AD7417_15 Datasheet, PDF (1/24 Pages) Analog Devices – 10-Bit Digital Temperature Sensor

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
I²C-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
APPLICATIONS
Data acquisition with ambient temperature monitoring
Industrial process control
Automotive
Battery-charging applications
Personal computers
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.
FUNCTIONAL BLOCK DIAGRAMS
BAND GAP
TEMPERATURE
SENSOR
10-BIT
ANALOG-TO-DIGITAL
CONVERTER
AD7416
ADDRESS
POINTER
REGISTER
A0 7
A1 6
A2 5
TEMPERATURE
VALUE
REGISTER
T_OTI SETPOINT
REGISTER
T_HYST SETPOINT
REGISTER
CONFIGURATION
REGISTER
SETPOINT
COMPARATOR
FAULT
QUEUE
COUNTER
SERIAL BUS
INTERFACE
TEMP
SENSOR
Figure 1. AD7416
REF_IN
5
V_DD
14
REF
2.5V
T_OTI SETPOINT _B
REGISTER
CHARGE
DISTRIBUTION
DAC
A>B
A
DATA OUT
A_IN1 7
A_IN2 8
A_IN3 9
A_IN4 10
MUX
1 16
NC NC
CLOCK
CONTROL
LOGIC
I²C
INTERFACE
SAMPLING
CAPACITOR
V_BALANCE
6
GND
15
CONVST
AD7417
13
12
11
A0 A1 A2
NC = NO CONNECT
Figure 2. AD7417
V_DD
7
REF_IN
6
TEMP
SENSOR
REF
2.5V
T_OTI SETPOINT _B
REGISTER
CHARGE
DISTRIBUTION
DAC
A>B
A
DATA OUT
A_IN 5
MUX
CLOCK
CONTROL
LOGIC
I²C
INTERFACE
SAMPLING
CAPACITOR
V_BALANCE
4
GND
8
CONVST
Figure 3. AD7418
AD7418
8 V_DD
3 OTI
4 GND
1 SDA
2 SCL
4 OTI
3 SCL
2 SDA
3 OTI
2 SCL
1 SDA
Rev. I
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