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The frequency characteristic (theorical value) when the recommended constants are used is shown below.

Fig.31

Low-band corrective circuit Frequency characteristic

●

CPU INTERFACE

BU7858KN and BU7893GU can be controlled by using CPU interface.

【

BU7858KN】

Fig.32

CPU I/F Timing Chart 1 (BU7858KN)

After the falling edge of NCS, SDATA inputs are settled by 16 clock of SCLK, and data is written in the rising edge of NCS.

The data format is “16bit right justified”.

CPU interface is that 1Byte=16bit. It is absolutely necessary to insert the interval of NCS=“H” between first Byte and

Second Byte because it is not compatible with continuous data transmission. For the following th, please wait the time more

than 1 SCLK Clock. (th≧tcyc)

Fig.33

CPU I/F Timing Chart 2 (BU7858KN)

・

AC Characteristics

Ta=25℃、AVDD=DVDD=3.0V

Item

Symbol

Min

Typ

Max

Unit

Conditions

SCLK Width

tcyc

250

-

-

ns

SDATA Input Hold Time

tdh

50

-

-

ns

SDATA Input Set-up Time

tds

50

-

-

ns

NCS Set-up Time

tcs

50

-

-

ns

NCS Hold Time

tch

50

-

-

ns

It is recommended to use exclusive lines for CPU interface.

-40

-35

-30

-25

-20

-15

-10

-5

0

5

10

1

10

100

1000

10000

100000

Frequency [Hz]

After correction

Before correction

Amplifier output

A7

SCLK

SDATA

tcs

NCS

tds

tdh

A6

D6

D5

D4

D3

D2

D1

D0

A5

A4

A3

A2

D7

A1

tch

tcyc

A0

NCS

SC L K

S DA TA

th