LTC2630
1
2630fg
For more information www.linear.com/LTC2630
Block Diagram
Features
applications
Description
Single 12-/10-/8-Bit
Rail-to- Rail DACs with 10ppm/°C
Reference in SC70
The LTC
®
2630 is a family of 12-, 10-, and 8-bit voltage-
output DACs with an integrated, high-accuracy, low-drift
reference in a 6-lead SC70 package. It has a rail-to-rail
output buffer and is guaranteed monotonic.
The LTC2630-L has a full-scale output of 2.5V, and
operates from a single 2.7V to 5.5V supply. The
LTC2630-H has a full-scale output of 4.096V, and oper-
ates from a 4.5V to 5.5V supply. Each DAC can also oper-
ate in supply as reference mode, which sets the full-scale
output to the supply voltage.
The parts use a simple SPI/MICROWIRE compatible
3-wire serial interface which operates at clock rates up
to 50MHz.
The LTC2630 incorporates a power-on reset circuit.
Options are available for reset to zero or reset to mid-
scale after power-up.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Analog
Devices, Inc. All other trademarks are the property of their respective owners. Protected by U.S.
Patents, including 5396245, 5859606, 6891433, 6937178 and 7414561.
Integral Nonlinearity (LTC2630A-LZ12)
n Integrated Precision Reference
2.5V Full Scale 10ppm/°C (LTC2630-L)
4.096V Full Scale 10ppm/°C (LTC2630-H)
n Maximum INL Error: 1 LSB (LTC2630A-12)
n Low Noise: 0.7mVP-P, 0.1Hz to 200kHz
n Guaranteed Monotonic over Temperature
n Selectable Internal Reference or Supply as Reference
n 2.7V to 5.5V Supply Range (LTC2630-L)
n Low Power Operation: 180µA at 3V
n Power Down to 1.8µA Maximum (C and I Grades)
n Power-on Reset to Zero or Mid-Scale Options
n SPI Serial Interface
n Double-Buffered Data Latches
n Tiny 6-Lead SC70 Package
n Mobile Communications
n Process Control and Industrial Automation
n Automatic Test Equipment
n Portable Equipment
n Automotive
DAC
REGISTER
RESISTOR
DIVIDER
INTERNAL
REFERENCE
INPUT
REGISTER
24-BIT
SHIFT
REGISTER
DAC VOUT
CONTROL
DECODE LOGIC
CS/LD
VCC
GND
DACREF
2630 BD
SCK
SDI
CODE
0
INL (LSB)
0
0.5
4095
2630 TA03
–0.5
–1.0 1024 2048 3072
1.0 VCC = 3V
VFS = 2.5V
LTC2630
2
2630fg
For more information www.linear.com/LTC2630
CS/LD 1
SCK 2
SDI 3
6 VOUT
5 GND
4 VCC
TOP VIEW
SC6 PACKAGE
6-LEAD PLASTIC SC70
TJMAX = 150°C (Note 5), θJA = 300°C/W
aBsolute maximum ratings
Supply Voltage (VCC) ...................................0.3V to 6V
CS/LD, SCK, SDI ..........................................0.3V to 6V
VOUT ..................................0.3V to min(VCC + 0.3V, 6V)
Operating Temperature Range
LTC2630C ................................................ 0°C to 70°C
LTC2630I .............................................40°C to 85°C
LTC2630H ..........................................40°C to 125°C
Maximum Junction Temperature .......................... 150°C
Storage Temperature Range ..................65°C to 150°C
Lead Temperature (Soldering, 10 sec) ...................300°C
(Notes 1, 2)
orDer inFormation
pin conFiguration
LTC2630 A C SC6 –L M 12 #TRM PBF
LEAD FREE DESIGNATOR
TAPE AND REEL
TR = 2,500-Piece Tape and Reel
TRM = 500-Piece Tape and Reel
RESOLUTION
12 = 12-Bit
10 = 10-Bit
8 = 8-Bit
POWER-ON RESET
M = Reset to Mid-Scale
Z = Reset to Zero-Scale
FULL-SCALE VOLTAGE, INTERNAL REFERENCE MODE
L = 2.5V
H = 4.096V
PACKAGE TYPE
SC6 = 6-Lead SC70
TEMPERATURE GRADE
C = Commercial Temperature Range (0°C to 70°C)
I = Industrial Temperature Range (–40°C to 85°C)
H = Automotive Temperature Range (–40°C to 125°C)
ELECTRICAL GRADE (OPTIONAL)
A = ±1 LSB Maximum INL (12-Bit)
PRODUCT PART NUMBER
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
http://www.linear.com/product/LTC2630#orderinfo
LTC2630
3
2630fg
For more information www.linear.com/LTC2630
proDuct selection guiDe
PART NUMBER PART MARKING* VFS WITH INTERNAL REFERENCE POWER-ON RESET TO CODE RESOLUTION VCC MAXIMUM INL
LTC2630A-LM12
LTC2630A-LZ12
LTC2630A-HM12
LTC2630A-HZ12
LCZB
LCSB
LCWR
LCZC
2.5V (4095/4096)
2.5V (4095/4096)
4.096V (4095/4096)
4.096V (4095/4096)
Mid-Scale
Zero
Mid-Scale
Zero
12-Bit
12-Bit
12-Bit
12-Bit
2.7V–5.5V
2.7V–5.5V
4.5V–5.5V
4.5V–5.5V
±1LSB
±1LSB
±1LSB
±1LSB
LTC2630-LM12
LTC2630-LM10
LTC2630-LM8
LCZB
LCZF
LCYW
2.5V (4095/4096)
2.5V (1023/1024)
2.5V (255/256)
Mid-Scale
Mid-Scale
Mid-Scale
12-Bit
10-Bit
8-Bit
2.7V–5.5V
2.7V–5.5V
2.7V–5.5V
±2LSB
±1LSB
±0.5LSB
LTC2630-LZ12
LTC2630-LZ10
LTC2630-LZ8
LCSB
LCZD
LCYV
2.5V (4095/4096)
2.5V (1023/1024)
2.5V (255/256)
Zero
Zero
Zero
12-Bit
10-Bit
8-Bit
2.7V–5.5V
2.7V–5.5V
2.7V–5.5V
±2LSB
±1LSB
±0.5LSB
LTC2630-HM12
LTC2630-HM10
LTC2630-HM8
LCWR
LCZH
LCYY
4.096V (4095/4096)
4.096V (1023/1024)
4.096V (255/256)
Mid-Scale
Mid-Scale
Mid-Scale
12-Bit
10-Bit
8-Bit
4.5V–5.5V
4.5V–5.5V
4.5V–5.5V
±2LSB
±1LSB
±0.5LSB
LTC2630-HZ12
LTC2630-HZ10
LTC2630-HZ8
LCZC
LCZG
LCYX
4.096V (4095/4096)
4.096V (1023/1024)
4.096V (255/256)
Zero
Zero
Zero
12-Bit
10-Bit
8-Bit
4.5V–5.5V
4.5V–5.5V
4.5V–5.5V
±2LSB
±1LSB
±0.5LSB
*The temperature grade is identified by a label on the shipping container.
LTC2630
4
2630fg
For more information www.linear.com/LTC2630
electrical characteristics
SYMBOL
PARAMETER CONDITIONS
LTC2630-8 LTC2630-10 LTC2630-12 LTC2630A-12
UNITS
MIN TYP MAX
MIN
TYP MAX MIN TYP MAX MIN TYP MAX
DC Performance
Resolution l8 10 12 12 Bits
Monotonicity VCC = 3V, Internal Ref. (Note 3) l8 10 12 12 Bits
DNL Differential
Nonlinearity
VCC = 3V, Internal Ref. (Note 3) l±0.5 ±0.5 ±1 ±1 LSB
INL Integral Nonlinearity VCC = 3V, Internal Ref. (Note 3) l±0.05 ±0.5 ±0.2 ±1 ±1 ±2 ±0.5 ±1 LSB
ZSE Zero Scale Error VCC = 3V, Internal Ref., Code = 0 l0.5 5 0.5 5 0.5 5 0.5 5 mV
VOS Offset Error VCC = 3V, Internal Ref. (Note 4) l±0.5 ±5 ±0.5 ±5 ±0.5 ±5 ±0.5 ±5 mV
VOSTC VOS Temperature
Coefficient
VCC = 3V, Internal Ref. (Note 4) ±10 ±10 ±10 ±10 µV/°C
FSE Full Scale Error VCC = 3V, Internal Ref. l±0.2 ±0.8 ±0.2 ±0.8 ±0.2 ±0.8 ±0.2 ±0.8 %FSR
VFSTC Full Scale Voltage
Temperature
Coefficient
VCC = 3V, Internal Ref. (Note 9)
C-Grade
I-Grade
H-Grade
±10
±10
±10
±10
±10
±10
±10
±10
±10
±10
±10
±10
ppm/°C
ppm/°C
ppm/°C
Load Regulation Internal Ref., Mid-Scale,
VCC = 3V ±10%, 5mA IOUT5mA
VCC = 5V ±10%, 10mA IOUT 10mA
l
l
0.008
0.008
0.016
0.016
0.03
0.03
0.064
0.064
0.13
0.13
0.256
0.256
0.13
0.13
0.256
0.256
LSB/mA
LSB/mA
ROUT DC Output
Impedance
Internal Ref., Mid-Scale,
VCC = 3V ±10%, 5mA IOUT 5mA
VCC = 5V ±10%, 10mA IOUT 10mA
l
l
0.08
0.08
0.156
0.156
0.08
0.08
0.156
0.156
0.08
0.08
0.156
0.156
0.08
0.08
0.156
0.156
Ω
Ω
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 2.7V to 5.5V, VOUT unloaded unless otherwise specified.
LTC2630-LM12/-LM10/-LM8/-LZ12/-LZ10/-LZ8, LTC2630A-LM12/-LZ12 (VFS = 2.5V)
SYMBOL
PARAMETER CONDITIONS MIN TYP MAX UNITS
VOUT DAC Output Span Supply as Reference
Internal Reference
0V to VCC
0V to 2.5
V
V
PSR Power Supply Rejection VCC = 3V ±10% or 5V ±10% 80 dB
ISC Short Circuit Output Current (Note 5)
Sinking
Sourcing
VFS = VCC = 5.5V
Zero Scale; VOUT Shorted to VCC
Full Scale; VOUT Shorted to GND
l
l
27
28
50
50
mA
mA
Power Supply
VCC Power Supply Voltage For Specified Performance l2.7 5.5 V
ICC Supply Current (Note 6) VCC = 3V, Supply as Reference
VCC = 3V, Internal Reference
VCC = 5V, Supply as Reference
VCC = 5V, Internal Reference
l
l
l
l
160
180
180
190
220
240
250
260
µA
µA
µA
µA
ISD Supply Current in Power-Down Mode
(Note 6)
VCC = 5V, C-Grade, I-Grade
VCC = 5V, H-Grade
l
l
0.36
0.36
1.8
5
µA
µA
Digital I/O
VIH Digital Input High Voltage VCC = 3.6V to 5.5V
VCC = 2.7V to 3.6V
l
l
2.4
2.0
V
V
VIL Digital Input Low Voltage VCC = 4.5V to 5.5V
VCC = 2.7V to 4.5V
l
l
0.8
0.6
V
V
ILK Digital Input Leakage VIN = GND to VCC l±1 µA
CIN Digital Input Capacitance (Note 7) l2.5 pF
LTC2630
5
2630fg
For more information www.linear.com/LTC2630
electrical characteristics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 2.7V to 5.5V, VOUT unloaded unless otherwise specified.
LTC2630-LM12/-LM10/-LM8/-LZ12/-LZ10/-LZ8, LTC2630A-LM12/-LZ12 (VFS = 2.5V)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
AC Performance
tSSettling Time VCC = 3V (Note 8)
±0.39% (±1LSB at 8 Bits)
±0.098% (±1LSB at 10 Bits)
±0.024% (±1LSB at 12 Bits)
3.2
3.9
4.4
µs
µs
µs
Voltage Output Slew Rate 1.0 V/µs
Capacitive Load Driving 500 pF
Glitch Impulse At Mid-Scale Transition 2 nVs
enOutput Voltage Noise Density At f = 1kHz, Supply as Reference
At f = 10kHz, Supply as Reference
At f = 1kHz, Internal Reference
At f = 10kHz, Internal Reference
140
130
160
150
nV/Hz
nV/Hz
nV/Hz
nV/Hz
Output Voltage Noise 0.1Hz to 10Hz, Supply as Reference
0.1Hz to 10Hz, Internal Reference
0.1Hz to 200kHz, Supply as Reference
0.1Hz to 200kHz, Internal Reference
20
20
650
700
µVP-P
µVP-P
µVP-P
µVP-P
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t1SDI Valid to SCK Setup l4 ns
t2SDI Valid to SCK Hold l4 ns
t3SCK High Time l9 ns
t4SCK Low Time l9 ns
t5CS/LD Pulse width l10 ns
t6SCK High to CS/LD High l7 ns
t7CS/LD Low to SCK High l7 ns
t10 CS/LD High to SCK Positive Edge l7 ns
SCK Frequency 50% Duty Cycle l50 MHz
timing characteristics
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. VCC = 2.7V to 5.5V. (See Figure 1) (Note 7).
LTC2630-LM12/-LM10/-LM8/-LZ12/-LZ10/-LZ8, LTC2630A-LM12/-LZ12 (VFS = 2.5V)
LTC2630
6
2630fg
For more information www.linear.com/LTC2630
electrical characteristics
SYMBOL PARAMETER CONDITIONS
LTC2630-8 LTC2630-10 LTC2630-12 LTC2630A-12
UNITS
MIN TYP MAX MIN TYP MAX MIN TYP MAX MIN TYP MAX
DC Performance
Resolution l8 10 12 12 Bits
Monotonicity VCC = 5V, Internal Ref. (Note 3) l8 10 12 12 Bits
DNL Differential
Nonlinearity
VCC = 5V, Internal Ref. (Note 3) l±0.5 ±0.5 ±1 ±1 LSB
INL Integral
Nonlinearity
VCC = 5V, Internal Ref. (Note 3) l±0.05 ±0.5 ±0.2 ±1 ±1 ±2 ±0.5 ±1 LSB
ZSE Zero Scale Error VCC = 5V, Internal Ref., Code = 0 l0.5 5 0.5 5 0.5 5 0.5 5 mV
VOS Offset Error VCC = 5V, Internal Ref. (Note 4) l±0.5 ±5 ±0.5 ±5 ±0.5 ±5 ±0.5 ±5 mV
VOSTC VOS Temperature
Coefficient
VCC = 5V, Internal Ref. (Note 4) ±10 ±10 ±10 ±10 µV/°C
FSE Full Scale Error VCC = 5V, Internal Ref. l±0.2 ±0.8 ±0.2 ±0.8 ±0.2 ±0.8 ±0.2 ±0.8 %FSR
VFSTC Full Scale Voltage
Temperature
Coefficient
VCC = 5V, Internal Ref. (Note 9)
C-Grade
I-Grade
H-Grade
±10
±10
±10
±10
±10
±10
±10
±10
±10
±10
±10
±10
ppm/°C
ppm/°C
ppm/°C
Load Regulation VCC = 5V ±10%, Internal Ref.,
Mid-Scale, –10mA ≤ IOUT ≤ 10mA
l0.006 0.01
0.025
0.04 0.10 0.16 0.10 0.16 LSB/
mA
ROUT DC Output
Impedance
VCC = 5V ±10%, Internal Ref.,
Mid-Scale, –10mA ≤ IOUT ≤ 10mA
l0.1
0.156
0.1
0.156
0.1 0.156 0.1 0.156 Ω
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 4.5V to 5.5V, VOUT unloaded unless otherwise specified.
LTC2630-HM12/-HM10/-HM8/-HZ12/-HZ10/-HZ8, LTC2630A-HM12/-HZ12 (VFS = 4.096V)
SYMBOL
PARAMETER CONDITIONS MIN TYP MAX UNITS
VOUT DAC Output Span Supply as Reference
Internal Reference
0V to VCC
0V to 4.096
V
V
PSR Power Supply Rejection VCC = 5V ±10% –80 dB
ISC Short Circuit Output Current (Note 5)
Sinking
Sourcing
VFS = VCC = 5.5V
Zero Scale; VOUT Shorted to VCC
Full Scale; VOUT Shorted to GND
l
l
27
–28
50
–50
mA
mA
Power Supply
VCC Power Supply Voltage For Specified Performance l4.5 5.5 V
ICC Supply Current (Note 6) VCC = 5V, Supply as Reference
VCC = 5V, Internal Reference
l
l
180
200
260
280
µA
µA
ISD Supply Current in Power-Down Mode
(Note 6)
VCC = 5V, C-Grade, I-Grade
VCC = 5V, H-Grade
l
l
0.36
0.36
1.8
5
µA
µA
Digital I/O
VIH Digital Input High Voltage l2.4 V
VIL Digital Input Low Voltage l0.8 V
ILK Digital Input Leakage VIN = GND to VCC l±1 µA
CIN Digital Input Capacitance (Note 7) l2.5 pF
LTC2630
7
2630fg
For more information www.linear.com/LTC2630
electrical characteristics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 4.5V to 5.5V, VOUT unloaded unless otherwise specified.
LTC2630-HM12/-HM10/-HM8/-HZ12/-HZ10/-HZ8, LTC2630A-HM12/-HZ12 (VFS = 4.096V)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
AC Performance
tSSettling Time VCC = 5V (Note 8)
±0.39% (±1LSB at 8 Bits)
±0.098% (±1LSB at 10 Bits)
±0.024% (±1LSB at 12 Bits)
3.7
4.4
4.8
µs
µs
µs
Voltage Output Slew Rate 1.0 V/µs
Capacitive Load Driving 500 pF
Glitch Impulse At Mid-Scale Transition 2.4 nVs
enOutput Voltage Noise Density At f = 1kHz, Supply as Reference
At f = 10kHz, Supply as Reference
At f = 1kHz, Internal Reference
At f = 10kHz, Internal Reference
140
130
210
200
nV/Hz
nV/Hz
nV/Hz
nV/Hz
Output Voltage Noise 0.1Hz to 10Hz, Supply as Reference
0.1Hz to 10Hz, Internal Reference
0.1Hz to 200kHz, Supply as Reference
0.1Hz to 200kHz, Internal Reference
20
20
650
750
µVP-P
µVP-P
µVP-P
µVP-P
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: All voltages are with respect to GND.
Note 3: Linearity and monotonicity are defined from code kL to code 2N–1,
where N is the resolution and kL is given by kL = 0.016 (2N/ VFS), rounded
to the nearest whole code. For VFS = 2.5V and N = 12, kL = 26 and linearity
is defined from code 26 to code 4,095. For VFS = 4.096V and
N = 12, kL = 16 and linearity is defined from code 16 to code 4,095.
Note 4: Inferred from measurement at code 16 (LTC2630-12), code 4
(LTC2630-10) or code 1 (LTC2630-8).
Note 5: This IC includes current limiting that is intended to protect the
device during momentary overload conditions. Junction temperature can
exceed the rated maximum during current limiting. Continuous operation
above the specified maximum operating junction temperature may impair
device reliability.
Note 6: Digital inputs at 0V or VCC.
Note 7: Guaranteed by design and not production tested.
Note 8: Internal Reference mode. DAC is stepped 1/4 scale to 3/4 scale
and 3/4 scale to 1/4 scale. Load is 2kW in parallel with 100pF to GND.
Note 9: Temperature coefficient is calculated by dividing the maximum
change in output voltage by the specified temperature range.
timing characteristics
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. VCC = 4.5V to 5.5V. (See Figure 1) (Note 7).
LTC2630-HM12/-HM10/-HM8/-HZ12/-HZ10/-HZ8, LTC2630A-HM12/-HZ12 (VFS = 4.096V)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t1SDI Valid to SCK Setup l4 ns
t2SDI Valid to SCK Hold l4 ns
t3SCK High Time l9 ns
t4SCK Low Time l9 ns
t5CS/LD Pulse width l10 ns
t6SCK High to CS/LD High l7 ns
t7CS/LD Low to SCK High l7 ns
t10 CS/LD High to SCK Positive Edge l7 ns
SCK Frequency 50% Duty Cycle l50 MHz
LTC2630
8
2630fg
For more information www.linear.com/LTC2630
typical perFormance characteristics
INL vs Temperature
DNL vs Temperature
Full-Scale Output Voltage
vs Temperature
LTC2630-LM12/-LZ12 (VFS = 2.5V)
Integral Nonlinearity (INL)
CODE
0
INL (LSB)
0
0.5
4095
2630 G01
–0.5
–1.0 1024 2048 3072
1.0 VCC = 3V
Differential Nonlinearity (DNL)
CODE
0
DNL (LSB)
0
0.5
4095
2630 G02
–0.5
–1.0 1024
VCC = 3V
2048 3072
1.0
TEMPERATURE (°C)
–50 –25 25 75 125
INL (LSB)
0
0.5
150
2630 G03
–0.5
–1.0 050 100
1.0
VCC = 3V
INL (POS)
INL (NEG)
TEMPERATURE (°C)
–50 –25 25 75 125
DNL (LSB)
0
0.5
150
2630 G04
–0.5
–1.0 050 100
1.0
VCC = 3V
DNL (POS)
DNL (NEG)
TEMPERATURE (°C)
–50 –25 25 75 125
FS OUTPUT VOLTAGE (V)
2.50
2.51
150
2630 G05
2.49
2.48 050 100
2.52
VCC = 3V
2µs/DIV
2630 G06
VOUT
1LSB/DIV
1/4 SCALE TO 3/4 SCALE STEP
VCC = 3V, VFS = 2.5V
RL = 2k, CL = 100pF
AVERAGE OF 256 EVENTS
CS/LD
2V/DIV
3.6µs
Settling to ±1LSB Settling to ±1LSB
2µs/DIV
2630 G07
VOUT
1LSB/DIV
3/4 SCALE TO 1/4 SCALE STEP
VCC = 3V, VFS = 2.5V
RL = 2k, CL = 100pF
AVERAGE OF 256 EVENTS
CS/LD
2V/DIV
4.4µs
LTC2630
9
2630fg
For more information www.linear.com/LTC2630
TEMPERATURE (°C)
–50 –25 25 75 125
FS OUTPUT VOLTAGE (V)
4.095
4.105
150
2630 G12
4.085
4.075 050 100
4.115
VCC = 5V
2µs/DIV
2630 G13
VOUT
1LSB/DIV
1/4 SCALE TO 3/4 SCALE STEP
VCC = 5V, VFS = 4.096V
RL = 2k, CL = 100pF
AVERAGE OF 256 EVENTS
CS/LD
2V/DIV
4.0µs
Settling to ±1LSB
2µs/DIV
2630 G14
VOUT
1LSB/DIV
CS/LD
2V/DIV
4.8µs
1/4 SCALE TO 3/4 SCALE STEP
VCC = 5V, VFS = 4.096V
RL = 2k, CL = 100pF
AVERAGE OF 256 EVENTS
Settling to ±1LSB
typical perFormance characteristics
INL vs Temperature
DNL vs Temperature
Full-Scale Output Voltage
vs Temperature
LTC2630-HM12/-HZ12 (VFS = 4.096V)
Integral Nonlinearity (INL)
Differential Nonlinearity (DNL)
CODE
0
DNL (LSB)
0
0.5
4095
2630 G09
–0.5
–1.0 1024 2048 3072
1.0 VCC = 5V
CODE
0
INL (LSB)
0
0.5
4095
2630 G08
–0.5
–1.0 1024 2048 3072
1.0 VCC = 5V
TEMPERATURE (°C)
–50 –25 25 75 125
INL (LSB)
0
0.5
150
2630 G10
–0.5
–1.0 050 100
1.0
VCC = 5V
INL (POS)
INL (NEG)
TEMPERATURE (°C)
–50 –25 25 75 125
DNL (LSB)
0
0.5
150
2630 G11
–0.5
–1.0 050 100
1.0
VCC = 5V
DNL (POS)
DNL (NEG)
LTC2630
10
2630fg
For more information www.linear.com/LTC2630
TEMPERATURE (°C)
–50 –25 0 25 50 75 100 125 150
OFFSET ERROR (mV)
0
1
2
2630 G21
–1
–2
–3
3
IOUT (mA)
–30 –20 –10 0 10 20 30
ΔVOUT (mV)
0
2
4
6
8
2630 G19
–6
–4
–2
–8
–10
10
INTERNAL REF.
CODE = MIDSCALE
VCC = 5V (LTC2630-H)
VCC = 5V (LTC2630-L)
VCC = 3V (LTC2630-L)
typical perFormance characteristics
LTC2630-10
LTC2630-8
LTC2630
Integral Nonlinearity (INL)
Differential Nonlinearity (DNL)
Integral Nonlinearity (INL)
CODE
0
INL (LSB)
0
0.5
255
2630 G17
–0.5
–1.0 64 128 192
1.0
VCC = 3V
VFS = 2.5V
CODE
0
DNL (LSB)
0
0.5
1023
2630 G16
–0.5
–1.0 256 512 768
1.0 VCC = 5V
VFS = 4.096V
Differential Nonlinearity (DNL)
CODE
0
DNL (LSB)
0
0.25
255
2630 G18
–0.25
–0.50 64 128 192
0.50
VCC = 3V
VFS = 2.5V
CODE
0
INL (LSB)
0
0.5
1023
2630 G15
–0.5
–1.0 256 512 768
1.0 VCC = 5V
VFS = 4.096V
IOUT (mA)
–30 –20 –10 0 10 20 30
V
OUT
(V)
–0.05
0
0.05
0.10
0.15
2630 G20
–0.20
–0.15
–0.10
0.20
INTERNAL REF.
CODE = MIDSCALE
VCC = 5V (LTC2630-H)
VCC = 5V (LTC2630-L)
VCC = 3V (LTC2630-L)
Offset Error vs Temperature
Current Limiting
Load Regulation
LTC2630
11
2630fg
For more information www.linear.com/LTC2630
2µs/DIV
0.5V/DIV
2630 G22
VFS = VCC = 5V
1/4 SCALE TO 3/4 SCALE
typical perFormance characteristics
LTC2630
Large-Signal Response
IOUT (mA)
0 1 2 3 4 5 6 7 8 9 10
VOUT (V)
2.5
2.0
3.5
3.0
4.0
2630 G25
1.5
1.0
0.5
0
5.0
4.5 5V SOURCING
3V (LTC2630-L) SOURCING
3V (LTC2630-L) SINKING
5V SINKING
Headroom at Rails
vs Output Current
0.1Hz to 10Hz Voltage Noise
LOGIC VOLTAGE (V)
0 1 2 3 4 5
ICC (mA)
0.4
0.6
0.8
2630 G29
0.2
0
1.0
VCC = 5V
VCC = 3V
(LTC2630-L)
SWEEP SCK, SDI, CS/LD
BETWEEN 0V AND VCC
Supply Current vs Logic Voltage
1s/DIV
10µV/DIV
2630 G27
VCC = 4V, VFS = 2.5V
CODE = MIDSCALE
Noise Voltage vs Frequency
2µs/DIV
LTC2630-H12, VCC = 5V:
2.4nV-s TYP
LTC2630-L12, VCC = 3V:
2.0nV-s TYP
VOUT
5mV/DIV
2630 G23
CS/LD
5V/DIV
INTERNAL REF
Mid-Scale-Glitch Impulse
Power-On Reset Glitch
200µs/DIV
VCC
2V/DIV
2630 G24
LTC2630-L
VOUT
2mV/DIV
ZERO-SCALE
FREQUENCY (Hz)
100
NOISE VOLTAGE (nV/Hz)
200
300
1M
2630 G26
100
01k 10k 100k
500
400
CODE = MIDSCALE
LTC2630-H
(VCC = 5V)
LTC2630-L
(VCC = 4V)
Exiting Power-Down to Mid-Scale
4µs/DIV
2630 G28
LTC2630-H
CS/LD
2V/DIV
VOUT
0.5V/DIV
LTC2630
12
2630fg
For more information www.linear.com/LTC2630
Block Diagram
pin Functions
CS/LD (Pin 1): Serial Interface Chip Select/Load Input.
When CS/LD is low, SCK is enabled for shifting data on
SDI into the register. When CS/LD is taken high, SCK
is disabled and the specified command (see Table 1) is
executed.
SCK (Pin 2): Serial Interface Clock Input. CMOS and TTL
compatible.
SDI (Pin 3): Serial Interface Data Input. Data on SDI
is clocked into the DAC on the rising edge of SCK. The
LTC2630 accepts input word lengths of either 24 or 32
bits.
VCC (Pin 4): Supply Voltage Input. 2.7V VCC 5.5V
(LTC2630-L) or 4.5V V
CC
5.5V (LTC2630-H). Also
used as the reference input when the part is programmed
to operate in supply as reference mode. Bypass to GND
with a 0.1µF capacitor.
GND (Pin 5): Ground.
VOUT (Pin 6): DAC Analog Voltage Output.
DAC
REGISTER
RESISTOR
DIVIDER
INTERNAL
REFERENCE
INPUT
REGISTER
24-BIT
SHIFT
REGISTER
DAC VOUT
CONTROL
DECODE LOGIC
CS/LD
VCC
GND
DACREF
2630 BD
SCK
SDI
LTC2630
13
2630fg
For more information www.linear.com/LTC2630
timing Diagram
The LTC2630 is a family of single voltage output DACs in
6-lead SC70 packages. Each DAC can operate rail-to-rail
referenced to the input supply, or with its full-scale voltage
set by an integrated reference. Twelve combinations of
accuracy (12-, 10-, and 8-bit), power-on reset value (zero
or mid-scale), and full-scale voltage (2.5V or 4.096V) are
available. The LTC2630 is controlled using a 3-wire SPI/
MICROWIRE compatible interface.
Power-On Reset
The LTC2630-HZ/-LZ clear the output to zero scale when
power is first applied, making system initialization con-
sistent and repeatable.
For some applications, downstream circuits are active
during DAC power-up, and may be sensitive to nonzero
outputs from the DAC during this time. The LTC2630 con-
tains circuitry to reduce the power-on glitch: the analog
output typically rises less than 5mV above zero scale dur-
ing power on if the power supply is ramped to 5V in 1ms
or more. In general, the glitch amplitude decreases as
the power supply ramp time is increased. See “Power-On
Reset Glitch” in the Typical Performance Characteristics
section.
The LTC2630-HM/-LM provide an alternative reset, set-
ting the output to mid-scale when power is first applied.
SDI
CS/LD
SCK
t2
t10
t5t7
t6
t1
t3t4
1 2 3 23 24
2630 F01
operation
Transfer Function
The digital-to-analog transfer function is
VOUT(IDEAL) =k
N
VREF
where k is the decimal equivalent of the binary DAC
input code, N is the resolution, and V
REF
is either 2.5V
(LTC2630-L) or 4.096V (LTC2630-H) in internal ref-
erence mode, and VCC in Supply as reference mode.
Table 1. Command Codes
Command*
C3 C2 C1 C0
0 0 0 0 Write to Input Register
0 0 0 1 Update (Power up) DAC Register
0 0 1 1 Write to and Update (Power up) DAC Register
0 1 0 0 Power down
0 1 1 0 Select Internal Reference (Power-on Reset Default)
0 1 1 1 Select Supply as Reference (VREF = VCC)
*Command codes not shown are reserved and should not be used.
Figure 1. Serial Interface Timing
LTC2630
14
2630fg
For more information www.linear.com/LTC2630
Serial Interface
The CS/LD input is level triggered. When this input is
taken low, it acts as a chip-select signal, enabling the SDI
and SCK buffers and the input shift register. Data (SDI
input) is transferred at the next 24 rising SCK edges. The
4-bit command, C3-C0, is loaded first; then 4 don’t-care
bits; and finally the 16-bit data word. The data word com-
prises the 12-, 10- or 8-bit input code, ordered MSB-to-
LSB, followed by 4, 6 or 8 don’t-care bits (LTC2630-12,
-10 and -8 respectively; see Figure 2). Data can only be
transferred to the device when the CS/LD signal is low,
beginning on the first rising edge of SCK. SCK may be
high or low at the falling edge of CS/LD. The rising edge
of CS/LD ends the data transfer and causes the device
to execute the command specified in the 24-bit input
sequence. The complete sequence is shown in Figure 3a.
operation
The command (C3-C0) assignments are shown in Table 1.
The first three commands in the table consist of write and
update operations. A Write operation loads a 16-bit data
word from the 24-bit shift register into the input register.
In an Update operation, the input register is copied to
the DAC register and converted to an analog voltage at
the DAC output. Write to and Update combines the first
two commands. The Update operation also powers up the
DAC if it had been in power-down mode. The data path
and registers are shown in the Block Diagram.
While the minimum input sequence is 24-bits, it may
optionally be extended to 32-bits to accommodate micro-
processors that have a minimum word width of 16-bits
(2 bytes). To use the 32-bit width, 8 don’t-care bits are
transferred to the device first, followed by the 24-bit
sequence described. Figure 3b shows the 32-bit sequence.
The 16-bit data word is ignored for all commands that do
not include a Write operation.
2630 F02
C3
COMMAND 4 DON'T-CARE BITS
MSB
MSB
MSB
LSB
LSB
LSB
DATA (12 BITS + 4 DON'T-CARE BITS)
C2 C1 C0 X X X X D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X
C3
COMMAND 4 DON'T-CARE BITS DATA (10 BITS + 6 DON'T-CARE BITS)
C2 C1 C0 X X X X D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X X X
C3
COMMAND
INPUT WORD (LTC2630-12)
INPUT WORD (LTC2630-10)
INPUT WORD (LTC2630-8)
4 DON'T-CARE BITS DATA (8 BITS + 8 DON'T-CARE BITS)
C2 C1 C0 X X X X D7 D6 D5 D4 D3 D2 D1 D0 X X X X X X X X
Figure 2. Command and Data Input Format
LTC2630
15
2630fg
For more information www.linear.com/LTC2630
operation
12345678910 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
C2 C1 C0 X X X X D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X XC3XXXXXXXX
CS/LD
SCK
SDI
COMMAND WORD DATA WORD
8 DON’T-CARE BITS 4 DON’T-CARE BITS
2630 F03b
32-BIT INPUT WORD
Figure 3b. 32-Bit Load Sequence
LTC2630-12 SDI Data Word: 12-Bit Input Code + 4 Don’t-Care Bits (Shown);
LTC2630-10 SDI Data Word: 10-Bit Input Code + 6 Don’t-Care Bits;
LTC2630-8 SDI Data Word: 8-Bit Input Code + 8 Don’t-Care Bits
12345678910 11 12 13 14 15 16 17 18 19 20 21 22 23 24
C2 C1 C0 X X X X D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X XC3
CS/LD
SCK
SDI
COMMAND WORD 4 DON’T-CARE BITS DATA WORD
24-BIT INPUT WORD
2630 F03a
Figure 3a. 24-Bit Load Sequence (Minimum Input Word)
LTC2630-12 SDI Data Word: 12-Bit Input Code + 4 Don’t-Care Bits (Shown);
LTC2630-10 SDI Data Word: 10-Bit Input Code + 6 Don’t-Care Bits;
LTC2630-8 SDI Data Word: 8-Bit Input Code + 8 Don’t-Care Bits
LTC2630
16
2630fg
For more information www.linear.com/LTC2630
operation
Power-Down Mode
For power-constrained applications, power-down mode
can be used to reduce the supply current whenever the
DAC output is not needed. When in power-down, the buf-
fer amplifier, bias circuit, and reference circuit are dis-
abled and draw essentially zero current. The DAC output
is put into a high-impedance state, and the output pin
is passively pulled to ground through a 200kΩ resistor.
Input and DAC register contents are not disturbed during
power-down.
The DAC can be put into power-down mode by using
command 0100. The supply current is reduced to 1.8µA
maximum when the DAC is powered down.
Normal operation resumes after executing any command
that includes a DAC update, as shown in Table 1. The DAC
is powered up and its voltage output is updated. Normal
settling is delayed while the bias, reference, and amplifier
circuits are re-enabled. The power-up delay time is 18µs
for settling to 12-bits.
Reference Modes
For applications where an accurate external reference is
not available, the LTC2630 has a user-selectable, inte-
grated reference. The LTC2630-LM and LTC2630-LZ pro-
vide a full-scale output of 2.5V. The LTC2630-HM and
LTC2630-HZ provide a full-scale output of 4.096V.
The internal reference can be useful in applications where
the supply voltage is poorly regulated. Internal Reference
mode can be selected by using command 0110, and is
the power-on default.
The DAC can also operate in supply as reference mode
using command 0111. In this mode, V
CC
supplies the
DACs reference voltage and the supply current is reduced.
Voltage Output
The LTC2630’s integrated rail-to-rail amplifier has guar-
anteed load regulation when sourcing or sinking up to
10mA at 5V, and 5mA at 3V.
Load regulation is a measure of the amplifier’s ability to
maintain the rated voltage accuracy over a wide range of
load current. The measured change in output voltage per
change in forced load current is expressed in LSB/mA.
DC output impedance is equivalent to load regulation, and
may be derived from it by simply calculating a change in
units from LSB/mA to ohms. The amplifier’s DC output
impedance is 0.1Ω when driving a load well away from
the rails.
When drawing a load current from either rail, the output
voltage headroom with respect to that rail is limited by
the 50Ω typical channel resistance of the output devices
(e.g., when sinking 1mA, the minimum output voltage
is 50Ω 1mA, or 50mV). See the graph “Headroom at
Rails vs. Output Current in the Typical Performance
Characteristics section.
The amplifier is stable driving capacitive loads of up to
500pF.
Rail-to-Rail Output Considerations
In any rail-to-rail voltage output device, the output is lim-
ited to voltages within the supply range.
Since the analog output of the DAC cannot go below
ground, it may limit for the lowest codes as shown in
Figure 4b. Similarly, limiting can occur near full scale
when using the supply as reference. If VFS = VCC and the
DAC full-scale error (FSE) is positive, the output for the
highest codes limits at V
CC
, as shown in Figure 4. No
full-scale limiting can occur if VFS is less than VCC–FSE.
Offset and linearity are defined and tested over the region
of the DAC transfer function where no output limiting can
occur.
LTC2630
17
2630fg
For more information www.linear.com/LTC2630
operation
Board Layout
The PC board should have separate areas for the analog
and digital sections of the circuit. A single, solid ground
plane should be used, with analog and digital signals care-
fully routed over separate areas of the plane. This keeps
digital signals away from sensitive analog signals and
minimizes the interaction between digital ground currents
and the analog section of the ground plane. The resistance
from the LTC2630 GND pin to the ground plane should
be as low as possible. Resistance here will add directly to
the effective DC output impedance of the device (typically
0.1Ω). Note that the LTC2630 is no more susceptible to
this effect than any other parts of this type; on the con-
trary, it allows layout-based performance improvements
to shine rather than limiting attainable performance with
excessive internal resistance.
Another technique for minimizing errors is to use a sepa-
rate power ground return trace on another board layer.
The trace should run between the point where the power
supply is connected to the board and the DAC ground pin.
Thus the DAC ground pin becomes the common point for
analog ground, digital ground, and power ground. When
the LTC2630 is sinking large currents, this current flows
out the ground pin and directly to the power ground trace
without affecting the analog ground plane voltage.
It is sometimes necessary to interrupt the ground plane
to confine digital ground currents to the digital portion of
the plane. When doing this, make the gap in the plane only
as long as it needs to be to serve its purpose and ensure
that no traces cross over the gap.
Opto-Isolated 4mA to 20mA Process Controller
Figure 5 shows how to use an LTC2630Hz to make an
opto-isolated, digitally-controlled 4mA to 20mA transmit-
ter. The transmitter circuitry, including opto-isolation, is
powered by the loop voltage which has a wide range of
5.4V to 80V. The 5V output of the LT
®
3010-5 is used to
set the 4mA offset current and VOUT is used to digitally
control the 0mA to 16mA signal current. The supply cur-
rent for the regulator, DAC, and op amp is well below
the 4mA budget at zero scale. RS senses the total loop
current, which includes the quiescent supply current and
additional current through Q1. Note that at the maximum
loop voltage of 80V, Q1 will dissipate 1.6W when IOUT =
20mA and must have an appropriate heat sink.
ROFFSET and RGAIN are the closest 0.1% values to ideal
for controlling a 4mA to 20mA output as the digital input
varies from zero scale to full scale. Alternatively, ROFFSET
can be a 365k, 1% resistor in series with a 20k trim pot
and RGAIN can be a 75.0k, 1% resistor in series with a 5k
trim pot. The opto-isolators shown will limit the speed of
the serial bus; the 6N139 is an alternative that will allow
higher data rates.
LTC2630
18
2630fg
For more information www.linear.com/LTC2630
2630 F04
INPUT CODE
(b)
OUTPUT
VOLTAGE
NEGATIVE
OFFSET
0V
0V 2,0480 4,095
INPUT CODE
OUTPUT
VOLTAGE
(a)
VREF = VCC
VREF = VCC
(c)
INPUT CODE
OUTPUT
VOLTAGE
POSITIVE
FSE
operation
Figure 4. Effects of Rail-to-Rail Operation on a DAC Transfer Curve (Shown for 12-Bits).
(a) Overall Transfer Function
(b) Effect of Negative Offset for Codes Near Zero
(c) Effect of Positive Full-Scale Error for Codes Near Full Scale
LTC2630
19
2630fg
For more information www.linear.com/LTC2630
SDI
SCK
CS/LD
2630 TA01
0.1µF
OUTPUT
0V TO 2.5V OR
0V TO VCC
VOUT
VCC
LTC2630-LZ12
GND
2.7V TO 5.5V
µP
typical application
12-Bit, 2.7V to 5.5V Single Supply, Voltage Output DAC
LTC2630
20
2630fg
For more information www.linear.com/LTC2630
SC6 Package
6-Lead Plastic SC70
(Reference LTC DWG # 05-08-1638 Rev B)
1.15 – 1.35
(NOTE 4)
1.80 – 2.40
0.15 – 0.30
6 PLCS (NOTE 3)
SC6 SC70 1205 REV B
1.80 – 2.20
(NOTE 4)
0.65 BSC
PIN 1
0.80 – 1.00
1.00 MAX
0.00 – 0.10
REF
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. DETAILS OF THE PIN 1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE INDEX AREA
7. EIAJ PACKAGE REFERENCE IS EIAJ SC-70
8. JEDEC PACKAGE REFERENCE IS MO-203 VARIATION AB
2.8 BSC
0.47
MAX
0.65
REF
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
1.8 REF
1.00 REF
INDEX AREA
(NOTE 6)
0.10 – 0.18
(NOTE 3)
0.26 – 0.46
GAUGE PLANE
0.15 BSC
0.10 – 0.40
SC6 Package
6-Lead Plastic SC70
(Reference LTC DWG # 05-08-1638 Rev B)
package Description
Please refer to http://www.linear.com/product/LTC2630#packaging for the most recent package drawings.
LTC2630
21
2630fg
For more information www.linear.com/LTC2630
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
revision history
REV DATE DESCRIPTION PAGE NUMBER
F 06/12 Corrected units on parameter VOSTC from mV/°C to µV/°C 6
G 06/17 Removed Note 3 7
(Revision history begins at Rev F)
LTC2630
22
2630fg
For more information www.linear.com/LTC2630
LINEAR TECHNOLOGY CORPORATION 2007
LT 0617 REV G • PRINTED IN USA
www.linear.com/LTC2630
relateD parts
typical application
SDI
SCK
CS/LD
1µF
1µF
Q1
2N3440
RS
10Ω
IOUT
VLOOP
5.4V TO 80V
VCC
VOUT
FROM
OPTO-
ISOLATED
INPUTS
LTC2630-HZ
2630 TA02
3.01k
10k
1000PF
+
+
LTC2054
1k
ROFFSET
374k
0.1%
RGAIN
76.8k
0.1%
OPTO-ISOLATORS
500Ω
5V
10k
4N28
SDI
SCK
CS/LD
SDI
SCK
CS/LD
IN OUT
SHDN SENSE
GND
LT3010-5
Figure 5. An Opto-Isolated 4mA to 20mA Process Controller
PART NUMBER DESCRIPTION COMMENTS
LTC1660/LTC1665 Octal 10-/8-Bit VOUT DACs in 16-Pin Narrow SSOP VCC = 2.7V to 5.5V, Micropower, Rail-to-Rail Output
LTC1663 Single 10-Bit VOUT DAC in SOT-23 VCC = 2.7V to 5.5V, 60µA, Internal reference, SMBus Interface
LTC1664 Quad 10-Bit VOUT DAC in 16-Pin Narrow SSOP VCC = 2.7V to 5.5V, Micropower, Rail-to-Rail Output
LTC1669 Single 10-Bit VOUT DAC in SOT-23 VCC = 2.7V to 5.5V, 60µA, Internal reference, I2C Interface
LTC1821 Parallel 16-Bit Voltage Output DAC Precision 16-Bit Settling in 2µs for 10V Step
LTC2600/LTC2610/LTC2620 Octal 16-/14-/12-Bit VOUT DACs in 16-Lead SSOP 250µA per DAC, 2.5V to 5.5V Supply Range, Rail-to-Rail Output,
SPI Serial Interface
LTC2601/LTC2611/LTC2621 Single 16-/14-/12-Bit VOUT DACs in 10-Lead DFN 300µA per DAC, 2.5V to 5.5V Supply Range, Rail-to-Rail Output,
SPI Serial Interface
LTC2602/LTC2612/LTC2622 Dual 16-/14-/12-Bit VOUT DACs in 8-Lead MSOP 300µA per DAC, 2.5V to 5.5V Supply Range, Rail-to-Rail Output,
SPI Serial Interface
LTC2604/LTC2614/LTC2624 Quad 16-/14-/12-Bit VOUT DACs in 16-Lead SSOP 250µA per DAC, 2.5V to 5.5V Supply Range, Rail-to-Rail Output,
SPI Serial Interface
LTC2631 Single 12-/10-/8-Bit I2C VOUT DACs with
10ppm/°C Reference in ThinSOT
180µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference,
Selectable External Ref. Mode, Rail-to-Rail Output, I2C Interface
LTC2640 Single 12-/10-/8-Bit SPI VOUT DACs with
10ppm/°C Reference in ThinSOT
180µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference,
Selectable External Ref. Mode, Rail-to-Rail Output, SPI Interface