X96011 Datasheet, PDF (16/23 Pages) Intersil Corporation – Temperature Sensor with Look Up Table Memory and DAC

X96011
Figure 8. D/A Converter Power-on Reset Response
Voltage
Vcc
V_ADCOK
0V
Current
ADC TIME
I_x x 10%
The options are summarized in the following tables:
D/A Converter Access Summary
LDAS DDAS
Control Source
0
0
A/D converter through LUT
(Default)
1
0
Bits LDA5 - LDA0 through LUT
X
1
Bits DDA7 - DDA0
“X” = Don’t Care Condition (May be either “1” or “0”)
Bit DDAS is used to bypass the A/D converter and
look-up table, allowing direct access to the input of the
D/A converter with the byte in control register 3. See
Figure 6, and the descriptions of the control bits.
Bit IDS in Control Register 0 select the direction of the
current through pin Iout. See Figure 5, and the
descriptions of the control bits.
Time
I_x
Time
POWER-ON RESET
When power is applied to the Vcc pin of the X96011, the
device undergoes a strict sequence of events before the
current outputs of the D/A converters are enabled.
When the voltage at Vcc becomes larger than the
power-on reset threshold voltage (V_POR), the device
recalls all control bits from non-volatile memory into
volatile registers. Next, the analog circuits are pow-
ered up. When the voltage at Vcc becomes larger than
a second voltage threshold (V_ADCOK), the ADC is
enabled. In the default case, after the ADC performs
four consecutive conversions with the same exact
result, the ADC output is used to select a byte from the
look-up table. The byte becomes the input of the DAC.
During all the previous sequence the input of the DAC
is 00h. If bit ADCfiltOff is “1”, only one ADC conversion
is necessary. Bit DDAS and LDAS, also modify the
way the DAC is accessed the first time after power-up,
as described in “Control Register 5” on page 12.
The X96011 is a hot pluggable device. Voltage dis-
trubances on the Vcc pin are handled by the power-on
reset circuit, allowing proper operation during hot plug-
in applications.
16
FN8215.1
October 25, 2005