DA5534B_003.doc

February 28th, 2005

15

00005534B784

ECN 711

DECOUPLING CAPACITOR

Particular care must be taken when connecting the device to power supply. A 47

µF tantalum capacitor must be

placed as close as possible of the MS5534B's VDD pin. This capacitor will stabilise the power supply during data

conversion and thus, provide the highest possible accuracy.

APPLICATION EXAMPLE: ALTIMETER SYSTEM USING MS5534B

MS5534B is a circuit that can be used in connection with a microcontroller in mobile altimeter applications. It is

designed for low-voltage systems with a supply voltage of 3 V, particularly in battery applications. The MS5534B

is optimised for low current consumption as the AD-converter clock (MCLK) can use the 32.768 kHz frequency of

a standard watch crystal, which is supplied in most portable watch systems.

For applications in altimeter systems Intersema can deliver a simple formula to calculate the altitude, based on a

linear interpolation, where the number of interpolation points influences the accuracy of the formula.

4/8bit-Microcontroller

LCD-Display

EEPROM

Keypad

MS5534

SCLK

DIN

DOUT

MCLK

XTAL1

XTAL2

32.768 kHz

optional

VDD

GND

VDD

VSS

3V-Battery

47uF

Tantal

Figure 7: Demonstration of MS5534B in a mobile altimeter.