10-Bit Digital Temperature Sensor
(AD7416) and Four Single-Channel ADCs
AD7416/AD7417/AD7418
FEATURES
10-bit ADC with 15 μs and 30 μs conversion times
Single and 4 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 8
AD7416/AD7417 devices to a single bus
AD7416 is a superior replacement for LM75
A0
7
A1
6
FUNCTIONAL BLOCK DIAGRAMS
BAND GAP
TEMPERATURE
SENSOR
10-BIT
ANALOG-TO-DIGITAL
CONVERTER
TEMPERATURE
VALUE
REGISTER
ADDRESS
POINTER
REGISTER
T
OTI
SETPOINT
REGISTER
T
HYST
SETPOINT
REGISTER
CONFIGURATION
REGISTER
SERIAL BUS
INTERFACE
FAULT
QUEUE
COUNTER
AD7416
SETPOINT
COMPARATOR
8
V
DD
3
OTI
4
GND
1
SDA
2
SCL
01126-001
APPLICATIONS
Data acquisition with ambient temperature monitoring
Industrial process control
Automotive
Battery-charging applications
Personal computers
A2
5
Figure 1. AD7416
REF
IN
5
V
DD
14
T
OTI
SETPOINT
B
REGISTER
TEMP
SENSOR
REF
2.5V
A
IN1 7
A
IN2 8
A
IN3 9
A
IN4 10
V
BALANCE
1
16
6
15
13
A>B
A
4
OTI
GENERAL DESCRIPTION
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 oscillator, 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 multip-
lexer 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 tempera-
ture limits, and an open-drain overtemperature indicator (OTI)
output is provided, which becomes active when a programmed
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.
CHARGE
DISTRIBUTION
DAC
DATA OUT
MUX
SAMPLING
CAPACITOR
I
2
C
CLOCK CONTROL
LOGIC
INTERFACE
3
SCL
SDA
2
AD7417
12
11
01126-002
NC
NC
GND
CONVST
A0
A1
A2
NC = NO CONNECT
Figure 2. AD7417
V
DD
7
REF
IN
6
T
OTI
SETPOINT B
REGISTER
TEMP
SENSOR
REF
2.5V
A
IN 5
MUX
SAMPLING
CAPACITOR
CHARGE
DISTRIBUTION
DAC
A>B
A
DATA OUT
3
OTI
I
2
C
CLOCK CONTROL
LOGIC
INTERFACE
2
SCL
SDA
1
AD7418
4
8
01126-003
V
BALANCE
GND
CONVST
Figure 3. AD7418
Rev. I
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