AD7816AR-REEL7 ,Temperature Sensor: 10-Bit ADC, Temperature Monitoring Only in an SOIC/µSOIC PackageFEATURES FUNCTIONAL BLOCK DIAGRAM10-Bit ADC with 9 s Conversion TimeVREFDDINOne (AD7818) and Four ..
AD7817AR ,Single- and 4-Channel, 9 us, 10-Bit ADCs with On-Chip Temperature SensorSPECIFICATIONSDD INParameter A Version *B Version *S Version Units Test Conditions/CommentsDYNAMIC ..
AD7817AR ,Single- and 4-Channel, 9 us, 10-Bit ADCs with On-Chip Temperature SensorFEATURES10-Bit ADC with 9 ms Conversion TimeVREFDDINOne (AD7818) and Four (AD7817) Single-Ended Ana ..
AD7817ARU ,Single- and 4-Channel, 9 us, 10-Bit ADCs with On-Chip Temperature SensorSPECIFICATIONSDD INParameter A Version *B Version *S Version Units Test Conditions/CommentsDYNAMIC ..
AD7817ARUZ-REEL7 , Dual, Low Power CMOS, Analog Front End with DSP Microcomputer
AD7817ARZ-REEL7 , Dual, Low Power CMOS, Analog Front End with DSP Microcomputer
ADM207ARS ,0.1 uF, +5 V Powered CMOS RS-232 Drivers/ReceiversAPPLICATIONS8 R1 9 R1R1OUT INComputers5 R2 4 R2R2 INPeripherals OUTRS-232TTL/CMOS26 R3 27 R3Modems ..
ADM207ARS ,0.1 uF, +5 V Powered CMOS RS-232 Drivers/Receiversapplications where ±12 V is not available. The ADM205,All members of the ADM2xx family, except the ..
ADM207EAN ,EMI/EMC Compliant, +-15 kV ESD Protected, RS-232 Line Drivers/ReceiversAPPLICATIONSCMOS EIA/TIA-23226 R3 27 R3R3Laptop Computers OUT INOUTPUTSINPUTS**Notebook Computers22 ..
ADM207EAR ,EMI/EMC Compliant, +-15 kV ESD Protected, RS-232 Line Drivers/ReceiversGENERAL DESCRIPTIONNOTES:The ADM2xxE is a family of robust RS-232 and V.28 interface * INTERNAL 40 ..
ADM207EAR-REEL , EMI/EMC-Compliant, ±15 kV ESDProtected, RS-232 Line Drivers/Receivers
ADM207EARS ,EMI/EMC Compliant, +-15 kV ESD Protected, RS-232 Line Drivers/Receiversspecifications T to T unless otherwise noted.)CC MIN MAXParameter Min Typ Max Units Test Conditions ..
AD7816ACHIPS-AD7816ARM-REEL7-AD7816AR-REEL-AD7816AR-REEL7
Temperature Sensor: 10-Bit ADC, Temperature Monitoring Only in an SOIC/µSOIC Package
REV.C
Single- and 4-Channel, 9 �s, 10-Bit ADCs
with On-Chip Temperature Sensor
FUNCTIONAL BLOCK DIAGRAMFEATURES
10-Bit ADC with 9 �s Conversion Time
One (AD7818) and Four (AD7817) Single-Ended Analog
Input Channels
The AD7816 Is a Temperature Measurement Only Device
On-Chip Temperature Sensor
Resolution of 0.25�C�2�C Error from –40�C to +85�C
–55�C to +125�C Operating Range
Wide Operating Supply Range
2.7 V to 5.5 V
Inherent Track-and-Hold Functionality
On-Chip Reference (2.5 V � 1%)
Overtemperature Indicator
Automatic Power-Down at the End of a Conversion
Low Power Operation
4 �W at a Throughput Rate of 10 SPS
40 �W at a Throughput Rate of 1 kSPS
400 �W at a Throughput Rate of 10 kSPS
Flexible Serial Interface
APPLICATIONS
Ambient Temperature Monitoring (AD7816)
Thermostat and Fan Control
High Speed Microprocessor
Temperature Measurement and Control
Data Acquisition Systems with Ambient Temperature
Monitoring (AD7817 and AD7818)
Industrial Process Control
Automotive
Battery Charging Applications
GENERAL DESCRIPTIONThe AD7818 and AD7817 are 10-bit, single- and 4-channel
A/D converters with on-chip temperature sensor that can oper-
ate from a single 2.7 V to 5.5 V power supply. Each part con-
tains a 9 µs successive-approximation converter based around
a capacitor DAC, an on-chip temperature sensor with an accu-
racy of �2°C, an on-chip clock oscillator, inherent track-and-
hold functionality and an on-chip reference (2.5 V). The
AD7816 is a temperature monitoring only device in a SOIC/
MSOP package.
The on-chip temperature sensor of the AD7817 and AD7818
can be accessed via 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
with a resolution of �0.25°C. See Temperature Measurement
section of this data sheet.
The AD7816, AD7817, and AD7818 have a flexible serial
interface that allows easy interfacing to most microcontrollers.
The interface is compatible with the Intel 8051, Motorola
SPI® and QSPI™ protocols and National Semiconductors
MICROWIRE™ protocol. For more information refer to the
Serial Interface section of this data sheet.
The AD7817 is available in a narrow body 0.15" 16-lead small
outline IC (SOIC), in a 16-lead, thin shrink small outline pack-
age (TSSOP), while the AD7816/AD7818 come in an 8-lead
small outline IC (SOIC) and an 8-lead microsmall outline IC
(MSOP).
PRODUCT HIGHLIGHTSThe devices have an on-chip temperature sensor that allows an
accurate measurement of the ambient temperature to be
made. The measurable temperature range is –55°C to +125°C.An overtemperature indicator is implemented by carrying out a
digital comparison of the ADC code for Channel 0 (tempera-
ture sensor) with the contents of the on-chip overtemperature
register. The overtemperature indicator pin goes logic low when
a predetermined temperature is exceeded.The automatic power-down feature enables the AD7816,
AD7817, and AD7818 to achieve superior power perfor-
mance at slower throughput rates, e.g., 40 µW at 1 kSPS
throughput rate.
DOUT
SCLK
RD/WR
CONVSTAGNDOTI
REFINVDD
DIN
DGNDBUSY
VIN1
VIN2
VIN3
VIN4
AD7816/AD7817/AD7818TEMPERATURE SENSOR
REFERENCE INPUT
POWER REQUIREMENTS
AD7817–SPECIFICATIONS1
(VDD = 2.7 V to 5.5 V, GND = 0V, REFIN = 2.5V unless otherwise noted)
AD7816/AD7817/AD7818TEMPERATURE SENSOR
AD7816/AD78186–SPECIFICATIONS1(VDD = 2.7 V to 5.5 V, GND = 0 V, REFIN = 2.5 V unless
otherwise noted)
AD7816/AD7817/AD7818–SPECIFICATIONSANALOG INPUTS
LOGIC OUTPUTS
NOTES
*B and S Versions apply to AD7817 only. For operating temperature ranges, see Ordering Guide.AD7816 and AD7817 temperature sensors specified with external 2.5 V reference, AD7818 specified with on-chip reference. All other specifications with external
and on-chip reference (2.5 V). For VDD = 2.7 V, TA = 85°C max and temperature sensor measurement error = �3°C.See Terminology.The accuracy of the temperature sensor is affected by reference tolerance. The relationship between the two is explained in the section titled Temperature Measure-
ment Error Due to Reference Error.Sample tested during initial release and after any redesign or process change that may affect this parameter.On-chip reference shuts down when external reference is applied.All specifications are typical for AD7818 at temperatures above 85°C and with VDD greater than 3.6 V.Refers to the input current when the part is not converting. Primarily due to reverse leakage current in the ESD protection diodes.
Specifications subject to change without notice.
Figure 1.AD7816 Functional Block Diagram
DIN/OUT
SCLK
RD/WR
CONVSTAGNDOTI
VDD
VIN1Figure 2.AD7818 Functional Block Diagram
AD7816/AD7817/AD7818
TIMING CHARACTERISTICS1, 2t11
t13
t15
t16
NOTESSample tested during initial release and after any redesign or process change that may affect this parameter. All input signals are measured with tr = tf = 1ns (10% to
90% of 5 V) and timed from a voltage level of 1.6V.See Figures 16, 17, 20 and 21.These figures are measured with the load circuit of Figure 3. They are defined as the time required for DOUT to cross 0.8 V or 2.4 V for VDD = 5 V � 10% and 0.4 V
or 2 V for VDD = 3 V � 10%, as quoted on the specifications page of this data sheet.These times are derived from the measured time taken by the data outputs to change 0.5V when loaded with the circuit of Figure 3. The measured number is then
extrapolated back to remove the effects of charging or discharging the 50 pF capacitor. This means that the times quoted in the timing characteristics are the true bus
relinquish times of the part and as such are independent of external bus loading capacitances.
Specifications subject to change without notice.
Figure 3.Load Circuit for Access Time and Bus Relinquish Time
(VDD = 2.7 V to 5.5 V, GND = 0V, REFIN = 2.5V. All specifications TMIN to TMAX unless
otherwise noted)
AD7816/AD7817/AD7818
ABSOLUTE MAXIMUM RATINGS1(TA = 25°C unless otherwise noted)
VDD to AGND . . . . . . . . . . . . . . . . . . . . . . . . . –0.3V to +7V
VDD to DGND . . . . . . . . . . . . . . . . . . . . . . . . . –0.3V to +7V
Analog Input Voltage to AGND
VIN1 to VIN4 . . . . . . . . . . . . . . . . . . . –0.3 V to VDD + 0.3 V
Reference Input Voltage to AGND2 . . . –0.3 V to VDD + 0.3V
Digital Input Voltage to DGND . . . . . . –0.3 V to VDD + 0.3 V
Digital Output Voltage to DGND . . . . . –0.3 V to VDD + 0.3 V
Storage Temperature Range . . . . . . . . . . . . .–65°C to +150°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . .150°C
TSSOP, Power Dissipation . . . . . . . . . . . . . . . . . . . . 450 mW
θJA Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 120°C/W
Lead Temperature, Soldering . . . . . . . . . . . . . . . . . .260°C
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . .215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . .220°C
16-Lead SOIC Package, Power Dissipation . . . . . . . . 450 mW
θJA Thermal Impedance . . . . . . . . . . . . . . . . . . . . .100°C/W
Lead Temperature, Soldering
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . 215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . 220°C
8-Lead SOIC Package, Power Dissipation . . . . . . . . . .450 mW
θJA Thermal Impedance . . . . . . . . . . . . . . . . . . . . .157°C/W
Lead Temperature, Soldering
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . 215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . 220°C
µSOIC Package, Power Dissipation . . . . . . . . . . . . . . 450 mW
θJA Thermal Impedance . . . . . . . . . . . . . . . . . . . . .206°C/W
Lead Temperature, Soldering
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . 215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . 220°C
NOTESStresses above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those listed in the operational sections
of this specification is not implied. Exposure to absolute maximum rating condi-
tions for extended periods may affect device reliability.If the Reference Input Voltage is likely to exceed VDD by more than 0.3V (e.g.,
during power-up) and the reference is capable of supplying 30mA or more, it is
recommended to use a clamping diode between the REFIN pin and VDD pin. The
diagram below shows how the diode should be connected.
CAUTIONESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000V readily
accumulate on the human body and test equipment and can discharge without detection. Although the
AD7816/AD7817/AD7818 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions
are recommended to avoid performance degradation or loss of functionality.
ORDERING GUIDE*Z = Pb free part
AD7816/AD7817/AD7818
AD7817 PIN FUNCTION DESCRIPTIONSPIN CONFIGURATION
SOIC/TSSOP
PIN CONFIGURATIONS
SOIC/MSOP (AD7816)
SOIC/MSOP (AD7818)
TERMINOLOGY
Signal-to-(Noise + Distortion) RatioThis is the measured ratio of signal-to-(noise + distortion) at the
output of the A/D converter. The signal is the rms amplitude of
the fundamental. Noise is the rms sum of all nonfundamental
signals up to half the sampling frequency (fS/2), excluding dc.
The ratio is dependent upon the number of quantization levels in
the digitization process; the more levels, the smaller the quantiza-
tion noise. The theoretical signal-to-(noise + distortion) ratio for
an ideal N-bit converter with a sine wave input is given by:
Total Harmonic DistortionTotal harmonic distortion (THD) is the ratio of the rms sum of
harmonics to the fundamental. For the AD7891 it is defined as:
where V1 is the rms amplitude of the fundamental and V2, V3,
V4, V5, and V6 are the rms amplitudes of the second through the
sixth harmonics.
Peak Harmonic or Spurious NoisePeak harmonic or spurious noise is defined as the ratio of the
rms value of the next largest component in the ADC output
spectrum (up to fS/2 and excluding dc) to the rms value of the
fundamental. Normally, the value of this specification is deter-
mined by the largest harmonic in the spectrum, but for parts
where the harmonics are buried in the noise floor, it will be a
noise peak.
Intermodulation DistortionWith inputs consisting of sine waves at two frequencies, fa and
fb, any active device with nonlinearities will create distortion
products at sum and difference frequencies of mfa � nfb where
m, n = 0, 1, 2, 3, etc. Intermodulation terms are those for which
neither m nor n are equal to zero. For example, the second
order terms include (fa + fb) and (fa – fb), while the third order
terms include (2fa + fb), (2fa – fb), (fa + 2fb) and (fa – 2fb).
AD7816 AND AD7818 PIN FUNCTION DESCRIPTIONS
AD7816/AD7817/AD7818The AD7816, AD7817, and AD7818 are tested using the CCIF
standard where two input frequencies near the top end of the
input bandwidth are used. In this case, the second and third
order terms are of different significance. The second order terms
are usually distanced in frequency from the original sine waves
while the third order terms are usually at a frequency close to
the input frequencies. As a result, the second and third order
terms are specified separately. The calculation of the intermodu-
lation distortion is as per the THD specification where it is the
ratio of the rms sum of the individual distortion products to the
rms amplitude of the fundamental expressed in dBs.
Channel-to-Channel IsolationChannel-to-channel isolation is a measure of the level of
crosstalk between channels. It is measured by applying a full-
scale 20kHz sine wave signal to one input channel and deter-
mining how much that signal is attenuated in each of the other
channels. The figure given is the worst case across all four
channels.
Relative AccuracyRelative accuracy or endpoint nonlinearity is the maximum
deviation from a straight line passing through the endpoints of
the ADC transfer function.
Differential NonlinearityThis is the difference between the measured and the ideal
1LSB change between any two adjacent codes in the ADC.
Offset ErrorThis is the deviation of the first code transition (0000...000)
to (0000...001) from the ideal, i.e., AGND + 1 LSB.
Offset Error MatchThis is the difference in Offset Error between any two channels.
Gain ErrorThis is the deviation of the last code transition (1111...110) to
(1111...111) from the ideal, i.e., VREF – 1 LSB, after the
offset error has been adjusted out.
Gain Error MatchThis is the difference in Gain Error between any two channels.
Track/Hold Acquisition TimeTrack/hold acquisition time is the time required for the output
of the track/hold amplifier to reach its final value, within
�1/2 LSB, after the end of conversion (the point at which the
track/hold returns to track mode). It also applies to situations
where a change in the selected input channel takes place or
where there is a step input change on the input voltage applied
to the selected VIN input of the AD7817 or AD7818. It means
that the user must wait for the duration of the track/hold acqui-
sition time after the end of conversion or after a channel change/
step input change to VIN before starting another conversion, to
ensure that the part operates to specification.
CONTROL BYTEThe AD7816, AD7817, and AD7818 contain two on-chip regis-
ters, the Address Register and the Overtemperature Register.
These registers can be accessed by carrying out an 8-bit serial
write operation to the devices. The 8-bit word or control byte
written to the AD7816, AD7817, and AD7818 is transferred to
Address RegisterIf the five MSBs of the control byte are logic zero, the three
LSBs of the control byte are transferred to the Address Regis-
ter—see Figure 4. The Address Register is a 3-bit-wide register
used to select the analog input channel on which to carry out a
conversion. It is also used to select the temperature sensor,
which has the address 000. Table I shows the selection. The
Internal Reference selection connects the input of the ADC to a
band gap reference. When this selection is made and a conver-
sion is initiated, the ADC output should be approximately mid-
scale. After power-up the default channel selection is DB2 = DB1
= DB0 = 0 (Temperature Sensor).
Table I.Channel Selection
Overtemperature RegisterIf any of the five MSBs of the control byte are logic one, then
the entire eight bits of the control byte are transferred to the
Overtemperature Register—see Figure 4. At the end of a tem-
perature conversion a digital comparison is carried out between
the 8 MSBs of the temperature conversion result (10 bits) and
the contents of the Overtemperature Register (8 bits). If the result
of the temperature conversion is greater that the contents of the
Overtemperature Register (OTR), then the Overtemperature
Indicator (OTI) goes logic low. The resolution of the OTR is
1°C. The lowest temperature that can be written to the OTR is –
95°C and the highest is +152°C—see Figure 5. However, the
usable temperature range of the temperature sensor is –55°C to
+125°C. Figure 5 shows the OTR and how to set TALARM (the
temperature at which the OTI goes low).
OTR (Dec) = TALARM (°C) + 103°C
For example, to set TALARM to 50°C, OTR = 50 + 103 = 153
Dec or 10011001 Bin. If the result of a temperature conversion
exceeds 50°C then OTI will go logic low. The OTI logic output
is reset high at the end of a serial read operation or if a new
temperature measurement is lower than TALARM. The default
power on TALARM is 50°C.
