LTC1594 Datasheet, PDF (1/24 Pages) Linear Technology – 4- and 8-Channel, Micropower Sampling 12-Bit Serial I/O A/D Converters

LTC1594/LTC1598
4- and 8-Channel,
Micropower Sampling
12-Bit Serial I/O A/D Converters
FEATURES
■ _{12-Bit Resolution}
■ _{Auto Shutdown to 1nA}
■ _{Low Supply Current: 320μA Typ}
■ _{Guaranteed ±3/4LSB Max DNL}
■ _{Single Supply 5V Operation}
(3V Versions Available: LTC1594L/LTC1598L)
■ _{Multiplexer: 4-Channel MUX (LTC1594)}
8-Channel MUX (LTC1598)
■ _{Separate MUX Output and ADC Input Pins}
■ _{MUX and ADC May Be Controlled Separately}
■ _{Sampling Rate: 16.8ksps}
■ _{I/O Compatible with QSPI, SPI and MICROWIRE}^TM_{, etc.}
■ _{Small Package: 16-Pin Narrow SO (LTC1594)}
2_U4-Pin SSOP (LTC1598)
APPLICATIO S
■ _{Pen Screen Digitizing}
■ _{Battery-Operated Systems}
■ _{Remote Data Acquisition}
■ _{Isolated Data Acquisition}
■ _{Battery Monitoring}
■ _{Temperature Measurement}
DESCRIPTIO
The LTC^®1594/LTC1598 are micropower, 12-bit sampling
A/D converters that feature 4- and 8-channel multiplexers,
respectively. They typically draw only 320μA of supply
current when converting and automatically power down to
a typical supply current of 1nA between conversions. The
LTC1594 is available in a 16-pin SO package and the
LTC1598 is packaged in a 24-pin SSOP. Both operate on
a 5V 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.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
24μW, 4-Channel, 12-Bit ADC Samples at 200Hz and Runs Off a 5V Supply
OPTIONAL
ADC FILTER
1k
1μF
5V
ANALOG
INPUTS
0V TO 5V
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
GND
4, 9
12
NC
13
NC
1594/98 TA01
Supply Current vs Sample Rate
1000
100
T_A = 25°C
V_CC = 5V
V_REF = 5V
f_CLK = 320kHz
10
1
0.1
1
10
100
SAMPLE FREQUENCY (kHz)
1594/98 TA02
15948fb
1