Datasheet

XTR108
4
SBOS187C
www.ti.com
XTR108EA
PARAMETER CONDITIONS MIN TYP MAX UNITS
ELECTRICAL CHARACTERISTICS (Cont.)
Boldface limits apply over the specified temperature range, T
A
= –40°C to +85°C.
At T
A
= +25°C, V
PS
= 24V, and Supertex DN2540 external depletion-mode FET transistor, unless otherwise noted, all voltages measured with respect to I
RET
pin.
NOTES: (1) Over-scale and under-scale complies with NAMUR NE43 recommendation. (2) Span adjustment is determined by PGA gain and sensor
excitation. (3) Span can be digitally adjusted in three ways: PGA gain, current reference Coarse, and current reference Fine. (4) RTI = Referred to Input.
(5) Current source output voltage measured with respect to I
RET
. (6) RTO = Referred to Output. (7) Excitation DAC range sufficient to adjust span fully
between PGA gain steps. (8) Output current into external circuitry is limited by an external MOS power FET. (9) Measured with over- and under-scale limits
disabled.
OVER- AND UNDER-SCALE LIMITING
Over-Scale DAC: 16 Steps 4 Bits
Adjustment Range
RTO
(6)
of Current Amplifier R
VI
= 6.34kΩ 20.7 to 28.1 mA
RTO
(6)
of PGA 2.625 to 3.563 V
Step Size
RTO
(6)
of Current Amplifier 0.49 mA
RTO
(6)
of PGA 62.5 mV
Accuracy ±10 %
Under-Scale DAC: 8 Steps 3 Bits
Adjustment Range
RTO
(6)
of Current Amplifier R
VI
= 6.34kΩ 2.17 to 3.55 mA
RTO
(6)
of PGA 275 to 450 mV
Step Size
RTO
(6)
of Current Amplifier 0.195 mA
RTO
(6)
of PGA 25 mV
Accuracy ±5%
VOLTAGE REFERENCE, V
REF
Internal Bandgap 1.193 V
vs Temperature ±5 ±50 ppm/°C
UNCOMMITTED OP AMP
Input
Offset Voltage V
CM
= 2V ±2mV
vs Temperature ±3 µV/°C
vs Common-Mode Voltage 90 dB
Open-Loop Gain 110 dB
Common-Mode Input Range 0 to 3.5 V
Output Voltage Range R
L
= 10kΩ to V
S
/2 0.2 V
S
– 0.2 V
DIGITAL INPUT/OUTPUT
Logic Family CMOS
Logic Levels
V
IL
0 0.8 V
V
IH
3.5 V
S
V
V
OL
I
OL
= 300µA 0.4 V
V
OH
I
OH
= –300µAV
S
– 1V
Input Current
I
IH
(CS1) 3.5 < V
IN
< V
S
–200 –120 10 µA
I
IL
(CS1) 0 < V
IN
< 0.8 –20 –610 µA
I
IH
, I
IL
(SCLK, DIO) 0 < V
IN
< V
S
–20 –610 µA
INTERNAL OSCILLATOR
Frequency, f
OSC
210 kHz
TEMPERATURE RANGE
Specification –40 +85 °C
Operating –55 +125 °C
θ
JA
, Junction to Ambient 100 °C/W
LOOP SUPPLY
Voltage Range with Supertex DN2540 7.5 V
Quiescent Current R
SET
Open, L
IN
Reg = 0, No Sensor Current
(8)(9)
0.5 mA