LTC2704
Quad 12-, 14- and 16-Bit
Voltage Output SoftSpan
DACs with Readback
FEATURES
■
DESCRIPTIO
■
■
■
■
■
■
■
■
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
The LTC
®
2704-16/LTC2704-14/LTC2704-12 are serial in-
put, 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.
, LT, LTC and LTM 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.
APPLICATIO S
■
■
■
■
Process Control and Industrial Automation
Direct Digital Waveform Generation
Software Controlled Gain Adjustment
Automated Test Equipment
SI PLIFIED BLOCK DIAGRA
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
–1
–1
V
+ 1
42
V
–
REFM1 REFG1 REF1 REF2 REFG2 REFM2 V
+2
1,8,15,22,31,36
24
21
44
23
2
43
25
27 VOSC
28 C1C
DAC C
30 RFBC
29 OUTC
26 AGNDC
19 VOSD
18 C1D
16 RFBD
DAC D
17 OUTD
20 AGNDD
12
2704 BD
INL (LSB)
GND V
DD
CS/LD SCK
LDAC RFLAG
SRO
U
LTC2704-16
Integral Nonlinearity (INL)
1.0
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
16384
32768
CODE
49152
65535
2704 TA01b
W
U
W
V+/V
–
=
±15V
V
REF
= 5V
±10V
RANGE
ALL 4 DACS
SUPERIMPOSED
2704f
1
LTC2704
ABSOLUTE
MAXIMUM
RATINGS
(Note 1)
PACKAGE/ORDER INFORMATION
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
ORDER PART
NUMBER
LTC2704CGW-16
LTC2704IGW-16
LTC2704CGW-14
LTC2704IGW-14
LTC2704CGW-12
LTC2704IGW-12
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 Options
Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Accuracy
Resolution
Monotonicity
INL
Integral Nonlinearity
DNL
Differential Nonlinearity
GE
Gain Error
Gain Temperature
Coefficient
V
OS
Unipolar Zero-Scale Error
CONDITIONS
The
●
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.
LTC2704-12
MIN TYP MAX
●
●
LTC2704-14
MIN TYP MAX
14
14
LTC2704-16
MIN TYP MAX
16
16
UNITS
Bits
Bits
LSB
LSB
LSB
ppm/°C
µV
µV
µV
µV
12
12
±1
±1
±2
V
REF
= 5V
V
REF
= 5V
V
REF
= 5V
∆Gain/∆Temperature
Span = 0V to 5V, T
A
= 25°C
Span = 0V to 10V, T
A
= 25°C
Span = 0V to 5V
Span = 0V to 10V
●
●
●
●
±0.5
±2
±80
±100
±140
±150
±1
±2
±80
±100
±140
±150
±1
±1
±5
±4
±2
±80
±100
±140
±150
±2
±1
±20
●
●
±200
±300
±400
±600
±200
±300
±400
±600
±200
±300
±400
±600
2
U
W
U
U
W W
W
2704f
LTC2704
ELECTRICAL CHARACTERISTICS
The
●
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 PARAMETER
V
OS
Temperature
Coefficient
BZE
Bipolar Zero
Error
PSRR
Power Supply
Rejection Ratio
CONDITIONS
0V to 5V Range
0V to 10V Range
All Bipolar Ranges
LTC2704-12
MIN TYP MAX
±2
±2
±0.25 ±1
±2
±0.003
±0.006
±0.001 ±0.06
±0.002 ±0.05
3
5
8
●
●
●
●
●
●
●
●
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)
●
LTC2704-14
MIN TYP MAX
±2
±2
±0.5
±2
±2.5
±0.013
±0.025
±0.005 ±0.25
±0.01 ±0.13
3.5
5.5
9
LTC2704-16
MIN TYP MAX
±2
±2
±2
±8
±10
±0.05
±0.1
±0.02
±0.04
4
6
10
±1
±0.5
UNITS
µV/°C
µV/°C
LSB
LSB
LSB/V
LSB/V
LSB/V
LSB/V
µs
µs
µs
V
V
mA
mA
Analog Outputs (Note 4)
Settling Time
I
SC
SR
0V to 5V Range, 5V Step, to
±1LSB
0V to 10V or
±5V
Range,
10V Step, to
±1LSB
±10V
Range, 20V Step, to
±1LSB
Output Swing
V
+
/V
–
=
±15V,
V
REF
=
±7.25V,
0V to 10V Range, I
LOAD
=
±3mA
(Note 2)
V
+
/V
–
=
±5V,
V
REF
=
±2.25V,
0V to 10V Range, I
LOAD
=
±3mA
(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)
Load Regulation V
+
/V
–
=
±15V,
V
REF
= 5V,
0V to 10V Range, Code = 0,
±5mA
Load
(Note 2)
V
+
/V
–
=
±5V,
V
REF
= 2V,
0V to 10V Range, Code = 0,
±3mA
Load
(Note 2)
Output
V
REF
= 5V, 0V to 10V Range,
Impedance
Code = 0,
±5mA
Load
Short-Circuit
V
+
/V
–
=
±16.5V,
V
REF
= 5V,
±10V
Range
Current
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
–
Slew Rate
R
L
= 2k, V
+
/V
–
=
±15V
(Note 2)
R
L
= 2k, V
+
/V
–
=
±5V
(Note 2)
Capacitive Load Within Maximum Load Current
Driving
–14.5
–4.5
14.5
4.5
±5
±3
±0.005
±0.01
–14.5
–4.5
14.5
4.5
±5
±3
±0.01
±0.013
–14.5
–4.5
14.5
4.5
±5
±3
±0.04
LSB/mA
±0.05
LSB/mA
Ω
●
●
0.015
0.006
0.006
●
●
●
●
●
●
38
–36
38
–36
2.2
2.0
3
2.8
1000
–36
2.2
2.0
3
2.8
1000
–36
38
–36
38
–36
2.2
2.0
3
2.8
1000
38
mA
mA
mA
mA
V/µs
V/µs
pF
38
The
●
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
PARAMETER
Reference Inputs
REF1, REF2 Input Voltage
Resistances
R
REF1,
R
REF2
Reference Input Resistance
R
FBx
Output Feedback Resistance
R
VOSX
Offset Adjust Input Resistance
CONDITIONS
V
+
/V
–
=
±15V,
0V to 5V Span (Note 2)
●
●
●
●
MIN
–14.5
5
7
700
TYP
MAX
14.5
UNITS
V
kΩ
kΩ
kΩ
2704f
7
10
1000
3
LTC2704
ELECTRICAL CHARACTERISTICS
The
●
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
PARAMETER
AC Performance (Note 4)
Glitch Impulse
Crosstalk
CONDITIONS
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)
●
●
●
●
●
●
●
MIN
TYP
2
2
3
0.2
0.35
300
250
30
50
0.8
1.2
0.5
17.5
17.0
MAX
UNITS
nV-s
nV-s
nV-s
nV-s
mV
P-P
kHz
kHz
nV/√Hz
nV/√Hz
µV
RMS
µV
RMS
Digital Feedthrough
Multiplying Feedthrough Error
Multiplying Bandwidth
Output Noise Voltage Density
Output Noise Voltage
Power Supply
I
DD
Supply Current, V
DD
I
S
Supply Current, V
+
/V
–
V
DD
Logic Supply Voltage
+
/V
+
V
1 2
Positive Analog Supply Voltage
V
–
Negative Analog Supply Voltage
Digital Inputs/Outputs
V
IH
Digital Input High Voltage
V
IL
V
OH
V
OL
I
IN
C
IN
Digital Input Low Voltage
Digital Output High Voltage
Digital Output Low Voltage
Digital Input Current
Digital Input Capacitance
2.7
4.5
–16.5
2.4
2.0
2
20
18
1
5.5
16.5
– 4.5
µA
mA
mA
mA
V
V
V
V
V
V
V
V
V
µA
pF
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
V
IN
= 0V (Note 3)
●
●
●
●
0.6
0.8
0.4
±1
5
●
V
CC
– 0.4
●
●
●
0.001
TI I G CHARACTERISTICS
range, otherwise specifications are at T
A
= 25°C.
SYMBOL PARAMETER
V
DD
= 4.5V to 5.5V
t
1
SDI Valid to SCK Setup
t
2
SDI Valid to SCK Hold
t
3
SCK High Time
t
4
SCK Low Time
t
5
CS/LD Pulse Width
t
6
LSB SCK High to CS/LD High
t
7
CS/LD Low to SCK Positive Edge
t
8
CS/LD High to SCK Positive Edge
t
9
SRO Propagation Delay
t
10
CLR Pulse Width
4
UW
The
●
denotes specifications which apply over the full operating temperature
CONDITIONS
●
●
●
●
●
●
●
●
MIN
7
7
11
11
9
0
12
12
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
2704f
C
LOAD
= 10pF
●
●
18
50
LTC2704
TI I G CHARACTERISTICS
range, otherwise specifications are at T
A
= 25°C.
SYMBOL
t
11
t
12
t
13
PARAMETER
LDAC Pulse Width
CLR Low to RFLAG Low
CS/LD High to RFLAG High
SCK Frequency
V
DD
= 2.7V to 3.3V
t
1
SDI Valid to SCK Setup
t
2
SDI Valid to SCK Hold
t
3
SCK High Time
t
4
SCK Low Time
t
5
CS/LD Pulse Width
t
6
LSB SCK High to CS/LD High
t
7
CS/LD Low to SCK Positive Edge
t
8
CS/LD High to SCK Positive Edge
t
9
SRO Propagation Delay
t
10
CLR Pulse Width
t
11
LDAC Pulse Width
t
12
CLR Low to RFLAG Low
t
13
CS/LD High to RFLAG High
SCK Frequency
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.
TYPICAL PERFOR A CE CHARACTERISTICS
LTC2704-16
Integral Nonlinearity (INL)
V+/V
–
=
±15V
0.8 V
REF
= 5V
±10V
RANGE
0.6
0.4
DNL (LSB)
1.0
INL (LSB)
INL (LSB)
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
16384
32768
CODE
49152
65535
2704 G01
U W
UW
The
●
denotes specifications which apply over the full operating temperature
CONDITIONS
●
MIN
15
TYP
MAX
50
40
40
C
LOAD
= 10pF (Note 3)
C
LOAD
= 10pF (Note 3)
50% Duty Cycle (Note 5)
●
●
●
●
●
●
●
●
●
●
●
UNITS
ns
ns
ns
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MHz
9
9
15
15
12
0
12
12
26
90
20
70
60
25
C
LOAD
= 10pF
●
●
●
C
LOAD
= 10pF
C
LOAD
= 10pF
50% Duty Cycle (Note 5)
●
●
●
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:
⎛
⎞
1
f
MAX
=
⎜
⎟
, where t
s
is the setup time of the receiving
⎝
2
(
t
9
+
t
S
)
⎠
device.
Differential Nonlinearity (DNL)
V+/V
–
=
±15V
0.8
V
REF
= 5V
±10V
RANGE
0.6
INL vs V
REF
1.0
V+/V
–
=
±15V
0.8
±5V
RANGE
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
MIN
MAX
MAX
1.0
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
16384
32768
CODE
49152
65535
2704 G02
MIN
–1.0
–10 –8 –6 –4 –2 0 2
V
REF
(V)
4
6
8
10
2704 G03
2704f
5
京公网安备 11010802033920号
EEWORLD
