MPL115A1_13 Datasheet, PDF (11/16 Pages) Freescale Semiconductor, Inc – Miniature SPI Digital Barometer

Using the evaluation sequence shown in Section 3.3:
c12x2 = c12 * Tadc = 0.00086665 * 513
= 0.44459
a1
= b1 + c12x2 = -2.49512 + 0.44459
= -2.05052
a1x1 = a1 * Padc = -2.05052 * 415
= -850.96785
y1
= a0 + a1x1 = 2107.875 + (-850.96785) = 1256.90715
a2x2 = b2 * Tadc = -1.02069 * 513
= -523.61444
PComp = y1 + a2x2 = 1256.90715 + (-523.61444) = 733.29270
Pressure (kPa) = Pcomp ⋅
1----1---5-----–_----5----0--
1023
+ 50
= 733.29 ⋅
1----1---5-----–_-----5---0--
1023
+ 50
= 96.59kPa
4 Solder Recommendations
1. Use SAC solder alloy (i.e., Sn-Ag-Cu) with a melting point of about 217°C. It is recommended to use SAC305
(i.e., Sn-3.0 wt.% Ag-0.5 wt.% Cu).
2. Reflow
NOTE:
• Ramp up rate: 2 to 3°C/s.
• Preheat flat (soak): 110 to 130s.
• Reflow peak temperature: 250°C to 260°C (depends on exact SAC alloy composition).
• Time above 217°C: 40 to 90s (depends on board type, thermal mass of the board/quantities in the reflow).
• Ramp down: 5 to 6°C/s.
• Using an inert reflow environment (with O₂ level about 5 to 15 ppm).
The stress level and signal offset of the device also depends on the board type, board core material, board thickness
and metal finishing of the board.
Sensors
Freescale Semiconductor, Inc.
MPL115A1
11