LTC1857/LTC1858/LTC1859
W U
TI I G CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. (Note 5)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
f
Maximum Sampling Frequency
Through CH0 to CH7 Inputs
Through ADC , ADC Only
●
100
kHz
kHz
SAMPLE(MAX)
+
–
166
4
t
t
Conversion Time
Acquisition Time
●
●
5
4
µs
CONV
ACQ
Through CH0 to CH7 Inputs
µs
µs
+
–
Through ADC , ADC Only
(Note 14)
1
f
t
t
t
t
t
t
t
t
t
SCK Frequency
SDO Rise Time
SDO Fall Time
●
0
20
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
SCK
r
See Test Circuits
See Test Circuits
6
6
f
CONVST High Time
CONVST to BUSY Delay
SCK Period
●
●
●
●
●
●
●
40
1
C = 25pF, See Test Circuits
L
15
30
2
50
10
10
3
SCK High
4
SCK Low
5
Delay Time, SCK↓to SDO Valid
C = 25pF, See Test Circuits
L
25
20
45
30
6
Time from Previous SDO Data Remains C = 25pF, See Test Circuits
Valid After SCK↓
5
7
L
t
t
t
t
t
t
SDO Valid After RD↓
C = 25pF, See Test Circuits
L
●
●
●
●
●
●
11
ns
ns
ns
ns
ns
ns
8
RD↓ to SCK Setup Time
SDI Setup Time Before SCK↑
SDI Hold Time After SCK↑
SDO Valid Before BUSY↑
Bus Relinquish Time
20
0
9
10
11
12
13
7
RD = Low, C = 25pF, See Test Circuits
5
20
10
L
See Test Circuits
30
Note 1: Absolute maximum ratings are those values beyond which the life
of a device may be impaired.
Note 2: All voltage values are with respect to ground with DGND, AGND1,
AGND2 and AGND3 wired together unless otherwise noted.
Note 8: Bipolar zero error is the offset voltage measured from –0.5LSB
when the output code flickers between 0000 0000 0000 0000 and 1111
1111 1111 1111 for the LTC1859, between 00 0000 0000 0000 and 11
1111 1111 1111 for the LTC1858 and between 0000 0000 0000 and 1111
1111 1111 for the LTC1857. Unipolar zero error is the offset voltage
measured from 0.5LSB when the output codes flicker between 0000 0000
0000 0000 and 0000 0000 0000 0001 for the LTC1859, between 00 0000
0000 0000 and 00 0000 0000 0001 for the LTC1858 and between 0000
0000 0000 and 0000 0000 0001 for the LTC1857.
Note 3: When these pin voltages are taken below ground or above AV
=
DD
DV = OV = V , they will be clamped by internal diodes. This product
DD
DD
DD
can handle currents of greater than 100mA below ground or above V
DD
without latchup.
Note 4: When these pin voltages are taken below ground they will be
clamped by internal diodes. This product can handle currents of greater
than 100mA below ground without latchup. These pins are not clamped
Note 9: Guaranteed by design, not subject to test.
Note 10: Recommended operating conditions.
to V
.
Note 11: Full-scale bipolar error is the worst case of –FS or +FS
untrimmed deviation from ideal first and last code transitions, divided by
the full-scale range, and includes the effect of offset error. For unipolar
full-scale error, the deviation of the last code transition from ideal, divided
by the full-scale range, and includes the effect of offset error.
DD
Note 5: V = 5V, f
specified.
Note 6: Linearity, offset and full-scale specifications apply for a single-
ended analog MUX input with respect to ground or ADC with respect to
= 100kHz, t = t = 5ns unless otherwise
r f
DD
SAMPLE
+
–
Note 12: All Specifications in dB are referred to a full-scale ±10V input.
ADC tied to ground.
Note 13: Recovers to specified performance after (2 • FS) input
overvoltage.
Note 7: Integral nonlinearity is defined as the deviation of a code from a
straight line passing through the actual end points of the transfer curve.
The deviation is measured from the center of the quantization band.
Note 14: t of 45ns maximum allows f
up to 10MHz for rising capture
6
SCK
with 50% duty cycle and f
up to 20MHz for falling capture (with 5ns
SCK
setup time for the receiving logic).
Note 15: The specification is referred to the ±10V input range.
185789f
5
Linear Systems [ Linear Systems ]
