4
LTC1594L/LTC1598L
15948lfb
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 ● 10.5 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 ● 600 1500 ns
t
dis
Delay Time, CS↑ to D
OUT
Hi-Z See Test Circuits ● 220 600 ns
t
en
Delay Time, CLK↓ to D
OUT
Enabled See Test Circuits ● 180 500 ns
t
hDO
Time Output Data Remains Valid After CLK↓ C
LOAD
= 100pF 520 ns
t
f
D
OUT
Fall Time See Test Circuits ● 60 180 ns
t
r
D
OUT
Rise Time See Test Circuits ● 80 180 ns
t
ON
Enable Turn-On Time See Figure 1 in Applications Information ● 540 1200 ns
t
OFF
Enable Turn-Off Time See Figure 2 in Applications Information ● 190 500 ns
t
OPEN
Break-Before-Make Interval ● 125 350 ns
C
IN
Input Capacitance Analog Inputs On-Channel 20 pF
Off-Channel 5 pF
Digital Input 5 pF
AC CHARACTERISTICS
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 GND.
Note 3: These devices are specified at 3V. Consult factory for 5V
specified devices (LTC1594/LTC1598).
Note 4: Increased leakage currents at elevated temperatures cause the S/H
to droop, therefore it is recommended that f
CLK
≥ 200kHz at 85°C,
f
CLK
≥ 75kHz at 70°C and f
CLK
≥ 1kHz at 25°C.
Note 5: V
CC
= 2.7V, V
REF
= 2.5V and CLK = 200kHz 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 2.7V ≤ V
CC
≤ 3.6V. 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 3V
input voltage range, it will therefore require a minimum supply voltage of
2.950V over initial tolerance, temperature variations and loading.
Note 8: Recommended operating condition.
Note 9: Channel leakage current is measured after the channel selection.
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
Supply Current vs Sample Rate
Reference Current vs Temperature
Supply Current vs Temperature
SAMPLE FREQUENCY (kHz)
0.1
1
SUPPLY CURRENT (µA)
10
100
1000
1 10 100
1594L/98L G01
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
f
CLK
= 200kHz
TEMPERATURE (°C)
–55
60
SUPPLY CURRENT (µA)
100
180
220
260
–15
25
45 125
1594L/98L G02
140
–35 5
65
85
105
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
f
CLK
= 200kHz
f
SMPL
= 10.5kHz
TEMPERATURE (°C)
–55
43
REFERENCE CURRENT (µA)
44
46
47
48
53
50
–15
25
45 125
1594L/98L G03
45
51
52
49
–35 5
65
85
105
V
CC
= 2.7V
V
REF
= 2.5V
f
CLK
= 200kHz
f
SMPL
= 10.5kHz
The ● denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C.(Note 5)
