Datasheet

PGA309
www.ti.com SBOS292C –DECEMBER 2003–REVISED JANUARY 2011
ELECTRICAL CHARACTERISTICS (continued)
Boldface limits apply over the specified temperature range, T
A
= –40°C to +125°C.
At T
A
= +25°C, V
SA
= V
SD
= +5V (V
SA
= V
SUPPLY ANALOG
, V
SD
= V
SUPPLY DIGITAL
; V
SA
must equal V
SD
), GND
D
= GND
A
= 0, and V
REF
= REF
IN
/REF
OUT
= +5V, unless otherwise noted.
PGA309
PARAMETER CONDITIONS MIN TYP MAX UNIT
Fault Monitor Circuit
INP_HI, INN_HI Comparator Threshold See
(6)
V
SA
− 1.2 or V
EXC
− 0.1 V
INP_LO, INN_LO Comparator Threshold 40 100 mV
A1SAT_HI, A2SAT_HI Comparator Threshold V
SA
− 0.12 V
A1SAT_LO, A2SAT_LO Comparator Threshold V
SA
− 0.12 V
A3_VCM Comparator Threshold V
SA
− 1.2 V
Comparator Hysteresis 20 mV
Internal Voltage Reference
V
REF1
Register 3, bit D9 = 1 2.46 2.5 2.53 V
V
REF1
Drift vs Temperature +10 ppm/°C
V
REF2
I
PU
Register 3, bit D9 = 0 4.0 4.096 4.14 V
V
REF2
Drift vs Temperature +10 ±7 ppm/°C
Input Current REF
IN
/REF
OUT
Internal V
REF
disabled 100 mA
Output Current REF
IN
/REF
OUT
V
SA
> 2.7V for V
REF
= 2.5V 1 mA
V
SA
> 4.3V for V
REF
= 4.096V 1 mA
Temperature Sense Circuitry (ADC)
Internal Temperature Measurement Register 6, bit D9 = 1
xx Accuracy ±2 °C
xx Resolution 12-Bit + sign, twos complement data format ±0.0625 °C
xx Temperature Measurement Range −55 +150 °C
xx Conversion Rate R
1
, R
0
= ‘11’, 12-bit + sign resolution 24 ms
Temperature ADC
External Temperature Mode Temp PGA + Temp ADC 1 to 8 V/V
xx Gain Range Steps G
PGA
= 1, 2, 4, 8 GND −0.2 V
SA
+0.2 V
xx Analog Input Voltage Range
Temperature ADC Internal REF (2.048V) Register 6, bit D8 = 1
xx Full-Scale Input Voltage (+Input) − (−Input) ±2.048/G
PGA
V
xx Differential Input Impedance 2.8/G
PGA
MΩ
xx Common-Mode Input Impedance G
PGA
= 1 3.5 MΩ
G
PGA
= 2 3.5 MΩ
G
PGA
= 4 1.8 MΩ
G
PGA
= 8 0.9 MΩ
xx Resolution R1, R0 = ‘00’, ADC2X = ‘0’, conversion time = 8ms 11 Bits + Sign
R1, R0 = ‘01’, ADC2X = ‘0’, conversion time = 32ms 13 Bits + Sign
R1, R0 = ‘10’, ADC2X = ‘0’, conversion time = 64ms 14 Bits + Sign
R1, R0 = ‘11’, ADC2X = ‘0’, conversion time = 128ms 15 Bits + Sign
xx Integral Nonlinearity 0.004 %
xx Offset Error G
PGA
= 1 1.2 mV
G
PGA
= 2 0.7 mV
G
PGA
= 4 0.5 mV
G
PGA
= 8 0.4 mV
xx Offset Drift G
PGA
= 1 1.2 mV/°C
G
PGA
= 2 0.6 mV/°C
G
PGA
= 4 0.3 mV/°C
G
PGA
= 8 0.3 mV/°C
(6) When V
EXC
is enabled, a minimum reference selector circuit becomes the reference for the comparator threshold. This minimum
reference selector circuit uses V
EXC
− 100mV and V
SA
− 1.2V and compares the V
INX
pin to the lower of the two references. This
configuration ensures accurate fault monitoring in conditions where V
EXC
might be higher or lower than the input CMR of the PGA input
amplifier relative to V
SA
.
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