–16–

8-Lead SOIC

(SO-8)

0.0098 (0.25)

0.0075 (0.19)

0.0500 (1.27)

0.0160 (0.41)

8

0

0.0196 (0.50)

0.0099 (0.25)

45

85

4

1

0.1968 (5.00)

0.1890 (4.80)

0.2440 (6.20)

0.2284 (5.80)

PIN 1

0.1574 (4.00)

0.1497 (3.80)

0.0500 (1.27)

BSC

0.0688 (1.75)

0.0532 (1.35)

SEATING

PLANE

0.0098 (0.25)

0.0040 (0.10)

0.0192 (0.49)

0.0138 (0.35)

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

AD7898 to MC68HC16 Interface

The Serial Peripheral Interface (SPI) on the MC68HC16 is

configured for Master Mode (MSTR = 1), Clock Polarity Bit

(CPOL) = 1 and the Clock Phase Bit (CPHA) = 0. The SPI is

configured by writing to the SPI Control Register (SPCR) (see

68HC16 user manual). The serial transfer will take place as a

16-bit operation when the SIZE bit in the SPCR register is set

to SIZE = 1. To implement the power-down modes with an

8-bit transfer set SIZE = 0. A connection diagram is shown in

ply voltage as that of the MC68HC16. This allows the ADC

to operate at a higher voltage than the serial interface, i.e.,

MC68HC16, if necessary.

AD7898*

MC68HC16*

SCLK/PMC2

MISO/PMC0

SS/PMC3

*ADDITIONAL PINS OMITTED FOR CLARITY

CS

SCLK

SDATA

Figure 20. AD7898 to MC68HC16 Interface

AD7898

REV. 0