LINER LTC1598

Final Electrical Specifications
LTC1598
8-Channel, Micropower
Sampling 12-Bit Serial
I/O A/D Converter
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DESCRIPTION
FEATURES
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The LTC ®1598 is an 8-channel, 5V micropower, 12-bit
sampling A/D converter. It typically draws only 320µA
of supply current when converting and automatically
powers down to typically 1nA between conversions. The
LTC1598 is available in a 24-pin SSOP package and
operates on a 5V supply. The 12-bit, switched-capacitor,
successive approximation ADC includes an 8-channel
MUX and a sample-and-hold.
12-Bit Resolution
Auto Shutdown to 1nA
Low Supply Current: 320µA Typ
Guaranteed ±3/4LSB Max DNL
Single Supply 5V Operation
8-Channel Multiplexer
Separate MUX Output and ADC Input Pins
MUX and ADC May Be Controlled Separately
Sampling Rate: 16.8ksps
I/O Compatible with SPI, MICROWIRETM, etc.
24-Pin SSOP Package
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 consumption, makes remote location possible and facilitates transmitting data through isolation barriers.
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APPLICATIONS
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August 1996
Pen Screen Digitizing
Battery-Operated Systems
Remote Data Acquisition
Isolated Data Acquisition
Battery Monitoring
Temperature Measurement
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.
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TYPICAL APPLICATION
Supply Current vs Sample Rate
24µW, 8-Channel, 12-Bit ADC Samples at 200Hz and Runs Off a 5V Supply
1000
OPTIONAL
ADC FILTER
18
MUXOUT
ANALOG
INPUTS
0V TO 5V
RANGE
20
CH0
21
CH1
22
CH2
23
CH3
24
CH4
1
CH5
2
CH6
3
CH7
8
COM
5V
1µF
17
ADCIN
16
15, 19
VREF VCC
CS ADC
CS MUX
8-CHANNEL
MUX
+
12-BIT
SAMPLING
ADC
–
CLK
DIN
DOUT
NC
GND
4, 9
NC
1µF
10
6
SERIAL DATA LINK
MICROWIRE AND
SPI COMPATABLE
SUPPLY CURRENT (µA)
1k
TA = 25°C
VCC = 5V
VREF = 5V
fCLK = 320kHz
100
10
5, 14
7
11
12
MPU
1
0.1
13
1
10
SAMPLE FREQUENCY (kHz)
100
1598 TA02
LTC1598 • TA01
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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LTC1598
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ABSOLUTE MAXIMUM RATINGS
PACKAGE/ORDER INFORMATION
(Notes 1, 2)
Supply Voltage (VCC) to GND ................................... 12V
Voltage
Analog Reference .................... – 0.3V to (VCC + 0.3V)
Analog Inputs .......................... – 0.3V to (VCC + 0.3V)
Digital Inputs ......................................... – 0.3V to 12V
Digital Output .......................... – 0.3V to (VCC + 0.3V)
Power Dissipation.............................................. 500mW
Operating Temperature Range
LTC1598CG ............................................. 0°C to 70°C
LTC1598IG ........................................ – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
TOP VIEW
CH5
1
24 CH4
CH6
2
23 CH3
CH7
3
22 CH2
GND
4
21 CH1
CLK
5
20 CH0
CS MUX
6
19 VCC
DIN
7
18 MUX OUT
COM
8
17 ADC IN
GND
9
16 VREF
CS ADC 10
15 VCC
DOUT 11
14 CLK
NC 12
LTC1598CG
LTC1598IG
13 NC
G PACKAGE
24-LEAD PLASTIC SSOP
TJMAX = 150°C, θJA = 110°C/ W
Consult factory for Military grade parts.
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RECOM ENDED OPERATING CONDITIONS
PARAMETER
Supply Voltage (Note 3)
Clock Frequency
Total Cycle Time
Hold Time, DIN After CLK↑
Setup Time CS↓ Before First CLK↑ (See Operating Sequence)
Setup Time, DIN Stable Before CLK↑
CLK High Time
CLK Low Time
CS High Time Between Data Transfer Cycles
CS Low Time During Data Transfer
CONDITIONS
MIN
4.5
(Note 4)
60
150
1
400
1
1
16
44
VCC = 5V
fCLK = 320kHz
VCC = 5V
VCC = 5V
VCC = 5V
VCC = 5V
VCC = 5V
fCLK = 320kHz
fCLK = 320kHz
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SYMBOL
VCC
fCLK
tCYC
thDI
tsuCS
tsuDI
tWHCLK
tWLCLK
tWHCS
tWLCS
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CONVERTER AND MULTIPLEXER CHARACTERISTICS
PARAMETER
Resolution (No Missing Codes)
Integral Linearity Error
Differential Linearity Error
Offset Error
Gain Error
REF Input Range
Analog Input Range
MUX Channel Input Leakage Current
MUX OUT Leakage Current
ADC IN Input Leakage Current
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CONDITIONS
●
(Note 6)
●
●
●
●
(Notes 7, 8)
(Notes 7, 8)
Channel On or Off (Note 9)
All Channels Off
●
●
●
MIN
12
LTC1598CG
TYP
MAX
TYP
MAX
5.5
320
UNITS
V
kHz
µs
ns
µs
ns
µs
µs
µs
µs
(Note 5)
MIN
12
±3
± 3/4
±3
±8
1.5V to VCC + 0.05V
– 0.05V to VCC + 0.05V
±200
±200
±1
LTC1598IG
TYP
MAX
±3
±1
±3
±8
±200
±200
±1
UNITS
Bits
LSB
LSB
LSB
LSB
V
V
nA
nA
µA
LTC1598
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DYNAMIC ACCURACY
SYMBOL
S/(N + D)
THD
SFDR
(Note 5) fSMPL = 16.8kHz
PARAMETER
Signal-to-Noise Plus Distortion Ratio
Total Harmonic Distortion (Up to 5th Harmonic)
Spurious-Free Dynamic Range
Peak Harmonic or Spurious Noise
CONDITIONS
1kHz Input Signal
1kHz Input Signal
1kHz Input Signal
1kHz Input Signal
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DIGITAL AND DC ELECTRICAL CHARACTERISTICS
SYMBOL
VIH
VIL
IIH
IIL
VOH
PARAMETER
High Level Input Voltage
Low Level Input Voltage
High Level Input Current
Low Level Input Current
High Level Output Voltage
VOL
IOZ
ISOURCE
ISINK
RREF
Low Level Output Voltage
Hi-Z Output Leakage
Output Source Current
Output Sink Current
Reference Input Resistance
IREF
Reference Current
ICC
Supply Current
AC CHARACTERISTICS
CONDITIONS
VCC = 5.25V
VCC = 4.75V
VIN = VCC
VIN = 0V
VCC = 4.75V, IO = 10µA
VCC = 4.75V, IO = 360µA
VCC = 4.75V, IO = 1.6mA
CS = High
VOUT = 0V
VOUT = VCC
CS = VIH
CS = VIL
CS = VCC
tCYC ≥ 760µs, fCLK ≤ 25kHz
tCYC ≥ 60µs, fCLK ≤ 320kHz
CS = VCC, CLK = VCC, DIN = VCC
tCYC ≥ 760µs, fCLK ≤ 25kHz
tCYC ≥ 60µs, fCLK ≤ 320kHz
MIN
TYP
71
– 78
80
– 80
MAX
UNITS
dB
dB
dB
dB
MIN
2.6
TYP
MAX
UNITS
V
V
µA
µA
V
V
V
µA
mA
mA
MΩ
kΩ
µA
µA
µA
µA
µA
µA
(Note 5)
●
0.8
2.5
– 2.5
●
●
●
●
●
4.0
2.4
4.64
4.62
0.4
±3
●
●
– 25
45
5000
55
0.001
90
90
0.001
320
320
●
●
●
●
2.5
140
±5
640
(Note 5)
SYMBOL
tSMPL
fSMPL(MAX)
PARAMETER
Analog Input Sample Time
Maximum Sampling Frequency
CONDITIONS
See Operating Sequence 1
See Operating Sequence 1
tCONV
tdDO
tdis
ten
thDO
tf
tr
tON
tOFF
tOPEN
CIN
Conversion Time
Delay Time, CLK↓ to DOUT Data Valid
Delay Time, CS↑ to DOUT Hi-Z
Delay Time, CLK↓ to DOUT Enabled
Time Output Data Remains Valid After CLK↓
DOUT Fall Time
DOUT Rise Time
Enable Turn-On Time
Enable Turn-Off Time
Break-Before-Make Interval
Input Capacitance
See Operating Sequence 1
See Test Circuits
See Test Circuits
See Test Circuits
CLOAD = 100pF
See Test Circuits
See Test Circuits
See Operating Sequence 1
See Operating Sequence 2
MIN
●
MAX
16.8
●
●
●
●
●
●
●
●
Analog Inputs On-Channel
Off-Channel
Digital Input
TYP
1.5
35
12
250
135
75
230
50
50
260
100
160
20
5
5
600
300
200
150
150
700
300
UNITS
CLK Cycles
kHz
CLK Cycles
ns
ns
ns
ns
ns
ns
ns
ns
ns
pF
pF
pF
3
LTC1598
AC CHARACTERISTICS
The ● 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: This device is specified at 5V. Consult factory for 3V
specified devices.
Note 4: Increased leakage currents at elevated temperatures cause the S/H
to droop, therefore it is recommended that fCLK = 200kHz at 85°C,
fCLK ≥ 120kHz at 70°C and fCLK ≥ 1kHz at 25°C.
Note 5: VCC = 5V, VREF = 5V and CLK = 320kHz 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, it will therefore require a minimum supply voltage of
4.950V over initial tolerance, temperature variations and loading.
Note 8: Recommended operating condition.
Note 9: Channel leakage current is measured after the channel selection.
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PIN FUNCTIONS
CH5 (Pin 1): Analog Multiplexer Input.
CH6 (Pin 2): Analog Multiplexer Input.
DOUT (Pin 11): Digital Data Output. The A/D conversion
result is shifted out of this output.
CH7 (Pin 3): Analog Multiplexer Input.
NC (Pin 12): No Connection.
GND (Pin 4): Analog Ground. GND should be tied directly
to an analog ground plane.
NC (Pin 13): No Connection.
CLK (Pin 5): Shift Clock. This clock synchronizes the serial
data transfer to both MUX and ADC. It also determines the
conversion speed of the ADC.
VCC (Pin 15): Power Supply Voltage. This pin provides
power to the A/D Converter. It must be bypassed directly
to the analog ground plane.
CS MUX (Pin 6): MUX Chip Select Input. A logic high on
this input allows the MUX to receive a channel address. A
logic low enables the selected MUX channel and connects
it to the MUX OUT pin for A/D conversion. For normal
operation, drive this pin in parallel with CS ADC.
VREF (Pin 16): Reference Input. The reference input defines the span of the ADC.
DIN (Pin 7): Digital Data Input. The multiplexer address is
shifted into this input.
MUX OUT (Pin 18): MUX Output. This pin is the output of
the multiplexer. Tie to ADC IN for normal operation.
COM (Pin 8): Negative Analog Input. This input is the
negative analog input to the ADC and must be free of noise
with respect to GND.
VCC (Pin 19): Power Supply Voltage. This pin should be
tied to Pin 15.
GND (Pin 9): Analog Ground. GND should be tied directly
to an analog ground plane.
CS ADC (Pin 10): ADC Chip Select Input. A logic high on
this input deselects and powers down the ADC and threestates DOUT. A logic low on this input enables the ADC to
sample the selected channel and start the conversion. For
normal operation drive this pin in parallel with CS MUX.
4
CLK (Pin 14): Shift Clock. This input should be tied to Pin 5.
ADC IN (Pin 17): ADC Input. This input is the positive
analog input to the ADC. Connect this pin to MUX OUT for
normal operation.
CH0 (Pin 20): Analog Multiplexer Input.
CH1 (Pin 21): Analog Multiplexer Input.
CH2 (Pin 22): Analog Multiplexer Input.
CH3 (Pin 23): Analog Multiplexer Input.
CH4 (Pin 24): Analog Multiplexer Input.
LTC1598
TEST CIRCUITS
Load Circuit for tdDO, tr and tf
Voltage Waveforms for DOUT Rise and Fall Times, tr, tf
1.4V
VOH
DOUT
VOL
3k
DOUT
TEST POINT
tr
tf
1598 TC02
100pF
1598 TC01
Voltage Waveforms for ten
Voltage Waveforms for DOUT Delay Times, tdDO
LTC1598
CLK
CS ADC
VIL
tdDO
VOH
DOUT
1
CLK
2
VOL
1598 TC03
B11
DOUT
VOL
t en
Voltage Waveforms for tdis
Load Circuit for tdis and ten
VCC tdis WAVEFORM 2, ten
DOUT
100pF
VIH
CS
TEST POINT
3k
1598 TC06
DOUT
WAVEFORM 1
(SEE NOTE 1)
90%
tdis
tdis WAVEFORM 1
1598 TC04
DOUT
WAVEFORM 2
(SEE NOTE 2)
10%
NOTE 1: WAVEFORM 1 IS FOR AN OUTPUT WITH INTERNAL CONDITIONS SUCH
THAT THE OUTPUT IS HIGH UNLESS DISABLED BY THE OUTPUT CONTROL.
NOTE 2: WAVEFORM 2 IS FOR AN OUTPUT WITH INTERNAL CONDITIONS SUCH
THAT THE OUTPUT IS LOW UNLESS DISABLED BY THE OUTPUT CONTROL.
1598 TC05
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LTC1598
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APPLICATIONS INFORMATION
INPUT DATA WORD
ANALOG CONSIDERATIONS
The LTC1598 uses its Chip Select and DIN pins to select
one of its eight channels as shown in the operating
sequence figures and Table 1. For this discussion we will
assume that CS MUX and CS ADC are tied together and will
refer to them as simply, CS.
When CS is high, the input data on the DIN pin is latched
into the 4-bit shift register on the rising edge of the clock.
The input data word consists of an “EN” bit and a string of
three bits for channel selection. If the “EN” bit is logic high
as illustrated in Operating Sequence 1, it enables the
selected channel. To ensure correct operation, the CS
must be pulled low before the next rising edge of the clock.
More than four input bits can be sent to the ADC without
problems. The channel will be determined by the last four
bits clocked in before CS falls.
Once the CS is pulled low, all channels are simultaneously switched off to ensure a break-before-make
interval. After a delay of tON, the selected channel is
switched on, allowing signal transmission. The selected
channel remains on, until the next falling edge of CS. After
a delay of tOFF, it terminates the analog signal transmission and switches to the next selected channel. If the
“EN” bit is logic low, as illustrated in Operating Sequence
2, it disables all channels. Table 1 shows the various bit
combinations for channel selection.
Table 1. Logic Table for Channel Selection
CHANNEL STATUS
EN
D2
D1
DO
All Off
0
X
X
X
CH0
1
0
0
0
CH1
1
0
0
1
CH2
1
0
1
0
CH3
1
0
1
1
CH4
1
1
0
0
CH5
1
1
0
1
CH6
1
1
1
0
CH7
1
1
1
1
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Grounding
The LTC1598 should be used with an analog ground plane
and single-point grounding techniques. To achieve the
optimum performance use a printed circuit board. The
Ground pins (Pins 4 and 9) should be tied directly to the
ground plane with minimum lead length.
Bypassing
For good performance, the LTC1598 VCC and VREF pins
must be free of noise and ripple. Any changes in the VCC
and VREF voltages with respect to ground during the
conversion cycle can induce errors or noise in the output
code. Bypass the VCC and VREF pins directly to the analog
ground plane with minimum of 0.1µF capacitors and lead
lengths as short as possible.
Analog Inputs
Because of the capacitive redistribution A/D conversion
techniques used, the analog inputs of the LTC1598 have
capacitive switching input current spikes. These current
spikes settle quickly and do not cause a problem. But if
large source resistances are used, or if slow settling op
amps drive the inputs, take care to ensure the transients
caused by the current spikes settle completely before the
conversion begins.
LTC1598
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APPLICATIONS INFORMATION
Operating Sequence 1
Example: (CH2, GND)
tCYC
CS MUX = CS ADC = CS
tsuCS
CLK
EN
D1
DIN
DON’T CARE
D0
D2
NULL
BIT
HI-Z
DOUT
B11 B10 B9
B8
tSMPL
B7
B6
B5
B4
B3
B2
B1
B0
HI-Z
tCONV
CH0 TO
CH7
tON
ADC IN =
MUX OUT
COM = GND
1598 TD01
Operating Sequence 2
Example: (ALL Channels Off)
tCYC
CS MUX = CS ADC = CS
tsuCS
CLK
EN
D1
DIN
DON’T CARE
D0
D2
DOUT
NULL
BIT
HI-Z
DUMMY CONVERSION
HI-Z
tCONV
CH0 TO
CH7
tOFF
ADC IN =
MUX OUT
COM = GND
1598 TD02
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LTC1598
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TYPICAL APPLICATIONS
Microprocessor Interfaces
Motorola SPI (MC68HC05)
The LTC1598 can interface directly (without external hardware) to most popular microprocessors’ (MPU) synchronous serial formats including MICROWIRETM, SPI and
QSPI. If an MPU without a dedicated serial port is used,
then three of the MPU’s parallel port lines can be programmed to form the serial link to the LTC1598. Included
here is one serial interface example.
The MC68HC05 has been chosen as an example of an MPU
with a dedicated serial port. This MPU transfers data MSBfirst and in 8-bit increments. The DIN word sent to the data
register starts the SPI process. With three 8-bit transfers
the A/D result is read into the MPU. The second 8-bit
transfer clocks B11 through B7 of the A/D conversion
result into the processor. The third 8-bit transfer clocks
the remaining bits B6 through B0 into the MPU. ANDing
the second byte with 1FHEX clears the three most significant bits and ANDing the third byte with FEHEX clears the
least significant bit. Shifting the data to the right by one bit
results in a right justified word.
MICROWIRE is a trademark of National Semiconductor Corp.
LDA #$52
STA $0A
LDA #$FF
STA
STA
STA
LDA
$04
$05
$06
#$08
STA $50
START BSET 0,$02
LDA $50
STA $0C
LOOP1 TST $0B
BPL LOOP1
BCLR 0,$02
LDA $0C
STA $0C
LOOP2 TST $0B
BPL LOOP2
LDA $0C
STA $0C
AND #$IF
STA $00
LOOP3 TST $0B
BPL LOOP3
LDA $0C
AND #$FE
STA $01
JMP START
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MC68HC05 CODE
Configuration data for serial peripheral
control register (Interrupts disabled, output
enabled, master, Norm = 0, Ph = 0, Clk/16)
Load configuration data into location $0A (SPCR)
Configuration data for I/O ports
(all bits are set as outputs)
Load configuration data into Port A DDR ($04)
Load configuration data into Port B DDR ($05)
Load configuration data into Port C DDR ($06)
Put DIN word for LTC1598 into Accumulator
(CH0 with respect to GND)
Load DIN word into memory location $50
Bit 0 Port C ($02) goes high (CS goes high)
Load DIN word at $50 into Accumulator
Load DIN word into SPI data register ($0C) and
start clocking data
Test status of SPIF bit in SPI status register ($0B)
Loop if not done with transfer to previous
instruction
Bit 0 Port C ($02) goes low (CS goes low)
Load contents of SPI data register into Accumulator
Start next SPI cycle
Test status of SPIF
Loop if not done
Load contents of SPI data register into Accumulator
Start next SPI cycle
Clear 3 MSBs of first DOUT word
Load Port A ($00) with MSBs
Test status of SPIF
Loop if not done
Load contents of SPI data register into Accumulator
Clear LSB of second DOUT word
Load Port B ($01) with LSBs
Go back to start and repeat program
LTC1598
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TYPICAL APPLICATIONS
Data Exchange Between LTC1598 and MC68HC05
CS MUX
= CS ADC
= CS
CLK
D2
EN
DIN
D1
DON'T CARE
DO
DOUT
B11 B10
MPU
TRANSMIT
WORD
0
MPU
RECEIVED
WORD
?
0
0
0
EN
D2
D1
X
D0
X
X
?
?
X
B8
B7
X
X
X
B6
X
B5
B4
X
X
BYTE 2
BYTE 1
?
X
B9
?
?
?
?
?
?
0
B11 B10
B2
B1
B0
B1
X
X
X
X
X
B1
B0
B1
B2
BYTE 3
B9
B8
B7
B6
BYTE 2
BYTE 1
B3
B5
B4
B2
B3
BYTE 3
1598 TA03
Hardware and Software Interface to Motorola MC68HC05
DOUT FROM LTC1598 STORED IN MC68HC05 RAM
MSB
#00
0
0
0
B11
B10
B9
B8
B7
CS MUX
BYTE 1
CS ADC
ANALOG
INPUTS
LSB
#01
B6
B5
B4
B3
B2
B1
B0
0
BYTE 2
LTC1598
C0
MC68HC05
CLK
SCK
DIN
MOSI
DOUT
MISO
1598 TA04
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LTC1598
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TYPICAL APPLICATIONS
MULTICHANNEL A/D USES A SINGLE ANTIALIASING
FILTER
This circuit demonstrates how the LTC1598’s independent analog multiplexer can simplify design of a 12-bit
data acquisition system. All eight channels are MUXed into
a single 1kHz, fourth-order Sallen-Key antialiasing filter,
which is designed for single-supply operation. Since the
LTC1598’s data converter accepts inputs from ground to
the positive supply, rail-to-rail op amps were chosen for
the filter to maximize dynamic range. The LT1368 dual railto-rail op amp is designed to operate with 0.1µF load
capacitors (C1 and C2). These capacitors provide frequency compensation for the amplifiers and help reduce
the amplifier’s output impedance and improve supply
rejection at high frequencies. The filter contributes less
than 1LSB of error due to offsets and bias currents. The
filter’s noise and distortion are less than –72dB for a
100Hz, 2VP-P offset sine input.
The combined MUX and A/D errors result in an integral
nonlinearity error of ± 3LSB (maximum) and a differential
nonlinearity error of ±3/4LSB (maximum). The typical
signal-to-noise plus distortion ratio is 71dB, with approximately –78dB of total harmonic distortion. The LTC1598
is programmed through a 4-wire serial interface that is
compatable with MICROWIRE, SPI and QSPI. Maximum
serial clock speed is 320kHz, which corresponds to a
16.8kHz sampling rate.
The complete circuit consumes approximately 800µA
from a single 5V supply.
Simple Data Acquisition System Takes Advantage of the LTC1598’s
MUXOUT/ADCIN Pins-to-Filter Analog Signals Prior to A/D Conversion
ANALOG INPUTS
0V TO 5V
RANGE
5V
1
2
3
4
5
6
7
8
9
10
11
12
CH5
CH4
CH6
CH3
CH7
CH2
GND
CH1
CLK LTC1598 CH0
CS MUX
DIN
VCC
MUXOUT
COM
ADCIN
GND
VREF
CS ADC
VCC
DOUT
CLK
NC
NC
24
0.015µF
1µF
23
1/2
LT1368
21
20
7.5k
+
22
C2
0.1µF
5V
7.5k
0.03µF
–
19
18
1µF
17
7.5k
16
15
7.5k
0.015µF
14
0.03µF
13
+
1/2
LT1368
–
C1
0.1µF
DATA OUT
DATA IN
CHIP SELECT
CLOCK
10
LTC1598 • TA05
LTC1598
U
PACKAGE DESCRIPTION
Dimensions in inches (millimeters) unless otherwise noted.
G Package
24-Lead Plastic SSOP (0.209)
(LTC DWG # 05-08-1640)
0.318 – 0.328*
(8.07 – 8.33)
24 23 22 21 20 19 18 17 16 15 14 13
0.301 – 0.311
(7.65 – 7.90)
1 2 3 4 5 6 7 8 9 10 11 12
0.205 – 0.212**
(5.20 – 5.38)
0.068 – 0.078
(1.73 – 1.99)
0° – 8°
0.005 – 0.009
(0.13 – 0.22)
0.022 – 0.037
(0.55 – 0.95)
*DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSIONS DO NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
0.0256
(0.65)
BSC
0.010 – 0.015
(0.25 – 0.38)
0.002 – 0.008
(0.05 – 0.21)
G24 SSOP 0595
11
LTC1598
U
TYPICAL APPLICATION
Digitally Linearized Platinum RTD Signal Conditioner
5VOUT
+15V
LT1027
+
10µF
12k*
500k
400°C TRIM
12.5k*
+15V
+15V
+
A1
LT1101
A=10
–
1k*
Rplat.
+
1k
A2
LT1006
–
30.1k**
1µF
* TRW-IRC MAR-6 RESISTOR – 0.1%
** 1% FILM RESISTOR
Rplat. = 1kΩ AT 0°C – ROSEMOUNT #118MF
3.92M**
500k
ZERO°C TRIM
CH5
CH4
CH6
CH3
CH7
CH2
GND
CH1
CLK LTC1598 CH0
CS MUX
VCC
MUX OUT
DIN
COM
ADC IN
GND
VREF
VCC
CS ADC
CLK
DOUT
NC
NC
10µF
TANTALUM
TO/FROM
MC68HC05
LTC1598 TA06
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC1096/LTC1098
8-Pin SO, Micropower 8-Bit ADC
Low Power, Small Size, Low Cost
LTC1096L/LTC1098L
8-Pin SO, 2.65V Micropower 8-Bit ADC
Low Power, Small Size, Low Cost
LTC1196/LTC1198
8-Pin SO, 1Msps 8-Bit ADC
Low Power, Small Size, Low Cost
LTC1282
3V High Speed Parallel 12-Bit ADC
140ksps, Complete with VREF, CLK, Sample-and-Hold
LTC1285/LTC1288
8-Pin SO, 3V, Micropower
1- or 2-Channel, Auto Shutdown
LTC1289
Multiplexed 3V, 1A, 12-Bit ADC
8-Channel 12-Bit Serial I/O
LTC1594
4-Channel, 5V Micropower 12-Bit ADC
Low Power, Small Size, Low Cost
LTC1594L
4-Channel, 3V Micropower 12-Bit ADC
Low Power, Small Size, Low Cost
12
Linear Technology Corporation
LT/GP 0896 5K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● TELEX: 499-3977
 LINEAR TECHNOLOGY CORPORATION 1996