FEATURES
LTC1655/LTC1655L
16-Bit Rail-to-Rail
Micropower DACs in
SO-8 Package
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DESCRIPTIO
■
16-Bit Monotonicity Over Temperature
■
Deglitched Rail-to-Rail Voltage Output
■
SO-8 Package
■
I
CC(TYP)
■
Internal Reference: 2.048V (LTC1655)
: 600µA
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
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APPLICATIO S
■
Digital Calibration
■
Industrial Process Control
■
Automatic Test Equipment
■
Cellular Telephones
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
MICROWIRETM 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
DAC family, allowing an easy
OUT
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.
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FU CTIO AL BLOCK DIAGRA
Functional Block Diagram: 16-Bit Rail-to-Rail DAC
µP
TO
OTHER
DACS
LTC1655: 4.5V TO 5.5V
LTC1655L: 2.7V TO 5.5V
V
2
D
IN
CLK1
16-BIT
SHIFT
OUT
REG
AND
DAC
LATCH
POWER-ON
RESET
CS/LD3
4
D
86
CC
16
LTC1655: 2.048V
LTC1655L: 1.25V
REF
16-BIT
DAC
REF
+
–
GND
5
V
OUT
1655/55L TA01
Differential Nonlinearity
vs Input Code
1.0
0.8
0.6
0.4
0.2
7
0
–0.2
DNL ERROR (LSB)
–0.4
–0.6
–0.8
–1.0
0
16384 32768
CODE
49152
65535
1655/55L TA02
1
LTC1655/LTC1655L
WW
W
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ABSOLUTE MAXIMUM RATINGS
(Note 1)
VCC to GND .............................................. – 0.5V to 7.5V
TTL Input Voltage .................................... – 0.5V to 7.5V
V
, REF ....................................... – 0.5V to V
OUT
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
+ 0.5V
CC
/
PACKAGE
CLK
1
D
2
IN
CS/LD
3
D
4
OUT
N8 PACKAGE
8-LEAD PDIP
T
= 125°C, θJA = 100°C/W (N8)
JMAX
T
= 125°C, θJA = 150°C/W (S8)
JMAX
Consult factory for Military grade parts.
O
TOP VIEW
8-LEAD PLASTIC SO
RDER I FOR ATIO
8
V
CC
V
7
OUT
REF
6
GND
5
S8 PACKAGE
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ORDER PART
NUMBER
LTC1655CN8
LTC1655IN8
LTC1655CS8
LTC1655IS8
LTC1655LCN8
LTC1655LIN8
LTC1655LCS8
LTC1655LIS8
S8 PART MARKING
1655
1655I
1655L
1655LI
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ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VCC = 4.5V to 5.5V (LTC1655), VCC = 2.7V to 5.5V (LTC1655L); V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
DAC
Resolution ● 16 Bits
Monotonicity ● 16 Bits
DNL Differential Nonlinearity Guaranteed Monotonic (Note 2)
LTC1655, REF = 2.2V, V
LTC1655L, REF = 2.2V, V
INL Integral Nonlinearity LTC1655, REF = 2.2V, V
LTC1655L, REF = 2.2V, V
ZSE Zero Scale Error LTC1655 ● 0 3.0 mV
LTC1655L
V
OS
V
OS
Power Supply
V
CC
I
CC
Offset Error Measured at Code 200
LTC1655, REF = 2.2V, V
LTC1655L, REF = 1.3V, V
TC Offset Error Tempco ±5 µV/°C
Gain Error REF = 2.2V (External), V
Gain Error Drift 0.5 ppm/°C
Positive Supply Voltage For Specified Performance
LTC1655
LTC1655L
Supply Current (Note 3) ● 600 1200 µA
unloaded, REF unloaded, unless otherwise noted.
OUT
= 5V (Note 8) (External) ● ±0.3 ±1.0 LSB
CC
= 5V (Note 8) (External) ● ±0.5 ±1.0 LSB
CC
= 5V (Note 8) (External) ● ±8 ±20 LSB
CC
= 5V (Note 8) (External) ● ±8 ±20 LSB
CC
● 0 3.5 mV
= 5V (Note 8) (External) ● ±0.5 ±3.0 mV
CC
= 2.7V (Note 8) (External) ● ±0.5 ±3.5 mV
CC
= 5V (Note 8) ● ±5 ±16 LSB
CC
● 4.5 5.5 V
● 2.7 5.5 V
2
LTC1655/LTC1655L
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VCC = 4.5V to 5.5V (LTC1655), VCC = 2.7V to 5.5V (LTC1655L); V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Op Amp DC Performance
Short-Circuit Current Low V
Short-Circuit Current High V
Output Impedance to GND Input Code = 0
Output Line Regulation Input Code = 65535, with Internal Reference ±3 mV/V
AC Performance
Voltage Output Slew Rate (Note 4) ● ±0.3 ±0.7 V/µs
Voltage Output Settling Time (Note 4) to 0.0015% (16-Bit Settling Time), V
Digital Feedthrough (Note 5) 0.3 nV-s
Midscale Glitch Impulse DAC Switched Between 8000H and 7FFF
Output Voltage Noise LTC1655, At 1kHz 280 nV√Hz
Spectral Density LTC1655L, At 1kHz 220 nV√Hz
Reference Output
Reference Output Voltage LTC1655 ● 2.036 2.048 2.060 V
Reference Input Range (Notes 6, 7) LTC1655 2.2 VCC/2 V
Reference Output Tempco LTC1655 5 ppm/°C
Reference Input Resistance LTC1655, REF Overdriven to 2.2V ● 8.5 13 kΩ
Reference Short-Circuit Current ● 40 100 mA
Reference Output Line Regulation ±1.5 mV/V
Reference Load Regulation I
Reference Output Voltage Noise LTC1655, At 1kHz 150 nV√Hz
Spectral Density LTC1655L, At 1kHz 115 nV√Hz
Digital I/O
V
IH
V
IL
V
OH
V
OL
Digital Input High Voltage LTC1655 ● 2.4 V
Digital Input Low Voltage LTC1655 ● 0.8 V
Digital Output High Voltage LTC1655, I
Digital Output Low Voltage LTC1655, I
Shorted to GND
OUT
LTC1655
LTC1655L
Shorted to V
OUT
LTC1655 ● 80 140 mA
LTC1655L
LTC1655
LTC1655L
(Note 4) to 0.012% (13-Bit Settling Time), V
LTC1655L
LTC1655L 1.3 V
LTC1655L 10 ppm/°C
LTC1655L, REF Overdriven to 1.3V
= 100µA ● 5 mV/A
OUT
LTC1655L
LTC1655L
LTC1655L, I
LTC1655L, I
CC
= –1mA ● VCC – 1.0 V
OUT
= – 1mA ● VCC – 0.7 V
OUT
= 1mA ● 0.4 V
OUT
= 1mA ● 0.4 V
OUT
unloaded, REF unloaded, unless otherwise noted.
OUT
● 70 120 mA
● 70 140 mA
● 70 150 mA
● 40 120 Ω
● 70 160 Ω
= 5V 20 µs
CC
= 5V 10 µs
CC
H
● 1.240 1.250 1.260 V
● 7.0 13 kΩ
● 2.0 V
● 0.6 V
12 nV-s
/2 V
CC
3
LTC1655/LTC1655L
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VCC = 4.5V to 5.5V (LTC1655), VCC = 2.7V to 5.5V (LTC1655L); V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
LEAK
C
IN
Switching
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
Digital Input Leakage VIN = GND to V
Digital Input Capacitance (Note 7) 10 pF
DIN Valid to CLK Setup LTC1655 ● 40 ns
LTC1655L
DIN Valid to CLK Hold LTC1655 ● 0ns
LTC1655L
CLK High Time LTC1655 ● 40 ns
LTC1655L
CLK Low Time LTC1655 ● 40 ns
LTC1655L
CS/LD Pulse Width LTC1655 ● 50 ns
LTC1655L
LSB CLK to CS/LD LTC1655 ● 40 ns
LTC1655L
CS/LD Low to CLK LTC1655 ● 20 ns
LTC1655L
D
Output Delay LTC1655, C
OUT
CLK Low to CS/LD Low LTC1655 ● 20 ns
LTC1655L, C
LTC1655L
CC
= 15pF ● 20 120 ns
LOAD
= 15pF ● 20 300 ns
LOAD
unloaded, REF unloaded, unless otherwise noted.
OUT
● ±10 µA
● 60 ns
● 0ns
● 60 ns
● 60 ns
● 80 ns
● 60 ns
● 30 ns
● 30 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
Note 4: Digital inputs at 0V or VCC.
= 4.096V.
FS
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
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TYPICAL PERFORMANCE CHARACTERISTICS
VCC = 5V (LTC1655), VCC = 3V (LTC1655L) unless otherwise noted.
LTC1655/LTC1655L
TC1655 Differential Nonlinearity
1.0
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
DIFFERENTIAL NONLINEARITY (LSB)
–0.8
–1.0
16,384
0
32,768
DIGITAL INPUT CODE
LTC1655 Integral Nonlinearity
10
8
6
4
2
0
–2
–4
–6
INTEGRAL NONLINEARITY (LSB)
–8
–10
16,384
0
32,768
DIGITAL INPUT CODE
49,152
49,152
1655/55L G01
65,535
1655/55L G02
65,535
LTC1655L Differential Nonlinearity
1.0
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
DIFFERENTIAL NONLINEARITY (LSB)
–0.8
–1.0
16,384
0
32,768
DIGITAL INPUT CODE
49,152
LTC1655L Integral Nonlinearity
10
8
6
4
2
0
–2
–4
–6
INTEGRAL NONLINEARITY (LSB)
–8
–10
128
16,480
32,832
DIGITAL INPUT CODE
49,184
65,535
1655/55L G01a
65,535
1655/55L G02a
LTC1655 Minimum Supply
Headroom for Full Output Swing
vs Load Current
1.2
∆V
< 1LSB
OUT
V
= 4.096V
OUT
1.0
CODE: ALL 1’s
0.8
(V)
OUT
– V
CC
V
0.6
0.4
0.2
0
0
125°C
25°C
5
LOAD CURRENT (mA)
LTC1655L Minimum Supply
Headroom for Full Output Swing
vs Load Current
2.0
∆V
< 1LSB
OUT
1.8
V
= 2.5V
OUT
CODE: ALL 1’s
1.6
1.4
(V)
1.2
OUT
1.0
– V
0.8
–55°C
10
15
1655/55L G03
CC
V
0.6
0.4
0.2
0
0
5
LOAD CURRENT (mA)
125°C
25°C
–55°C
10
15
1655/55L G03a
5