MAX1455AAE-T Maxim Integrated Products, MAX1455AAE-T Datasheet - Page 17

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

Specifications of MAX1455AAE-T

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

ATIM function uses the communication baud rate as a
timing basis. See Table 14 for details. At the end of the
period determined by ATIM[3:0], the analog signal is
disconnected from the analog output and OUT
resumes a three-state condition. The MAX1455 can
receive further commands on DIO 1 byte after resum-
ing a three-state condition on OUT. Figure 6 shows the
timing of this scheme.
Table 11. IRSP Decode
Table 12. CLK Code (3MSBs of
Configuration Register)
1010-1111
IRSP[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
CLK CODE (BIN)
011
010
001
000
111
110
101
DHR[7:0]
DHR[15:8]
IEEA[7:4], ICRA[3:0] concatenated
CRIL[3:0], IRSP[3:0] concatenated
ALOC[3:0], ATIM[3:0] concatenated
IEEA[7:0] EEPROM address byte
IEED[7:0] EEPROM data byte
Temp-Index[7:0]
BitClock[7:0]
Reserved. Internal flash test data.
11001010 (CAhex). This can be used to
test communication.
______________________________________________________________________________________
RETURNED VALUE
Low-Cost Automotive Sensor Signal
CLOCK ADJUSTMENT (%)
+27
+18
-18
-27
+9
-9
0
The MAX1455 DIO is three-state for the duration that
the analog output is active. This is to allow OUT and
DIO to be connected in parallel. When DIO and OUT
are connected in parallel, the host computer must also
three-state its communications connection to the
MAX1455. This requirement produces periods when all
connections to the DIO are three-stated simultaneously,
making it necessary to have a weak pullup resistor
applied to DIO during these periods.
A continuous output mode is available for the analog
output and is selected by setting ATIM[3:0] to Fhex.
This mode may only be used when DIO and OUT are
separate. While in this mode and following receipt of
the RdAlg command, or any other command, DIO
three-states for a period of 32,769 byte times. Once this
period has elapsed, DIO enters receive mode and
accepts further command inputs. The analog output is
always active while in continuous mode.
Note: The internal analog signals are not buffered
when connected to OUT. Any loading of OUT while one
of these internal signals is being measured is likely to
produce measurement errors. Do not load OUT when
reading internal signals such as BDR, FSOTC, etc.
A selection of examples of the command sequences for
various functions within the MAX1455 follows.
Example 1. Change the baud rate setting and check
communications. If the communication with the
MAX1455 is lost due to a system baud rate change
before sending the reinitialization command, apply a
power reset to guarantee the initialization condition.
COMMAND
FFhex
01hex
F8hex
59hex
Communication Command Examples
Reinitialize part ready for baud rate learning.
Change system baud rate to new value.
Learn baud rate.
Load 15 (Fhex) to IRSP[3:0] register.
Read IRS.
Host computer must be ready to receive
data on the serial line within 1 (baud rate)
byte time of sending the Read IRS
command. The MAX1455 returns CAhex.
(IRSP values of 10 to 15 are configured to
return CAhex for communication checking
purposes.)
Conditioner
ACTION
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