ETC2 HP01-TQ Low voltage, low power Datasheet

Hope RF
HP01-TQ
BAROMETER MODULE
2011-4-20
PRELIMINARY
Version: 2.2
. Integrated pressure sensor
. Pressure Range 750-1100hpa
. 16 Bit Σ−Δ ADC
. I2C Serial Interface
. One system clock line (32768Hz)
. Low voltage, low power
Description
The HP01 pressure module includes a piezo-resistive pressure sensor and an ADC
interface. It provides 16 bit word data for pressure and temperature related voltage. HP01
is a low power, low voltage device with automatic power down switching. I2C Serial
Interface is used for communications with a microprocessor.
Features
. 14 Bit ENOB ADC resolution
. Supply voltage 2.2-3.6v
. -40°C to + 85°C operating range
Applications
. Pressure measurement and control systems
. Weather forecast products
Block Diagram
1
Hope RF
HP01-TQ
BAROMETER MODULE
PRELIMINARY
2011-4-20
Version: 2.2
Pin Name
VSS
VDD
MCLK
XCLR*
SDA
Pin Number
1
2
3
4
5
Type
G
P
I
I
I/O
Function
power ground
power VCC
master clock(32k) input
ADC reset inpu
. I²C data input and output
SCL
6
I
I2C clock input
* XCLR is to reset the AD converter (active low). During the AD conversion phase, XCLR should stay
high. After AD conversion end, keep XCLR pin low before another AD conversion starts.
Absolute Maximum Ratings
Parameter
Supply Voltage
Over pressure
Symbol
VDD
P
Min
-0.3
Max
4.0
5
Unit
V
Bar(abs)
Storage Temperature
Tstg
-40
125
°C
Recommended Operating Conditions
Parameter
Supply Voltage
Supply Current
Symbol
VDD
I
Conditions
Min
2.2
Typ
3
Unit
V
V
VDD=3V
During conversion
μΑ
μΑ
500
Stand by
Operating Pressure Range
Operating Temperature Range
Conversion Time
Duty Cycle of MCLK
Serial Date Rate
Max
3.6
1
P
900
T
T
-40
25
MCLK=32k
40%
50%
SCL
1100
Hpa (abs)
85
35
60%
100
°C
ms
%
KHZ
Pressure and Temperature Output Characteristics
HP01 system is able to reach the following characteristics:
Parameter
Resolution
Accuracy
Symbol
Pressure Sensitivity
SNS
Conditions
Maximum Error Over Temperature
Long Term Stability
VDD Dependency
Temperature coefficient of sensitivity
TCS
2
Typ
900-1100
Min
0.1
-8
900-1100
25
27
0~+55
12 month
2.0~5.0
-5.0
Max
+10
Unit
hpa
hpa
30
Cnts/mbar
5.0
-1.5
1
0
1.5
hpa
hpa
hpa
-0.45
-0.55
-0.6
∆D1/∆D2
Hope RF
HP01-TQ
BAROMETER MODULE
PRELIMINARY
2011-4-20
Version: 2.2
Pressure Measurement
The main function of HP01 system is to convert the uncompensated pressure and
temperature signal from a pressure sensor. After the conversion, the following two values
can be obtained:
. measured temperature
“D2”
. measured pressure
“D1”
As the sensor is strongly temperature dependent, it is necessary to compensate for these
effects. Therefore necessary temperature compensation is needed to achieve nominal
accuracy.
Pressure and Temperature Compensation Calculation:
The following information is just a guide line for temperature
compensate, the end user of this module should not be confined
to this method. Many other methods can be deployed to achieve
best accuracy.
Step 1: (set relative pressure starting reference point, normally this step be done after
power up or reset relative pressure)
P0=1013.2hp
D1(P0)=D1
D2(P0)=D2
Step 2: (normal pressure calculation with first order temperature compensation)
dUT=D2-D2(P0)
dTCS=TCS*dUT
dUP=D1-dTCS-D1(P0)
P2=dUP/SNS
P=P0+P2
; calculate current temperature difference with reference temperature
; calculate compensated pressure offset with temperature coefficients
; calculate temperature compensated pressure reading
; calculate pressure difference referred to starting pressure P0
; calculate current relative pressure
Example:
D1(P0)=30000
D2(P0)=4100
TCS=-0.55
SNS=27
(obtained after power up reading: D1)
(obtained after power up reading: D2)
(nominal module value from this data sheet)
(nominal module value from this data sheet)
D1=30036
D2=4107
(current pressure AD reading from module)
(current temperature AD reading from module)
dUT = 4107-4100 = 7
dTCS=-0.55*7=-3.85
dUP=30036+3.85-30000=39
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Hope RF
HP01-TQ
BAROMETER MODULE
2011-4-20
PRELIMINARY
Version: 2.2
P2=39/27=1.44
P=1013.2+1.44=1014.6
Serial Interface
The I2C interface is used for reading measurement result from AD conversion:D1 and D2.
Reading Temperature and Pressure value:D1,D2
AD chip I2C address is set to 0xEE (device write address), 0xEF (device read
address). In order to get the AD value D1 and D2, you have to follow the following
timing sequence:
Pressure Measure:
S 11101110 A 11111111 A 11110000 A P D S 11101110 A 11111101 A S 11101111 A MSB A LSB N P
Select pressure measurement
Read AD value back
Temperature Measure:
S 11101110 A 11111111 A 11101000 A P D S 11101110 A 11111101 A S 11101111 A MSB A LSB N P
Select temperature measurement
Read AD value back
S: I2C bus START (refer to AT24C02 EEPROM start command)
P: I2C bus STOP (refer to AT24C02 EEPROM stop command)
A (bold): I2C bus acknowledge by slave (SDA pull low: slave send out bit 0)
A: I2C bus acknowledge by master (SDA pull low: master send out bit 0)
N: I2C bus no acknowledge from master (SDA keep high: master send out bit 1 instead)
D : delay for 38ms or above
MSB: conversion result (MSB bit clocked out first)
LSB: conversion result (MSB bit clocked out first).
Remark:
Before start an AD conversion cycle, remember to set XCLR pin high so that the system
is no longer in the reset state (not valid for HP01).
4
Hope RF
HP01-TQ
BAROMETER MODULE
2011-4-20
PRELIMINARY
Version: 2.2
All data read from the module is in hex format.
After first power on, the first read data should be disregarded, and only the second value
be used. This can assure that unstable reading after power on reset can be filtered out.
Like any other semiconductor device, the sensor is sensitive to light. During the
application of this sensor, please keep the sensor in dark place to achieve best accuracy.
Since the module is not calibrated for sensitivity and temperature, thus only relative pressure can be
calculated. If you need higher accuracy with temperature, please refer to our HP02 or HP03 series
pressure module accordingly.
Typical Application Circuit Diagram:
Remark:
In the battery supply product this application need be changed as:
32 KHz signal is outputted via the port of the MCU instead of the 32.768 KHz crystal to
MCLK pin. The MCU will not output 32 KHz signal and keep low level when the HP01
enter to standby mode.
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Hope RF
HP01-TQ
BAROMETER MODULE
2011-4-20
PRELIMINARY
Version: 2.2
HP01-TQ Mechanical Dimension
Important Notices
Never unplug the module when power is on.
Do not use this product as safety or emergency stop device or in any application where
failure of this product could lead in personal injury. Failure to comply with these
instructions could result with death or serious injury.
Should buyer purchase or use HOPE RF products for any such unintended or
unauthorized application, buyer should indemnify and hold HOPE RF and its officers,
employees, affiliates and distributors harmless against all claims, costs, damages and
expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of
personal injury associated with such unintended or unauthorized use, even if such claim
alleges that HOPE RF was negligent regarding the design or manufacturing of the part.
Hope RF reserves the right, without further notice, to change the product specification
and/or information in this document and to improve reliability, functions and design.
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