Datasheet

4
LTC1091/LTC1092
LTC1093/LTC1094
AC CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are T
A
= 25°C. (Note 3)
LTC1091A/LTC1092A/LTC1093A/LTC1094A
LTC1091/LTC1092/LTC1093/LTC1094
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t
SMPL
Analog Input Sample Time See Operating Sequence 1.5 CLK Cycles
t
CONV
Conversion Time See Operating Sequence 10 CLK Cycles
t
dDO
Delay Time, CLK↓ to D
OUT
Data Valid See Test Circuits ● 400 850 ns
t
dis
Delay Time, CS↑ to D
OUT
Hi-Z See Test Circuits ● 180 450 ns
t
en
Delay Time, CLK↓ to D
OUT
Enabled See Test Circuits ● 160 450 ns
t
hDO
Time Output Data Remains Valid After SCLK↓ 150 ns
t
f
D
OUT
Fall Time See Test Circuits ● 90 300 ns
t
r
D
OUT
Rise Time See Test Circuits ● 60 300 ns
C
IN
Input Capacitance Analog Inputs On-Channel 65 pF
Analog Inputs Off-Channel 5 pF
Digital Inputs 5 pF
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are T
A
= 25°C. (Note 3)
E
LECTR
IC
AL C CHARA TER ST
ICS
DIGITAL
A
D
U
I
DC
LTC1091A/LTC1092A/LTC1093A/LTC1094A
LTC1091/LTC1092/LTC1093/LTC1094
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IH
High Level Input Voltage V
CC
= 5.25V ● 2.0 V
V
IL
Low Level Input Voltage V
CC
= 4.75V ● 0.8 V
I
IH
High Level Input Current V
IN
= V
CC
● 2.5 µA
I
IL
Low Level Input Current V
IN
= 0V ● –2.5 µA
V
OH
High Level Output Voltage V
CC
= 4.75V, I
OUT
= 10µA 4.7 V
V
CC
= 4.75V, I
OUT
= 360µA ● 2.4 4.0 V
V
OL
Low Level Output Voltage V
CC
= 4.75V, I
OUT
= 1.6mA ● 0.4 V
I
OZ
Hi-Z Output Leakage V
OUT
= V
CC
, CS High ● 3 µA
V
OUT
= 0V, CS High ● –3 µA
I
SOURCE
Output Source Current V
OUT
= 0V –10 mA
I
SINK
Output Sink Current V
OUT
= V
CC
10 mA
I
CC
Positive Supply Current LTC1091, CS High ● 1.5 3.5 mA
LTC1092/LTC1093/LTC1094, CS High, REF
+
Open ● 1.0 2.5 mA
I
REF
Reference Current LTC1092/LTC1093/LTC1094, V
REF
= 5V ● 0.5 1.0 mA
I
–
Negative Supply Current LTC1093/LTC1094, CS High, V
–
= –5V ● 150µA
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, AGND,
GND and REF
–
wired together (unless otherwise noted). REF
–
is internally
connected to the AGND pin on the LTC1093. DGND, AGND, REF
–
and V
–
are internally connected to the GND pin on the LTC1091/LTC1092.
Note 3: V
CC
= 5V, V
REF
+
= 5V, V
REF
–
= 0V, V
–
= 0V for unipolar mode and
–5V for bipolar mode, CLK = 0.5MHz unless otherwise specified.
Note 4: These specs apply for both unipolar (LTC1091/LTC1092/LTC1093/
LTC1094) and bipolar (LTC1093/LTC1094 only) modes. In bipolar mode,
one LSB is equal to the bipolar input span (2V
REF
) divided by 1024. For
example, when V
REF
= 5V, 1LSB (bipolar) = 2(5V)/1024 = 9.77mV.
Note 5: Linearity error is specified between the actual end points of the
A/D transfer curve.
Note 6: Total unadjusted error includes offset, full scale, linearity,
multiplexer and hold step errors.
Note 7: Two on-chip diodes are tied to each reference and analog input
which will conduct for reference or analog input voltages one diode drop
below V
–
or one diode drop above V
CC
. Be careful during testing at low
V
CC
levels (4.5V), as high level reference or analog inputs (5V) can cause
this input diode to conduct, especially at elevated temperatures, and cause
errors for inputs near full scale. This spec allows 50mV forward bias of
either diode. This means that as long as the reference or analog input does
not exceed the supply voltage by more than 50mV, the output code will be
correct. To achieve an absolute 0V to 5V input voltage range will therefore
require a minimum supply voltage of 4.950V over initial tolerance,
temperature variations and loading.
Note 8: Channel leakage current is measured after the channel selection.