DS3906 MAXIM [Maxim Integrated Products], DS3906 Datasheet - Page 8

• Manufacturer Part Number: DS3906
• Description: Triple NV Low Step Size Variable Resistor Plus Memory
• Manufacturer: MAXIM [Maxim Integrated Products]

Triple NV Low Step Size Variable
Resistor Plus Memory
makes the corresponding resistor go High-Z. Plots for
both resistor sizes are shown on the front page of this
data sheet. It can be seen that, when an external resis-
tor is connected in parallel with the DS3906’s resistors,
the effective resistance is linear and capable of achiev-
ing sub-ohm and ohm steps.
The resistor settings are stored in EEPROM memory. It
is important to point out that the DS3906 EEPROM is
organized in 2-byte pages. This is transparent when
Table 1. DS3906 Memory Map
Table 2. DS3906 Resistor Registers
* Writing a value greater than 3Fh to any of the resistor registers makes the corresponding resistor go High-Z. Position 3Fh is the
maximum position.
8
00h to 0Fh
F8h
F9h
FAh
FBh-FFh
ADDRESS
_____________________________________________________________________
ADDRESS
F8h
F9h
FAh
EEPROM
EEPROM
EEPROM
EEPROM
TYPE
VARIABLE RESISTOR
Resistor 0
Resistor 1
Resistor 2
User memory
Resistor 0
Resistor 1
Resistor 2
NAME
16 bytes of general-purpose user EEPROM.
Resistor 0-2 settings. See Table 2 and the Resistor
Registers/Settings section.
POSITION 3FH RESISTANCE
reading from the device or when performing single byte
writes. However, this limits the maximum number of
bytes that can be written in one I
Furthermore, the multiple byte writes must begin on
even memory addresses (00h, 02h, …., F8h, etc).
Additional information is provided later in the I
Communication section . Example communication
transactions are provided in Figure 3.
Reserved
(kΩ)
2.54
2.54
1.45
FUNCTION
NUMBER OF POSITIONS*
64 (00h to 3Fh) + High-Z
2
C transaction to two.
FACTORY
DEFAULT
00h
3Fh
3Fh
3Fh
2
C