MAX5395 MAXIM [Maxim Integrated Products], MAX5395 Datasheet - Page 11

• Manufacturer Part Number: MAX5395
• Description: Single, 256-Tap Volatile, I2C, Low-Voltage Linear Taper Digital Potentiometer
• Manufacturer: MAXIM [Maxim Integrated Products]

SDA and SCL idle high when the bus is not in use. A mas-
ter initiates communication by issuing a START condition.
A START condition is a high-to-low transition on SDA with
SCL high. A STOP condition is a low-to-high transition
on SDA while SCL is high
from the master signals the beginning of a transmission
to the MAX5395. The master terminates transmission
and frees the bus, by issuing a STOP condition. The bus
remains active if a Repeated START condition is gener-
ated instead of a STOP condition.
The MAX5395 recognizes a STOP condition at any point
during data transmission except if the STOP condition
occurs in the same high pulse as a START condition.
For proper operation, do not send a STOP condition dur-
ing the same SCL high pulse as the START condition.
Transmissions ending in an early STOP condition will not
impact the internal device settings. If the STOP occurs
during a readback byte, the transmission is terminated
Figure 3. I
Figure 2. I
SDA
SCL
CONDITION
Single, 256-Tap Volatile, I
SDA
SCL
I
START
2
C Early STOP and Repeated START Conditions
(S)
t
HD:STA
2
2
C START(s), Repeated START(S), and STOP(S) Conditions
C Timing Diagram
S
VALID START, REPEATED START, AND STOP PULSES
t
LOW
t
SU:DAT
t
R
I
2
C START and STOP Conditions
t
HIGH
(Figure
t
F
Sr
t
HD-DAT
2). A START condition
P
t
Taper Digital Potentiometer
SU:DTA
START CONDITION
REPEATED
(Sr)
and a later read mode request will begin transfer of the
requested register data from the beginning. See
It is possible to interrupt a transmission to a MAX5395
with a new START (Repeated START) condition (perhaps
addressing another device), which leaves the input regis-
ters with data that has not been transferred to the internal
registers. The unused data will not be stored under these
conditions. The aborted MAX5395 I
have no effect on the part.
In write mode, the acknowledge bit (ACK) is a clocked
9th bit that the MAX5395 uses to handshake receipt of
each byte of data as shown in
pulls down SDA during the entire master-generated 9th
clock pulse if the previous byte is successfully received.
Monitoring ACK allows for detection of unsuccessful
data transfers. An unsuccessful data transfer occurs if a
receiving device is busy or if a system fault has occurred.
In the event of an unsuccessful data transfer, the bus
master will retry communication.
t
HD:STA
INVALID START/STOP PULSE PAIRINGS-ALL WILL BE RECOGNIZED AS STARTS
2
C, Low-Voltage Linear
P
ACKNOWLEDGE (A)
S
S
P
Figure
STOP CONDITION
t
SU:STD
P
MAX5395
(P)
2
I
S
2
C sequence will
4. The MAX5395
C Acknowledge
t
BUF
P
START CONDITION
Figure
(S)
11
3.