LTC1655/LTC1655L 16-Bit Rail-to-Rail Micropower DACs in SO-8 Package U DESCRIPTIO FEATURES The LTC(R)1655/LTC1655L are rail-to-rail voltage output, 16-bit digital-to-analog converters in an SO-8 package. They include an output buffer and a reference. The 3-wire serial interface is compatible with SPI/QSPI and MICROWIRETM protocols. The CLK input has a Schmitt trigger that allows direct optocoupler interface. 16-Bit Monotonicity Over Temperature Deglitched Rail-to-Rail Voltage Output SO-8 Package ICC(TYP): 600A Internal Reference: 2.048V (LTC1655) 1.25V (LTC1655L) Maximum DNL Error: 1LSB Settling Time: 20S to 1LSB 750kHz Max Update Rate Power-On Reset to Zero Volts 3-Wire Cascadable Serial Interface Low Cost Pin Compatible Upgrade for LTC1451 12-Bit DAC Family The LTC1655 has an onboard 2.048V reference that can be overdriven to a higher voltage. The output swings from 0V to 4.096V when using the internal reference. The typical power dissipation is 3.0mW on a single 5V supply. The LTC1655L has an onboard 1.25V reference that can be overdriven to a higher voltage. The output swings from 0V to 2.5V when using the internal reference. The typical power dissipation is 1.8mW on a single 3V supply. U APPLICATIO S The LTC1655/LTC1655L are pin compatible with Linear Technology's 12-bit VOUT DAC family, allowing an easy upgrade path. They are the only buffered 16-bit DACs in an SO-8 package and they include an onboard reference for standalone performance. Digital Calibration Industrial Process Control Automatic Test Equipment Cellular Telephones , LTC and LT are registered trademarks of Linear Technology Corporation. MICROWIRE is a trademark of National Semiconductor Corporation. W FU CTIO AL BLOCK DIAGRA U U Functional Block Diagram: 16-Bit Rail-to-Rail DAC LTC1655: 4.5V TO 5.5V LTC1655L: 2.7V TO 5.5V 8 LTC1655: 2.048V LTC1655L: 1.25V 6 0.6 16-BIT SHIFT REG AND DAC LATCH 16 16-BIT DAC + VOUT 7 - DNL ERROR (LSB) 3 CS/LD 0.8 REF 2 DIN P 1.0 REF VCC 1 CLK Differential Nonlinearity vs Input Code 0.4 0.2 0 - 0.2 - 0.4 - 0.6 4 DOUT - 0.8 TO OTHER DACS POWER-ON RESET - 1.0 0 GND 5 16384 32768 CODE 49152 65535 1655/55L TA01 1655/55L TA02 1 LTC1655/LTC1655L W U U W W U W ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER I FOR ATIO (Note 1) VCC to GND .............................................. - 0.5V to 7.5V TTL Input Voltage .................................... - 0.5V to 7.5V VOUT, REF ....................................... - 0.5V to VCC + 0.5V Maximum Junction Temperature ......................... 125C Operating Temperature Range LTC1655C/LTC1655LC ........................... 0C to 70C LTC1655I/LTC1655LI ........................ - 40C to 85C Storage Temperature Range ................ - 65C to 150C Lead Temperature (Soldering, 10 sec)................. 300C ORDER PART NUMBER TOP VIEW CLK 1 8 VCC DIN 2 7 VOUT CS/LD 3 6 REF DOUT 4 5 GND N8 PACKAGE 8-LEAD PDIP LTC1655CN8 LTC1655IN8 LTC1655CS8 LTC1655IS8 LTC1655LCN8 LTC1655LIN8 LTC1655LCS8 LTC1655LIS8 S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 125C, JA = 100C/W (N8) TJMAX = 125C, JA = 150C/W (S8) S8 PART MARKING 1655 1655I 1655L 1655LI Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS The denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VCC = 4.5V to 5.5V (LTC1655), VCC = 2.7V to 5.5V (LTC1655L); VOUT unloaded, REF unloaded, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS DAC DNL Resolution 16 Bits Monotonicity 16 Bits Differential Nonlinearity Guaranteed Monotonic (Note 2) LTC1655, REF = 2.2V, VCC = 5V (Note 8) (External) LTC1655L, REF = 2.2V, VCC = 5V (Note 8) (External) 0.3 0.5 1.0 1.0 LSB LSB 8 8 20 20 LSB LSB 3.0 3.5 mV mV 3.0 3.5 mV mV INL Integral Nonlinearity LTC1655, REF = 2.2V, VCC = 5V (Note 8) (External) LTC1655L, REF = 2.2V, VCC = 5V (Note 8) (External) ZSE Zero Scale Error LTC1655 LTC1655L VOS Offset Error Measured at Code 200 LTC1655, REF = 2.2V, VCC = 5V (Note 8) (External) LTC1655L, REF = 1.3V, VCC = 2.7V (Note 8) (External) VOSTC 0 0 0.5 0.5 5 Offset Error Tempco Gain Error REF = 2.2V (External), VCC = 5V (Note 8) 5 Gain Error Drift V/C 16 0.5 LSB ppm/C Power Supply VCC ICC 2 Positive Supply Voltage Supply Current For Specified Performance LTC1655 LTC1655L (Note 3) 4.5 2.7 600 5.5 5.5 V V 1200 A LTC1655/LTC1655L ELECTRICAL CHARACTERISTICS The denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VCC = 4.5V to 5.5V (LTC1655), VCC = 2.7V to 5.5V (LTC1655L); VOUT unloaded, REF unloaded, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Op Amp DC Performance Short-Circuit Current Low Short-Circuit Current High Output Impedance to GND Output Line Regulation VOUT Shorted to GND LTC1655 LTC1655L 70 70 120 140 mA mA VOUT Shorted to VCC LTC1655 LTC1655L 80 70 140 150 mA mA Input Code = 0 LTC1655 LTC1655L 40 70 120 160 3 mV/V Input Code = 65535, with Internal Reference AC Performance 0.3 0.7 Voltage Output Slew Rate (Note 4) Voltage Output Settling Time (Note 4) to 0.0015% (16-Bit Settling Time), VCC = 5V (Note 4) to 0.012% (13-Bit Settling Time), VCC = 5V 20 10 s s Digital Feedthrough (Note 5) 0.3 nV-s V/s Midscale Glitch Impulse DAC Switched Between 8000H and 7FFFH 12 nV-s Output Voltage Noise Spectral Density LTC1655, At 1kHz LTC1655L, At 1kHz 280 220 nVHz nVHz Reference Output Reference Output Voltage LTC1655 LTC1655L Reference Input Range (Notes 6, 7) LTC1655 LTC1655L Reference Output Tempco LTC1655 LTC1655L Reference Input Resistance LTC1655, REF Overdriven to 2.2V LTC1655L, REF Overdriven to 1.3V Reference Short-Circuit Current 2.036 1.240 2.048 1.250 2.2 1.3 8.5 7.0 IOUT = 100A Reference Output Voltage Noise Spectral Density LTC1655, At 1kHz LTC1655L, At 1kHz VIH Digital Input High Voltage LTC1655 LTC1655L VIL Digital Input Low Voltage LTC1655 LTC1655L VOH Digital Output High Voltage LTC1655, IOUT = - 1mA LTC1655L, IOUT = - 1mA VOL Digital Output Low Voltage LTC1655, IOUT = 1mA LTC1655L, IOUT = 1mA VCC /2 VCC /2 V V ppm/C ppm/C 13 13 k k Reference Output Line Regulation Reference Load Regulation V V 5 10 40 2.060 1.260 100 mA 1.5 mV/V 5 mV/A 150 115 nVHz nVHz Digital I/O 2.4 2.0 V V 0.8 0.6 VCC - 1.0 VCC - 0.7 V V V V 0.4 0.4 V V 3 LTC1655/LTC1655L ELECTRICAL CHARACTERISTICS The denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VCC = 4.5V to 5.5V (LTC1655), VCC = 2.7V to 5.5V (LTC1655L); VOUT unloaded, REF unloaded, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN ILEAK Digital Input Leakage VIN = GND to VCC CIN Digital Input Capacitance (Note 7) t1 DIN Valid to CLK Setup LTC1655 LTC1655L 40 60 ns ns t2 DIN Valid to CLK Hold LTC1655 LTC1655L 0 0 ns ns t3 CLK High Time LTC1655 LTC1655L 40 60 ns ns t4 CLK Low Time LTC1655 LTC1655L 40 60 ns ns t5 CS/LD Pulse Width LTC1655 LTC1655L 50 80 ns ns t6 LSB CLK to CS/LD LTC1655 LTC1655L 40 60 ns ns t7 CS/LD Low to CLK LTC1655 LTC1655L 20 30 ns ns t8 DOUT Output Delay LTC1655, CLOAD = 15pF LTC1655L, CLOAD = 15pF 20 20 t9 CLK Low to CS/LD Low LTC1655 LTC1655L 20 30 TYP MAX UNITS 10 A 10 pF Switching Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Nonlinearity is defined from code 128 to code 65535 (full scale). See Applications Information. Note 3: DAC switched between all 1s and all 0s. VFS = 4.096V. Note 4: Digital inputs at 0V or VCC. 4 120 300 ns ns ns ns Note 5: Part is clocked with pin toggling between 1s and 0s, CS/LD is low. Note 6: Reference can be overdriven (see Applications Information). Note 7: Guaranteed by design. Not subject to test. Note 8: Guaranteed by correlation for other reference and supply conditions. LTC1655/LTC1655L U W TYPICAL PERFORMANCE CHARACTERISTICS VCC = 5V (LTC1655), VCC = 3V (LTC1655L) unless otherwise noted. LTC1655L Differential Nonlinearity 1.0 1.0 0.8 0.8 DIFFERENTIAL NONLINEARITY (LSB) DIFFERENTIAL NONLINEARITY (LSB) TC1655 Differential Nonlinearity 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1.0 0 16,384 49,152 32,768 DIGITAL INPUT CODE 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1.0 65,535 0 16,384 49,152 32,768 DIGITAL INPUT CODE 1655/55L G01 1655/55L G01a LTC1655L Integral Nonlinearity 10 10 8 8 INTEGRAL NONLINEARITY (LSB) INTEGRAL NONLINEARITY (LSB) LTC1655 Integral Nonlinearity 6 4 2 0 -2 -4 -6 6 4 2 0 -2 -4 -6 -8 -8 -10 128 -10 0 16,384 49,152 32,768 DIGITAL INPUT CODE 65,535 16,480 49,184 32,832 DIGITAL INPUT CODE 65,535 1655/55L G02a 1655/55L G02 LTC1655 Minimum Supply Headroom for Full Output Swing vs Load Current LTC1655L Minimum Supply Headroom for Full Output Swing vs Load Current 2.0 1.2 VOUT < 1LSB VOUT = 4.096V CODE: ALL 1's 1.0 VOUT < 1LSB VOUT = 2.5V CODE: ALL 1's 1.8 1.6 125C 1.4 0.8 VCC - VOUT (V) VCC - VOUT (V) 65,535 125C 0.6 25C 0.4 -55C 1.2 25C 1.0 0.8 -55C 0.6 0.4 0.2 0.2 0 0 10 5 LOAD CURRENT (mA) 15 1655/55L G03 0 0 10 5 LOAD CURRENT (mA) 15 1655/55L G03a 5 LTC1655/LTC1655L U W TYPICAL PERFORMANCE CHARACTERISTICS VCC = 5V (LTC1655), VCC = 3V (LTC1655L) unless otherwise noted. LTC1655 Minimum Output Voltage vs Output Sink Current LTC1655L Minimum Output Voltage vs Output Sink Current 1.0 0.8 CODE: ALL 0s OUTPUT PULL-DOWN VOLTAGE (V) OUTPUT PULL-DOWN VOLTAGE (V) CODE: ALL 0s 0.8 0.6 125C 0.4 25C -55C 0.2 0 0 10 5 OUTPUT SINK CURRENT (mA) 0.6 25C -55C 0.4 0.2 0 15 125C 0 10 5 OUTPUT SINK CURRENT (mA) 1655/55L G04 1655/55L G04a LTC1655L Full-Scale Voltage vs Temperature LTC1655 Full-Scale Voltage vs Temperature 4.10 2.510 FULL-SCALE VOLTAGE (V) FULL-SCALE VOLTAGE (V) 15 4.09 4.08 4.07 -55 -25 5 35 65 TEMPERATURE (C) 95 125 2.505 2.500 2.495 2.490 -55 -25 5 35 65 TEMPERATURE (C) 1655/55L G05 95 125 1655/55L G05a LTC1655 Offset vs Temperature LTC1655L Offset vs Temperature 1.0 0.6 0.8 0.5 0.6 OFFSET (mV) OFFSET (mV) 0.4 0.2 0 -0.2 0.4 0.3 0.2 -0.4 -0.6 0.1 -0.8 -1.0 -55 -10 80 35 TEMPERATURE (C) 125 1655/55L G06 6 0 -55 -10 80 35 TEMPERATURE (C) 125 1655/55L G06a LTC1655/LTC1655L U W TYPICAL PERFORMANCE CHARACTERISTICS VCC = 5V (LTC1655), VCC = 3V (LTC1655L) unless otherwise noted. LTC1655 Supply Current vs Logic Input Voltage LTC1655L Supply Current vs Logic Input Voltage 1.0 3.0 SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) 2.6 2.2 1.8 1.4 0.8 0.6 1.0 0.4 0.6 0 1 3 4 2 LOGIC INPUT VOLTAGE (V) 0 5 1 2 LOGIC INPUT VOLTAGE (V) 1655/55L G07a 1655/55L G07 LTC1655L Supply Current vs Temperature 700 580 680 560 SUPPLY CURRENT (A) SUPPLY CURRENT (A) LTC1655 Supply Current vs Temperature 660 VCC = 5.5V 640 VCC = 5V 620 VCC = 4.5V 600 3 540 520 VCC = 3.3V 500 VCC = 3V 480 VCC = 2.7V 580 -55 -35 -15 460 -55 -35 -15 5 25 45 65 85 105 125 TEMPERATURE (C) 5 25 45 65 85 105 125 TEMPERATURE (C) 1655/55L G08 1655/55L G08a LTC1655 Large-Signal Transient Response LTC1655L Large-Signal Transient Response 5 3 VOUT UNLOADED TA = 25C VOUT UNLOADED TA = 25C OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 4 3 2 2 1 1 0 0 TIME (5s/DIV) TIME (5s/DIV) 1655/55L G09 1655/55L G10 7 LTC1655/LTC1655L U U U PIN FUNCTIONS CLK (Pin 1): The TTL Level Input for the Serial Interface Clock. GND (Pin 5): Ground. REF (Pin 6): Reference. Output of the internal reference is 2.048V (LTC1655), 1.25V (LTC1655L). There is a gain of two from this pin to the output. The reference can be overdriven from 2.2V to VCC/2 (LTC1655) and 1.3V to VCC/2 (LTC1655L). When tied to VCC/2, the output will swing from GND to VCC. The output can only swing to within its offset specification of VCC (see Applications Information). DIN (Pin 2): 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 and is loaded MSB first. The LTC1655/LTC1655L requires a 16-bit word. CS/LD (Pin 3): The TTL Level Input for the Serial Interface Enable and Load Control. When CS/LD is low, the CLK signal is enabled, so the data can be clocked in. When CS/LD is pulled high, data is loaded from the shift register into the DAC register, updating the DAC output. VOUT (Pin 7): Deglitched Rail-to-Rail Voltage Output. VOUT clears to 0V on power-up. VCC (Pin 8): Positive Supply Input. 4.5V VCC 5.5V (LTC1655), 2.7V VCC 5.5V (LTC1655L). Requires a 0.1F bypass capacitor to ground. DOUT (Pin 4): Output of the Shift Register. Becomes valid on the rising edge of the serial clock and swings from GND to VCC. WU W TI I G DIAGRA t1 t9 t2 t7 CLK DIN 1 D15 MSB 2 D14 t6 t3 t4 15 3 D13 D1 16 D0 LSB t5 CS/LD t8 DOUT D15 PREVIOUS WORD D14 PREVIOUS WORD D13 PREVIOUS WORD D0 PREVIOUS WORD D15 CURRENT WORD 1655/55L TD 8 LTC1655/LTC1655L U U DEFI ITIO S Differential Nonlinearity (DNL): The difference between the measured change and the ideal 1LSB change for any two adjacent codes. The DNL error between any two codes is calculated as follows: DNL = (VOUT - LSB)/LSB Where VOUT is the measured voltage difference between two adjacent codes. 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). Full-Scale Error (FSE): The deviation of the actual fullscale voltage from ideal. FSE includes the effects of offset and gain errors (see Applications Information). Gain Error (GE): The difference between the full-scale output of a DAC from its ideal full-scale value after offset error has been adjusted. Integral Nonlinearity (INL): The deviation from a straight line passing through the endpoints of the DAC transfer curve (Endpoint INL). Because the output cannot go below zero, the linearity is measured between full scale and the lowest code that guarantees the output will be greater than zero. The INL error at a given input code is calculated as follows: INL = [VOUT - VOS - (VFS - VOS)(code/65535)]/LSB Where VOUT is the output voltage of the DAC measured at the given input code. Least Significant Bit (LSB): The ideal voltage difference between two successive codes. LSB = 2VREF/65536 Resolution (n): Defines the number of DAC output states (2n) that divide the full-scale range. Resolution does not imply linearity. Voltage Offset Error (VOS): Nominally, the voltage at the output when the DAC is loaded with all zeros. A single supply DAC can have a true negative offset, but the output cannot go below zero (see Applications Information). For this reason, single supply DAC offset is measured at the lowest code that guarantees the output will be greater than zero. U OPERATIO Serial Interface 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 clock 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 input word must be 16 bits wide. The buffered output of the 16-bit shift register is available on the DOUT pin which swings from GND to VCC. Multiple LTC1655s/LTC1655Ls may be daisy-chained together by connecting the DOUT pin to the DIN pin of the next chip while the clock and CS/LD signals remain common to all chips in the daisy chain. The serial data is clocked to all of the chips, then the CS/LD signal is pulled high to update all of them simultaneously. The shift register and DAC register are cleared to all 0s on power-up. Voltage Output The LTC1655/LTC1655L rail-to-rail buffered output can source or sink 5mA over the entire operating temperature range while pulling to within 600mV of the positive supply voltage or ground. The output stage is equipped with a deglitcher that gives a midscale glitch of 12nV-s. At powerup, the output clears to 0V. The output swings to within a few millivolts of either supply rail when unloaded and has an equivalent output resistance of 40 (70 for the LTC1655L) when driving a load to the rails. The output can drive 1000pF without going into oscillation. 9 LTC1655/LTC1655L U W U U APPLICATIONS INFORMATION Rail-to-Rail Output Considerations In any rail-to-rail DAC, the output swing is limited to voltages within the supply range. If the DAC offset is negative, the output for the lowest codes limits at 0V as shown in Figure 1b. error (FSE) is positive, the output for the highest codes limits at VCC as shown in Figure 1c. No full-scale limiting can occur if VREF is less than (VCC - FSE)/2. Offset and linearity are defined and tested over the region of the DAC transfer function where no output limiting can occur. Similarly, limiting can occur near full-scale when the REF pin is tied to VCC /2. If VREF = VCC /2 and the DAC full-scale VCC VREF = VCC /2 POSITIVE FSE OUTPUT VOLTAGE INPUT CODE (1c) VCC VREF = VCC /2 OUTPUT VOLTAGE 0 32768 INPUT CODE 65535 (1a) OUTPUT VOLTAGE 0V NEGATIVE OFFSET INPUT CODE (1b) 1655/55L F01 Figure 1. Effects of Rail-to-Rail Operation On a DAC Transfer Curve. (a) Overall Transfer Function (b) Effect of Negative Offset for Codes Near Zero Scale (c) Effect of Positive Full-Scale Error for Input Codes Near Full Scale When VREF = VCC /2 10 LTC1655/LTC1655L U TYPICAL APPLICATIONS This circuit shows how to use an LTC1655 to make an optoisolated digitally controlled 4mA to 20mA process controller. The controller circuitry, including the optoisolation, is powered by the loop voltage that can have a wide range of 6V to 30V. The 2.048V reference output of the LTC1655 is used for the 4mA offset current and VOUT is used for the digitally controlled 0mA to 16mA current. RS is a sense resistor and the op amp modulates the transistor Q1 to provide the 4mA to 20mA current through this resistor. The potentiometers allow for offset and fullscale adjustment. The control circuitry dissipates well under the 4mA budget at zero scale. An Isolated 4mA to 20mA Process Controller VLOOP 6V TO 30V LT (R)1121-5 IN OUT 1F 1 FROM OPTOISOLATED INPUTS 2 3 CLK 8 6 VCC VREF DIN VOUT LTC1655 10k 4N28 5k 3 + 7 3k 2 - 6 1k Q1 2N3440 4 RS 10 5V 500 75k 1% LT(R)1077 5 CLK DIN CS/LD 20k CS/LD GND OPTOISOLATORS 7 150k 1% IOUT CLK DIN CS/LD 1655/55L TA03 11 LTC1655/LTC1655L U TYPICAL APPLICATIONS the onboard reference is always sourcing current and never has to sink any current even when VOUT is at full scale. The LT1077 output will have a wide bipolar output swing of - 4.096V to 4.096V as shown in the figure below. With this output swing 1LSB = 125V. This circuit shows how to make a bipolar output 16-bit DAC with a wide output swing using an LTC1655 and an LT1077. R1 and R2 resistively divide down the LTC1655 output and an offset is summed in using the LTC1655 onboard 2.048V reference and R3 and R4. R5 ensures that A Wide Swing, Bipolar Output 16-Bit DAC 5V 0.1F 8 1 P 2 3 VCC CLK DIN CS/LD VOUT LTC1655 GND VREF 5 6 R1 100k 1% R2 200k 1% TRANSFER CURVE 4.096 VOUT - 4.096 12 0 32768 7 65535 R3 100k 1% DIN 5V 3 + 7 LT1077 2 - 6 VOUT: (2)(DIN)(4.096) - 4.096V 65536 4 R4 - 5V 200k 1% 1655/55L TA05 R5 100k 1% LTC1655/LTC1655L U TYPICAL APPLICATIONS This circuit shows a digitally programmable current source from an external voltage source using an external op amp, an LT1218 and an NPN transistor (2N3440). Any digital word from 0 to 65535 is loaded into the LTC1655 and its output correspondingly swings from 0V to 4.096V. This voltage will be forced across the resistor RA. If RA is chosen to be 412, the output current will range from 0mA at zero scale to 10mA at full scale. The minimum voltage for VS is determined by the load resistor RL and Q1's VCESAT voltage. With a load resistor of 50, the voltage source can be 5V. Digitally Programmable Current Source 5V 8 1 P 2 3 5V < VS < 100V FOR RL 50 0.1F VCC CLK DIN LTC1655 CS/LD GND 5 VOUT 7 3 2 + LT1218 - RL 7 6 Q1 2N3440 (DIN)(4.096) (65536)(RA) 0mA TO 10mA IOUT = 4 RA 412 1% 1655/55L TA04 13 LTC1655/LTC1655L U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.400* (10.160) MAX 8 7 6 5 1 2 3 4 0.255 0.015* (6.477 0.381) 0.300 - 0.325 (7.620 - 8.255) 0.009 - 0.015 (0.229 - 0.381) ( +0.035 0.325 -0.015 8.255 +0.889 -0.381 ) 0.045 - 0.065 (1.143 - 1.651) 0.065 (1.651) TYP 0.100 (2.54) BSC *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) 14 0.130 0.005 (3.302 0.127) 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 0.003 (0.457 0.076) N8 1098 LTC1655/LTC1655L U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 - 0.197* (4.801 - 5.004) 8 7 6 5 0.150 - 0.157** (3.810 - 3.988) 0.228 - 0.244 (5.791 - 6.197) 1 0.010 - 0.020 x 45 (0.254 - 0.508) 0.008 - 0.010 (0.203 - 0.254) 0.053 - 0.069 (1.346 - 1.752) 0- 8 TYP 0.016 - 0.050 (0.406 - 1.270) 0.014 - 0.019 (0.355 - 0.483) TYP *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 2 3 4 0.004 - 0.010 (0.101 - 0.254) 0.050 (1.270) BSC Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. SO8 1298 15 LTC1655/LTC1655L U TYPICAL APPLICATION This circuit shows how to measure negative offset. Since LTC1655/LTC1655L operate on a single supply, if its offset is negative, the output for code 0 limits to 0V. To measure this negative offset, a negative supply is needed. Connect resistor R1 as shown in the figure below. The output voltage is the offset when code 0 is loaded in. Negative Offset Measurement 5V 0.1F 8 1 P 2 3 VCC CLK DIN CS/LD LTC1655/ LTC1655L VOUT 7 R1 100k GND 5 -5V 1655/55L TA06 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC1257 Single 12-Bit VOUT DAC, Full Scale: 2.048V, VCC: 4.75V to 15.75V, in Reference Can Be Overdriven Up to 12V, i.e., FSMAX = 12V 5V to 15V Single Supply, Complete VOUT DAC SO-8 Package LTC1446/ LTC1446L Dual 12-Bit VOUT DACs in SO-8 Package LTC1446: VCC = 4.5V to 5.5V, VOUT = 0V to 4.095V LTC1446L: VCC = 2.7V to 5.5V, VOUT = 0V to 2.5V LTC1448 Dual 12-Bit VOUT DAC, VCC: 2.7V to 5.5V Output Swings from GND to REF. REF Input Can Be Tied to VCC LTC1450/ LTC1450L Single 12-Bit VOUT DACs with Parallel Interface LTC1450: VCC = 4.5V to 5.5V, VOUT = 0V to 4.095V LTC1450L: VCC = 2.7V to 5.5V, VOUT = 0V to 2.5V LTC1451 Single Rail-to-Rail 12-Bit DAC, Full Scale: 4.095V, VCC: 4.5V to 5.5V, Internal 2.048V Reference Brought Out to Pin 5V, Low Power Complete VOUT DAC in SO-8 Package LTC1452 Single Rail-to-Rail 12-Bit VOUT Multiplying DAC, VCC: 2.7V to 5.5V Low Power, Multiplying VOUT DAC with Rail-to-Rail Buffer Amplifier in SO-8 Package LTC1453 Single Rail-to-Rail 12-Bit VOUT DAC, Full Scale: 2.5V, VCC: 2.7V to 5.5V 3V, Low Power, Complete VOUT DAC in SO-8 Package LTC1454/ LTC1454L Dual 12-Bit VOUT DACs in SO-16 Package with Added Functionality LTC1454: VCC = 4.5V to 5.5V, VOUT = 0V to 4.095V LTC1454L: VCC = 2.7V to 5.5V, VOUT = 0V to 2.5V LTC1456 Single Rail-to-Rail Output 12-Bit DAC with Clear Pin, Full Scale: 4.095V, VCC: 4.5V to 5.5V Low Power, Complete VOUT DAC in SO-8 Package with Clear Pin LTC1458/ LTC1458L Quad 12 Bit Rail-to-Rail Output DACs with Added Functionality LTC1458: VCC = 4.5V to 5.5V, VOUT = 0V to 4.095V LTC1458L: VCC = 2.7V to 5.5V, VOUT = 0V to 2.5V LTC1650 Single 16-Bit VOUT Industrial DAC in 16-Pin SO, VCC = 5V Low Power, Deglitched, 4-Quadrant Mulitplying VOUT DAC, Output Swing 4.5V LTC1654 Dual 14-Bit DAC 1LSB DNL, 2 DACs in SO-8 Footprint LTC1657/ LTC1657L Single 16-Bit VOUT DAC with Parallel Interface LTC1657: VCC = 5V, Low Power, Deglitched, VOUT = 0V to 4.096V LTC1657L: VCC = 3V, Low Power, Deglitched, VOUT = 0V to 2.5V LTC1658 Single Rail-to-Rail 14-Bit VOUT DAC in 8-Pin MSOP, VCC = 2.7V to 5.5V Low Power, Multiplying VOUT DAC in MS8 Package. Output Swings from GND to REF. REF Input Can Be Tied to VCC LTC1659 Single Rail-to-Rail 12-Bit VOUT DAC in 8-Pin MSOP, VCC = 2.7V to 5.5V Low Power, Multiplying VOUT DAC in MS8 Package. Output Swings from GND to REF. REF Input Can Be Tied to VCC 16 Linear Technology Corporation 16555lf LT/TP 0800 4K * PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 FAX: (408) 434-0507 www.linear-tech.com LINEAR TECHNOLOGY CORPORATION 1998