SPI/I2C Compatible, Temperature Sensor,
4-Channel ADC and Quad Voltage Output DAC
ADT7518
FEATURES
APPLICATIONS
Four 8-bit DACs
Portable battery-powered instruments
Buffered voltage output
Personal computers
Guaranteed monotonic by design over all codes
10-bit temperature-to-digital converter
10-bit 4-channel ADC
Smart battery chargers
Telecommunications systems
Electronic text equipment
Domestic appliances
DC input bandwidth
Input range: 0 V to 2.25 V
Process control
Temperature range: –40°C to +120°C
Temperature sensor accuracy of typ: 0.5°C
Supply range: 2.7 V to 5.5 V
PIN CONFIGURATION
DAC output range: 0 V to 2 VREF
Power-down current: 1 µA
Internal 2.25 VREF 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
V
V
-B
1
2
3
4
5
6
7
8
16
15
V
V
-C
OUT
OUT
OUT
OUT
-A
-D
V
-IN
14 AIN4
REF
ADT7518
TOP VIEW
CS
13 SCL/SCLK
12 SDA/DIN
11 DOUT/ADD
10 INT/INT
GND
(Not to Scale)
V
DD
D+/AIN1
D–/AIN2
9
LDAC/AIN3
Figure 1.
SPI®, I2C®, QSPI™, MICROWIRE™, and DSP-compatible
4-wire serial interface
SMBus packet error checking (PEC)-compatible
16-lead QSOP package
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-
GENERAL DESCRIPTION
The ADT75181 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°C.
LDAC
nal
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 ADT7518’s wide supply voltage range, low supply current,
and SPI-/I2C-compatible interface make it ideal for a variety of
applications, including personal computers, office equipment,
and domestic appliances.
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 VDD, with an output voltage settling time of 7 ms
typical.
It is recommended that new designs use the ADT7519 rather
than the ADT7518. The ADT7518’s 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.
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/I2C interface.
It features a standby mode that is controlled through the serial
interface.
1 Protected by the following U.S. Patent Numbers: 6,169,442; 5,867,012;
5,764174. Other patents pending.
Rev. A
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