MAX1455AAE Maxim Integrated Products, MAX1455AAE Datasheet - Page 13

• Manufacturer Part Number: MAX1455AAE
• Description: Board Mount Temperature Sensors Automotive Sensor Signal Conditioner
• Manufacturer: Maxim Integrated Products

Specifications of MAX1455AAE

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

DIO is configured as a digital output by writing a Read
IRS (RDIRS) command (5 hex) to the CRIL location. On
receipt of this command, the MAX1455 outputs a byte
of data, the contents of which are determined by the
IRS pointer (IRSP[3:0]) value at location IRSA[3:0] =
8hex. The data is output as a single byte, framed by a
start bit and a stop bit. Table 11 lists the data returned
for each IRSP address value.
Once the RDIRS command has been sent, all connec-
tions to DIO must be three-stated to allow the MAX1455
to drive the DIO line. Following receipt of the RDIRS
command, the MAX1455 drives DIO high after 1 byte
time. The MAX1455 holds DIO high for a single bit time
and then asserts a start bit (drives DIO low). The start
bit is then followed by the data byte and a stop bit.
Immediately following transmission of the stop bit, the
MAX1455 three-states DIO, releasing the line. The
MAX1455 is then ready to receive the next command
sequence 1 byte time after release of DIO.
Table 7. Input Referred Offset (IRO[2:0])
IRO SIGN, IRO[2:0]
1,111
1,110
1,101
1,100
1,011
1,010
1,001
1,000
0,000
0,001
0,010
0,011
0,100
0,101
0,110
0,111
______________________________________________________________________________________
Low-Cost Automotive Sensor Signal
Serial Digital Output
CORRECTION AS % OF V
INPUT-REFERRED OFFSET
+1.25
+1.08
+0.90
+0.72
+0.54
+0.36
+0.18
-0.18
-0.36
-0.54
-0.72
-0.90
-1.08
-1.25
0
0
Note that there are time intervals before and after the
MAX1455 sends the data byte when all devices on the
DIO line are three-stated. It is recommended that a
weak pullup resistor be applied to the DIO line during
these time intervals to prevent unwanted transitions
(Figure 4). In applications where DIO and analog out-
put (OUT) are not connected, a pullup resistor should
be permanently connected to DIO. If the MAX1455 DIO
and analog outputs are connected, then do not load
this common line during analog measurements. In this
situation, perform the following sequence:
1) Connect a pullup resistor to the DIO/OUT line,
2) Send the RDIRS command.
3) Three-state the user connection (set to high imped-
4) Receive data from the MAX1455.
5) Activate the user connection (pull DIO/OUT line high).
6) Release the pullup resistor.
preferably with a relay.
ance).
DD
I N PU T - R EF ER R ED O F F SET , CO R R EC T IO N
A T V
Conditioner
DD
= 5VD C IN m V
+63
+54
+45
+36
+27
+18
-18
-27
-36
-45
-54
-63
+9
-9
0
0
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