MAX1455
Download correction coefficients to EEPROM.
Perform a final test.
Sensor Calibration and
Compensation Example
The MAX1455 temperature compensation design cor-
rects both sensor and IC temperature errors. This
enables the MAX1455 to provide temperature compen-
sation approaching the inherent repeatability of the
sensor. An example of the MAX1455s capabilities is
shown in Figure 8. Table 16 lists the effects of compen-
sation.
A MAX1455 and a repeatable piezoresistive sensor with
an initial offset of 16.4mV and a span of 55.8mV were
converted into a compensated transducer with an offset
of 0.5000V and a span of 4.0000V. Nonlinear sensor
offset and FSO temperature errors, which were on the
order of 20% to 30% FSO, were reduced to under
±0.1% FSO. Figure 8 shows the output of the uncom-
pensated sensor and the output of the compensated
transducer. Six temperature points were used to obtain
this result.
MAX1455 Evaluation Kit
To expedite the development of MAX1455-based
transducers and test systems, Maxim has produced the
MAX1455 evaluation kit (EV kit). First-time users of the
MAX1455 are strongly encouraged to use this kit.
The EV kit is designed to facilitate manual programming
of the MAX1455 with a sensor. It includes the following:
1) Evaluation board with or without a silicon pressure
sensor, ready for customer evaluation.
2) Design/applications manual. This manual was
developed for test engineers familiar with data
acquisition of sensor data and provides sensor
compensation algorithms and test procedures.
3) MAX1455 communication software, which enables
programming of the MAX1455 from a computer key-
board (IBM compatible), one module at a time.
4) Interface adapter, which allows the connection of
the evaluation board to a PC serial port.
Chip Information
TRANSISTOR COUNT: 62,242
PROCESS: CMOS
SUBSTRATE CONNECTED TO: V
SS
Low-Cost Automotive Sensor Signal
Conditioner
22 ______________________________________________________________________________________
80
60
0
20
40
04020 60 80 100
RAW SENSOR OUTPUT
(T
A
= +25°C)
PRESSURE (kps)
V
OUT
(mV)
0
1
3
2
4
5
04020 60 80 100
COMPENSATED TRANSDUCER
(T
A
= +25°C)
PRESSURE (kps)
V
OUT
(V)
-20
10
30
20
-10
0
UNCOMPENSATED SENSOR
TEMPERATURE ERROR
TEMPERATURE (°C)
ERROR (% FSO)
-50 500 100 150
FSO OFFSET
-0.15
-0.05
-0.10
0.05
0
0.10
0.15
-50 500
100
150
COMPENSATED TRANSDUCER ERROR
TEMPERATURE (°C)
ERROR (% FSO)
FSO OFFSET
Figure 8. Comparison of an Uncalibrated Sensor and a Calibrated Transducer
MAX1455
Low-Cost Automotive Sensor Signal
Conditioner
______________________________________________________________________________________ 23
V
DD
V
DD
V
SS
V
SS
EEPROM
(LOOKUP PLUS CONFIGURATION DATA)
V
DD
V
SS
V
DD
V
SS
FSO
DAC
UNLOCK
V
DD1
16 BIT
16 BIT
8-BIT
LOOKUP
ADDRESS
BANDGAP
TEMP
SENSOR
PGA MUXMUX
FSOTC REGISTER
R
STC
75k
R
ISRC
75k
BDR
INP
INM
FSOTC
DAC
V
SS
EEPROM ADDRESS
15EH + 15FH
000H + 001H
:
OFFSET DAC LOOKUP TABLE
(176
16 BITS)
CONFIGURATION REGISTER SHADOW
USAGE
19EH + 19FH
16CH + 16DH
:
USER STORAGE (52 BYTES)
2FEH + 2FFH
1A0H + 1A1H
:
FSO DAC LOOKUP TABLE
(176
16 BITS)
160H + 161H
RESERVED162H + 163H
OFFSET TC REGISTER SHADOW164H + 165H
RESERVED166H + 167H
FSOTC REGISTER SHADOW168H + 169H
CONTROL LOCATION REGISTER16AH + 16BH
OFFSET
DAC
±1
±1
24
PHASE
REVERSAL
MUX
OUT
AMP-
AMPOUT
AMP+
PGA GAIN
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
9.0
8.5
PGA (3:0)
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1111
1110
TOTAL GAIN
39
52
65
78
91
104
117
130
143
156
169
182
195
208
234
221
IRO (3, 2:0) OFFSET (mV)
63
54
45
36
27
18
9
0
0
-9
-18
-27
-36
-45
-63
-54
1,111
1,110
1,101
1,100
1,011
1,010
1,001
1,000
0,000
0,001
0,010
0,011
0,100
0,101
0,111
0,110
V
SS
16 BIT
OFFSET
TC DAC
OTC REGISTER
INPUT-REFERRED OFFSET
(COARSE OFFSET) PROGRAMMABLE GAIN STAGE
UNCOMMITTED OP AMP
VALUE
V
SS
TO V
DD
±20mV
V
SS
, V
DD
±0.01V
V
SS
, V
DD
±0.25V
10MHz TYPICAL
PARAMETER
I/P RANGE
I/P OFFSET
O/P RANGE
NO LOAD
1mA LOAD
UNITY GBW
PGA BANDWIDTH 3kHz ±10%
16 BIT
*INPUT-REFERRED
OFFSET VALUE IS
PROPORTIONAL TO V
DD
.
VALUES GIVEN ARE FOR
V
DD
= +5V.
V
SS
PGA BANDWIDTH
3kHz ±10%
V
SS
V
DD2
DIO
DIGITAL
INTERFACE
TEST 1
TEST 2
TEST 3
TEST 4
CLIP-HIGH
DAC
CLIP-LOW
DAC
Detailed Functional Diagram
MAX1455
Low-Cost Automotive Sensor Signal
Conditioner
Package Information
SSOP.EPS
24 ______________________________________________________________________________________

MAX1455EVKIT-NS

Mfr. #:
Manufacturer:
Maxim Integrated
Description:
Temperature Sensor Development Tools Eval Kit MAX1455 (Low-Cost Automotive Sensor Signal Conditioner)
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet