10-Bit Digital Temperature Sensor (AD7416) and
Four Single-Channel ADCs (AD7417/AD7418)
AD7416/AD7417/AD7418
FEATURES
10-Bit ADC with 15 s and 30 s Conversion Times
Single and Four Single-Ended Analog Input Channels
On-Chip Temperature Sensor: –40 C to +125 C
On-Chip Track-and-Hold
Overtemperature Indicator
Automatic Power-Down at the End of a Conversion
Wide Operating Supply Range: 2.7 V to 5.5 V
I
2
C
®
Compatible Serial Interface
Selectable Serial Bus Address Allows Connection of up
to Eight AD7416/AD7417s to a Single Bus
AD7416 Is a Superior Replacement for LM75
APPLICATIONS
Data Acquisition with Ambient Temperature Monitoring
Industrial Process Control
Automotive
Battery-Charging Applications
Personal Computers
GENERAL DESCRIPTION
A0
A1
A2
SERIAL BUS
INTERFACE
FUNCTIONAL BLOCK DIAGRAMS
BAND GAP
TEMPERATURE
SENSOR
10-BIT
ANALOG-DIGITAL
CONVERTER
TEMPERATURE
VALUE
REGISTER
AD7416
ADDRESS
POINTER
REGISTER
T
OTI
SETPOINT
REGISTER
T
HYST
SETPOINT
REGISTER
CONFIGURATION
REGISTER
SETPOINT
COMPARATOR
V
DD
FAULT
QUEUE
COUNTER
OTI
GND
SDA
SCL
REF
IN
V
DD
The AD7417 and AD7418 are 10-bit, 4-channel and single-
channel ADCs with an on-chip temperature sensor that
can operate from a single 2.7 V to 5.5 V power supply. The
devices contain a 15
µs
successive approximation converter, a
5-channel multiplexer, a temperature sensor, a clock oscilla-
tor, a track-and-hold, and a reference (2.5 V). The AD7416
is a temperature-monitoring only device in an 8-lead package.
The temperature sensor on the parts can be accessed via multi-
plexer Channel 0. When Channel 0 is selected and a conversion
is initiated, the resulting ADC code at the end of the conversion
gives a measurement of the ambient temperature (±1°C @ 25°C).
On-chip registers can be programmed with high and low tem-
perature limits, and an open-drain overtemperature indicator
(OTI) output is provided, which becomes active when a pro-
grammed limit is exceeded.
A configuration register allows programming of the sense of the
OTI output (active high or active low) and its operating mode
(comparator or interrupt). A programmable fault queue counter
allows the number of out-of-limit measurements that must occur
before triggering the OTI output to be set to prevent spurious
triggering of the OTI output in noisy environments.
(continued on page 7)
OVERTEMP REG B
TEMP
SENSOR
REF
2.5V
A
IN1
A
IN2
A
IN3
A
IN4
V
BALANCE
MUX
SAMPLING
CAPACITOR
+
CHARGE
DISTRIBUTION
DAC
A>B
A
DATA OUT
OTI
CLOCK
CONTROL
LOGIC
SCL
I
2
C
INTERFACE
SDA
AD7417
NC NC GND
NC = NO CONNECT
CONVST
A0
A1
A2
V
DD
REF
IN
OVERTEMP REG B
A>B
A
OTI
TEMP
SENSOR
REF
2.5V
CHARGE
DISTRIBUTION
DAC
DATA OUT
A
IN1
MUX
CLOCK
SAMPLING
CAPACITOR
+
CONTROL
LOGIC
I
2
C
INTERFACE
SCL
SDA
REV. G
GND
V
BALANCE
CONVST
AD7418
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