7846B Datasheet, PDF (1/11 Pages) Maxwell Technologies – 16-Bit Digital to Analog Converter

7846B
16-Bit Digital to Analog Converter
7846B
V_REF+ 7
R
R
R
V_REF- 8
16
Segment
Switch
Matrix
4
V_CC
21
-+_A2
12-bit DAC
- _A1
12
+
DAC Latch
12
I/O Latch
9
10
3
V_SS
DB15 DB0
Logic Diagram
V_DD
4
R
R
-+_A3
6 R_IN
5 V_OUT
Control
Logic
23 CS
22 R/W
25 LDAC
24 CLR
20
DGND
FEATURES:
• RAD-PAK® technology-hardened against natural
space radiation
• Package:
-28 pin RAD-PAK® Flat Pack
• Microprocessor compatible with readback capability
• 16-Bit monotonicity over temperature
• ±2 LSBs integral linearity error
• Unipolar or bipolar output
• Multiplying capability
• Low power (100 mW typical)
DESCRIPTION:
Maxwell Technologies’ 7846B 16-Bit DAC converter microcir-
cuit features a greater than 100 krad (Si) total dose tolerance,
depending upon space mission. The 7846B has V_REF+ and
V_REF- reference inputs and an on-chip output amplifier which
gives the option of unipolar or bipolar output. The 7846B 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 7846B 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 RAD-PAK® 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, RAD-PAK provides greater than 100
krad (Si) radiation dose tolerance. This product is available
with screening up to Class S.
02.27.08 REV 1
[phone] - Fax: [phone]- www.maxwell.com
All data sheets are subject to change without notice 1
©2008 Maxwell Technologies
All rights reserved.