Document
Philips Semiconductors Linear Products
Product specification
8-bit multiplying D/A converter
MC1508-8/1408-8
DESCRIPTION
The MC1508/MC1408 series of 8-bit monolithic digital-to-analog converters provide high-speed performance with low cost. They are designed for use where the output current is a linear product of an 8-bit digital word and an analog reference voltage
PIN CONFIGURATIONS
F, N Packages
NC GND VEE 1 2 3 4 5 6 7 8 16 COMPEN 15 VREF(–) 14 V REF(+) 13 V CC 12 A 8 11 A7 10 A6 9 A5 LSB
FEATURES
• Fast settling time — 70ns (typ) • Relative accuracy ±0.19% (max error) • Non-inverting digital inputs are TTL and CMOS compatible • High-speed multiplying rate 4.0mA/µs (input slew) • Output voltage swing +0.5V to –5.0V • Standard supply voltages +5.0V and –5.0V to –15V • Military qualifications pending
APPLICATIONS
IO MSB A1 A2 A3 A4
D Package1
V+ 1 VREF(+) 2 16 A8 15 A7 14 A6 13 A5 12 A4 11 A3 TOP VIEW 10 A2 9 A1 MSB LSB
VREF(–) 3 COMPEN NC GND V– IO 4 5 6 7 8
• Tracking A-to-D converters • 2 1/2-digit panel meters and DVMs • Waveform synthesis • Sample-and-Hold • Peak detector • Programmable gain and attenuation • CRT character generation • Audio digitizing and decoding • Programmable power supplies • Analog-digital multiplication • Digital-digital multiplication • Analog-digital division • Digital addition and subtraction • Speech compression and expansion • Stepping motor drive modems • Servo motor and pen drivers
ORDERING INFORMATION
DESCRIPTION 16-Pin Ceramic Dual In-Line Package (CERDIP) 16-Pin Ceramic Dual In-Line Package (CERDIP) 16-Pin Plastic Dual In-Line Package (DIP) 16-Pin Small Outline (SO) Package
NOTE: 1. SO and non-standard pinouts.
TEMPERATURE RANGE -55 to +125°C 0 to +70°C 0 to +70°C 0 to +70°C
ORDER CODE MC1508-8F MC1408-8F MC1408-8N MC1408-8D
DWG # 0582B 0582B 0406C 0005D
August 31, 1994
737
853-0935 13721
Philips Semiconductors Linear Products
Product specification
8-bit multiplying D/A converter
MC1508-8/1408-8
BLOCK DIAGRAM
MSB A1 5 A2 6 A3 7 A4 8 A5 9 A6 10 A7 11 LSB A8 12 IO CURRENT SWITCHES 4
R-2R LADDER VREF (+) 14 15 (–) VREF
BIAS CURRENT
2 GND
13 REFERENCE CURRENT AMPLIFIER VCC
16 COMPEN VEE 3
NPN CURRENT SOURCE PAIR
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
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, whi.