Datasheet

MSP430FR573x
MSP430FR572x
SLAS639H –JULY 2011–REVISED SEPTEMBER 2013 www.ti.com
REF, External Reference
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)
(1)
PARAMETER TEST CONDITIONS V
CC
MIN TYP MAX UNIT
V
eREF+
Positive external reference voltage input V
eREF+
> V
eREF–
(2)
1.4 AV
CC
V
V
eREF–
Negative external reference voltage input V
eREF+
> V
eREF–
(3)
0 1.2 V
(V
eREF+
–
Differential external reference voltage input V
eREF+
> V
eREF–
(4)
1.4 AV
CC
V
V
REF–
/V
eREF–
)
1.4 V ≤ V
eREF+
≤ V
AVCC
,
V
eREF–
= 0 V,
f
ADC10CLK
= 5 MHz, 2.2 V, 3 V -6 6 µA
ADC10SHTx = 1h,
Conversion rate 200 ksps
I
VeREF+
,
Static input current
I
VeREF–
1.4 V ≤ V
eREF+
≤ V
AVCC
,
V
eREF–
= 0 V,
f
ADC10CLK
= 5 MHz, 2.2 V, 3 V -1 1 µA
ADC10SHTx = 8h,
Conversion rate 20 ksps
C
VREF+
,
Capacitance at VREF+ or VREF- terminal
(5)
10 µF
C
VREF-
(1) The external reference is used during ADC conversion to charge and discharge the capacitance array. The input capacitance, C
i
, 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 10-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 V
CC
MIN TYP MAX UNIT
REFVSEL = {2} for 2.5 V, REFON = 1 3 V 2.4 2.5 2.6
Positive built-in reference
V
REF+
REFVSEL = {1} for 2 V, REFON = 1 3 V 1.92 2.0 2.08 V
voltage output
REFVSEL = {0} for 1.5 V, REFON = 1 3 V 1.44 1.5 1.56
REFVSEL = {0} for 1.5 V 2.0
AVCC minimum voltage,
AV
CC(min)
Positive built-in reference REFVSEL = {1} for 2 V 2.2 V
active
REFVSEL = {2} for 2.5 V 2.7
Operating supply current into f
ADC10CLK
= 5 MHz,
I
REF+
3 V 33 45 µA
AVCC terminal
(1)
REFON = 1, REFBURST = 0
Temperature coefficient of ppm/
T
REF+
REFVSEL = (0, 1, 2}, REFON = 1 ±35
built-in reference °C
AV
CC
= AV
CC (min)
- AV
CC(max)
,
T
A
= 25°C, REFON = 1, 1600
REFVSEL = (0} for 1.5 V
AV
CC
= AV
CC (min)
- AV
CC(max)
,
Power supply rejection ratio
PSRR_DC T
A
= 25°C, REFON = 1, 1900 µV/V
(DC)
REFVSEL = (1} for 2 V
AV
CC
= AV
CC (min)
- AV
CC(max)
,
T
A
= 25°C, REFON = 1, 3600
REFVSEL = (2} for 2.5 V
Settling time of reference AV
CC
= AV
CC (min)
- AV
CC(max)
,
t
SETTLE
30 µs
voltage
(2)
REFVSEL = (0, 1, 2}, REFON = 0 → 1
(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 t
REFON
is less than ± 0.5 LSB.
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