|
|
PDF MLX90308CCC Data sheet ( Hoja de datos )
| Número de pieza | MLX90308CCC | |
| Descripción | Programmable Sensor Interface | |
| Fabricantes | Melexis Microelectronic | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de MLX90308CCC (archivo pdf) en la parte inferior de esta página. Total 26 Páginas | ||
|
No Preview Available !
MLX90308CCC
Programmable Sensor Interface
Features and Benefits
Microprocessor-controlled signal conditioning for bridge-type sensors
Suited for low-cost sensors: reduction of non-linearity by programmable coefficients
External or internal temperature sensor for compensating temperature errors
Versatile output signal ranges: 4, 5, 10, or 11VDC; 4 to 20 mA loop
Mass calibration easy with 2400 or 9600 baud UART
Power supply from 6 to 35VDC
Applications
Pressure transducers
Accelerometers
Temperature sensor assemblies
Linear position sensors
Ordering Information
art No.
Temperature Suffix
MLX90308CCC L
MLX90308CCC L
*UD denotes unpackaged die
Package
LW
UD*
Option
Temperature Range
-40C to 140C
-40C to 140C
Description
The MLX90308CCC is a dedicated microcontroller which performs signal conditioning for sensors wired in
bridge or differential configurations. Sensors that can be used include thermistors, strain gauges, load cells,
pressure sensors, accelerometers, etc. The signal conditioning includes gain adjustment, offset control, high
order temperature and linearity compensation. Compensation values are stored in EEPROM and are re-
programmable. Programming is accomplished by using a PC, with an interface circuit (level shifting and glue
logic), and provided software.
The application circuits can provide an
output of an absolute voltage, relative
voltage, or current. The output can be
range limited with defined outputs when
the signal is beyond the programmed
limits. Other features include alarm
outputs and level steering. The robust
electrical design allows the
MLX90308CCC to be used where most
signal conditioning and sensor interface
circuits cannot be used. Voltage
regulation control is provided for absolute
voltage and current modes (external FET
required).
The standard package is a plastic
SO16W. The device is static-sensitive and
requires ESD precautions.
MMLLXX99002x3x0N8CamCeCofPSroegnrsaomr mable Sensor Interface RePv aYg.Xe 1
22/ARuegv/928.2
23/Oct/P0a1ge 1
1 page  
MLX90308CCC
Programmable Sensor Interface
Table 1. MLX90308 Electrical Specifications (continued)
DC operating parameters: TA = -40 to 140oC, VDD1 = 6 to 35VDC (unless otherwise specified).
Parameter
Bandwidth (-3dB)
Test Conditions
Min Typ Max Units
39 nF connected from FLT to GND 2.8 3.5 4.2 KHz
Noise, VDD = 5V, CFLT=39nF, CL=10nF, RL =5KÙ, Analog Mode
5.0 mVRMS
Temperature Sensor & - Amplifier
Temperature sensor sensitivity
390 uV/ºC
Temperature sensor output voltage
70 380 mV
Temperature Sensor & Amplifier (continued).
Input voltage range TMP pin
GNTP[1,0] = 00
207 517 mV
@ VDD = 5.0V
GNTP[1,0] = 01
GNTP[1,0] = 10
145 367 mV
101 263 mV
GNTP[1,0] = 11
71 186 mV
DAC
Resolution
10 Bit
Monotonicity
Guaranteed By Design
Ratiometric output range (DAC output)
Offset Error
1 75 % VDD
10 LSB
Differential non-linearly
1 LSB
Integral non-linearity
2 LSB
ADC
Resolution
10 Bit
Monotonicity
Guaranteed by design
Ratiometric input range
Offset error
1 75 % VDD
10 LSB
Differential non-linearly
1 LSB
Integral non-linearity
2 LSB
On-Chip RC Oscillator and Clock
Untrimmed RC oscillator
frequency
Trimmed RC oscillator frequency
(Measured at TMP pin with TSTB pin pulled low after power up)
Frequency temperature coefficiency
40 250 kHz
86.9 87.8 88.7 kHz
26 Hz/ºC
Clock Stability with temperature compensation over full temperature range
-3
+3 %
Ratio of f (microcontroller main clock
and (RC oscillator)
TURBO = 0
TURBO = 1
7
28
MMLLXX99002x3x0N8CamCeCofPSroegnrsaomr mable Sensor Interface RePv aYg.Xe 5
22/ARuegv/928.2
23/Oct/P0a1ge 5
5 Page 
MLX90308CCC
Programmable Sensor Interface
Different Modes
Analog Mode
The parameters OF and GN represent, respectively,
offset correction and span control, while OFTCi and
GNTCi represent their temperature coefficients
(thermal zero shift and thermal span shift). After
reset, the firmware continuously calculates the
offset and gain DAC settings as follows: The
EEPROM holds parameters GN, OF, OFTCi and
GNTCi, where “i” is the gap number and can be 1 < i
< 4. The transfer function is described below.
Vout = FG * DAC_GAIN * CSGN[2:0] *
{Vin+DAC_OFFSET+CSOF}
Iout = FG * DAC_GAIN * CSGN[1:0] *
{Vin+DAC_OFFSET+CSOF} * 8.85mA/V
FG = Hardware Gain (~20V/V). Part of the hardware
design, and not changeable.
CSGN = Course Gain, part of byte 2 in EEPROM.
CSOF = Coarse Offset, part of byte 2 in
EEPROM.
GAIN
DAC_GAIN (new value) ~ GN[9:0] + [GNTCi * dT]
GN[9:0] = Fixed Gain, bytes 3 and 17 in EEPROM.
GNTCi = Gain TC for a given temperature
segment I. GNTCiL and GNTCiH in
EEPROM table.
dT = Temp. change within the appropriate gap.
How to calculate gain in the first temp. gap?:
DAC_GAIN = GN[9:0] - GNTC1 * (T1 – Temp_f1)
How to calculate gain in the other temp. gaps?:
2nd gap:DAC_GAIN = GN[9:0] + GNTC2 *
(Temp_f2 – T1)
3th gap: DAC_GAIN = DAC_GAIN2 + GNTC3 *
(Temp_f3 – T2)
4th gap: DAC_GAIN = DAC_GAIN3 + GNTC4 *
(Temp_f4 – T3)
Where:
Temp_f = Filtered temp. (previously described).
If GNTC1 > 2047
If GNTC2,3,4 > 2047
=> DAC_GAIN ↑
=> DAC_GAIN ↓
(0.97 − 0.48) * GN[9 : 0] + 0.48 = DAC _ GAIN [V/V]
1023
OFFSET
DAC_OFFSET (new value) ~ OF[9:0]+[OFTCi* dT]
OF[9:0] = Fixed Gain, bytes 4 and 17 in EEPROM.
OFTCi = Offset for a given temperature
segment I. OFTCiL and OFTCiH in
EEPROM table.
dT = Temp. change within the appropriate gap.
Calculation of the offset for a given temperature
segment is performed the same way as for the gain.
(7 − −6)* OF[9 : 0] − 6 = DAC _ OFFSET
1023
[mV/V]
Digital Mode
The MLX90308 firmware provides the capability of
digitally processing the sensor signal in addition to
the analog processing. This capability allows for
signal correction.
Signal Correction
While in digital mode the firmware can perform
signal correction. This is an adjustment to the
output level based on the input signal level.
Adjustment coefficients can be set for five different
signal ranges. The output is obtained by the
following formula:
Output = (Signal – Pi) * Pci + Poff where
Signal = input signal measurement;
Poff = Pressure ordinate
Pi = Pressure signal point (I = 2,3,4,5)
Pci = programmed coefficient.
The PCi coefficients are coded on 12 bits: one bit for
the sign, one for the unity, and the rest for the
decimals. The Pi are coded on 10 bits (0-3FFh) in
high-low order.
PNB_TNB: contains the number of signal points,
coded on the four MSB’s. The four LSB’s are
reserved for the number of temperature points. See
Table 4 and Table 5.
Compensation Trade-Offs
A compromise must be made between temperature
compensation and pressure correction. The
EEPROM space where the signal coefficients are
stored is shared with the temperature coefficients,
with the result that an EEPROM byte can be used
either for a temperature coefficient or for a signal
coefficient, but not both. Table 6 presents the
possibilities among the maximum number of
temperature gaps and the maximum number of
signal gaps.
MMLLXX99002x3x0N8CamCeCofPSroegnrsaomr mable Sensor Interface RePv aYg.Xe 11
22/ARuegv/928.2
23/Oct/P0a1ge 11
11 Page | ||
| Páginas | Total 26 Páginas | |
| PDF Descargar | [ Datasheet MLX90308CCC.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| MLX90308CCC | Programmable Sensor Interface | Melexis Microelectronic |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |