LTC2632HTS8-LMI10#TRPBF - LINEAR TECHNOLOGY

LTC2632

2632fa

BLOCK DIAGRAM

FEATURES DESCRIPTION

Dual 12-/10-/8-Bit SPI

VOUT DACs with

10ppm/°C Reference

The LTC

2632 is a family of dual 12-, 10-, and 8-bit voltage-

output DACs with an integrated, high-accuracy, low-drift

reference in an 8-lead TSOT-23 package. It has rail-to-rail

output buffers and is guaranteed monotonic.

The LTC2632-L has a full-scale output of 2.5V, and operates

from a single 2.7V to 5.5V supply. The LTC2632-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 full-scale output to the external

reference voltage.

These DACs communicate via a simple SPI/MICROWIRE

compatible 3-wire serial interface which operates at clock

rates up to 50MHz. The LTC2632 incorporates a power-on

reset circuit. Options are available for reset to zero-scale

or reset to mid-scale in internal reference mode, or reset

to mid-scale in external reference mode after power-up.

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. 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, and 6937178.

Integral Nonlinearity (LTC2632A-LZ12)

APPLICATIONS

n Integrated Precision Reference

2.5V Full-Scale 10ppm/°C (LTC2632-L)

4.096V Full-Scale 10ppm/°C (LTC2632-H)

n Maximum INL Error: ±1LSB (LTC2632A-12)

n Low Noise: 0.75mVP-P 0.1Hz to 200kHz

n Guaranteed Monotonic –40°C to 125°C Automotive

Temperature Range

n Selectable Internal or External Reference

n 2.7V to 5.5V Supply Range (LTC2632-L)

n Low Power Operation 0.4mA at 3V

n Power-On-Reset to Zero-Scale/Mid-Scale

n Double-Buffered Data Latches

n 8-Lead ThinSOT™ Package

n Mobile Communications

n Process Control and Industrial Automation

n Automatic Test Equipment

n Portable Equipment

n Automotive

CODE

INL (LSB)

–1

–2 1024 3072

2632 TA01

40952048

VCC = 3V

INTERNAL REF.

INTERNAL

REFERENCE

POWER-ON

RESET

32-BIT SHIFT REGISTER

CONTROL

LOGIC DECODE

SCK

REF

VREF

2632 BD

CS/LD SDI

VOUTA

VCC

VOUTB

DAC A DAC B

SWITCH

GND

LTC2632

2632fa

PIN CONFIGURATIONABSOLUTE MAXIMUM RATINGS

Supply Voltage (VCC) ................................... –0.3V to 6V

SCK, SDI ...................................................... –0.3V to 6V

CS/LD (Note 11) ............... –0.3V to Min (VCC + 0.3V, 6V)

VOUTA, VOUTB ...................–0.3V to Min (VCC + 0.3V, 6V)

REF ..................................–0.3V to Min (VCC + 0.3V, 6V)

Operating Temperature Range

LTC2632C ................................................ 0°C to 70°C

LTC2632H (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) ...................300°C

(Notes 1, 2)

TOP VIEW

TS8 PACKAGE

8-LEAD PLASTIC TSOT-23

SDI

VCC

VOUTB

VOUTA

SCK

CS/LD

REF

GND

TJMAX = 150°C (NOTE 6), θJA = 195°C/W

LTC2632 A C TS8 –L Z 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

I = Reset to Mid-Scale in Internal Reference Mode

X = Reset to Mid-Scale in External Reference Mode (2632-L Only)

Z = Reset to Zero-Scale in Internal Reference Mode

FULL-SCALE VOLTAGE, INTERNAL REFERENCE MODE

L = 2.5V

H = 4.096V

PACKAGE TYPE

TS8 = 8-Lead Plastic TSOT-23

TEMPERATURE GRADE

C = Commercial Temperature Range (0°C to 70°C)

H = Automotive Temperature Range (–40°C to 125°C)

ELECTRICAL GRADE (OPTIONAL)

A = ±1LSB 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/

ORDER INFORMATION

LTC2632

2632fa

PRODUCT SELECTION GUIDE

PART NUMBER PART MARKING*

VFS WITH INTERNAL

REFERENCE

POWER-ON

RESET TO CODE

POWER-ON

REFERENCE MODE RESOLUTION VCC MAXIMUM INL

LTC2632A-LI12

LTC2632A-LX12

LTC2632A-LZ12

LTC2632A-HI12

LTC2632A-HZ12

LTFSJ

LTFSH

LTFSG

LTFSM

LTFSK

2.5V • (4095/4096)

4.096V • (4095/4096)

Mid-Scale

Zero

Mid-Scale

Zero

Internal

External

Internal

12-Bit

2.7V to 5.5V

4.5V to 5.5V

±1LSB

LTC2632-LI12

LTC2632-LI10

LTC2632-LI8

LTFSJ

LTFSQ

LTFSW

2.5V • (4095/4096)

2.5V • (1023/1024)

2.5V • (255/256)

Mid-Scale

Internal

12-Bit

10-Bit

8-Bit

2.7V to 5.5V

±2.5LSB

±1LSB

±0.5LSB

LTC2632-LX12

LTC2632-LX10

LTC2632-LX8

LTFSH

LTFSP

LTFSV

2.5V • (4095/4096)

2.5V • (1023/1024)

2.5V • (255/256)

Mid-Scale

External

12-Bit

10-Bit

8-Bit

2.7V to 5.5V

±2.5LSB

±1LSB

±0.5LSB

LTC2632-LZ12

LTC2632-LZ10

LTC2632-LZ8

LTFSG

LTFSN

LTFST

2.5V • (4095/4096)

2.5V • (1023/1024)

2.5V • (255/256)

Zero

Internal

12-Bit

10-Bit

8-Bit

2.7V to 5.5V

±2.5LSB

±1LSB

±0.5LSB

LTC2632-HI12

LTC2632-HI10

LTC2632-HI8

LTFSM

LTFSS

LTFSY

4.096V • (4095/4096)

4.096V • (1023/1024)

4.096V • (255/256)

Mid-Scale

Internal

12-Bit

10-Bit

8-Bit

4.5V to 5.5V

±2.5LSB

±1LSB

±0.5LSB

LTC2632-HZ12

LTC2632-HZ10

LTC2632-HZ8

LTFSK

LTFSR

LTFSX

4.096V • (4095/4096)

4.096V • (1023/1024)

4.096V • (255/256)

Zero

Internal

12-Bit

10-Bit

8-Bit

4.5V to 5.5V

±2.5LSB

±1LSB

±0.5LSB

* The temperature grade is identiﬁed by a label on the shipping container.

Above options are available in an 8-lead TSOT package (LTC2632xTS8).

LTC2632

2632fa

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.

LTC2632-LI12/-LI10/-LI8/-LX12/-LX10/-LX8/-LZ12/-LZ10/-LZ8, LTC2632A-LI12/-LX12/-LZ12 (VFS = 2.5V)

SYMBOL PARAMETER CONDITIONS

LTC2632-8 LTC2632-10 LTC2632-12 LTC2632A-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 4)

l8 10 12 12 Bits

DNL Differential

Nonlinearity

VCC = 3V, Internal Ref.

(Note 4)

l±0.5 ±0.5 ±1 ±1 LSB

INL Integral

Nonlinearity

VCC = 3V, Internal Ref.

(Note 4)

l±0.05 ±0.5 ±0.2 ±1 ±1 ±2.5 ±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 5)

l±0.5 ±5 ±0.5 ±5 ±0.5 ±5 ±0.5 ±5 mV

VOSTC VOS

Temperature

Coefﬁcient

VCC = 3V, Internal Ref. ±10 ±10 ±10 ±10 µV/°C

GE Gain Error VCC = 3V, Internal Ref. l0.2 0.8 0.2 0.8 0.2 0.8 0.2 0.8 %FSR

GETC Gain

Temperature

Coefﬁcient

VCC = 3V, Internal Ref.

(Note 10)

C-Grade

H-Grade

ppm/°C

Load

Regulation

Internal Ref., Mid-Scale,

VCC = 3V±10%,

–5mA ≤ IOUT ≤ 5mA

VCC = 5V±10%,

–10mA ≤ IOUT ≤ 10mA

0.009

0.016

0.035

0.064

0.14

0.256

0.14

0.256

LSB/mA

ROUT DC Output

Impedance

Internal Ref., Mid-Scale,

VCC = 3V±10%,

–5mA ≤ IOUT ≤ 5mA

VCC = 5V±10%,

–10mA ≤ IOUT ≤ 10mA

0.09

0.156

0.09

0.156

0.09

0.156

0.09

0.156

Ω

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

VOUT DAC Output Span External Reference

Internal Reference

0 to VREF

0 to 2.5

PSR Power Supply Rejection VCC = 3V±10% or 5V±10% –80 dB

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

–28

–48

Power Supply

VCC Positive Supply Voltage For Speciﬁed Performance l2.7 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

0.3

0.4

0.3

0.4

0.5

0.6

0.5

0.6

ISD Supply Current in Power-Down Mode

(Note 7)

VCC = 5V l0.5 2 µA

LTC2632

2632fa

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.

LTC2632-LI12/-LI10/-LI8/-LX12/-LX10/-LX8/-LZ12/-LZ10/-LZ8, LTC2632A-LI12/-LX12/-LZ12 (VFS = 2.5V)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

Reference Input

Input Voltage Range l1 VCC V

Resistance l120 160 200 kΩ

Capacitance 12 pF

IREF Reference Current, Power-Down Mode DAC Powered Down l0.005 5.0 µA

Reference Output

Output Voltage l1.24 1.25 1.26 V

Reference Temperature Coefﬁcient ±10 ppm/°C

Output Impedance 0.5 kΩ

Capacitive Load Driving 10 µF

Short-Circuit Current VCC = 5.5V, REF Shorted to GND 2.5 mA

Digital I/O

VIH Digital Input High Voltage VCC = 3.6V to 5.5V

VCC = 2.7V to 3.6V

2.4

2.0

VIL Digital Input Low Voltage VCC = 4.5V to 5.5V

VCC = 2.7V to 4.5V

0.8

0.6

ILK Digital Input Leakage VIN = GND to VCC l±1 µA

CIN Digital Input Capacitance (Note 8) l8 pF

AC Performance

tSSettling Time VCC = 3V (Note 9)

±0.39% (±1LSB at 8 Bits)

±0.098% (±1LSB at 10 Bits)

±0.024% (±1LSB at 12 Bits)

3.5

3.9

4.4

µs

Voltage Output Slew Rate 1.0 V/µs

Capacitive Load Driving 500 pF

Glitch Impulse At Mid-Scale Transition 2.8 nV•s

DAC-to-DAC Crosstalk 1 DAC Held at FS, 1 DAC Switch 0 to FS 4.5 nV•s

Multiplying Bandwidth External Reference 320 kHz

enOutput 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

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

680

730

µVP-P

LTC2632

2632fa

LTC2632-LI12/-LI10/-LI8/-LX12/-LX10/-LX8/-LZ12/-LZ10/-LZ8, LTC2632A-LI12/-LX12/-LZ12 (VFS = 2.5V)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

t1SDI Valid to SCK Setup (Figure 1) l4 ns

t2SDI Valid to SCK Hold (Figure 1) l4 ns

t3SCK High Time (Figure 1) l9 ns

t4SCK Low Time (Figure 1) l9 ns

t5CS/LD Pulse Width (Figure 1) l10 ns

t6LSB SCK High to CS/LD High (Figure 1) l7 ns

t7CS/LD Low to SCK High (Figure 1) l7 ns

t10 CS/LD High to SCK Positive Edge (Figure 1) 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, VOUT unloaded unless otherwise speciﬁed.

LTC2632

2632fa

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.

LTC2632-HI12/-HI10/-HI8/-HZ12/-HZ10/-HZ8, LTC2632A-HI12/-HZ12 (VFS = 4.096V)

SYMBOL PARAMETER CONDITIONS

LTC2632-8 LTC2632-10 LTC2632-12 LTC2632A-12

UNITSMIN 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 4) l8 10 12 12 Bits

DNL Differential

Nonlinearity

VCC = 5V, Internal Ref. (Note 4) l±0.5 ±0.5 ±1 ±1 LSB

INL Integral

Nonlinearity

VCC = 5V, Internal Ref. (Note 4) l±0.05 ±0.5 ±0.2 ±1 ±1 ±2.5 ±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 5) l±0.5 ±5 ±0.5 ±5 ±0.5 ±5 ±0.5 ±5 mV

VOSTC VOS

Temperature

Coefﬁcient

VCC = 5V, Internal Ref. ±10 ±10 ±10 ±10 µV/°C

GE Gain Error VCC = 5V, Internal Ref. l0.2 0.8 0.2 0.8 0.2 0.8 0.2 0.8 %FSR

GETC Gain

Temperature

Coefﬁcient

VCC = 5V, Internal Ref. (Note 10)

C-Grade

H-Grade

ppm/°C

Load

Regulation

VCC = 5V±10%, Internal Ref.

Mid-Scale, –10mA ≤ IOUT ≤ 10mA

l0.006 0.01 0.022 0.04 0.09 0.16 0.09 0.16 LSB/

ROUT DC Output

Impedance

VCC = 5V±10%, Internal Ref.

Mid-Scale, –10mA ≤ IOUT ≤ 10mA

l0.09 0.156 0.09 0.156 0.09 0.156 0.09 0.156 Ω

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

VOUT DAC Output Span External Reference

Internal Reference

0 to VREF

0 to 4.096

PSR Power Supply Rejection VCC = 5V±10% –80 dB

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

–28

–48

Power Supply

VCC Positive Supply Voltage For Speciﬁed Performance l4.5 5.5 V

ICC Supply Current (Note 7) VCC = 5V, VREF = 4.096V, External Reference

VCC = 5V, Internal Reference

0.4

0.5

0.6

0.7

ISD Supply Current in Power-Down Mode

(Note 7)

VCC = 5V l0.5 2 µA

LTC2632

2632fa

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.

LTC2632-HI12/-HI10/-HI8/-HZ12/-HZ10/-HZ8, LTC2632A-HI12/-HZ12 (VFS = 4.096V)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

Reference Input

Input Voltage Range l1 VCC V

Resistance l120 160 200 kΩ

Capacitance 12 pF

IREF Reference Current, Power-Down Mode DAC Powered Down l0.005 5.0 µA

Reference Output

Output Voltage l2.032 2.048 2.064 V

Reference Temperature Coefﬁcient ±10 ppm/°C

Output Impedance 0.5 kΩ

Capacitive Load Driving 10 µF

Short-Circuit Current VCC = 5.5V; REF Shorted to GND 4 mA

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 8) l8 pF

AC Performance

tSSettling Time VCC = 5V (Note 9)

±0.39% (±1LSB at 8 Bits)

±0.098% (±1LSB at 10 Bits)

±0.024% (±1LSB at 12 Bits)

3.9

4.1

4.9

µs

Voltage Output Slew Rate 1.0 V/µs

Capacitive Load Driving 500 pF

Glitch Impulse At Mid-Scale Transition 3.0 nV•s

DAC-to-DAC Crosstalk 1 DAC Held at FS, 1 DAC Switch 0 to FS 6.7 nV•s

Multiplying Bandwidth External Reference 320 kHz

enOutput 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

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

680

750

µVP-P

LTC2632

2632fa

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, VOUT unloaded unless otherwise speciﬁed.

LTC2632-HI12/-HI10/-HI8/-HZ12/-HZ10/-HZ8, LTC2632A-HI12/-HZ12 (VFS = 4.096V)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

t1SDI Valid to SCK Setup (Figure 1) l4 ns

t2SDI Valid to SCK Hold (Figure 1) l4 ns

t3SCK High Time (Figure 1) l9 ns

t4SCK Low Time (Figure 1) l9 ns

t5CS/LD Pulse Width (Figure 1) l10 ns

t6LSB SCK High to CS/LD High (Figure 1) l7 ns

t7CS/LD Low to SCK High (Figure 1) l7 ns

t10 CS/LD High to SCK Positive Edge (Figure 1) l7 ns

SCK Frequency 50% Duty Cycle l50 MHz

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.

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 5: Inferred from measurement at code 16 (LTC2632-12), code 4

(LTC2632-10) or code 1 (LTC2632-8), 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.

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: CS/LD can be held at high voltage as VCC ramps upon power-up.

LTC2632

2632fa

TYPICAL PERFORMANCE CHARACTERISTICS

INL vs Temperature DNL vs Temperature

Reference Output Voltage

vs Temperature

Settling to ±1LSB Rising Settling to ±1LSB Falling

Integral Nonlinearity (INL) Differential Nonlinearity (DNL)

TA = 25°C, unless otherwise noted. LTC2632-L12 (Internal Reference, VFS = 2.5V)

CODE

INL (LSB)

1.0

0.5

–0.5

–1.0 1024 3072

2632 G01

40952048

VCC = 3V

CODE

DNL (LSB)

1.0

0.5

–0.5

–1.0 1024 3072

2632 G02

40952048

VCC = 3V

2µs/DIV

CS/LD

5V/DIV

VOUT

1LSB/DIV

2632 G06

1/4 SCALE TO

3/4 SCALE STEP

VCC = 3V,

VFS = 2.5V

RL = 2k,

CL = 100pF

AVERAGE OF

256 EVENTS

3.3µs

2µs/DIV

CS/LD

5V/DIV

VOUT

1LSB/DIV

2632 G07

4.4µs

3/4 SCALE TO

1/4 SCALE STEP

VCC = 3V,

VFS = 2.5V

RL = 2k,

CL = 100pF

AVERAGE OF

256 EVENTS

TEMPERATURE (°C)

–50

INL (LSB)

1.0

0.5

–0.5

–1.0 –25 125100755025

2632 G03

1500

VCC = 3V

INL (POS)

INL (NEG)

TEMPERATURE (°C)

–50

DNL (LSB)

1.0

0.5

–0.5

–1.0 –25 125100755025

2632 G04

1500

VCC = 3V

DNL (POS)

DNL (NEG)

TEMPERATURE (°C)

–50

VREF (V)

1.260

1.255

1.250

1.245

1.240 –25 125100755025

2632 G05

1500

VCC = 3V

LTC2632

2632fa

TYPICAL PERFORMANCE CHARACTERISTICS

TA = 25°C, unless otherwise noted. LTC2632-H12 (Internal Reference, VFS = 4.096V)

INL vs Temperature DNL vs Temperature

Reference Output Voltage

vs Temperature

Settling to ±1LSB Rising Settling to ±1LSB Falling

Integral Nonlinearity (INL) Differential Nonlinearity (DNL)

CODE

INL (LSB)

1.0

0.5

–0.5

–1.0 1024 3072

2632 G08

40952048

VCC = 5V

CODE

DNL (LSB)

1.0

0.5

–0.5

–1.0 1024 3072

2632 G09

40952048

VCC = 5V

2µs/DIV

CS/LD

5V/DIV

VOUT

1LSB/DIV

2632 G13

4.1µs

1/4 SCALE TO

3/4 SCALE STEP

VCC = 3V,

VFS = 4.095V

RL = 2k,

CL = 100pF

AVERAGE OF

256 EVENTS

2µs/DIV

CS/LD

5V/DIV

VOUT

1LSB/DIV

2632 G14

4.9µs

3/4 SCALE TO

1/4 SCALE STEP

VCC = 5V,

VFS = 4.095V

RL = 2k,

CL = 100pF

AVERAGE OF

256 EVENTS

TEMPERATURE (°C)

–50

INL (LSB)

1.0

0.5

–0.5

–1.0 –25 125100755025

2632 G10

1500

VCC = 5V

INL (POS)

INL (NEG)

TEMPERATURE (°C)

–50

DNL (LSB)

1.0

0.5

–0.5

–1.0 –25 125100755025

2632 G11

1500

VCC = 5V

DNL (POS)

DNL (NEG)

TEMPERATURE (°C)

–50

VREF (V)

2.068

2.058

2.048

2.038

2.028 –25 125100755025

2632 G12

1500

VCC = 5V

LTC2632

2632fa

Integral Nonlinearity (INL) Differential Nonlinearity (DNL)

Load Regulation Current Limiting Offset Error vs Temperature

Integral Nonlinearity (INL) Differential Nonlinearity (DNL)

TA = 25°C, unless otherwise noted.

TYPICAL PERFORMANCE CHARACTERISTICS

LTC2632-10

LTC2632-8

LTC2632

CODE

INL (LSB)

1.0

0.5

–0.5

–1.0 256 768

2632 G15

1023512

VCC = 3V

VFS = 2.5V

INTERNAL REF

CODE

DNL (LSB)

1.0

0.5

–0.5

–1.0 256 768

2632 G16

1023512

VCC = 3V

VFS = 2.5V

INTERNAL REF

CODE

INL (LSB)

0.50

0.25

–0.25

–0.50 64 192

2632 G17

255128

VCC = 3V

VFS = 2.5V

INTERNAL REF

CODE

DNL (LSB)

0.50

0.25

–0.25

–0.50 64 192

2632 G18

255128

VCC = 3V

VFS = 2.5V

INTERNAL REF

IOUT (mA)

–30

∆VOUT (mV)

–4

–2

–8

–6

–10 –20 –10 20

2632 G19

30100

INTERNAL REFERENCE

CODE = MID-SCALE

VCC = 5V (LTC2632-H)

VCC = 5V (LTC2632-L)

VCC = 3V (LTC2632-L)

IOUT (mA)

–30

∆VOUT (V)

0.20

0.15

0.05

0.10

–0.05

–0.15

–0.10

–0.20 –20 –10 20

2632 G20

30100

INTERNAL REFERENCE

CODE = MID-SCALE

VCC = 5V (LTC2632-H)

VCC = 5V (LTC2632-L)

VCC = 3V (LTC2632-L)

TEMPERATURE (°C)

–50

OFFSET ERROR (mV)

–1

–2

–3 –25 125100755025

2632 G21

1500

LTC2632

2632fa

Headroom at Rails

vs Output Current Exiting Power-Down to Mid-Scale

Power-On Reset to Mid-Scale Supply Current vs Logic Voltage

Large-Signal Response Mid-Scale Glitch Impulse Power-On Reset Glitch

TA = 25°C, unless otherwise noted.

TYPICAL PERFORMANCE CHARACTERISTICS

LTC2632

2µs/DIV

VOUT

0.5V/DIV

2632 G22

VFS = VCC = 5V

1/4 SCALE to 3/4 SCALE

2µs/DIV

CS/LD

5V/DIV

VOUT

2mV/DIV

2632 G23

LTC2632-H12, VCC = 5V

3.0nV-s TYP

LTC2632-L12, VCC = 3V

2.8nV-s TYP

200µs/DIV

VOUT

10mV/DIV

VCC

2V/DIV

2632 G24

LTC2632-L

ZERO-SCALE

IOUT (mA)

VOUT (V)

5.0

4.0

3.0

4.5

3.5

2.5

1.5

2.0

0.5

1.0

021 3 8

2632 G25

106 974 5

5V SOURCING

5V SINKING

3V (LTC2632-L) SOURCING

3V (LTC2632-L) SINKING

5µs/DIV

VOUTA

0.5V/DIV

CS/LD

5V/DIV

2632 G26

LTC2632-H

VCC = 5V

INTERNAL REF

DAC B IN

POWER-DOWN

MODE

200µs/DIV

VOUT

0.5V/DIV

VCC

2V/DIV

2632 G27

LTC2632-H

LTC2632-L

LOGIC VOLTAGE (V)

ICC (mA)

1.2

1.0

0.8

0.4

0.6

0.2 21 4

2632 G28

VCC = 3V

(LTC2632-L)

VCC = 5V

SWEEP SCK, SDI, CS/LD

BETWEEN

0V AND VCC

LTC2632

2632fa

TA = 25°C, unless otherwise noted.

LTC2632

TYPICAL PERFORMANCE CHARACTERISTICS

Gain Error vs Reference Input 0.1Hz to 10Hz Voltage Noise

DAC to DAC Crosstalk (Dynamic) Gain Error vs Temperature

Multiplying Bandwidth Noise Voltage vs Frequency

FREQUENCY (Hz)

–2

–6

–4

–8

–12

–10

–16

–14

–18 100k

2632 G29

1M10k

VCC = 5V

VREF(DC) = 2V

VREF(AC) = 0.2VP-P

CODE = FULL-SCALE

REFERENCE VOLTAGE (V)

1 2.52

GAIN ERROR (%FSR)

0.8

0.4

0.6

0.2

–0.4

–0.6

–0.2

–0.8 4.5

2632 G31

5.53.51.5 4 53

VCC = 5.5V

GAIN ERROR OF 2 CHANNELS

1s/DIV

10µV/DIV

2632 G32

VCC = 5V, VFS = 2.5V

CODE = MID-SCALE

INTERNAL REFERENCE

2µs/DIV

VOUT

2mV/DIV

1 DAC

SWITCH 0-FS

2V/DIV

CS/LD

5V/DIV

2632 G33

LTC2632-H12, VCC = 5V

6.7nV-s TYP

TEMPERATURE (°C)

–50

GAIN ERROR (%FSR)

1.0

0.5

–0.5

–1.0 –25 125100755025

2634 G34

1500

FREQUENCY (Hz)

100 1k

NOISE VOLTAGE (nV/√Hz)

500

300

400

100

200

0100k

2632 G30

1M10k

VCC = 5V

CODE = MID-SCALE

INTERNAL REFERENCE

LTC2632-H

LTC2632-L

LTC2632

2632fa

PIN FUNCTIONS

SCK (Pin 1): Serial Interface Clock Input. CMOS and TTL

compatible.

CS/LD (Pin 2): 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.

REF (Pin 3): 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 (LTC2632-L) or 2.048V (LTC2632-H)

internal reference (half full-scale) is available at the pin.

This output may be bypassed to GND with up to 10µF

(0.1µF is recommended) and must be buffered when

driving external DC load current.

GND (Pin 4): Ground.

VOUT A, VOUT B (Pins 5, 6): DAC Analog Voltage Output.

VCC (Pin 7): Supply Voltage Input. 2.7V ≤ VCC ≤ 5.5V

(LTC2632-L) or 4.5V ≤ VCC ≤ 5.5V (LTC2632-H). Bypass

to GND with a 0.1µF capacitor.

SDI (Pin 8): Serial Interface Data Input. Data on SDI is

clocked into the DAC on the rising edge of SCK. The LTC2632

accepts input word lengths of either 24 or 32 bits.

LTC2632

2632fa

BLOCK DIAGRAM

TIMING DIAGRAM

INTERNAL

REFERENCE

POWER-ON

RESET

32-BIT SHIFT REGISTER

CONTROL

LOGIC DECODE

SCK

REF

VREF

2632 BD

CS/LD SDI

VOUTA

VCC

VOUTB

DAC A DAC B

SWITCH

GND

SDI

CS/LD

SCK

t10

t5t7

t3t4

1 2 3 23 24

2632 F01

Figure 1. Serial Interface Timing

LTC2632

2632fa

OPERATION

The LTC2632 is a family of dual voltage output DACs in an

8-lead TSOT package. Each DAC can operate rail-to-rail

using an external reference, or with its full-scale voltage

set by an integrated reference. Fifteen 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), and full-scale voltage (2.5V

or 4.096V) are available. The LTC2632 is controlled using

a 3-wire SPI/MICROWIRE compatible interface.

Power-On Reset

The LTC2632-HZ/LTC2632-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 LTC2632 con-

tains circuitry to reduce the power-on glitch: the analog

output typically rises less than 10mV above zero-scale

during 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 LTC2632-HI/LTC2632-LI/LTC2632-LX provides an

alternative reset, setting the output to mid-scale when

power is ﬁrst applied. The LTC2632-LI and LTC2632-HI

power-up in internal reference mode, with the output set

to a mid-scale voltage of 1.25V and 2.048V respectively.

The LTC2632-LX powers up in external reference mode,

with the output set to mid-scale of the external reference.

Default reference mode selection is described in the Refer-

ence Modes section.

Power Supply Sequencing

The voltage at REF (Pin 3) must be kept within the range

–0.3V ≤ VREF ≤ VCC + 0.3V (see the Absolute Maximum

Ratings section). Particular care should be taken to observe

these limits during power supply turn-on and turn-off

sequences, when the voltage at VCC is in transition.

Transfer Function

The digital-to-analog transfer function is

VOUT(IDEAL) =k











•VREF

where k is the decimal equivalent of the binary DAC input

code, N is the resolution, and VREF is either 2.5V (LTC2632-

LI/LTC2632-LX/LTC2632-LZ) or 4.096V (LTC2632-HI/

LTC2632-HZ) when in internal reference mode, and the

voltage at REF when in external reference mode.

Table 1. 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 2. Address Codes

ADDRESS (n)*

A3 A2 A1 A0

0 0 0 0 DAC A

0 0 0 1 DAC B

1 1 1 1 All DACs

* Address codes not shown are reserved and should not be used.

LTC2632

2632fa

OPERATION

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 the 4-bit

DAC address, A3-A0; and ﬁnally the 16-bit data word.

The data word comprises the 12-, 10- or 8-bit input code,

ordered MSB-to-LSB, followed by 4, 6 or 8 don’t-care bits

(LTC2632-12, LTC2632-10 and LTC2632-8 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.

The command (C3-C0) and address (A3-A0) assignments

are shown in Tables 1 and 2. The ﬁrst four commands in

Table 1 consist of write and update operation. A Write

operation loads a 16-bit data word from the 24-bit shift

Update operation copies the data word from the input

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.

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 trans-

ferred 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.

2632 F02

C3 C2 C1 C0

COMMAND

INPUT WORD (LTC2632-12)

INPUT WORD (LTC2632-10)

A3 A2 A1 A0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X

ADDRESS DATA (12 BITS + 4 DON’T-CARE BITS)

C3 C2 C1 C0

COMMAND

A3 A2 A1 A0 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X X X

ADDRESS DATA (10 BITS + 6 DON’T-CARE BITS)

C3 C2 C1 C0

COMMAND

A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 XX X X X X X X

ADDRESS

MSB LSB

DATA (8 BITS + 8 DON’T-CARE BITS)

INPUT WORD (LTC2632-8)

Figure 2. Command and Data Input Format

LTC2632

2632fa

OPERATION

Reference Modes

For applications where an accurate external reference is not

available, nor desirable due to limited space, the LTC2632

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 LTC2632-LI/

LTC2632-LX/LTC2632-LZ provides a full-scale output of

2.5V. The LTC2632-HI/LTC2632-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 com-

mand 0110b, and is the power-on default for LTC2632-HZ/

LTC2632-LZ, as well as for LTC2632-HI/LTC2632-LI.

The 10ppm/°C, 1.25V (LTC2632-LI/LTC2632-LX/LTC2632-

LZ) or 2.048V (LTC2632-HI/LTC2632-HZ) internal reference

is available at the REF pin. Adding bypass capacitance

to the REF pin will improve noise performance; 0.1µF

is recommended, 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 the LTC2632-LX.

The reference mode of LTC2632-HZ/LTC2632-LZ/LTC2632-

HI/LTC2632-LI (internal reference power-on default),

can be changed by software command after power-up.

The same is true for the LTC2632-LX (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

two 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 outputs are put into a high-impedance state, and

the output pins are passively pulled to ground through

individual 200k resistors. Input and DAC-register contents

are not disturbed during power-down.

Either channel or both 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 30% 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 refer-

ence 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 power-down

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). The se-

lected 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

two DACs are in a powered-down state prior to the update

command, the power-up delay time is 10µs. However, if

both DACs and the integrated reference are powered down,

then the main bias generation circuit block has been auto-

matically 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 com-

mand (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 the select internal

reference command (0110b), any command that powers

up the DACs will also power-up the integrated reference.

LTC2632

2632fa

Voltage Output

The LTC2632’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 Charac-

teristics 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 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 4c. 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.

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 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 LTC2632 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 LTC2632 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 LTC2632 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.

Bypass capacitors should be placed as close to the pins

as possible with a low impedance path to GND.

LTC2632

2632fa

OPERATION

Figure 3a. LTC2632-12 24-Bit Load Sequence (Minimum Input Word)

LTC2632-10 SDI Data Word: 10-Bit Input Code + 6 Don’t-Care Bits;

LTC2632-8 SDI Data Word: 8-Bit Input Code + 8 Don’t-Care Bits

Figure 3b. LTC2632-12 32-Bit Load Sequence

LTC2632-10 SDI Data Word: 10-Bit Input Code + 6 Don’t-Care Bits;

LTC2632-8 SDI Data Word: 8-Bit Input Code + 8 Don’t-Care Bits

2632 F03a

C3 C2 C1 C0

COMMAND WORD

A3 A2 A1 A0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X

ADDRESS DATA WORD

SDI

SCK

CS/LD

18 19 20 21 22 23 241 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

24-BIT INPUT WORD

2632 F03b

C3 C2 C1 C0

COMMAND WORD

A3 A2 A1 A0

X X X X X X XX D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X

8 DON’T CARE BITS ADDRESS DATA WORD

SDI

SCK

CS/LD

18 19 20 21 22 23 241 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 26 27 28 29 30 31 3225

32-BIT INPUT WORD

LTC2632

2632fa

OPERATION

2632 F04

INPUT CODE

(b)

OUTPUT

VOLTAGE

NEGATIVE

OFFSET

0V 2,0480 4,095

INPUT CODE

OUTPUT

VOLTAGE

(a)

VREF = VCC

(c)

INPUT CODE

OUTPUT

VOLTAGE

POSITIVE

FSE

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

PACKAGE DESCRIPTION

TS8 Package

8-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1637 Rev A)

1.50 – 1.75

(NOTE 4)

2.80 BSC

0.22 – 0.36

8 PLCS (NOTE 3)

DATUM ‘A’

0.09 – 0.20

(NOTE 3)

TS8 TSOT-23 0710 REV A

2.90 BSC

(NOTE 4)

0.65 BSC

1.95 BSC

0.80 – 0.90

1.00 MAX 0.01 – 0.10

0.20 BSC

0.30 – 0.50 REF

PIN ONE ID

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. JEDEC PACKAGE REFERENCE IS MO-193

3.85 MAX

0.40

MAX

0.65

REF

RECOMMENDED SOLDER PAD LAYOUT

PER IPC CALCULATOR

1.4 MIN

2.62 REF

1.22 REF

LTC2632

2632fa

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

A 3/11 Revised part numbering 2 to 9, 17, 19,

LTC2632

2632fa

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com

 LINEAR TECHNOLOGY CORPORATION 2011

LT 0311 REV A • PRINTED IN USA

TYPICAL APPLICATION

PART NUMBER DESCRIPTION COMMENTS

LTC1662 Dual 10-Bit Ultralow Power VOUT DAC in 8-Lead MSOP

with External Reference

1.5µA per DAC, 2.7V 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

with External Reference

300µA per DAC, 2.5V to 5.5V Supply Range, Rail-to-Rail Output,

SPI Serial Interface

LTC2607/LTC2617/

LTC2627

Dual 16-/14-/12-Bit VOUT DACs in 12-Lead DFN

with External Reference

260µA per DAC, 2.7V to 5.5V Supply Range, Rail-to-Rail Output,

I2C Serial Interface

LTC2630 Single 12-/10-/8-Bit VOUT DACs with 10ppm/°C Reference

in SC70

180µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference,

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,

External REF Mode, Rail-to-Rail Output, I2C Interface

LTC2634 Quad 12-/10-/8-Bit VOUT DACs with 10ppm/°C Reference 125µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference,

External REF Mode, Rail-to-Rail Output, SPI Interface

LTC2636 Octal 12-/10-/8-Bit VOUT DACs with 10ppm/°C Reference 125µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference,

External REF Mode, Rail-to-Rail Output, SPI Interface

LTC2640 Single 12-/10-/8-Bit VOUT DACs with 10ppm/°C Reference

in ThinSOT

180µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference,

External REF Mode, Rail-to-Rail Output, SPI Interface

LTC2654 Quad 16-/12-Bit VOUT DACs with ±4 LSB INL, ±1 LSB DNL 4mm × 4mm QFN-20, SSOP-16 Packages, SPI Interface,

Internal 10ppm/°C (Max) Reference

RELATED PARTS

LTC2632 DACs Adjust LTC2755-16 Offset, Ampliﬁed with LT1991 PGA to ±5V

–

DAC A

DAC D

LTC2755

RCOM1

RIN1

OUTA

–15V

15V

ROFSA

RFBA

RVOSA

GND

IOUT1A

IOUT2A

VDD

REFA

–

1/2 LT1469 1/2 LT1469

15V

–15V

DAC C

–15V

30k

LT1634-1.25

SERIAL

BUS

DAC A

CS/LD

SCK

2632 TA02

0.1µF

GND

LTC2632TS8-LI12

REF

VCC

SDI

DAC B

M1 OUT VOUT

±6V

LT1991

REF

VEE

VCC

0.1µF

10V

–10V

DAC B

–

0.1µF

LT6240

0.1µF

0.1µF 30pF

30pF

0.1µF