LINER LTC2635-LMO10 Quad 12-/10-/8-bit i2c vout dacs with 10ppm/â°c reference Datasheet

LTC2635
Quad 12-/10-/8-Bit I2C VOUT
DACs with 10ppm/°C Reference
Features
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Description
Integrated Precision Reference
2.5V Full-Scale 10ppm/°C (LTC2635-L)
4.096V Full-Scale 10ppm/°C (LTC2635-H)
Maximum INL Error: ±2.5 LSB (LTC2635-12)
Power-On-Reset to Zero-Scale/Mid-Scale/Hi-Z
Low Noise: 0.75mVP-P 0.1Hz to 200kHz
Guaranteed Monotonic Over –40°C to 125°C
Automotive Temperature Range
Selectable Internal or External Reference
2.7V to 5.5V Supply Range (LTC2635-L)
Ultralow Crosstalk Between DACs (3nV•s)
Low Power: 0.6mA at 3V
Double-Buffered Data Latches
Small 16-Pin 3mm × 3mm QFN and 10-Lead MSOP
Packages
Applications
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Mobile Communications
Process Control and Industrial Automation
Power Supply Margining
Portable Equipment
Automotive
The LTC®2635 is a family of quad 12-, 10-, and 8-bit
voltage-output DACs with an integrated, high-accuracy,
low-drift reference in a 16-pin QFN or a 10-lead MSOP
package. It has rail-to-rail output buffers and is guaranteed monotonic. The LTC2635-L has a full-scale output
of 2.5V, and operates from a single 2.7V to 5.5V supply.
The LTC2635-H has a full-scale output of 4.096V, and
operates from a 4.5V to 5.5V supply. Each DAC can also
operate with an external reference, which sets the fullscale output to the external reference voltage.
These DACs communicate via a 2-wire I2C-compatible
serial interface. The LTC2635 operates in both the standard
mode (clock rate of 100kHz) and the fast mode (clock rate
of 400kHz). The LTC2635 incorporates a power-on reset
circuit. Options are available for reset to zero-scale, reset
to mid-scale in internal reference mode, reset to mid-scale
in external reference mode, or reset with all DAC outputs
in a high-impedance state after power-up.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents, including 5396245, 5859606, 6891433,
6937178, 7414561.
Block Diagram
Integral Nonlinerity
INTERNAL
REFERENCE
GND
SWITCH
REF
2
VCC
1
VCC = 3V
INTERNAL REF.
REGISTER
REGISTER
REGISTER
DAC A
REGISTER
VOUTA
DAC D
VREF
(LDAC)
DECODE
CA0
(CA1)
(CA2)
I2C
ADDRESS
DECODE
( ) QFN PACKAGE ONLY
REGISTER
REGISTER
REGISTER
DAC B
REGISTER
VREF
VOUTB
VOUTD
DAC C
I C INTERFACE
0
VOUTC
–1
POWER-ON
RESET
–2
SCL
2
INL (LSB)
VREF
(REFLO)
0
1024
2048
CODE
3072
4095
2635 TA01
SDA
2635 BD
2635fb
LTC2635
Absolute Maximum Ratings
(Notes 1, 2)
Supply Voltage (VCC).................................... –0.3V to 6V
SCL, SDA, REFLO, LDAC............................... –0.3V to 6V
VOUTA-D, CA0, CA1, CA2....... –0.3V to Min (VCC + 0.3V, 6V)
REF..................................... –0.3V to Min (VCC + 0.3V, 6V)
Operating Temperature Range
LTC2635C................................................. 0°C to 70°C
LTC2635H (Note 3)............................. –40°C to 125°C
Maximum Junction Temperature .......................... 150°C
Storage Temperature Range.................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
MS Package....................................................... 300°C
Pin Configuration
REFLO
GND
DNC
VCC
TOP VIEW
TOP VIEW
16 15 14 13
12 VOUTD
VOUTA 1
VOUTB 2
11 VOUTC
17
GND
LDAC 3
10 REF
CA0 4
6
7
8
SCL
DNC
CA2
SDA
9
5
CA1
UD PACKAGE
16-LEAD (3mm s 3mm) PLASTIC QFN
VCC 1
VOUTA 2
VOUTB 3
CA0 4
SCL 5
11
GND
10
9
8
7
6
GND
VOUTD
VOUTC
REF
SDA
MSE PACKAGE
10-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 35°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
TJMAX = 150°C, θJA = 68°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
2635fb
LTC2635
Order Information
LTC2635
C
UD
–L
Z
12
#TR
PBF
LEAD FREE DESIGNATOR
PBF = Lead Free
TAPE AND REEL
TR = 2,500-Piece Tape and Reel
RESOLUTION
12 = 12-Bit
10 = 10-Bit
8 = 8-Bit
POWER-0N RESET
MI = Reset to Mid-Scale in Internal Reference Mode
MX = Reset to Mid-Scale in External Reference Mode (LMX Only)
MO = Reset to Mid-Scale in Internal Reference Mode, DAC Outputs Hi-Z (LMO Only)
Z = Reset to Zero-Scale in Internal Reference Mode
FULL-SCALE VOLTAGE, INTERNAL REFERENCE MODE
L = 2.5V
H = 4.096V
PACKAGE TYPE
UD = 16-Pin QFN
MSE = 10-Lead MSOP
TEMPERATURE GRADE
C = Commercial Temperature Range (0°C to 70°C)
H = Automotive Temperature Range (–40°C to 125°C)
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/
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LTC2635
Product Selection Guide
PART MARKING*
POWER-ON
RESET TO CODE
POWER-ON
REFERENCE
MODE
RESOLUTION
VCC
MAXIMUM
INL
PART NUMBER
QFN
MSOP
VFS WITH INTERNAL
REFERENCE
LTC2635-LMI12
LTC2635-LMI10
LTC2635-LMI8
LDZB
LDZJ
LDZR
LTDZY
LTFBG
LTFBP
2.5V • (4095/4096)
2.5V • (1023/1024)
2.5V • (255/256)
Mid-Scale
Mid-Scale
Mid-Scale
Internal
Internal
Internal
12-Bit
10-Bit
8-Bit
2.7V to 5.5V
2.7V to 5.5V
2.7V to 5.5V
±2.5LSB
±1LSB
±0.5LSB
LTC2635-LMX12
LTC2635-LMX10
LTC2635-LMX8
LDYZ
LDZH
LDZQ
LTDZX
LTFBF
LTFBN
2.5V • (4095/4096)
2.5V • (1023/1024)
2.5V • (255/256)
Mid-Scale
Mid-Scale
Mid-Scale
External
External
External
12-Bit
10-Bit
8-Bit
2.7V to 5.5V
2.7V to 5.5V
2.7V to 5.5V
±2.5LSB
±1LSB
±0.5LSB
LTC2635-LZ12
LTC2635-LZ10
LTC2635-LZ8
LDYY
LDZG
LDZP
LTDZW
LTFBD
LTFBM
2.5V • (4095/4096)
2.5V • (1023/1024)
2.5V • (255/256)
Zero-Scale
Zero-Scale
Zero-Scale
Internal
Internal
Internal
12-Bit
10-Bit
8-Bit
2.7V to 5.5V
2.7V to 5.5V
2.7V to 5.5V
±2.5LSB
±1LSB
±0.5LSB
LTC2635-LMO12**
LTC2635-LMO10**
LTC2635-LMO8**
LFBT
LFBV
LFBW
LTFBX
LTFBY
LTFBZ
2.5V • (4095/4096)
2.5V • (1023/1024)
2.5V • (255/256)
High Impedance
High Impedance
High Impedance
Internal
Internal
Internal
12-Bit
10-Bit
8-Bit
2.7V to 5.5V
2.7V to 5.5V
2.7V to 5.5V
±2.5LSB
±1LSB
±0.5LSB
LTC2635-HMI12
LTC2635-HMI10
LTC2635-HMI8
LDZF
LDZN
LDZV
LTFBC
LTFBK
LTFBS
4.096V • (4095/4096)
4.096V • (1023/1024)
4.096V • (255/256)
Mid-Scale
Mid-Scale
Mid-Scale
Internal
Internal
Internal
12-Bit
10-Bit
8-Bit
4.5V to 5.5V
4.5V to 5.5V
4.5V to 5.5V
±2.5LSB
±1LSB
±0.5LSB
LTC2635-HZ12
LTC2635-HZ10
LTC2635-HZ8
LDZC
LDZK
LDZS
LTDZZ
LTFBH
LTFBQ
4.096V • (4095/4096)
4.096V • (1023/1024)
4.096V • (255/256)
Zero-Scale
Zero-Scale
Zero-Scale
Internal
Internal
Internal
12-Bit
10-Bit
8-Bit
4.5V to 5.5V
4.5V to 5.5V
4.5V to 5.5V
±2.5LSB
±1LSB
±0.5LSB
*Above options are available in a 16-pin QFN package (LTC2635xUD) or 10-lead MSOP package (LTC2635xMSE).
**Contact Linear Technology for other Hi-Z options.
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LTC2635
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.
LTC2635-LMI12/-LMI10/-LMI8/-LMX12/-LMX10/-LMX8/-LZ12/-LZ10/-LZ8/-LMO12/-LMO10/-LM08 (VFS = 2.5V)
LTC2635-8
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
LTC2635-10
MAX
MIN
TYP
LTC2635-12
MAX
MIN
TYP
MAX
UNITS
DC Performance
Resolution
l
8
8
10
12
VCC = 3V, Internal Ref. (Note 4)
l
l
INL
Differential Nonlinearity VCC = 3V, Internal Ref. (Note 4)
Integral Nonlinearity
VCC = 3V, Internal Ref. (Note 4)
l
±0.05
±0.5
±0.2
±1
ZSE
Zero-Scale Error
VCC = 3V, Internal Ref., Code=0
l
0.5
5
0.5
VOS
Offset Error
VCC = 3V, Internal Ref. (Note 5)
l
±0.5
±5
±0.5
VOSTC
VOS Temperature
Coefficient
VCC = 3V, Internal Ref.
GE
Gain Error
VCC = 3V, Internal Ref.
GETC
Gain Temperature
Coefficient
VCC = 3V, Internal Ref. (Note 10)
C-Grade
H-Grade
Monotonicity
DNL
Load Regulation
ROUT
DC Output Impedance
Internal Ref., Mid-Scale,
VCC = 3V ± 10%,
–5mA ≤ IOUT ≤ 5mA
VCC = 5V±10%,
–10mA ≤ IOUT ≤ 10mA
Internal Ref., Mid-Scale,
VCC = 3V ± 10%,
–5mA ≤ IOUT ≤ 5mA
VCC = 5V±10%,
–10mA ≤ IOUT ≤ 10mA
10
±0.2
l
Bits
±0.5
±1
LSB
±1
±2.5
LSB
5
0.5
5
mV
±5
±0.5
±5
mV
±10
±0.8
±0.2
±10
±0.8
±0.2
10
10
10
µV/°C
±0.8
10
10
10
%FSR
ppm/°C
ppm/°C
l
0.009 0.016
0.035 0.064
0.14
0.256 LSB/mA
l
0.009 0.016
0.035 0.064
0.14
0.256 LSB/mA
l
0.09
0.156
0.09
0.156
0.09
0.156
Ω
l
0.09
0.156
0.09
0.156
0.09
0.156
Ω
SYMBOL
PARAMETER
CONDITIONS
VOUT
DAC Output Span
External Reference
Internal Reference
PSR
Power Supply Rejection
VCC = 3V ± 10% or 5V ± 10%
ISC
Short Circuit Output Current (Note 6)
Sinking
Sourcing
VFS = VCC = 5.5V
Zero-Scale; VOUT Shorted to VCC
Full-Scale; VOUT Shorted to GND
DAC ISD
12
±0.5
±10
Bits
MIN
TYP
MAX
UNITS
0 to VREF
0 to 2.5
V
V
–80
dB
l
l
27
–28
48
–48
mA
mA
DAC Output Current in High Impedance Mode MO Options Only
Sinking
Sourcing
l
l
0.05
–0.001
2
–0.1
µA
µA
Power Supply
VCC
Positive Supply Voltage
For Specified Performance
l
5.5
V
ICC
Supply Current (Note 7)
VCC = 3V, VREF = 2.5V, External Reference
VCC = 3V, Internal Reference
VCC = 5V VREF = 2.5V, External Reference
VCC = 5V, Internal Reference
l
l
l
l
2.7
0.5
0.6
0.6
0.7
0.7
0.8
0.8
0.9
mA
mA
mA
mA
ISD
Supply Current in Power-Down Mode
(Note 7)
VCC = 5V, C-Grade
VCC = 5V, H-Grade
l
l
1
1
20
30
µA
µA
2635fb
LTC2635
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.
LTC2635-LMI12/-LMI10/-LMI8/-LMX12/-LMX10/-LMX8/-LZ12/-LZ10/-LZ8/-LMO12/-LMO10/-LM08 (VFS = 2.5V)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
VCC
V
200
kΩ
Reference Input
Input Voltage Range
l
1
Resistance
l
120
Capacitance
IREF
Reference Current, Power-Down Mode
160
14
DAC Powered Down
l
pF
0.005
1.5
µA
1.25
1.26
V
Reference Output
Output Voltage
l
1.24
Reference Temperature Coefficient
±10
ppm/°C
Output Impedance
0.5
kΩ
Capacitive Load Driving
10
µF
2.5
mA
Short Circuit Current
VCC = 5.5V, REF Shorted to GND
VIL
Low Level Input Voltage
(SDA and SCL)
(Note 14)
l
–0.5
VIH
High Level Input Voltage
(SDA and SCL)
(Note 11)
l
0.7VCC
VIL(CAn)
Low Level Input Voltage on CAn
(n = 0, 1,2)
See Test Circuit 1
l
VIH(CAn)
High Level Input Voltage on CAn
(n = 0, 1,2)
See Test Circuit 1
l
RINH
Resistance from CAn (n = 0, 1,2)
to VCC to Set CAn = VCC
See Test Circuit 2
l
10
kΩ
RINL
Resistance from CAn (n = 0, 1,2)
to GND to Set CAn = GND
See Test Circuit 2
l
10
kΩ
RINF
Resistance from CAn (n = 0, 1,2)
to VCC or GND to Set CAn = Float
See Test Circuit 2
l
2
VOL
Low Level Output Voltage
Sink Current = 3mA
l
0
0.4
V
tOF
Output Fall Time
VO = VIH(MIN) to VO = VIL(MAX),
CB = 10pF to 400pF (Note 12)
l
20 + 0.1CB
250
ns
tSP
Pulse Width of Spikes Suppressed
by Input Filter
l
0
50
ns
IIN
Input Leakage
0.1VCC ≤ VIN ≤ 0.9VCC
l
1
µA
CIN
I/O Pin Capacitance
(Note 8)
l
10
pF
CB
Capacitive Load for Each Bus Line
l
400
pF
CCAn
External Capacitive Load on Address
Pin CAn (n = 0, 1,2)
l
10
pF
Digital I/O
0.3VCC
V
V
0.15VCC
0.85VCC
V
V
MΩ
2635fb
LTC2635
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.
LTC2635-LMI12/-LMI10/-LMI8/-LMX12/-LMX10/-LMX8/-LZ12/-LZ10/-LZ8/-LMO12/-LMO10/-LM08 (VFS = 2.5V)
SYMBOL
PARAMETER
CONDITIONS
Settling Time
VCC = 3V (Note 9)
±0.39% (±1LSB at 8 Bits)
±0.098% (±1LSB at 10 Bits)
±0.024% (±1LSB at 12 Bits)
MIN
TYP
MAX
UNITS
AC Performance
tS
3.5
4.1
4.4
Voltage Output Slew Rate
1
Capacitive Load Driving
en
µs
µs
µs
V/µs
500
pF
2.1
nV • s
Glitch Impulse
At Mid-Scale Transition
DAC-to-DAC Crosstalk
1 DAC Held at FS, 1 DAC Switched 0 to FS
2.6
nV • s
Multiplying Bandwidth
External Reference
320
kHz
Output Voltage Noise Density
At f = 1kHz, External Reference
At f = 10kHz, External Reference
At f = 1kHz, Internal Reference
At f = 10kHz, Internal Reference
180
160
200
180
nV/√Hz
nV/√Hz
nV/√Hz
nV/√Hz
Output Voltage Noise
0.1Hz to 10Hz, External Reference
0.1Hz to 10Hz, Internal Reference
0.1Hz to 200kHz, External Reference
0.1Hz to 200kHz, Internal Reference
CREF = 0.1µF
35
40
680
730
µVP-P
µVP-P
µVP-P
µVP-P
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 13)
LTC2635-LMI12/-LMI10/-LMI8/-LMX12/-LMX10/-LMX8/-LZ12/-LZ10/-LZ8/-LMO12/-LMO10/-LM08 (VFS = 2.5V)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
fSCL
SCL Clock Frequency
l
0
400
kHz
tHD(STA)
Hold Time (Repeated) Start Condition
l
0.6
µs
tLOW
Low Period of the SCL Clock Pin
l
1.3
µs
tHIGH
High Period of the SCL Clock Pin
l
0.6
µs
tSU(STA)
Set-Up Time for a Repeated Start Condition
l
0.6
µs
tHD(DAT)
Data Hold Time
l
0
0.9
µs
tSU(DAT)
Data Set-Up Time
l
100
tr
Rise Time of Both SDA and SCL Signals
(Note 12)
l
20 + 0.1CB
300
ns
ns
tf
Fall Time of Both SDA and SCL Signals
(Note 12)
l
20 + 0.1CB
300
ns
tSU(STO)
Set-Up Time for Stop Condition
l
0.6
µs
tBUF
Bus Free Time Between a Stop and Start Condition
l
1.3
µs
t1
Falling Edge of 9th Clock of the 3rd Input Byte to LDAC
l
400
ns
LDAC Low Pulse Width
l
20
ns
t2
High or Low Transition
2635fb
LTC2635
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.
LTC2635-HMI12/-HMI10/-HMI8/-HZ12/-HZ10/-HZ8 (VFS = 4.096V)
LTC2635-8
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
LTC2635-10
MAX
MIN
TYP
LTC2635-12
MAX
MIN
TYP
MAX
UNITS
DC Performance
l
8
10
12
Bits
VCC = 5V, Internal Ref. (Note 4)
l
8
10
12
Bits
DNL
Differential Nonlinearity VCC = 5V, Internal Ref. (Note 4)
l
INL
Integral Nonlinearity
VCC = 5V, Internal Ref. (Note 4)
l
0.5
5
0.5
5
0.5
5
mV
±0.5
±5
±0.5
±5
±0.5
±5
mV
Resolution
Monotonicity
±0.5
±0.05
±0.5
±0.5
±0.2
±1
±1
±1
LSB
±2.5
LSB
ZSE
Zero-Scale Error
VCC = 5V, Internal Ref., Code=0
l
VOS
Offset Error
VCC = 5V, Internal Ref. (Note 5)
l
VOSTC
VOS Temperature
Coefficient
VCC = 5V, Internal Reference
GE
Gain Error
VCC = 5V, Internal Reference
GETC
Gain Temperature
Coefficient
VCC = 5V, Internal Ref. (Note 10)
C-Grade
H-Grade
Load Regulation
Internal Reference, Mid-Scale,
VCC = 5V ± 10%,
–10mA ≤ IOUT ≤ 10mA
l
0.006
0.01
0.022
0.04
0.09
0.16
LSB/mA
DC Output
Internal Reference, Mid-Scale,
VCC = 5V ± 10%,
–10mA ≤ IOUT ≤ 10mA
l
0.09
0.156
0.09
0.156
0.09
0.156
Ω
ROUT
±10
l
±0.2
±10
±0.8
±0.2
±10
±0.8
±0.2
10
10
10
10
SYMBOL
PARAMETER
CONDITIONS
VOUT
DAC Output Span
External Reference
Internal Reference
PSR
Power Supply Rejection
VCC = 5V±10%
ISC
Short Circuit Output Current (Note 6)
Sinking
Sourcing
VFS = VCC = 5.5V
Zero-Scale; VOUT Shorted to VCC
Full-Scale; VOUT Shorted to GND
l
l
VCC
Positive Supply Voltage
For Specified Performance
l
ICC
Supply Current (Note 7)
VCC = 3V, VREF = 4.096V, External Reference
VCC = 3V, Internal Reference
l
l
ISD
Supply Current in Power-Down Mode
(Note 7)
VCC = 5V, C-Grade
VCC = 5V, H-Grade
l
l
µV/°C
±0.8
10
10
MIN
TYP
%FSR
ppm/°C
ppm/°C
MAX
UNITS
0 to VREF
0 to 4.096
V
V
–80
dB
27
–28
48
–48
mA
mA
5.5
V
0.6
0.7
0.8
0.9
mA
mA
1
1
20
30
µA
µA
Power Supply
4.5
2635fb
LTC2635
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.
LTC2635-HMI12/-HMI10/-HMI8/-HZ12/-HZ10/-HZ8 (VFS = 4.096V)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
VCC
V
200
kΩ
Reference Input
Input Voltage Range
l
1
Resistance
l
120
Capacitance
IREF
Reference Current, Power-Down Mode
160
14
DAC Powered Down
l
pF
0.005
1.5
µA
2.048
2.064
V
Reference Output
Output Voltage
l
2.032
Reference Temperature Coefficient
±10
ppm/°C
Output Impedance
0.5
kΩ
Capacitive Load Driving
10
µF
4
mA
Short Circuit Current
VCC = 5.5V, REF Shorted to GND
VIL
Low Level Input Voltage
(SDA and SCL)
(Note 14)
l
–0.5
VIH
High Level Input Voltage
(SDA and SCL)
(Note 11)
l
0.7VCC
VIL(CAn)
Low Level Input Voltage on CAn
(n = 0, 1,2)
See Test Circuit 1
l
VIH(CAn)
High Level Input Voltage on CAn
(n = 0, 1,2)
See Test Circuit 1
l
RINH
Resistance from CAn (n = 0, 1,2)
to VCC to Set CAn = VCC
See Test Circuit 2
l
10
kΩ
RINL
Resistance from CAn (n = 0, 1,2)
to GND to Set CAn = GND
See Test Circuit 2
l
10
kΩ
RINF
Resistance from CAn (n = 0, 1,2)
to VCC or GND to Set CAn = Float
See Test Circuit 2
l
2
VOL
Low Level Output Voltage
Sink Current = 3mA
l
0
0.4
V
tOF
Output Fall Time
VO = VIH(MIN) to VO = VIL(MAX),
CB = 10pF to 400pF (Note 12)
l
20 + 0.1CB
250
ns
tSP
Pulse Width of Spikes Suppressed
by Input Filter
l
0
50
ns
IIN
Input Leakage
0.1VCC ≤ VIN ≤ 0.9VCC
l
1
µA
CIN
I/O Pin Capacitance
(Note 8)
l
10
pF
CB
Capacitive Load for Each Bus Line
l
400
pF
CCAn
External Capacitive Load on Address
Pin CAn (n=0, 1,2)
l
10
pF
Digital I/O
0.3VCC
V
V
0.15VCC
0.85VCC
V
V
MΩ
2635fb
LTC2635
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.
LTC2635-HMI12/-HMI10/-HMI8/-HZ12/-HZ10/-HZ8 (VFS = 4.096V)
SYMBOL
PARAMETER
CONDITIONS
Settling Time
VCC = 5V (Note 9)
±0.39% (±1LSB at 8 Bits)
±0.098% (±1LSB at 10 Bits)
±0.024% (±1LSB at 12 Bits)
MIN
TYP
MAX
UNITS
AC Performance
tS
3.9
4.3
5
Voltage Output Slew Rate
1
Capacitive Load Driving
en
µs
µs
µs
V/µs
500
pF
Glitch Impulse
At Mid-Scale Transition
3
nV • s
DAC-to-DAC Crosstalk
1 DAC Held at FS, 1 DAC Switched 0 to FS
Multiplying Bandwidth
External Reference
320
3
nV • s
kHz
Output Voltage Noise Density
At f = 1kHz, External Reference
At f = 10kHz, External Reference
At f = 1kHz, Internal Reference
At f = 10kHz, Internal Reference
180
160
250
230
nV/√Hz
nV/√Hz
nV/√Hz
nV/√Hz
Output Voltage Noise
0.1Hz to 10Hz, External Reference
0.1Hz to 10Hz, Internal Reference
0.1Hz to 200kHz, External Reference
0.1Hz to 200kHz, Internal Reference
CREF = 0.1µF
35
50
680
750
µVP-P
µVP-P
µVP-P
µVP-P
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 13)
LTC2635-HMI12/-HMI10/-HMI8/-HZ12/-HZ10/-HZ8 (VFS = 4.096V)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
fSCL
SCL Clock Frequency
l
0
400
kHz
tHD(STA)
Hold Time (Repeated) Start Condition
l
0.6
µs
tLOW
Low Period of the SCL Clock Pin
l
1.3
µs
tHIGH
High Period of the SCL Clock Pin
l
0.6
µs
tSU(STA)
Set-Up Time for a Repeated Start Condition
l
0.6
µs
tHD(DAT)
Data Hold Time
l
0
0.9
µs
tSU(DAT)
Data Set-Up Time
l
100
tr
Rise Time of Both SDA and SCL Signals
(Note 12)
l
20+0.1CB
300
ns
ns
tf
Fall Time of Both SDA and SCL Signals
(Note 12)
l
20+0.1CB
300
ns
tSU(STO)
Set-Up Time for Stop Condition
l
0.6
µs
tBUF
Bus Free Time Between a Stop and Start Condition
l
1.3
µs
t1
Falling Edge of 9th Clock of the 3rd Input Byte to LDAC
l
400
ns
LDAC Low Pulse Width
l
20
ns
t2
High or Low Transition
2635fb
10
LTC2635
Electrical Characteristics
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. High temperatures degrade operating lifetimes. Operating lifetime
is derated at temperatures greater than 105°C. Operating at temperatures
above 90°C and with VCC > 4V requires VCC slew rates to be no greater than
73mV/ms.
Note 4. 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 7. Digital inputs at 0V or VCC.
Note 8. Guaranteed by design and not production tested.
Note 9. Internal Reference mode. DAC is stepped 1/4 scale to 3/4 scale and
3/4 scale to 1/4 scale. Load is 2kΩ in parallel with 100pF to GND.
Note 10. Temperature coefficient is calculated by dividing the maximum
change in output voltage by the specified temperature range.
Note 11. Maximum VIH = VCC(MAX) + 0.5V.
Note 12. CB = capacitance of one bus line in pF.
Note 13. All values refer to VIH = VIH(MIN) and VIL = VIL(MAX) levels.
Note 14. Minimum VIL exceeds the Absolute Maximum rating. This condition
won’t damage the IC, but could degrade performance.
Note 5. Inferred from measurement at code 16 (LTC2635-12), code 4
(LTC2635-10) or code 1 (LTC2635-8), and at full-scale.
Note 6. 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.
2635fb
11
LTC2635
Typical Performance Characteristics
TA = 25°C, unless otherwise noted.
LTC2635-L12 (Internal Reference, VFS = 2.5V)
Integral Nonlinearity (INL)
1.0
Differential Nonlinearity (DNL)
1.0
VCC = 3V
0.5
DNL (LSB)
INL (LSB)
0.5
0
–0.5
–1.0
VCC = 3V
0
–0.5
1024
0
2048
CODE
3072
–1.0
4095
1024
0
2048
CODE
3072
2635 G01
INL vs Temperature
1.0
DNL (LSB)
INL (LSB)
0
–1.0
–50 –25
25 50 75 100 125 150
TEMPERATURE (°C)
DNL (POS)
0
DNL (NEG)
–1.0
–50 –25
0
1.240
–50 –25
25 50 75 100 125 150
TEMPERATURE (°C)
0
2635 G04
Settling to ±1 LSB Rising
25 50 75 100 125 150
TEMPERATURE (°C)
2635 G05
Settling to ±1 LSB Falling
9th CLOCK OF 3rd
DATA BYTE
3/4 SCALE TO 1/4 SCALE STEP
VCC = 3V, VFS = 2.5V
RL = 2k, CL = 100pF
AVERAGE OF 256 EVENTS
VOUT
1 LSB/DIV
4.4µs
3.3µs
VOUT
1 LSB/DIV
1.250
1.245
2635 G03
SCL
5V/DIV
VCC = 3V
1.255
–0.5
INL (NEG)
0
1.260
VCC = 3V
0.5
INL (POS)
–0.5
Reference Output Voltage vs
Temperature
DNL vs Temperature
VCC = 3V
0.5
2635 G02
VREF (V)
1.0
4095
1/4 SCALE TO 3/4 SCALE STEP
VCC = 3V, VFS = 2.5V
RL = 2k, CL = 100pF
AVERAGE OF 256 EVENTS
2µs/DIV
2635 G06
SCL
5V/DIV
9th CLOCK OF 3rd
DATA BYTE
2µs/DIV
2635 G07
2635fb
12
LTC2635
Typical Performance Characteristics
TA = 25°C, unless otherwise noted.
LTC2635-H12 (Internal Reference, VFS = 4.096V)
Integral Nonlinearity (INL)
1.0
Differential Nonlinearity (DNL)
1.0
VCC = 5V
0.5
DNL (LSB)
INL (LSB)
0.5
0
–0.5
–1.0
VCC = 5V
0
–0.5
1024
0
2048
CODE
3072
–1.0
4095
0
1024
2048
CODE
3072
2635 G08
INL vs Temperature
1.0
VCC = 5V
INL (POS)
2.068
VCC = 5V
0.5
0
INL (NEG)
–0.5
–1.0
–50 –25
Reference Output Voltage vs
Temperature
DNL (POS)
0
DNL (NEG)
–0.5
0
25 50 75 100 125 150
TEMPERATURE (°C)
–1.0
–50 –25
0
2.028
–50 –25
25 50 75 100 125 150
TEMPERATURE (°C)
0
2635 G11
Settling to ±1 LSB Rising
25 50 75 100 125 150
TEMPERATURE (°C)
2635 G12
Settling to ±1 LSB Falling
3/4 SCALE TO
1/4 SCALE STEP
VCC = 5V, VFS = 4.095V
RL = 2k, CL = 100pF
AVERAGE OF 256 EVENTS
9th CLOCK OF 3rd
DATA BYTE
VOUT
1 LSB/DIV
3.9µs
VOUT
1 LSB/DIV
2.048
2.038
2635 G10
SCL
5V/DIV
VCC = 5V
2.058
VREF (V)
INL (LSB)
0.5
2635 G09
DNL vs Temperature
DNL (LSB)
1.0
4095
5µs
1/4 SCALE TO 3/4 SCALE STEP
VCC = 5V, VFS = 4.095V
RL = 2k, CL = 100pF
AVERAGE OF 256 EVENTS
2µs/DIV
2635 G13
SCL
5V/DIV
9th CLOCK OF 3rd
DATA BYTE
2µs/DIV
2635 G14
2635fb
13
LTC2635
Typical Performance Characteristics
TA = 25°C, unless otherwise noted.
LTC2635-10
Integral Nonlinearity (INL)
1.0
Differential Nonlinearity (DNL)
1.0
VCC = 3V
VFS = 2.5V
INTERNAL REF
0.5
DNL (LSB)
INL (LSB)
0.5
0
–0.5
–1.0
VCC = 3V
VFS = 2.5V
INTERNAL REF
0
–0.5
256
0
512
CODE
768
–1.0
1023
256
0
512
CODE
768
2635 G15
1023
2635 G16
LTC2635-8
Integral Nonlinearity (INL)
0.50
Differential Nonlinearity (DNL)
0.50
VCC = 3V
VFS = 2.5V
INTERNAL REF
0.25
DNL (LSB)
INL (LSB)
0.25
0
–0.25
–0.50
VCC = 3V
VFS = 2.5V
INTERNAL REF
0
–0.25
0
64
128
CODE
192
–0.50
255
64
0
128
CODE
2635 G17
192
255
2635 G18
LTC2635
8
6
Current Limiting
0.20
VCC = 5V (LTC2635-H)
VCC = 5V (LTC2635-L)
VCC = 3V (LTC2635-L)
0.15
0.10
2
ΔVOUT (V)
ΔVOUT (mV)
4
0
–2
–4
VCC = 5V (LTC2635-H)
VCC = 5V (LTC2635-L)
VCC = 3V (LTC2635-L)
2
0.05
0
–0.05
–0.01
–6
INTERNAL REF.
CODE = MID-SCALE
–8
–10
–30
Offset Error vs Temperature
3
OFFSET ERROR (mV)
Load Regulation
10
–20
–10
0
10
IOUT (mA)
20
30
2635 G19
–0.15
–0.20
–30
INTERNAL REF.
CODE = MID-SCALE
–20
–10
0
10
IOUT (mA)
20
30
2635 G20
1
0
–1
–2
–3
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
2635 G21
2635fb
14
LTC2635
Typical Performance Characteristics
TA = 25°C, unless otherwise noted.
LTC2635
Large-Signal Response
Mid-Scale Glitch Impulse
Power-On Reset Glitch
LTC2635-L
9th CLOCK OF 3rd
DATA BYTE
SCL
5V/DIV
VOUT
0.5V/DIV
VCC
2V/DIV
LTC2635-H12, VCC = 5V
3nV • s TYP
VOUT
5mV/DIV
ZERO SCALE
VOUT
5mV/DIV
LTC2635-L12, VCC = 3V
2.1nV • s TYP
VFS = VCC = 5V
1/4 SCALE to 3/4 SCALE
2µs/DIV
2µs/DIV
2635 G23
200µs/DIV
2635 G22
2635 G24
Headroom at Rails vs
Output Current
Exiting Power-Down to Mid-Scale
5.0
VCC = 5V
INTERNAL
REFERENCE
5V SOURCING
4.5
4.0
3V (LTC2635-L) SOURCING
3.0
VCC
2V/DIV
9th CLOCK OF 3rd
DATA BYTE
LTC2635-H
2.5
2.0
1.5
DACs A-C IN
POWER-DOWN
MODE
0
1
2
3
LTC2635-H
4 5 6
IOUT (mA)
7
8
9
5µs/DIV
10
2635 G26
2635 G27
Exiting Power-Down for Hi-Z
Option
SWEEP SDA, SCL
BETWEEN
0V AND VCC
1.4
9th CLOCK OF 3rd
DATA BYTE
SCL
5V/DIV
1.2
VCC = 5V
1.0
0.8
0
1
2
3
LOGIC VOLTAGE (V)
HIGH-IMPEDANCE
(POWER-DOWN) MODE
DAC OUTPUT SET
TO MID-SCALE
VOUT
500mV/DIV
VCC = 3V
(LTC2635-L)
0.6
0.4
200µs/DIV
2635 G25
Supply Current vs Logic Voltage
1.6
LTC2635-L
VOUT
0.5V/DIV
3V (LTC2635-L) SINKING
0.5
0
VOUT
0.5V/DIV
5V SINKING
1.0
ICC(mA)
VOUT (V)
3.5
SCL
5V/DIV
Power-On Reset to Mid-Scale
4
5
2635 G28
2µs/DIV
2635 G29
LTC2635-LMO, VCC = 3V
DAC OUTPUT DRIVEN BY
1V SOURCE THROUGH
15k RESISTOR
2635fb
15
LTC2635
Typical Performance Characteristics
TA = 25°C, unless otherwise noted.
LTC2635
Noise Voltage vs Frequency
500
0
NOISE VOLTAGE (nV/√Hz)
–2
–4
–8
–10
–12
VCC = 5V
VREF(DC) = 2V
VREF(AC) = 0.2VP-P
CODE = FULL-SCALE
–14
–16
–18
1k
10k
100k
FREQUENCY (Hz)
VCC = 5V
CODE = MID-SCALE
INTERNAL REF
VCC = 5.5V
0.8 GAIN ERROR OF 4 CHANNELS
0.6
300
LTC2635-H
200
LTC2635-L
100
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
1M
0
100
2635 G31
1k
10k
100k
FREQUENCY (Hz)
–1.0
1M
1
1.5
2 2.5 3 3.5 4 4.5
REFERENCE VOLTAGE (V)
0.1Hz to 10Hz Voltage Noise
5
5.5
2635 G33
2634 G32
DAC-to-DAC Crosstalk (Dynamic)
Gain Error vs Temperature
1.0
VCC = 5V, VFS = 2.5V
CODE = MID-SCALE
INTERNAL REF
SCL
5V/DIV
9th CLOCK OF 3rd
DATA BYTE
GAIN ERROR (%FSR)
dB
–6
400
Gain Error vs Reference Input
1.0
GAIN ERROR (%FSR)
Mulitplying Bandwidth
2
1 DAC
SWITCH 0-FS
2V/DIV
10µV/DIV
VOUT
2mV/DIV
LTC2635-H12, VCC = 5V
3nV • s TYPICAL CREF = 0.1µF
2µs/DIV
1s/DIV
2635 G34
2635 G35
0.5
0
–0.5
–1.0
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
2635 G36
2635fb
16
LTC2635
Pin Functions
(MSOP/QFN)
VCC (Pin 1/Pin 16): Supply Voltage Input. 2.7V ≤ VCC ≤
5.5V (LTC2635-L) or 4.5V ≤ VCC ≤ 5.5V (LTC2635-H).
Bypass to GND with a 0.1µF capacitor.
VOUTA to VOUTD (Pins 2, 3, 8, 9/Pins 1, 2, 11, 12): DAC
Analog Voltage Outputs.
LDAC (Pin 3, QFN Only): Asynchronous DAC Update. A
falling edge on this input after four bytes (slave address
byte plus three data bytes) have been written into the part
immediately updates the DAC registers with the contents
of the input registers (similar to a software update). A
low on this input without a complete 32-bit (four bytes
including the slave address) data write transfer to the part
does not update the DAC output. A low on the LDAC pin
powers up the DACs. A software power down command
is ignored if LDAC is low.
CA0 (Pin 4/Pin 4): Chip Address Bit 0. Tie this pin to VCC,
GND or leave it floating to select an I2C slave address for
the part (see Tables 1 and 2).
SCL (Pin 5/Pin 5): Serial Clock Input Pin. Data is shifted
into the SDA pin at the rising edges of the clock. This
high-impedance pin requires a pull-up resistor or current
source to VCC.
SDA (Pin 6/Pin 8): Serial Data Bidirectional Pin. Data is
shifted into the SDA pin and acknowledged by the SDA
pin. This pin is high impedance while data is shifted in.
Open drain N-channel output during acknowledgment. SDA
requires a pull-up resistor or current source to VCC.
REF (Pin 7/Pin 10): Reference Voltage Input or Output.
When External Reference mode is selected, REF is an
input (1V ≤ VREF ≤ VCC) where the voltage supplied sets
the full-scale DAC output voltage. When Internal Reference
is selected, the 10ppm/°C 1.25V (LTC2635-L) or 2.048V
(LTC2635-H) internal reference (half full-scale) is available
at the pin. This output may be bypassed to GND with up
to 10µF, and must be buffered when driving an external
DC load current.
DNC (Pins 6, 15, QFN Only): Do Not Connect These
Pins.
CA2 (Pin 7, QFN Only): Chip Address Bit 2. Tie this pin to
VCC, GND or leave it floating to select an I2C slave address
for the part (see Table 1).
CA1 (Pin 9, QFN Only): Chip Address Bit 1. Tie this pin to
VCC, GND or leave it floating to select an I2C slave address
for the part (see Table 1).
GND (Pin 10, Exposed Pad Pin 11/Pin 14, Exposed Pad
Pin 17): Ground. Must be soldered to PCB ground.
REFLO (Pin 13, QFN Only): Reference Low Pin. The voltage at this pin sets the zero-scale voltage of all DACs. This
pin must be tied to GND.
2635fb
17
LTC2635
Block Diagram
INTERNAL
REFERENCE
GND
SWITCH
REF
VREF
VCC
REGISTER
REGISTER
DAC A
REGISTER
VOUTA
REGISTER
(REFLO)
DAC D
VREF
(LDAC)
DECODE
CA0
(CA1)
(CA2)
I2C
ADDRESS
DECODE
( ) QFN PACKAGE ONLY
REGISTER
REGISTER
REGISTER
DAC B
REGISTER
VREF
VOUTB
VOUTD
DAC C
VOUTC
POWER-ON
RESET
SCL
I2C INTERFACE
SDA
2635 BD
2635fb
18
LTC2635
TEST CIRCUITS
Test Circuits for I2C Digital I/O (See Electrical Characteristics)
Test Circuit 1
Test Circuit 2
VDD
100Ω
CAn
RINH/RINL/RINF
CAn
VIH(CAn)/VIL(CAn)
2635 TC01
2635 TC02
GND
TIMING Diagrams
SDA
tf
tLOW
tSU(DAT)
tr
tHD(STA)
tr
tSP
tBUF
tr
SCL
tHD(STA)
S
tHD(DAT) tHIGH
tSU(STA)
Sr
ALL VOLTAGE LEVELS REFER TO VIH(MIN) AND VIL(MAX) LEVELS
tSU(STO)
P
S
2635 F01
Figure 1. I2C Timing
2635fb
19
LTC2635
TIMING Diagrams
SLAVE ADDRESS
1ST DATA BYTE
2ND DATA BYTE
3RD DATA BYTE
START
SDA
A6
A5
A4
A3
A2
A1
A0
W ACK C3
C2
C1 C0
A3
A2
A1
A0 ACK
SCL
1
2
3
4
5
6
7
8
2
3
5
6
7
8
9
1
4
9
ACK
1
2
3
4
5
6
7
8
9
1
2
3
4
X
X
X
X ACK
5
6
7
8
9
t1
t2
LDAC
2635 F02a
Figure 2a. Typical LTC2635 Write Transaction
9TH CLOCK
OF 3RD
DATA BYTE
SCL
t1
LDAC
2635 F02b
Figure 2b. LTC2635 LDAC Timing (QFN Package Only)
2635fb
20
LTC2635
OPERATION
The LTC2635 is a family of quad voltage output DACs in
16-pin QFN and 10-lead MSOP packages. Each DAC can
operate rail-to-rail using an external reference, or with its
full-scale voltage set by an integrated reference. Eighteen
combinations of accuracy (12-, 10-, and 8-bit), power-on
reset value (zero-scale, mid-scale in internal reference
mode, or mid-scale in external reference mode), DAC
power-down output load (high impedance or 200kΩ),
and full-scale voltage (2.5V or 4.096V) are available. The
LTC2635 is controlled using a 2-wire I2C interface.
Power-On Reset
The LTC2635-HZ/-LZ clear the output to zero-scale when
power is first applied, making system initialization consistent 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 LTC2635
contains circuitry to reduce the power-on glitch: the
analog output typically rises less than 5mV above zeroscale during power on. 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 LTC2635-HMI/-LMI/-LMX provide an alternative
reset, setting the output to mid-scale when power is first
applied. The LTC2635-LMI and LTC2635-HMI power
up in internal reference mode, with the output set to a
mid-scale voltage of 1.25V and 2.048V, respectively. The
LTC2635-LMX power-up in external reference mode, with
the output set to mid-scale of the external reference. The
LTC2635-LMO powers up in internal reference mode with
all the DAC channels placed in the high-impedance state
(powered-down). Input and DAC registers are set to the
mid-scale code, and only the internal reference is powered
up, causing supply current to be typically 100µA upon
power up. Default reference mode selection is described
in the Reference Modes section.
Power Supply Sequencing
The voltage at REF (Pin 10 – QFN, Pin 7 – MSOP) must
be kept within the range –0.3V ≤ VREF ≤ VCC + 0.3V (see
Absolute Maximum Ratings). Particular care should be
taken to observe these limits during power supply turnon and turn-off sequences, when the voltage at VCC is in
transition.
Transfer Function
The digital-to-analog transfer function is
k 
VOUT(IDEAL) =   ( VREF – VREFLO ) + VREFLO
 2N 
where k is the decimal equivalent of the binary DAC input
code, N is the resolution, and VREF is either 2.5V (LTC2635LMI/-LMX/-LMO/-LZ) or 4.096V (LTC2635-HMI/-HZ) when
in Internal Reference mode, and the voltage at REF when
in External Reference mode.
I2C Serial Interface
The LTC2635 communicates with a host using the standard 2-wire I2C interface. The timing diagrams (Figures
1 and 2) show the timing relationship of the signals on
the bus. The two bus lines, SDA and SCL, must be high
when the bus is not in use. External pull-up resistors or
current sources are required on these lines. The value of
these pull-up resistors is dependent on the power supply
and can be obtained from the I2C specifications. For an I2C
bus operating in the fast mode, an active pull-up will be
necessary if the bus capacitance is greater than 200pF.
The LTC2635 is a receive-only (slave) device. The master
can write to the LTC2635. The LTC2635 will not acknowledge (NAK) a read request from the master.
START (S) and STOP (P) Conditions
When the bus is not in use, both SCL and SDA must be
high. A bus master signals the beginning of a communication to a slave device by transmitting a START condition.
A START condition is generated by transitioning SDA from
high to low while SCL is high.
When the master has finished communicating with the
slave, it issues a STOP condition. A STOP condition is
generated by transitioning SDA from low to high while
SCL is high. The bus is then free for communication with
another I2C device.
2635fb
21
LTC2635
OPERATION
Acknowledge
Table 1. Slave Address Map (QFN Package)
The Acknowledge (ACK) signal is used for handshaking
between the master and the slave. An ACK (active LOW)
generated by the slave lets the master know that the latest byte of information was properly received. The ACK
related clock pulse is generated by the master. The master
releases the SDA line (HIGH) during the ACK clock pulse.
The slave-receiver must pull down the SDA bus line during the ACK clock pulse so that it remains a stable LOW
during the HIGH period of this clock pulse. The LTC2635
responds to a write by a master in this manner but does
not acknowledge a read operation; in that case, SDA is
retained HIGH during the period of the ACK clock pulse.
CA2
CA1
GND
GND
Chip Address
The state of pins CA0, CA1 and CA2 (CA1 and CA2 are
only available on the QFN package) determines the slave
address of the part. These pins can be each set to any
one of three states: VCC, GND or float. This results in 27
(QFN Package) or 3 (MSOP Package) selectable addresses
for the part. The slave address assignments are shown
in Tables 1 and 2.
In addition to the address selected by the address pins,
the part also responds to a global address. This address
allows a common write to all LTC2635 parts to be accomplished using one 3-byte write transaction on the
I2C bus. The global address, listed at the end of Tables
1 and 2, is a 7-bit hardwired address not selectable by
CA0, CA1 or CA2. If another address is required, please
consult the factory.
The maximum capacitive load allowed on the address pins
(CA0, CA1 and CA2) is 10pF, as these pins are driven during
address detection to determine if they are floating.
CA0
A6
A5
A4
A3
A2
A1
A0
GND
GND
0
0
1
0
0
0
0
GND
FLOAT
0
0
1
0
0
0
1
GND
GND
VCC
0
0
1
0
0
1
0
GND
FLOAT
GND
0
0
1
0
0
1
1
GND
FLOAT FLOAT
0
1
0
0
0
0
0
GND
FLOAT
VCC
0
1
0
0
0
0
1
GND
VCC
GND
0
1
0
0
0
1
0
GND
VCC
FLOAT
0
1
0
0
0
1
1
GND
VCC
VCC
0
1
1
0
0
0
0
FLOAT
GND
GND
0
1
1
0
0
0
1
FLOAT
GND
FLOAT
0
1
1
0
0
1
0
FLOAT
GND
VCC
0
1
1
0
0
1
1
FLOAT
FLOAT
GND
1
0
0
0
0
0
0
FLOAT
FLOAT FLOAT
1
0
0
0
0
0
1
FLOAT
FLOAT
VCC
1
0
0
0
0
1
0
FLOAT
VCC
GND
1
0
0
0
0
1
1
FLOAT
VCC
FLOAT
1
0
1
0
0
0
0
FLOAT
VCC
VCC
1
0
1
0
0
0
1
VCC
GND
GND
1
0
1
0
0
1
0
VCC
GND
FLOAT
1
0
1
0
0
1
1
VCC
GND
VCC
1
1
0
0
0
0
0
VCC
FLOAT
GND
1
1
0
0
0
0
1
VCC
FLOAT FLOAT
1
1
0
0
0
1
0
VCC
FLOAT
VCC
1
1
0
0
0
1
1
VCC
VCC
GND
1
1
1
0
0
0
0
VCC
VCC
FLOAT
1
1
1
0
0
0
1
VCC
VCC
VCC
GLOBAL ADDRESS
1
1
1
0
0
1
0
1
1
1
0
0
1
1
Table 2. Slave Address Map (MSOP Package)
CA0
A6
A5
A4
A3
A2
A1
A0
GND
0
0
1
0
0
0
0
FLOAT
0
0
1
0
0
0
1
VCC
0
0
1
0
0
1
0
GLOBAL ADDRESS
1
1
1
0
0
1
1
2635fb
22
LTC2635
OPERATION
Write Word Protocol
The master initiates communication with the LTC2635
with a START condition and a 7-bit slave address followed
by the Write bit (W) = 0. The LTC2635 acknowledges by
pulling the SDA pin low at the 9th clock if the 7-bit slave
address matches the address of the part (set by CA0, CA1
or CA2) or the global address. The master then transmits
three bytes of data. The LTC2635 acknowledges each byte
of data by pulling the SDA line low at the 9th clock of each
data byte transmission. After receiving three complete
bytes of data, the LTC2635 executes the command specified in the 24-bit input word.
If more than three data bytes are transmitted after a valid
7-bit slave address, the LTC2635 does not acknowledge
(NAK) the extra bytes of data (SDA is high during the 9th
clock).
The format of the three data bytes is shown in Figure 3. The
first byte of the input word consists of the 4-bit command,
followed by the 4-bit DAC address. The next two bytes
contain the 16-bit data word, which consists of the 12-,
10- or 8-bit input code, MSB to LSB, followed by 4, 6 or 8
don’t-care bits (LTC2635-12, -10 and -8, respectively). A
typical LTC2635 write transaction is shown in Figure 4.
The command bit assignments (C3-C0) and address (A3A0) assignments are shown in Tables 3 and 4. The first
four commands in the table consist of write and update
operations. A write operation loads a 16-bit data word
from the 32-bit shift register into the input register. In an
update operation, the data word is copied from the input
register to the DAC register. Once copied into the DAC
register, the data word becomes the active 12-, 10-, or
8-bit input code, and is 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.
Table 3. Command Codes
COMMAND*
C3
C2
C1
C0
0
0
0
0
Write to Input Register n
0
0
0
1
Update (Power Up) DAC Register n
0
0
1
0
Write to Input Register n, Update (Power Up) All
0
0
1
1
Write to and Update (Power Up) DAC Register n
0
1
0
0
Power Down n
0
1
0
1
Power Down Chip (All DAC’s and Reference)
0
1
1
0
Select Internal Reference (Power Up Reference)
0
1
1
1
Select External Reference (Power Down Internal
Reference)
1
1
1
1
No Operation
*Command codes not shown are reserved and should not be used.
Table 4. Address Codes
ADDRESS (n)*
A3
A2
A1
A0
0
0
0
0
DAC A
0
0
0
1
DAC B
0
0
1
0
DAC C
0
0
1
1
DAC D
1
1
1
1
ALL DACs
* Address codes not shown are reserved and should not be used.
Reference Modes
For applications where an accurate external reference is
either not available, or not desirable due to limited space,
the LTC2635 has a user-selectable, integrated reference.
The integrated reference voltage is internally amplified by
2x to provide the full-scale DAC output voltage range. The
LTC2635-LMI/-LMX/-LMO/-LZ provides a full-scale output
of 2.5V. The LTC2635-HMI/-HZ provides 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 0110b,
and is the power-on default for LTC2635-HZ/-LZ, as well
as for LTC2635-HMI/-LMI/-LMO.
2635fb
23
LTC2635
OPERATION
Write Word Protocol for LTC2635
S
W
SLAVE ADDRESS
ACK
1ST DATA BYTE
ACK
2ND DATA BYTE
ACK
3RD DATA BYTE
ACK
P
D1
D0
INPUT WORD
Input Word (LTC2635-12)
C3
C2
C1
C0
A3
A2
A1
A0
D11
D10
D9
1ST DATA BYTE
D8
D7
D6
D5
D4
D3
D2
2ND DATA BYTE
X
X
X
X
X
X
X
X
X
X
3RD DATA BYTE
Input Word (LTC2635-10)
C3
C2
C1
C0
A3
A2
A1
A0
D9
D8
D7
1ST DATA BYTE
D6
D5
D4
D3
D2
D1
D0
X
2ND DATA BYTE
X
X
3RD DATA BYTE
Input Word (LTC2635-8)
C3
C2
C1
C0
A3
A2
A1
A0
D7
D6
D5
1ST DATA BYTE
D4
D3
D2
D1
D0
2ND DATA BYTE
X
X
X
X
X
3RD DATA BYTE
2635 F03
Figure 3. Command and Data Input Format
The 10ppm/°C, 1.25V (LTC2635-LMI/-LMX/-LMO/-LZ) or
2.048V (LTC2635-HMI/-HZ) internal reference is available
at the REF pin. Adding bypass capacitance to the REF pin
will improve noise performance; and up to 10µF can be
driven without oscillation. This output must be buffered
when driving an external DC load current.
Alternatively, the DAC can operate in External Reference
mode using command 0111b. In this mode, an input voltage
supplied externally to the REF pin provides the reference
(1V ≤ VREF ≤ VCC) and the supply current is reduced. The
external reference voltage supplied sets the full-scale DAC
output voltage. External Reference mode is the power-on
default for LTC2635-LMX.
The reference mode of LTC2635-HZ/-LZ/-HMI/-LMI/-LMO
(Internal Reference power-on default), can be changed by
software command after power up. The same is true for
LTC2635-LMX (External Reference power-on default).
Power-Down Mode
For power-constrained applications, power-down mode can
be used to reduce the supply current whenever less than
four DAC outputs are needed. When in power-down, the
buffer amplifiers, bias circuits, and integrated reference
circuits are disabled, and draw essentially zero current.
The DAC amplifier outputs are put into a high-impedance
state, and the output pins are passively pulled to ground
through individual 200k resistors (LTC2635-LMI/-LMX/
-LZ/-HMI/-HZ). For the LTC2635-LMO options, the output pins are not passively pulled to ground, but are also
placed in a high-impedance state (open-circuited state)
during power-down, typically drawing less than 0.1µA.
The LTC2635-LMO options power-up with all DAC outputs
in this high-impedance state. They remain that way until
given a software or hardware update command. For all
LTC2635 options, input- and DAC-register contents are
not disturbed during power-down.
2635fb
24
LTC2635
Operation
Any channel or combination of channels can be put into
power-down mode by using command 0100b in combination with the appropriate DAC address, (n). The supply
current is reduced approximately 20% for each DAC
powered down. The integrated reference is automatically
powered down when external reference is selected using
command 0111b. In addition, all the DAC channels and the
integrated reference together can be put into power-down
mode using Power Down Chip command 0101b. When the
integrated reference is in power-down mode, the REF pin
becomes high impedance (typically > 1GΩ). For all powerdown commands the 16-bit data word is ignored.
Normal operation resumes after executing any command
that includes a DAC update, (as shown in Table 1) or pulling the asynchronous LDAC pin low (QFN package only).
The selected DAC is powered up as its voltage output is
updated. When a DAC which is in a powered-down state
is powered up and updated, normal settling is delayed. If
less than four DACs are in a powered-down state prior to
the update command, the power-up delay time is 10µs.
However, if all four DACs and the integrated reference are
powered down, then the main bias generation circuit block
has been automatically shut down in addition to the DAC
amplifiers and reference buffers. In this case, the power up
delay time is 12µs. The power-up of the integrated reference depends on the command that powered it down. If
the reference is powered down using the Select External
Reference Command (0111b), then it can only be powered
back up using Select Internal Reference Command (0110b).
However, if the reference was powered down using Power
Down Chip Command (0101b), then in addition to Select
Internal Reference Command (0110b), any command (in
software or using the LDAC pin) that powers up the DACs
will also power up the integrated reference.
Voltage Output
The LTC2635’s integrated rail-to-rail amplifier has guaranteed 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 Ω. 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 limited 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 5b.
Similarly, limiting can occur near full-scale when the REF
pin is tied to VCC. If VREF = VCC and the DAC full-scale error
(FSE) is positive, the output for the highest codes limits
at VCC, as shown in Figure 5c. No full-scale limiting can
occur if VREF 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.
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 carefully
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 LTC2635 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 LTC2635 is no more susceptible to
2635fb
25
LTC2635
OPERATION
this effect than any other parts of this type; on the contrary, it allows layout-based performance improvements
to shine rather than limiting attainable performance with
excessive internal resistance.
analog ground, digital ground, and power ground. When
the LTC2635 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.
Another technique for minimizing errors is to use a separate 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
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.
SLAVE ADDRESS
COMMAND/ADDRESS
MS DATA
A6
A5
A4
A3
A2
A1
A0
W
C3
C2
C1 C0
A3
A2
A1
A0
SDA
A6
A5
A4
A3
A2
A1
A0
W ACK C3
C2
C1 C0
A3
A2
A1
A0 ACK
SCL
1
2
3
4
5
6
7
8
2
3
5
6
7
8
LS DATA
D11 D10 D9 D8 D7 D6
D5 D4
D3
D2
D1 D0
X
X
X
X
STOP
START
9
1
4
9
ACK
1
2
3
4
5
6
7
8
9
ACK
1
2
3
4
5
6
VOUT
7
8
9
FULL-SCALE
VOLTAGE
ZERO-SCALE
VOLTAGE
X = DON’T CARE
2635 F04
Figure 4. Typical LTC2635 Input Waveform—Programming DAC Output for Full-Scale
2635fb
26
LTC2635
Operation
VREF = VCC
POSITIVE
FSE
VREF = VCC
OUTPUT
VOLTAGE
OUTPUT
VOLTAGE
INPUT CODE
OUTPUT
VOLTAGE
0V
NEGATIVE
OFFSET
2635 F05
(c)
0
2,048
INPUT CODE
4,095
(a)
0V
INPUT CODE
(b)
Figure 5. Effects of Rail-to-Rail 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
2635fb
27
LTC2635
APPLICATION INFORMATION
Voltage Margining Application with LTC3850 (1.2V ±5%) –LTC2635– LMO Option Only
0.1µF
VIN
6.5V TO 14V
4.7µF
2.2Ω
100k
0.1µF
INTVCC
PGOOD
VIN
ILIM
TG1
10k
0.1µF
BOOST1
FREQ
2.2µH
0.008Ω
VOUT
1.2V ±5%
SW1
1nF
LTC3850EUF
3.32k
BG1
PGND
ITH1
500kHz
1nF
TK/SS1
10k
1nF
RUN1
MODE/PLLIN
100pF
10Ω
SENSE+
10Ω
SENSE–
10nF
VFB1
SGND
15pF
5V
VOUT
1.26V
1.2V
1.14V
DAC D
OUTPUT
0.5V
0.8V
1.1V
DAC CODE
819
1311
1802
7
VCC
REF
0.1µF
63.4k
2635 TA02
20k
1
LTC2635CMSE-LMOI2
2
DAC A
9
DAC D
10k
15k
0.22µF
3
TO I2C
BUS
4
5
6
DAC B
CAO
8
DAC C
GND
10
SCL
SDA
2635 TA02
2635fb
28
LTC2635
Package Description
UD Package
16-Lead Plastic QFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1691)
0.70 p0.05
3.50 p 0.05
1.45 p 0.05
2.10 p 0.05 (4 SIDES)
PACKAGE OUTLINE
0.25 p0.05
0.50 BSC
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
3.00 p 0.10
(4 SIDES)
BOTTOM VIEW—EXPOSED PAD
PIN 1 NOTCH R = 0.20 TYP
OR 0.25 s 45o CHAMFER
R = 0.115
TYP
0.75 p 0.05
15
PIN 1
TOP MARK
(NOTE 6)
16
0.40 p 0.10
1
1.45 p 0.10
(4-SIDES)
2
(UD16) QFN 0904
0.200 REF
0.00 – 0.05
NOTE:
1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WEED-2)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON THE TOP AND BOTTOM OF PACKAGE
0.25 p 0.05
0.50 BSC
2635fb
29
LTC2635
Package Description
MSE Package
10-Lead Plastic MSOP, Exposed Die Pad
(Reference LTC DWG # 05-08-1664 Rev D)
BOTTOM VIEW OF
EXPOSED PAD OPTION
1.88 p 0.102
(.074 p .004)
5.23
(.206)
MIN
0.889 p 0.127
(.035 p .005)
1.68 p 0.102
(.066 p .004)
1
0.05 REF
10
3.00 p 0.102
(.118 p .004)
(NOTE 3)
DETAIL “B”
CORNER TAIL IS PART OF
DETAIL “B” THE LEADFRAME FEATURE.
FOR REFERENCE ONLY
NO MEASUREMENT PURPOSE
10 9 8 7 6
DETAIL “A”
0o – 6o TYP
1 2 3 4 5
GAUGE PLANE
0.53 p 0.152
(.021 p .006)
DETAIL “A”
0.18
(.007)
0.497 p 0.076
(.0196 p .003)
REF
3.00 p 0.102
(.118 p .004)
(NOTE 4)
4.90 p 0.152
(.193 p .006)
0.254
(.010)
0.29
REF
1.68
(.066)
3.20 – 3.45
(.126 – .136)
0.50
0.305 p 0.038
(.0197)
(.0120 p .0015)
BSC
TYP
RECOMMENDED SOLDER PAD LAYOUT
1.88
(.074)
SEATING
PLANE
0.86
(.034)
REF
1.10
(.043)
MAX
0.17 – 0.27
(.007 – .011)
TYP
0.50
(.0197)
BSC
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
6. EXPOSED PAD DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH ON E-PAD
SHALL NOT EXCEED 0.254mm (.010") PER SIDE.
0.1016 p 0.0508
(.004 p .002)
MSOP (MSE) 0210 REV D
2635fb
30
LTC2635
Revision History
REV
DATE
DESCRIPTION
PAGE NUMBER
A
12/09
Revise QFN pin names
2, 17
Minor text edit in Operations section
21, 24
B
06/10
Revised Note 3 in the Electrical Characteristics section
11
Added Typical Application drawing and revised Related Parts List
32
2635fb
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
31
LTC2635
Typical APPLICATION
Voltage Margining Application with LTC3850 (1.2V ±5%) –LTC2635– LMO Option Only
0.1µF
VIN
6.5V TO 14V
4.7µF
2.2Ω
100k
0.1µF
INTVCC
PGOOD
VIN
ILIM
TG1
0.1µF
10k
FREQ
BOOST1
2.2µH
0.008Ω
VOUT
1.2V ±5%
SW1
3.32k
1nF
BG1
LTC3850EUF
PGND
ITH1
SENSE+
MODE/PLLIN
SENSE–
10Ω
RUN1
1nF
10k
500kHz
100pF
TK/SS1
10nF
1nF
10Ω
VFB1
SGND
15pF
5V
7
0.1µF
VOUT
1.26V
1.2V
1.14V
DAC D
OUTPUT
0.5V
0.8V
1.1V
REF
2
DAC CODE
819
1311
1802
LTC2635CMSE-LMOI2
DAC A
VCC
63.4k
1
2635 TA02
9
DAC D
10k
15k
20k
0.22µF
3
TO I2C
BUS
4
5
6
DAC B
CAO
8
DAC C
GND
10
SCL
SDA
2635 TA03
Related Parts
PART NUMBER
LTC2654/LTC2655
DESCRIPTION
Quad 16-/12 Bit, SPI/I2C VOUT DACs with 10ppm/°C
Maximum Reference
LTC2609/LTC2619/ Quad 16-/14-/12-Bit VOUT DACs with I2C Interface
LTC2629
LTC2604/LTC2614/ Quad 16-/14-/12-Bit, SPI VOUT DACs with External
Reference
LTC2624
LTC2634
Quad 12-/10-/8-Bit SPI VOUT DACs with 10ppm/°C
Reference
LTC2656/LTC2657
LTC2636/LTC2637
LTC2630/LTC2631
LTC2640
LTC1664
Octal 16-/12 Bit, SPI/I2C VOUT DACs with 10ppm/°C
Maximum Reference
Octal 12-/10-/8-Bit, SPI/I2C VOUT DACs with
10ppm/°C Reference
Single 12-/10-/8-Bit, SPI/ I2C VOUT DACs with
10ppm/°C Reference
Single 12-/10-/8-Bit, SPI VOUT DACs with 10ppm/°C
Reference
Quad 10-Bit, Serial VOUT DAC
COMMENTS
±4LSB INL Maximum at 16 Bits and ±2mV Offset Error, Rail-to-Rail Output,
20-Lead 4mm × 4mm QFN and 16-Lead Narrow SSOP Packages
250µA per DAC, 2.7V to 5.5V Supply Range, Rail-to-Rail Output with
Separate VREF Pins for Each DAC
250µA per DAC, 2.5V to 5.5V Supply Range, Rail-to-Rail Output, 16-Lead
SSOP Package
125µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference, External
REF Mode, Rail-to-Rail Output, 16-Pin 3mm × 3mm QFN and 10-Lead MSOP
Packages
±4LSB INL Maximum at 16 Bits and ±2mV Offset Error, Rail-to-Rail Output,
20-Lead 4mm × 5mm QFN and 16-Lead TSSOP Packages
125µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference, External
REF Mode, Rail-to-Rail Output, 14-Lead 4mm × 3mm DFN and 16-Lead
MSOP Packages
180µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference,
Rail-to-Rail Output, SC70 (LTC2630)/ThinSOT™ (LTC2631) Packages
180µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference, External
REF Mode, Rail-to-Rail Output, ThinSOT Package
VCC = 2.7V to 5.5V, Micropower, Rail-to-Rail Output, 16-Pin Narrow SSOP
2635fb
32 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
LT 0610 REV B • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 2009
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