FEATURES
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LTC1286/LTC1298
Micropower Sampling
12-Bit A/D Converters In
S0-8 Packages
DESCRIPTION
The LTC1286/LTC1298 are micropower, 12-bit, succes-
sive approximation sampling A/D converters. They typi-
cally draw only 250碌A(chǔ) of supply current when converting
and automatically power down to a typical supply current
of 1nA whenever they are not performing conversions.
They are packaged in 8-pin SO packages and operate on
5V to 9V supplies. These 12-bit, switched-capacitor, suc-
cessive approximation ADCs include sample-and-holds.
The LTC1286 has a single differential analog input. The
LTC1298 offers a software selectable 2-channel MUX.
On-chip serial ports allow efficient data transfer to a wide
range of microprocessors and microcontrollers over three
wires. This, coupled with micropower consumption, makes
remote location possible and facilitates transmitting data
through isolation barriers.
These circuits can be used in ratiometric applications or
with an external reference. The high impedance analog
inputs and the ability to operate with reduced spans (to
1.5V full scale) allow direct connection to sensors and
transducers in many applications, eliminating the need for
gain stages.
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12-Bit Resolution
8-Pin SOIC Plastic Package
Low Cost
Low Supply Current: 250碌A(chǔ) Typ.
Auto Shutdown to 1nA Typ.
Guaranteed
鹵3/4LSB
Max DNL
Single Supply 5V to 9V Operation
On-Chip Sample-and-Hold
60碌s Conversion Time
Sampling Rates:
12.5 ksps (LTC1286)
11.1 ksps (LTC1298)
I/O Compatible with SPI, Microwire, etc.
Differential Inputs (LTC1286)
2-Channel MUX (LTC1298)
3V Versions Available: LTC1285/LTC1288
APPLICATIONS
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Battery-Operated Systems
Remote Data Acquisition
Battery Monitoring
Handheld Terminal Interface
Temperature Measurement
Isolated Data Acquisition
TYPICAL APPLICATIONS
N
25碌W, S0-8 Package, 12-Bit ADC
Samples at 200Hz and Runs Off a 5V Supply
4.7碌F
5V
Supply Current vs Sample Rate
1000
T
A
= 25擄C
V
CC
= V
REF
= 5V
f
CLK
= 200kHz
100
MPU
(e.g., 8051)
1
ANALOG INPUT
0V TO 5V RANGE
2
3
4
V
REF
+IN
鈥揑N
GND
V
CC
LTC1286 CLK
D
OUT
CS/SHDN
8
7
6
5
SERIAL DATA LINK
LTC1286/98 鈥?TA01
P1.4
P1.3
P1.2
SUPPLY CURRENT (碌A(chǔ))
10
1
0.1k
1k
10k
SAMPLE FREQUENCY (Hz)
100k
U
U
U
LTC1286/98 鈥?TA02
1