MC1408-8D Philips Semiconductors, MC1408-8D Datasheet - Page 2

• Manufacturer Part Number: MC1408-8D
• Description: 8-bit multiplying D/A converter
• Manufacturer: Philips Semiconductors

1. Derate above 25 C, at the following rates: F package at 9.5mW/ C; N package at 11.6mW/ C; D package at 8.6mW/ C
Philips Semiconductors Linear Products
BLOCK DIAGRAM
CIRCUIT DESCRIPTION
The MC1508/MC1408 consists of a reference current amplifier, an
R-2R ladder, and 8 high-speed current switches. For many
applications, only a reference resistor and reference voltage need
be added.
The switches are non-inverting in operation; therefore, a high state
on the input turns on the specified output current component.
The switch uses current steering for high speed, and a termination
amplifier consisting of an active load gain stage with unity gain
ABSOLUTE MAXIMUM RATINGS
NOTES:
August 31, 1994
V
V
V
V
I
V
P
T
T
T
14
SOLD
A
STG
CC
EE
5
O
14
D
8-bit multiplying D/A converter
– V
, V
SYMBOL
15
12
Positive power supply voltage
Negative power supply voltage
Digital input voltage
Applied output voltage
Reference current
Reference amplifier inputs
Maximum power dissipation,
T
Lead soldering temperature (10 sec)
Operating temperature range
Storage temperature range
A
= 25 C (still-air)
F package
N package
D package
MC1508
MC1408
V
V
REF
14
REF
15
(+)
(–)
1
MSB
A
1
5
A
2
PARAMETER
R-2R LADDER
6
NPN CURRENT SOURCE PAIR
A
3
7
V
EE
CURRENT SWITCHES
A
3
4
8
738
A
5
feedback. The termination amplifier holds the parasitic capacitance
of the ladder at a constant voltage during switching, and provides a
low impedance termination of equal voltage for all legs of the ladder.
The R-2R ladder divides the reference amplifier current into
binarily-related components, which are fed to the remainder current
which is equal to the least significant bit. This current is shunted to
ground, and the maximum output current is 255/256 of the reference
amplifier current, or 1.992mA for a 2.0mA reference amplifier current
if the NPN current source pair is perfectly matched.
9
A
6
10
REFERENCE
CURRENT
AMPLIFIER
BIAS
CURRENT
A
7
11
A
LSB
8
12
V
COMPEN
GND
CC
–55 to +125
–5.2 to +18
V
-65 to +150
13
16
I
4
2
MC1508-8/1408-8
RATING
0 to V
EE
0 to +75
O
–16.5
1190
1450
1080
+5.5
300
300
5.0
to V
CC
CC
Product specification
UNIT
mW
mW
mW
mA
V
V
V
V
C
C
C
C
C