MAX1254AEUE+ Maxim Integrated, MAX1254AEUE+ Datasheet - Page 23

• Manufacturer Part Number: MAX1254AEUE+
• Description: Analog to Digital Converters - ADC
• Manufacturer: Maxim Integrated

Specifications of MAX1254AEUE+

• Number Of Channels: 10
• Architecture: SAR
• Conversion Rate: 94 KSPs
• Resolution: 12 bit
• Input Type: Single-Ended/Differential
• Interface Type: Serial
• Operating Supply Voltage: 4.5 V to 5.5 V
• Number Of Converters: 1
• Voltage Reference: Internal 4.096 V or External

ential, or unipolar/bipolar), carry out the following steps
to execute a manual conversion. See Figure 9 for man-
ual conversion timing:
1) Disable autoscan (set up register scan mode bit to
2) Pull CS low.
3) Initiate a conversion by issuing a Manually Triggered
4) Pull CS high to start the conversion.
5) Maintain a logic high on CS to allow for reference
6) Pull CS low.
7) Issue a Read Current Data Register for Selected-
Every voltage measurement (internal V
input channel) requires 10.6µs to complete. If the inter-
nal reference needs to power up (reference mode =
01), an additional 40µs is required every time the
MAX1253/MAX1254 come out of automatic shutdown
mode after a sample wait period greater than 80µs.
This internal acquisition channel samples and converts
the supply voltage, V
Figure 9. Manual Conversion Timing Without Reading Data
with Internal Temperature Sensor and V
zero), if necessary.
Conversion command (0000, followed by the
address bits of the channel to be converted).
power-up (if the reference mode requires it) and
conversion time.
Channel command (0010, followed by the same
address of the channel in the Manually Triggered
Conversion command).
DOUT
SCLK
DIN
Stand-Alone, 10-Channel, 12-Bit System Monitors
CS
C3
C2
______________________________________________________________________________________
DD
C1 C0
.
Voltage Measurements
A3
A2 A1
Monitoring V
A0
DD
or external
DD
t
PU+CONV
V
with the following equation:
The reference voltage must be larger than 1/2V
the operation to work properly. V
10.6µs (typ) per measurement.
The MAX1253/MAX1254 perform temperature measure-
ment by measuring the voltage across a diode-con-
nected transistor at two different current levels. The
following equation illustrates the algorithm used for
temperature calculations:
where:
V
(I
V
(I
q = charge of electron = 1.602
k = Boltzman constant = 1.38
n = ideality factor (slightly greater than 1)
DD
HIGH
HIGH
LOW
LOW
V
DD
value can be calculated from the digitized data
temperature
)
)
= sensor-diode voltage with low current flowing
=
= sensor-diode voltage with high current flowing
2
x current data register content x
(
C3
=
(
_
Temperature Measurement
V
C2
HIGH
C1 C0
_
-
V
✕
LOW
DD
A3
✕
10
DD
10
-23
A2 A1
)
_
-19
x
monitoring requires
J/K
n x ln
Monitor
coulombs
A0



q
k
)
I
I
LOW
High



V
4096
DD
REF



for



23