.
5. Jitter is characterized using an oscilloscope, Q output at 20MHz. Measurement is taken one cycle after jitter.
6. tPD measured at device inputs at 1.5V, Q output at 80MHz.
7. Input timing requirements are guaranteed by design but not tested. Where pulse width implied by DH is less than tPWC limit, tPWC limit applies.
3
QS5935
LOW SKEW CMOS PLL CLOCK DRIVER WITH INTEGRATED LOOP FILTER
INDUSTRIAL TEMPERATURE RANGE
AC TEST LOADS AND WAVEFORMS
VDD
300 Ω
100 Ω
7.0V
OU TP UT
OU TP UT
300 Ω
30p F
100 Ω
TEST CIRCUIT 1
TEST CIRCUIT 2
1.0ns
1.0ns
tR
3.0V
VDD
2.0V
0.8V D D
V th = 1 .5V
0.5V DD
0.8V
0.2V D D
0V
0V
tF
tP W
TTL INPUT TEST WAVEFORM
CMOS OUTPUT WAVEFORM
EN A BL E
DISA B LE
3V
1.5V
CO NTRO L
0V
INPU T
tPL Z
t PZ L
OU TP UT
3.5V
NO R M AL LY
LOW
SW ITCH
0.5V DD
CLO SED
0.3V
VO L
0.3V
VOH
tPH Z
tPZ H
SW ITCH
OU TP UT
OP EN
0.5V D D
NO R M AL LY
0V
HIGH
ENABLE AND DISABLE TIMES
TEST CIRCUIT 1 is used for output enable/disable parameters.
TEST CIRCUIT 2 is used for all other timing parameters.
4
QS5935
LOW SKEW CMOS PLL CLOCK DRIVER WITH INTEGRATED LOOP FILTER
INDUSTRIAL TEMPERATURE RANGE
AC TIMING DIAGRAM
CLK_IN
tP D
FE ED BA CK
tJ
Q
tS K F
Q 0 -Q 4
NOTES:
1. AC Timing Diagram applies to Q output connected to FEEDBACK .
2. All parameters are measured at 0.5VDD except for tPD, which is measured at 1.5V
5
QS5935
LOW SKEW CMOS PLL CLOCK DRIVER WITH INTEGRATED LOOP FILTER
INDUSTRIAL TEMPERATURE RANGE
ORDERING INFORMATION
QS
XXXX
Device Type
X
Package
X
Process
Blank
Industrial (-40°C to +85°C)
Q
Quarter Size Outline Package (SO20-8)
5935
Low Skew CMOS PLL C lock Driver with Integrated
Loop Filter
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