LTC2654 Linear Technology, LTC2654 Datasheet
LTC2654
Available stocks
Related parts for LTC2654
LTC2654 Summary of contents
Page 1
... These DACs communicate via a SPI/MICROWIRE compat- ible 4-wire serial interface which operates at clock rates up to 50MHz. The LTC2654 incorporates a power-on reset circuit that is controlled by the PORSEL pin. If PORSEL is tied to GND the DACs reset to zero-scale. If PORSEL is tied the DACs reset to mid-scale ...
Page 2
... CC CS/LD, SCK, SDI, LDAC, CLR, REFLO .......... –0. ............................–0.3V to Min (V OUTA-D REFIN/OUT, REFCOMP .....–0.3V to Min (V PORSEL, SDO ..................–0.3V to Min (V Operating Temperature Range LTC2654C ................................................ 0°C to 70°C LTC2654I..............................................–40°C to 85°C PIN CONFIGURATION TOP VIEW REFLO OUTA REFCOMP ...
Page 3
... PACKAGE TYPE UF = 20-Lead (4mm × 4mm) Plastic QFN GN = 16-Lead Narrow SSOP TEMPERATURE GRADE C = Commercial Temperature Range (0°C to 70° Industrial Temperature Range (–40°C to 85°C) ELECTRICAL GRADE (OPTIONAL ±4LSB INL (MAX) PRODUCT PART NUMBER http://www.linear.com/leadfree/ http://www.linear.com/tapeandreel/ www.DataSheet4U.com LTC2654 2654f 3 ...
Page 4
... Consult LTC Marketing for information on non-standard lead based fi nish parts. For more information on lead free part marking, go to: For more information on tape and reel specifi cations, go to: ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T LTC2654B-L16/LTC2654-L12 (Internal Reference = 1.25V) SYMBOL PARAMETER CONDITIONS DC Performance Resolution ...
Page 5
... PSR Power Supply Rejection R DC Output Impedance OUT DC Crosstalk I Short-Circuit Output Current SC LTC2654B-L16/ LTC2654-L12 (Internal Reference = 1.25V) SYMBOL PARAMETER Reference Reference Output Voltage Reference Temperature Coeffi cient Reference Line Regulation Reference Short-Circuit Current Refcomp Pin Short-Circuit Current Reference Load Regulation ...
Page 6
... LTC2654 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T LTC2654B-L16/ LTC2654-L12 (Internal Reference = 1.25V) SYMBOL PARAMETER I Digital Input Leakage LK C Digital Input Capacitance IN AC Performance t Settling Time S Settling Time for 1LSB Step Voltage Output Slew Rate Capacitive Load Driving ...
Page 7
... ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER DC Crosstalk I Short-Circuit Output Current SC LTC2654B-H16/ LTC2654-H12 (Internal Reference = 2.048V) SYMBOL PARAMETER Reference Reference Output Voltage Reference Temperature Coeffi cient Reference Line Regulation Reference Short-Circuit Current Refcomp Pin Short-Circuit Current ...
Page 8
... N = 16, k REF defi ned from code 128 to code 65535. For V REF and linearity is defi ned from code 8 to code 4,095. Note 4: Inferred from measurement at code 128 (LTC2654-16), or code 8 (LTC2654-12). Note 5: DC Crosstalk is measured with and using internal CC reference, with the measured DAC at mid-scale. ...
Page 9
... G04 Sampling to ±1LSB Falling V OUT 200μV/DIV 8μs CS/LD 3V/DIV 2654 G06 3/4 SCALE TO 1/4 SCALE STEP AVERAGE OF 2048 EVENTS www.DataSheet4U.com LTC2654 INL vs Temperature INL (POS –1 INL (NEG) –2 –3 –4 65535 –50 – ...
Page 10
... LTC2654 TYPICAL PERFORMANCE CHARACTERISTICS LTC2654-H16 Integral Nonlinearity (INL –1 –2 –3 –4 128 16384 32768 49152 65535 CODE 2654 G08 DNL vs Temperature 1 0.5 DNL (POS) 0 DNL (NEG) –0.5 –1.0 –50 –30 – TEMPERATURE (°C) Settling to ±1LSB Rising ...
Page 11
... V OUT 1mV/DIV 4095 2μs/DIV 1/4 SCALE TO 3/4 SCALE STEP 2654 G16 4.095V 2k AVERAGE OF 2048 EVENTS Headroom at Rails vs Output Current 5.0 5V (LTC2654-H) SOURCING 4.5 4.0 3.5 3V (LTC2654-L) SOURCING 3.0 2.5 2.0 1.5 5V (LTC2654-H) SINKING 1.0 0.5 3V (LTC2654-H) SINKING (mA) OUT 2654 G19 Gain Error vs Temperature ...
Page 12
... OFFSET ERROR OF 4 CHANNELS 1.5 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 0.5 1 1.5 2 REFERENCE VOLTAGE (V) 2654 G24 Supply Current vs Logic Voltage 3.5 SWEEP SCK, SDI, CS/LD BETWEEN 0V AND V CC 3.1 2.7 2 (LTC2654- (LTC2654- LOGIC VOLTAGE (V) 2654 G27 Multiplying Bandwidth –2 –4 –6 V ...
Page 13
... REFCOMP = 0.22μF V OUT 2mV/DIV 2μs/DIV Power-On Reset to Mid-Scale LTC2654 2V/DIV V OUT 1V/DIV 1ms/DIV DAC Output 0.1Hz to 10Hz Voltage Noise V = 5V, LTC2654-H CC CODE = MID-SCALE INTERNAL REF 0.1μF REFCOMP REFOUT 5μV/DIV 1s/DIV Power-On Reset Glitch V CC 2V/DIV V OUT = 5V CC ...
Page 14
... SDI (Pin 9/Pin 9): Serial Interface Data Input. Data is ap- plied to SDI for transfer to the device at the rising edge of SCK (Pin 10). The LTC2654 accepts input word lengths of either bits. See Figures 2a and 2b. SDO (Pin 10/Pin 10): Serial Interface Data Output. This pin is used for daisy-chain operation ...
Page 15
... SDO LDAC INTERNAL REFERENCE CONTROL LOGIC DECODE 32-BIT SHIFT REGISTER Figure 1a CS/ LDAC Figure 1b www.DataSheet4U.com LTC2654 REFIN/OUT OUTD DAC D V OUTC DAC C PORSEL POWER-ON RESET SDO SDI CLR 2636 ...
Page 16
... LTC2654 OPERATION The LTC2654 is a family of quad voltage output DACs in 20-lead 4mm × 4mm QFN and in 16-lead narrow SSOP packages. Each DAC can operate rail-to-rail in external reference mode, or with its full-scale voltage set by an integrated reference. Four combinations of accuracy (16- bit and 12-bit), and full-scale voltage (2 ...
Page 17
... MSB-to-LSB followed by four don’t-care bits. Data can only be transferred to the LTC2654 when the CS/LD signal is low. The rising edge of CS/LD ends the data transfer and causes the device to carry out the action specifi the 24-bit input word ...
Page 18
... LTC2654 OPERATION 18 www.DataSheet4U.com 2654f ...
Page 19
... For applications where an accurate external reference is not available, the LTC2654 has a user-selectable, inte- grated reference. The LTC2654-L has a 1.25V reference that provides a full-scale output of 2.5V. The LTC2654-H has a 2.048V reference that provides a full-scale output of 4.096V. Both references exhibit a typical temperature drift of 2ppm/°C. Internal reference mode can be selected by using command 0110b, and is the power-on default ...
Page 20
... LTC2654 OPERATION Integrated Reference Buffers Each of the four DACs in the LTC2654 has its own inte- grated high performance reference buffer. The buffers have very high input impedance and do not load the reference voltage source. These buffers shield the reference voltage from glitches caused by DAC switching and thus minimize DAC-to-DAC Dynamic Crosstalk. Typically DAC-to-DAC crosstalk is less than 3nV• ...
Page 21
... OPERATION www.DataSheet4U.com LTC2654 2654f 21 ...
Page 22
... LTC2654 PACKAGE DESCRIPTION .254 MIN .0165 ± .0015 RECOMMENDED SOLDER PAD LAYOUT .007 – .0098 (0.178 – 0.249) .016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) 3. DRAWING NOT TO SCALE *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" ...
Page 23
... Plastic QFN (4mm × 4mm) (Reference LTC DWG # 05-08-1710) 0.70 ±0.05 PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC 0.115 0.75 ± 0.05 TYP 2.00 REF 0.200 REF 0.00 – 0.05 www.DataSheet4U.com LTC2654 PIN 1 NOTCH R = 0.20 TYP BOTTOM VIEW—EXPOSED PAD OR 0.35 × 45° CHAMFER TYP 19 20 0.40 ± 0. 2.45 ± 0.10 2.45 ± 0.10 (UF20) QFN 01-07 REV A 0.25 ± ...
Page 24
... True Rail-to-Rail Output DAC 0.1μF 0.1μF C1 0.1μ REFIN/OUT LDAC PORSEL CLR V REFCOMP CC 6 CS/LD 7 SCK 9 LTC2654 SDI 10 SDO GND GND REFLO DNC DNC DNC COMMENTS V = 2.7V to 5.5V, Micropower, Rail-to-Rail Output 2.7V to 5.5V, Micropower, Rail-to-Rail Output CC Parallel Interface, Precision 16-Bit Settling in 2μ ...