Texas Instruments MSP430CG4616IPZ, Manual

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MSP430xG461x
MIXED SIGNAL MICROCONTROLLER
SLAS508I − APRIL 2006 − REVISED MARCH 2011
54
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature (unless otherwise
noted) (continued)
12-bit DAC, linearity specifications (see Figure 26)
PARAMETER TEST CONDITIONS V
CC
MIN TYP MAX UNIT
Resolution (12-bit Monotonic) 12 bits
INL
Integral nonlinearity
V
ref
= 1.5 V,
DAC12AMPx = 7, DAC12IR = 1
2.2 V
±
2 0
±
8 0 LSB INL
Integral nonlinearity
(see Note 1)
V
ref
= 2.5 V,
DAC12AMPx = 7, DAC12IR = 1
3 V
±
2.0
±
8.0 LSB
DNL
Differential nonlinearity
V
ref
= 1.5 V,
DAC12AMPx = 7, DAC12IR = 1
2.2 V
±
0 4
±
1 0 LSB DNL
Differential nonlinearity
(see Note 1)
V
ref
= 2.5 V,
DAC12AMPx = 7, DAC12IR = 1
3 V
±
0.4
±
1.0 LSB
Offset voltage without
calibration
V
ref
= 1.5 V,
DAC12AMPx = 7, DAC12IR = 1
2.2 V
±
21
E
O
calibration
(see Notes 1, 2)
V
ref
= 2.5 V,
DAC12AMPx = 7, DAC12IR = 1
3 V
±
21
mV
Offset voltage with
calibration
V
ref
= 1.5 V,
DAC12AMPx = 7, DAC12IR = 1
2.2 V
±
2 5
mV
calibration
(see Notes 1, 2)
V
ref
= 2.5 V,
DAC12AMPx = 7, DAC12IR = 1
3 V
±
2.5
d
E(O)
/d
T
Offset error
temperature coefficient
(see Note 1)
2.2 V/3 V
±
30
μ
V/
°
C
E Gain error (see Note 1)
V
REF
= 1.5 V 2.2 V
±
3 50 % FSR E
G
Gain error (see Note 1)
V
REF
= 2.5 V 3 V
±
3.50 % FSR
d
E(G)
/d
T
Gain temperature
coefficient (see Note 1)
2.2 V/3 V 10
ppm of
FSR/
°
C
Time for offset calibration
DAC12AMPx = 2 100
t
Offset_Cal
Time for offset calibration
(see Note 3)
DAC12AMPx = 3,5
2.2 V/3 V
32
ms t
Offset_Cal
(see Note 3)
DAC12AMPx = 4,6,7
2.2 V/3 V
6
ms
NOTES: 1. Parameters calculated from the best-fit curve from 0x0A to 0xFFF. The best-fit curve method is used to deliver coefficients “a” and
“b” of the first order equation: y = a + b*x. V
DAC12_xOUT
= E
O
+ (1 + E
G
) * (V
eREF+
/4095) * DAC12_xDAT, DAC12IR = 1.
2. The offset calibration works on the output operational amplifier. Offset Calibration is triggered setting bit DAC12CALON
3. The offset calibration can be done if DAC12AMPx = {2, 3, 4, 5, 6, 7}. The output operational amplifier is switched off with
DAC12AMPx = {0, 1}. It is recommended that the DAC12 module be configured prior to initiating calibration. Port activity during
calibration may effect accuracy and is not recommended.
Positive
Negative
VR+
Gain Error
Offset Error
DAC Code
DAC VOUT
Ideal transfer
function
RLoad =
AVCC
CLoad = 100pF
2
DAC Output
Figure 26. Linearity Test Load Conditions and Gain/Offset Definition