LTC1286C View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC1286C' PDF : 24 Pages View PDF
LTC1286/LTC1298
AC CHARACTERISTICS (Note 5)
SYMBOL PARAMETER
tSMPL
Analog Input Sample Time
fSMPL(MAX) Maximum Sampling Frequency
tCONV
tdDO
tdis
ten
thDO
tf
tr
CIN
Conversion Time
Delay Time, CLK↓ to DOUT Data Valid
Delay Time, CS↑ to DOUT Hi-Z
Delay Time, CLK↓ to DOUT Enable
Time Output Data Remains Valid After CLK↓
DOUT Fall Time
DOUT Rise Time
Input Capacitance
CONDITIONS
See Operating Sequence
LTC1286
LTC1298
See Operating Sequence
See Test Circuits
See Test Circuits
See Test Circuits
CLOAD = 100pF
See Test Circuits
See Test Circuits
Analog Inputs, On Channel
Analog Inputs, Off Channel
Digital Input
MIN TYP MAX
UNITS
1.5
CLK Cycles
q 12.5
kHz
q 11.1
kHz
12
CLK Cycles
q
250 600
ns
q
135 300
ns
q
75 200
ns
230
ns
q
20 75
ns
q
20 75
ns
20
pF
5
pF
5
pF
The q denotes specifications which apply over the full operating
temperature range.
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 5V. For 3V specified devices, see
LTC1285 and LTC1288.
Note 4: Increased leakage currents at elevated temperatures cause the S/H
to droop, therefore it is recommended that fCLK ≥ 120kHz at 85°C, fCLK ≥
75kHz at 70° and fCLK ≥ 1kHz at 25°C.
Note 5: VCC = 5V, VREF = 5V and CLK = 200kHz unless otherwise specified.
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 VCC. This spec allows 50mV forward
bias of either diode for 4.5V ≤ VCC ≤ 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 will therefore require a minimum supply voltage of
4.950V over initial tolerance, temperature variations and loading. For 5.5V
< VCC ≤ 9V, reference and analog input range cannot exceed 5.55V. If
reference and analog input range are greater than 5.55V, the output code
will not be guaranteed to be correct.
Note 8: The supply voltage range for the LTC1286 is from 4.5V to 9V, but
the supply voltage range for the LTC1298 is only from 4.5V to 5.5V.
Note 9: Recommended operating conditions
Note 10: Channel leakage current is measured after the channel selection.
TYPICAL PERFORMANCE CHARACTERISTICS
Supply Current vs Sample Rate
1000
TA = 25°C
VCC = VREF = 5V
fCLK = 200kHz
100
LTC1298
LTC1286
10
1
0.1k
1k
10k
SAMPLE RATE (kHz)
100k
LT1286/98 G03
Supply Current vs Temperature
450
TA = 25°C
400
VCC = VREF = 5V
fCLK = 200kHz
350
LTC1298 fSMPL =11.1kHz
300
250
LTC1286 fSMPL =12.5kHz
200
–55 –35 –15 5 25 45 65 85 105 125
TEMPERATURE (°C)
LT1286/98 G04
Shutdown Supply Current vs Clock
Rate with CS High and CS Low
35
TA = 25°C
30 VCC = VREF = 5V
25
20
15
10
CS = 0
(AFTER CONVERSION)
5
1
0.002
CS = VCC
0
1 20 40 60 80 100 120 140 160 180 200
FREQUENCY (kHz)
LT1286/98 G01
4
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