LTC1657/LTC1657L
Parallel 16-Bit Rail-to-Rail
Micropower DAC
FEATURES
s
s
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s
s
s
DESCRIPTIO
s
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s
16-Bit Monotonic Over Temperature
Deglitched Rail-to-Rail Voltage Output: 8nV•s
I
CC
: 650µA Typ
Maximum DNL Error:
±1LSB
Settling Time: 20µs to
±1LSB
Built-In Reference: 2.048V (LTC1657)
1.25V (LTC1657L)
Internal Power-On Reset to Zero Volts
Asynchronous CLR Pin
Output Buffer Configurable for Gain of 1 or 2
Parallel 16-Bit or 2-Byte Double Buffered Interface
Narrow 28-Lead SSOP Package
Multiplying Capability
The LTC
®
1657/LTC1657L are complete single supply, rail-
to-rail voltage output, 16-bit digital-to-analog converters
(DAC) in a 28-pin SSOP or PDIP package. They include a
rail-to-rail output buffer amplifier, an internal reference
and a double buffered parallel digital interface.
The LTC1657/LTC1657L have separate reference input
pins that can be driven by an external reference. The full-
scale output can be 1 or 2 times the reference voltage
depending on how the X1/X2 pin is connected. The LTC1657
operates from a 4.5V to 5.5V supply and has an onboard
2.048V reference. The LTC1657L operates from a 2.7V to
5.5V supply and has an onboard 1.25V reference.
The LTC1657/LTC1657L are similar to Linear Technol-
ogy Corporation’s LTC1450/LTC1450L 12-bit V
OUT
DAC
family, allowing an upgrade path. They are the only
buffered 16-bit parallel DACs in a 28-lead SSOP package
and include an onboard reference for stand alone
performance.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
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Instrumentation
Digital Calibration
Industrial Process Control
Automatic Test Equipment
Communication Test Equipment
BLOCK DIAGRA
19 D15 (MSB)
18
17
16
15
14
13
12
DATA IN FROM
MICROPROCESSOR
DATA BUS
D8
11 D7
10
9
8
7
6
5
4 D0 (LSB)
3 CSMSB
FROM
MICROPROCESSOR
DECODE LOGIC
1 WR
2 CSLSB
28 LDAC
FROM
SYSTEM RESET
27 CLR
LTC1657: 4.5V TO 5.5V
LTC1657L: 2.7V TO 5.5V
23
REFOUT
REFERENCE
LTC1657: 2.048V
LTC1657L: 1.25V
MSB
8-BIT
INPUT
REGISTER
22
REFHI
24
V
CC
16-BIT
DAC
REGISTER
16-BIT
DAC
+
–
V
OUT
25
LTC1657:
0V TO 4.096V
LTC1657L:
0V TO 2.5V
DIFFERENTIAL NONLINEARITY (LSB)
LSB
8-BIT
INPUT
REGISTER
R
R
POWER-ON
RESET
GND
20
REFLO
21
X1/X2
26
1657 TA01
U
Differential Nonlinearity
vs Input Code
1.0
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
16384
32768
49152
DIGITAL INPUT CODE
65535
1657 TA02
W
U
1
LTC1657/LTC1657L
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
WR
CSLSB
CSMSB
(LSB) D0
D1
D2
D3
D4
D5
1
2
3
4
5
6
7
8
9
28 LDAC
27 CLR
26 X1/X2
25 V
OUT
24 V
CC
23 REFOUT
22 REFHI
21 REFLO
20 GND
19 D15 (MSB)
18 D14
17 D13
16 D12
15 D11
GN PACKAGE
28-LEAD PLASTIC SSOP
V
CC
to GND .............................................. – 0.5V to 7.5V
TTL Input Voltage, REFHI, REFLO,
X1/X2 ....................................................... – 0.5V to 7.5V
V
OUT
, REFOUT ............................ – 0.5V to (V
CC
+ 0.5V)
Operating Temperature Range
LTC1657C/LTC1657LC .......................... 0°C to 70°C
LTC1657I/LTC1657LI ...................... – 40°C to 85°C
Maximum Junction Temperature .......................... 125°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
LTC1657CGN
LTC1657CN
LTC1657IGN
LTC1657IN
LTC1657LCGN
LTC1657LCN
LTC1657LIGN
LTC1657LIN
D6 10
D7 11
D8 12
D9 13
D10 14
N PACKAGE
28-LEAD PDIP
T
JMAX
= 125°C,
θ
JA
= 95°C/ W (GN)
T
JMAX
= 125°C,
θ
JA
= 58°C/ W (N)
Consult factory for parts specified with wider operating temperature ranges.
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 4.5V to 5.5V (LTC1657), V
CC
= 2.7V to 5.5V (LTC1657L),
V
OUT
unloaded, REFOUT tied to REFHI, REFLO tied to GND, X1/X2 tied to GND, unless otherwise noted.
SYMBOL
PARAMETER
Resolution
Monotonicity
DNL
INL
ZSE
V
OS
V
OS
TC
Differential Nonlinearity
Integral Nonlinearity
Zero Scale Error
Offset Error
Offset Error Tempco
Gain Error
Gain Error Drift
Power Supply
V
CC
I
CC
Positive Supply Voltage
Supply Current
For Specified Performance (LTC1657)
For Specified Performance (LTC1657L)
(Note 4)
q
q
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
q
q
MIN
16
16
TYP
MAX
UNITS
Bits
Bits
DAC (Note 2)
Guaranteed Monotonic (Note 3)
(Note 3)
Measured at Code 200 (LTC1657)
Measured at Code 200 (LTC1657L)
q
q
q
q
q
±0.5
±4
0
±0.3
±0.4
±5
±2
0.5
1.0
4.5
2.7
650
±1
±12
2
±3
±4
±16
LTC1657
LTC1657L
ppm/°C
ppm/°C
5.5
5.5
1200
V
V
µA
2
U
LSB
LSB
mV
mV
mV
µV/°C
LSB
W
U
U
W W
W
LTC1657/LTC1657L
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 4.5V to 5.5V (LTC1657), V
CC
= 2.7V to 5.5V (LTC1657L),
V
OUT
unloaded, REFOUT tied to REFHI, REFLO tied to GND, X1/X2 tied to GND, unless otherwise noted.
SYMBOL
PARAMETER
Short-Circuit Current Low
Short-Circuit Current High
Output Impedance to GND
Output Line Regulation
AC Performance
Voltage Output Slew Rate
Voltage Output Settling Time
Digital Feedthrough
Midscale Glitch Impulse
Output Voltage Noise Using
Internal Reference at 1kHz
Output Voltage Noise Using
External Reference at 1kHz
Output Voltage Noise Density Using
Internal Reference from 0.1Hz to 10Hz
Refererence Input Multiplying BW
Reference Output (REFOUT)
Reference Output Voltage
Reference Output
Temperature Coefficient
Reference Line Regulation
Reference Load Regulation
Short-Circuit Current
Reference Output Voltage Noise at 1kHz
Reference Output Voltage Noise Density
from 0.1Hz to 10Hz
Reference Input
REFHI, REFLO Input Range
(Note 7) See Applications Information
X1/X2 Tied to V
OUT
X1/X2 Tied to GND
LTC1657
LTC1657L (Relative to REFLO)
q
q
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
V
OUT
Shorted to GND
V
OUT
Shorted to V
CC
Input Code = 0 (LTC1657)
Input Code = 0 (LTC1657L)
Input Code = 65535, LTC1657: V
CC
= 4.5V to 5.5V
Input Code = 65535, LTC1657L: V
CC
= 2.7V to 5.5V
(Note 5)
(Note 5) to 0.0015% (16-Bit Settling Time)
(Note 5) to 0.012% (13-Bit Settling Time)
(Note 6)
DAC Switch Between 8000
H
and 7FFF
H
X1/X2 Tied to V
OUT
(Notes 8, 9)
LTC1657
LTC1657L
X1/X2 Tied to V
OUT
(Notes 8, 9, 10)
X1/X2 Tied to V
OUT
(Notes 8, 9)
q
q
q
q
q
q
MIN
TYP
70
80
40
120
MAX
120
140
120
275
4
3
UNITS
mA
mA
Ω
Ω
mV/V
mV/V
V/µs
µs
µs
nV •s
nV •s
nV/√Hz
nV/√Hz
nV/√Hz
µV
P-P
kHz
Op Amp DC Performance
q
±0.3
±0.7
20
10
0.3
8
165
105
50
8
700
LTC1657
LTC1657L
q
q
2.036
1.240
2.048
1.250
15
2.060
1.260
V
V
ppm/°C
LTC1657: V
CC
= 4.5V to 5.5V
LTC1657L: V
CC
= 2.7V to 5.5V
Measured at I
OUT
= 100µA (LTC1657)
Measured at I
OUT
= 100µA (LTC1657L)
REFOUT Shorted to GND
LTC1657
LTC1657L
q
q
q
q
q
±1.5
±1.0
5
3
50
150
90
6
100
mV/V
mV/V
mV/A
mV/A
mA
nV/√Hz
nV/√Hz
µV
P-P
0
0
16
16
25
23
V
CC
– 1.5
V
CC
/2
V
V
kΩ
kΩ
REFHI Input Resistance
3
LTC1657/LTC1657L
The
q
denotes specifications which apply over the full operating
temperature range T
A
= T
MIN
to T
MAX
. V
CC
= 5V (LTC1657), V
CC
= 3V (LTC1657L), unless otherwise noted.
SYMBOL
Digital I/O
V
IH
V
IL
I
LEAK
C
IN
t
CS
t
WR
t
CWS
t
CWH
t
DWS
t
DWH
t
LDAC
t
CLR
Digital Input High Voltage
Digital Input Low Voltage
Digital Input Leakage
Digital Input Capacitance
CS (MSB or LSB) Pulse Width
WR Pulse Width
CS to WR Setup
CS to WR Hold
Data Valid to WR Setup
Data Valid to WR Hold
LDAC Pulse Width
CLR Pulse Width
V
IN
= GND to V
CC
(Note 7)
q
q
q
q
ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
2.4
LTC1657
TYP
MAX
MIN
2.0
LTC1657L
TYP
MAX
UNITS
V
0.8
±10
10
40
40
0
0
40
0
40
40
60
60
0
0
60
0
60
60
0.6
±10
10
V
µA
pF
ns
ns
ns
ns
ns
ns
ns
ns
Switching Characteristics
q
q
q
q
q
q
q
q
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
External reference REFHI = 2.2V. V
CC
= 5V (LTC1657).
External reference REFHI = 1.3V. V
CC
= 3V (LTC1657L).
Note 3:
Nonlinearity is defined from code 128 to code 65535 (full scale).
See Applications Information.
Note 4:
Digital inputs at 0V or V
CC
.
Note 5:
DAC switched between all 1s and all 0s. V
FS
= 4.096V.
Note 6:
D0 to D15 toggle between all 0s and all 1s with REFHI = 0V,
CSMSB = CSLSB = WR = LDAC = High
Note 7:
Guaranteed by design. Not subject to test.
Note 8:
DAC inputs all 1s.
Note 9:
X1/X2 tied to GND, the voltage noise will be a factor of 2 greater.
Note 10:
Using 2.048V (1.25V) external reference with 3nV/√Hz noise at
1kHz for LTC1657/(LTC1657L).
4
LTC1657/LTC1657L
TYPICAL PERFOR A CE CHARACTERISTICS
LTC1657 Differential Nonlinearity
2.0
DIFFERENTIAL NONLINEARITY (LSB)
DIFFERENTIAL NONLINEARITY (LSB)
1.6
1.2
0.8
0.4
0
–0.4
–0.8
–1.2
–1.6
–2.0
0
16384
32768
49152
DIGITAL INPUT CODE
65535
1657 G01
1.2
0.8
0.4
0
–0.4
–0.8
–1.2
–1.6
–2.0
0
32768
16384
49152
DIGITAL INPUT CODE
65535
1657 G02
INTEGRAL NONLINEARITY (LSB)
LTC1657L Integral Nonlinearity
5
4
INTEGRAL NONLINEARITY (LSB)
3
2
V
CC
– V
OUT
(V)
1
0
–1
–2
–3
–4
–5
0
32768
16384
49152
DIGITAL INPUT CODE
65535
1657 G04
1.2
1.0
0.8
0.6
0.4
0.2
0
0
5
LOAD CURRENT (mA)
10
1657 G05
V
CC
– V
OUT
(V)
LTC1657 Minimum Output
Voltage vs Output Sink Current
1.2
OUTPUT PULL-DOWN VOLTAGE (V)
1.0
125°C
0.8
0.6
25°C
0.4
0.2
0
–55°C
OUTPUT PULL-DOWN VOLTAGE (V)
CODE ALL 0s
∆V
OUT
≤
1LSB
0.6
0.4
FULL-SCALE VOLTAGE (V)
0
5
10
OUTPUT SINK CURRENT (mA)
U W
1657 G07
LTC1657L Differential Nonlinearity
2.0
1.6
LTC1657 Integral Nonlinearity
5
4
3
2
1
0
–1
–2
–3
–4
–5
0
16384
32768
49152
DIGITAL INPUT CODE
65535
1657 G03
LTC1657 Minimum Supply
Headroom for Full Output Swing
vs Load Current
2.0
1.8
1.6
1.4
CODE ALL 1s
∆V
OUT
≤
1LSB
V
OUT
= 4.096V
125°C
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
–55°C
0.2
0
LTC1657L Minimum Supply
Headroom for Full Output Swing
vs Load Current
CODE ALL 1s
∆V
OUT
≤
1LSB
V
OUT
= 2.5V
125°C
25°C
25°C
–55°C
0
5
LOAD CURRENT (mA)
10
1657 G06
LTC1657L Minimum Output
Voltage vs Output Sink Current
4.110
125°C
25°C
–55°C
4.105
4.100
4.095
4.090
4.085
LTC1657 Full-Scale Voltage
vs Temperature
0.2
CODE ALL 0s
∆V
OUT
≤
1LSB
0
0
5
10
OUTPUT SINK CURRENT (mA)
15
1657 G08
15
4.080
–55
–25
5
35
65
TEMPERATURE (°C)
95
125
1657 G09
5
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