DAC8512FS Analog Devices Inc, DAC8512FS Datasheet - Page 5

• Manufacturer Part Number: DAC8512FS
• Description: IC DAC 12BIT 5V COMPLETE 8-SOIC
• Manufacturer: Analog Devices Inc

Specifications of DAC8512FS

• Data Interface: Serial
• Rohs Status: RoHS non-compliant
• Settling Time: 16µs
• Number Of Bits: 12
• Number Of Converters: 1
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 2.5mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Resolution (bits): 12bit
• Sampling Rate: 62.5kSPS
• Input Channel Type: Serial
• Supply Voltage Range - Analog: 4.75V To 5.25V
• Supply Current: 1.5mA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

REV. A
Pin
1
2
3
4
5
6
7
8
Name Description
V
CS
CLK
SDI
LD
CLR
GND Analog ground for the DAC. This also serves as the
V
CLK
V
SDI
DD
CS
DD
OUT
1
2
4
3
CLK
SUBSTRATE IS COMMON WITH V
NUMBER OF TRANSISTORS : 642
DIE SIZE: 0.055 inch
(Not to Scale)
CS
SO-8
DAC8512
Active low input which writes the serial register data
into the DAC register. Asynchronous input.
Active low digital input that clears the DAC register to
zero, setting the DAC to minimum scale. Asynchronous
input.
digital logic ground reference voltage.
Voltage output from the DAC. Fixed output voltage
range of 0 V to 4.095 V with 1 mV/LSB. An internal
temperature stabilized reference maintains a fixed
full-scale voltage independent of time, temperature and
power supply variations.
TOP VIEW
Positive Supply. Nominal value +5 V,
Chip Select. Active low input.
Clock input for the internal serial input shift register.
Serial Data Input. Data on this pin is clocked into the
internal serial register on positive clock edges of the
CLK pin. The Most Significant Bit (MSB) is loaded
first.
DICE CHARACTERISTICS
2
3
PIN CONFIGURATIONS
PIN DESCRIPTIONS
V
1
DD
8
7
6
5
SDI
4
V
GND
CLR
LD
OUT
0.106 inch; 5830 sq mils
CLK
V
SDI
CS
DD
P-DIP-8 & Cerdip-8
1
2
4
3
V
LD
OUT
5
8
DD
(Not to Scale)
DAC8512
TOP VIEW
.
7
7
6
GND
GND
CLR
5%.
7
6
5
8
V
GND
CLR
LD
OUT
–5–
OPERATION
The DAC8512 is a complete ready to use 12-bit digital-to-analog
converter. It contains a voltage-switched, 12-bit, laser-trimmed
DAC, a curvature-corrected bandgap reference, a rail-to-rail
output op amp, a DAC register, and a serial data input register.
The serial data interface consists of a CLK, serial data in (SDI),
and a load strobe (LD). This basic 3-wire interface offers maxi-
mum flexibility for interface to the widest variety of serial data
input loading requirements. In addition a CS select is provided
for multiple packaging loading and a power on reset CLR pin to
simplify start or periodic resets.
D/A CONVERTER SECTION
The DAC is a 12-bit voltage mode device with an output that
swings from GND potential to the 2.5 volt internal bandgap
voltage. It uses a laser trimmed R-2R ladder which is switched
by N channel MOSFETs. The output voltage of the DAC has a
constant resistance independent of digital input code. The DAC
output is internally connected to the rail-to-rail output op amp.
AMPLIFIER SECTION
The DAC’s output is buffered by a low power consumption pre-
cision amplifier. This amplifier contains a differential PNP pair
input stage which provides low offset voltage and low noise, as
well as the ability to amplify the zero-scale DAC output volt-
ages. The rail-to-rail amplifier is configured in a gain of 1.6384
(= 4.095 V/2.5 V) in order to set the 4.095 volt full-scale output
(1 mV/LSB). See Figure 3 for an equivalent circuit schematic of
the analog section.
The op amp has a 16 s typical settling time to 0.01%. There
are slight differences in settling time for negative slowing signals
vs. positive. See the oscilloscope photos in the typical perfor-
mances section of this data sheet.
Figure 3. Equivalent DAC8512 Schematic of Analog
Portion
REFERENCE
BANDGAP
2.5V
BUFFER
SWITCHES
N-CH FET
VOLTAGE SWITCHED 12-BIT
R-2R D/A CONVERTER
SPDT
2R
2R
2R
2R
2R
R
R
DAC8512
AV = 4.095/2.5
R1
= 1.638V/V
RAIL-TO-RAIL
OUTPUT
AMPLIFIER
R2
V
OUT