SPI/I
2
C Compatible, Temperature Sensor,
4-Channel ADC and Quad Voltage Output DAC
ADT7518
Rev. A
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Fax: 781.326.8703
?2004 Analog Devices, Inc. All rights reserved.
FEATURES
Four 8-bit DACs
Buffered voltage output
Guaranteed monotonic by design over all codes
10-bit temperature-to-digital converter
10-bit 4-channel ADC
DC input bandwidth
Input range: 0 V to 2.25 V
Temperature range: 40癈 to +120癈
Temperature sensor accuracy of typ: ?.5癈
Supply range: 2.7 V to 5.5 V
DAC output range: 0 V to 2 V
REF
Power-down current: 1 礎
Internal 2.25 V
REF
option
Double-buffered input logic
Buffered reference input
Power-on reset to 0 V DAC output
Simultaneous update of outputs (LDAC
function)
On-chip rail-to-rail output buffer amplifier
SPI
?/DIV>
, I
2
C
?/DIV>
, QSPI", MICROWIRE", and DSP-compatible
4-wire serial interface
SMBus packet error checking (PEC)-compatible
16-lead QSOP package
APPLICATIONS
Portable battery-powered instruments
Personal computers
Smart battery chargers
Telecommunications systems
Electronic text equipment
Domestic appliances
Process control
PIN CONFIGURATION
ADT7518
TOP VIEW
(Not to Scale)
V
OUT
-B   1
V
OUT
-C
16
V
OUT
-A   2
V
OUT
-D
15
V
REF
-IN   3
AIN4
14
CS   4
SCL/SCLK
13
GND   5
SDA/DIN
12
V
DD
6
DOUT/ADD
11
D+/AIN1   7
INT/INT
10
D/AIN2   8
LDAC/AIN3
9
Figure 1.
GENERAL DESCRIPTION
The ADT7518 combines a 10-bit temperature-to-digital
converter, a 10-bit 4-channel ADC, and a quad 8-bit DAC, in a
16-lead QSOP package. The part also includes a band gap
temperature sensor and a 10-bit ADC to monitor and digitize
the temperature reading to a resolution of 0.25癈.
The ADT7518 operates from a single 2.7 V to 5.5 V supply. The
input voltage range on the ADC channels is 0 V to 2.25 V, and
the input bandwidth is dc. The reference for the ADC channels
is derived internally. The output voltage of the DAC ranges
from 0 V to V
DD
, with an output voltage settling time of 7 ms
typical.
The ADT7518 provides two serial interface options: a 4-wire
serial interface that is compatible with SPI, QSPI, MICROWIRE,
and DSP interface standards, and a 2-wire SMBus/I
2
C interface.
It features a standby mode that is controlled through the serial
interface.
The reference for the four DACs is derived either internally or
from a reference pin. The outputs of all DACs may be updated
simultaneously using the software LDAC function or the exter-
nal LDAC
pin. The ADT7518 incorporates a power-on reset
circuit, which ensures that the DAC output powers up to 0 V
and remains there until a valid write takes place.
The ADT7518s wide supply voltage range, low supply current,
and SPI-/I
2
C-compatible interface make it ideal for a variety of
applications, including personal computers, office equipment,
and domestic appliances.
It is recommended that new designs use the ADT7519 rather
than the ADT7518. The ADT7518s internal and external temp-
erature accuracy spec is only valid when not using the internal
reference for the on-chip DAC. The ADT7519 does not have
this limitation.