adc12d800rfrb National Semiconductor Corporation, adc12d800rfrb Datasheet - Page 51

• Manufacturer Part Number: adc12d800rfrb
• Description: 12-bit, 1.6/1.0 Gsps Rf Sampling Adc
• Manufacturer: National Semiconductor Corporation

17.7 RECOMMENDED SYSTEM CHIPS
National recommends these other chips including tempera-
ture sensors, clocking devices, and amplifiers in order to
support the ADC12D800/500RF in a system design.
17.7.1 Temperature Sensor
The ADC12D800/500RF has an on-die temperature diode
connected to pins Tdiode+/- which may be used to monitor
the die temperature. National also provides a family of tem-
17.7.2 Clocking Device
The clock source can be a PLL/VCO device such as the
LMX2531LQxxxx family of products. The specific device
should be selected according to the desired ADC sampling
clock
LMX2531LQ1570E, with the ADC clock source provided by
frequency.
FIGURE 25. Supply and DCLK Ramping
The
ADC12D800RFRB
FIGURE 26. Typical Temperature Sensor Application
uses
30128690
the
51
perature sensors for this application which monitor different
numbers of external devices, see
The temperature sensor (LM95235/13/14) is an 11-bit digital
temperature sensor with a 2-wire System Management Bus
(SMBus) interface that can monitor the temperature of one,
two, or four remote diodes as well as its own temperature. It
can be used to accurately monitor the temperature of up to
one,
ADC12D800/500RF, a FPGA, other system components, and
the ambient temperature.
The temperature sensor reports temperature in two different
formats for +127.875°C/-128°C range and 0°/255°C range. It
has a Sigma-Delta ADC core which provides the first level of
noise immunity. For improved performance in a noisy envi-
ronment, the temperature sensor includes programmable dig-
ital filters for Remote Diode temperature readings. When the
digital filters are invoked, the resolution for the Remote Diode
readings increases to 0.03125°C. For maximum flexibility and
best accuracy, the temperature sensor includes offset regis-
ters that allow calibration for other types of diodes.
Diode fault detection circuitry in the temperature sensor can
detect the absence or fault state of a remote diode: whether
D+ is shorted to the power supply, D- or ground, or floating.
In the following typical application, the LM95213 is used to
monitor the temperature of an ADC12D800/500RF as well as
an FPGA, see
+/- pins may be left floating.
the Aux PLL output. Other devices which may be considered
based on clock source, jitter cleaning, and distribution pur-
poses are the LMK01XXX, LMK02XXX, LMK03XXX and
LMK04XXX product families.
TABLE 27. Temperature Sensor Recommendation
Number of External
Devices Monitored
two,
1
2
4
or
Figure
four
26. If this feature is unused, the Tdiode
30128697
external
Recommended Temperature
Table
devices
LM95235
LM95213
LM95214
Sensor
27.
such
www.national.com
as
the