Linear Technology LTC1446, LTC1446L Datasheet

LTC1446/LTC1446L

Dual 12-Bit Rail-to-Rail

Micropower DACs in SO-8

EATU

F

■

Dual DACs with 12-Bit Resolution

■

SO-8 Package

■

Rail-to-Rail Output Amplifiers

■

3V Operation (LTC1446L): ICC = 650µA Typ

■

5V Operation (LTC1446): ICC = 1000µA Typ

■

Internal Reference

■

Power-On Reset Clears DACs to 0V

■

3-Wire Cascadable Serial Interface

■

Maximum DNL Error: 0.5LSB

■

Low Cost

■

Schmitt Trigger On Input Allows Direct

RE

S

Optocoupler Interface

U

O

PPLICATI

A

■

Digital Calibration

■

Industrial Process Control

■

Automatic Test Equipment

■

Cellular Telephones

S

DUESCRIPTIO

The LTC®1446/LTC1446L are dual 12-bit digital-to-analog converters (DACs) available in an SO-8 package. They are complete with a rail-to-rail voltage internal reference and an easy-to-use 3-wire cascadable serial interface.

The LTC1446 has an internal reference and a full-scale output of 4.095V. It operates from a single 4.5V to 5.5V supply.

The LTC1446L has an internal reference and a full-scale output of 2.5V. It operates from a single 2.7V to 5.5V supply.

The low power supply current makes the LTC1446 family ideal for battery-powered applications. These DACs are available in space saving 8-pin SO and PDIP packages and require no external components for operation.

, LTC and LT are registered trademarks of Linear Technology Corporation.

output amplifier, an

U

O

A

PPLICATITYPICAL

Functional Block Diagram: Dual 12-Bit Rail-to-Rail DAC

LTC1446: 5V LTC1446L: 3V TO 5V

7

V

CC

DIN2

µP

CLK1

24-BIT

SHIFT

CS/LD3

REG AND DAC

LATCH

4

D

OUT

POWER-ON

RESET

12-BIT DAC B

12-BIT DAC A

GND

6

+

–

+

–

V

OUT B

V

OUT A

1446/1446L TA01

8

RAIL-TO-RAIL VOLTAGE OUTPUT

5

Differential Nonlinearity vs Input Code

0.5

0.4

0.3

0.2

0.1 0

–0.1

DNL ERROR (LSB)

–0.2 –0.3 –0.4 –0.5

1024 2048 2560

512 1536 3072 3584 4095

0

CODE

1446/46L G13

1

LTC1446/LTC1446L

A

W

O

LUTEXI T

S

A

WUW

ARB

U

G

I

S

VCC to GND................................................ –0.5 to 7.5V

Logic Inputs to GND................................... –0.5 to 7.5V

Operating Temperature Range

LTC1446C/LTC1446LC............................0°C to 70°C

LTC1446I/LTC1446LI ..........................–40°C to 85°C

U

W

PACKAGE/ORDER INFORMATION

ORDER PART

TOP VIEW

1

CLK

D



2

IN

CS/LD

3

D

4

OUT

N8 PACKAGE 8-LEAD PDIP

T

= 125°C, θJA = 100°C/W

JMAX

Consult factory for Military grade parts.

V

8

OUT B

V



7

CC

GND

6

V

5

OUT A



NUMBER

LTC1446CN8 LTC1446IN8 LTC1446LCN8 LTC1446LIN8

V

OUT A/VOUT B

.................................–0.5V to VCC + 0.5V

Maximum Junction Temperature..........................125°C

Storage Temperature Range ..................–65°C to 150°C

Lead Temperature (Soldering, 10 sec)................. 300°C

U

ORDER PART

NUMBER

LTC1446CS8 LTC1446IS8 LTC1446LCS8 LTC1446LIS8

S8 PART MARKING

1446C 1446LC 1446I 1446LI

1

CLK

D



2

IN

CS/LD

3

D

4

OUT

8-LEAD PLASTIC SO

= 125°C, θJA = 150°C/W

T

JMAX

TOP VIEW

S8 PACKAGE



V

8

OUT B

V



7

CC

GND

6

V

5

OUT A

ELECTRICAL CHARACTERISTICS

VCC = 4.5V to 5.5V (LTC1446), 2.7V to 5.5V (LTC1446L), V

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS DAC

Resolution ● 12 Bits DNL Differential Nonlinearity Guaranteed Monotonic (Note 1) ● ±0.2 ±0.5 LSB INL Integral Nonlinearity TA = 25°C ±2.0 4.5 LSB

ZSE Zero-Scale Error ● 0 3 18 mV V

OS

V

TC Offset Error Tempco ±15 µV/°C

OS

V

FS

V

TC Full-Scale Voltage Tempco ±0.1 LSB/°C

FS

Power Supply (LTC1446)

V

CC

I

CC

Power Supply (LTC1446L)

V

CC

I

CC

Offset Error ● ±2 ±18 mV

Full-Scale Voltage LTC1446, TA = 25°C 4.065 4.095 4.125 V

LTC1446 ● 4.045 4.095 4.145 V LTC1446L, T LTC1446L ● 2.460 2.500 2.540 V

Positive Supply Voltage For Specified Performance ● 4.5 5.5 V

Supply Current 4.5V ≤ V

Positive Supply Voltage For Specified Performance ● 2.7 5.5 V

Supply Current 2.7V ≤ V

and V

OUT A

= 25°C 2.470 2.500 2.530 V

A

≤ 5.5V (Note 4) ● 1000 1500 µA

CC

≤ 5.5V (Note 4) ● 650 1000 µA

CC

unloaded, TA = T

OUT B

to T

MIN

● ±2.5 5.0 LSB

unless otherwise noted.

MAX,

2

LTC1446/LTC1446L

ELECTRICAL CHARACTERISTICS

VCC = 4.5V to 5.5V (LTC1446), 2.7V to 5.5V (LTC1446L), V

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Op Amp DC Performance

Short-Circuit Current Low V

Short-Circuit Current High V

Output Impedance to GND Input Code = 0 ● 40 120 Ω

AC Performance

Voltage Output Slew Rate (Note 2) ● 0.5 1 V/µs

Voltage Output Settling Time (Notes 2, 3) to ±0.5LSB 14 µs

OUT OUT

and V

OUT A

Shorted to GND ● 55 120 mA Shorted to V

unloaded, TA = T

OUT B

CC

to T

MIN

● 70 120 mA

unless otherwise noted.

MAX,

VCC = 5V (LTC1446), VCC = 3V (LTC1446L), TA = T

SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS Digital I/O

V

IH

V

IL

V

OH

V

OL

I

LEAK

C

IN

Switching

t

1

t

2

t

3

t

4

t

5

t

6

t

7

t

8

t

9

Digital Input High Voltage ● 2.4 2 V Digital Input Low Voltage ● 0.8 0.6 V Digital Output High Voltage I Digital Output Low Voltage I Digital Input Leakage VIN = GND to V Digital Input Capacitance Guaranteed by Design ● 10 10 pF

DIN Valid to CLK Setup ● 40 60 ns DIN Valid to CLK Hold ● 00ns CLK High Time ● 40 60 ns CLK Low Time ● 40 60 ns CS/LD Pulse Width ● 50 80 ns LSB CLK to CS/LD ● 40 60 ns CS/LD Low to CLK ● 20 30 ns D

Output Delay C

OUT

CLK Low to CS/LD Low ● 20 30 ns

= –1mA ● VCC – 1.0 VCC – 0.7 V

OUT

= 1mA ● 0.4 0.4 V

OUT

= 15pF ● 150 220 ns

LOAD

MIN

to T

CC

unless otherwise noted.

MAX,

LTC1446 LTC1446L

● ±10 ±10 µA

The

● denotes specifications which apply over the full operating

temperature range. Note 1: Nonlinearity is defined from the first code that is greater

than or equal to the maximum offset specification to code 4095 (full scale).

Note 2: Load is 5kΩ in parallel with 100pF. Note 3: DAC switched between all 1s and the code corresponding

to VOS for the part. Note 4: Digital inputs at 0V or VCC.

3

LTC1446/LTC1446L

CODE

0

–0.5

DNL ERROR (LSB)

–0.4

–0.2

–0.1

0

0.5

0.2

1024 2048 2560

1446/46L G03

–0.3

0.3

0.4

0.1

512 1536 3072 3584 4095

LOAD CURRENT (mA)

0

V

CC

– V

OUT

0.2

0.4

0.6

0.8

1.2

510

LTC1446/46L • TPC06

15

1.0

∆V

OUT

< 1LSB CODE: ALL 1's V

OUT

= 2.5V

LOGIC INPUT VOLTAGE (V)

0.6

SUPPLY CURRENT (mA)

1.4

2.2

3.0

1.0

1.8

2.6

1234

1446/46L G09

50

W

U

TYPICAL PERFORMANCE CHARACTERISTICS

LTC1446 Differential Nonlinearity (DNL) LTC1446 Integral Nonlinearity (INL) LTC1446L Differential Nonlinearity

0.5

0.4

0.3

0.2

0.1 0

–0.1

DNL ERROR (LSB)

–0.2 –0.3 –0.4 –0.5

1024 2048 2560

512 1536 3072 3584 4095

0

CODE

1446/46L G01

3

2

1

0

–1

INL ERROR (LSB)

–2

–3

512 1536

0

1024 2048

CODE

2560

3072

3584

1446/46L G02

4095

LTC1446L Integral Nonlinearity

3

2

1

0

–1

INL ERROR (LSB)

–2

–3

512 1536

0

1024 2048

LTC1446 Min Output Voltage vs Output Sink Current

600

CODE: ALL 0'S

500

400

300

200

100

OUTPUT PULL-DOWN VOLTAGE (mV)

0

OUTPUT SINK CURRENT (mA)

4

3072

2560

CODE

125°C

510

25°C

–55°C

LTC1446/46L • TPC07

3584

1446/46L G04

4095

15

LTC1446 Min Supply Headroom for Full Output Swing vs Load Current

0.8 ∆V

< 1LSB

OUT

CODE: ALL 1's

= 4.095V

V

OUT

0.6

(V)

OUT

0.4

– V

CC

V

0.2

0

5

LOAD CURRENT (mA)

10

LTC1446 Full-Scale Voltage vs Temperature

4.11

4.10

4.09

4.08

FULL-SCALE VOLTAGE (V)

4.07 –55

–25 5 35 65

TEMPERATURE (°C)

LTC1446L Min Supply Headroom for Full Output Swing vs Load Current

15

LTC1446/46L • TPC05

LTC1446 Supply Current vs Logic Input Voltage

95 125

1446/46L G09

Linear Technology LTC1446, LTC1446L Datasheet

Specifications and Main Features

Frequently Asked Questions

User Manual