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LTC1450/LTC1450L
Parallel Input, 12-Bit
Rail-to-Rail Micropower
DACs in SSOP
s
Guaranteed Monotonic
s
Buffered True Rail-to-Rail Voltage Output
s
12-Bit Resolution
s
3V Operation (LTC1450L) I
CC
: 250
A Typ
s
5V Operation (LTC1450) I
CC
: 400
A Typ
s
Parallel 12-Bit or 8 + 4-Bit Double Buffered
Digital Input
s
Internal Reference
s
Output Buffer Configurable to Gain of 1 or 2
s
Configurable as a Multiplying DAC
s
Internal Power-On Reset
s
Maximum DNL Error: 0.5LSB
The LTC
1450/LTC1450L are complete single supply, rail-
to-rail voltage output, 12-bit digital-to-analog converters
(DACs) in a 24-pin SSOP or PDIP package. They include an
output buffer amplifier, reference and a double buffered
parallel digital interface.
The LTC1450 operates from a 4.5V to 5.5V supply. The
output can be pin strapped for 4.095V or 2.048V full-scale.
It has a 2.048V internal reference.
The LTC1450L operates from a 2.7V to 5.5V supply. The
output can be pin strapped for 2.5V or 1.22V full-scale. It
has a 1.22V internal reference.
The LTC1450/LTC1450L offer true stand-alone perfor-
mance. In addition, the reference output, high and low
reference inputs and gain setting resistor are brought to
pins for maximum flexibility.
FEATURES
DESCRIPTIO
N
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
s
Digital Calibration
s
Industrial Process Control
s
Automatic Test Equipment
s
Arbitrary Function Generators
s
Battery-Powered Data Conversion Products
s
Feedback Control Loops and Gain Control
APPLICATIO
N
S
U
TYPICAL APPLICATIO
N
U
REFLO
GND
LTC1450:
0V TO 4.095V
LTC1450L:
0V TO 2.5V
LTC1450: 5V
LTC1450L: 3V TO 5V
12-BIT
DAC
REFHI
REFOUT
X1/X2
LTC1450
LTC1450L
1450/50L TA01
V
OUT
V
CC
UPPER
4-BIT
INPUT
LATCH
D11 (MSB)
D8
D7
DATA IN FROM
MICROPROCESSOR
DATA BUS
FROM
MICROPROCESSOR
DECODE LOGIC
FROM
SYSTEM RESET
D0 (LSB)
+
REFERENCE
LTC1450: 2.048V
LTC1450L: 1.22V
12-BIT
DAC
LATCH
POWER-ON
RESET
LDAC
CLR
WR
CSMSB
CSLSB
LOWER
8-BIT
INPUT
LATCH
CODE
0
DNL ERROR (LSB)
0.5
0.0
0.5
1024
2048 2560
1450/50L TA02
512
1536
3072 3584 4095
Differential Nonlinearity
vs Input Code
2
LTC1450/LTC1450L
ABSOLUTE
M
AXI
M
U
M
RATINGS
W
W
W
U
PACKAGE/ORDER I
N
FOR
M
ATIO
N
W
U
U
V
CC
to GND .............................................. 0.5V to 7.5V
Logic Inputs to GND ................................ 0.5V to 7.5V
V
OUT
.............................................. 0.5V to V
CC
+ 0.5V
REFOUT, REFLO, REFHI, X1/X2 ..... 0.5V to V
CC
+ 0.5V
Maximum Junction Temperature .......................... 125
C
Operating Temperature Range
Commercial ........................................... 0
C to 70
C
Industrial ......................................... 40
C to 85
C
Storage Temperature Range ................ 65
C to 150
C
Lead Temperature (Soldering, 10 sec)................. 300
C
ORDER PART
NUMBER
Consult factory for Military grade parts.
T
JMAX
= 125
C,
JA
= 95
C/ W (G)
T
JMAX
= 125
C,
JA
= 58
C/ W (N)
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
DAC
Resolution
q
12
Bits
DNL
Differential Nonlinearity
Guaranteed Monotonic (Note 1)
q
0.5
LSB
INL
Integral Nonlinearity
T
A
= 25
C
3.5
LSB
(Note 1)
q
4.0
LSB
V
OS
Offset Error
T
A
= 25
C
12
mV
q
18
mV
V
OS
TC
Offset Error Temperature Coefficient
15
V/
C
V
FS
Full-Scale Voltage
Using Internal Reference, LTC1450, T
A
= 25
C
4.065
4.095
4.125
V
Using Internal Reference, LTC1450
q
4.045
4.095
4.145
V
External 2.048V Reference, LTC1450
q
4.075
4.095
4.115
V
Using Internal Reference, LTC1450L, T
A
= 25
C
2.470
2.500
2.530
V
Using Internal Reference, LTC1450L
q
2.460
2.500
2.540
V
External 1.22V Reference, LTC1450L
q
2.480
2.500
2.520
V
V
FS
TC
Full-Scale Voltage Temperature Coefficient
Using Internal Reference, LTC1450
0.10
LSB/
C
Using External Reference, LTC1450/LTC1450L
0.02
LSB/
C
Using Internal Reference, LTC1450L
0.10
LSB/
C
Reference Output (REFOUT)
Reference Output Voltage
LTC1450L
q
1.195
1.220
1.245
V
LTC1450
q
2.008
2.048
2.088
V
Reference Output Temperature Coefficient
0.08
LSB/
C
Reference Line Regulation
q
0.7
2
LSB/V
Reference Load Regulation
0
I
OUT
100
A,
LTC1450L
q
0.6
3.0
LSB
LTC1450
q
0.2
1.5
LSB
Short-Circuit Current
REFOUT Shorted to GND
q
80
mA
1
2
3
4
5
6
7
8
9
10
11
12
TOP VIEW
G PACKAGE
24-LEAD PLASTIC SSOP
N PACKAGE
24-LEAD PLASTIC PDIP
24
23
22
21
20
19
18
17
16
15
14
13
WR
CSLSB
CSMSB
(LSB) D0
D1
D2
D3
D4
D5
D6
D7
D8
LDAC
CLR
X1/X2
V
OUT
V
CC
REFOUT
REFHI
REFLO
GND
D11(MSB)
D10
D9
LTC1450CG
LTC1450CN
LTC1450IG
LTC1450IN
LTC1450LCG
LTC1450LCN
LTC1450LIG
LTC1450LIN
V
CC
= 4.5V to 5.5V (LTC1450), 2.7V to 5.5V (LTC1450L), V
OUT
unloaded,
REFOUT = REFHI, REFLO = GND = X1/X2, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
3
LTC1450/LTC1450L
V
CC
= 4.5V to 5.5V (LTC1450), 2.7V to 5.5V (LTC1450L), V
OUT
unloaded,
REFOUT = REFHI, REFLO = GND = X1/X2, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Reference Input (REFLO = GND)
REFHI Input Range
V
REFHI
V
CC
1.5V
q
V
CC
/2
V
REFHI Input Resistance
q
8
18
30
k
REFHI Input Capacitance
15
pF
Power Supply
V
CC
Positive Supply Voltage
For Specified Performance, LTC1450L
q
2.7
5.5
V
LTC1450
q
4.5
5.5
V
I
CC
Supply Current
4.5V
V
CC
5.5V (Note 4) LTC1450
q
300
400
620
A
2.7V
V
CC
5.5V (Note 4) LTC1450L
q
150
250
500
A
Op Amp DC Performance
Short-Circuit Current Low
V
OUT
Shorted to GND
q
100
mA
Short-Circuit Current High
V
OUT
Shorted to V
CC
q
120
mA
Output Impedance to GND
Input Code = 0
q
40
120
AC Performance
Voltage Output Slew Rate
(Note 2)
q
0.5
1.0
V/
s
Voltage Output Settling Time
(Notes 2, 3) to
0.5LSB
14
s
Digital Feedthrough
LDAC = 1
5
(nV)(s)
AC Feedthrough
REFHI = 1kHz, 2V
PP
95
dB
SINAD
Signal-to-Noise + Distortion
REFHI = 1kHz, 2V
PP
(Code: All 1's)
85
dB
Digital Inputs
V
IH
Digital Input High Voltage
V
CC
= 3V, LTC1450L
q
2.2
V
V
CC
= 5V, LTC1450
q
2.4
V
V
IL
Digital Input Low Voltage
V
CC
= 3V, LTC1450L
q
0.8
V
V
CC
= 5V, LTC1450
q
0.8
V
V
LTH
Logic Threshold Voltage
LTC1450L
V
CC
/2
V
I
LEAK
Digital Input Leakage
V
CC
= 5V, V
IN
= GND to V
CC
q
10
10
A
C
IN
Digital Input Capacitance
Guaranteed by Design. Not Subject to Test
q
10
pF
4
LTC1450/LTC1450L
ELECTRICAL CHARACTERISTICS
V
CC
= 4.5V to 5.5V (LTC1450), V
CC
= 2.7V to 3.6V (LTC1450L), T
A
= T
MIN
to T
MAX
, unless otherwise noted.
TYPICAL PERFOR
M
A
N
CE CHARACTERISTICS
U
W
LOAD CURRENT (mA)
4.4
LTC1450 MINIMUM SUPPLY VOLTAGE (V)
LTC1450L MINIMUM SUPPLY VOLTAGE (V)
4.8
5.0
5.4
5.8
0.01
1
10
100
1450/50L G01
4.0
0.1
5.2
4.6
4.2
5.6
2.8
3.2
3.4
3.8
4.2
2.4
3.6
3.0
2.6
4.0
V
OUT
< 1LSB
LTC1450
LTC1450L
Minimum Supply Voltage
vs Load Current
TEMPERATURE (
C)
55
350
SUPPLY CURRENT (
A)
360
380
390
400
450
420
15
25
45
125
1450/50L G02
370
430
440
410
35
5
65
85 105
V
CC
= 5.5V
V
CC
= 4.5V
V
CC
= 5V
LOGIC INPUT VOLTAGE (V)
0
0.5 1.0 1.5 2.0
3.0
4.0
3.5
4.5
SUPPLY CURRENT (mA)
6
8
1450/50L G03
4
2
0
7
5
3
1
2.5
5.0
V
CC
= 5V
ALL LOGIC INPUTS
TIED TOGETHER
LTC1450
LTC1450L
LTC1450 Supply Current
vs Temperature
Supply Current
vs Logic Input Voltage
The
q
denotes specifications which apply over the full operating
temperature range.
Note 1: Nonlinearity is defined from the first code that is greater than or
equal to the maximum offset specification to code 4095 (full-scale).
Note 2: Load is 5k
in parallel with 100pF.
Note 3: DAC switched all 1's and the code corresponding to V
OS(MAX)
for
the part.
Note 4: Digital inputs at 0V or V
CC
.
Note 5: Digital inputs swing 10% to 90% of V
CC
, t
r
= t
f
= 5ns and timing
measurements are from V
CC
/2.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Switching Characteristics (Note 5)
t
CS
CS (MSB or LSB) Pulse Width
q
40
ns
t
WR
WR Pulse Width
q
40
ns
t
CWS
CS to WR Setup
q
0
ns
t
CWH
CS to WR Hold
q
0
ns
t
DWS
Data Valid to WR Setup
V
CC
= 4.5V to 5.5V (LTC1450)
q
40
15
ns
V
CC
= 2.7V to 3.6V (LTC1450L)
q
40
15
ns
V
CC
= 5V (LTC1450L)
10
ns
t
DWH
Data Valid to WR Hold
V
CC
= 4.5V to 5.5V (LTC1450)
q
0
10
ns
V
CC
= 2.7V to 3.6V (LTC1450L)
q
0
10
ns
V
CC
= 5V (LTC1450L)
5
ns
t
LDAC
LDAC Pulse Width
q
40
ns
t
CLR
CLR Pulse Width
q
40
ns
5
LTC1450/LTC1450L
TYPICAL PERFOR
M
A
N
CE CHARACTERISTICS
U
W
LOGIC INPUT VOLTAGE (V)
0
0.3 0.6 0.9 1.2
SUPPLY CURRENT (
A) 1200
1600
1450/50L G04
800
400
0
1400
1000
600
200
1.5 1.8 2.1 2.4 2.7 3.0
V
CC
= 3V
ALL LOGIC INPUTS
TIED TOGETHER
LTC1450L Supply Current
vs Logic Input Voltage
LTC1450 Output Swing
vs Load Resistance
LOAD RESISTANCE (
)
10
OUTPUT SWING (V)
100
1k
10k
1450/50L G05
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
FULL SCALE
R
L
TIED TO GND
ZERO SCALE
R
L
TIED TO V
CC
V
CC
= 5V
OUTPUT SINK CURRENT (mA)
OUTPUT PULL-DOWN VOLTAGE (mV)
1000
100
10
1
0.1
0.0001
0.1
1
10
100
1450/50L G06
0.001
0.01
125
C
55
C
25
C
LTC1450 Pull-Down Voltage vs
Output Sink Current Capability
LTC1450 Output Offset Voltage
vs Temperature
LTC1450
Integral Nonlinearity (INL)
TEMPERATURE (
C)
55
0
OUTPUT OFFSET VOLTAGE (mV)
0.5
1.5
2.0
2.5
5.0
3.5
15
25
45
125
1450/50L G07
1.0
4.0
4.5
3.0
35
5
65
85 105
LTC1450
Differential Nonlinearity (DNL)
CODE
0
0.2
DNL ERROR (LSB)
0
0.2
1024
2048 2560
1450/50L G08
512
1536
3072 3584 4095
CODE
0
2
ERROR (LSB)
0
2
1024
2048 2560
1450/50L G09
512
1536
3072 3584 4095
LTC1450
Broadband Output Noise
LTC1450 Total Harmonic
Distortion + Noise vs Frequency
FREQUENCY (Hz)
20
PSRR (dB)
30
50
60
80
90
10
100
10k
10M
1450/50L G10
10
1
1k
70
40
0
REFOUT
V
OUT
CODE = FFF
H
Power Supply Rejection
vs Frequency
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION + NOISE (dB)
40
50
60
70
80
90
100
100
10k
100k
1450/50L G11
1k
V
CC
= 5V
V
REFHI
= 2V
P-P
V
OUT
= 4V
P-P
5ms/DIV
1mV/DIV
1450/50L G12
CODE = FFF
H
X1/X2 = GND
BW = 3Hz to 1.2MHz
TOTAL = 0.35mV
RMS
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