Datasheet

®
6
DAC813
20
10
0
–10
–20
–40
Around +10V (mV)
–2
Time (µs)
SETTLING TIME, –10V TO +10V
+5
0
∆
WR (V)
02468101214
V
OUT
WR
V
OUT
1LSB = 4.88mV
20
10
0
–10
–20
Around –10V (mV)
–2
Time (µs)
SETTLING TIME, +10V TO –10V
+5
0
0 2 4 6 8 10 12
WR (V)
∆
1LSB = 4.88mV
V
OUT
WR
TYPICAL PERFORMANCE CURVES (CONT)
At T
A
= +25°C, V
CC
= ±15V, unless otherwise noted.
DISCUSSION OF
SPECIFICATIONS
INPUT CODES
The DAC813 accepts positive-true binary input codes.
DAC813 may be connected by the user for any one of the
following codes: USB (Unipolar Straight Binary), BOB
(Bipolar Offset Binary) or, using an external inverter on the
MSB line, BTC (Binary Two’s Complement). See Table I.
MONOTONICITY
A D/A converter is monotonic if the output either increases
or remains the same for increasing digital inputs. All grades
of DAC813 are monotonic over their specification tempera-
ture range.
DRIFT
Gain Drift is a measure of the change in the Full Scale Range
(FSR) output over the specification temperature range. Gain
Drift is expressed in parts per million per degree Celsius
(ppm/°C).
Unipolar Offset Drift is measured with a data input of
000
HEX
. The D/A is configured for unipolar output. Unipolar
Offset Drift is expressed in parts per million of Full Scale
Range per degree Celsius (ppm of FSR/°C).
Bipolar Zero Drift is measured with a data input of 800
HEX
.
The D/A is configured for bipolar output. Bipolar Zero Drift
is expressed in parts per million of Full Scale Range per
degree Celsius (ppm of FSR/°C).
SETTLING TIME
Settling Time is the total time (including slew time) for the
output to settle within an error band around its final value
after a change in input. Three settling times are specified to
±0.012% of Full Scale Range (FSR): two for maximum full
scale range changes of 20V and 10V, and one for a 1LSB
change. The 1LSB change is measured at the major carry
(7FF
HEX
to 800
HEX
and 800
HEX
to 7FF
HEX
), the input tran-
sition at which worst-case settling time occurs.
REFERENCE SUPPLY
DAC813 contains an on-chip +10V reference. This voltage
(pin 6) has a tolerance of ±50mV. V
REF OUT
must be con-
nected to V
REF IN
through a gain adjust resistor with a
nominal value of 500Ω. The connection can be made through
an optional 1kΩ trim resistor to provide adjustment to zero
DIGITAL ANALOG OUTPUT
INPUT
USB BOB BTC*
Unipolar Bipolar Binary
Straight Offset Two’s
MSB to LSB Binary Binary Complement
FFF
HEX
+ Full Scale + Full Scale Zero – 1LSB
800
HEX
+ 1/2 Full Scale Zero – Full Scale
7FF
HEX
+ 1/2 Full Scale – 1LSB Zero – 1LSB + Full Scale
000
HEX
Zero – Full Scale Zero
* Invert MSB of BOB code with external inverter to obtain BTC code.
TABLE I. Digital Input Codes.
LINEARITY ERROR
Linearity error as used in D/A converter specifications by
Burr-Brown is the deviation of the analog output from a
straight line drawn between the end points (inputs all “1s”
and all “0s”). The DAC813 linearity error is specified at
±1/4LSB (max) at +25°C K grades, and ±1/2LSB (max) for
J grades.
DIFFERENTIAL LINEARITY ERROR
Differential linearity error (DLE) is the deviation from a
1LSB output change from one adjacent state to the next. A
DLE specification of 1/2LSB means that the output step size
can range from 1/2LSB to 3/2LSB when the input changes
from one state to the next. Monotonicity requires that DLE
be less than 1LSB over the temperature range of interest.