hs3120b-2-883 Exar Corporation, hs3120b-2-883 Datasheet - Page 5

• Manufacturer Part Number: hs3120b-2-883
• Description: Double-buffered 12-bit Multiplying Dac
• Manufacturer: Exar Corporation

Figure 2. Bipolar Operation
a 28–pin SOIC. The HS3120 is available in
commercial and military temperature ranges,
packaged in a 28–pin side–brazed DIP. For
product processed and screened to the require-
ments of MIL–M–38510 and MIL–STD–883C,
please consult the factory (HS3120B only).
APPLICATIONS INFORMATION
Unipolar Operation
Figure 1 shows the interconnections for unipo-
lar operation. Connect I
diagram. Tie I
(Pin 1) to Ground (Pin 8). To maintain specified
linearity, external amplifiers must be zeroed.
This is best done with V
the DAC register loaded with all bits at zero,
adjust R
SIGNAL PROCESSING EXCELLENCE
LDAC
MBE
HBE
LBE
CE
DIGITAL
INPUTS
Corporation
V REF
OS
for V
SP7512
V DD2
O2
V SS
OUT
(Pin 7), FB
V DD1
400
V SS1
FB 1
I O1
FB 4
FB 3
I O2
LDTR
= 0V
+15V
REF
O1
R OS2
1K
+
-
N.C.
N.C.
A 2
and FB
set to zero and, with
-15V
3
4K
3K
(Pin 3), and FB
20K
4M
1
ADJUSTMENT
RANGE 0.2%
A 1 , A 2 , LF411ACN
as shown in
+15V
R OS1
+
-
A
1
V OUT1
V OUT
4
Table 1. Transfer Function
Bipolar Operation
Figure 2 shows the interconnections for bipolar
operation. Connect I
shown in diagram. Tie LDTR to I
tain specified linearity, external amplifiers must
be zeroed. This is best done with V
and, the DAC register loaded with 10...0 (MSB
= 1), set R
V
Grounding
Connect all GND pins to system analog ground
and tie this to digital ground. All unused input
pins must be grounded.
BINARY INPUT UNIPOLAR OUTPUT BIPOLAR OUTPUT
OUT
111...111
100...001
100...000
011...111
000...000
TRANSFER FUNCTION (N=12)
= 0V.
OS2
for V
–V
–V
–V
REF
REF
OUT1
REF
–V
(1/2 + 2
(1/2 – 2
O1
(1 – 2
REF
0
, I
= 0V. Then set R
/2
O2
–N
–N
–N
)
, FB
)
)
–V
1
, FB
–V
REF
V
REF
O2
REF
REF
(1 – 2
. To main-
V
set to zero
(2
3
(2
0
REF
, FB
–(N – 1)
–(N – 1)
OS1
–(N – 1)
)
117
4
)
for
)
as