Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsData collecting ICsData acquisition IC - DA converter (DAC) SSOP 28

LTC1458/LTC1458L

Quad 12-Bit Rail-to-Rail

Micropower DACs

Daisy-Chained Control Outputs

The LTC

1458/LTC1458L are complete single supply,

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

converters (DACs) in SO-28 and SSOP-28 packages. They

include an output buffer amplifier with variable gain (×1 or

×2) and an easy-to-use 3-wire cascadable serial interface.

The LTC1458 has an onboard reference of 2.048V and a

full-scale output of 4.095V in a ×2 gain configuration. It

operates from a single 4.5V to 5.5V supply dissipating

only 5.5mW (I

= 1.1mA typ).

The LTC1458L has an onboard 1.22V reference and a full-

scale output of 2.5V in a ×2 gain configuration. It operates

from a single supply of 2.7V to 5.5V dissipating 2.4mW.

Excellent DNL, low supply current and a wide range of

built-in functions allow these parts to be used in a host of

applications when flexibility, power and single supply

operation are important.

■

Quad 12-Bit DAC

■

Buffered True Rail-to-Rail Voltage Output

■

Maximum DNL Error: 0.5LSB

■

5V Operation, I

: 1.1mA Typ (LTC1458)

■

3V Operation, I

: 800µA Typ (LTC1458L)

■

Internal or External Reference Operation

■

Settling Time: 14µs to ±0.5LSB

■

Schmitt Trigger On Clock Input Allows Direct

Optocoupler Interface

■

Power-On Reset and CLR Pin

■

SSOP-28 Package

■

3-Wire Cascadable Serial Interface with 250kHz

Update Rate

■

Low Cost

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

Differential Nonlinearity

vs Input Code

■

Digital Calibration

■

Industrial Process Control

■

Automatic Test Equipment

■

Low Power Systems

1458 BD01

48-BIT

SHIFT REGISTER

AND

DAC REGISTER

CLK

5V (LTC1458)

3V TO 5V (LTC1458L)

2.048V (LTC1458)

1.22V (LTC1458L)

REFHI C

REFOUT

OUT C

REFLO C

X1/X2 C

X1/X2 D

X1/X2 A

X1/X2 B

REFHI D

OUT D

REFLO D

REFHI B

FROM µP

OUT B

REFLO B

REFHI A

OUT A

REFLO A

OUT

CS/LD

CLR

DAC D

DAC C

DAC B

DAC A

CODE

DNL (LSB)

0.5

0.4

0.3

0.2

0.1

–0.1

–0.2

–0.3

–0.4

–0.5

1024

2048

2560

1458 G09

512 1536

3072

3584

4095

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO

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

Summary of content (12 pages)

PAGE 1
LTC1458/LTC1458L Quad 12-Bit Rail-to-Rail Micropower DACs U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LTC®1458/LTC1458L are complete single supply, quad rail-to-rail voltage output, 12-bit digital-to-analog converters (DACs) in SO-28 and SSOP-28 packages. They include an output buffer amplifier with variable gain (×1 or × 2) and an easy-to-use 3-wire cascadable serial interface. Quad 12-Bit DAC Buffered True Rail-to-Rail Voltage Output Maximum DNL Error: 0.5LSB 5V Operation, ICC: 1.
PAGE 2
LTC1458/LTC1458L W W W AXI U U ABSOLUTE RATI GS U U W PACKAGE/ORDER I FOR ATIO (Note 1) VCC to GND .............................................. – 0.5V to 7.5V Logic Inputs to GND ................................ – 0.5V to 7.5V VOUT A , VOUT B, VOUT C, VOUT D, X1/X2 A , X1/X2 B, X1/X2 C, X1/X2 D ......................................... – 0.5V to VCC + 0.5V REFHI A , REFHI B, REFHI C, REFHI D, REFLO A , REFLO B, REFLO C, REFLO D ........................................ – 0.5V to VCC + 0.
PAGE 3
LTC1458/LTC1458L ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = TMIN to TMAX. VCC = 4.5V to 5.5V (LTC1458), 2.7V to 5.5V (LTC1458L), X1/X2 = REFLO = GND, REFHI = REFOUT, VOUT unloaded, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP Reference Input Capacitance Short-Circuit Current MAX 15 REFOUT Shorted to GND ● 45 UNITS pF 120 mA 5.5 5.
PAGE 4
LTC1458/LTC1458L ELECTRICAL CHARACTERISTICS Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Nonlinearity is defined from the first code that is greater than or equal to the maximum offset specification to code 4095 (full scale). Note 3: Load is 5kΩ in parallel with 100pF. Note 4: DAC switched between all 1s and the code corresponding to VOS for the part. Note 5: Digital inputs at 0V or VCC.
PAGE 5
LTC1458/LTC1458L U W TYPICAL PERFOR A CE CHARACTERISTICS LTC1458 Full-Scale Voltage vs Temperature OFFSET VOLTAGE (mV) SFULL-SCALE VOLTAGE (V) 4.105 4.100 4.095 4.090 4.085 –25 5 35 65 TEMPERATURE (°C) 95 125 5 950 4 940 3 930 SUPPLY CURRENT (µA) 4.110 4.080 –55 LTC1458 Supply Current vs Temperature LTC1458 Offset Voltage vs Temperature 2 1 0 –1 –2 910 900 880 870 –4 860 –25 35 65 5 TEMPERATURE (°C) 1458 G06 95 125 VCC = 5V 890 –3 –5 –55 VCC = 5.5V 920 850 –55 VCC = 4.
PAGE 6
LTC1458/LTC1458L W BLOCK DIAGRA 28 VCC X1/X2 C 1 LD LD 12-BIT DAC C REGISTER 12-BIT DAC B REGISTER VOUT C 2 CS/LD 3 DIN 4 REFHI C 5 24 REFHI B GND 6 23 GND REFLO C 7 22 REFLO B REFLO D 8 21 REFLO A REFHI D 9 20 REFHI A DAC C DAC B 27 X1/X2 B 26 VOUT B POWER-ON RESET 25 CLR 48-BIT SHIFT REGISTER LTC1458: 2.048V LTC1458L: 1.
PAGE 7
LTC1458/LTC1458L WU W TI I G DIAGRA t9 CLK DIN t2 t6 B11 C MSB B0 D LSB t1 t4 B0 D PREVIOUS WORD t3 B11 A MSB B0 B LSB CS/LD t5 t8 B11 A PREVIOUS WORD DOUT t7 B10 A PREVIOUS WORD B0 B PREVIOUS WORD B11 C PREVIOUS WORD B0 D PREVIOUS WORD B11 A CURRENT WORD 1458 TD 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.
PAGE 8
LTC1458/LTC1458L U U DEFI ITIO S Differential Nonlinearity (DNL): DNL is the difference between the measured change and the ideal 1LSB change between any two adjacent codes. The DNL error between any two codes is calculated as follows: Digital Feedthrough: The glitch that appears at the analog output caused by AC coupling from the digital inputs when they change state. The area of the glitch is specified in (nV)(sec).
PAGE 9
LTC1458/LTC1458L U W U U APPLICATIO S I FOR ATIO Using Two DACs to Digitally Program the Full Scale and Offset of a Third ≤ 2,500 for VCC = 5V, since DAC C is being operated in × 2 mode for full rail-to-rail output swing. Figure 2 shows how to use one LTC1458 to make a 12-bit DAC with a digitally programmable full scale and offset. DAC A and DAC B are used to control the offset and full scale of DAC C.
PAGE 10
LTC1458/LTC1458L U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. G Package 28-Lead Plastic SSOP (0.209) (LTC DWG # 05-08-1640) 10.07 – 10.33* (0.397 – 0.407) 28 27 26 25 24 23 22 21 20 19 18 17 16 15 7.65 – 7.90 (0.301 – 0.311) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 5.20 – 5.38** (0.205 – 0.212) 1.73 – 1.99 (0.068 – 0.078) 0° – 8° 0.13 – 0.22 (0.005 – 0.009) 0.55 – 0.95 (0.022 – 0.037) NOTE: DIMENSIONS ARE IN MILLIMETERS *DIMENSIONS DO NOT INCLUDE MOLD FLASH.
PAGE 11
LTC1458/LTC1458L U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. SW Package 28-Lead Plastic Small Outline (Wide 0.300) (LTC DWG # 05-08-1620) 0.697 – 0.712* (17.70 – 18.08) 28 27 26 25 24 23 22 21 20 19 18 17 16 15 0.394 – 0.419 (10.007 – 10.643) NOTE 1 0.291 – 0.299** (7.391 – 7.595) 1 2 3 4 5 6 7 8 9 10 0.093 – 0.104 (2.362 – 2.642) 0.010 – 0.029 × 45° (0.254 – 0.737) 11 12 13 14 0.037 – 0.045 (0.940 – 1.143) 0° – 8° TYP 0.009 – 0.
PAGE 12
LTC1458/LTC1458L U TYPICAL APPLICATIO VCC X1/X2 C LTC1458: 0V TO 4.095V LTC1458L: 0V TO 2.5V µP VOUT C X1/X2 B CS/LD VOUT B REFHI B REFHI C GND GND REFLO D LTC1458 LTC1458L REFLO B REFLO A REFHI D REFHI A DOUT REFOUT CLK NC LTC1458: 0V TO 4.095V LTC1458L: 0V TO 2.5V LTC1458: 0V TO 4.095V LTC1458L: 0V TO 2.5V CLR DIN REFLO C 0.1µF LTC1458: 4.5V TO 5.5V LTC1458L: 2.7V TO 5.5V VOUT D X1/X2 D LTC1458: 2.048V LTC1458L: 1.22V NC LTC1458: 0V TO 4.095V LTC1458L: 0V TO 2.