4
LTC1594/LTC1598
15948fb
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t
SMPL
Analog Input Sample Time See Figure 1 in Applications Information 1.5 CLK Cycles
f
SMPL(MAX)
Maximum Sampling Frequency See Figure 1 in Applications Information ● 16.8 kHz
t
CONV
Conversion Time See Figure 1 in Applications Information 12 CLK Cycles
t
dDO
Delay Time, CLK↓ to D
OUT
Data Valid See Test Circuits ● 250 600 ns
t
dis
Delay Time, CS↑ to D
OUT
Hi-Z See Test Circuits ● 135 300 ns
t
en
Delay Time, CLK↓ to D
OUT
Enabled See Test Circuits ● 75 200 ns
t
hDO
Time Output Data Remains Valid After CLK↓ C
LOAD
= 100pF 230 ns
t
f
D
OUT
Fall Time See Test Circuits ● 50 150 ns
t
r
D
OUT
Rise Time See Test Circuits ● 50 150 ns
t
ON
Enable Turn-On Time See Figure 1 in Applications Information ● 260 700 ns
t
OFF
Enable Turn-Off Time See Figure 2 in Applications Information ● 100 300 ns
t
OPEN
Break-Before-Make Interval ● 35 160 ns
C
IN
Input Capacitance Analog Inputs On-Channel 20 pF
Off-Channel 5 pF
Digital Input 5 pF
AC CHARACTERISTICS
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 GND.
Note 3: These devices are specified at 5V. Consult factory for 3V
specified devices (LTC1594L/LTC1598L).
Note 4: Increased leakage currents at elevated temperatures cause the S/H
to droop, therefore it is recommended that f
CLK
≥ 160kHz at 85°C,
f
CLK
≥ 75kHz at 70°C and f
CLK
≥ 1kHz at 25°C.
Note 5: V
CC
= 5V, V
REF
= 5V and CLK = 320kHz unless otherwise specified.
CSADC and CSMUX pins are tied together during the test.
Note 6: Linearity error is specified between the actual end points of the
A/D transfer curve.
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 GND or one diode drop above V
CC
. This spec allows 50mV forward
bias of either diode for 4.5V ≤ V
CC
≤ 5.5V. 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, it will therefore require a minimum supply voltage of
4.950V over initial tolerance, temperature variations and loading.
Note 8: Recommended operating condition. Not 100% production tested.
Note 9: Channel leakage current is measured after the channel selection.
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
SAMPLE FREQUENCY (kHz)
0.1
1
SUPPLY CURRENT (μA)
10
100
1000
1 10 100
1594/98 G01
T
A
= 25°C
V
CC
= 5V
V
REF
= 5V
f
CLK
= 320kHz
Supply Current vs Sample Rate
TEMPERATURE (°C)
–55
92.0
REFERENCE CURRENT (μA)
92.5
93.5
94.0
94.5
–15
25
45 125
1594/98 G03
93.0
–35 5
65
85
105
95.0
V
CC
= V
REF
= 5V
f
SMPL
= 16.8kHz
f
CLK
= 320kHz
TEMPERATURE (°C)
–55
200
SUPPLY CURRENT (μA)
250
350
400
450
–15
25
45 125
1594/98 G02
300
–35 5
65
85
105
T
A
= 25°C
V
CC
= V
REF
= 5V
f
CLK
= 320kHz
f
SMPL
= 16.8kHz
Supply Current vs Temperature
Reference Current vs Temperature
The ● denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C. (Note 5)
