DAC7728 Datasheet, PDF (7/54 Pages) Texas Instruments – Octal, 12-Bit, Low-Power, High-Voltage Output, Parallel Input DIGITAL-TO-ANALOG CONVERTER

DAC7728
www.ti.com
SBAS461A – JUNE 2009 – REVISED NOVEMBER 2009
ELECTRICAL CHARACTERISTICS: Single-Supply
All specifications at T_A = T_MIN to T_MAX, AV_DD = +32V, AV_SS = 0V, DV_DD = +5V, REF-A and REF-B = +5V, gain = 6, AGND-x =
DGND = 0V, and OFFSET-A = OFFSET-B = AGND, unless otherwise noted.
PARAMETER
CONDITIONS
STATIC PERFORMANCE
Resolution
Linearity error
Measured by line passing through codes 010h and FFFh
Differential linearity error
Measured by line passing through codes 010h and FFFh
Unipolar zero error
Unipolar zero error TC
T_A = +25°C, gain = 4 or 6, code = 010h
Gain = 4 or 6, code = 010h
Gain error
Gain error TC
T_A = +25°C, gain = 4 or 6
Gain = 4 or 6
Full-scale error
Full-scale error TC
T_A = +25°C, gain = 4 or 6, code = FFFh
Gain = 4 or 6, code = FFFh
DC crosstalk⁽¹⁾
Measured channel at code = 800h, full-scale change on any
other channel
ANALOG OUTPUT (V_OUT-0 to V_OUT-7)⁽²⁾
Voltage output⁽³⁾
V_REF = +5V
V_REF = +1.5V
Output impedance
Code = 800h
Short-circuit current⁽⁴⁾
Load current
See Figure 89 and Figure 90
Output drift vs time
Capacitive load stability
T_A = +25°C, Device operating for 500 hours, full-scale output
T_A = +25°C, Device operating for 1000 hours, full-scale output
To 0.03% of FSR, C_L = 200pF, R_L= 10kΩ, code from 010h to
FFFh and FFFh to 010h
Settling time
To 1 LSB, C_L = 200pF, R_L = 10kΩ, code from 010h to FFFh
and FFFh to 010h
To 1 LSB, C_L = 200pF, R_L = 10kΩ, code from 7C0h to 840h
and 840h to 7C0h
Slew rate⁽⁵⁾
Power-on delay⁽⁶⁾
Power-down recovery time
Digital-to-analog glitch⁽⁷⁾
From IOV_DD ≥ +1.8V and DV_DD ≥ +2.7V to CS low
Code from 7FFh to 800h and 800h to 7FFh
Glitch impulse peak amplitude Code from 7FFh to 800h and 800h to 7FFh
Channel-to-channel isolation⁽⁸⁾
DAC-to-DAC crosstalk⁽⁹⁾
Digital crosstalk⁽¹⁰⁾
V_REF = 4V_PP, f = 1kHz
DACs in the same group
DACs among different groups
DAC7728
MIN
TYP
12
±0.5
±1
±0.5
0.05
0
0
±10
±3
3.4
4.3
10
15
6
6
200
50
4
5
88
10
1
1
MAX
UNIT
Bits
±1
LSB
±1
LSB
±1
LSB
±3 ppm FSR/°C
±1
LSB
±3 ppm FSR/°C
±1
LSB
±3 ppm FSR/°C
LSB
+30
V
+9
V
0.5
Ω
mA
mA
ppm of FSR
ppm of FSR
500
pF
μs
μs
μs
V/μs
μs
μs
nV-s
mV
dB
nV-s
nV-s
nV-s
(1) The DAC outputs are buffered by op amps that share common AV_DD and AV_SS power supplies. DC crosstalk indicates how much dc
change in one or more channel outputs may occur when the dc load current changes in one channel (because of an update). With
high-impedance loads, the effect is virtually immeasurable. Multiple AV_DD and AV_SS terminals are provided to minimize dc crosstalk.
(2) Specified by design.
(3) The analog output range of V_OUT-0 to V_OUT-7 is equal to (6 × V_REF) for gain = 6. The maximum value of the analog output must not be
greater than (AV_DD – 0.5V). All specifications are for a +32V power supply and a 0V to +30V output, unless otherwise noted.
(4) When the output current is greater than the specification, the current is clamped at the specified maximum value.
(5) Slew rate is measured from 10% to 90% of the transition when the output changes from 0 to full-scale.
(6) Power-on delay is defined as the time from when the supply voltages reach the specified conditions to when CS goes low, for valid
digital communication.
(7) Digital-to-analog glitch is defined as the amount of energy injected into the analog output at the major code transition. It is specified as
the area of the glitch in nV-s. It is measured by toggling the DAC register data between 7FFh and 800h in straight binary format.
(8) Channel-to-channel isolation refers to the ratio of the signal amplitude at the output of one DAC channel to the amplitude of the
sinusoidal signal on the reference input of another DAC channel. It is expressed in dB and measured at midscale.
(9) DAC-to-DAC crosstalk is the glitch impulse that appears at the output of one DAC as a result of both the full-scale digital code and
subsequent analog output change at another DAC. It is measured with LDAC tied low and expressed in nV-s.
(10) Digital crosstalk is the glitch impulse transferred to the output of one converter as a result of a full-scale code change in the DAC input
register of another converter. It is measured when the DAC output is not updated, and is expressed in nV-s.
Copyright © 2009, Texas Instruments Incorporated
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