DA8444A.005
May 31, 1996
MAS8444A
OCTAL 6-BIT TRIMMER IC
• Eight discrete DACs
2
• I C-bus slave receiver
• Voltage output
DESCRIPTION
The MAS8444a comprises eight digital to analog
converters (DACs) each controlled by a two-wire I
2
C
bus. The DACs are individually programmed using an
6-bit word to select an output from one of 64 voltage
steps. The maximum output voltage of all DACs is set
by Vmax. At power-on all outputs are set to their lowest
value. The I
2
C-bus slave receiver has 3 programmable
address pins (2 in the SO16 package).
FEATURES
• Rail to rail output stages
• Octal 6-bit DACs on a single monolithic chip
• Power supply range from +5V to +12V
• -25 C to +85 C temperature range
• 16-pin PDIL and SO package
• pin to pin compatibility with TDA8444
APPLICATION
• Trimmer replacement
• Automatic gain control
• High resolution monitors
BLOCK DIAGRAM
¡
SDA 3
SCL 4
A0 5
A1 6
A2 7
I C Bus
Slave
Receiver
2
6-BIT DAC
DAC7
6-BIT DAC
DAC6
DAC5
6-BIT DAC
6-BIT DAC
6-BIT DAC
6-BIT DAC
DAC4
DAC3
DAC2
DAC1
Vmax 2
Reference
Voltage
Generator
6-BIT DAC
6-BIT DAC
DAC0
1
8
VDD GND
1
DA8444A.005
May 31, 1996
PIN CONFIGURATION
PDIP 16
MAS8444AN
VDD 1
Vmax 2
SDA 3
SCL 4
A0 5
A1 6
A2 7
GND 8
16 DAC7
15 DAC6
14 DAC5
13 DAC4
12 DAC3
11 DAC2
10 DAC1
9 DAC0
SO16
MAS8444AS
VDD
Vmax
SDA
SCL
NC
A0
A1
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
DAC7
DAC6
DAC5
DAC4
DAC3
DAC2
DAC1
DAC0
PIN DESCRIPTION
Pin name
Pin no.
PDIP1
6
VDD
Vmax
SDA
SCL
A
0
A
1
A
2
GND
DAC0
DAC1
DAC2
DAC3
DAC4
DAC5
DAC6
DAC7
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
SO16
1
2
3
4
6
7
NC
8
9
10
11
12
13
14
15
16
P
I
I/O
I
I
I
I
G
O
O
O
O
O
O
O
O
Positive supply voltage
Control input for DAC maximum output voltage
I
2
C bus serial data input/output
I
2
C bus serial data clock
Programmable address bits for I
2
C bus slave receiver
Programmable address bits for I
2
C bus slave receiver
Programmable address bits for I
2
C bus slave receiver
Ground
Analog voltage output
Analog voltage output
Analog voltage output
Analog voltage output
Analog voltage output
Analog voltage output
Analog voltage output
Analog voltage output
I/O
Function
2
DA8444A.005
May 31, 1996
ABSOLUTE MAXIMUM RATINGS
(conditions)
Parameter
Supply Voltage
Supply current
I
2
C-bus line voltage
Input voltage
Output voltage
Maximum current on any pin
(except pins 1 and 8)
Total power dissipation
Operating ambient temperature
range
Storage temperature range
Symbol
VDD
IDD
V(3),V(4)
Vin
Vo
Imax
Ptot
Tamb
Tstg
Conditions
Min
-0.5
-10
-0.5
-0.5
-0.5
Max
18
40
5.9
VDD+0.5
Unit
V
10
500
-20
-65
+70
+150
mA
mW
o
o
Parameter
Supply Voltage
Supply current
Voltage level from power
Total power dissipation
Symbol
VDD
IDD
V1
Ptot
Conditions
No loads
No loads, Vmax=VDD
ELECTRICAL CHARACTERISTICS
Inputs
SDA, SCL input (pins 3, 4)
(All voltages are with respect to GND; Tamb = 25
o
C; VDD = 12V unless otherwise specified)
Parameter
Input voltage range
Input low voltage
Input high voltage
Input current low
Input current high
Symbol
V
I
V
IL
V
IH
I
IL
V
IH
Conditions
Min
0
3.0
V(3),V(4) = -0.3V
V(3),V(4) = 6.0V
-10
+10
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Min
4.5
6.0
1
Typ
12
Max
Unit
V
mA
V
mW
13.2
17.0
4
10.0
120
Typ
Max
5.5
1.0
Unit
V
V
V
µA
µA
3
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VDD+0.5
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V
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DA8444A.005
May 31, 1996
ELECTRICAL CHARACTERISTICS
Address Input (pins 5, 6, 7)
(All voltages are with respect to GND; Tamb = 25
o
C; VDD = 12V unless otherwise specified)
Parameter
Input voltage range
Input low voltage
Input high voltage
Input current low
Input current high
Symbol
V
I
V
IL
V
IH
I
IL
I
IH
Conditions
Min
0
Typ
Max
VDD
1.0
Unit
V
V
V
2.2
-7
-10
1
µA
µA
(All voltages are with respect to GND; Tamb = 25
o
C; VDD = 12V unless otherwise specified)
Parameter
Input current
Effective voltage range
Symbol
I
2
Vmax
Conditions
Min
Typ
7
Max
10
VDD-2.0
Unit
µA
V
1.0
Parameter
Output voltage range
Minimum output voltage
Max output voltage
Temperature coefficient
Gain error
Output impedance
Output capacitive load
note 1: Vomax = Vmax + Vo(00)
Parameter
Output voltage low
Sink current
DAC Outputs (pin 9 to 16)
(All voltages are with respect to GND; Tamb = 25
o
C; VDD = 12V unless otherwise specified)
Symbol
Vo
Vomin
Vomax
Conditions
Min
0.1
Typ
Max
VDD-0.5
Unit
V
V
V
data = 00; Io = +2mA
data = 3f; Io = -2mA; Vmax =
data = 3f; Io = -2mA;
0.1
10
0.4
11.1
see note 1
0.5
11.5
Tc
data = 3F
Zo
Co
data = 1F; -2mA < Io < +2mA
50
1
2
mV/K
%
2
nF
SDA Output (pin 3)
(All voltages are with respect to GND; Tamb = 25
o
C; VDD = 12V unless otherwise specified)
Symbol
V
OL
Isink
Conditions
I
3
= 3.0 mA
Min
Typ
0.2
Max
0.4
Unit
V
mA
3
8
4
DA8444A.005
May 31, 1996
ELECTRICAL CHARACTERISTICS
Linearity
CONT.
(All voltages are with respect to GND; Tamb = 25
o
C; VDD = 12V unless otherwise specified)
Parameter
Differential nonlinearity
Integral nonlinearity
Symbol
DNL
INL
Conditions
Io = -2mA; Vmax = VDD
Io = -2mA; Vmax = VDD
Min
-0.5
-0.5
Typ
0.1
0.1
Max
0.5
0.5
Unit
LSB
LSB
FUNCTIONS
S
I
2
C - bus
The MAS8444A I
2
C-bus interface is a receiver-only slave. Data is accepted from the I
2
C-bus in the following format.
0 1 0 0 A2 A1 A0 0
Address byte
A
I3 I2 I1 I0 SD SC SB SA
Instruction byte
A
D7 D6 D5 D4 D3 D2 D1 D0
First data byte
A
P
S
P
A
Start condition
Stop condition
Acknowledgement
A2, A1, A0
I3, I2, I1, I0
SD, SC, SB, SA
D7, D6, D5, D4, D3, D2, D2, D1, D0
programmable address bits
instruction bits
sub-address bits
data bits
I
2
C - bus timing
Bit Transfer on the I C-bus
SDA
2
SCL
Data line
stable
(data valid)
Change
of data
allowed
Complete Data Transfer
SDA
SCL
S
Start
condition
1-7
8
9
1-7
8
9
1-7
8
9
P
Address
R/W
Ack
Data
Ack
Data
Ack
Stop
condition
5
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