LTC1594L Datasheet, PDF (1/24 Pages) Linear Technology – 4- and 8-Channel, 3V Micropower Sampling 12-Bit Serial I/O A/D Converters

LTC1594L/LTC1598L
4- and 8-Channel,
3V Micropower Sampling
12-Bit Serial I/O A/D Converters
FEATURES
s _{12-Bit Resolution on 3V Supply}
s _{Low Supply Current: 160µA Typ}
s _{Auto Shutdown to 1nA}
s _{Guaranteed ±3/4LSB Max DNL}
s _{Guaranteed 2.7V Operation}
(5V Versions Available: LTC1594/LTC1598)
s _{Multiplexer: 4-Channel MUX (LTC1594L)}
8-Channel MUX (LTC1598L)
s _{Separate MUX Output and ADC Input Pins}
s _{MUX and ADC May Be Controlled Separately}
s _{Sampling Rate: 10.5ksps}
s _{I/O Compatible with QSPI, SPI and MICROWIRE}^TM_{, etc.}
s _{Small Package: 16-Pin Narrow SO (LTC1594L)}
2_U4-Pin SSOP (LTC1598L)
APPLICATIO S
s _{Pen Screen Digitizing}
s _{Battery-Operated Systems}
s _{Remote Data Acquisition}
s _{Isolated Data Acquisition}
s _{Battery Monitoring}
s _{Temperature Measurement}
DESCRIPTIO
The LTC^®1594L/LTC1598L are 3V micropower, 12-bit
sampling A/D converters that feature 4- and 8-channel
multiplexers, respectively. They typically draw only 160µA
of supply current when converting and automatically
power down to a typical supply current of 1nA between
conversions. The LTC1594L is available in a 16-pin SO
package and the LTC1598L is packaged in a 24-pin
SSOP. Both operate on a 3V supply. The 12-bit, switched-
capacitor, successive approximation ADCs include a
sample-and-hold.
On-chip serial ports allow efficient data transfer to a wide
range of microprocessors and microcontrollers over three
or four wires. This, coupled with micropower consump-
tion, makes remote location possible and facilitates trans-
mitting data through isolation barriers.
The circuit 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
MICROWIRE is a trademark of National Semiconductor Corporation.
TYPICAL APPLICATION
12µW, 8-Channel, 12-Bit ADC Samples at 200Hz and Runs Off a 3V Supply
OPTIONAL
ADC FILTER
1k
1µF
3V
ANALOG
INPUTS
0V TO 3V
RANGE
20 CH0
21 CH1
22 CH2
23 CH3
24 CH4
1 CH5
2 CH6
3 CH7
18
MUXOUT
8-CHANNEL
MUX
8 COM
17
ADCIN
16
15, 19
V_REF V_CC
12-BIT
+ SAMPLING
ADC
–
CSADC
CSMUX
CLK
D_IN
D_OUT
1µF
10
6
5, 14
7
11
SERIAL DATA LINK
MICROWIRE AND
SPI COMPATABLE
MPU
LTC1598L
GND
4, 9
12
NC
13
NC
1594L/98L TA01
Supply Current vs Sample Rate
1000
100
T_A = 25°C
V_CC = 2.7V
V_REF = 2.5V
f_CLK = 200kHz
10
1
0.1
1
10
100
SAMPLE FREQUENCY (kHz)
1594L/98L TA02
1