Datasheet

MSP430BT5190
www.ti.com SLAS703A –APRIL 2010–REVISED AUGUST 2013
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
REF–
/V
eREF–
(2)
1.4 AV
CC
V
V
REF–
/V
eREF–
Negative external reference voltage input V
eREF+
> V
REF–
/V
eREF–
(3)
0 1.2 V
(V
eREF+
– Differential external reference voltage
V
eREF+
> V
REF–
/V
eREF–
(4)
1.4 AV
CC
V
V
REF–
/V
eREF–
) input
1.4 V ≤ V
eREF+
≤ V
AVCC
,
V
eREF–
= 0 V
f
ADC12CLK
= 5 2.2 V, 3 V ±8.5 ±26 µA
MHz,ADC12SHTx = 1h,
Conversion rate 200 ksps
I
VeREF+,
Static input current
I
VREF–/VeREF–
1.4 V ≤ V
eREF+
≤ V
AVCC
,
V
eREF–
= 0 V
f
ADC12CLK
= 5 2.2 V, 3 V ±1 µA
MHz,ADC12SHTx = 8h,
Conversion rate 20 ksps
C
VREF+/-
Capacitance at VREF+ or VREF- terminal See
(5)
10 µF
(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 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 ADC12_A. See also the MSP430x5xx and MSP430x6xx Family User's Guide (SLAU208).
REF, Built-In 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
REFVSEL = {2} for 2.5 V,
3 V 2.50 ±1.5%
REFON = REFOUT = 1, I
VREF+
= 0 A
Positive built-in reference REFVSEL = {1} for 2.0 V,
V
REF+
3 V 1.98 ±1.5% V
voltage output REFON = REFOUT = 1, I
VREF+
= 0 A
REFVSEL = {0} for 1.5 V, 2.2 V, 3
1.49 ±1.5%
REFON = REFOUT = 1, I
VREF+
= 0 A V
REFVSEL = {0} for 1.5 V, reduced
1.8
performance
AVCC minimum voltage,
REFVSEL = {0} for 1.5 V 2.2
AV
CC(min)
Positive built-in reference V
active
REFVSEL = {1} for 2.0 V 2.3
REFVSEL = {2} for 2.5 V 2.8
REFON = 1, REFOUT = 0, REFBURST = 0 3 V 100 140 µA
Operating supply current into
I
REF+
AVCC terminal
(2) (3)
REFON = 1, REFOUT = 1, REFBURST = 0 3 V 0.9 1.5 mA
REFVSEL = {0, 1, 2},
Load-current regulation, I
VREF+
= +10 µA/–1000 µA,
I
L(VREF+)
2500 µV/mA
VREF+ terminal
(4)
AV
CC
= AV
CC (min)
for each reference level,
REFVSEL = (0, 1, 2}, REFON = REFOUT = 1
(1) The reference is supplied to the ADC by the REF module and is buffered locally inside the ADC. The ADC uses two internal buffers, one
smaller and one larger for driving the VREF+ terminal. When REFOUT = 1, the reference is available at the VREF+ terminal, as well as,
used as the reference for the conversion and utilizes the larger buffer. When REFOUT = 0, the reference is only used as the reference
for the conversion and utilizes the smaller buffer.
(2) The internal reference current is supplied via terminal AVCC. Consumption is independent of the ADC12ON control bit, unless a
conversion is active. REFOUT = 0 represents the current contribution of the smaller buffer. REFOUT = 1 represents the current
contribution of the larger buffer without external load.
(3) The temperature sensor is provided by the REF module. Its current is supplied via terminal AVCC and is equivalent to I
REF+
with
REFON =1 and REFOUT = 0.
(4) Contribution only due to the reference and buffer including package. This does not include resistance due to PCB trace, etc.
Copyright © 2010–2013, Texas Instruments Incorporated Submit Documentation Feedback 65
Product Folder Links: MSP430BT5190