BU7858KN_10 Datasheet, PDF (12/25 Pages) Rohm – Mixer & Selector ICs with 16bit D/A Converter

BU7858KN,BU7893GU
Technical Note
The frequency characteristic (theorical value) when the recommended constants are used is shown below.
10
5
0
Amplifier output
-5
After correction
-10
-15
Before correction
-20
-25
-30
-35
-40
1
10
100
1000
10000
100000
Frequency [Hz]
Fig.31 Low-band corrective circuit Frequency characteristic
●CPU Interface
BU7858KN and BU7893GU can be controlled by using CPU interface.
【BU7858KN】
NCS
SCLK
SDATA
tcs
tcyc
tch
tds
tdh
A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
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)
th
NCS
SCLK
SDATA
Fig.33 CPU I/F Timing Chart 2 (BU7858KN)
・AC Characteristics
Ta=25℃, AVDD=DVDD=3.0V
Parameter
Limits
Symbol
Unit
Min. Typ. Max.
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.
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12/24
Conditions
2010.09 - Rev.A