LTC1458/LTC1458L
Quad 12-Bit Rail-to-Rail
Micropower DACs
FEATURES
s
s
s
s
s
s
s
s
DESCRIPTIO
s
s
s
s
Quad 12-Bit DAC
Buffered True Rail-to-Rail Voltage Output
Maximum DNL Error: 0.5LSB
5V Operation, I
CC
: 1.1mA Typ (LTC1458)
3V Operation, I
CC
: 800µA Typ (LTC1458L)
Internal or External Reference Operation
Settling Time: 14µs to
±0.5LSB
Schmitt Trigger On Clock Input Allows Direct
Optocoupler Interface
Power-On Reset and CLR Pin
SSOP-28 Package
3-Wire Cascadable Serial Interface with 250kHz
Update Rate
Low Cost
The LTC
®
1458/LTC1458L are complete single supply,
quad rail-to-rail voltage output, 12-bit digital-to-analog
converters (DACs) in SO-28 and SSOP-28 packages. They
include an output buffer amplifier with variable gain (×1 or
×
2) and an easy-to-use 3-wire cascadable serial interface.
The LTC1458 has an onboard reference of 2.048V and a
full-scale output of 4.095V in a
×
2 gain configuration. It
operates from a single 4.5V to 5.5V supply dissipating
only 5.5mW (I
CC
= 1.1mA typ).
The LTC1458L has an onboard 1.22V reference and a full-
scale output of 2.5V in a
×2
gain configuration. It operates
from a single supply of 2.7V to 5.5V dissipating 2.4mW.
Excellent DNL, low supply current and a wide range of
built-in functions allow these parts to be used in a host of
applications when flexibility, power and single supply
operation are important.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
s
s
s
Digital Calibration
Industrial Process Control
Automatic Test Equipment
Low Power Systems
TYPICAL APPLICATIO
Control Outputs
Daisy-Chained
Functional Block Diagram: Quad 12-Bit Rail-to-Rail DAC
2.048V (LTC1458)
1.22V (LTC1458L)
REFOUT
REFHI C
FROM
µP
5V (LTC1458)
3V TO 5V (LTC1458L)
D
IN
V
CC
0.5
CS/LD CLK
REFHI B
V
OUT C
X1/X2 C
REFLO C
REFHI D
V
OUT D
X1/X2 D
REFLO D
DAC C
48-BIT
SHIFT REGISTER
AND
DAC REGISTER
DAC D
DAC B
V
OUT B
DNL (LSB)
X1/X2 B
REFLO B
REFHI A
DAC A
V
OUT A
X1/X2 A
REFLO A
CLR
D
OUT
1458 BD01
U
Differential Nonlinearity
vs Input Code
0.4
0.3
0.2
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
0
512 1024 1536 2048 2560 3072 3584 4095
CODE
1458 G09
U
U
1
LTC1458/LTC1458L
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
X1/X2 C
V
OUT C
CS/LD
D
IN
REFHI C
GND
REFLO C
REFLO D
REFHI D
1
2
3
4
5
6
7
8
9
28 V
CC
27 X1/X2 B
26 V
OUT B
25 CLR
24 REFHI B
23 GND
22 REFLO B
21 REFLO A
20 REFHI A
19 REFOUT
18 NC
17 V
OUT A
16 X1/X2 A
15 V
CC
SW PACKAGE
28-LEAD PLASTIC SO
V
CC
to GND .............................................. – 0.5V to 7.5V
Logic Inputs to GND ................................ – 0.5V to 7.5V
V
OUT A
, V
OUT B
, V
OUT C
, V
OUT D
,
X1/X2 A , X1/X2 B, X1/X2 C,
X1/X2 D ......................................... – 0.5V to V
CC
+ 0.5V
REFHI A , REFHI B, REFHI C, REFHI D,
REFLO A , REFLO B, REFLO C,
REFLO D ........................................ – 0.5V to V
CC
+ 0.5V
Maximum Junction Temperature ......................... 125°C
Operating Temperature Range
LTC1458C/LTC1458LC ............................ 0°C to 70°C
LTC1458I/LTC1458LI ........................ – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
LTC1458CG
LTC1458CSW
LTC1458LCG
LTC1458LCSW
LTC1458IG
LTC1458ISW
LTC1458LIG
LTC1458LISW
D
OUT
10
CLK 11
NC 12
V
OUT D
13
X1/X2 D 14
G PACKAGE
28-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 100°C/W (G)
T
JMAX
= 125°C,
θ
JA
= 150°C/W (SW)
Consult factory for Military grade parts.
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= T
MIN
to T
MAX
. V
CC
= 4.5V to 5.5V (LTC1458), 2.7V to 5.5V (LTC1458L),
X1/X2 = REFLO = GND, REFHI = REFOUT, V
OUT
unloaded, unless otherwise noted.
SYMBOL
DAC
Resolution
DNL
INL
V
OS
V
OS
TC
V
FS
Differential Nonlinearity
Integral Nonlinearity
Offset Error
Offset Error Temperature
Coefficient
Full-Scale Voltage
When Using Internal Reference, LTC1458, T
A
= 25°C
LTC1458
When Using Internal Reference, LTC1458L, T
A
= 25°C
LTC1458L
V
FS
TC
Reference
Reference Output Voltage
Reference Output
Temperature Coefficient
Reference Line Regulation
Reference Load Regulation
Reference Input Range
Reference Input Resistance
0
≤
I
OUT
≤
100µA, LTC1458
LTC1458L
V
REFHI
≤
V
CC
– 1.5V
q
q
q
q
q
q
q
ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
12
TYP
MAX
UNITS
Bits
Guaranteed Monotonic (Note 2)
T
A
= 25°C
(Note 2)
T
A
= 25°C
q
q
q
±0.5
±1.75
±2.25
±3.0
±6.0
±15
4.065
4.045
2.470
2.460
4.095
4.095
2.500
2.500
±
24
4.125
4.145
2.530
2.540
±4.0
±4.5
±12
±18
Full-Scale Voltage
Temperature Coefficient
When Using Internal Reference
ppm/°C
LTC1458
LTC1458L
q
q
2.008
1.195
2.048
1.220
±20
0.7
0.2
0.6
V
CC
/2
2.088
1.245
ppm/°C
±2.0
1.5
3.0
40
LSB/V
LSB
LSB
V
kΩ
15
24
2
U
LSB
LSB
LSB
mV
mV
µV/°C
V
V
V
V
V
V
W
U
U
W W
W
LTC1458/LTC1458L
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= T
MIN
to T
MAX
. V
CC
= 4.5V to 5.5V (LTC1458), 2.7V to 5.5V (LTC1458L),
X1/X2 = REFLO = GND, REFHI = REFOUT, V
OUT
unloaded, unless otherwise noted.
SYMBOL
PARAMETER
Reference Input Capacitance
Short-Circuit Current
Power Supply
V
CC
I
CC
Positive Supply Voltage
Supply Current
For Specified Performance, LTC1458
LTC1458L
4.5V
≤
V
CC
≤
5.5V (Note 5) , LTC1458
2.7V
≤
V
CC
≤
5.5V (Note 5), LTC1458L
V
OUT
Shorted to GND
V
OUT
Shorted to V
CC
Input Code = 0
(Note 3)
(Notes 3, 4) to
±0.5LSB
REFHI = 1kHz, 2V
P-P
, (Code: All 0s)
REFHI = 1kHz, 2V
P-P
, (Code: All 1s)
q
q
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
MIN
q
TYP
15
45
MAX
120
5.5
5.5
UNITS
pF
mA
V
V
µA
µA
mA
mA
Ω
V/µs
µs
nV • s
dB
dB
REFOUT Shorted to GND
4.5
2.7
1100
800
60
70
40
0.5
1.0
14
0.3
– 95
85
2400
2000
120
120
160
Op Amp DC Performance
Short-Circuit Current Low
Short-Circuit Current High
Output Impedance to GND
AC Performance
Voltage Output Slew Rate
Voltage Output Settling Time
Digital Feedthrough
AC Feedthrough
SINAD
Signal-to-Noise + Distortion
q
q
q
q
The
q
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at
T
A
= T
MIN
to T
MAX
. V
CC
= 5V (LTC1458), 3V (LTC1458L), unless otherwise noted.
SYMBOL
Digital I/O
V
IH
V
IL
V
OH
V
OL
I
LEAK
C
IN
Switching
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
D
IN
Valid to CLK Setup
D
IN
Valid to CLK Hold
CLK High Time
CLK Low Time
CS/LD Pulse Width
LSB CLK to CS/LD
CS/LD Low to CLK
D
OUT
Output Delay
CLK Low to CS/LD Low
C
LOAD
= 15pF
q
q
q
q
q
q
q
q
q
PARAMETER
Digital Input High Voltage
Digital Input Low Voltage
Digital Output High Voltage
Digital Output Low Voltage
Digital Input Leakage
Digital Input Capacitance
CONDITIONS
q
q
MIN
2.4
LTC1458
TYP
MAX
MIN
2.0
LTC1458L
TYP
MAX
UNITS
V
0.8
V
CC
– 1.0
0.4
±10
10
V
CC
– 0.7
0.6
0.4
±10
10
V
V
V
µA
pF
I
OUT
= – 1mA
I
OUT
= 1mA
V
IN
= GND to V
CC
Guaranteed by Design,
Not Subject to Test
q
q
q
q
40
0
40
40
50
40
20
150
20
60
0
60
60
80
60
30
220
30
ns
ns
ns
ns
ns
ns
ns
ns
ns
3
LTC1458/LTC1458L
ELECTRICAL CHARACTERISTICS
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
Nonlinearity is defined from the first code that is greater than or
equal to the maximum offset specification to code 4095 (full scale).
Note 3:
Load is 5kΩ in parallel with 100pF.
Note 4:
DAC switched between all 1s and the code corresponding to V
OS
for the part.
Note 5:
Digital inputs at 0V or V
CC
.
TYPICAL PERFOR A CE CHARACTERISTICS
LTC1458
Differential Nonlinearity (DNL)
0.5
0.4
0.3
INL ERROR (LSB)
0.2
DNL (LSB)
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
0
512 1024 1536 2048 2560 3072 3584 4095
CODE
1458 G09
0.4
0
–0.4
–0.8
–1.2
–1.6
–2.0
0
512 1024 1536 2048 2560 3072 3584 4095
CODE
1458 G08
V
CC
– V
OUT
(V)
Minimum Output Voltage vs
Output Sink Current
1000
OUTPUT PULL-DOWN VOLTAGE (mV)
REFLO = GND
900 X1/X2 = GND
800
700
600
500
400
300
200
100
0.1
0
5
10
15
20
25
OUTPUT SINK CURRENT (mA)
30
1458 G04
25°C
OUTPUT SWING (V)
125°C
–55°C
3.0
2.5
2.0
1.5
1.0
0.5
0
10
REFLO = GND
X1/X2 = GND
DAC CODE = FFF
H
100
1k
LOAD RESISTANCE (Ω)
10k
1458 G05A
OUTPUT SWING (V)
4
U W
LTC1458
Integral Nonlinearity (INL)
2.0
1.6
1.2
0.8
1.0
0.8
0.6
0.4
0.2
0
1.4
1.2
Minimum Supply Headroom for
Full Output Swing vs Load Current
∆V
OUT
< 1LSB
REFLO = GND
X1/X2 = GND
CODE: ALL 1's
V
OUT
= 4.095V
0
5
10
15
20
LOAD CURRENT (mA)
25
30
1458 G03
Output Swing vs Load Resistance
4.5
4.0
3.5
4.5
4.0
3.5
3.0
Output Swing vs Load Resistance
REFLO = GND
X1/X2 = GND
DAC CODE = OOO
H
V
CC
2.5
2.0
1.5
1.0
0.5
0
10
R
L
R
L
100
1k
LOAD RESISTANCE (Ω)
10k
1458 G06A
LTC1458/LTC1458L
TYPICAL PERFOR A CE CHARACTERISTICS
LTC1458 Full-Scale Voltage vs
Temperature
4.110
4.105
5
4
SFULL-SCALE VOLTAGE (V)
SUPPLY CURRENT (µA)
OFFSET VOLTAGE (mV)
4.100
4.095
4.090
4.085
4.080
–55
–25
5
35
65
TEMPERATURE (°C)
PI FU CTIO S
X1/X2 C, X1/X2 D,X1/X2 A, X1/X2 B (Pins 1, 14, 16, 27):
The Input Pin that Sets the Gain for DAC C/D/A/B. When
grounded the gain will be 2, i.e., output full-scale will be
2 • REFHI. When connected to V
OUT
the gain will be 1, i.e.,
output full-scale will be equal to REFHI.
V
OUT C
, V
OUT D
, V
OUT A
, V
OUT B
(Pins 2, 13, 17, 26):
The
Buffered DAC Outputs.
CS/LD (Pin 3):
The Serial Interface Enable and Load
Control Input.
D
IN
(Pin 4):
The Serial Data Input.
REFHI C, REFHI D, REFHI A, REFHI B,(Pins 5, 9, 20, 24):
The Inputs to the DAC Resistor Ladder for DAC C/D/A/B.
GND (Pins 6, 23):
Ground.
REFLO C, REFLO D, REFLO A, REFLO B, (Pins 7, 8, 21,
22):
The Bottom of the DAC Resistor Ladders for the
DACs. These can be used to offset zero-scale above
ground. REFLO should be connected to ground when no
offset is required.
D
OUT
(Pin 10):
The Output of the Shift Register which
Becomes Valid on the Rising Edge of the Serial Clock.
CLK (Pin 11):
The Serial Interface Clock Input.
V
CC
(Pins 15, 28):
The Positive Supply Input. 4.5V
≤
V
CC
≤
5.5V (LTC1458), 2.7V
≤
V
CC
≤
5.5V (LTC1458L). Re-
quires a 0.1µF bypass capacitor to ground.
REFOUT (Pin 19):
The Output of the Internal Reference.
CLR (Pin 25):
The Clear Pin. Clears all DACs to zero-scale
when pulled low.
U W
95
LTC1458
Offset Voltage vs Temperature
950
940
930
920
910
900
890
880
870
860
–25
35
65
5
TEMPERATURE (°C)
95
125
1458 G07
LTC1458
Supply Current vs Temperature
3
2
1
0
–1
–2
–3
–4
125
1458 G06
V
CC
= 5.5V
V
CC
= 5V
V
CC
= 4.5V
–5
–55
850
–55
–25
35
65
5
TEMPERATURE (°C)
95
125
1458 G05
U
U
U
5
测试/测量
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