LTC1655/LTC1655L
16-Bit Rail-to-Rail
Micropower DACs in
SO-8 Package
FEATURES
s
s
s
s
s
DESCRIPTIO
s
s
s
s
s
s
s
16-Bit Monotonicity Over Temperature
Deglitched Rail-to-Rail Voltage Output
SO-8 Package
I
CC(TYP)
: 600µA
Internal Reference: 2.048V (LTC1655)
1.25V (LTC1655L)
Maximum DNL Error:
±1LSB
Settling Time: 20µS to
±1LSB
750kHz Max Update Rate
Power-On Reset to Zero Volts
3-Wire Cascadable Serial Interface
Low Cost
Pin Compatible Upgrade for LTC1451 12-Bit DAC
Family
The LTC
®
1655/LTC1655L are rail-to-rail voltage output,
16-bit digital-to-analog converters in an SO-8 package.
They include an output buffer and a reference. The 3-wire
serial interface is compatible with SPI/QSPI and
MICROWIRE
TM
protocols. The CLK input has a Schmitt
trigger that allows direct optocoupler interface.
The LTC1655 has an onboard 2.048V reference that can be
overdriven to a higher voltage. The output swings from 0V
to 4.096V when using the internal reference. The typical
power dissipation is 3.0mW on a single 5V supply.
The LTC1655L has an onboard 1.25V reference that can be
overdriven to a higher voltage. The output swings from 0V
to 2.5V when using the internal reference. The typical
power dissipation is 1.8mW on a single 3V supply.
The LTC1655/LTC1655L are pin compatible with Linear
Technology’s 12-bit V
OUT
DAC family, allowing an easy
upgrade path. They are the only buffered 16-bit DACs in
an SO-8 package and they include an onboard reference
for standalone performance.
, LTC and LT are registered trademarks of Linear Technology Corporation.
MICROWIRE is a trademark of National Semiconductor Corporation.
APPLICATIO S
s
s
s
s
Digital Calibration
Industrial Process Control
Automatic Test Equipment
Cellular Telephones
FU CTIO AL BLOCK DIAGRA
LTC1655: 4.5V TO 5.5V
LTC1655L: 2.7V TO 5.5V
8
V
CC
2 D
IN
1 CLK
µP
3 CS/LD
16-BIT
SHIFT
REG
AND
DAC
LATCH
16
16-BIT
DAC
REF
LTC1655: 2.048V
LTC1655L: 1.25V
6
REF
Functional Block Diagram: 16-Bit Rail-to-Rail DAC
1.0
0.8
0.6
DNL ERROR (LSB)
0.4
0.2
0
– 0.2
– 0.4
– 0.6
– 0.8
+
–
V
OUT
7
4 D
OUT
POWER-ON
RESET
GND
5
1655/55L TA01
TO
OTHER
DACS
– 1.0
0
16384
32768
CODE
49152
65535
U
Differential Nonlinearity
vs Input Code
1655/55L TA02
W
U
U
U
1
LTC1655/LTC1655L
ABSOLUTE
MAXIMUM
RATINGS
(Note 1)
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
TOP VIEW
CLK 1
D
IN
2
CS/LD 3
D
OUT
4
N8 PACKAGE
8-LEAD PDIP
8
7
6
5
V
CC
V
OUT
REF
GND
V
CC
to GND .............................................. – 0.5V to 7.5V
TTL Input Voltage .................................... – 0.5V to 7.5V
V
OUT
, REF
....................................... – 0.5V to V
CC
+ 0.5V
Maximum Junction Temperature ......................... 125°C
Operating Temperature Range
LTC1655C/LTC1655LC ........................... 0°C to 70°C
LTC1655I/LTC1655LI ........................ – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 125°C,
θ
JA
= 100°C/W (N8)
T
JMAX
= 125°C,
θ
JA
= 150°C/W (S8)
LTC1655CN8
LTC1655IN8
LTC1655CS8
LTC1655IS8
LTC1655LCN8
LTC1655LIN8
LTC1655LCS8
LTC1655LIS8
S8 PART MARKING
1655
1655I
1655L
1655LI
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
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 (LTC1655), V
CC
= 2.7V to 5.5V (LTC1655L); V
OUT
unloaded, REF unloaded, unless otherwise noted.
SYMBOL
DAC
Resolution
Monotonicity
DNL
Differential Nonlinearity
Guaranteed Monotonic (Note 2)
LTC1655, REF = 2.2V, V
CC
= 5V (Note 8) (External)
LTC1655L, REF = 2.2V, V
CC
= 5V (Note 8) (External)
LTC1655, REF = 2.2V, V
CC
= 5V (Note 8) (External)
LTC1655L, REF = 2.2V, V
CC
= 5V (Note 8) (External)
LTC1655
LTC1655L
q
q
q
q
q
q
q
q
PARAMETER
CONDITIONS
MIN
16
16
TYP
MAX
UNITS
Bits
Bits
±0.3
±0.5
±8
±8
0
0
±0.5
±0.5
±5
±5
0.5
±1.0
±1.0
±20
±20
3.0
3.5
±3.0
±3.5
±16
INL
ZSE
V
OS
Integral Nonlinearity
Zero Scale Error
Offset Error
Measured at Code 200
q
LTC1655, REF = 2.2V, V
CC
= 5V (Note 8) (External)
LTC1655L, REF = 1.3V, V
CC
= 2.7V (Note 8) (External)
q
REF = 2.2V (External), V
CC
= 5V (Note 8)
q
V
OS
TC
Offset Error Tempco
Gain Error
Gain Error Drift
µV/°C
LSB
ppm/°C
Power Supply
V
CC
Positive Supply Voltage
For Specified Performance
LTC1655
LTC1655L
(Note 3)
q
q
q
4.5
2.7
600
5.5
5.5
1200
I
CC
Supply Current
2
U
LSB
LSB
LSB
LSB
mV
mV
mV
mV
V
V
µA
W
U
U
W W
W
LTC1655/LTC1655L
ELECTRICAL CHARACTERISTICS
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 (LTC1655), V
CC
= 2.7V to 5.5V (LTC1655L); V
OUT
unloaded, REF unloaded, unless otherwise noted.
SYMBOL
PARAMETER
Short-Circuit Current Low
CONDITIONS
V
OUT
Shorted to GND
LTC1655
LTC1655L
V
OUT
Shorted to V
CC
LTC1655
LTC1655L
Input Code = 0
LTC1655
LTC1655L
Input Code = 65535, with Internal Reference
(Note 4)
(Note 4) to 0.0015% (16-Bit Settling Time), V
CC
= 5V
(Note 4) to 0.012% (13-Bit Settling Time), V
CC
= 5V
(Note 5)
DAC Switched Between 8000
H
and 7FFF
H
LTC1655, At 1kHz
LTC1655L, At 1kHz
LTC1655
LTC1655L
(Notes 6, 7) LTC1655
LTC1655L
LTC1655
LTC1655L
LTC1655, REF Overdriven to 2.2V
LTC1655L, REF Overdriven to 1.3V
q
q
q
q
q
q
MIN
TYP
MAX
UNITS
Op Amp DC Performance
q
q
q
q
q
q
70
70
80
70
40
70
120
140
140
150
120
160
±3
mA
mA
mA
mA
Ω
Ω
mV/V
V/µs
µs
µs
nV-s
nV-s
nV√Hz
nV√Hz
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
Spectral Density
Reference Output
Reference Output Voltage
Reference Input Range
Reference Output Tempco
Reference Input Resistance
Reference Short-Circuit Current
Reference Output Line Regulation
Reference Load Regulation
Reference Output Voltage Noise
Spectral Density
Digital I/O
V
IH
V
IL
V
OH
V
OL
Digital Input High Voltage
Digital Input Low Voltage
Digital Output High Voltage
Digital Output Low Voltage
±0.3
±0.7
20
10
0.3
12
280
220
2.036
1.240
2.2
1.3
2.048
1.250
2.060
1.260
V
CC
/2
V
CC
/2
V
V
V
V
ppm/°C
ppm/°C
kΩ
kΩ
5
10
8.5
7.0
13
13
40
100
±1.5
5
150
115
q
q
q
q
q
q
q
q
mA
mV/V
mV/A
nV√Hz
nV√Hz
V
V
I
OUT
= 100µA
LTC1655, At 1kHz
LTC1655L, At 1kHz
LTC1655
LTC1655L
LTC1655
LTC1655L
LTC1655, I
OUT
= – 1mA
LTC1655L, I
OUT
= – 1mA
LTC1655, I
OUT
= 1mA
LTC1655L, I
OUT
= 1mA
q
2.4
2.0
0.8
0.6
V
CC
– 1.0
V
CC
– 0.7
0.4
0.4
V
V
V
V
V
V
3
LTC1655/LTC1655L
ELECTRICAL CHARACTERISTICS
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 (LTC1655), V
CC
= 2.7V to 5.5V (LTC1655L); V
OUT
unloaded, REF unloaded, unless otherwise noted.
SYMBOL
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
LTC1655
LTC1655L
LTC1655
LTC1655L
LTC1655
LTC1655L
LTC1655
LTC1655L
LTC1655
LTC1655L
LTC1655
LTC1655L
LTC1655
LTC1655L
LTC1655, C
LOAD
= 15pF
LTC1655L, C
LOAD
= 15pF
LTC1655
LTC1655L
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
PARAMETER
Digital Input Leakage
Digital Input Capacitance
CONDITIONS
V
IN
= GND to V
CC
(Note 7)
q
MIN
TYP
MAX
±10
10
UNITS
µA
pF
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
40
60
0
0
40
60
40
60
50
80
40
60
20
30
20
20
20
30
120
300
ns
ns
ns
ns
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
Nonlinearity is defined from code 128 to code 65535 (full scale).
See Applications Information.
Note 3:
DAC switched between all 1s and all 0s. V
FS
= 4.096V.
Note 4:
Digital inputs at 0V or V
CC
.
Note 5:
Part is clocked with pin toggling between 1s and 0s, CS/LD is low.
Note 6:
Reference can be overdriven (see Applications Information).
Note 7:
Guaranteed by design. Not subject to test.
Note 8:
Guaranteed by correlation for other reference and supply
conditions.
4
LTC1655/LTC1655L
TYPICAL PERFORMANCE CHARACTERISTICS
V
CC
= 5V (LTC1655), V
CC
= 3V (LTC1655L) unless otherwise noted.
TC1655 Differential Nonlinearity
1.0
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
16,384
49,152
32,768
DIGITAL INPUT CODE
65,535
DIFFERENTIAL NONLINEARITY (LSB)
DIFFERENTIAL NONLINEARITY (LSB)
0.8
LTC1655 Integral Nonlinearity
10
8
INTEGRAL NONLINEARITY (LSB)
INTEGRAL NONLINEARITY (LSB)
6
4
2
0
–2
–4
–6
–8
–10
0
16,384
49,152
32,768
DIGITAL INPUT CODE
65,535
LTC1655 Minimum Supply
Headroom for Full Output Swing
vs Load Current
1.2
1.0
0.8
125°C
0.6
25°C
0.4
0.2
0
0
–55°C
∆V
OUT
< 1LSB
V
OUT
= 4.096V
CODE: ALL 1’s
V
CC
– V
OUT
(V)
V
CC
– V
OUT
(V)
10
5
LOAD CURRENT (mA)
U W
LTC1655L Differential Nonlinearity
1.0
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
16,384
49,152
32,768
DIGITAL INPUT CODE
65,535
1655/55L G01
1655/55L G01a
LTC1655L Integral Nonlinearity
10
8
6
4
2
0
–2
–4
–6
–8
–10
128
16,480
49,184
32,832
DIGITAL INPUT CODE
65,535
1655/55L G02
1655/55L G02a
LTC1655L Minimum Supply
Headroom for Full Output Swing
vs Load Current
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
–55°C
25°C
∆V
OUT
< 1LSB
V
OUT
= 2.5V
CODE: ALL 1’s
125°C
15
1655/55L G03
0
0
10
5
LOAD CURRENT (mA)
15
1655/55L G03a
5
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