MMA7455LT Freescale Semiconductor, MMA7455LT Datasheet - Page 15
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MMA7455LT
Manufacturer Part Number
MMA7455LT
Description
Board Mount Accelerometers 3-AXIS DIGITAL 2 4 8G
Manufacturer
Freescale Semiconductor
Datasheet
1.MMA7455LT.pdf
(35 pages)
Specifications of MMA7455LT
Sensing Axis
X, Y, Z
Acceleration
2 g, 4 g, 8 g
Supply Voltage (max)
3.6 V
Supply Voltage (min)
2.4 V
Supply Current
400 uA
Maximum Operating Temperature
+ 85 C
Minimum Operating Temperature
- 40 C
Sensitivity
64 LSB/g
Package / Case
LGA-14
Output Type
Digital
Acceleration Range
± 2g, ± 4g, ± 8g
No. Of Axes
3
Sensor Case Style
LGA
No. Of Pins
14
Supply Voltage Range
2.4V To 3.6V
Operating Temperature Range
-40°C To +85°C
Filter Terminals
SMD
Rohs Compliant
Yes
Ic Interface Type
I2C, SPI
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
MMA7455LT
Manufacturer:
FREESCALE
Quantity:
18 300
Part Number:
MMA7455LT
Manufacturer:
FREESCALE
Quantity:
20 000
ASSIGNING, CLEARING & DETECTING INTERRUPTS
Assigning the interrupt pins is done in Register $18. There are 3 combinations for the interrupt pins to be assigned which are
outlined below in the table for INTREG[1:0].
Table 7. Configuring the Interrupt settings using Register $18 with INTREG[1:0] bits
00: INT1 Register is detecting Level while INT2 is detecting Pulse.
01: INT1 Register is detecting Pulse while INT2 is detecting Level.
10: INT1 Register is detecting a Single Pulse and INT2 is detecting Single Pulse (if 2
time window and second time window > 0 then INT2 will detect the double pulse only.
INTPIN: INT1 pin is routed to INT1 bit in Detection Source Register ($0A) and INT2 pin is routed to INT2 bit in Detection Source
Register ($0A).
INTPIN: INT2 pin is routed to INT1 bit in Detection Source Register ($0A) and INT1 pin is routed to INT2 bit in Detection Source
Register ($0A).
Note: When INTREG[1:0] =10 for the condition to detect single pulse on INT1 and either single or double pulse on INT2, INT1
register bit can no longer be cleared by setting CLR_INT1 bit. It is cleared by setting CLR_INT2 bit. In this case, setting CLR_INT2
clears both INT1 and INT2 register bits and resets the detection operation. Follow the example given for clearing the interrupts.
Clearing the Interrupt Pins: Register $17
CLR_INT1
1: Clear “INT1”
0: Do not clear “INT1”
CLR_INT2
1: Clear “INT2”
0: Do not clear “INT2”
After interrupt has triggered due to a detection, the interrupt pin (INT1 or INT2) need to be cleared by writing a logic 1. Then the
interrupt pin should be enabled to trigger the next detection by setting it to a logic 0.
This example is to show how to reset the interrupt flags
void ClearIntLatch(void)
{
IIC_ByteWrite(INTRST, 0x03);
IIC_ByteWrite(INTRST, 0x00);
}
$18 Control 1 Register
$17: Interrupt Latch Reset (Read/Write)
Sensors
Freescale Semiconductor
DFBW
D7
D7
0
--
0
INTREG[1:0]
00
01
10
THOPT
D6
D6
--
0
0
ZDA
D5
D5
--
0
0
Single Pulse detection
“INT1” Register Bit
Pulse Detection
Level detection
YDA
D4
D4
--
0
0
XDA
D3
D3
--
0
0
INTREG[1]
D2
D2
--
0
0
nd
INTREG[0]
Time Window = 0) or if there is a latency
CLR_INT2
Single or Double Pulse Detection
D1
D1
0
0
“INT2” Register Bit
Pulse Detection
Level Detection
CLR_INT1
INTPIN
D0
D0
0
0
MMA7455L
Function
Function
Reg $18
Reg $17
Default
Default
15