Direct Four-Wire Interface to Most MPU Serial Ports
and All MPU Parallel Ports
50kHz Maximum Throughput Rate
Available in 20-Lead PDIP and SO Wide Packages
The LTC
®
1290 is a data acquisition component which
contains a serial I/O successive approximation A/D con-
verter. It uses LTCMOS
TM
switched capacitor technology
to perform either 12-bit unipolar or 11-bit plus sign bipolar
A/D conversions. The 8-channel input multiplexer can be
configured for either single-ended or differential inputs (or
combinations thereof). An on-chip sample-and-hold is
included for all single-ended input channels. When the
LTC1290 is idle it can be powered down with a serial word
in applications where low power consumption is desired.
The serial I/O is designed to be compatible with industry
standard full duplex serial interfaces. It allows either MSB-
or LSB-first data and automatically provides 2's comple-
ment output coding in the bipolar mode. The output data
word can be programmed for a length of 8, 12 or 16 bits.
This allows easy interface to shift registers and a variety of
processors.
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTCMOS is a trademark of Linear Technology Corporation. All other trademarks
are the property of their respective owners. Protected by U.S. Patents, including 5287525.
KEY SPECIFICATIO S
■
■
■
Resolution: 12 Bits
Fast Conversion Time: 13µs Max Over Temp
Low Supply Current: 6.0mA
TYPICAL APPLICATIO
SINGLE-ENDED INPUT
0V TO 5V OR
±5V
±15V
OVERVOLTAGE RANGE*
1k
12-Bit 8-Channel Sampling Data Acquisition System
CH0
CH1
CH2
CH3
DIFFERENTIAL INPUT (+)
±5V
COMMON MODE RANGE (–)
•
•
•
V
CC
ACLK
SCLK
D
IN
LTC1290
D
OUT
CS
REF
+
REF
–
V
–
AGND
0.1µF
+
22µF
TANTALUM
1N5817
TO AND FROM
MICROPROCESSOR
CH4
CH5
•
•
•
CH6
CH7
COM
DGND
4.7µF
TANTALUM
–5V
1N5817
1290 • TA01
* FOR OVERVOLTAGE PROTECTION ON ONLY ONE CHANNEL LIMIT THE INPUT CURRENT TO 15mA. FOR OVERVOLTAGE PROTECTION
ON MORE THAN ONE CHANNEL LIMIT THE INPUT CURRENT TO 7mA PER CHANNEL AND 28mA FOR ALL CHANNELS. (SEE SECTION ON
OVERVOLTAGE PROTECTION IN THE APPLICATIONS INFORMATION SECTION.) CONVERSION RESULTS ARE NOT VALID WHEN THE SELECTED
OR ANY OTHER CHANNEL IS OVERVOLTAGED (V
IN
< V
–
OR V
IN
> V
CC
).
1290fe
U
5V
U
U
1N4148
+
LT
®
1027
8V TO 40V
1µF
1
LTC1290
ABSOLUTE
AXI U
RATI GS
(Notes 1, 2)
Operating Temperature Range
LTC1290BC, LTC1290CC, LTC1290DC .... 0°C to 70°C
LTC1290BI, LTC1290CI, LTC1290DI .... – 40°C to 85°C
LTC1290BM, LTC1290CM,
LTC1290DM
(OBSOLETE) ............
– 55°C to 125°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec.)................ 300°C
Supply Voltage (V
CC
) to GND or V
–
........................ 12V
Negative Supply Voltage (V
–
) .................... – 6V to GND
Voltage
Analog/Reference Inputs ......... (V
–
) – 0.3V to V
CC
+ 0.3V
Digital Inputs ........................................ – 0.3V to 12V
Digital Outputs ........................... – 0.3V to V
CC
+ 0.3V
Power Dissipation ............................................. 500mW
PACKAGE/ORDER I FOR ATIO
TOP VIEW
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
COM
1
2
3
4
5
6
7
8
9
20 V
CC
19 ACLK
18 SCLK
17 D
IN
16 D
OUT
15 CS
14
REF
+
13 REF
–
12 V
–
11 AGND
N PACKAGE
20-LEAD PDIP
DGND 10
T
JMAX
= 110°C,
θ
JA
= 100°C/W (N)
ORDER PART NUMBER
LTC1290BIN
LTC1290CIN
LTC1290DIN
LTC1290BCN
LTC1290CCN
LTC1290DCN
J PACKAGE
20-LEAD CERAMIC DIP
T
JMAX
= 150°C, q
JA
= 80°C/W (J)
N PART MARKING
LTC1290BMJ
LTC1290CMJ
LTC1290DMJ
LTC1290BIJ
LTC1290CIJ
LTC1290DIJ
OBSOLETE PACKAGE
Consider N Package for Alternate Source
Order Options
Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
*The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges.
1290fe
2
U
U
W
W W
U
W
TOP VIEW
CH0
1
CH1
2
CH2
3
CH3
4
CH4
5
CH5
6
CH6
7
CH7
8
COM
9
DGND
10
20
V
CC
19
ACLK
18
SCLK
17
D
IN
16
D
OUT
15
CS
14
REF
+
13
REF
–
12
V
–
11
AGND
SW PACKAGE
20-LEAD PLASTIC SO WIDE
T
JMAX
= 110°C,
θ
JA
= 130°C/W (SW)
ORDER PART NUMBER
LTC1290BCSW
LTC1290CCSW
LTC1290DCSW
LTC1290BISW
LTC1290CISW
LTC1290DISW
SW PART MARKING
LTC1290
CO VERTER A D
PARAMETER
Offset Error
Linearity Error (INL)
Gain Error
Minimum Resolution for Which
No Missing Codes are Guaranteed
Analog and REF Input Range
On Channel Leakage Current
(Note 8)
(Note 7)
On Channel = 5V
Off Channel = 0V
On Channel = 0V
Off Channel = 5V
Off Channel Leakage Current
(Note 8)
On Channel = 5V
Off Channel = 0V
On Channel = 0V
Off Channel = 5V
●
●
●
●
The
●
denotes the specifications
which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 3)
CONDITIONS
(Note 4)
(Notes 4, 5)
(Note 4)
●
●
●
●
W U
U
ULTIPLEXER CHARACTERISTICS
MIN
LTC1290B
TYP
MAX
±1.5
±0.5
±0.5
12
LTC1290C
MIN
TYP
MAX
±1.5
±0.5
±1.0
12
LTC1290D
MIN
TYP
MAX
±1.5
±0.75
±4.0
12
UNITS
LSB
LSB
LSB
Bits
V
µA
µA
µA
µA
(V
–
) – 0.05V to V
CC
+ 0.05V (V
–
) – 0.05V to V
CC
+ 0.05V (V
–
) – 0.05V to V
CC
+ 0.05V
±1
±1
±1
±1
±1
±1
±1
±1
±1
±1
±1
±1
1290fe
3
LTC1290
AC CHARACTERISTICS
SYMBOL
f
SCLK
f
ACLK
t
ACC
t
SMPL
t
CONV
t
CYC
t
dDO
PARAMETER
Shift Clock Frequency
A/D Clock Frequency
Delay Time from CS↓ to D
OUT
Data Valid
Analog Input Sample Time
Conversion Time
Total Cycle Time
Delay Time, SCLK↓ to D
OUT
Data Valid
The
●
denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C. (Note 3)
CONDITIONS
V
CC
= 5V (Note 6)
V
CC
= 5V (Note 6)
(Note 9)
See Operating Sequence
See Operating Sequence
See Operating Sequence (Note 6)
See Test Circuits LTC1290BC, LTC1290CC
●
LTC1290DC, LTC1290BI
LTC1290CI, LTC1290DI
LTC1290BM, LTC1290CM
●
LTC1290DM
(OBSOLETE)
t
dis
t
en
t
hCS
t
hDI
t
hDO
t
f
t
r
t
suDI
t
suCS
t
WHCS
C
IN
Delay Time, CS↑ to D
OUT
Hi-Z
Delay Time, 2nd ACLK↓ to D
OUT
Enabled
Hold Time, CS After Last SCLK↓
Hold Time, D
IN
After SCLK↑
Time Output Data Remains Valid After SCLK↓
D
OUT
Fall Time
D
OUT
Rise Time
Setup Time, D
IN
Stable Before SCLK↑
Setup Time, CS↓ Before Clocking in
First Address Bit
CS High Time During Conversion
Input Capacitance
See Test Circuits
See Test Circuits
V
CC
= 5V (Note 6)
(Notes 6, 9)
V
CC
= 5V (Note 6)
Analog Inputs On Channel
Analog Inputs Off Channel
Digital Inputs
●
●
LTC1290B/LTC1290C/LTC1290D
MIN
TYP
MAX
0
(Note 10)
2
7
52
12 SCLK +
56 ACLK
130
220
2.0
4.0
UNITS
MHz
MHz
ACLK
Cycles
SCLK
Cycles
ACLK
Cycles
Cycles
ns
180
270
ns
See Test Circuits
See Test Circuits
V
CC
= 5V (Note 6)
V
CC
= 5V (Note 6)
●
●
70
130
0
50
50
65
25
50
2 ACLK Cycles
+ 100ns
52
100
5
5
100
200
ns
ns
ns
ns
ns
130
50
ns
ns
ns
ACLK
Cycles
pF
pF
pF
1290fe
4
LTC1290
DIGITAL A D DC ELECTRICAL CHARACTERISTICS
SYMBOL
V
IH
V
IL
I
IH
I
IL
V
OH
V
OL
I
OZ
I
SOURCE
I
SINK
I
CC
PARAMETER
High Level Input Voltage
Low Level Input Voltage
High Level Input Current
Low Level Input Current
High Level Output Voltage
Low Level Output Voltage
High-Z Output Leakage
Output Source Current
Output Sink Current
Positive Supply Current
CONDITIONS
V
CC
= 5.25V
V
CC
= 4.75V
V
IN
= V
CC
V
IN
= 0V
V
CC
= 4.75V
V
CC
= 4.75V
I
O
= 10µA
I
O
= 360µA
I
O
= 1.6mA
●
●
●
●
●
●
●
●
The
●
denotes the specifications which
apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 3)
LTC1290B/LTC1290C/LTC1290D
MIN
TYP MAX
2.0
0.8
2.5
– 2.5
2.4
4.7
4.0
0.4
3
–3
–20
20
●
●
I
REF
I
–
Reference Current
Negative Supply Current
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 ground with DGND, AGND
