Motorola MPX7100ASX, MPX7100A, MPX7100AP, MPX7100AS, MPX7100GVSX Datasheet

MOTOROLA

SEMICONDUCTOR TECHNICAL DATA

Order this document by MPX7100/D

100 kPa
High Z , On-Chip	Temperature
in
Compensated &	Calibrated

Silicon Pressure Sensors

The new MPX7100 series pressure sensor incorporates all the innovative features of Motorola's MPX2000 series family including the patented, single piezoresistive strain gauge (X±ducer) and on±chip temperature compensation and calibration. In addition, the MPX7100 series has a high input impedance of typically 10 kΩ for those portable, low power and battery±operated applications. This device is suitable for those systems in which users must have a dependable, accurate pressure sensor that will not consume significant power. The MPX7100 series device is a logical and economical choice for applications such as portable medical instrumentation, remote sensing systems with 4±20 mAmp transmission and field barometers/altimeters.

Features

•Temperature Compensated Over 0°C to +85°C

•Unique Silicon Shear Stress Strain Gauge

•Easy to Use Chip Carrier Package Options

•Available in Differential and Gauge Configurations

•Ratiometric to Supply Voltage

•±0.25% Linearity (MPX7100D)

Application Examples

•Portable Medical Instrumentation

•Field Altimeters

•Field Barometers

Figure 1 illustrates a schematic of the internal circuitry on the stand±alone pressure sensor chip.

		VS
		3
	HIGH	THIN FILM	2
		TEMPERATURE		Vout+
	Zin
		COMPENSATION
	X±ducer
		AND	4
	SENSING			Vout±
		CALIBRATION
	ELEMENT
		CIRCUITRY
		1
		GND

MPX7100

SERIES

Motorola Preferred Device

0 to 100 kPa (0 to 14.5 psi)

40 mV FULL SCALE SPAN (TYPICAL)

BASIC CHIP

CARRIER ELEMENT

CASE 344±15, STYLE 1

DIFFERENTIAL

PORT OPTION

CASE 344C±01, STYLE 1

NOTE: Pin 1 is the notched pin.

PIN NUMBER

1	Gnd	3	VS
2	+Vout	4	±Vout

Figure 1. Temperature Compensated Pressure Sensor Schematic

VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE

The differential voltage output of the X±ducer is directly proportional to the differential pressure applied.

The absolute sensor has a built±in reference vacuum. The output voltage will decrease as vacuum, relative to ambient, is drawn on the pressure (P1) side.

The output voltage of the differential or gauge sensor increases with increasing pressure applied to the pressure (P1) side relative to the vacuum (P2) side. Similarly, output voltage increases as increasing vacuum is applied to the vacuum (P2) side relative to the pressure (P1) side.

Preferred devices are Motorola recommended choices for future use and best overall value.

Senseon and X±ducer are trademarks of Motorola, Inc.

REV 3

Motorola Sensor Device Data	1
Motorola, Inc. 1997

MPX7100 SERIES

MAXIMUM RATINGS

Rating			Symbol				Value			Unit
Overpressure(8) (P1 > P2)			Pmax			400				kPa
Burst Pressure(8) (P1 > P2)			P			1000				kPa
			burst
Storage Temperature			Tstg			± 40 to +125				°C
Operating Temperature			TA			± 40 to +125				°C
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic			Symbol	Min			Typ		Max		Unit
Pressure Range(1)			P	0			Ð		100		kPa
			OP
Supply Voltage(2)			VS	Ð			10		16		Vdc
Supply Current			Io	Ð			1.0		Ð		mAdc
Full Scale Span(3)	MPX7100A, MPX7100D		V	38.5			40		41.5		mV
			FSS
Offset(4)	MPX7100D		Voff	±1.0			Ð		1.0		mV
	MPX7100A			± 2.0			Ð		2.0
Sensitivity			V/ P	Ð			0.4		Ð		mV/kPa
Linearity(5)	MPX7100D		Ð	± 0.25			Ð		0.25		%VFSS
	MPX7100A		Ð	± 1.0			Ð		1.0
Pressure Hysteresis(5) (0 to 100 kPa)			Ð	Ð			± 0.1		Ð		%V
											FSS
Temperature Hysteresis(5) (± 40°C to +125°C)			Ð	Ð			± 0.5		Ð		%V
											FSS
Temperature Effect on Full Scale Span(5)			TCV	±1.0			Ð		1.0		%V
			FSS								FSS
Temperature Effect on Offset(5)			TCVoff	±1.0			Ð		1.0		mV
Input Impedance			Zin	5000			10,000		15,000		Ω
Output Impedance			Zout	2500			3100		6000		Ω
Response Time(6) (10% to 90%)			tR	Ð			1.0		Ð		ms
Warm±Up			Ð	Ð			20		Ð		ms
Offset Stability(9)			Ð	Ð			± 0.5		Ð		%V
											FSS
MECHANICAL CHARACTERISTICS
Characteristic			Symbol	Min			Typ		Max		Unit
Weight (Basic Element Case 344±15)			Ð	Ð			2.0		Ð		Grams
Common Mode Line Pressure(7)			Ð	Ð			Ð		690		kPa
NOTES:

1.1.0 kPa (kiloPascal) equals 0.145 psi.

2.Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional error due to device self±heating.

3.Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the minimum rated pressure.

4.Offset (Voff) is defined as the output voltage at the minimum rated pressure.

5.Accuracy (error budget) consists of the following:

•	Linearity:	Output deviation from a straight line relationship with pressure, using end point method, over the specified
		pressure range.
•	Temperature Hysteresis:	Output deviation at any temperature within the operating temperature range, after the temperature is
		cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
		applied.
•	Pressure Hysteresis:	Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
		minimum or maximum rated pressure, at 25°C.
•	TcSpan:	Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
•	TcOffset:	Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
		to 25°C.

6.Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to a specified step change in pressure.

7.Common mode pressures beyond specified may result in leakage at the case±to±lead interface.

8.Exposure beyond these limits may cause permanent damage or degradation to the device.

9.Offset stability is the product's output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.

2	Motorola Sensor Device Data

LINEARITY

Linearity refers to how well a transducer's output follows the equation: Vout = Voff + sensitivity x P over the operating pressure range. There are two basic methods for calculating nonlinearity: (1) end point straight line fit (see Figure 2) or (2) a least squares best line fit. While a least squares fit gives the ªbest caseº linearity error (lower numerical value), the calculations required are burdensome.

Conversely, an end point fit will give the ªworst caseº error (often more desirable in error budget calculations) and the calculations are more straightforward for the user. Motorola's specified pressure sensor linearities are based on the end point straight line method measured at the midrange pressure.

		MPX7100		SERIES
	LEAST SQUARES FIT
OUTPUT	EXAGGERATED
	PERFORMANCE
	CURVE	LEAST	STRAIGHT LINE
			DEVIATION
VOLTAGE
		SQUARE
		DEVIATION
RELATIVE	END POINT
	STRAIGHT LINE FIT
	OFFSET
0	50		100

PRESSURE (% FULLSCALE)

Figure 2. Linearity Specification Comparison

ON±CHIP TEMPERATURE COMPENSATION and CALIBRATION

Figure 3 shows the output characteristics of the MPX7100 series at 25°C. The output is directly proportional to the differential pressure and is essentially a straight line.

The effects of temperature on Full Scale Span and Offset are very small and are shown under Operating Characteristics.

		40
		35
	(mVdc)	30
		25
	OUTPUT
		20

15

10

5

0

± 5 kPa 0

PSI

VS = 10 Vdc
TA = 25°C
P1 > P2	TYP
MAX				SPAN
				RANGE
				(TYP)
	MIN
25	50	75	100	OFFSET
				(TYP)
3.62	7.25	10.87	14.5

Figure 3. Output versus Pressure Differential

SILICONE GEL	DIFFERENTIAL/GAUGE	STAINLESS STEEL	SILICONE GEL	ABSOLUTE	STAINLESS STEEL
DIE COAT	DIE	METAL COVER	DIE COAT	DIE	METAL COVER
	P1
		EPOXY		P1	EPOXY
WIRE BOND			WIRE BOND
		CASE			CASE
LEAD FRAME		DIE	LEAD FRAME		DIE
DIFFERENTIAL/GAUGE ELEMENT		BOND
				ABSOLUTE ELEMENT	BOND
	P2			P2

Figure 4. Cross±Sectional Diagrams (Not to Scale)

Figure 4 illustrates the absolute sensing configuration (right) and the differential or gauge configuration in the basic chip carrier (Case 344±15). A silicone gel isolates the die surface and wire bonds from the environment, while allowing the pressure signal to be transmitted to the silicon diaphragm.

The MPX7100 series pressure sensor operating charac-

teristics and internal reliability and qualification tests are based on use of dry air as the pressure media. Media other than dry air may have adverse effects on sensor performance and long term reliability. Contact the factory for information regarding media compatibility in your application.

Motorola Sensor Device Data

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