DAC1222 [TI]

10-Bit Binary Multiplying D/A Converter;
DAC1222
型号: DAC1222
厂家: TEXAS INSTRUMENTS    TEXAS INSTRUMENTS
描述:

10-Bit Binary Multiplying D/A Converter

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DAC1220  
www.ti.com...................................................................................................................................... SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009  
20-Bit, Low-Power  
Digital-to-Analog Converter  
Check for Samples: DAC1220  
1
FEATURES  
DESCRIPTION  
2
20-Bit Monotonicity Ensured Over –40°C to  
+85°C  
The DAC1220 is a 20-bit digital-to-analog (D/A)  
converter offering 20-bit monotonic performance over  
the specified temperature range. It utilizes  
delta-sigma technology to achieve inherently linear  
performance in a small package at very low power.  
The resolution of the device can be programmed to  
20 bits for Full-Scale, settling to 0.003% within 15ms  
typical, or 16 bits for Full-Scale, settling to 0.012%  
within 2ms max. The output range is two times the  
external reference voltage. On-chip calibration  
circuitry dramatically reduces low offset and gain  
errors.  
Low Power: 2.5mW  
Voltage Output  
Settling Time: 2ms to 0.012%  
Maximum Linearity Error: ±0.0015%  
On-Chip Calibration  
APPLICATIONS  
Process Control  
ATE Pin Electronics  
Closed-Loop Servo Control  
Smart Transmitters  
Portable Instruments  
The DAC1220 features  
a
synchronous serial  
interface; in single-converter applications, the serial  
interface can be accomplished with just two wires,  
allowing low-cost isolation. For multiple converters, a  
CS signal allows for selection of the appropriate D/A  
converter.  
The DAC1220 has been designed for closed-loop  
control applications in the industrial process control  
market and high-resolution applications in the test  
and measurement market. It is also ideal for remote  
applications, battery-powered instruments, and  
isolated systems. The DAC1220 is available in an  
SSOP-16 package.  
XIN  
XOUT  
VREF  
AVDD  
AGND  
Clock Generator  
Microcontroller  
C1  
2nd−Order  
∆Σ  
Modulator  
1st−Order  
Switched  
Capacitor Filter  
2nd−Order  
Continuous  
Time Post Filter  
Instruction Register  
Command Register  
Data Register  
VOUT  
C2  
Offset Register  
Full−Scale Register  
Modulator Control  
Serial  
Interface  
SDIO  
SCLK  
CS  
DVDD  
DGND  
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas  
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.  
2
All trademarks are the property of their respective owners.  
PRODUCTION DATA information is current as of publication date.  
Products conform to specifications per the terms of the Texas  
Instruments standard warranty. Production processing does not  
necessarily include testing of all parameters.  
Copyright © 1998–2009, Texas Instruments Incorporated  
 
DAC1220  
SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009...................................................................................................................................... www.ti.com  
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with  
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.  
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more  
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.  
PACKAGE/ORDERING INFORMATION  
For the most current package and ordering information see the Package Option Addendum at the end of this  
document, or see the TI web site at www.ti.com.  
ABSOLUTE MAXIMUM RATINGS(1)  
Over operating free-air temperature range (unless otherwise noted).  
DAC1220  
±0.3  
UNIT  
V
AVDD to DVDD  
AVDD to AGND  
–0.3 to +6  
–0.3 to +6  
±0.3  
V
DVDD to DGND  
V
AGND to DGND  
V
VREF voltage to AGND  
Digital input voltage to DGND  
Digital output voltage to DGND  
Package power dissipation  
Maximum junction temperature (TJmax)  
Thermal resistance, θ JA  
Lead temperature (soldering, 10s)  
+2.0 to +3.0  
–0.3 to DVDD + 0.3  
–0.3 to DVDD + 0.3  
(TJmax – TA) / θ JA  
+150  
V
V
V
W
°C  
°C/W  
°C  
SSOP-16  
200  
+300  
(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings  
only, and functional operation of the device at these or any other conditions beyond those indicated under the Electrical Characteristics  
is not implied. Exposure to absolute maximum rated conditions for extended periods may affect device reliability.  
2
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Copyright © 1998–2009, Texas Instruments Incorporated  
Product Folder Link(s): DAC1220  
DAC1220  
www.ti.com...................................................................................................................................... SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009  
ELECTRICAL CHARACTERISTICS  
All specifications at TMIN to TMAX, AVDD = DVDD = +5V, fXIN = 2.5MHz, VREF = +2.5V, and 16-bit mode, unless otherwise noted.  
DAC1220E  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
UNIT  
ACCURACY  
Monotonicity  
Monotonicity  
Linearity error  
Unipolar offset error and gain error(2)  
Unipolar offset error drift(3)  
Bipolar zero offset error(2)  
Bipolar zero offset drift(3)  
Gain error(2)  
16  
20  
Bits  
Bits  
20-bit mode  
±15(1)  
±60  
ppm of FSR  
ppm of FSR  
ppm/°C  
1
±15  
1
VOUT = VREF  
ppm of FSR  
ppm/°C  
±150  
ppm of FSR  
ppm/°C  
Gain error drift(3)  
2
Power-supply rejection ratio (PSRR)  
ANALOG OUTPUT  
at DC, dB = –20log(ΔVOUT/ΔVDD  
)
60  
dB  
Output voltage(4)  
0
2 × VREF  
0.5  
V
Output current  
mA  
pF  
Capacitive load  
500  
±20  
Short-circuit current  
mA  
Short-circuit duration  
DYNAMIC PERFORMANCE  
Settling time(5)  
GND or VDD  
Indefinite  
To ±0.012%  
20-bit mode, to ±0.003%  
0.1Hz to 10Hz  
1.8  
15  
1
2
ms  
ms  
Output noise voltage  
REFERENCE INPUT  
Input voltage  
μVRMS  
2.25  
2.5  
2.75  
V
Input impedance  
DIGITAL INPUT/OUTPUT  
Logic family  
100  
kΩ  
TTL-compatible CMOS  
Logic levels (all except XIN  
)
VIH  
2.0  
DVDD + 0.3  
0.8  
V
V
VIL  
–0.3  
3.6  
VOH  
IOH = –0.8mA  
IOL = 1.6mA  
V
VOL  
0.4  
±10  
2.5  
V
Input-leakage current  
μA  
MHz  
XIN frequency range (fXIN  
)
0.5  
Offset binary two's complement  
or straight binary  
Data format  
User-programmable  
POWER-SUPPLY REQUIREMENTS  
Power-supply voltage  
Supply current  
4.75  
5.25  
V
Analog current  
360  
140  
460  
μA  
μA  
μA  
Digital current  
Analog current  
20-bit mode  
(1) Valid from AGND + 20mV to AVDD – 20mV.  
(2) Applies after calibration.  
(3) Recalibration can remove these errors.  
(4) Ideal output voltage; does not take into account gain and offset error.  
(5) Valid from AGND + 20mV to AVDD – 20mV. Outside of this range, settling time can be twice the value indicated.  
For 16-bit mode, C1 = 2.2nF, C2 = 0.22nF; for 20-bit mode, C1 = 10nF, C2 = 3.3nF.  
Copyright © 1998–2009, Texas Instruments Incorporated  
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DAC1220  
SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009...................................................................................................................................... www.ti.com  
ELECTRICAL CHARACTERISTICS (continued)  
All specifications at TMIN to TMAX, AVDD = DVDD = +5V, fXIN = 2.5MHz, VREF = +2.5V, and 16-bit mode, unless otherwise noted.  
DAC1220E  
PARAMETER  
POWER-SUPPLY REQUIREMENTS, continued  
Digital current  
CONDITIONS  
MIN  
TYP  
MAX  
UNIT  
20-bit mode  
140  
μA  
Power dissipation  
2.5  
3.0  
3.5  
mW  
mW  
mW  
20-bit mode  
Sleep mode  
0.45  
TEMPERATURE RANGE  
Specified performance  
–40  
+85  
°C  
DEVICE INFORMATION  
DVDD  
1
2
3
4
5
6
7
8
16 SCLK  
15 SDIO  
XOUT  
XIN  
14 CS  
DGND  
AVDD  
DNC  
DNC  
DNC  
13 AGND  
12 VREF  
11 VOUT  
10 C2  
DAC1220E  
9
C1  
PIN DESCRIPTIONS  
PIN  
1
NAME  
DVDD  
XOUT  
XIN  
DESCRIPTION  
Digital supply, +5V nominal  
2
System clock output (for crystal)  
System clock input  
3
4
DGND  
AVDD  
DNC  
DNC  
DNC  
C1  
Digital ground  
5
Analog supply, +5V nominal  
Do not connect  
6
7
Do not connect  
8
Do not connect  
9
Filter capacitor (see text)  
Filter capacitor (see text)  
Analog output voltage  
Reference input  
10  
11  
12  
13  
14  
15  
16  
C2  
VOUT  
VREF  
AGND  
CS  
Analog ground  
Chip-select input  
SDIO  
SCLK  
Serial data input/output  
Clock input for serial data transfer  
4
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Product Folder Link(s): DAC1220  
DAC1220  
www.ti.com...................................................................................................................................... SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009  
TYPICAL CHARACTERISTICS  
At TA = +25°C, AVDD = DVDD = +5.0V, fXIN = 2.5MHz, VREF = 2.5V, C1 = 2.2nF, and calibrated mode, unless otherwise  
specified.  
POWER-SUPPLY REJECTION RATIO  
vs  
FREQUENCY  
LARGE-SIGNAL SETTLING TIME  
60  
50  
40  
30  
20  
10  
0
5.0  
4.5  
4.0  
3.5  
3.0  
2.5  
2.0  
1.5  
1.0  
0.5  
0
400mVPP Ripple  
MidRange Output  
10  
100  
Frequency (Hz)  
1k  
10k  
0
1
2
3
4
Time (ms)  
Figure 1.  
Figure 2.  
OUTPUT NOISE VOLTAGE  
LINEARITY ERROR  
vs  
vs  
FREQUENCY  
CODE  
10k  
1k  
10  
8
−40°C  
+25°C  
+85°C  
6
100  
10  
1
4
2
0
2
10  
100  
1k  
10k  
100k  
1M  
0
10k  
20k  
30k  
40k  
Code  
50k  
60k  
70k  
Frequency (Hz)  
Figure 3.  
Figure 4.  
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DAC1220  
SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009...................................................................................................................................... www.ti.com  
THEORY OF OPERATION  
Self-Calibration System  
The DAC1220 is a monolithic 20-bit delta-sigma (ΔΣ)  
digital-to-analog converter (DAC) designed for  
applications requiring extremely high precision. The  
delta-sigma topology used in the DAC1220 ensures  
20-bit monotonicity over the industrial temperature  
range. The DAC1220 can also be operated in 16-bit  
mode, which gives a faster settling time at the  
expense of higher noise.  
The self-calibration system of the DAC1220  
measures the DAC output and calculates appropriate  
gain and offset calibration constants. The output  
changes during calibration, but can optionally be  
disconnected during the procedure.  
Offset calibration is performed by setting the DAC  
output voltage to mid-scale and repeatedly comparing  
the DAC output to the VREF voltage using an  
auto-zeroed comparator, which is re-zeroed after  
every comparison. The comparator results are  
recorded and averaged, two’s complement adjusted,  
and placed in the Offset Calibration Register.  
The core of the DAC1220 consists of an interpolation  
filter and a second-order delta-sigma modulator. The  
output of the modulator is passed to a first-order  
switched-capacitor filter in series with a second-order  
continuous-time filter, which generates the output  
voltage.  
Gain calibration is performed in a similar way, except  
To increase settling time, the DAC1220 can adjust its  
filter cutoff frequency when it detects a voltage output  
step of greater than approximately 40mV. This  
behavior can be disabled.  
that  
the  
correction  
is  
done  
against  
an  
internally-generated reference voltage, and the final  
register value is calculated differently. The Full-Scale  
Calibration Register result represents the gain code  
and is not two’s complement adjusted. Changing the  
Gain Register value can change the range of  
voltages that are output for the same digital codes,  
An onboard self-calibration facility compensates for  
internal offset and gain errors. Calibration values may  
be stored and loaded externally if desired.  
centered on VREF  
.
The DAC1220 can be put into a sleep mode, in which  
power consumption is cut by about 1/6 to  
approximately 0.45mW. In sleep mode, the output is  
disconnected.  
BASIC CONNECTIONS  
A schematic showing basic connections to the  
DAC1220 is given in Figure 5.  
The DAC1220 is controlled using a synchronous  
serial interface, using either two or three wires. The  
interface may be operated bidirectionally or  
unidirectionally; readback is optional.  
+5V  
µ
4.7 F  
Ceramic  
DVDD  
XOUT  
XIN  
SCLK  
SDIO  
CS  
SPI CLOCK  
12pF(1)  
12pF(1)  
SPI DATA  
2.5MHz  
From Chip Select or Ground  
DGND  
AVDD  
DNC  
DNC  
DNC  
AGND  
VREF  
VOUT  
C2  
+2.5V from  
Voltage Reference  
+5V  
VOUT  
(2)  
C2  
(2)  
C1  
µ
4.7 F  
Ceramic  
C1  
NOTES: (1) Depends on crystal and board layout. (2) See text for recommended values.  
Figure 5. DAC1220 Schematic  
6
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DAC1220  
www.ti.com...................................................................................................................................... SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009  
Output  
Digital Connections  
The output voltage range is nominally 0V to 2 × VREF  
.
The digital lines, except for the crystal oscillator lines,  
operate at TTL-compatible CMOS logic levels. They  
can be driven from 3.3V logic sources.  
It does not go below ground. The output amplifier is  
not designed for heavy loads; it can drive a maximum  
of 0.5mA. At power-on and during sleep mode, the  
amplifier is disconnected, so the output is high  
impedance.  
In noise-sensitive applications, it may be helpful to  
keep the level transition rates on the digital lines  
slow. Fast transitions can couple through the device  
to the output, causing noise. Rate limiting can be  
done with resistance or even an RC filter.  
The output is not fully linear to the rails; maximum  
linearity is specified from (AGND + 20mV) to (AVDD  
20mV). For linearity from 0–5V, AVDD can be  
increased to 5.02V or more, and AGND can be  
decreased to –20mV or less. As long as the specified  
operating limits are observed, this will not damage  
the device.  
Clock Oscillator  
The DAC1220 has a built-in crystal oscillator at pins  
XIN and XOUT. To use it, connect a crystal and load  
capacitors as shown in Figure 5.  
Filter Capacitors  
12pF load capacitors are shown in the schematic, but  
the correct value depends mainly on the crystal and  
layout, and not on the oscillator itself. Load  
The continuous-time output filter requires two external  
capacitors to operate. The recommended values of  
these capacitors depend on whether the DAC1220  
will be operated in 16-bit or 20-bit mode, and are  
shown in Table 1.  
capacitance  
affects  
startup  
time,  
oscillation  
frequency, and reliability. If startup is unreliable, try  
lowering the capacitor values. Remember that  
parasitic board and pin capacitance can be a  
significant portion of the crystal load capacitance.  
Table 1. Filter Capacitor Values  
When the crystal oscillator is operating, a sinusoidal  
signal of relatively low amplitude will be observed at  
both the XIN and XOUT pins.  
CAPACITOR  
16-BIT MODE  
2.2nF  
20-BIT MODE  
10nF  
C1  
C2  
0.22nF  
3.3nF  
The typical frequency to use with the DAC1220 is  
2.5MHz. Deviating too far from this may alter noise  
and settling time, as well as timing characteristics.  
The capacitors should be stable and high grade. Film  
types, or other capacitors designed for precision  
filtering, are strongly recommended. Low-quality  
capacitors will degrade performance significantly.  
Connecting an External Clock  
The C1 and C2 pins are very sensitive. It is critical to  
surround them with a guard ring at the reference  
voltage for best noise performance. See the Layout  
section for more information.  
An external clock signal can be connected at XIN. A  
CMOS or TTL logic signal can be used. If an external  
clock signal is used, XOUT should be left unconnected.  
In some cases, an RC filter on the clock line may  
reduce noise.  
Voltage Reference  
The voltage reference input is designed for +2.5V. At  
this voltage, the output will range from ground to  
approximately 5V, as noted above.  
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DAC1220  
SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009...................................................................................................................................... www.ti.com  
Serial Interface  
Most designs will use a single power supply for AVDD  
and DVDD. In these designs, the supplies ramp  
simultaneously, which is acceptable. In those designs  
that use separate sources for AVDD and DVDD, the  
two supplies must be sequenced properly. This is  
easily done using a Schottky diode, as shown in  
Figure 6. The diode ensures that DVDD will not  
exceed AVDD by more than a Schottky diode drop.  
The DAC1220 can be operated from most SPI  
peripherals, or it can be bit-banged.  
Note that if SDIO is operated bidirectionally, it may be  
necessary to place a pullup resistor on the line, so  
that the line will not be floating.  
The serial clock is limited to one-tenth of the master  
clock frequency. For a 2.4576MHz master clock, the  
serial clock may be no faster than 245.76kHz. The  
designer should bear this in mind, as it may prevent  
the DAC1220 from being shared with other SPI  
devices or placed on an SPI bus, which may run  
much faster.  
Brownouts and Power-On Reset  
The DAC1220 incorporates a power-on reset (POR)  
circuit. The circuit will trigger as long as the power  
supply ramps up at 50mV/ms or faster. If the power  
supply ramps more slowly than this, the POR may not  
trigger.  
If the DAC1220 is placed on a shared SPI bus, the  
chip-select line must be controlled; otherwise, it can  
be grounded.  
The DAC1220 does not have a brownout detector.  
The POR circuit will not retrigger unless the supply  
voltages have approached ground. Because of this, if  
the supply falls to a low voltage, it may corrupt the  
logic of the DAC1220, causing it to operate erratically  
or to fail entirely. It may be necessary to forcibly  
discharge the supply, since the DAC1220 may  
occasionally fail to detect the SCLK reset pattern in  
this condition.  
Although the SDIO line is bidirectional, it can be  
operated as an input only, as long as no register  
reads are performed. The DAC1220 can be operated  
without register reads, although for situations  
requiring high reliability, this is not recommended,  
since the device registers and operation cannot be  
directly verified.  
The SCLK reset pattern serves in place of a reset  
pin. See the SCLK Reset Pattern section for  
information.  
Power Supplies  
The DAC1220 has separate analog and digital power  
supply connections. Both are intended to operate at  
+5V.  
Supply Decoupling  
Both supply pins should be heavily decoupled at the  
device for best performance. A 10μF multi-layer  
ceramic capacitor can be used for this, or a tantalum  
capacitor in parallel with a small (0.1μF) ceramic  
capacitor can be used. Both capacitors, particularly  
the ceramic capacitor, should be placed as close to  
the pins as possible being decoupled.  
The digital supply must never exceed the analog  
supply by more than 300mV. If it does, the DAC1220  
may be permanently damaged. The analog supply  
may be greater than the digital supply without  
damage, however.  
5V  
Digital  
Supply  
DVDD  
5V  
Analog  
Supply  
AVDD  
Figure 6. Supply Sequence Protection  
8
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DAC1220  
www.ti.com...................................................................................................................................... SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009  
DIGITAL INTERFACE  
Timing  
The serial interface is synchronous and controlled by the SCLK input. The DAC1220 latches incoming bits on the  
falling edge of SCLK, and shifts outgoing bits on the rising edge of SCLK. An external interface should shift  
outgoing bits on the rising edge of SCLK, and latch incoming bits on the falling edge of SCLK. The relevant  
waveforms are illustrated in the timing diagrams (see Figure 7 to Figure 11). Timing numbers are given in  
Table 2 through Table 4.  
tXIN  
t1  
t2  
XIN  
Figure 7. XIN Clock Timing  
Table 2. XIN Timing Characteristics  
SYMBOL  
DESCRIPTION  
MIN  
1
NOM  
MAX  
2.5  
UNITS  
MHz  
ns  
fXIN  
tXIN  
t1  
XIN clock frequency  
XIN clock period  
XIN clock high  
400  
1000  
0.4 × tXIN  
0.4 × tXIN  
ns  
t2  
XIN clock low  
ns  
t3  
t4  
t5  
SCLK  
t6  
t7  
SDIO  
t8  
Figure 8. Serial Input/Output Timing  
Table 3. Serial I/O Timing Characteristics  
SYMBOL  
DESCRIPTION  
MIN  
5 × tXIN  
5 × tXIN  
40  
NOM  
MAX  
UNITS  
ns  
t3  
t4  
t5  
t6  
t7  
t8  
SCLK high  
SCLK low  
ns  
Data in valid to SCLK falling edge (setup)  
SCLK falling edge to data in not valid (hold)  
Data out valid to rising edge of SCLK (hold)  
SCLK rising edge to new data out valid (delay)  
ns  
20  
ns  
0
ns  
50  
ns  
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DAC1220  
SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009...................................................................................................................................... www.ti.com  
t9  
t14  
SCLK  
SDIO  
IN7  
IN7  
IN1  
IN1  
IN0  
INM  
IN1  
IN0  
IN7  
IN7  
Write Register Data  
SDIO  
IN0  
OUTM  
OUT1 OUT0  
Read Register Data  
Figure 9. Serial Interface Timing (CS Low)  
t15  
CS  
t10  
t10  
t9  
SCLK  
IN7  
IN1  
IN1  
IN0  
INM  
IN1  
IN0  
IN7  
SDIO  
SDIO  
Write Register Data  
IN7  
IN0  
OUTM  
OUT1 OUT0  
IN7  
Read Register Data  
Figure 10. Serial Interface Timing (Using CS)  
CS  
t11  
t12  
t10  
SCLK  
SDIO  
t13  
IN7  
IN0  
OUT MSB  
OUT0  
t9  
SDIO is an input  
SDIO is an output  
Figure 11. SDIO Input to Output Transition Timing  
Table 4. Serial Interface Timing Characteristics  
SYMBOL  
DESCRIPTION  
MIN  
NOM  
MAX  
UNITS  
ns  
Falling edge of last SCLK for command to  
rising edge of first SCLK for register data  
t9  
13 × tXIN  
11 × tXIN  
8 × tXIN  
t10  
t11  
t12  
t13  
Falling edge of CS to rising edge of SCLK  
ns  
Falling edge of last SCLK for command to SDIO as  
output  
10 × tXIN  
ns  
SDIO as output to rising edge of first SCLK  
for register data  
4 × tXIN  
ns  
ns  
Falling edge of last SCLK for register data to SDIO  
tri-state  
4 × tXIN  
6 × tXIN  
Falling edge of last SCLK for register data to  
rising edge of first SCLK of next command (CS tied  
low)  
t14  
t15  
41 × tXIN  
22 × tXIN  
ns  
ns  
Rising edge of CS to falling edge of CS (using CS)  
10  
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The chip-select pin CS is active low. When CS is  
high, activity on SCLK is ignored. There are certain  
timing limits and delays which apply to the  
manipulation of CS, as shown in Figure 10. These  
must be observed, or the DAC1220 may malfunction.  
SCLK Reset Pattern  
The DAC1220 does not have a dedicated reset pin.  
Instead, it contains a circuit which waits for a special  
pattern to appear on SCLK, and triggers the internal  
hardware reset line when it detects the special  
pattern.  
If CS is not used, it should be tied low. When CS is  
tied low, different timing limits and delays must be  
observed, as shown in Figure 9. If these are violated,  
the DAC1220 may malfunction.  
This pattern, called the SCLK reset pattern, is shown  
in Figure 12, with timing information given in Table 5.  
The pattern is very different from the usual clocking  
patterns which appear on SCLK, and is unlikely to be  
detected by accident during normal operation.  
The serial interface is byte-oriented. All data is  
transferred in groups of eight bits.  
The SCLK reset pattern can only be triggered when  
CS is low. When CS is high, the SCLK line is ignored,  
and the SCLK reset pattern is not detected.  
I/O Recovery  
The DAC1220 has a timeout on the serial interface. If  
fCLK is 2.5MHz, the timeout is approximately 100ms.  
At 2.5MHz, if a command is interrupted, and no  
activity occurs on the SCLK or CS lines for 100ms,  
the DAC1220 will cancel the command. If the  
command was a write command, no registers are  
affected.  
The timeout period scales with the frequency of fCLK  
.
Reset On  
Falling Edge  
t17  
t17  
SCLK  
t16  
t18  
t19  
Figure 12. Resetting the DAC1220  
Table 5. Reset Timing Characteristics  
SYMBOL  
DESCRIPTION  
MIN  
NOM  
MAX  
UNITS  
ns  
t16  
t17  
t18  
t19  
First high period  
Low period  
512 × tXIN  
10 × tXIN  
800 × tXIN  
ns  
Second high period  
Third high period  
1024 × tXIN  
2048 × tXIN  
1800 × tXIN  
2400 × tXIN  
ns  
ns  
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PROGRAMMING  
Commands  
Communication with the DAC1220 consists entirely of  
commands, which access the DAC1220 registers.  
Commands consist of a command byte followed by  
one, two or three data bytes. The data bytes can be  
sent to the DAC1220 or read from the DAC1220,  
depending on whether the command is a read  
command or a write command.  
Registers  
There are four registers in the DAC1220, as shown in  
the register map in Table 11. The Data Input Register  
(DIR) and the two calibration registers are 24 bits in  
length, and the Command Register (CMR), which  
contains configuration bits, is 16 bits in length.  
The format of the command byte is shown in Table 6,  
and the bits are described in Table 7. DAC1220  
commands access the register map, which is shown  
in Table 11. A DAC1220 command can read or write  
one byte, or two or three adjacent bytes, in the  
register map.  
Modes  
The DAC1220 has three operating modes: Sleep,  
Normal, and Self Calibration.  
In Sleep mode, the DAC1220 output is off (high  
impedance), and much of the internal circuitry is  
switched off. In this mode the DAC1220 draws little  
power. The oscillator continues to run, however.  
Sleep is the mode entered after reset.  
Bit and Byte Order  
The order of the bits of data bytes in a command is  
configurable. The DAC1220 can be programmed to  
output data bytes MSB first or LSB first. The  
command byte is always transmitted MSB first. See  
the description of the MSB bit in Table 6 for further  
details. The order of the data bytes themselves is  
also configurable. See the description of the BD bit in  
Table 13 for details. Note that the BD bit does not  
affect the command byte; this always comes first.  
In Normal mode, the DAC1220 is fully active, and the  
output is on.  
In Self Calibration mode, the DAC1220 runs its  
self-calibration sequence. After the sequence is  
complete, the DAC1220 switches to Normal mode.  
See the Calibration section for more information.  
Table 6. Command Byte Format  
7
6
5
4
3
2
1
0
R/W  
MB  
0
ADR  
Table 7. Command Byte Bits  
BIT(S)  
NAME  
VALUE  
DESCRIPTION  
7
R/W  
0
1
Write to register map  
Read from register map  
Number of bytes to read or write  
1 byte  
6–5  
MB  
00b  
01b  
10b  
11b  
0–15  
2 bytes  
3 bytes  
Reserved; do not use  
Start address in register map  
3–0  
ADR  
12  
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Startup Sequence  
Since the calibration functions are linear, calibration  
results can be averaged for greater precision. For  
example, it may be beneficial to perform several  
self-calibrations in succession, record the result of  
each, average them together, and store the averages  
in the OCR and FCR.  
At startup, the following procedure should generally  
be followed to properly initialize the DAC1220:  
1. If the DAC1220 is being clocked from a crystal,  
wait for the oscillator to start—at least  
25ms—before attempting to communicate with it.  
Trying to communicate with the DAC1220 before  
the crystal oscillator has reached its final  
frequency will usually result in corrupt  
communication.  
Self-Calibration Procedure  
To perform a self-calibration, place the DAC1220 into  
Self Calibration mode by setting the MD1 bit to '0'  
and the MD0 bit to '1' in the Command Register. At a  
clock frequency of 2.5MHz, self-calibration takes  
between 300ms and 500ms; the actual time is  
indeterminate and depends on the results.  
2. Optionally apply the SCLK reset pattern. This  
should also only be done once the oscillator is  
started, since the pattern is detected using  
oscillator cycles. Applying the reset pattern at  
power-up ensures that the DAC1220 is reset  
properly, and not lingering in an unknown state in  
If the CALPIN bit in the Command Register is '1', the  
output remains connected during calibration. The  
DAC voltage will change during the calibration  
process. This can be important if the DAC output is  
loaded significantly; disconnecting the output during  
calibration places a high load impedance on the  
output amplifier, which may be different from normal  
operation.  
case  
of  
POR  
failure,  
brownout,  
etc.  
After a successful reset, the DAC1220 enters  
Normal mode.  
3. Set up the Command Register as desired. This  
may include changing the mode from Sleep to  
Self Calibration or Normal.  
4. Calibrate the DAC1220. Although this step is  
optional, the DAC1220 should almost always be  
calibrated. It is permissible to run calibration  
every time, or to use values from a previous  
calibration. See the Calibration section for details.  
If the CALPIN bit in the Command Register is '0', the  
output will be disconnected during calibration. If this  
is the case, when calibration begins, the DAC1220  
briefly charges the C2 capacitor to the current output  
voltage. If the output is buffered, C2 effectively  
becomes a sample-and-hold capacitor, so that the  
final output voltage remains during calibration.  
After calibration, the DAC1220 returns to Normal  
mode. The DAC1220 is ready to accept data once it  
is in Normal mode, but calibration or the use of saved  
calibration values is highly recommended.  
When the calibration is complete, the DAC1220  
switches to Normal mode. If the output was  
disconnected, it is reconnected at that time. The end  
of the calibration procedure can be detected by  
polling the MD1 and MD0 bits. When they become 0,  
the calibration is complete.  
Calibration  
Calibration is governed by two registers. The Offset  
Calibration Register (OCR) stores  
a
value  
determining the offset calibration, and the Full-Scale  
Calibration Register (FCR) stores a value determining  
the gain calibration.  
If readback is not being performed, simply wait at  
least 500ms before sending further commands to the  
device, assuming that the clock frequency is 2.5MHz.  
The value in the OCR is scaled and additive. It has a  
linear relationship to the generated offset calibration  
voltage. The value in the FCR is scaled and  
multiplicative. It has a linear relationship to the  
generated gain calibration multiplier.  
Once calibration is complete, the OCR and FCR  
contain the results of the calibration, and the new  
constants are effective immediately.  
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Setting the Output Voltage  
The code may be given in either straight binary or  
offset two's complement format. This is controlled by  
the DF bit in the Command Register (see the register  
description in Table 13 for details). The two data  
format options and the 16- or 20-bit option give rise to  
four transfer functions, which are shown in Table 8.  
For reference, several ideal output voltages for given  
input codes are shown in Table 9.  
To set the DAC1220 output voltage, write a code to  
the Data Input Register (DIR). A write to any of the  
bytes in the DIR causes the voltage to change at the  
completion of the write command.  
The DAC1220 operates in either 16- or 20-bit mode.  
The DIR is 24 bits wide, and the code stored in it is  
left justified, with the least significant bits ignored.  
Therefore, in 16-bit mode, only the upper 16 bits of  
the DIR are significant, and in 20-bit mode, only the  
upper 20 bits of the DIR are significant.  
Note that the DIR code can also be considered a  
24-bit number. This may be convenient in software. In  
this case the transfer functions for 16- and 20-bit  
modes are the same, except that in 16-bit mode the  
code is truncated by eight bits, and in 20-bit mode the  
code is truncated by four bits.  
In 20-bit mode, all three bytes of the DIR must be  
written to in order to completely update the code. In  
16-bit mode, it is only necessary to write to the two  
upper bytes; a write to the lower byte has no effect on  
the output.  
Table 8. Transfer Functions  
DATA FORMAT  
Offset two's complement  
20-BIT MODE  
16-BIT MODE  
code)219  
code)215  
VOUT + 2VREF  
VOUT + 2VREF  
VOUT + 2VREF  
220  
216  
Straight binary  
code  
220  
code  
VOUT + 2VREF  
216  
Table 9. Example Output Voltages  
APPROXIMATE  
OUTPUT  
VOLTAGE  
(1)  
RESOLUTION  
DATA FORMAT  
Two's complement  
Straight binary  
CODE  
8000h  
0000h  
8000h  
0000h  
0000h  
8000h  
0000h  
8000h  
7FFFh  
FFFFh  
7FFFFh  
FFFFFh  
DIR CONTENT  
8000xxh  
0000xxh  
80000xh  
00000xh  
0000xxh  
8000xxh  
00000xh  
80000xh  
7FFFxxh  
FFFFxxh  
7FFFFxh  
FFFFFxh  
16-bit  
0V  
Two's complement  
Straight binary  
20-bit  
16-bit  
20-bit  
16-bit  
20-bit  
Two's complement  
Straight binary  
2.5V  
Two's complement  
Straight binary  
Two's complement  
Straight binary  
5V  
Two's complement  
Straight binary  
(1) x = Do not care  
14  
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Fast Settling Mode  
To speed up settling, the DAC1220 can change the  
cutoff frequency of its output filter. Raising the cutoff  
frequency causes the DAC1220 to settle faster, but at  
the expense of higher noise. The adaptive filtering  
mode provides a good compromise by increasing the  
filter frequency only while the DAC is changing its  
output by more than approximately 40mV. When the  
output has settled, the filter frequency is reduced  
again.  
REGISTERS  
The register map is shown in Table 11.  
Table 11. Register Memory Map  
ADDRESS  
CONTENT  
DIR byte 2 (MSB)  
0
1
DIR byte 1  
2
DIR byte 0 (LSB)  
Reserved  
Adaptive filtering is controlled by the ADPT and DISF  
bits in the Command Register. The action of these  
bits together is described in Table 10.  
3
4
CMR byte 1 (MSB)  
CMR byte 0 (LSB)  
Reserved  
5
6
Table 10. Fast Settling Modes  
7
Reserved  
ADPT  
DISF  
8
OCR byte 2 (MSB)  
OCR byte 1  
(CMR bit 15) (CMR bit 4)  
FAST SETTLING MODE  
9
0
0
Fast settling only during > 40mV  
step  
10  
11  
12  
13  
14  
15  
OCR byte 0 (LSB)  
Reserved  
0
1
1
0
Disabled  
Fast settling always on (filter cutoff  
increased)  
FCR byte 2 (MSB)  
FCR byte 1  
1
1
Disabled  
FCR byte 0 (LSB)  
Reserved  
space  
Command Register (CMR)  
The command register contains the configuration bits of the DAC1220. It is shown in Table 12. The bits in the  
command register are shown in Table 13.  
Writes to the CMR take effect at the negative edge of SCLK during the last bit of the last byte of the write  
command.  
blank  
Table 12. Command Register  
15  
14  
13  
12  
Reserved  
R-0  
11  
Reserved  
R-1  
10  
Reserved  
R-0  
9
8
ADPT  
R/W-0  
CALPIN  
R/W-0  
Reserved  
R-1(1)  
CRST  
R/W-0  
Reserved  
R-0  
(1) In early versions of the DAC1220, this bit was rw-0. See the Calibration section for details.  
7
6
5
4
3
2
1
0
RES  
R/W-0  
CLR  
R/W-0  
DF  
DISF  
R/W-0  
BD  
MSB  
R/W-0  
MD  
R/W-0  
R/W-0  
R/W-10b  
LEGEND: R = Read, W = Write  
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Table 13. Command Register Bits  
BIT(S)  
NAME  
VALUE  
DESCRIPTION  
Controls adaptive filtering. if DISF is set, this bit has no effect.  
Adaptive filtering enabled (default).  
15  
ADPT  
0
1
0
1
Adaptive filtering disabled.  
14  
13  
CALPIN  
Output is disconnected (high impedance) during calibration (default).  
Output is connected during calibration.  
Reserved  
Write '1' to this bit. On early versions of the device, this bit is writable and  
defaults to zero, but still should be set to '1'. On current devices this bit is read-  
only and always reads '1'. See the Calibration section for details.  
12  
11  
10  
9
Reserved  
Reserved  
Reserved  
CRST  
Read-only. Always '0'.  
Read-only. Always '0'.  
Read-only. Always '0'.  
In Normal mode, writing '1' to this bit resets the calibration registers, setting  
OCR to 000000h and FCR to 800000h. In Normal mode, this bit always reads  
'0'.  
In Sleep mode, this bit is read/write, and has no effect.  
Writing '1' to this bit and switching to Normal mode at the same time will reset  
the calibration registers.  
0
1
Do not clear calibration registers.  
Clear calibration registers.  
8
7
Reserved  
RES  
Read-only. Always '0'.  
Selects resolution.  
0
1
16-bit resolution (default).  
20-bit resolution.  
6
CLR  
In Normal mode, writing '1' to this bit writes 0 to the data register.  
In Sleep mode, this bit is read/write, and has no effect.  
Writing '1' to this bit and switching to Normal mode at the same time will reset  
the data register.  
The actual voltage that the DAC1220 will output on setting this bit depends on  
the data format selected by DF. If DF is 1, zero gives 0V; if DF is 0, zero gives  
VREF (mid-scale).  
0
1
Do not clear calibration registers.  
Clear calibration registers.  
5
4
3
DF  
DISF  
BD  
Selects binary number format of the data register.  
Offset two's complement (default).  
0
1
Straight binary.  
Can be used to inhibit fast settling and/or adaptive filtering. See text for details.  
Fast settling and/or adaptive filtering enabled (default).  
Fast settling disabled; filter always at default cutoff.  
0
1
Selects address increment or decrement when reading or writing multiple bytes,  
except when writing to the command register. The command register is always  
written to in increment mode (most significant byte first). Reads from the  
command register are according to this bit.  
0
1
Address is incremented after each byte (default).  
Address is decremented after each byte.  
16  
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Table 13. Command Register Bits (continued)  
BIT(S)  
NAME  
VALUE  
DESCRIPTION  
2
MSB  
Selects the order in which bits are shifted in and out of the DAC1220, except  
when writing to the command register. The command register is always written  
to MSB first. Reads from the command register are according to this bit.  
0
1
Data is shifted MSB first (default).  
Data is shifted LSB first.  
Operating mode.  
1-0  
MD  
00b  
01b  
Normal mode (default).  
Self calibration mode. (No other bits should be changed in the Command  
Register when setting this mode.)  
10b  
11b  
Sleep mode.  
Reserved.  
Data Input Register (DIR)  
The Data Input Register determines the output  
voltage in Normal mode.  
After reset, the OCR contains zero. See the  
Calibration section for further details about the OCR.  
In Sleep mode, writing to this register has no effect  
on the output, but the value is stored. The value in  
the DIR becomes effective immediately upon entering  
Normal mode.  
Full-Scale Calibration Register (FCR)  
The Full-Scale Calibration Register stores the gain  
calibration constant. The content of the DIR is  
adjusted multiplicatively by this value before  
conversion by the DAC.  
After reset, the DIR contains zero.  
See the section, Setting the Output Voltage for further  
details about the Data Input Register.  
In Sleep mode, writing to this register has no effect  
on the output, but the value is stored. The value in  
the FCR becomes effective immediately upon  
entering Normal mode.  
Offset Calibration Register (OCR)  
The Offset Calibration Register contains a 24-bit  
two's complement value. This value is added to the  
value in the DIR before conversion by the DAC.  
After reset, the FCR contains 800000h.  
See the Calibration section for further details about  
the FCR.  
In Sleep mode, writing to this register has no effect  
on the output, but the value is stored. The value in  
the OCR becomes effective immediately upon  
entering Normal mode.  
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APPLICATION INFORMATION  
Note that the delays are slightly different if chip-select  
(CS) is not being used.  
Layout Recommendations  
The DAC1220 is a high-precision analog component  
Timing delays from the beginning of an SPI byte  
incorporating digital elements. Achieving good  
transmission  
are  
a
common  
problem  
in  
precision is not difficult, but achieving excellent  
precision may require several attempts.  
microcontroller firmware that uses an SPI peripheral.  
Be sure that any delay routine begins once a byte  
has completed transmission, or add the byte  
transmission time to the delay time.  
It is critical to supply a guard ring, or fill, around the  
C1 and C2 pins. The guard ring should be connected  
to the voltage reference. These nodes are very  
sensitive, and are good places for noise to couple  
through to the output. A ground fill on the opposite  
side of the board, or a ground plane, is also a good  
idea.  
Some programmers may find that bit-banging, or  
direct manipulation of microcontroller I/O pins, is the  
easiest way to communicate with the DAC1220,  
because of the delays and direction changes  
required.  
The capacitors themselves should be placed as near  
the pins as possible. In particular, the traces leading  
from C1 and C2 should be kept very short. The traces  
leading to VOUT and VREF can be longer.  
Write-Only Interfacing  
In some situations, such as isolated interfacing, it is  
inconvenient to use the DAC1220 bidirectionally,  
since the SDIO pin changes direction for readback.  
The DAC1220 can be used write-only. The following  
considerations apply:  
It is also very important to route digital traces away  
from analog traces, so that their associated return  
currents will not couple into the analog side.  
When used write-only, it is not possible to verify  
that the DAC1220 is operating using its serial  
interface alone. The operation of the DAC is  
open-loop.  
It may be helpful to wait at least 150ms-200ms  
after startup. This ensures that, in case the reset  
was a result of firmware problems and not  
power-up, any previous communication with the  
DAC has been cancelled by the I/O recovery  
timeout.  
When applying the SCLK reset pattern, which can  
be done in place of the above steps, allow time for  
the oscillator to start before applying the pattern.  
The pattern is detected based on oscillator cycles,  
so it will not be detected if the oscillator is not yet  
running.  
If a crystal is used, do not route the traces connecting  
the crystal to the device through vias, if possible,  
because this will increase the trace inductance and  
may affect startup and reliability. Keep the traces  
short, and place the crystal close to the device. Keep  
in mind that extra ground planes and trace lengths  
increase parasitic capacitance, and this should be  
deducted from the load capacitor values.  
Software Considerations  
A
key to communicating successfully with the  
DAC1220 is observing the delays in the interface  
timing diagrams. A violation of these delays, at best,  
results in lack of correct output; at worse, violating the  
delays can corrupt communications entirely.  
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Isolation  
Full-Scale Range (FSR)—This is the magnitude of  
the typical analog output voltage range, which is 2 ×  
VREF. For example, when the converter is configured  
with a 2.5V reference, the Full-Scale range is 5.0V.  
The DAC1220 serial interface allows for connection  
using as few as two wires. This is an advantage  
when galvanic isolation is required. An example  
isolated connection is shown in Figure 13. Here,  
chip-select is unused and therefore grounded, and  
the DAC1220 is being operated unidirectionally.  
Gain Error—This error represents the difference in  
the slope between the actual and ideal transfer  
functions.  
Linearity Error—The deviation of the actual transfer  
function from an ideal straight line between the data  
end points.  
DAC1220 Revisions  
As of this writing, there have been two released  
revisions of the DAC1220. The only difference  
between the two versions is bit 13 of the Command  
Register. In the first revision, this bit was writable,  
and defaulted to '0'. In the current revision, which was  
released in 1999, this bit is fixed at '1', and is not  
writable.  
Least Significant Bit (LSB) Weight—This is the  
ideal change in voltage that the analog output  
changes with a change in the digital input code of  
1LSB.  
Monotonicity—Monotonicity assures that the analog  
output will increase or stay the same for increasing  
digital input codes.  
For first revision chips, always write a '1' to this bit.  
Although the bit is not critical, performance is not  
optimal unless this bit is set.  
Offset Error—The difference between the expected  
and actual output, when the output is zero. The value  
This does no harm in current revision chips, and  
ensures that first revision chips perform optimally.  
is calculated from measurements made when VOUT  
20mV.  
=
Settling Time—The time it takes the output to settle  
to a new value after the digital code has been  
changed.  
Definition of Terms  
Differential Nonlinearity Error—The difference  
between an actual step width and the ideal value of  
1LSB. If the step width is exactly 1LSB, the  
differential nonlinearity error is zero. A differential  
nonlinearity specification of less than 1LSB ensures  
monotonicity.  
fXIN —The frequency of the crystal oscillator or  
CMOS-compatible input signal at the XIN input of the  
DAC1220.  
Drift—The change in a parameter over temperature.  
Isolated  
Power  
DVDD  
Opto  
Coupler  
8051  
P1.1  
P1.0  
DAC1220  
C1  
12pF  
1
2
3
4
5
6
7
8
DVDD  
XOUT  
XIN  
SCLK 16  
SDIO 15  
CS 14  
Opto  
Coupler  
XTAL  
C2  
12pF  
DGND  
AVDD  
DNC  
DNC  
DNC  
AGND 13  
VREF 12  
VOUT 11  
C2 10  
AVDD  
VREF  
= Isolated  
= DGND  
= AGND  
VOUT  
C2  
C1  
C1  
9
Figure 13. Isolation for Two-Wire Interface  
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DAC1220  
SBAS082G FEBRUARY 1998REVISED SEPTEMBER 2009...................................................................................................................................... www.ti.com  
REVISION HISTORY  
Changes from Revision F (March, 2008) to Revision G ................................................................................................. Page  
Revised Table 4, Serial Interface Timing Characteristics; changed INSR to command for all occurrences ...................... 10  
Changes from Revision E (December 2007) to Revision F ............................................................................................ Page  
Updated device graphic to TI logo ........................................................................................................................................ 1  
Changed description of the 01b row in the 1-0 bits section of Table 13 ............................................................................ 16  
20  
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Copyright © 1998–2009, Texas Instruments Incorporated  
Product Folder Link(s): DAC1220  
PACKAGE OPTION ADDENDUM  
www.ti.com  
16-Aug-2012  
PACKAGING INFORMATION  
Status (1)  
Eco Plan (2)  
MSL Peak Temp (3)  
Samples  
Orderable Device  
Package Type Package  
Drawing  
Pins  
Package Qty  
Lead/  
Ball Finish  
(Requires Login)  
DAC1220E  
DAC1220E/2K5  
DAC1220E/2K5G4  
DAC1220EG4  
ACTIVE  
ACTIVE  
ACTIVE  
ACTIVE  
SSOP  
SSOP  
SSOP  
SSOP  
DBQ  
DBQ  
DBQ  
DBQ  
16  
16  
16  
16  
75  
2500  
2500  
75  
Green (RoHS  
& no Sb/Br)  
CU NIPDAU Level-2-260C-1 YEAR  
Green (RoHS  
& no Sb/Br)  
CU NIPDAU Level-2-260C-1 YEAR  
CU NIPDAU Level-2-260C-1 YEAR  
CU NIPDAU Level-2-260C-1 YEAR  
Green (RoHS  
& no Sb/Br)  
Green (RoHS  
& no Sb/Br)  
(1) The marketing status values are defined as follows:  
ACTIVE: Product device recommended for new designs.  
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.  
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.  
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.  
OBSOLETE: TI has discontinued the production of the device.  
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability  
information and additional product content details.  
TBD: The Pb-Free/Green conversion plan has not been defined.  
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that  
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.  
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between  
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.  
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight  
in homogeneous material)  
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.  
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information  
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and  
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.  
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.  
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.  
Addendum-Page 1  
PACKAGE MATERIALS INFORMATION  
www.ti.com  
16-Aug-2012  
TAPE AND REEL INFORMATION  
*All dimensions are nominal  
Device  
Package Package Pins  
Type Drawing  
SPQ  
Reel  
Reel  
A0  
B0  
K0  
P1  
W
Pin1  
Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant  
(mm) W1 (mm)  
DAC1220E/2K5  
SSOP  
DBQ  
16  
2500  
330.0  
12.4  
6.4  
5.2  
2.1  
8.0  
12.0  
Q1  
Pack Materials-Page 1  
PACKAGE MATERIALS INFORMATION  
www.ti.com  
16-Aug-2012  
*All dimensions are nominal  
Device  
Package Type Package Drawing Pins  
SSOP DBQ 16  
SPQ  
Length (mm) Width (mm) Height (mm)  
367.0 367.0 35.0  
DAC1220E/2K5  
2500  
Pack Materials-Page 2  
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