Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsData collecting ICsData acquisition IC - DA converter (DAC) LTC 1451 CS 8 SOIC 8

LTC1451

LTC1452/LTC1453

12-Bit Rail-to-Rail

Micropower DACs in SO-8

Daisy-Chained Control Outputs



CLK

CS/LD

OUT



CLK

CS/LD

OUT

µP

0.1µF

CONTROL

OUTPUT 1

CONTROL

OUTPUT 2

OUT

GND

LTC1451

REF

TO NEXT DAC

0.1µF

1451/2/3 TA01

Differential Nonlinearity

vs Input Code

TYPICAL APPLICATION

CODE

DNL ERROR (LSB)

0.5

0.0

–0.5

1024 2048 2560

1451/2/3 TA02

512 1536 3072 3584

4095

■

Digital Calibration

■

Industrial Process Control

■

Automatic Test Equipment

■

Cellular Telephones

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

APPLICATIONS

FEATURES

■

12-Bit Resolution

■

Buffered True Rail-to-Rail Voltage Output

■

3V Operation (LTC1453), I

: 250µA Typ

■

5V Operation (LTC1451), I

: 400µA Typ

■

3V to 5V Operation (LTC1452), I

: 225µA Typ

■

Built-In Reference: 2.048V (LTC1451)

1.220V (LTC1453)

■

Multiplying Version (LTC1452)

■

Power-On Reset

■

SO-8 Package

■

3-Wire Cascadable Serial Interface

■

Maximum DNL Error: 0.5LSB

■

Low Cost

The LTC

1451/LTC1452/LTC1453 are complete single

supply, rail-to-rail voltage output 12-bit digital-to-analog

converters (DACs) in an SO-8 package. They include an

output buffer amplifier and an easy-to-use 3-wire

cascadable serial interface.

The LTC1451 has an onboard reference of 2.048V and a

full-scale output of 4.095V. It operates from a single 4.5V

to 5.5V supply.

The LTC1452 is a multiplying DAC with a full-scale output

of twice the reference input voltage. It operates from a

single supply of 2.7V to 5.5V.

The LTC1453 has an onboard 1.22V reference and a full-

scale output of 2.5V. It operates from a single supply of

2.7V to 5.5V.

The low power supply current makes the LTC1451 family

ideal for battery-powered applications. The space saving

8-pin SO package and operation with no external compo-

nents provide the smallest 12-bit DAC system available.

DESCRIPTION

Summary of content (12 pages)

PAGE 1
LTC1451 LTC1452/LTC1453 12-Bit Rail-to-Rail Micropower DACs in SO-8 U DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 12-Bit Resolution Buffered True Rail-to-Rail Voltage Output 3V Operation (LTC1453), ICC: 250µA Typ 5V Operation (LTC1451), ICC: 400µA Typ 3V to 5V Operation (LTC1452), ICC: 225µA Typ Built-In Reference: 2.048V (LTC1451) 1.220V (LTC1453) Multiplying Version (LTC1452) Power-On Reset SO-8 Package 3-Wire Cascadable Serial Interface Maximum DNL Error: 0.
PAGE 2
LTC1451 LTC1452/LTC1453 W W U W ABSOLUTE MAXIMUM RATINGS VCC to GND .............................................. – 0.5V to 7.5V TTL Input Voltage .................................... – 0.5V to 7.5V VOUT .............................................. – 0.5V to VCC + 0.5V REF ................................................ – 0.5V to VCC + 0.5V Maximum Junction Temperature ......... – 65°C to 125°C Operating Temperature Range Commercial ...........................................
PAGE 3
LTC1451 LTC1452/LTC1453 ELECTRICAL CHARACTERISTICS VCC = 4.5V to 5.5V (LTC1451), 2.7V to 5.5V (LTC1452/LTC1453), internal or external reference (VREF ≤ VCC /2), VOUT and REF unloaded, TA = TMIN to TMAX, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS 2.008 1.195 2.048 1.220 2.088 1.245 V V Reference (LTC1451/LTC1453) Reference Output Voltage LTC1451 LTC1453 ● ● ±0.08 Reference Output Temperature Coefficient Reference Line Regulation ● 0.7 ±2 0.2 0.6 ± 1.
PAGE 4
LTC1451 LTC1452/LTC1453 ELECTRICAL CHARACTERISTICS VCC = 5V (LTC1451LTC1452), VCC = 3V (LTC1453), TA = TMIN to TMAX SYMBOL PARAMETER CONDITIONS LTC1451/LTC1452 MIN TYP MAX MIN 2.4 2.0 LTC1453 TYP MAX UNITS Digital I/O VIH Digital Input High Voltage ● VIL Digital Input Low Voltage ● 0.8 0.6 V VOH Digital Output High Voltage IOUT = – 1mA ● VCC – 1.0 VCC – 0.
PAGE 5
LTC1451 LTC1452/LTC1453 U W TYPICAL PERFORMANCE CHARACTERISTICS LTC1451 Supply Current vs Logic Input Voltage 4.0 FULL SCALE RL TIED TO GND 3.5 0.95 OUTPUT SWING (V) SUPPLY CURRENT (mA) 1000 4.5 ALL DIGITAL INPUTS TIED TOGETHER 0.85 0.75 0.65 3.0 2.5 VCC = 5V 2.0 1.5 0.55 1.0 0.45 ZERO SCALE RL TIED TO VCC 0.5 OUTPUT PULL-DOWN VOLTAGE (mV) 1.15 1.05 LTC1451 Pull-Down Voltage vs Output Sink Current Capability LTC1451 Output Swing vs Load Resistance 0 0.35 0 0.5 1.0 1.5 2.0 2.5 3.0 3.
PAGE 6
LTC1451 LTC1452/LTC1453 U U U PIN FUNCTIONS CLK: The TTL Level Input for the Serial Interface Clock. GND: Ground. DIN: The TTL Level Input for the Serial Interface Data. Data on the DIN pin is latched into the shift register on the rising edge of the serial clock. REF: The Output of the Internal Reference and the Input to the DAC Resistor Ladder. An external reference with voltage up to VCC /2 may be used for the LTC1452. CS/LD: The TTL Level Input for the Serial Interface Enable and Load Control.
PAGE 7
LTC1451 LTC1452/LTC1453 U U DEFI ITIO S Resolution (n): Resolution is defined as the number of digital input bits, n. It defines the number of DAC output states (2n) that divide the full-scale range. The resolution does not imply linearity. Full-Scale Voltage (VFS): This is the output of the DAC when all bits are set to 1. Voltage Offset Error (VOS): The theoretical voltage at the output when the DAC is loaded with all zeros.
PAGE 8
LTC1451 LTC1452/LTC1453 U OPERATIO Serial Interface Reference The data on the DIN input is loaded into the shift register on the rising edge of the clock. The MSB is loaded first. The DAC register loads the data from the shift register when CS/LD is pulled high. The CLK is disabled internally when CS/LD is high. Note: CLK must be low before CS/LD is pulled low to avoid an extra internal clock pulse. The LTC1451 includes an internal 2.048V reference, making 1LSB equal to 1mV (gain of 2).
PAGE 9
LTC1451 LTC1452/LTC1453 UO TYPICAL APPLICATI S An Isolated 4mA to 20mA Process Controller Has 3.3V Minimum Loop Voltage VLOOP 3.3V TO 30V LT ®1121-3.3 IN 90k 5k 45k 5k OUT 1µF CLK FROM OPTOISOLATED INPUTS VCC DIN VREF LTC1453 VOUT CS/LD + LT1077 3k – 1k Q1 2N3440 RS 10Ω IOUT 11451/2/3 TA04 3.3V OPTO-ISOLATORS CLK DIN CS/LD 500Ω 10k 4N28 CLK DIN CS/LD This circuit shows how to use an LTC1453 to make an opto-isolated digitally controlled 4mA to 20mA process controller.
PAGE 10
LTC1451 LTC1452/LTC1453 UO TYPICAL APPLICATI S 12-Bit 3V to 5V Voltage Output DAC LTC1451: 4.5V TO 5.5V LTC1452: 2.7V TO 5.5V LTC1453: 2.7V TO 5.5V 0.1µF DIN VCC CLK µP VOUT LTC145X CS/LD DOUT VREF TO NEXT DAC FOR DAISY-CHAINING GND OUTPUT LTC1451: 0V TO 4.095V LTC1452: 0V TO 2 • REF LTC1453: 0V TO 2.5V 1451/2/3 TA03 LTC1451: 2.048V LTC1452: EXTERNAL LTC1453: 1.22V Digitally Programmable Current Source 5V VS + 5V TO 100V FOR RL ≤ 50Ω 0.
PAGE 11
LTC1451 LTC1452/LTC1453 UO TYPICAL APPLICATI S A Wide Swing, Bipolar Output 12-Bit DAC 5V 0.1µF VCC CLK µP VOUT LTC1451 DIN CS/LD GND R1 5k VREF 5V + R2 10k 4.094 VOUT 2048 4095 R3 10k DIN LT1077 VOUT: 2 • DIN • 4.095 – 4.096V 4096 – – 5V R4 20k 1451/2/3 TA06 – 4.096 R5 20k This circuit shows how to make a bipolar output 12-bit DAC with a wide output swing using an LTC1451 and an LT ® 1077.
PAGE 12
LTC1451 LTC1452/LTC1453 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. N8 Package 8-Lead Plastic DIP 0.300 – 0.325 (7.620 – 8.255) 0.009 – 0.015 (0.229 – 0.381) ( +0.025 0.325 –0.015 +0.635 8.255 –0.381 ) 0.400* (10.160) MAX 0.130 ± 0.005 (3.302 ± 0.127) 0.045 – 0.065 (1.143 – 1.651) 0.065 (1.651) TYP 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.125 (3.175) MIN 0.005 (0.127) MIN 0.015 (0.380) MIN N8 0695 0.018 ± 0.003 (0.457 ± 0.076) 0.100 ± 0.