ISL21400 Datasheet, PDF (1/17 Pages) Intersil Corporation – Programmable Temperature Slope Voltage Reference

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Data Sheet
December 14, 2006
ISL21400
FN8091.0
Programmable Temperature Slope
Voltage Reference
The ISL21400 features a precision voltage reference
combined with a temperature sensor whose output voltage
varies linearly with temperature. The precision 1.20V
reference has a very low temperature coefficient (tempco),
and its output voltage is scaled by an internal DAC (V_REF) to
produce a temperature stable output voltage that is
programmable from 0V to 1.20V. The output voltage from the
temperature sensor (V_TS) is summed with V_REF to produce
a temperature dependent output voltage.
The slope of the V_TS portion of the output voltage can be
programmed to be positive or negative in the range
-2.1mV/°C to +2.1mV/°C. A programmable gain amplifier
(PGA) sums the V_TS and the V_REF voltages and provides
gains of 1x, 2x, and 4x to scale the output up to 4.8V and the
slope to ±8.4mV/°C.
The V_REF and V_TS terms are programmable with 8 bits of
resolution via an I²C bus and the values are stored in non-
volatile registers. The PGA gain is also set via the I²C bus
and the value is stored in a non-volatile register. Non-volatile
memory storage assures the programmed settings are
retained on power-down, eliminating the need for software
initialization at device power-up.
Temperature Characteristics Curve
3.0
A_V = 2
2.5
2.0
TS = 0
1.5
1.0
TS = 0
0.5
TS = 127
A_V = 1
TS = 255
TS = 255 _{TS = 127}
0.0
-40
-15
10
35
60
85
TEMPERATURE (°C)
Features
• Programmable reference voltage
• Programmable temperature slope
• Programmable Gain Amplifier
• Non-volatile storage of programming registers
• I²C serial interface
• 2% total accuracy over temperature and V_CC range
• 200µA typical active supply current
• Operating temperature range = -40°C to +85°C
• 8 Ld MSOP package
Applications
• RF power amplifier bias compensation
• LCD bias compensation
• Laser diode bias compensation
• Sensor bias and linearization
• Data acquisition systems
• Variable DAC reference
• Amplifier biasing
Pinout
ISL21400
(8 LD MSOP)
TOP VIEW
A2
1
A1
2
A0 3
V_SS
4
8
V_CC
7
V_OUT
6
SDA
5
SCL
Ordering Information
PART NUMBER (Note)
PART MARKING
V_DD RANGE
(V)
TEMP RANGE
(°C)
PACKAGE
PKG. DWG. #
ISL21400IU8Z
DEW
2.7 to 5.5
-40 to +85
8 Ld MSOP (Pb-free)
M8.118
ISL21400IU8Z-TK
DEW
2.7 to 5.5
-40 to +85
8 Ld MSOP (Pb-free)
M8.118
NOTE: Intersil Pb-free products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination
finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at
Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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