AD9148 Analog Devices, AD9148 Datasheet - Page 65

• Manufacturer Part Number: AD9148
• Manufacturer: Analog Devices

Specifications of AD9148

• Resolution (bits): 16bit
• Dac Update Rate: 1GSPS
• Dac Settling Time: n/a
• Max Pos Supply (v): +3.47V
• Single-supply: No
• Dac Type: Current Out
• Dac Input Format: LVDS,Par

Data Sheet
TEMPERATURE SENSOR
The
the temperature of the die. The temperature reading is accessed
by Register 0x5E and Register 0x5F. The temperature of the die
can be calculated as
where T
temperature accuracy is ±5°C typical over the +85°C to
−35°C range. A typical plot of the
vs. die temperature code readback is shown in Figure 90.
AD9148
T
27,500
25,000
22,500
20,000
17,500
15,000
12,500
10,000
Figure 90. Die Temperature vs. Die Temperature Code Readback
7,500
DIE
DIE
–40 –30 –20 –10
=
is the die temperature in degrees Celsius. The
(
DieTemp
has a diode-based temperature sensor for measuring
MEASURED DIE TEMPERATURE
CALCULATED DIE TEMPERATURE
+5°C
–5°C
[
15
130
0
:
] 0
10 20 30 40 50 60 70 80 90 100
TEMPERATURE (°C)
−
13
,
700
AD9148
)
die temperature
Rev. B | Page 65 of 72
Estimates of the ambient temperature can be made if the power
dissipation of the device is known. For example, if the device power
dissipation is 800 mW and the measured die temperature is 50°C,
then the ambient temperature can be calculated as
where:
T
T
AD9148
To use the temperature sensor, it must be enabled by setting
Bit 0, Register 0x5C to 0. Before the temperature sensor data
can be read back, it must be latched by toggling Bit 1, Register 0x5C
from 0 to 1. In addition, to get accurate readings, the die temperature
control register (Register 0x5D) should be set to 0x0A.
A
JA
is the ambient temperature in degrees Celsius.
is the thermal resistance from junction to ambient of the
T
A
= T
as shown in Table 7.
DIE
– P
D
× T
JA
= 50 – 0.8 × 18 = 35.6°C
AD9148