AD847 Analog Devices, AD847 Datasheet - Page 12

• Manufacturer Part Number: AD847
• Description: High Speed, Low Power Monolithic Op Amp
• Manufacturer: Analog Devices

Specifications of AD847

• -3db Bandwidth: 50MHz
• Slew Rate: 300V/µs
• Vos: 500µV
• Ib: 3.3µA
• # Opamps Per Pkg: 1
• Input Noise (nv/rthz): 15nV/rtHz
• Vcc-vee: 9V to 36V
• Isy Per Amplifier: 4.8mA
• Packages: DIP,SOIC

All brand or product names mentioned are trademarks or registered trademarks of their respective holders.
AD847
HIGH SPEED DAC BUFFER
The wide bandwidth and fast settling time of the AD847 makes
it a very good output buffer for high speed current-output D/A
converters like the AD668. As shown in Figure 27, the op amp
establishes a summing node at ground for the DAC output. The
output voltage is determined by the amplifier’s feedback resistor
(4.19±0.25)
0.165±0.01
(3.18)
0.125
PIN 1
MIN
0.018±0.003
(0.46±0.08)
Mini-DIP (N-8) Package
8
1
0.39 (9.91) MAX
0.011±0.003
0.30 (7.62)
15
(0.28±0.08)
0
(2.54)
°
0.10
BSC
°
REF
0.033
(0.84)
NOM
4
5
0.035±0.01
(0.89±0.25)
(6.35)
0.25
SEATING
PLANE
0.18±0.03
(4.57±0.76)
(7.87)
0.31
DIGITAL
INPUTS
10
11
12
1
2
4
5
9
3
6
7
8
MSB
LSB
AD668
Figure 27. High Speed DAC Buffer
Dimensions shown in inches and (mm).
0.200 (5.08)
0.125 (3.18)
REFCOM
REFIN2
THCOM
REFIN1
R
ACOM
LCOM
OUTLINE DIMENSIONS
(5.08)
0.200
IBPO
MAX
LOAD
I
0.005 (0.13) MIN
PIN 1
VTH
V
OUT
V
Cerdip (Q-8) Package
CC
EE
0.023 (0.58)
0.014 (0.36)
23
20
22
21
19
18
17
16
15
14
13
24
8
1
0.405 (10.29) MAX
+15V
0.320 (8.13)
0.290 (7.37)
15
0.015 (0.38)
0.008 (0.20)
0
0.100
(2.54)
BSC
–12–
100pF
0.1 F
10 F
ANALOG GROUND PLANE
0.055 (1.40) MAX
0.070 (1.78)
0.030 (0.76)
(10.24 V for a 1 k resistor). Note that since the DAC gener-
ates a positive current to ground, the voltage at the amplifier
output will be negative. A 100
noninverting amplifier input and ground minimizes the offset
effects of op amp input bias currents.
0.1 F
100
1k
4
5
10k
0.310 (7.87)
0.220 (5.59)
0.060 (1.52)
0.015 (0.38)
TO ANALOG
GROUND PLANE
SEATING
PLANE
10 F
0.150
(3.81)
MIN
AD847
+5V
–15V
+
–
1k
1V NOMINAL
REFERENCE INPUT
ANALOG
SUPPLY
GROUND
ANALOG
OUTPUT
0.098 (0.2482)
0.075 (0.1905)
Small Outline (R-8) Package
0.010 (0.25)
0.004 (0.10)
0.244 (6.20)
0.228 (5.79)
0.020 (0.051) x 45
CHAMF
PIN 1
8
0
series resistor between the
°
°
1
0.050
(1.27)
8
BSC
10
0
0.197 (5.01)
0.189 (4.80)
0.150 (3.81)
0.190 (4.82)
0.170 (4.32)
°
°
°
0.019 (0.48)
0.014 (0.36)
4
5
0.030 (0.76)
0.018 (0.46)
0.102 (2.59)
0.094 (2.39)
0.157 (3.99)
0.150 (3.81)
0.090
(2.29)
REV. F