LTC2704
Quad 12-, 14- and 16-Bit
Voltage Output SoftSpan
DACs with Readback
FEATURES
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DESCRIPTION
The LTC
®
2704-16/LTC2704-14/LTC2704-12 are serial
input, 12-, 14- or 16-bit, voltage output SoftSpan™ DACs
that operate from 3V to 5V logic and ±5V to ±15V analog
supplies. SoftSpan offers six output spans—two unipolar
and four bipolar—fully programmable through the 3-wire
SPI serial interface. INL is accurate to 1LSB (2LSB for the
LTC2704-16). DNL is accurate to 1LSB for all versions.
Readback commands allow verification of any on-chip
register in just one 24- or 32- bit instruction cycle. All other
commands produce a “rolling readback” response from
the LTC2704, dramatically reducing the needed number
of instruction cycles.
A Sleep command allows any combination of DACs to be
powered down. There is also a reset flag and an offset
adjustment pin for each channel.
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. SoftSpan is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
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Six Programmable Output Ranges:
Unipolar: 0V to 5V, 0V to 10V
Bipolar: ±5V, ±10V, ±2.5V, –2.5V to 7.5V
Serial Readback of All On-Chip Registers
1LSB INL and DNL Over the Industrial
Temperature Range (LTC2704-14/LTC2704-12)
Force/Sense Outputs Enable Remote Sensing
Glitch Impulse: < 2nV-sec
Outputs Drive ±5mA
Pin Compatible 12-, 14- and 16-Bit Parts
Power-On and Clear to Zero Volts
44-Lead SSOP Package
APPLICATIONS
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Process Control and Industrial Automation
Direct Digital Waveform Generation
Software Controlled Gain Adjustment
Automated Test Equipment
BLOCK DIAGRAM
AGND
32
VOSB 40
C1B 39
RFBB 37
DAC B
OUTB 38
AGNDB 41
VOSA 4
C1A 5
RFBA 7
DAC A
OUTA 6
AGNDA 3
33
34
10
13
11
SDI
14
CLR
9
35
12
DAC D
17 OUTD
20 AGNDD
GND V
DD
CS/LD
SCK
LDAC RFLAG
SRO
2704 BD
V
+1
42
V
–
REFM1 REFG1 REF1 REF2 REFG2 REFM2 V
+2
1,8,15,22,31,36
24
21
44
2
23
43
25
27 VOSC
28 C1C
DAC C
–1
–1
26 AGNDC
19 VOSD
18 C1D
16 RFBD
30 RFBC
29 OUTC
LTC2704-16
Integral Nonlinearity (INL)
1.0
V+/V
–
= ±15V
0.8 V
REF
= 5V
±10V RANGE
0.6
ALL 4 DACS
0.4 SUPERIMPOSED
INL (LSB)
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
16384
32768
CODE
49152
65535
2704 TA01b
2704fd
1
LTC2704
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
V
–
REFG1
AGNDA
VOSA
C1A
OUTA
RFBA
V
–
LDAC
1
2
3
4
5
6
7
8
9
44 REFM1
43 REF1
42 V
+1
41 AGNDB
40 VOSB
39 C1B
38 OUTB
37 RFBB
36 V
–
35
RFLAG
34 V
DD
33 GND
32 AGND
31 V
–
30 RFBC
29 OUTC
28 C1C
27 VOSC
26 AGNDC
25 V
+2
24 REF2
23 REFM2
Total Supply Voltage V
+1
, V
+2
to V
–
........... –0.3V to 36V
V
+1
, V
+2
, REF1, REF2, REFM1, REFM2,
OUTx, RFBx, V
OSx
to GND, AGND,
AGNDx, C1x, REFG1, REFG2 .....................................18V
GND, AGND, AGNDx, C1x, REFG1, REFG2 to V
+1
,
V
+2
, V
–
, REF1, REF2, REFM1, REFM2, OUTx,
RFBx, V
OSx
...............................................................18V
OUTA, RFBA, V
OSA
, OUTB, RFBB, VOSB, REF1,
REFM1 to GND, AGND ............... V
–
– 0.3V to V
+1
+ 0.3V
OUTC, RFBC, V
OSC
, OUTD, RFBD, V
OSD
, REF2, REFM2
to GND, AGND............................ V
–
– 0.3V to V
+2
+ 0.3V
V
DD
, Digital Inputs/Outputs to GND ............. –0.3V to 7V
Digital Inputs/Outputs to V
DD
..................................0.3V
GND, AGNDx, REFG1, REFG2 to AGND ..................±0.3V
C1x to AGNDx ........................................................±0.3V
V
–
to Any Pin ...........................................................0.3V
Maximum Junction Temperature.......................... 150°C
Operating Temperature Range
LTC2704C ................................................ 0°C to 70°C
LTC2704I..............................................– 40°C to 85°C
Storage Temperature Range...................– 65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
CS/LD
10
SDI 11
SRO 12
SCK 13
CLR
14
V
–
15
RFBD 16
OUTD 17
C1D 18
VOSD 19
AGNDD 20
REFG2 21
V
–
22
GW PACKAGE
44-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 80°C/W
ORDER INFORMATION
LEAD FREE FINISH
LTC2704CGW-16#PBF
LTC2704IGW-16#PBF
LTC2704CGW-14#PBF
LTC2704IGW-14#PBF
LTC2704CGW-12#PBF
LTC2704IGW-12#PBF
TAPE AND REEL
LTC2704CGW-16#TRPBF
LTC2704IGW-16#TRPBF
LTC2704CGW-14#TRPBF
LTC2704IGW-14#TRPBF
LTC2704CGW-12#TRPBF
LTC2704IGW-12#TRPBF
PART MARKING
LTC2704CGW-16
LTC2704IGW-16
LTC2704CGW-14
LTC2704IGW-14
LTC2704CGW-12
LTC2704IGW-12
PACKAGE DESCRIPTION
44-Lead Plastic SSOP
44-Lead Plastic SSOP
44-Lead Plastic SSOP
44-Lead Plastic SSOP
44-Lead Plastic SSOP
44-Lead Plastic SSOP
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
2704fd
2
LTC2704
ELECTRICAL CHARACTERISTICS
SYMBOL
Accuracy
Resolution
Monotonicity
INL
DNL
GE
Integral Nonlinearity
Differential Nonlinearity
Gain Error
Gain Temperature
Coefficient
V
OS
Unipolar Zero-Scale
Error
V
REF
= 5V
V
REF
= 5V
V
REF
= 5V
ΔGain/ΔTemperature
Span = 0V to 5V, T
A
= 25°C
Span = 0V to 10V, T
A
= 25°C
Span = 0V to 5V
Span = 0V to 10V
0V to 5V Range
0V to 10V Range
All Bipolar Ranges
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l
l
l
l
l
l
The
l
denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C, V
+1
= V
+2
= 15V, V
–
= –15V, V
DD
= 5V, REF1 = REF2 = 5V, AGND = AGNDx =
REFG1 = REFG2 = GND = 0V.
PARAMETER
CONDITIONS
LTC2704-12
MIN TYP MAX
12
12
±1
±1
±0.5
±2
±80
±100
±140
±150
±2
±2
±0.25
±0.003
±0.006
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l
LTC2704-14
MIN TYP MAX
14
14
±1
±1
±1
±2
±5
LTC2704-16
MIN TYP MAX
16
16
±2
±1
±4
±2
±20
UNITS
Bits
Bits
LSB
LSB
LSB
ppm/°C
±2
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l
l
l
±200
±300
±400
±600
± 80
±100
±140
±150
±2
±2
±200
±300
±400
±600
±80
±100
±140
±150
±2
±2
±200
±300
±400
±600
μV
μV
μV
μV
μV/°C
μV/°C
V
OS
Temperature
Coefficient
BZE
PSRR
Bipolar Zero
Error
Power Supply
Rejection Ratio
±1
±2
±0.5
±0.013
±0.025
±2
±2.5
±2
±0.05
±0.1
±8
±12
LSB
LSB
LSB/V
LSB/V
LSB/V
LSB/V
V
DD
= 5V ±10% (Note 3)
V
DD
= 3V ±10% (Note 3)
0V to 10V Range, Code = 0
V
+
/V
–
= ±15V ±10% (Note 2)
V
+
/V
–
= ±5V ±10%, V
REF
= 2V (Note 2)
0V to 5V Range, 5V Step, to ±1LSB
0V to 10V or ±5V Range,
10V Step, to ±1LSB
±10V Range, 20V Step, to ±1LSB
V
+
/V
–
= ±15V, V
REF
= ±7.25V,
0V to 10V Range, I
LOAD
= ±3mA (Note 2)
±0.001 ±0.06
±0.002 ±0.05
±0.005 ±0.25
±0.01 ±0.13
±0.02 ±0.1
±0.04 ±0.5
Analog Outputs (Note 4)
Settling Time
3
5
8
l
–14.3
3.5
5.5
9
14.3 –14.3
4.5
±5
±4
±3
±2.7
±0.005
–4.5
14.3 –14.3
4.5
±5
±4
±3
±2.7
±0.01
–4.5
4
6
10
14.3
4.5
±5
±4
±3
±2.7
±0.04
μs
μs
μs
V
V
mA
mA
mA
mA
LSB/mA
Output Swing
l
–4.5
V
+
/V
–
= ±5V, V
REF
= ±2.25V,
0V to 10V Range, I
LOAD
= ±2.5mA (Note 2)
Load Current
V
+
/V
–
= ±10.8V to ±16.5V, V
REF
= ±5V,
0V to 10V Range, V
OUT
= ±10V (Note 2)
V
+
/V
–
= ±4.5V to ±16.5V, V
REF
= ±2V,
0V to 10V Range, V
OUT
= ±4V (Note 2)
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l
Load Regulation
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V
+
/V
–
= ±15V, V
REF
= 5V,
0V to 10V Range, Code = 0, ±5mA Load
(Note 2)
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V
+
/V
–
= ±5V, V
REF
= 2V,
0V to 10V Range, Code = 0, ±3mA Load
(Note 2)
±0.01
±0.013
±0.05
LSB/mA
Output
Impedance
I
SC
Short-Circuit
Current
V
REF
= 5V, 0V to 10V Range,
Code = 0, ±5mA Load
V
+
/V
–
= ±16.5V, V
REF
= 5V, ±10V Range
Code = 0, V
OUT
Shorted to V
+
(Note 2)
Code = Full Scale, V
OUT
Shorted to V
–
V
+
/V
–
= ±5.5V, V
REF
= 2V, ±10V Range
Code = 0, V
OUT
Shorted to V
+
(Note 2)
Code = Full Scale, V
OUT
Shorted to V
–
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0.015
0.006
0.006
Ω
l
l
–36
l
38
–36
38
–36
38
–36
38
–36
38
mA
mA
mA
mA
2704fd
38
l
–36
3
LTC2704
The
l
denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C, V
+1
= V
+2
= 15V, V
–
= –15V, V
DD
= 5V, REF1 = REF2 = 5V, AGND = AGNDx =
REFG1 = REFG2 = GND = 0V.
SYMBOL
SR
PARAMETER
Slew Rate
Capacitive Load
Driving
CONDITIONS
R
L
= 2k, V
+
/V
–
= ±15V (Note 2)
R
L
= 2k, V
+
/V
–
= ±5V (Note 2)
Within Maximum Load Current
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ELECTRICAL CHARACTERISTICS
LTC2704-12
MIN TYP MAX
2.2
2.0
3
2.8
1000
LTC2704-14
MIN TYP MAX
2.2
2.0
3
2.8
1000
LTC2704-16
MIN TYP MAX
2.2
2.0
3
2.8
1000
UNITS
V/μs
V/μs
pF
The
l
denotes specifications which apply over the full operating temperature range, otherwise specifications are T
A
= 25°C,
V
+1
= V
+2
= 15V, V
–
= –15V, V
DD
= 5V, REF1 = REF2 = 5V, AGND = AGNDx = REFG1 = REFG2 = GND = 0V.
SYMBOL
Reference Inputs
REF1, REF2 Input Voltage
Resistances
R
REF1,
R
REF2
R
FBx
R
VOSX
Reference Input Resistance
Output Feedback Resistance
Offset Adjust Input Resistance
Glitch Impulse
Crosstalk
0V to 5V Range, Midscale Transition
10V Step on V
OUTA
DAC B: 0V to 5V Range, Full Scale
DAC B: 0V to 10V Range, Full Scale
±10V Range, Midscale
0V to 10V Range, V
REF
= ±5V, 10kHz Sine Wave
Span = 0V to 5V, Full Scale
Span = 0V to 10V, Full Scale
10kHz
Span = 0V to 5V, Midscale
Span = 0V to 10V, Midscale
0.1Hz to 10Hz
Span = 0V to 5V, Midscale
Span = 0V to 10V, Midscale
Digital Inputs = 0V or V
DD
V
+
/V
–
= ±15V ±10%; V
REF
= 5V V
OUT
= 0V (Note 2)
,
,
V
+
/V
–
= ±5V, ±10%; V
REF
= 2V, V
OUT
= 0V (Note 2)
Sleep Mode—All DACs (Note 4)
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l
l
PARAMETER
CONDITIONS
V
+
/V
–
= ±15V, 0V to 5V Span (Note 2)
l
MIN
–14.5
5
7
700
TYP
MAX
14.5
UNITS
V
kΩ
kΩ
kΩ
nV-s
nV-s
nV-s
nV-s
mV
P-P
kHz
kHz
nV/√Hz
nV/√Hz
μV
RMS
μV
RMS
7
10
1000
2
2
3
0.2
0.35
300
250
30
50
0.8
1.2
0.5
17.5
17.0
2
20
18
1
5.5
16.5
–4.5
AC Performance (Note 4)
Digital Feedthrough
Multiplying Feedthrough Error
Multiplying Bandwidth
Output Noise Voltage Density
Output Noise Voltage
Power Supply
I
DD
I
S
Supply Current, V
DD
Supply Current, V
+
/V
–
μA
mA
mA
mA
V
V
V
V
V
0.6
0.8
V
CC
– 0.4
0.4
0.001
±1
V
V
V
V
μA
2704fd
V
DD
V
+1
/V
+2
V
–
V
IH
V
IL
V
OH
V
OL
I
IN
Logic Supply Voltage
Positive Analog Supply Voltage
Negative Analog Supply Voltage
Digital Input High Voltage
Digital Input Low Voltage
Digital Output High Voltage
Digital Output Low Voltage
Digital Input Current
V
DD
= 2.7V to 5.5V
V
DD
= 2.7V to 3.3V
V
DD
= 2.7V to 5.5V
V
DD
= 4.5V to 5.5V
I
OH
= 200μA
I
OL
= 200μA
2.7
4.5
–16.5
2.4
2.0
Digital Inputs/Outputs
4
LTC2704
The
l
denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C, V
+1
= V
+2
= 15V, V
–
= –15V, V
DD
= 5V, REF1 = REF2 = 5V, AGND = AGNDx =
REFG1 = REFG2 = GND = 0V.
SYMBOL
C
IN
PARAMETER
Digital Input Capacitance
CONDITIONS
V
IN
= 0V (Note 3)
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ELECTRICAL CHARACTERISTICS
MIN
TYP
MAX
5
UNITS
pF
TIMING CHARACTERISTICS
range, otherwise specifications are at T
A
= 25°C.
SYMBOL
V
DD
= 4.5V to 5.5V
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
t
10
t
11
t
12
t
13
V
DD
= 2.7V to 3.3V
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
t
10
t
11
t
12
t
13
SDI Valid to SCK Setup
SDI Valid to SCK Hold
SCK High Time
SCK Low Time
CS/LD
Pulse Width
LSB SCK High to
CS/LD
High
CS/LD
Low to SCK Positive Edge
CS/LD
High to SCK Positive Edge
SRO Propagation Delay
CLR
Pulse Width
LDAC
Pulse Width
CLR
Low to
RFLAG
Low
CS/LD
High to
RFLAG
High
SCK Frequency
SDI Valid to SCK Setup
SDI Valid to SCK Hold
SCK High Time
SCK Low Time
CS/LD
Pulse Width
LSB SCK High to
CS/LD
High
CS/LD
Low to SCK Positive Edge
CS/LD
High to SCK Positive Edge
SRO Propagation Delay
CLR
Pulse Width
LDAC
Pulse Width
CLR
Low to
RFLAG
Low
CS/LD
High to
RFLAG
High
SCK Frequency
PARAMETER
The
l
denotes specifications which apply over the full operating temperature
CONDITIONS
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l
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MIN
7
7
11
11
9
0
12
12
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
C
LOAD
= 10pF
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l
l
18
50
15
50
40
40
9
9
15
15
12
0
12
12
26
90
20
70
60
25
ns
ns
ns
ns
ns
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MHz
C
LOAD
= 10pF (Note 3)
C
LOAD
= 10pF (Note 3)
50% Duty Cycle (Note 5)
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l
C
LOAD
= 10pF
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C
LOAD
= 10pF
C
LOAD
= 10pF
50% Duty Cycle (Note 5)
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l
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Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
The notation V
+
is used to denote both V
+1
and V
+2
when the same
voltage is applied to both pins.
Note 3:
Guaranteed by design, not subject to test.
Note 4:
Measured in unipolar 0V to 5V mode.
Note 5:
When using SRO, maximum SCK frequency f
MAX
is limited by SRO
propagation delay as follows:
f
MAX
=
1
2
(
t
9
+
t
S
)
, where t
s
is the setup time of the receiving device.
2704fd
5
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