5
INDUSTRIAL TEMPERATURE RANGE
IDT5T2110
2.5V ZERO DELAY PLL DIFFERENTIAL CLOCK DRIVER TERACLOCK
PIN DESCRIPTION, CONTINUED
Symbol I/O Type Description
REF_SEL I LVTTL(1) Reference clock select. When LOW, selects REF0 and REF0/VREF0. When HIGH, selects REF1 and REF1/VREF1.
nsOE I LVTTL(1) Synchronous output enable. When nsOE is HIGH, nQ and nQ are synchronously stopped. OMODE selects whether the outputs are
gated LOW/HIGH or tri-stated. When OMODE is HIGH, PE determines the level at which the outputs stop. When PE is LOW/HIGH,
the nQ is stopped in a HIGH/LOW state, while the nQ is stopped at a LOW/HIGH state. When OMODE is LOW, the outputs are tri-
stated. Set nsOE LOW for normal operation.
QFB O Adjustable(2) Feedback clock output
QFB O Adjustable(2) Complementary feedback clock output
nQ O Adjustable(2) Clock outputs
nQ O Adjustable(2) Complementary clock outputs
RxS I 3-Level(3) Selects single-ended 2.5V LVTTL (HIGH), 1.8V LVTTL (MID) REF clock input or differential (LOW) REF clock input
TxS I 3-Level(3) Sets the drive strength of the output drivers and feedback inputs to be 2.5V LVTTL (HIGH), 1.8V LVTTL (MID) or eHSTL/HSTL (LOW)
compatible. Used in conjuction with VDDQ to set the interface levels.
PE I LVTTL(1) Selectable positive or negative edge control. When LOW/HIGH the outputs are synchronized with the negative/positive edge of the reference
clock (has internal pull-up).
nF[2:1] I LVTTL(1) Function select inputs for divide-by-2, divide-by-4, zero delay, or invert on each bank. (See Control Summary table.)
FBF[2:1] I LVTTL(1) Function select inputs for divide-by-2, divide-by-4, zero delay, or invert on the feedback bank (See Control Summary table)
FS I LVTTL(1) Selects appropriate oscillator circuit based on anticipated frequency range (See VCO Frequency Range Select table)
DS[1:0] I 3-Level(3) 3-level inputs for feedback input divider selection (See Divide Selection table)
PLL_EN I LVTTL(1) PLL enable/disable control. Set LOW for normal operation. When PLL_EN is HIGH, the PLL is disabled and REF[1:0] goes to all outputs.
PD I LVTTL(1) Power down control. When PD is LOW, the inputs are disabled and internal switching is stopped. OMODE selects whether the outputs
are gated LOW/HIGH or tri-stated. When OMODE is HIGH, PE determines the level at which the outputs stop. When PE is LOW/
HIGH, the nQ and QFB are stopped in a HIGH/LOW state, while the nQ and QFB are stopped in a LOW/HIGH state. When OMODE
is LOW, the outputs are tri-stated. Set PD HIGH for normal operation.
LOCK O LVTTL PLL lock indication signal. HIGH indicates lock. LOW indicates that the PLL is not locked and outputs may not be synchronized to the
inputs. The output will be 2.5V LVTTL. (For more information on application specific use of the LOCK pin, please see AN237.)
OMODE I LVTTL(1) Output disable control. Determines the outputs' disable state. Used in conjunction with nsOE and PD. (See Output Enable/Disable and
Powerdown tables.)
VDDQ PWR Power supply for output buffers. When using 2.5V LVTTL, VDDQ should be connected to VDD.
VDD PWR Power supply for phase locked loop, lock output, inputs, and other internal circuitry
GND PWR Ground
VCO FREQUENCY RANGE SELECT
FS(1) Min. Max. Unit
LOW 50 125 MHz
HIGH 100 250 MHz
NOTE:
1 . PE determines the level at which the outputs stop. When PE is LOW/HIGH, the nQ
is stopped in a HIGH/LOW state while the nQ is stopped at a LOW/HIGH state.
OUTPUT ENABLE/DISABLE
nsOE OMODE Output
L X Normal Operation
H L Tri-State
H H Gated(1)
NOTE:
1 . PE determines the level at which the outputs stop. When PE is LOW/HIGH, the nQ
and QFB are stopped in a HIGH/LOW state, while the nQ and QFB are stopped in a
LOW/HIGH state.
POWERDOWN
PD OMODE Output
H X Normal Operation
L L Tri-State
L H Gated(1)
NOTE:
1. The level to be set on FS is determined by the nominal operating frequency of the
VCO. The VCO frequency (FNOM) always appears at nQ and nQ outputs when they
are operated in their undivided modes. The frequency appearing at the REF[1:0] and
REF[1:0] /VREF[1:0] and FB and FB/VREF2 inputs will be FNOM when the QFB and QFB
are undivided and DS[1:0] = MM. The frequency of REF[1:0] and REF[1:0] /VREF[1:0]
and FB and FB/VREF2 inputs will be FNOM/2 or FNOM/4 when the part is configured for
frequency multiplication by using a divided QFB and QFB and setting DS[1:0] = MM.
Using the DS[1:0] inputs allows a different method for frequency multiplication (see
Divide Selection table).
NOTES:
1. Pins listed as LVTTL inputs will accept 2.5V signals under all conditions. If the output is operating at 1.8V or 1.5V, the LVTTL inputs will accept 1.8V LVTTL signals as well.
2. Outputs are user selectable to drive 2.5V, 1.8V LVTTL, eHSTL, or HSTL interface levels when used with the appropriate VDDQ voltage.
3. 3-level inputs are static inputs and must be tied to VDD or GND or left floating. These inputs are not hot-insertable or over voltage tolerant.