Datasheet

Positive
Negative
V
R+
Gain Error
Offset Error
DAC Code
DAC V
OUT
Ideal transfer
function
R
Load
=
AV
CC
C
Load
= 100pF
2
DAC Output
MSP430F261x
MSP430F241x
www.ti.com SLAS541K –JUNE 2007–REVISED NOVEMBER 2012
12-Bit DAC Linearity Specifications
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)
PARAMETER TEST CONDITIONS V
CC
MIN TYP MAX UNIT
Resolution 12-bit monotonic 12 bits
V
REF
= 1.5 V,
2.2 V ±2.0 ±8.0
DAC12AMPx = 7, DAC12IR = 1
INL Integral nonlinearity
(1)
LSB
V
REF
= 2.5 V,
3 V
DAC12AMPx = 7, DAC12IR = 1
V
REF
= 1.5 V,
2.2 V ±0.4 ±1.0
DAC12AMPx = 7, DAC12IR = 1
DNL Differential nonlinearity
(1)
LSB
V
REF
= 2.5 V,
3 V
DAC12AMPx = 7, DAC12IR = 1
V
REF
= 1.5 V,
2.2 V ±21
DAC12AMPx = 7, DAC12IR = 1
Offset voltage without
calibration
(1)(2)
V
REF
= 2.5 V,
3 V
DAC12AMPx = 7, DAC12IR = 1
E
O
mV
V
REF
= 1.5 V,
2.2 V ±2.5
DAC12AMPx = 7, DAC12IR = 1
Offset voltage with
calibration
(1)(2)
V
REF
= 2.5 V,
3 V
DAC12AMPx = 7, DAC12IR = 1
Offset error temperature
d
E(O)
/d
T
2.2 V, 3 V 30 µV/C
coefficient
(3)
V
REF
= 1.5 V 2.2 V ±3.50
E
G
Gain error
(3)
% FSR
V
REF
= 2.5 V 3 V
10 ppm of
d
E(G)
/d
T
Gain temperature coefficient
(3)
2.2 V, 3 V
FSR/°C
DAC12AMPx = 2 100
t
Offset_Cal
Time for offset calibration
(4)
DAC12AMPx = 3, 5 2.2 V, 3 V 32 ms
DAC12AMPx = 4, 6, 7 6
(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. VDAC12_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) 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. VDAC12_xOUT = E
O
+ (1 + E
G
) × (V
eREF+
/4095) × DAC12_xDAT, DAC12IR = 1.
(4) 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}. The DAC12 module should be configured prior to initiating calibration. Port activity during calibration may affect accuracy and is
not recommended.
Figure 41. Linearity Test Load Conditions and Gain/Offset Definition
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