Datasheet
LTC2308
5
2308fb
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: All voltage values are with respect to ground with AV
DD
, DV
DD
and
OV
DD
wired together (unless otherwise noted).
Note 3: When these pin voltages are taken below ground or above V
DD
,
they will be clamped by internal diodes. These products can handle input
currents greater than 100mA below ground or above V
DD
without latchup.
Note 4: AV
DD
= 5V, DV
DD
= 5V, OV
DD
= 5V, f
SMPL
= 500kHz, internal
reference unless otherwise specifi ed.
Note 5: Linearity, offset and full-scale specifi cations apply for a single-
ended analog input with respect to COM.
Note 6: Integral nonlinearity is defi ned as the deviation of a code from a
straight line passing through the actual endpoints of the transfer curve.
The deviation is measured from the center of the quantization band.
TIMING CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating temperature
range, otherwise specifi cations are at T
A
= 25°C. (Note 4)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
f
SMPL(MAX)
Maximum Sampling Frequency
l
500 kHz
f
SCK
Shift Clock Frequency
l
40 MHz
t
WHCONV
CONVST High Time (Note 9)
l
20 ns
t
HD
Hold Time SDI After SCK↑
l
2.5 ns
t
SUDI
Setup Time SDI Valid Before SCK↑
l
0ns
t
WHCLK
SCK High Time f
SCK
= f
SCK(MAX)
l
10 ns
t
WLCLK
SCK Low Time f
SCK
= f
SCK(MAX)
l
10 ns
t
WLCONVST
CONVST Low Time During Data Transfer (Note 9)
l
410 ns
t
HCONVST
Hold Time CONVST Low After Last SCK↓ (Note 9)
l
20 ns
t
CONV
Conversion Time
l
1.3 1.6 μs
t
ACQ
Acquisition Time 7th SCK↑ to CONVST↑ (Note 9)
l
240 ns
t
REFWAKE
REFCOMP Wakeup Time (Note 12) C
REFCOMP
= 10μF, C
REF
= 2.2μF 200 ms
t
dDO
SDO Data Valid After SCK↓ C
L
= 25pF (Note 9)
l
10.8 12.5 ns
t
hDO
SDO Hold Time After SCK↓ C
L
= 25pF
l
4ns
t
en
SDO Valid After CONVST↓ C
L
= 25pF
l
11 15 ns
t
dis
Bus Relinquish Time C
L
= 25pF
l
11 15 ns
t
r
SDO Rise Time C
L
= 25pF 4 ns
t
f
SDO Fall Time C
L
= 25pF 4 ns
t
CYC
Total Cycle Time 2μs
Note 7: Bipolar zero error is the offset voltage measured from –0.5LSB
when the output code fl ickers between 0000 0000 0000 and 1111 1111
1111. Unipolar zero error is the offset voltage measured from +0.5LSB
when the output code fl ickers between 0000 0000 0000 and
0000 0000 0001.
Note 8: Full-scale bipolar error is the worst-case of –FS or +FS untrimmed
deviation from ideal fi rst and last code transitions and includes the effect
of offset error. Unipolar full-scale error is the deviation of the last code
transition from ideal and includes the effect of offset error.
Note 9: Guaranteed by design, not subject to test.
Note 10: All specifi cations in dB are referred to a full-scale ±2.048V input
with a 2.5V reference voltage.
Note 11: Full linear bandwidth is defi ned as the full-scale input frequency
at which the SINAD degrades to 60dB or 10 bits of accuracy.
Note 12: REFCOMP wakeup time is the time required for the REFCOMP pin
to settle within 0.5LSB at 12-bit resolution of its fi nal value after waking up
from SLEEP mode.