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LINEAR TECHNOLOGY LTC1594 LTC1598 User Guide

Summary

These micropower, 12-bit A/D converters are designed for robust data acquisition in demanding environments. Featuring selectable 4- or 8-channel multiplexing and ultra-low operating currents (down to 1nA), they are ideal for battery-operated systems, remote monitoring, and portable instrumentation. The comprehensive manual details electrical specifications, serial I/O compatibility (SPI/QSPI/MICROWIRE), and application examples for engineers building high-precision, low-power sensor interfaces.

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LTC1594/LTC1598 4- and 8-Channel, Micropower Sampling

12-Bit Serial I/O A/D Converters

FEATURES DESCRIPTIO 12-Bit Resolution The LTC®1594/LTC1598 are micropower, 12-bit sampling Auto Shutdown to 1n A A/D converters that feature 4- and 8-channel multiplexers, Low Supply Current: 320µA Typ respectively. They typically draw only 320µA of supply

Guaranteed ±3/4LSB Max DNL current when converting and automatically power down to Single Supply 5V Operation a typical supply current of 1n A between conversions. The (3V Versions Available: LTC1594L/LTC1598L) LTC1594 is available in a 16-pin SO package and the Multiplexer: 4-Channel MUX (LTC1594) LTC1598 is packaged in a 24-pin SSOP. Both operate on 8-Channel MUX (LTC1598) a 5V supply. The 12-bit, switched-capacitor, successive Separate MUX Output and ADC Input Pins approximation ADCs include a sample-and-hold.

MUX and ADC May Be Controlled Separately

On-chip serial ports allow efficient data transfer to a wide

Sampling Rate: 16.8ksps

range of microprocessors and microcontrollers over three

I/O Compatible with QSPI, SPI and MICROWIRETM, etc.

or four wires. This, coupled with micropower consump-

Small Package: 16-Pin Narrow SO (LTC1594)

tion, makes remote location possible and facilitates trans-

24-Pin SSOP (LTC1598)

mitting data through isolation barriers.

APPLICATIO S The circuit can be used in ratiometric applications or with

SU PP LY UR RE NT (µ A)

an external reference. The high impedance analog inputs

Pen Screen Digitizing

and the ability to operate with reduced spans (to 1.5V full

Battery-Operated Systems

scale) allow direct connection to sensors and transducers

Remote Data Acquisition

in many applications, eliminating the need for gain stages.

Isolated Data Acquisition

, LTC and LT are registered trademarks of Linear Technology Corporation.

Battery Monitoring

MICROWIRE is a trademark of National Semiconductor Corporation.

Temperature Measurement

TYPICAL APPLICATIO 24µW, 4-Channel, 12-Bit ADC Samples at 200Hz and Runs Off a 5V Supply

OPTIONAL ADC FILTER

Supply Current vs Sample Rate

TA = 25°C VCC = 5V

1µF VREF = 5V

ADCINMUXOUT VREF VCC f CLK = 320k Hz

CH0 SERIAL DATA LINK

CH1 MICROWIRE AND

CSADC SPI COMPATABLE

CSMUX

ANALOG

CH3 12-BIT 5, 14 INPUTS 8-CHANNEL CLK

CH4 MUX SAMPLING MPU

0V TO 5V

ADC DIN

RANGE CH5

CH6 CH7

COM NC

GND 0.1

4, 9 1594/98 TA01 SAMPLE FREQUENCY (k Hz)

1594/98 TA02

15948fa

Page Summary Contents For LINEAR TECHNOLOGY LTC1594 LTC1598 User Guide

Page 1 LTC1594/LTC1598 4- and 8-Channel, Micropower Sampling 12-Bit Serial I/O A/D Converters FEATURES DESCRIPTIO 12-Bit Resolution The LTC®1594/LTC1598 are micropower, 12-bit sampling Auto Shutdown to 1n A ...
Page 2 LTC1594/LTC1598 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) Supply Voltage (VCC) to GND................................... 12V Power Dissipation 500m W Voltage Operating Temperature Range Analog Reference –...
Page 3 LTC1594/LTC1598 CONVERTER AND MULTIPLEXER CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Note 5) LT...
Page 4 SU PP LY UR RE NT (µ A) LTC1594/LTC1598 AC CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Note 5) S...
Page 5 EF FE CT IV NU BE OF IT (E NO Bs CH AN GE IN AI (L SB CH AN GE IN FF SE (L SB /4 EF LTC1594/LTC1598 TYPICAL PERFORMANCE CHARACTERISTICS Change in Offset Change in Linearity vs Reference Voltage Change...
Page 6 FE ED TH RO UG (d B) AT TE NU AT IO LTC1594/LTC1598 TYPICAL PERFORMANCE CHARACTERISTICS CL OC FR EQ UE NC (k Hz Attenuation vs Input Frequency 4096 Point FFT Plot Intermodulation Distortion TA = 25°C ...
Page 7 LTC1594/LTC1598 PIN FUNCTIONS LTC1594 CH0 (Pin 1): Analog Multiplexer Input. DOUT (Pin 10): Digital Data Output. The A/D conversion result is shifted out of this output. CH1 (Pin 2): Analog Multiplexe...
Page 8 LTC1594/LTC1598 PIN FUNCTIONS VCC (Pin 15): Power Supply Voltage. This pin provides VCC (Pin 19): Power Supply Voltage. This pin should be power to the A/D Converter. It must be bypassed directly tied...
Page 9 LTC1594/LTC1598 TEST CIRCUITS Voltage Waveforms for ten Voltage Waveforms for DOUT Delay Times, td DO LTC1594/LTC1598 CLK CSADC td DO 1594/98 TC03 1594/98 TC06 Load Circuit for tdis and ten Voltage Wa...
Page 10 LTC1594/LTC1598 APPLICATIONS INFORMATION OVERVIEW and can operate with reduced spans to 1.5V. Reducing the spans allow them to achieve 366µV resolution. The LTC1594/LTC1598 are micropower, 12-bit samp...
Page 11 LTC1594/LTC1598 APPLICATIONS INFORMATION t CYC CSMUX = CSADC = CS tsu CS EN D1 DIN D0N‘T CARE Hi-Z BIT Hi-ZDOUT DUMMY CONVERSION t CONV CH0 TO CH7 t OFF ADCIN = MUXOUT COM = GND Figure 2. LTC1594/LTC1...
Page 12 LTC1594/LTC1598 REF –1LSB APPLICATIONS INFORMATION REF –2LSB after a delay of t OFF, all the channels are switched off to Table 2. Logic Table for the LTC1598 Channel Selection ensure a break-before-m...
Page 13 LTC1594/LTC1598 APPLICATIONS INFORMATION Operation with DIN and DOUT Tied Together Therefore the processor port line must be switched to an input with CS being low to avoid a conflict. The LTC1594/LTC...
Page 14 LTC1594/LTC1598 APPLICATIONS INFORMATION CSADC CSMUX tsu CS tsu CS EN D1 EN D1 EN D1 DIN DON’T CARE DON’T CARE NULL NULL BIT BIT B4 B3 B2 B1 B0 B5B6B7B8B9B10B11DOUT B4 B3 B2 B1 B0 B5B6B7B8B9B10B11 B4 ...
Page 15 LTC1594/LTC1598 APPLICATIONS INFORMATION BOARD LAYOUT CONSIDERATIONS SAMPLE-AND-HOLD Both the LTC1594/LTC1598 provide a built-in sample- Grounding and Bypassing and-hold (S&H) function to acquire ...
Page 16 LTC1594/LTC1598 APPLICATIONS INFORMATION edge, the S & H goes into hold mode and the conversion During the conversion, the “analog” input voltage is begins. The voltage on the “COM” input must rem...
Page 17 LTC1594/LTC1598 APPLICATIONS INFORMATION Input Leakage Current Offset with Reduced VREF Input leakage currents can also create errors if the source The offset of the LTC1594/LTC1598 has a larger effec...
Page 18 LTC1594/LTC1598 AG NI TU DE (d B) APPLICATIONS INFORMATION Conversion Speed with Reduced VREF Effective Number of Bits With reduced reference voltages, the LSB step size is The Effective Number of Bit...
Page 19 LTC1594/LTC1598 APPLICATIONS INFORMATION specification in the Dynamic Accuracy table includes the For input frequencies of 5k Hz and 6k Hz, the IMD of the 2nd through 5th harmonics. With a 7k Hz input...
Page 20 LTC1594/LTC1598 TYPICAL APPLICATIONS N MC68HC05 CODE LDA #$52 Configuration data for serial peripheral BPL LOOP1 Loop if not done with transfer to previous instruction control register (Interrupts dis...
Page 21 LTC1594/LTC1598 TYPICAL APPLICATIONS N MULTICHANNEL A/D USES A SINGLE ANTIALIASING than 1LSB of error due to offsets and bias currents. The FILTER filter’s noise and distortion are less than –72d B fo...
Page 22 LTC1594/LTC1598 TYPICAL APPLICATIONS N Using MUXOUT/ADCIN Loop as PGA is the summation of the resistors below the selected MUX channel. If CH0 is selected, the loop gain is 1 since RS1 is This figure ...
Page 23 LTC1594/LTC1598 PACKAGE DESCRIPTION G Package 24-Lead Plastic SSOP (5.3mm) (Reference LTC DWG # 05-08-1640) 0.42 ±0.03 0.65 BSC RECOMMENDED SOLDER PAD LAYOUT BSC 0.05 NOTE: (.002) 1. CONTROLLING DIMEN...
Page 24 LTC1594/LTC1598 TYPICAL APPLICATION Using the LTC1598 and LTC1391 as an 8-Channel Differential 12-Bit ADC System ADCINMUXOUT VREF VCC CH0 CH1 CSADC CSMUX CH3 12-BIT 5, 14 8-CHANNEL 1µF CH4 MUX SAMPLIN...

Manual Details

Brand Linear
Pages 24
File Size 1018.23 KB
Published June 21, 2026
2 views

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Frequently Asked Questions

What is the maximum sampling rate?

The device offers a sampling rate up to 16.8ksps.

Does it support battery operation and data monitoring?

Yes, the product supports remote data acquisition and can be used for battery monitoring via MICROWIRE.

How many channels are available on each model?

The LTC1594 provides 4-channel multiplexing, while the LTC1598 offers 8-channel multiplexing.

What connection types does it support for data transfer?

It features on-chip serial ports compatible with QSPI, SPI, MICROWIRE, and three or four wires.