IDT5992A Datasheet, PDF (2/8 Pages) Integrated Device Technology – PROGRAMMABLE SKEW PLL CLOCK DRIVER TURBOCLOCK-TM

IDT5992A
PROGRAMMABLE SKEW PLL CLOCK DRIVER TURBOCLOCK
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
PIN CONFIGURATION
3F1
4F0
4F1
VDDQ/PE
VDDN
4Q1
4Q0
GND
GND
4 3 2 1 32 31 30
5
29
6
28
7
27
8
26
9
25
10
24
11
23
12
22
13
21
14 15 16 17 18 19 20
2F0
GND/sOE
1F1
1F0
VDDN
1Q0
1Q1
GND
GND
PLCC
TOP VIEW
ABSOLUTE MAXIMUM RATINGS⁽¹⁾
Symbol
Description
Max
Unit
Supply Voltage to Ground
–0.5 to +7 V
VI
DC Input Voltage
–0.5 to +7 V
Maximum Power Dissipation (TA = 85°C)
0.8
W
TSTG Storage Temperature
–65 to +150 °C
NOTE:
1. Stresses beyond those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. These are stress ratings 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-rated conditions for extended periods may affect device reliability.
CAPACITANCE(TA = +25°C, f = 1MHz, VIN = 0V)
Parameter Description
Typ. Max. Unit
CIN
Input Capacitance
5
7
pF
NOTE:
1. Capacitance applies to all inputs except TEST, FS, and nF1:0.
PIN DESCRIPTION
Pin Name
Type
Description
REF
IN
Reference Clock Input
FB
IN
Feedback Input
TEST ⁽¹⁾
IN
When MID or HIGH, disables PLL (except for conditions of Note 1). REF goes to all outputs. Skew selections (see Control
GND/ sOE ⁽¹⁾
IN
Summary Table) remain in effect. Set LOW for normal operation.
Synchronous Output Enable. When HIGH, it stops clock outputs (except 3Q0 and 3Q1) in a LOW state - 3Q0 and 3Q1 may be used as
the feedback signal to maintain phase lock. When TEST is held at MID level and GND/sOE is HIGH, the nF[1:0] pins act as output disable
controls for individual banks when nF[1:0] = LL. Set GND/sOE LOW for normal operation.
VDDQ/PE
IN
Selectable positive or negative edge control. When LOW/HIGH the outputs are synchronized with the negative/positive edge of the
reference clock.
nF[1:0]
IN
3-level inputs for selecting 1 of 9 skew taps or frequency functions
FS
IN
Selects appropriate oscillator circuit based on anticipated frequency range. (See PLL Programmable Skew Range.)
nQ[1:0]
OUT
Four banks of two outputs with programmable skew
VDDN
PWR
Power supply for output buffers
VDDQ
PWR
Power supply for phase locked loop and other internal circuitry
GND
PWR
Ground
NOTE:
1.When TEST = MID and GND/sOE = HIGH, PLL remains active with nF[1:0] = LL functioning as an output disable control for individual output banks. Skew selections remain
in effect unless nF[1:0] = LL.
PROGRAMMABLE SKEW
Output skew with respect to the REF input is adjustable to compensate
for PCB trace delays, backplane propagation delays or to accommodate
requirements for special timing relationships between clocked compo-
nents. Skew is selectable as a multiple of a time unit tU which is of the
order of a nanosecond (see PLL Programmable Skew Range and Resolution
Table). There are nine skew configurations available for each output
pair. These configurations are chosen by the nF1:0 control pins. In order
to minimize the number of control pins, 3-level inputs (HIGH-MID-LOW)
are used, they are intended for but not restricted to hard-wiring. Undriven
3-level inputs default to the MID level. Where programmable skew is
not a requirement, the control pins can be left open for the zero skew
default setting. The Control Summary Table shows how to select specific
skew taps by using the nF1:0 control pins.
2