AD7839
–12–
REV. 0
C3168–2–4/99
PRINTED IN U.S.A.
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
44-Lead MQFP (S-44)
0.548 (13.925)
0.546 (13.875)
TOP VIEW
(PINS DOWN)
1
33
34
44
11
12
23
22
0.033 (0.84)
0.029 (0.74)
0.398 (10.11)
0.390 (9.91)
0.016 (0.41)
0.012 (0.30)
0.083 (2.11)
0.077 (1.96)
0.040 (1.02)
0.032 (0.81)
0.040 (1.02)
0.032 (0.81)
SEATING
PLANE
0.096 (2.44)
MAX
0.037 (0.94)
0.025 (0.64)
8°
0.8°
GND
V
DD
8/10-BIT
DAC
GND
V
DD8/10-BIT
DAC
LOGIC LEVEL
SHIFT
+5V
ⴚ5V
SCLK
D IN
FSIN/CS
SCLK
D IN
FSIN/CS
0V TO +5V
0V TO ⴚ5V
V
REF
(+)AB
A0, A1, A2
V
OUT
A
V
OUT
A
V
OUT
B
V
OUT
B
V
REF
(ⴚ)AB
AD7839*
GND
DATA BUS
ADDR
DECODER
ADDR BUS
SDATA
SCLK
DATA BUS
CONTROLLER
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 22. Programmable Reference Generation for the AD7839
these DACs can be operated with supplies of 0 V and –5 V, with
the V
DD
pin connected to 0 V and the GND pin connected to
–5 V. Now these can be used to provide the negative reference
voltages for the V
REF
(–) inputs on the AD7839. However, the
digital signals driving the DACs need to be level-shifted from
the 0 V to +5 V range to the –5 V to 0 V range. Figure 22 shows
a typical application circuit to provide programmable reference
capabilities for the AD7839.
