AK8448 Datasheet, PDF (47/53 Pages) Asahi Kasei Microsystems – 6-Channel Linear Sensor compatible 10 Bit 40 MSPS x 3 Analog Pre-Processor

ASAHI KASEI
[AK8448]
Serial I / F
Write operation into and Read operation from Control registers are executed via a 4 –
wire Serial Interface.
SDIN data while SDENB is at low is taken at the rising edge of SDCLK.
When the starting bit of SDIN data is “ zero “, writing into register is made and when it is
“ one “, reading from register is made.
The second and the third bits ( C1, C0 ) correspond to CE1 and CE0 pin data
respectively and only when logical levels are at C1 = CE1 and C0 = CE0, either write in
or read out operation is enabled.
The fourth bit must be zero.
Bits from the fifth to the eighth are for register address. MSB is the fifth bit and LSB is the
eighth bit.
Bits from ninth to sixteenth are data for register. MSB ( = D7 ) is the ninth bit and LSB ( =
D0 ) is the sixteenth bit.
„ Reset
Register values at the power-up are indeterminate including registers for test.
In order to avoid test registers from disturbing normal operation, a reset should be made
right after the power-up.
When RESETB pin is set to low, each register is set to its default value while test
registers are set to necessary values for normal operation.
Low duration time of RESETB should be 100 ns and longer.
Return RESETB pin to high after the reset, and necessary value should be written to
each register. When reset is not made after power-up, write default values into test
registers.
„ Power-Down
The AK8448 enters power-down mode when operation mode register R0,D1 is set at “ 1
“. In power-down mode, supplying operation clock to Digital part is also stopped while
current supply to Analog part is ceased.
When returning to normal operation from power-down mode ( R0, D0 = 0 ), a wait time is
required so that VCOM ( reference voltage ) is stabilized to its normal voltage since
VCOM is made to 0 V at power-down.
MS1513-E-00
47
2013/02