LTC2634HUD-HZ8#PBF

LTC2634 Quad 12-/10-/8-Bit Rail-to-Rail DACs with 10ppm/°C Reference FEATURES DESCRIPTION AEC-Q100 Qualified for Automotive Applications n Integrated Precision Reference 2.5V Full-Scale 10ppm/°C (LTC2634-L) 4.096V Full-Scale 10ppm/°C (LTC2634-H) n Maximum INL Error: ±2.5 LSB (LTC2634-12) n Low Noise: 0.75mV P-P 0.1Hz to 200KHz n Guaranteed Monotonic over −40°C to 125°C Temperature Range n Selectable Internal or External Reference n 2.7V to 5.5V Supply Range (LTC2634-L) n Ultralow Crosstalk Between DACs (2.4nV•s) n Low Power: 0.6mA at 3V n Power-On Reset to Zero-Scale/Mid-Scale n Double Buffered Data Latches n Tiny 16-Lead 3mm × 3mm QFN and 10-Lead MSOP Packages The LTC®2634 is a family of quad 12-, 10- and 8-bit voltage output DACs with an integrated, high accuracy, low drift 10ppm/°C reference in 16-lead QFN and 10-lead MSOP packages. It has rail-to-rail output buffers and is guaranteed monotonic. The LTC2634-L has a full-scale output of 2.5V, and operates from a single 2.7V to 5.5V supply. The LTC2634-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. n These DACs communicate via an SPI/MICROWIRE compatible 3-wire serial interface which operates at clock rates up to 50MHz. Serial data output (SDO), a hardware clear (CLR), and an asynchronous DAC update (LDAC) capability are available in the QFN package. The LTC2634 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. APPLICATIONS Mobile Communications Process Control and Industrial Automation n Automatic Test Equipment n Portable Equipment n Automotive n All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 5396245, 5859606, 6891433, 6937178, 7414561. n BLOCK DIAGRAM INTERNAL REFERENCE GND SWITCH REF Integral Nonlinearity (LTC2634-LZ12) VREF VCC REGISTER REGISTER DAC A REGISTER 2 DAC D REGISTER REGISTER REGISTER DAC B REGISTER VOUTB 1 VREF VREF DAC C VOUTC SDI CS/LD CONTROL LOGIC 0 –1 DECODE –2 SCK (LDAC) VCC = 3V INTERNAL REF VOUTD INL (LSB) VOUTA REGISTER (REFLO) 32-BIT SHIFT REGISTER POWER-ON RESET (CLR) 0 1024 2048 3072 4095 CODE (SDO) 2634 TA01 2634 BD ( ) QFN PACKAGE ONLY Rev E Document Feedback For more information www.analog.com 1 LTC2634 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) Supply Voltage (VCC).................................... –0.3V to 6V CS/LD, SCK, SDI, LDAC, CLR, SDO, REFLO... –0.3V to 6V VOUTA-VOUTD.....................–0.3V to Min (VCC + 0.3V, 6V) REF...................................–0.3V to Min (VCC + 0.3V, 6V) Operating Temperature Range LTC2634C................................................. 0°C to 70°C LTC2634I..............................................–40°C to 85°C LTC2634H (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) MSOP................................................................ 300°C PIN CONFIGURATION REFLO GND DNC VCC TOP VIEW TOP VIEW 16 15 14 13 VOUTA 1 12 VOUTD VOUTB 2 11 VOUTC 17 LDAC 3 VCC VOUTA VOUTB CS/LD SCK 10 REF CS/LD 4 6 7 8 SCK DNC SDO SDI 9 5 CLR UD PACKAGE 16-LEAD (3mm × 3mm) PLASTIC QFN TJMAX = 125°C, θJA = 68°C/W EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB 1 2 3 4 5 11 10 9 8 7 6 GND VOUTD VOUTC REF SDI MSE PACKAGE 10-LEAD PLASTIC MSOP TJMAX = 125°C, θJA = 35°C/W EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB Rev E 2 For more information www.analog.com LTC2634 ORDER INFORMATION LTC2634 C UD -L Z 12 #W TR PBF LEAD FREE DESIGNATOR PBF = Lead Free TAPE AND REEL TR = 2,500-Piece Tape and Reel AUTOMOTIVE (AEC-Q100) (8-Bit and 10-Bit) RESOLUTION 12 = 12-Bit 10 = 10-Bit 8 = 8-Bit POWER-ON RESET MI = Reset to Mid-Scale in Internal Reference Mode MX = Reset to Mid-Scale in External Reference Mode Z = Reset to Zero-Scale in Internal Reference Mode FULL-SCALE VOLTAGE, INTERNAL REFERENCE MODE L = 2.5V H = 4.096V PACKAGE TYPE UD = 16-Lead QFN MSE = 10-Lead MSOP TEMPERATURE GRADE C = Commercial Temperature Range (0°C to 70°C) I = Industrial Temperature Range (–40°C to 85°C) H = Automotive Temperature Range (–40°C to 125°C) PRODUCT PART NUMBER Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix. **Versions of this part are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. These models are designated with a #W suffix. Only the automotive grade products shown are available for use in automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for these models. Rev E For more information www.analog.com 3 LTC2634 PRODUCT SELECTION GUIDE PART MARKING* VFS WITH INTERNAL POWER-ON REFERENCE RESET TO CODE POWER-ON REFERENCE MODE PART NUMBER QFN MSOP RESOLUTION VCC MAXIMUM INL LTC2634-LMI12 LTC2634-LMI10 LTC2634-LMI8 LDQX LDRF LDRN LTDRV LTDSC LTDSK 2.5V • (4095/4096) 2.5V • (1023/1024) 2.5V • (255/256) Mid-Scale Mid-Scale Mid-Scale Internal Internal Internal 12-Bit 10-Bit 8-Bit 2.7V to 5.5V 2.7V to 5.5V 2.7V to 5.5V ±2.5LSB ±1LSB ±0.5LSB LTC2634-LMX12 LTC2634-LMX10 LTC2634-LMX8 LDQW LDRD LDRM LTDRT LTDSB LTDSJ 2.5V • (4095/4096) 2.5V • (1023/1024) 2.5V • (255/256) Mid-Scale Mid-Scale Mid-Scale External External External 12-Bit 10-Bit 8-Bit 2.7V to 5.5V 2.7V to 5.5V 2.7V to 5.5V ±2.5LSB ±1LSB ±0.5LSB LTC2634-LZ12 LTC2634-LZ10 LTC2634-LZ8 LDQV LDRC LDRK LTDRS LTDRZ LTDSH 2.5V • (4095/4096) 2.5V • (1023/1024) 2.5V • (255/256) Zero-Scale Zero-Scale Zero-Scale Internal Internal Internal 12-Bit 10-Bit 8-Bit 2.7V to 5.5V 2.7V to 5.5V 2.7V to 5.5V ±2.5LSB ±1LSB ±0.5LSB LTC2634-HMI12 LTC2634-HMI10 LTC2634-HMI8 LDRB LDRJ LDRR LTDRY LTDSG LTDSP 4.096V • (4095/4096) 4.096V • (1023/1024) 4.096V • (255/256) Mid-Scale Mid-Scale Mid-Scale Internal Internal Internal 12-Bit 10-Bit 8-Bit 4.5V to 5.5V 4.5V to 5.5V 4.5V to 5.5V ±2.5LSB ±1LSB ±0.5LSB LTC2634-HMX12 LTC2634-HMX10 LTC2634-HMX8 LDQZ LDRH LDRQ LTDRX LTDSF LTDSN 4.096V • (4095/4096) 4.096V • (1023/1024) 4.096V • (255/256) Mid-Scale Mid-Scale Mid-Scale External External External 12-Bit 10-Bit 8-Bit 4.5V to 5.5V 4.5V to 5.5V 4.5V to 5.5V ±2.5LSB ±1LSB ±0.5LSB LTC2634-HZ12 LTC2634-HZ10 LTC2634-HZ8 LDQY LDRG LDRP LTDRW 4.096V • (4095/4096) LTDSD 4.096V • (1023/1024) LTDSM 4.096V • (255/256) Zero-Scale Zero-Scale Zero-Scale Internal Internal Internal 12-Bit 10-Bit 8-Bit 4.5V to 5.5V 4.5V to 5.5V 4.5V to 5.5V ±2.5LSB ±1LSB ±0.5LSB *Above options are available in a 16-lead QFN package (LTC2634-UD) or 10-lead MSOP package (LTC2634-MSE). Rev E 4 For more information www.analog.com LTC2634 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. LTC2634-LMI12/-LMI10/-LMI8/-LMX12/-LMX10/-LMX8/-LZ12/-LZ10/-LZ8 (VFS = 2.5V) SYMBOL PARAMETER LTC2634-8 LTC2634-10 LTC2634-12 MIN TYP MAX MIN TYP MAX MIN TYP MAX CONDITIONS UNITS DC Performance Resolution DNL l 8 8 10 Monotonicity VCC = 3V, Internal Ref. (Note 4) l Differential Nonlinearity VCC = 3V, Internal Ref. (Note 4) l ±0.5 ±0.05 ±0.5 12 10 Bits 12 Bits ±0.5 ±1 LSB INL Integral Nonlinearity VCC = 3V, Internal Ref. (Note 4) l ±0.2 ±1 ±1 ±2.5 LSB ZSE Zero-Scale Error VCC = 3V, Internal Ref., Code = 0 l 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 mV VOSTC VOS Temperature Coefficient VCC = 3V, Internal Ref. GE Gain Error VCC = 3V, Internal Ref. GETC Gain Temperature Coefficient VCC = 3V, Internal Ref. (Note 10) C-Grade I-Grade H-Grade Load Regulation Internal Ref., Mid-Scale VCC = 3V ±10%, –5mA ≤ IOUT ≤ 5mA l 0.009 0.016 0.035 0.064 0.14 0.256 LSB/ mA Internal Ref., Mid-Scale VCC = 5V ±10%, –10mA ≤ IOUT ≤ 10mA l 0.009 0.016 0.035 0.064 0.14 0.256 LSB/ mA Internal Ref., Mid-Scale VCC = 3V ±10%, –5mA ≤ IOUT ≤ 5mA l 0.09 0.156 0.09 0.156 0.09 0.156 Ω Internal Ref., Mid-Scale VCC = 5V ±10%, –10mA ≤ IOUT ≤ 10mA l 0.09 0.156 0.09 0.156 0.09 0.156 Ω ROUT DC Output Impedance l SYMBOL PARAMETER CONDITIONS VOUT DAC Output Span External Reference Internal Reference ±10 ±10 ±10 µV/°C ±0.2 ±0.8 ±0.2 ±0.8 ±0.2 ±0.8 %FSR 10 10 10 10 10 10 MIN PSR Power Supply Rejection VCC = 3V ±10% or 5V ±10% 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 l l 10 10 10 TYP ppm/°C ppm/°C ppm/°C MAX UNITS 0 to VREF 0 to 2.5 V V –80 dB 27 –27 48 –48 mA mA 5.5 V Power Supply VCC Positive Supply Voltage For Specified Performance l 2.7 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 l l l l 0.5 0.6 0.6 0.7 0.7 0.8 0.8 0.9 mA mA mA mA ISD Supply Current in Power-Down Mode (Note 7) VCC = 5V, C-Grade, I-Grade VCC = 5V, H-Grade l l 0.5 0.5 20 30 µA µA Rev E For more information www.analog.com 5 LTC2634 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. LTC2634-LMI12/-LMI10/-LMI8/-LMX12/-LMX10/-LMX8/-LZ12/-LZ10/-LZ8 (VFS = 2.5V) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VCC V 160 200 kΩ 0.005 1.5 µA 1.25 1.26 Reference Input VREF Input Voltage Range l 1 Resistance l 120 Capacitance IREF Reference Current, Power-Down Mode 14 DAC Powered Down l pF Reference Output Output Voltage l 1.24 V Reference Temperature Coefficient ±10 ppm/°C Output Impedance 0.5 kΩ Capacitive Load Driving 10 µF 2.5 mA Short-Circuit Current VCC = 5.5V, REF Shorted to GND VIH Digital Input High Voltage VCC = 3.6V to 5.5V VCC = 2.7V to 3.6V l l VIL Digital Input Low Voltage VCC = 4.5V to 5.5V VCC = 2.7V to 4.5V l l VOH Digital Output High Voltage Load Current = –100µA l VOL Digital Output Low Voltage Load Current = 100µA l ILK Digital Input Leakage VIN = GND to VCC CIN Digital Input Capacitance (Note 8) Digital I/O 2.4 2.0 V V 0.8 0.6 V V 0.4 V l ±1 µA l 2.5 pF VCC – 0.4 V AC Performance tS en Settling Time VCC = 3V (Note 9) ±0.39% (±1LSB at 8 Bits) ±0.098% (±1LSB at 10 Bits) ±0.024% (±1LSB at 12 Bits) 3.3 3.8 4.2 µs µs µs Voltage Output Slew Rate 1.0 V/µs Capacitive Load Driving 500 pF 2.1 nV•s Glitch Impulse At Mid-Scale Transition DAC-to-DAC Crosstalk 1 DAC Held at FS, 1 DAC Switch 0 – FS 2.1 nV•s Multiplying Bandwidth External Reference 320 kHz Output 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 nV/√Hz nV/√Hz 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 35 40 680 730 µVP-P µVP-P µVP-P µVP-P Rev E 6 For more information www.analog.com LTC2634 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. LTC2634-LMI12/-LMI10/-LMI8/-LMX12/-LMX10/-LMX8/-LZ12/-LZ10/-LZ8 (VFS = 2.5V) SYMBOL PARAMETER t1 SDI Valid to SCK Setup CONDITIONS l MIN 4 TYP MAX UNITS ns t2 SDI Valid to SCK Hold l 4 ns t3 SCK High Time l 9 ns t4 SCK Low Time l 9 ns t5 CS/LD Pulse Width l 10 ns t6 LSB SCK High to CS/LD High l 7 ns t7 CS/LD Low to SCK High l 7 ns t8 CLR Pulse Width l 20 ns t9 LDAC Pulse Width l 15 ns l 7 t10 CS/LD High to SCK Positive Edge SCK Frequency t11 CS/LD High to LDAC High or Low Transition t12 SDO Propagation Delay from SCK Falling Edge 50% Duty Cycle l CLOAD = 10pF VCC = 4.5V to 5.5V VCC = 2.7V to 5.5V l l ns 50 l 200 MHz ns 20 45 ns ns Rev E For more information www.analog.com 7 LTC2634 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. LTC2634-HMI12/-HMI10/-HMI8/-HMX12/-HMX10/-HMX8/-HZ12/-HZ10/-HZ8 (VFS = 4.096V) SYMBOL PARAMETER LTC2634-8 LTC2634-10 LTC2634-12 MIN TYP MAX MIN TYP MAX MIN TYP MAX CONDITIONS UNITS DC Performance Resolution DNL l 8 8 10 Monotonicity VCC = 5V, Internal Ref. (Note 4) l Differential Nonlinearity VCC = 5V, Internal Ref. (Note 4) l ±0.5 ±0.05 ±0.5 12 10 Bits 12 Bits ±0.5 ±1 LSB INL Integral Nonlinearity VCC = 5V, Internal Ref. (Note 4) l ±0.2 ±1 ±1 ±2.5 LSB ZSE Zero-Scale Error VCC = 5V, Internal Ref., Code = 0 l 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 mV VOSTC VOS Temperature Coefficient VCC = 5V, Internal Ref. GE Gain Error VCC = 5V, Internal Ref. GETC Gain Temperature Coefficient VCC = 5V, Internal Ref. (Note 10) C-Grade I-Grade H-Grade Load Regulation VCC = 5V ±10%, Internal Ref., Mid-Scale, –10mA ≤ IOUT ≤ 10mA l 0.006 0.01 0.022 0.04 0.09 0.16 LSB/ mA VCC = 5V ±10%, Internal Ref., Mid-Scale, –10mA ≤ IOUT ≤ 10mA l 0.09 0.156 0.09 0.156 0.09 0.156 Ω ROUT DC Output Impedance SYMBOL PARAMETER l ±10 ±10 ±10 µV/°C ±0.2 ±0.8 ±0.2 ±0.8 ±0.2 ±0.8 %FSR 10 10 10 10 10 10 CONDITIONS MIN VOUT DAC Output Span External Reference Internal Reference PSR Power Supply Rejection VCC = 5V ±10% 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 l l l 10 10 10 TYP ppm/°C ppm/°C ppm/°C MAX UNITS 0 to VREF 0 to 4.096 V V –80 dB 27 –27 48 –48 mA mA 5.5 V Power Supply VCC Positive Supply Voltage For Specified Performance ICC Supply Current (Note 7) VCC = 5V, VREF = 4.096V, External Reference l l VCC = 5V, Internal Reference 0.6 0.7 0.8 0.9 mA mA ISD Supply Current in Power-Down Mode (Note 7) VCC = 5V, C-Grade, I-Grade VCC = 5V, H-Grade 0.5 0.5 20 30 µA µA l l 4.5 Rev E 8 For more information www.analog.com LTC2634 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. LTC2634-HMI12/-HMI10/-HMI8/-HMX12/-HMX10/-HMX8/-HZ12/-HZ10/-HZ8 (VFS = 4.096V) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VCC V 200 kΩ 0.005 1.5 µA 2.048 2.064 Reference Input VREF Input Voltage Range l 1 Resistance l 120 Capacitance IREF Reference Current, Power-Down Mode 160 14 DAC Powered Down l pF Reference Output Output Voltage l 2.032 V Reference Temperature Coefficient ±10 ppm/°C Output Impedance 0.5 kΩ Capacitive Load Driving 10 µF 4 mA Short-Circuit Current VCC = 5.5V, REF Shorted to GND Digital I/O VIH Digital Input High Voltage l VIL Digital Input Low Voltage VOH Digital Output High Voltage Load Current = –100µA l VOL Digital Output Low Voltage Load Current = 100µA l ILK Digital Input Leakage VIN = GND to VCC CIN Digital Input Capacitance (Note 8) 2.4 V 0.8 l VCC – 0.4 V V 0.4 V l ±1 µA l 2.5 pF AC Performance tS en Settling Time VCC = 5V (Note 9) ±0.39% (±1LSB at 8 Bits) ±0.098% (±1LSB at 10 Bits) ±0.024% (±1LSB at 12 Bits) 3.8 4.2 4.8 µs µs µs Voltage Output Slew Rate 1.0 V/µs Capacitive Load Driving 500 pF 3.0 nV•s Glitch Impulse At Mid-Scale Transition DAC-to-DAC Crosstalk 1 DAC Held at FS, 1 DAC Switch 0 – FS 2.4 nV•s Multiplying Bandwidth External Reference 320 kHz Output 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 nV/√Hz nV/√Hz 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 35 50 680 750 µVP-P µVP-P µVP-P µVP-P Rev E For more information www.analog.com 9 LTC2634 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. LTC2634-HMI12/-HMI10/-HMI8/-HMX12/-HMX10/-HMX8/-HZ12/-HZ10/-HZ8 (VFS = 4.096V) SYMBOL PARAMETER t1 SDI Valid to SCK Setup l 4 ns t2 SDI Valid to SCK Hold l 4 ns t3 SCK High Time l 9 ns t4 SCK Low Time l 9 ns t5 CS/LD Pulse Width l 10 ns t6 LSB SCK High to CS/LD High l 7 ns t7 CS/LD Low to SCK High l 7 ns t8 CLR Pulse Width l 20 ns t9 LDAC Pulse Width l 15 ns t10 CS/LD High to SCK Positive Edge l 7 ns SCK Frequency t11 CS/LD High to LDAC High or Low Transition t12 SDO Propagation Delay from SCK Falling Edge CONDITIONS MIN 50% Duty Cycle CLOAD = 10pF VCC = 4.5V to 5.5V 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: Operating at temperatures above 90°C and with VCC > 4V requires VCC slew rates to be no greater than 73mV/µs. 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 (LTC2634-12), code 4 (LTC2634-10) or code 1 (LTC2634-8), and at full-scale. l MAX 50 l l TYP 200 UNITS MHz ns 20 ns 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. Rev E 10 For more information www.analog.com LTC2634 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. LTC2634-L12 (Internal Reference, VFS = 2.5V) Integral Nonlinearity (INL) 1.0 Differential Nonlinearity (DNL) 1.0 VCC = 3V 0.5 DNL (LSB) INL (LSB) 0.5 0 –0.5 –1.0 VCC = 3V 0 –0.5 0 1024 2048 CODE 3072 –1.0 4095 1024 0 2048 CODE 3072 2634 G01 INL vs Temperature 1.0 DNL (LSB) INL (LSB) 0 –1.0 –50 –25 25 50 75 100 125 150 TEMPERATURE (°C) DNL (POS) 0 DNL (NEG) 1.250 1.245 –1.0 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 1.240 –50 –25 0 2634 G04 2634 G03 Settling to ±1LSB Rising 25 50 75 100 125 150 TEMPERATURE (°C) 2634 G05 Settling to ±1LSB Falling CS/LD 5V/DIV 3/4 SCALE TO 1/4 SCALE STEP VCC = 3V, VFS = 2.5V RL = 2k, CL = 100pF AVERAGE OF 256 EVENTS VOUT 1LSB/DIV 3.1µs VOUT 1LSB/DIV VCC = 3V 1.255 –0.5 INL (NEG) 0 1.260 VCC = 3V 0.5 INL (POS) –0.5 Reference Output Voltage vs Temperature DNL vs Temperature VCC = 3V 0.5 2634 G02 VREF (V) 1.0 4095 4.2µs 1/4 SCALE TO 3/4 SCALE STEP VCC = 3V, VFS = 2.5V RL = 2k, CL = 100pF AVERAGE OF 256 EVENTS CS/LD 5V/DIV 2µs/DIV 2µs/DIV 2634 G06 2634 G07 Rev E For more information www.analog.com 11 LTC2634 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. LTC2634-H12 (Internal Reference, VFS = 4.096V) Integral Nonlinearity (INL) 1.0 Differential Nonlinearity (DNL) 1.0 VCC = 5V 0.5 DNL (LSB) INL (LSB) 0.5 0 –0.5 –1.0 VCC = 5V 0 –0.5 0 1024 2048 CODE 3072 –1.0 4095 0 1024 2048 CODE 3072 2634 G08 INL vs Temperature 1.0 VCC = 5V INL (POS) 2.068 VCC = 5V 0.5 0 INL (NEG) –0.5 –1.0 –50 –25 Reference Output Voltage vs Temperature DNL (POS) 0 DNL (NEG) –0.5 0 25 50 75 100 125 150 TEMPERATURE (°C) 2.048 2.038 –1.0 –50 –25 0 2.028 –50 –25 25 50 75 100 125 150 TEMPERATURE (°C) 2634 G10 0 2634 G11 Settling to ±1LSB Rising 25 50 75 100 125 150 TEMPERATURE (°C) 2634 G12 Settling to ±1LSB Falling CS/LD 5V/DIV 1/4 SCALE TO 3/4 SCALE STEP VCC = 5V, VFS = 4.095V RL = 2k, CL = 100pF AVERAGE OF 256 EVENTS VOUT 1LSB/DIV 4.8µs 3.8µs VOUT 1LSB/DIV VCC = 5V 2.058 VREF (V) INL (LSB) 0.5 2634 G09 DNL vs Temperature DNL (LSB) 1.0 4095 1/4 SCALE TO 3/4 SCALE STEP VCC = 5V, VFS = 4.095V RL = 2k, CL = 100pF AVERAGE OF 256 EVENTS CS/LD 5V/DIV 2µs/DIV 2µs/DIV 2634 G13 2634 G14 Rev E 12 For more information www.analog.com LTC2634 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted LTC2634-10 Integral Nonlinearity (INL) 1.0 Differential Nonlinearity (DNL) 1.0 VCC = 3V VFS = 2.5V INTERNAL REF 0.5 DNL (LSB) INL (LSB) 0.5 0 –0.5 –1.0 VCC = 3V VFS = 2.5V INTERNAL REF 0 –0.5 256 0 512 CODE 768 –1.0 1023 256 0 512 CODE 768 2634 G15 1023 2634 G16 LTC2634-8 Integral Nonlinearity (INL) 0.50 Differential Nonlinearity (DNL) 0.50 VCC = 3V VFS = 2.5V INTERNAL REF 0.25 DNL (LSB) INL (LSB) 0.25 0 –0.25 –0.50 VCC = 3V VFS = 2.5V INTERNAL REF 0 –0.25 0 64 128 CODE 192 –0.50 255 64 0 128 CODE 2634 G17 192 255 2634 G18 LTC2634 8 6 Current Limiting 0.20 VCC = 5V (LTC2634-H) VCC = 5V (LTC2634-L) VCC = 3V (LTC2634-L) 0.15 0.10 2 ∆VOUT (V) ∆VOUT (mV) 4 0 –2 –4 VCC = 5V (LTC2634-H) VCC = 5V (LTC2634-L) VCC = 3V (LTC2634-L) 2 0.05 0 –0.05 –0.01 –6 INTERNAL REF. CODE = MID-SCALE –8 –10 –30 Offset Error vs Temperature 3 OFFSET ERROR (mV) Load Regulation 10 –20 –10 0 10 IOUT (mA) 20 30 2634 G19 –0.15 –0.20 –30 INTERNAL REF. CODE = MID-SCALE –20 –10 0 10 IOUT (mA) 20 30 2634 G20 1 0 –1 –2 –3 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 2634 G21 Rev E For more information www.analog.com 13 LTC2634 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted LTC2634 Large-Signal Response Mid-Scale Glitch Impulse Power-On Reset Glitch LTC2634-L VCC 2V/DIV CS/LD 5V/DIV VOUT 0.5V/DIV LTC2634-H12, VCC = 5V 3.0nV•s TYP ZERO SCALE VOUT 5mV/DIV VOUT 5mV/DIV LTC2634-L12, VCC = 3V 2.1nV•s TYP VFS = VCC = 5V 1/4 SCALE to 3/4 SCALE 2µs/DIV 2µs/DIV 2634 G22 Headroom at Rails vs Output Current VCC = 5V INTERNAL REF 4.0 VOUT (V) VCC 2V/DIV CS/LD 2V/DIV 3V (LTC2634-L) SOURCING 3.0 LTC2634-H 2.5 2.0 1.5 DACs A-C IN POWER-DOWN MODE LTC2634-L VOUT 0.5V/DIV 3V (LTC2634-L) SINKING 0.5 0 VOUT 0.5V/DIV 5V SINKING 1.0 0 1 2 3 4 5 6 IOUT (mA) 7 8 9 5µs/DIV 10 200µs/DIV 2634 G26 2634 G27 2634 G25 Supply Current vs Logic Voltage 1.4 Hardware CLR Hardware CLR to Mid-Scale VCC = 5V VREF = 4.096V CODE = FULL-SCALE SWEEP SCK, SDI, CS/LD BETWEEN 0V AND VCC 1.2 VOUT 1V/DIV ICC (mA) Power-On Reset to Mid-Scale LTC2634-H 5V SOURCING 3.5 2636 G24 Exiting Power-Down to Mid-Scale 5.0 4.5 200µs/DIV 2634 G23 VOUT 1V/DIV VCC = 5V VREF = 4.096V CODE = FULL-SCALE 1.0 VCC = 5V 0.8 VCC = 3V (LTC2634-L) 0.6 0.4 0 1 3 2 LOGIC VOLTAGE (V) CLR 5V/DIV CLR 5V/DIV 4 5 1µs/DIV 1µs/DIV 2634 G29 2634 G30 2634 G28 Rev E 14 For more information www.analog.com LTC2634 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted LTC2634 Noise Voltage vs Frequency 500 0 NOISE VOLTAGE (nV/√Hz) –2 –4 –8 –10 –12 VCC = 5V VREF(DC) = 2V VREF(AC) = 0.2VP-P CODE = FULL-SCALE –14 –16 –18 1k 10k 100k FREQUENCY (Hz) VCC = 5V CODE = MID-SCALE INTERNAL REF VCC = 5.5V 0.8 GAIN ERROR OF 4 CHANNELS 0.6 300 LTC2634-H 200 LTC2634-L 100 0.4 0.2 0 –0.2 –0.4 –0.6 –0.8 1M 0 100 2636 G31 1k 10k 100k FREQUENCY (Hz) –1.0 1M 1 1.5 2 2.5 3 3.5 4 4.5 REFERENCE VOLTAGE (V) 0.1Hz to 10Hz Voltage Noise 5 5.5 2634 G33 2636 G32 DAC-to-DAC Crosstalk (Dynamic) Gain Error vs Temperature 1.0 VCC = 5V, VFS = 2.5V CODE = MID-SCALE INTERNAL REF CS/LD 5V/DIV GAIN ERROR (%FSR) dB –6 400 Gain Error vs Reference Input 1.0 GAIN ERROR (%FSR) Mulitplying Bandwidth 2 1 DAC SWITCH 0-FS 2V/DIV 10µV/DIV VOUT 1mV/DIV 1s/DIV LTC2634-H12, VCC = 5V 2.4nV•s TYP CREF = 0.1µF 2µs/DIV 2634 G34 2634 G35 0.5 0 –0.5 –1.0 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 2634 G36 Rev E For more information www.analog.com 15 LTC2634 PIN FUNCTIONS (QFN/MSOP) VOUTA to VOUTD (Pins 1-2, 11-12/Pins 2-3, 8-9): DAC Analog Voltage Outputs. LDAC (Pin 3, QFN Only): Asynchronous DAC Update Pin. If CS/LD is high, a falling edge on LDAC immediately updates the DAC registers with the contents of the input registers (similar to a software update). If CS/LD is low when LDAC goes low, the DAC registers are updated after CS/LD returns high. A low on the LDAC pin powers up the DACs. A software power-down command is ignored if LDAC is low. CS/LD (Pin 4/Pin 4): Serial Interface Chip Select/Load Input. When CS/LD is low, SCK is enabled for shifting data on SDI into the 32-bit shift register. When CS/LD is taken high, SCK is disabled and the specified command (see Table 1) is executed. SCK (Pin 5/Pin 5): Serial Interface Clock Input. CMOS and TTL compatible. DNC (Pins 6, 15, QFN Only): Do not connect these pins. SDO (Pin 7, QFN Only): Serial Interface Data Output. The serial output of the 32-bit shift register appears at the SDO pin. The data transferred to the device via the SDI pin is delayed 32 SCK rising edges before being output at the next falling edge. This pin is used for daisy-chain operation, it is always driven and never goes high impedance, even when CS/LD is high. See the Daisy-Chain Operation section. SDI (Pin 8/Pin 6): Serial Interface Data Input. Data on SDI is clocked into the DAC on the rising edge of SCK. The LTC2634 accepts input word lengths of either 24 or 32 bits. CLR (Pin 9, QFN Only): Asynchronous Clear Input. A logic low at this level-triggered input clears all registers and causes the DAC voltage output to reset to zero (LTC2634-Z) or mid-scale (LTC2634-MI/-MX). CMOS and TTL compatible. REF (Pin 10/Pin 7): 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 (LTC2634-L) or 2.048V (LTC2634-H) internal reference (half full-scale) is available at REF. This output may be bypassed to GND with up to 10µF and must be buffered when driving external DC load current. REFLO (Pin 13, QFN only): Reference Low Pin. The voltage at this pin sets the zero-scale voltage of all DACs. This pin must be tied to GND. GND (Pin 14/Pin 10): Ground. VCC (Pin 16/Pin 1): Supply Voltage Input. 2.7V ≤ VCC ≤ 5.5V (LTC2634-L) or 4.5V ≤ VCC ≤ 5.5V (LTC2634-H). Bypass to GND with a 0.1µF capacitor. Exposed Pad (Pin 17/Pin 11): Ground. Must be soldered to PCB ground. Rev E 16 For more information www.analog.com LTC2634 BLOCK DIAGRAM INTERNAL REFERENCE GND SWITCH REF VREF VCC REGISTER REGISTER DAC A REGISTER VOUTA REGISTER (REFLO) DAC D VREF REGISTER REGISTER REGISTER DAC B REGISTER VREF VOUTB VOUTD DAC C SDI CS/LD CONTROL LOGIC SCK VOUTC DECODE 32-BIT SHIFT REGISTER (LDAC) POWER-ON RESET (CLR) (SDO) 2634 BD ( ) QFN PACKAGE ONLY Rev E For more information www.analog.com 17 LTC2634 TIMING DIAGRAMS t1 t2 SCK t3 1 t6 t4 2 3 23 24 t10 SDI t5 t7 CS/LD t12 SDO t11 t9 LDAC 2634 F01a Figure 1a CS/LD t11 LDAC 2634 F01b Figure 1b Rev E 18 For more information www.analog.com LTC2634 OPERATION The LTC2634 is a family of quad voltage output DACs in 16-lead QFN and 10-lead MSOP packages. Each DAC can operate rail-to-rail using an external reference, or with its full-scale voltage set by an integrated reference. Eighteen 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 fullscale voltage (2.5V or 4.096V) are available. The LTC2634 is controlled using a 3-wire SPI/MICROWIRE compatible interface. Power Supply Sequencing The voltage at REF (Pin 10, QFN/Pin 7, MSOP) must be kept within the range –0.3V ≤ VREF ≤ VCC + 0.3V (see Absolute Maximum Ratings). Particular care should be taken to observe these limits during power supply turnon and turn-off sequences, when the voltage at VCC is in transition. Transfer Function The digital-to-analog transfer function is: Power-On Reset The LTC2634-HZ/LTC2634-LZ clear the output to zeroscale 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 LTC2634 contains circuitry to reduce the power-on glitch: the analog output typically rises less than 5mV above zeroscale during power on. 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 LTC2634-HMI/LTC2634-HMX/LTC2634-LMI/ LTC2634‑LMX provide an alternative reset, setting the output to mid-scale when power is first applied. The LTC2634-LMI and LTC2634-HMI power up in internal reference mode, with the output set to a mid-scale voltage of 1.25V and 2.048V, respectively. The LTC2634LMX and LTC2634-HMX power up in external reference mode, with the output set to mid-scale of the external reference. Default reference mode selection is described in the Reference Modes section. ⎛ k ⎞ VOUT(IDEAL) = ⎜ N ⎟ ( VREF – VREFLO ) + VREFLO ⎝2 ⎠ where k is the decimal equivalent of the binary DAC input code, N is the resolution, and VREF is either 2.5V (LTC2634-LMI/LTC2634-LMX/LTC2634-LZ) or 4.096V (LTC2634-HMI/LTC2634-HMX/LTC2634-HZ) when in internal reference mode, and the voltage at REF when in external reference mode. The resulting DAC output span is 0V to VREF , as it is necessary to tie REFLO to GND. 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 (LTC2634-12/LTC2634-10/LTC2634-8 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 Rev E For more information www.analog.com 19 LTC2634 OPERATION 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 register into the input register of the selected DAC, n. An update operation copies the data word from the input register to the DAC register. Once copied into the DAC register, the data word becomes the active 12-, 10- or 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. Input Word (LTC2634-12) COMMAND C3 C2 C1 C0 ADDRESS A3 A2 A1 DATA (12 BITS + 4 DON’T CARE BITS) A0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 MSB D0 X X X X X X X X X X X LSB Input Word (LTC2634-10) COMMAND C3 C2 C1 C0 ADDRESS A3 A2 A1 DATA (10 BITS + 6 DON’T CARE BITS) A0 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 MSB X X LSB Input Word (LTC2634-8) COMMAND C3 C2 C1 C0 ADDRESS A3 A2 A1 DATA (8 BITS + 8 DON’T CARE BITS) A0 D7 D6 D5 D4 D3 D2 D1 MSB D0 X X X X X 2634 F02 LSB Figure 2. Command and Data Input Format Table 1. Command Codes Table 2. Address Codes COMMAND* ADDRESS (n)* C3 C2 C1 C0 0 0 0 0 Write to Input Register n 0 0 0 0 DAC A 0 0 0 1 Update (Power Up) DAC Register n 0 0 0 1 DAC B A3 A2 A1 A0 0 0 1 0 Write to Input Register n, Update (Power Up) All 0 0 1 0 DAC C 0 0 1 1 Write to and Update (Power Up) DAC Register n 0 0 1 1 DAC D 0 1 0 0 Power-Down DAC n 1 1 1 1 All DACs 0 1 0 1 Power-Down Chip (All DACs 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 * Address codes not shown are reserved and should not be used. *Command codes not shown are reserved and should not be used. Rev E 20 For more information www.analog.com LTC2634 OPERATION While the minimum input sequence is 24 bits, it may optionally be extended to 32 bits to accommodate microprocessors that have a minimum word width of 16 bits (2 bytes). To use the 32-bit width, 8 don’t care bits must be transferred 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. Daisy-Chain Operation (QFN Package) The serial output of the shift register appears at the SDO pin on the QFN package. Data transferred to the device from the SDI input is delayed 32 SCK rising edges before being output at the next SCK falling edge, therefore, daisy chaining multiple LTC2634 DACs requires 32-bit data write cycles. The SDO output can be used to facilitate control of multiple serial devices from a single 3-wire serial port (i.e., SCK, SDI and CS/LD). Such a “daisy-chain” series is configured by connecting SDO of each upstream device to SDI of the next device in the chain. The shift registers of the devices are thus connected in series, effectively forming a single input shift register which extends through the entire chain. Because of this, the devices can be addressed and controlled individually by simply concatenating their input words; the first instruction addresses the last device in the chain and so forth. The SCK and CS/LD signals are common to all devices in the series. Figure 5 shows a block diagram for daisy-chain operation. In use, CS/LD is first taken low. Then the concatenated input data is transferred to the chain, using SDI of the first device as the data input. When the data transfer is complete, CS/LD is taken high, completing the instruction sequence for all devices simultaneously. A single device can be controlled by using the no-operation command (1111) for the other devices in the chain. Reference Modes For applications where an accurate external reference is either not available, or not desirable due to limited space, the LTC2634 has a low noise, user-selectable, integrated reference. The integrated reference voltage is internally amplified by 2x to provide the full-scale DAC output voltage range. The LTC2634-LMI/LTC2634-LMX/LTC2634-LZ provides a full-scale DAC output of 2.5V. The LTC2634HMI/LTC2634‑HMX/LTC2634-HZ provides a full-scale DAC 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 command 0110b, and is the power-on default for LTC2634-HZ/LTC2634-LZ, as well as for LTC2634-HMI/ LTC2634-LMI. The 10ppm/°C, 1.25V (LTC2634-LMI/LTC2634-LMX/ LTC2634-LZ) or 2.048V (LTC2634-HMI/LTC2634-HMX/ LTC2634-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. The REF 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 LTC2634-HMX/LTC2634-LMX. The reference mode of LTC2634-HZ/LTC2634-LZ/ LTC2634‑HMI/LTC2634-LMI (internal reference poweron default), can be changed by software command after power up. The same is true for LTC2634-HMX/-LMX (external reference power-on default). The LTC2634’s QFN package offers a REFLO pin for the negative reference. REFLO must be connected to GND. Rev E For more information www.analog.com 21 LTC2634 OPERATION Power-Down Mode For power-constrained applications, power-down mode can be used to reduce the supply current whenever less than four 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. Any DAC channel or combination of 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 20% 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 reference together can be put into powerdown mode using power-down chip command 0101b. When the integrated reference and all DAC channels are 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) or pulling the asynchronous LDAC pin low. The selected 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 four DACs are in a powered-down state prior to the update command, the power-up delay time is 10µs. However, if all four DACs and the integrated reference are powered down, then the main bias generation circuit block has been automatically 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 command (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 select internal reference command (0110b), any command (in software or using the LDAC pin) that powers up the DACs will also power up the integrated reference. Voltage Output The LTC2634’s integrated rail-to-rail amplifier has guaranteed 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 Characteristics section. The amplifier is stable driving capacitive loads of up to 500pF. Rev E 22 For more information www.analog.com LTC2634 OPERATION Rail-to-Rail Output Considerations In any rail-to-rail voltage output device, the output is limited 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. 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 LTC2634 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 LTC2634 is no more susceptible to this effect than any other parts of this type; on the contrary, 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 separate 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 LTC2634 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. Rev E For more information www.analog.com 23 24 X X SDI SDO SCK CS/LD 1 X X 2 X X 3 X 4 X X DON’T CARE X 5 C3 SDI C2 2 C1 3 X X 6 X X 7 4 7 A1 ADDRESS A2 6 A0 8 D11 9 D10 10 D9 D8 12 D7 13 D6 14 24-BIT INPUT WORD 11 D5 15 D3 17 DATA WORD D4 16 D2 18 D1 19 C3 C3 C2 10 C1 11 C2 C1 COMMAND WORD 9 C0 C0 For more information www.analog.com A3 A3 A2 14 A1 15 A2 A1 ADDRESS WORD 13 A0 A0 16 17 D11 D11 PREVIOUS 32-BIT INPUT WORD 12 D10 D10 18 t2 t4 t12 D5 D5 23 PREVIOUS D11 t3 17 D6 D6 22 SDO t1 D7 D7 21 D11 D8 D8 20 SDI SCK D9 D9 19 D3 25 X 21 D10 D4 18 D3 DATA WORD D4 24 D0 20 PREVIOUS D10 Figure 3a. LTC2634-12 24-Bit Load Sequence (Minimum Input Word) LTC2634-10 SDI Data Word: 10-Bit Input Code + 6 Don’t Care Bits LTC2634-8 SDI Data Word: 8-Bit Input Code + 8 Don’t Care Bits A3 5 D2 D2 26 X 22 D1 D1 27 X 23 D0 D0 28 X 24 X X 29 2634 F03a X X 30 X X 31 X X 2634 F03b CURRENT 32-BIT INPUT WORD 32 OPERATION Figure 3b. LTC2634-12 32-Bit Load Sequence (Required for Daisy-Chain Operation) LTC2634-10 SDI Data Word: 10-Bit Input Code + 6 Don’t Care Bits LTC2634-8 SDI Data Word: 8-Bit Input Code + 8 Don’t Care Bits X 8 C0 X COMMAND WORD 1 SCK CS/LD LTC2634 Rev E LTC2634 OPERATION POSITIVE FSE VREF = VCC VREF = VCC OUTPUT VOLTAGE OUTPUT VOLTAGE INPUT CODE 0V NEGATIVE OFFSET 2634 F04 (4c) OUTPUT VOLTAGE 0 2,048 INPUT CODE 4,095 (4a) 0V INPUT CODE (4b) Figure 4. Effects of Rail-to-Rail Operation on a DAC Transfer Curve (Shown in 12 Bits) (4a) Overall Transfer Function (4b) Effect of Negative Offset for Codes Near Zero (4c) Effect of Postitive Full-Scale Error for Codes Near Full-Scale SCK CS/LD SDI 4 CS/LD 5 SCK 6 SDI LTC2634UD SDO 7 4 CS/LD 5 SCK 6 SDI 4 CS/LD 5 SCK 6 SDI LTC2634UD SDO 7 LTC2634UD SDO 7 DATA OUTPUT • • • 2634 F05 Figure 5. Daisy-Chain Operation (QFN Only) Rev E For more information www.analog.com 25 0.1µF 7 + For more information www.analog.com 6 5 LT1634-1.25 30k –15V – OUTC –15V 4 1/2 LT1469 8 + – 0.1µF VDD 62 REFA DAC C DAC D 63 RCOM1 64 RIN1 61 ROFSA 15 IOUT1A 59 RFBA 60 GND 19 RVOSA 58 IOUT2A 2 DAC B DAC A LTC2755 + – 0.1µF 8 15V 30k OUTB LT1634-1.25 –15V 4 1/2 LT1469 –15V 3 2 + 5V – 15V 0.1µF OUTA 30k SERIAL BUS LT1634-1.25 –15V 0.1µF 1 0.1µF 6 5 4 3 2 7 SDI SCK CS/LD REF LTC6240 DAC B DAC A DAC C DAC D LTC2634MSE-LMI12 – 26 + GND VCC LTC2634 DACs Adjusts LTC2755-16 Offsets, Amplified with LT®1991 PGA to ±5V 10 8 9 1 5V 2634 TA02 0.1µF –15V 0.1µF 0.1µF 8 7 M9 9 M3 VCC 10 M1 6 OUT LT1991 1 REF P1 2 P3 VEE 5 3 4 P9 15V VOUT ±5V LTC2634 TYPICAL APPLICATION Rev E LTC2634 PACKAGE DESCRIPTION Please refer to http://www.linear.com/product/LTC2634#packaging for the most recent package drawings. UD Package 16-Lead Plastic QFN (3mm × 3mm) (Reference LTC DWG # 05-08-1691 Rev Ø) 0.70 ±0.05 3.50 ±0.05 1.45 ±0.05 2.10 ±0.05 (4 SIDES) PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 3.00 ±0.10 (4 SIDES) BOTTOM VIEW—EXPOSED PAD PIN 1 NOTCH R = 0.20 TYP OR 0.25 × 45° CHAMFER R = 0.115 TYP 0.75 ±0.05 15 PIN 1 TOP MARK (NOTE 6) 16 0.40 ±0.10 1 1.45 ± 0.10 (4-SIDES) 2 (UD16) QFN 0904 0.200 REF 0.00 – 0.05 NOTE: 1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WEED-2) 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 0.25 ±0.05 0.50 BSC Rev E For more information www.analog.com 27 LTC2634 PACKAGE DESCRIPTION Please refer to http://www.linear.com/product/LTC2634#packaging for the most recent package drawings. MSE Package 10-Lead Plastic MSOP, Exposed Die Pad (Reference LTC DWG # 05-08-1664 Rev I) BOTTOM VIEW OF EXPOSED PAD OPTION 1.88 ±0.102 (.074 ±.004) 5.10 (.201) MIN 1 0.889 ±0.127 (.035 ±.005) 1.68 ±0.102 (.066 ±.004) 0.05 REF 10 0.305 ± 0.038 (.0120 ±.0015) TYP RECOMMENDED SOLDER PAD LAYOUT 3.00 ±0.102 (.118 ±.004) (NOTE 3) DETAIL “B” CORNER TAIL IS PART OF DETAIL “B” THE LEADFRAME FEATURE. FOR REFERENCE ONLY NO MEASUREMENT PURPOSE 10 9 8 7 6 DETAIL “A” 0° – 6° TYP 1 2 3 4 5 GAUGE PLANE 0.53 ±0.152 (.021 ±.006) DETAIL “A” 0.18 (.007) 0.497 ±0.076 (.0196 ±.003) REF 3.00 ±0.102 (.118 ±.004) (NOTE 4) 4.90 ±0.152 (.193 ±.006) 0.254 (.010) 0.29 REF 1.68 (.066) 3.20 – 3.45 (.126 – .136) 0.50 (.0197) BSC 1.88 (.074) SEATING PLANE 1.10 (.043) MAX 0.17 – 0.27 (.007 – .011) TYP 0.50 (.0197) NOTE: BSC 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 6. EXPOSED PAD DIMENSION DOES INCLUDE MOLD FLASH. MOLD FLASH ON E-PAD SHALL NOT EXCEED 0.254mm (.010") PER SIDE. 0.86 (.034) REF 0.1016 ±0.0508 (.004 ±.002) MSOP (MSE) 0213 REV I Rev E 28 For more information www.analog.com LTC2634 REVISION HISTORY REV DATE DESCRIPTION A 10/09 Changes to Electrical Characteristics maximum limits. B 12/09 Change pin name to DNC. C 06/10 PAGE NUMBER 5, 6, 8, 9 2, 16 Revised Note 3 in the Electrical Characteristics section. 10 Added Typical Application and replaced Related Parts list. 30 D 04/18 Edits to Note 3. 10 E 03/19 Add #W for 8-bit and 10-bit Automotive Qualification 3 Rev E Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license For is granted implication or otherwise under any patent or patent rights of Analog Devices. moreby information www.analog.com 29 LTC2634 TYPICAL APPLICATION LTC2634 DACs Adjusts LTC2755-16 Offsets, Amplified with LT1991 PGA to ±5V 5V 15V 0.1µF 0.1µF 7 8 + 1/2 LT1469 – 4 15 VDD 5 RFBA 60 64 RIN1 2 IOUT1A 59 63 RCOM1 6 DAC A IOUT2A 2 3 RVOSA 58 0.1µF –15V + 15V LTC2755 61 ROFSA – 8 1/2 LT1469 + 0.1µF – 1 –15V 15V OUTA 4 62 REFA LTC6240 5V 7 0.1µF 0.1µF REF 2 LTC2634MSE-LMI12 DAC A DAC D DAC B DAC C VCC 1 0.1µF 9 LT1634-1.25 DAC D 30k 3 LT1634-1.25 –15V LT1634-1.25 + – OUTC DAC C – + DAC B 30k GND OUTB 30k SERIAL BUS –15V 4 5 6 8 CS/LD SCK GND 0.1µF 8 7 M9 9 V CC M3 10 M1 6 OUT LT1991 1 REF P1 2 P3 VEE 5 3 4 P9 –15V VOUT ±5V 0.1µF 10 SDI 19 –15V 2634 TA02 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC2654/LTC2655 Quad 16-/12 Bit, SPI/I2C VOUT DACs with 10ppm/°C Maximum Reference ±4LSB INL Maximum at 16 Bits and ±2mV Offset Error, Rail-to-Rail Output, 20-Lead 4mm × 4mm QFN and 16-Lead Narrow SSOP Packages LTC2604/ Quad 16-/14-/12-Bit, SPI VOUT DACs with External LTC2614/LTC2624 Reference 250µA per DAC, 2.5V to 5.5V Supply Range, Rail-to-Rail Output, 16-Lead SSOP Package LTC2609/ Quad 16-/14-/12-Bit VOUT DACs with I2C Interface LTC2619/LTC2629 250µA per DAC, 2.7V to 5.5V Supply Range, Rail-to-Rail Output with Separate VREF Pins for Each DAC LTC2635 Quad 12-/10-/8-Bit I2C VOUT DACs with 10ppm/°C Reference ±2.5LSB INL, 2.7V to 5.5V Supply Range, 10ppm/°C Reference, External REF Mode, 16-Pin 3mm × 3mm QFN and 10-Lead MSOP Packages LTC2656/LTC2657 Octal 16-/12 Bit, SPI/I2C VOUT DACs with 10ppm/°C Maximum Reference ±4LSB INL Maximum at 16 Bits and ±2mV Offset Error, Rail-to-Rail Output, 20-Lead 4mm × 5mm QFN and 16-Lead TSSOP Packages LTC2636/LTC2637 Octal 12-/10-/8-Bit, SPI/I2C 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, 14-Lead 4mm × 3mm DFN and 16-Lead MSOP Packages LTC2630/LTC2631 Single 12-/10-/8-Bit, SPI/ I2C VOUT DACs with 10ppm/°C Reference 180µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference, Rail-toRail Output, SC70 (LTC2630)/ThinSOT ™ (LTC2631) Packages LTC2640 Single 12-/10-/8-Bit, SPI VOUT DACs with 10ppm/°C Reference 180µA per DAC, 2.7V to 5.5V Supply Range, 10ppm/°C Reference, External REF Mode, Rail-to-Rail Output, ThinSOT Package LTC1664 Quad 10-Bit, Serial VOUT DAC VCC = 2.7V to 5.5V, Micropower, Rail-to-Rail Output in 16-Pin Narrow SSOP LT1991 Precision, 100µA Gain Selectable Amplifier Gain Accuracy of 0.04%, Gains from –13 to 14, 100µA precision Op Amp LT1469 Dual 90MHz, 22V/µs 16-Bit Accurate Operational Amplifier 90MHz Gain Bandwidth, 125µV Offset, 900ns, 22V/µs Slew Rate Precision Op Amp Amplifiers Rev E 30 D16828-0-3/19(E) For more information www.analog.com www.analog.com  ANALOG DEVICES, INC. 2009–2019