7846A
16-Bit Digital to Analog Converter
V
CC
21
V
REF+
7
R
V
DD
4
R
-
A2
+
R
-
A3
+
6
R
IN
R
16
Segment
Switch
Matrix
-
A1
+
4
5
V
OUT
12-bit DAC
12
23
CS
R/W
R
7846A
V
REF-
8
DAC Latch
12
Control
Logic
22
25 LDAC
24
CLR
I/O Latch
9
V
SS
10
DB15
3
DB0
20
DGND
Memory
Logic Diagram
F
EATURES
:
鈥?R
AD
-P
AK
庐 technology-hardened against natural
space radiation
鈥?Total dose hardness:
- > 100 krad (Si), depending upon space mission
鈥?Excellent Single Event Effects
- SEL
TH
> 114 MeV/mg/cm
2
- SEU < 8 MeV/mg/cm
2
鈥?Package:
-28 pin R
AD
-P
AK
庐 Flat Pack
鈥?Microprocessor compatible with readback capability
鈥?16-Bit monotonicity over temperature
鈥?卤2 LSBs integral linearity error
鈥?Unipolar or bipolar output
鈥?Multiplying capability
鈥?Low power (100 mW typical)
D
ESCRIPTION
:
Maxwell Technologies鈥?7846A 16-Bit DAC converter microcir-
cuit features a greater than 100 krad (Si) total dose tolerance,
depending upon space mission. The 7846A has V
REF+
and
V
REF-
reference inputs and an on-chip output amplifier which
gives the option of unipolar or bipolar output. The 7846A uses
a segmented architecture. The 4 MSBs in the DAC latch
select one of the segments in a 16-resistor string. Both taps of
the segment are buffered by amplifiers and fed to a 12-bit
DAC, which provides a further 12 bits of resolution. This archi-
tecture ensures 16-bit monotonicity. Excellent integral linearity
results from tight matching between the input offset voltages
of the two buffer amplifiers. In addition to the excellent accu-
racy specifications, the 7846A also offers a comprehensive
microprocessor interface. There are 16 data I/O pins, plus
control lines (CS, R/W, LDAC and CLR). R/W and CS have
readback function which allows writing to and reading from the
I/O latch.
Maxwell Technologies' patented R
AD
-P
AK
庐 packaging technol-
ogy incorporates radiation shielding in the microcircuit pack-
age. It eliminates the need for box shielding while providing
the required radiation shielding for a lifetime in orbit or space
mission. In a GEO orbit, R
AD
-P
AK
provides greater than 100
krad (Si) radiation dose tolerance. This product is available
with screening up to Class S.
05.29.03 REV 5
All data sheets are subject to change without notice
1
(619) 503-3300 - Fax: (619) 503-3301- www.maxwell.com
漏2003 Maxwell Technologies
All rights reserved.
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