LM12454/LM12458/LM12H458
12-Bit + Sign Data Acquisition System with
Self-Calibration
General Description
The LM12454, LM12458, and LM12H458 are highly inte-
grated Data Acquisition Systems. Operating on just 5V, they
combine a fully-differential self-calibrating (correcting linear-
ity and zero errors) 13-bit (12-bit + sign) analog-to-digital
converter (ADC) and sample-and-hold (S/H) with extensive
analog functions and digital functionality. Up to 32 consecu-
tive conversions, using two's complement format, can be
stored in an internal 32-word (16-bit wide) FIFO data buffer.
An internal 8-word RAM can store the conversion sequence
for up to eight acquisitions through the LM12(H)458's
eight-input multiplexer. The LM12454 has a four-channel
multiplexer, a differential multiplexer output, and a differential
S/H input. The LM12454 and LM12(H)458 can also operate
with 8-bit + sign resolution and in a supervisory "watchdog"
mode that compares an input signal against two program-
mable limits.
Programmable acquisition times and conversion rates are
possible through the use of internal clock-driven timers. The
reference voltage input can be externally generated for ab-
solute or ratiometric operation or can be derived using the in-
ternal 2.5V bandgap reference.
All registers, RAM, and FIFO are directly addressable
through the high speed microprocessor interface to either an
8-bit or 16-bit databus. The LM12454 and LM12(H)458 in-
clude
a
direct
memory
access
(DMA)
interface
for
high-speed conversion data transfer.
An evaluation/interface board is available. Order num-
ber LM12458EVAL.
Additional applications information can be found in applica-
tions notes AN-906, AN-947 and AN-949.
Key Specifications
(f
CLK
= 5 MHz; 8 MHz, H)
j
Resolution
12-bit + sign or 8-bit + sign
j
13-bit conversion time
8.8 s, 5.5 s (H) (max)
j
9-bit conversion time
4.2 s, 2.6 s (H) (max)
j
13-bit Through-put rate
88k samples/s (min),
140k samples/s (H) (min)
j
Comparison time
("watchdog" mode)
2.2 s (max),
1.4 s (H) (max)
j
ILE
1 LSB (max)
j
V
IN
range
GND to V
A
+
j
Power dissipation
30 mW, 34 mW (H) (max)
j
Stand-by mode
50 W (typ)
j
Single supply
3V to 5.5V
Features
n
Three operating modes: 12-bit + sign, 8-bit + sign, and
"watchdog"
n
Single-ended or differential inputs
n
Built-in Sample-and-Hold and 2.5V bandgap reference
n
Instruction RAM and event sequencer
n
8-channel (LM12(H)458), 4-channel (LM12454)
multiplexer
n
32-word conversion FIFO
n
Programmable acquisition times and conversion rates
n
Self-calibration and diagnostic mode
n
8- or 16-bit wide databus dmicroprocessor or DSP
interface
Applications
n
Data Logging
n
Instrumentation
n
Process Control
n
Energy Management
n
Inertial Guidance
TRI-STATE
is a registered trademark of National Semiconductor Corporation.
AT
is a registered trademark of International Business Machines Corporation.
July 1999
LM12454/LM12458/LM12H458
12-Bit
+
Sign
Data
Acquisition
System
with
Self-Calibration
1999 National Semiconductor Corporation
DS011264
www.national.com
Ordering Information
Guaranteed
Guaranteed
Order
See NS
Clock Freq (min)
Linearity Error (max)
Part Number
Package Number
8 MHz
1.0 LSB
LM12H458CIV
V44A
LM12H458CIVF
VGZ44A
LM12H458MEL/883
EL44A
or 5962-9319502MYA
5 MHz
1.0 LSB
LM12454CIV
V44A
LM12458CIV
V44A
LM12458CIVF
VGZ44A
Connection Diagrams
DS011264-2
* Pin names in ( ) apply to the LM12454 and LM12H454.
Order Number LM12454CIV,
LM12458CIV or LM12H458CIV
See NS Package Number V44A
Order Number LM12H458MEL/883 or 5962-9319502MYA
See NS Package Number EL44A
DS011264-34
Order Number LM12458CIVF or LM12H458CIVF
See NS Package Number VGZ44A
www.national.com
2
Functional Diagrams
LM12454
DS011264-1
LM12(H)458
DS011264-21
www.national.com
3
Absolute Maximum Ratings
(Notes 1, 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
A
+ and V
D
+)
6.0V
Voltage at Input and Output Pins
except IN0IN3 (LM12454)
-0.3V to V
+
+ 0.3V
and IN0IN7 (LM12(H)458)
Voltage at Analog Inputs IN0IN3 (LM12454)
and IN0IN7 (LM12(H)458)
GND - 5V to V
+
+ 5V
|V
A
+ - V
D
+|
300 mV
Input Current at Any Pin (Note 3)
5 mA
Package Input Current (Note 3)
20 mA
Power Dissipation (T
A
= 25C)
V Package (Note 4)
875 mW
Storage Temperature
-65C to +150C
Lead Temperature
V Package, Infrared, 15 sec.
+300C
EL and W Packages,
Solder, 10 sec.
+250C
ESD Susceptibility (Note 5)
1.5 kV
LM12458MEL/883
2.0 kV
See AN-450 "Surface Mounting Methods and Their Effect on
Product Reliability" for other methods of soldering surface
mount devices.
Operating Ratings
(Notes 1, 2)
Temperature Range
(T
min
T
A
T
max
)
LM12454CIV/
LM12(H)458CIV
-40C
T
A
85C
LM12458MEL/883
-55C
T
A
125C
Supply Voltage
V
A
+, V
D
+
3.0V to 5.5V
|V
A
+ - V
D
+|
100 mV
V
IN+
Input Range
GND
V
IN+
V
A
+
V
IN-
Input Range
GND
V
IN-
V
A
+
V
REF+
Input Voltage
1V
V
REF+
V
A
+
V
REF-
Input Voltage
0V
V
REF-
V
REF+
- 1V
V
REF+
- V
REF-
1V
V
REF
V
A
+
V
REF
Common Mode
Range (Note 16)
0.1 V
A
+
V
REFCM
0.6 V
A
+
Converter Characteristics
(Notes 6, 7, 8, 9, 19)
The following specifications apply to the LM12454, LM12458, and LM12H458 for V
A
+ = V
D
+ = 5V, V
REF+
= 5V, V
REF-
= 0V,
12-bit + sign conversion mode, f
CLK
= 8.0 MHz (LM12H458) or f
CLK
= 5.0 MHz (LM12454/8), R
S
= 25
, source impedance for
V
REF+
and V
REF-
25
, fully-differential input with fixed 2.5V common-mode voltage, and minimum acquisition time unless
otherwise specified. Boldface limits apply for T
A
= T
J
= T
MIN
to T
MAX
; all other limits T
A
= T
J
= 25C.
Symbol
Parameter
Conditions
Typical
Limits
Unit
(Note 10)
(Note 11)
(Limit)
ILE
Positive and Negative Integral
After Auto-Cal (Notes 12, 17)
1/2
1
LSB (max)
Linearity Error
TUE
Total Unadjusted Error
After Auto-Cal (Note 12)
1
LSB
Resolution with No Missing Codes
After Auto-Cal (Note 12)
13
Bits (max)
DNL
Differential Non-Linearity
After Auto-Cal
3
/
4
LSB (max)
Zero Error
After Auto-Cal (Notes 13, 17)
1
LM12H458
1/2
1.5
LSB (max)
Positive Full-Scale Error
After Auto-Cal (Notes 12, 17)
1/2
2
LSB (max)
LM12(H)458MEL
2.5
Negative Full-Scale Error
After Auto-Cal (Notes 12, 17)
1/2
2
LSB (max)
LM12(H)458MEL
2.5
DC Common Mode Error
(Note 14)
2
3.5
LSB (max)
ILE
8-Bit + Sign and "Watchdog"
(Note 12)
Mode Positive and Negative
1/2
LSB (max)
Integral Linearity Error
TUE
8-Bit + Sign and "Watchdog" Mode
After Auto-Zero
1/2
3/4
LSB (max)
Total Unadjusted Error
8-Bit + Sign and "Watchdog" Mode
9
Bits (max)
Resolution with No Missing Codes
DNL
8-Bit + Sign and "Watchdog" Mode
3/4
LSB (max)
Differential Non-Linearity
8-Bit + Sign and "Watchdog" Mode
After Auto-Zero
1/2
LSB (max)
Zero Error
8-Bit + Sign and "Watchdog" Positive
1/2
LSB (max)
and Negative Full-Scale Error
www.national.com
4
Converter Characteristics
(Notes 6, 7, 8, 9, 19) (Continued)
The following specifications apply to the LM12454, LM12458, and LM12H458 for V
A
+ = V
D
+ = 5V, V
REF+
= 5V, V
REF-
= 0V,
12-bit + sign conversion mode, f
CLK
= 8.0 MHz (LM12H458) or f
CLK
= 5.0 MHz (LM12454/8), R
S
= 25
, source impedance for
V
REF+
and V
REF-
25
, fully-differential input with fixed 2.5V common-mode voltage, and minimum acquisition time unless
otherwise specified. Boldface limits apply for T
A
= T
J
= T
MIN
to T
MAX
; all other limits T
A
= T
J
= 25C.
Symbol
Parameter
Conditions
Typical
Limits
Unit
(Note 10)
(Note 11)
(Limit)
8-Bit + Sign and "Watchdog" Mode
1/8
LSB
DC Common Mode Error
Multiplexer Channel-to-Channel
0.05
LSB
Matching
V
IN+
Non-Inverting Input Range
GND
V (min)
V
A
+
V (max)
V
IN-
Inverting Input Range
GND
V (min)
V
A
+
V (max)
V
IN+
- V
IN-
Differential Input Voltage Range
-V
A
+
V (min)
V
A
+
V (max)
Common Mode Input Voltage Range
GND
V (min)
V
A
+
V (max)
PSS
Power Supply
Zero Error
V
A
+ = V
D
+ = 5V
10%
0.2
1.75
LSB (max)
Sensitivity
Full-Scale Error
V
REF+
= 4.5V, V
REF-
= GND
0.4
2
LSB (max)
(Note 15)
Linearity Error
0.2
LSB
C
REF
V
REF+
/V
REF-
Input Capacitance
85
pF
C
IN
Selected Multiplexer Channel Input
75
pF
Capacitance
Converter AC Characteristics
(Notes 6, 7, 8, 9, 19)
The following specifications apply to the LM12454, LM12458, and LM12H458 for V
A
+ = V
D
+ = 5V, V
REF+
= 5V, V
REF-
= 0V,
12-bit + sign conversion mode, f
CLK
= 8.0 MHz (LM12H458) or f
CLK
= 5.0 MHz (LM12454/8), R
S
= 25
, source impedance for
V
REF+
and V
REF-
25
, fully-differential input with fixed 2.5V common-mode voltage, and minimum acquisition time unless
otherwise specified. Boldface limits apply for T
A
= T
J
= T
MIN
to T
MAX
; all other limits T
A
= T
J
= 25C.
Symbol
Parameter
Conditions
Typical
Limits
Unit
(Note 10)
(Note 11)
(Limit)
Clock Duty Cycle
50
%
40
% (min)
60
%
(max)
t
C
Conversion Time
13-Bit Resolution,
44 (t
CLK
)
44 (t
CLK
) + 50 ns
(max)
Sequencer State S5 (
Figure 15)
9-Bit Resolution,
21 (t
CLK
)
21 (t
CLK
) + 50 ns
(max)
Sequencer State S5 (
Figure 15)
t
A
Acquisition Time
Sequencer State S7 (
Figure 15)
9 (t
CLK
)
9 (t
CLK
) + 50 ns
(max)
Built-in minimum for 13-Bits
Built-in minimum for 9-Bits and
2 (t
CLK
)
2 (t
CLK
) + 50 ns
(max)
"Watchdog" mode
t
Z
Auto-Zero Time
Sequencer State S2 (
Figure 15)
76 (t
CLK
)
76 (t
CLK
) + 50 ns
(max)
t
CAL
Full Calibration Time
Sequencer State S2 (
Figure 15)
4944 (t
CLK
)
4944 (t
CLK
) + 50 ns
(max)
Throughput Rate
89
88
kHz
(Note 18)
LM12H458
142
140
(min)
t
WD
"Watchdog" Mode Comparison
Sequencer States S6, S4,
11 (t
CLK
)
11 (t
CLK
) + 50 ns
(max)
Time
and S5 (
Figure 15)
www.national.com
5
PDF 
ZIP