MAX5478EUD+ Maxim Integrated Products, MAX5478EUD+ Datasheet - Page 13

• Manufacturer Part Number: MAX5478EUD+
• Description: IC POT DGTL DUAL 256-TAP 14TSSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX5478EUD+

• Taps: 256
• Resistance (ohms): 50K
• Number Of Circuits: 2
• Temperature Coefficient: 35 ppm/°C Typical
• Memory Type: Non-Volatile
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.7 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 14-TSSOP
• Resistance In Ohms: 50K
• Number Of Pots: Dual
• Taps Per Pot: 256
• Resistance: 325 Ohms
• Wiper Memory: Non Volatile
• Digital Interface: Serial (2-Wire)
• Operating Supply Voltage: 2.7 V to 5.25 V
• Supply Current: 1 uA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Description/function: Dual, 256 Tap, Nonvolatile, I2C, 50k Digital Potentiometer
• Mounting Style: SMD/SMT
• Supply Voltage (max): 5.25 V
• Supply Voltage (min): 2.7 V
• Tolerance: 25 %
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3 bits in the slave address. Connect each address input
to V
have a unique address to share a common bus.
Write to the MAX5477/MAX5478/MAX5479 by transmit-
ting the device’s slave address with NOP/W (8th bit) set
to zero, followed by at least 1 byte of information
(Figure
byte. The bytes received after the command byte are
the data bytes. The 1st data byte goes into the internal
register of the MAX5477/MAX5478/MAX5479 as select-
ed by the command byte
Figure 5. Bit Transfer
Figure 7. Command Byte Received
Figure 8. Command and Single Data Byte Received
SDA
SCL
S
DD
HOW CONTROL BYTE AND DATA BYTE MAP INTO
or GND to set these 3 bits. Each device must
7). The 1st byte of information is the command
S
MAX5477/MAX5478/MAX5479 REGISTERS
DATA STABLE,
DATA VALID
SLAVE ADDRESS
COMMAND BYTE IS STORED ON RECEIPT OF STOP CONDITION
Dual, 256-Tap, Nonvolatile, I
MAX5477/MAX5478/MAX5479
______________________________________________________________________________________
Message Format for Writing
CHANGE OF
DATA ALLOWED
ACKNOWLEDGE FROM
SLAVE ADDRESS
(Figure
NOP/W
MAX5477/MAX5478/MAX5479
8).
0
ACKNOWLEDGE FROM
A
D15 D14 D13 D12 D11 D10
NOP/W
0
MAX5477/MAX5478/MAX5479
COMMAND BYTE
ACKNOWLEDGE FROM
A
D15
Use the command byte to select the source and desti-
nation of the wiper data (nonvolatile or volatile memory
registers) and swap data between nonvolatile and
volatile memory registers (see
VREG: The data byte writes to the volatile memory reg-
ister and the wiper position updates with the data in the
volatile memory register.
NVREG: The data byte writes to the nonvolatile memory
register. The wiper position is unchanged.
NVREGxVREG: Data transfers from the nonvolatile
memory register to the volatile memory register (wiper
position updates).
Figure 6. Acknowledge
Digital Potentiometers
SDA
SCL
CONDITION
D14
D9
START
D13
D8
COMMAND BYTE
A
D12
1
D7
MAX5477/MAX5478/MAX5479
D11
D6
2
ACKNOWLEDGE FROM
D10
D5
MAX5477/MAX5478/MAX5479
2
C-Interface,
DATA BYTE
D4
1 BYTE
ACKNOWLEDGE FROM
D9
NOT ACKNOWLEDGE
Table
Command Descriptions
D3
ACKNOWLEDGE
D8
D2
8
ACKNOWLEDGMENT
3).
CLOCK PULSE FOR
Command Byte
A
D1
D0
9
P
A
P
13