
7
IN
DEVELOPMENT
3.0 PIN DESCRIPTION
Flatpack
Pin No.
Name
I/O
Type
Description
37
XTAL1
I
LVTTL
Primary reference clock input. When interfacing a single-ended reference clock
to the UT7R995 or UT7R995C, this input must be driven by an LVTTL/LVCMOS
clock source.
If a quartz crystal is used as the reference clock source (UT7R995C only), the second
pin on the crystal must be connected to XTAL2. If a singled ended reference clock
is supplied to this pin, then XTAL2 should be left unconnected.
36
N/C
--
No Connect. UT7R995 Only.
XTAL2
O
N/A
Feedback output from the on-board crystal oscillator. When a crystal is used to
supply the reference clock for the UT7R995C, this pin must be connected to the
second terminal of the quartz crystal. If a single-ended reference clock is supplied
to XTAL1, then this output should be left unconnected.
13
FB
I
LVTTL
Feedback input for the PLL. When FB is not driven by an active clock output the
PLL will run to its maximum frequency, unless the device is placed in power-down.
28
TEST 1
I
3-Level
Built-in test control signal. When Test is set to the MID or HIGH level, it disables
the PLL and the XTAL1 reference frequency is driven to all outputs (except for the
conditions described in note 2). Set Test LOW for normal operation.
2.0 RADIATION HARDNESS
Notes:
1. The UT7R995/C are latchup immune to particle LETs >109 MeV-cm2/mg.
2. Worst case temperature and voltage of TC = +125
oC, V
DD = 3.6V,
VDDQ1/Q3/Q4 = 3.6V for SEL.
3. Worst case temperature and voltage of TC = +25
oC, V
DD = 3.0V,
VDDQ1/Q3/Q4 = 3.0V for SEU.
4. Adams 90% worst case particle environment, Geosynchronous orbit,
100mils of Aluminum shielding.
Notes:
1. This SEU data is based on a test chip containing an array of 256 registers that
are identical to the 30 registers used within the UT7R995/C.
2. All SEU data specified in this datasheet is based on the storage elements used
in the UT7R995/C. Please contact the factory for details regarding SET per-
formance of the UT7R995/C.
Table 13: Radiation Hardness Design Specifications
Parameter
Limit
Units
Total Ionizing Dose (TID)
>1E6
rads(Si)
Single Event Latchup (SEL) 1, 2
>109
MeV-cm2/mg
SEU Saturated Cross-Section (
σ
sat)
1.0E-8
cm2/device
Onset Single Event Upset (SEU) LET
Threshold 3
109
MeV-cm2/mg
Neutron Fluence
1.0E14
n/cm2
Dose Rate Upset
TBD
rads(Si)/sec
Dose Rate Survivability
TBD
rads(Si)/sec
Table 14: Weibull and Device Parameters (256 Registers1)
Parameter
Limit
Units
Shape Parameter
TBD
--
Width Parameter
TBD
--
Structural Cross-Section (
σ)1.0E-8
cm2/device
Onset SEU LET2
109
MeV-cm2/mg
Depletion Depth
TBD
m
Funnel Depth
TBD
m