MP7628
5 V CMOS
Quad Multiplying 8-Bit
Digital-to-Analog Converter
FEATURES
APPLICATIONS
• Readback Capability for all DACs
• On-Chip Latches for All DACs
• Linearity Grades to +1/8 LSB
• Single Supply Voltage (5 Volt)
• DACs Matched to 1%
• Four Quadrant Multiplication
• Microprocessor TTL/CMOS Compatible
• Latch-Up Free
• Microprocessor Controlled Gain and Attenuation
Circuits
• Microprocessor Controlled/Programmable
Power Supplies
• Hardware Redundant Applications Requiring
Data Readback
• Dual Version: MP7529B
Data is transferred into any of the four DAC data latches via
common 8-bit TTL/CMOS compatible input port. Control inputs
DS1, DS2 and A/B determine which DAC is to be loaded. The
MP7628’s load cycle is similar to the write cycle of a random ac-
cess memory and the device is bus compatible with most 8-bit
microprocessors.
GENERAL DESCRIPTION
The MP7628 is a quad 8-bit Digital-to-Analog Converter de-
signed using a decoded DAC architecture featuring excellent
DAC-to-DAC matching and guaranteed monotonicity.
Separate on-chip latches are provided for each DAC to allow
easy microprocessor interface.
The device operates at +5 V power supply and dissipates
less than 5mW.
The readback function allows the user to poll or read the data
latches, eliminating the need for storing information in RAM. In
the event the microprocessor power supply is interrupted, it can
poll the DACs to establish the last known system state.
All DACs offer excellent four quadrant multiplication charac-
teristics with a separate reference input and feedback resistor
for each DAC.
SIMPLIFIED BLOCK DIAGRAM
V
DD
V
REFB
V
REFA
R
FBA
LATCH A
R
FB
DAC A
I
OUT1A
THREE-STATE
BUFFER
I
I
/
DB0
OUT2A
OUT2B
BI-
DIRECTIONAL
LINE
(LSB)
DATA BUS
DB7
(MSB)
LATCH B
DRIVER
DAC B
DAC C
I
OUT1B
THREE-STATE
BUFFER
R
R
FB
FB
R
R
FBB
FBC
LATCH C
I
OUT1C
THREE-STATE
BUFFER
I
I
/
A/B
OUT2C
OUT2D
CONTROL
LOGIC
R/W
LATCH D
DAC D
DS1
DS2
I
OUT1D
THREE-STATE
BUFFER
R
FB
R
FBD
GND
V
REFC
V
REFD
Rev. 2.00
1