AD8804AR Analog Devices Inc, AD8804AR Datasheet - Page 14

• Manufacturer Part Number: AD8804AR
• Description: IC DAC 8BIT 12CH W/SD 20-SOIC
• Manufacturer: Analog Devices Inc
• Series: TrimDAC®r

Specifications of AD8804AR

• Rohs Status: RoHS non-compliant
• Settling Time: 600ns
• Number Of Bits: 8
• Data Interface: Serial
• Number Of Converters: 12
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 60µW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-SOIC (7.5mm Width)

AD8802/AD8804
TMP14, and makes the necessary adjustments to the AD8802/
AD8804 before shutting down again. The 80CL51 consumes
only 50 A when operating at 32 kHz, in which case there
would be no need for the TLC555, which consumes 1 mW typ.
12 Channel Programmable Voltage Controlled Amplifier
The SSM2018T is a trimless Voltage Controlled Amplifier
(VCA) for volume control in audio systems. The SSM2018T is
the first professional quality audio VCA in the marketplace that
does not require an external trimming potentiometer to mini-
mize distortion. The TrimDAC shown in Figure 28 is not being
used to trim distortion, but rather to control the gain of the am-
plifier. In this configuration up to twelve SSM2018T can be
digitally controlled. (Please refer to the SSM2018T data sheet
for more specifications and applications information.)
0.01µF
INPUTS
USER
1µF
1µF
+15V
18k
18k
3
P0.0
P0.7
TLC555
OUT
P1.0/INT2
80CL51 µC
47pF
GND
+5V
V
CC
TO 8 MORE CHANNELS
1
2
3
4
5
6
7
8
TRIG
THR
DIS
P2.1
P2.2
P2.3
P2.4
RS
P2.0
P3.2
P3.1
P3.0
P3.3
SSM2018T
Figure 27. Temperature Sensor Array with Programmable Setpoints
Figure 28. 12-Channel Programmable Voltage Controlled Amplifier
18k
50pF
3
ARRAY IF NEEDED
TO 2nd AD8802/4
16
15
14
13
12
11
10
9
NC
150k
R
O
+V
–15V
O4–O12
V
OUT
SDI
SHDN
CS
CLK
O2
AD8802/4
O3
09–12
05–8
GND
0 TO 40dB GAIN
V
OPTIONAL FOR
O1
O2
O3
O4
OP420A
DD
1.2V
–14–
V
4
4
REFH
+15V
0.1µF
The gain of the SSM2018T is controlled by the voltage at Pin 11.
For maximum attenuation of –100 dB a control signal of 3.0 V
typ is necessary. The control signal has a scale of –30 mV/dB
centered around 0 dB gain for 0 V of control voltage, therefore,
for a maximum gain of 40 dB a control voltage of –1.2 volts is
necessary. Now notice that the normal +5 V to GND voltage
range of the AD8802/AD8804 does not cover the 3.0 V to
–1.2 V operational gain control range of the SSM2018T. To
cover the operating gain range fully and not exceed the maxi-
mum specified power supply rating requires the O1 output of
AD8802/AD8804 to be level shifted down. In Figure 28, the
level shifting is accomplished by a Zener diode and 1/4 of an
OP420 quad op amp. For applications that require only
50k
TO 2nd TEMP SENSOR
IF NEEDED
TO 3rd TEMP SENSOR
IF NEEDED
TO µC
10µF
3
+5V
O1
CS
CLK
SDI
O2–
O12
AD8802/4
(AD8804
V
V
ONLY)
REFH
GND
REFL
V+
SET 1
SET 2
SET 3
SET 4
SLEEP
2.5 V
TMP14
REF
1µF
TRIP 1
TRIP 2
TRIP 3
TRIP 4
GND
HYS
V +
OUT
REF195
GND
0.1µF
+5V
IN
+15V
REV. 0