Datasheet
REV.–4–
AD7226
PIN CONFIGURATIONS
DIP and SOIC/SSOP
TOP VIEW
(Not to Scale)
20
19
18
17
16
15
14
13
12
11
1
2
3
4
5
6
7
8
9
10
AD7226
V
REF
AGND
DGND
DB7 (MSB)
DB6
A0
A1
WR
DB0(LSB)
DB5
DB4
DB3
DB2
DB1
V
SS
V
OUT
A
V
OUT
BV
OUT
C
V
OUT
D
V
DD
PLCC
3 2 1 20 19
9 10 11 12 13
18
17
16
15
14
4
5
6
7
8
TOP VIEW
(Not to Scale)
V
REF
AGND
DGND
DB7 (MSB)
DB8
AD7226
V
DD
A0
A1
WR
DB0(LSB)
DB5
DB4
DB3
DB2
DB1
V
SS
V
OUT
A
V
OUT
B
V
OUT
C
V
OUT
D
TERMINOLOGY
TOTAL UNADJUSTED ERROR
This is a comprehensive specification that includes full-scale
error, relative accuracy and zero code error. Maximum output
voltage is V
REF
– 1 LSB (ideal), where 1 LSB (ideal) is V
REF
/
256. The LSB size will vary over the V
REF
range. Hence the zero
code error will, relative to the LSB size, increase as V
REF
decreases.
Accordingly, the total unadjusted error, which includes the zero
code error, will also vary in terms of LSB’s over the V
REF
range.
As a result, total unadjusted error is specified for a fixed refer-
ence voltage of 10 V.
RELATIVE ACCURACY
Relative Accuracy or endpoint nonlinearity, is a measure of the
maximum deviation from a straight line passing through the
endpoints of the DAC transfer function. It is measured after
allowing for zero and full-scale error and is normally expressed
in LSB’s or as a percentage of full-scale reading.
DIFFERENTIAL NONLINEARITY
Differential Nonlinearity is the difference between the measured
change and the ideal 1 LSB change between any two adjacent
codes. A specified differential nonlinearity of ± 1 LSB max over
the operating temperature range ensures monotonicity.
DIGITAL CROSSTALK
The glitch impulse transferred to the output of one converter
due to a change in the digital input code to another of the con-
verters. It is specified in nV secs and is measured at V
REF
= 0 V.
FULL SCALE ERROR
Full-Scale Error is defined as:
Measured Value – Zero Code Error – Ideal Value
4
o
f
1
4
D