X96011_08 Datasheet, PDF (7/18 Pages) Intersil Corporation – Temperature Sensor with Look-Up Table Memory and DAC

X96011
Device Description
The combination of the X96011 functionality and Intersil’s
QFN package lowers system cost, increases reliability, and
reduces board space requirements.
The on-chip Programmable Current Generator may be
independently programmed to either sink or source current.
The maximum current generated is determined by using an
externally connected programming resistor, or by selecting
one of three predefined values. Both current generators
have a maximum output of ±1.6 mA, and may be controlled
to an absolute resolution of 0.39% (256 steps/8 bit).
The current generator is driven using either an on-board
temperature sensor or control registers. The internal
temperature sensor operates over a very broad temperature
range (-40°C to +100°C). The sensor output drives an 8-bit
A/D converter. The six MSBs of the ADC output selects one
of 64 bytes from the nonvolatile look-up table (LUT).
The contents of the selected LUT row (8-bit wide) drives the
input of an 8-bit D/A converter, which generates the output
current. All control and setup parameters of the X96011,
including the look-up table, are programmable via the 2-wire
serial port.
Principles of Operation
Control and Status Registers
The Control and Status Registers provide the user with a
mechanism for changing and reading the value of various
parameters of the X96011. The X96011 contains five
Controls, one Status, and several Reserved registers, each
being one Byte wide (See Figure 4). The Control registers 0
through 6 are located at memory addresses 80h through 86h
respectively. The Status register is at memory address 87h,
and the Reserved registers at memory address 82h, 84h,
and 88h through 8Fh.
All bits in Control register 6 always power-up to the logic state
“0”. All bits in Control registers 0 through 5 power-up to the
logic state value kept in their corresponding nonvolatile
memory cells. The nonvolatile bits of a register retain their
stored values even when the X96011 is powered down, then
powered back up. The nonvolatile bits in Control 0 through
Control 5 registers are all preprogrammed to the logic state “0”
at the factory, except the cases that indicate “1” in Figure 1.
Bits indicated as “Reserved” are ignored when read, and
must be written as “0”, if any Write operation is performed to
their registers.
A detailed description of the function of each of the Control
and Status register bits follows.
Control Register 0
This register is accessed by performing a Read or Write
operation to address 80h of memory.
ADCFILTOFF: ADC FILTERING CONTROL
(NON-VOLATILE)
When this bit is “1”, the status register at 87h is updated after
every conversion of the ADC. When this bit is “0” (default),
the status register is updated after four consecutive
conversions with the same result, on the 6 MSBs.
NV13: CONTROL REGISTERS 1 AND 3 VOLATILITY
MODE SELECTION BIT (NON-VOLATILE)
When the NV13 bit is set to “0” (default), bytes written to
Control registers 1 and 3 are stored in volatile cells, and their
content is lost when the X96011 is powered down. When the
NV13 bit is set to “1”, bytes written to Control registers 1 and
3 are stored in both volatile and nonvolatile cells, and their
value doesn’t change when the X96011 is powered down
and powered back up. See “Writing to Control Registers” on
page 16.
IDS: CURRENT GENERATOR DIRECTION SELECT BIT
(NON-VOLATILE)
The IDS bit sets the polarity of the Current Generator. When
this bit is set to “0” (default), the Current Generator of the
X96011 is configured as a Current Source. The Current
Generator is configured as a Current Sink when the IDS bit
is set to “1”. See Figure 5.
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FN8215.2
February 25, 2008