BU9831 Datasheet, PDF (6/13 Pages) Rohm – Non-volatile electronic potentiometer

Memory ICs
BU9831 / BU9831F
•^{Command modes}
Command
Write enabled
WEN
Write disabled
WDS
Wiper counter data output
WCR
Wiper counter data input
WCW
Data read
DRD
Data write
DWR
Transmission memory data read TDWR
Transmission memory data write TWDW
Increment / decrement wiper INC/DEC
Start bit Operation code Address
Data
Operation
1010
0011 XXXXXXXX
—
—
1010
0000 XXXXXXXX
—
—
1010
1011 XXXXXXXX D8 - D14 X
Wiper counter → output
1010
0110 XXXXXXXX XXXXXXXX D8 - D14 X Input → wiper counter
1010
1000 A0 - A6 X D0 - D15
Memory → output
1010
0100 A0 - A6 X D0 - D15
Input → memory
1010
1001 A0 - A6 X
—
Memory → wiper counter
1010
0101 A0 - A6 X
—
Wiper counter → memory
1010
1111
—
Wiper counter → INC / DEC
X: Don't Care (data may be either 0 or 1)
á­ºAuto recall function (ARF)
• After the power supply is turned on, the data for address 00h is automatically loaded and the wiper position set. At
this point, if the data for address 00h is larger than 64h, the wiper position is set to 32h. Since the wiper position is
set using seven bits, the eighth bit may be set to any value. This function is carried out 10ms after the power supply
is turned on, and subsequently the IC enters the standby state.
•^{Operation timing characteristics (unless otherwise noted, Ta = – 20 to + 85°C, VCC = 5V ± 10%)}
Parameter
Symbol Min. Typ. Max. Unit
CS setup time
tCSS 200 —
—
ns
CS hold time
tCSH
0
— — ns
Data setup time
tDIS 150 —
—
ns
Data hold time
tDIH 150 —
—
ns
DO rise delay time
tPD1
—
— 350 ns
DO fall delay time
tPD0
—
— 350 ns
Self-timed programming cycle
tE / W — — 10 ms
CS minimum HIGH time
tCS
1
—
—
µs
Time during which READY / BUSY display is effective tSV
—
—
1
µs
Time that DO is HIGH-Z from (CS)
tOH
0
— 400 ns
Data clock HIGH time
tWH 450 —
—
ns
Data clock LOW time
tWL 450 —
—
ns
Resistance value stabilization time
tAW
—
— 500 µs
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