MSP430FR573x
MSP430FR572x
www.ti.com
SLAS639D –JULY 2011–REVISED AUGUST 2012
REF, External Reference
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)
(1)
PARAMETER
TEST CONDITIONS
VCC
MIN
1.4
0
TYP
MAX UNIT
(2)
VeREF+
VeREF–
(VeREF+
Positive external reference voltage input
VeREF+ > VeREF–
AVCC
1.2
V
V
(3)
(4)
Negative external reference voltage input VeREF+ > VeREF–
–
Differential external reference voltage
VeREF+ > VeREF–
1.4
AVCC
V
VREF–/VeREF–
)
input
1.4 V ≤ VeREF+ ≤ VAVCC
VeREF– = 0 V,
,
fADC10CLK = 5 MHz,
ADC10SHTx = 1h,
Conversion rate 200 ksps
2.2 V, 3 V
2.2 V, 3 V
-6
6
µA
IVeREF+
IVeREF–
,
Static input current
1.4 V ≤ VeREF+ ≤ VAVCC
VeREF– = 0 V,
fADC10CLK = 5 MHz,
ADC10SHTx = 8h,
,
-1
1
µA
µF
Conversion rate 20 ksps
Capacitance at VREF+ or VREF- terminal
CVREF+, CVREF-
10
(5)
(1) The external reference is used during ADC conversion to charge and discharge the capacitance array. The input capacitance, Ci, is also
the dynamic load for an external reference during conversion. The dynamic impedance of the reference supply should follow the
recommendations on analog-source impedance to allow the charge to settle for 12-bit accuracy.
(2) The accuracy limits the minimum positive external reference voltage. Lower reference voltage levels may be applied with reduced
accuracy requirements.
(3) The accuracy limits the maximum negative external reference voltage. Higher reference voltage levels may be applied with reduced
accuracy requirements.
(4) The accuracy limits minimum external differential reference voltage. Lower differential reference voltage levels may be applied with
reduced accuracy requirements.
(5) Two decoupling capacitors, 10 µF and 100 nF, should be connected to VREF to decouple the dynamic current required for an external
reference source if it is used for the ADC10_B. Also see the MSP430FR57xx Family User's Guide (SLAU272).
REF, Built-In Reference
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)
PARAMETER
TEST CONDITIONS
REFVSEL = {2} for 2.5 V, REFON = 1
REFVSEL = {1} for 2 V, REFON = 1
REFVSEL = {0} for 1.5 V, REFON = 1
REFVSEL = {0} for 1.5 V
VCC
3 V
3 V
3 V
MIN
2.4
TYP
2.5
2.0
1.5
MAX UNIT
2.6
Positive built-in reference
voltage output
VREF+
1.92
1.44
2.0
2.08
1.56
V
AVCC minimum voltage,
Positive built-in reference
active
AVCC(min)
REFVSEL = {1} for 2 V
2.2
V
REFVSEL = {2} for 2.5 V
2.7
Operating supply current into fADC10CLK = 5 MHz,
IREF+
3 V
33
45
µA
(1)
AVCC terminal
REFON = 1, REFBURST = 0
Temperature coefficient of
built-in reference
ppm/
°C
TREF+
REFVSEL = (0, 1, 2}, REFON = 1
±35
AVCC = AVCC (min) - AVCC(max)
TA = 25°C, REFON = 1,
REFVSEL = (0} for 1.5 V
,
,
,
,
1600
1900
AVCC = AVCC (min) - AVCC(max)
TA = 25°C, REFON = 1,
REFVSEL = (1} for 2 V
Power supply rejection ratio
(DC)
PSRR_DC
µV/V
AVCC = AVCC (min) - AVCC(max)
TA = 25°C, REFON = 1,
REFVSEL = (2} for 2.5 V
3600
30
Settling time of reference
voltage
AVCC = AVCC (min) - AVCC(max)
REFVSEL = (0, 1, 2}, REFON = 0 → 1
tSETTLE
µs
(2)
(1) The internal reference current is supplied by terminal AVCC. Consumption is independent of the ADC10ON control bit, unless a
conversion is active. The REFON bit enables to settle the built-in reference before starting an A/D conversion.
(2) The condition is that the error in a conversion started after tREFON is less than ±0.5 LSB.
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