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LTC1655/LTC1655L 16-Bit Rail-to-Rail Micropower DACs in SO-8 Package
FEATURES
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DESCRIPTIO
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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 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. 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. 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.
, LTC and LT are registered trademarks of Linear Technology Corporation. MICROWIRE is a trademark of National Semiconductor Corporation.
APPLICATIO S
s s s s
Digital Calibration Industrial Process Control Automatic Test Equipment Cellular Telephones
FU CTIO AL BLOCK DIAGRA
LTC1655: 4.5V TO 5.5V LTC1655L: 2.7V TO 5.5V 8 VCC 2 DIN 1 CLK P 3 CS/LD 16-BIT SHIFT REG AND DAC LATCH 16 16-BIT DAC REF LTC1655: 2.048V LTC1655L: 1.25V 6 REF
Functional Block Diagram: 16-Bit Rail-to-Rail DAC
1.0 0.8 0.6
DNL ERROR (LSB)
0.4 0.2 0 - 0.2 - 0.4 - 0.6 - 0.8
+ -
VOUT 7
4 DOUT POWER-ON RESET GND 5
1655/55L TA01
TO OTHER DACS
- 1.0 0 16384 32768 CODE 49152 65535
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Differential Nonlinearity vs Input Code
1655/55L TA02
W
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1
LTC1655/LTC1655L ABSOLUTE MAXIMUM RATINGS
(Note 1)
PACKAGE/ORDER I FOR ATIO
ORDER PART NUMBER
TOP VIEW CLK 1 DIN 2 CS/LD 3 DOUT 4 N8 PACKAGE 8-LEAD PDIP 8 7 6 5 VCC VOUT REF GND
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
S8 PACKAGE 8-LEAD PLASTIC SO
TJMAX = 125C, JA = 100C/W (N8) TJMAX = 125C, JA = 150C/W (S8)
LTC1655CN8 LTC1655IN8 LTC1655CS8 LTC1655IS8 LTC1655LCN8 LTC1655LIN8 LTC1655LCS8 LTC1655LIS8 S8 PART MARKING 1655 1655I 1655L 1655LI
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
The q 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 DAC Resolution Monotonicity DNL Differential Nonlinearity Guaranteed Monotonic (Note 2) LTC1655, REF = 2.2V, VCC = 5V (Note 8) (External) LTC1655L, REF = 2.2V, VCC = 5V (Note 8) (External) LTC1655, REF = 2.2V, VCC = 5V (Note 8) (External) LTC1655L, REF = 2.2V, VCC = 5V (Note 8) (External) LTC1655 LTC1655L
q q q q q q q q
PARAMETER
CONDITIONS
MIN 16 16
TYP
MAX
UNITS Bits Bits
0.3 0.5 8 8 0 0 0.5 0.5 5 5 0.5
1.0 1.0 20 20 3.0 3.5 3.0 3.5 16
INL ZSE VOS
Integral Nonlinearity Zero Scale Error Offset Error
Measured at Code 200 q LTC1655, REF = 2.2V, VCC = 5V (Note 8) (External) LTC1655L, REF = 1.3V, VCC = 2.7V (Note 8) (External) q REF = 2.2V (External), VCC = 5V (Note 8)
q
VOSTC
Offset Error Tempco Gain Error Gain Error Drift
V/C LSB ppm/C
Power Supply VCC Positive Supply Voltage For Specified Performance LTC1655 LTC1655L (Note 3)
q q q
4.5 2.7 600
5.5 5.5 1200
ICC
Supply Current
2
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LSB LSB LSB LSB mV mV mV mV V V A
W
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WW
W
LTC1655/LTC1655L
ELECTRICAL CHARACTERISTICS
The q 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 Short-Circuit Current Low CONDITIONS VOUT Shorted to GND LTC1655 LTC1655L VOUT Shorted to VCC LTC1655 LTC1655L Input Code = 0 LTC1655 LTC1655L Input Code = 65535, with Internal Reference (Note 4) (Note 4) to 0.0015% (16-Bit Settling Time), VCC = 5V (Note 4) to 0.012% (13-Bit Settling Time), VCC = 5V (Note 5) DAC Switched Between 8000H and 7FFFH LTC1655, At 1kHz LTC1655L, At 1kHz LTC1655 LTC1655L (Notes 6, 7) LTC1655 LTC1655L LTC1655 LTC1655L LTC1655, REF Overdriven to 2.2V LTC1655L, REF Overdriven to 1.3V
q q q q q q
MIN
TYP
MAX
UNITS
Op Amp DC Performance
q q q q q q
70 70 80 70 40 70
120 140 140 150 120 160 3
mA mA mA mA mV/V V/s s s nV-s nV-s nVHz nVHz
Short-Circuit Current High
Output Impedance to GND
Output Line Regulation AC Performance Voltage Output Slew Rate Voltage Output Settling Time Digital Feedthrough Midscale Glitch Impulse Output Voltage Noise Spectral Density Reference Output Reference Output Voltage Reference Input Range Reference Output Tempco Reference Input Resistance Reference Short-Circuit Current Reference Output Line Regulation Reference Load Regulation Reference Output Voltage Noise Spectral Density Digital I/O VIH VIL VOH VOL Digital Input High Voltage Digital Input Low Voltage Digital Output High Voltage Digital Output Low Voltage
0.3
0.7 20 10 0.3 12 280 220
2.036 1.240 2.2 1.3
2.048 1.250
2.060 1.260 VCC /2 VCC /2
V V V V ppm/C ppm/C k k
5 10 8.5 7.0 13 13 40 100 1.5 5 150 115
q q q q q q q q
mA mV/V mV/A nVHz nVHz V V
IOUT = 100A LTC1655, At 1kHz LTC1655L, At 1kHz LTC1655 LTC1655L LTC1655 LTC1655L LTC1655, IOUT = - 1mA LTC1655L, IOUT = - 1mA LTC1655, IOUT = 1mA LTC1655L, IOUT = 1mA
q
2.4 2.0 0.8 0.6 VCC - 1.0 VCC - 0.7 0.4 0.4
V V V V V V
3
LTC1655/LTC1655L
ELECTRICAL CHARACTERISTICS
The q 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 ILEAK CIN Switching t1 t2 t3 t4 t5 t6 t7 t8 t9 DIN Valid to CLK Setup DIN Valid to CLK Hold CLK High Time CLK Low Time CS/LD Pulse Width LSB CLK to CS/LD CS/LD Low to CLK DOUT Output Delay CLK Low to CS/LD Low LTC1655 LTC1655L LTC1655 LTC1655L LTC1655 LTC1655L LTC1655 LTC1655L LTC1655 LTC1655L LTC1655 LTC1655L LTC1655 LTC1655L LTC1655, CLOAD = 15pF LTC1655L, CLOAD = 15pF LTC1655 LTC1655L
q q q q q q q q q q q q q q q q q q
PARAMETER Digital Input Leakage Digital Input Capacitance
CONDITIONS VIN = GND to VCC (Note 7)
q
MIN
TYP
MAX 10 10
UNITS A pF ns ns ns ns ns ns ns ns ns ns ns ns ns ns
40 60 0 0 40 60 40 60 50 80 40 60 20 30 20 20 20 30 120 300
ns ns ns ns
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.
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.
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LTC1655/LTC1655L TYPICAL PERFORMANCE CHARACTERISTICS
VCC = 5V (LTC1655), VCC = 3V (LTC1655L) unless otherwise noted. TC1655 Differential Nonlinearity
1.0
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 65,535
DIFFERENTIAL NONLINEARITY (LSB)
DIFFERENTIAL NONLINEARITY (LSB)
0.8
LTC1655 Integral Nonlinearity
10 8
INTEGRAL NONLINEARITY (LSB)
INTEGRAL NONLINEARITY (LSB)
6 4 2 0 -2 -4 -6 -8 -10 0 16,384 49,152 32,768 DIGITAL INPUT CODE 65,535
LTC1655 Minimum Supply Headroom for Full Output Swing vs Load Current
1.2 1.0 0.8 125C 0.6 25C 0.4 0.2 0 0 -55C VOUT < 1LSB VOUT = 4.096V CODE: ALL 1's
VCC - VOUT (V)
VCC - VOUT (V)
10 5 LOAD CURRENT (mA)
UW
LTC1655L Differential Nonlinearity
1.0 0.8 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 65,535
1655/55L G01
1655/55L G01a
LTC1655L Integral Nonlinearity
10 8 6 4 2 0 -2 -4 -6 -8 -10 128 16,480 49,184 32,832 DIGITAL INPUT CODE 65,535
1655/55L G02
1655/55L G02a
LTC1655L Minimum Supply Headroom for Full Output Swing vs Load Current
2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 -55C 25C VOUT < 1LSB VOUT = 2.5V CODE: ALL 1's
125C
15
1655/55L G03
0
0
10 5 LOAD CURRENT (mA)
15
1655/55L G03a
5
LTC1655/LTC1655L TYPICAL PERFORMANCE CHARACTERISTICS
VCC = 5V (LTC1655), VCC = 3V (LTC1655L) unless otherwise noted. LTC1655 Minimum Output Voltage vs Output Sink Current
1.0 CODE: ALL 0s
OUTPUT PULL-DOWN VOLTAGE (V)
OUTPUT PULL-DOWN VOLTAGE (V)
0.8
0.6 125C 0.4 25C 0.2 -55C
0
0
10 5 OUTPUT SINK CURRENT (mA)
LTC1655 Full-Scale Voltage vs Temperature
4.10
FULL-SCALE VOLTAGE (V)
FULL-SCALE VOLTAGE (V)
4.09
4.08
4.07 -55
-25
5 35 65 TEMPERATURE (C)
LTC1655 Offset vs Temperature
1.0 0.8 0.6 0.4
OFFSET (mV)
0.2 0 -0.2 -0.4 -0.6 -0.8 -1.0 -55 -10 80 35 TEMPERATURE (C) 125
1655/55L G06
OFFSET (mV)
6
UW
LTC1655L Minimum Output Voltage vs Output Sink Current
0.8 CODE: ALL 0s
0.6
125C
25C
-55C
0.4
0.2
15
1655/55L G04
0
0
10 5 OUTPUT SINK CURRENT (mA)
15
1655/55L G04a
LTC1655L Full-Scale Voltage vs Temperature
2.510
2.505
2.500
2.495
95
125
2.490 -55
-25
5 35 65 TEMPERATURE (C)
95
125
1655/55L G05
1655/55L G05a
LTC1655L Offset vs Temperature
0.6 0.5 0.4 0.3 0.2 0.1 0 -55
-10 80 35 TEMPERATURE (C)
125
1655/55L G06a
LTC1655/LTC1655L TYPICAL PERFORMANCE CHARACTERISTICS
VCC = 5V (LTC1655), VCC = 3V (LTC1655L) unless otherwise noted. LTC1655 Supply Current vs Logic Input Voltage
3.0 2.6
SUPPLY CURRENT (mA) SUPPLY CURRENT (mA)
2.2 1.8 1.4 1.0 0.6 0 1 3 4 2 LOGIC INPUT VOLTAGE (V) 5
1655/55L G07
LTC1655 Supply Current vs Temperature
700 680
SUPPLY CURRENT (A)
660 VCC = 5.5V 640 620 600 580 -55 -35 -15 VCC = 5V
SUPPLY CURRENT (A)
VCC = 4.5V
5 25 45 65 85 105 125 TEMPERATURE (C)
1655/55L G08
LTC1655 Large-Signal Transient Response
5 VOUT UNLOADED TA = 25C 4 3
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
3
2
1
0 TIME (5s/DIV)
1655/55L G09
UW
LTC1655L Supply Current vs Logic Input Voltage
1.0
0.8
0.6
0.4 0 1 2 LOGIC INPUT VOLTAGE (V) 3
1655/55L G07a
LTC1655L Supply Current vs Temperature
580 560 540 520 500 VCC = 3V 480 VCC = 2.7V 460 -55 -35 -15 5 25 45 65 85 105 125 TEMPERATURE (C)
1655/55L G08a
VCC = 3.3V
LTC1655L Large-Signal Transient Response
VOUT UNLOADED TA = 25C
2
1
0 TIME (5s/DIV)
1655/55L G10
7
LTC1655/LTC1655L
PIN FUNCTIONS
CLK (Pin 1): The TTL Level Input for the Serial Interface Clock. 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. DOUT (Pin 4): Output of the Shift Register. Becomes valid on the rising edge of the serial clock and swings from GND to VCC. 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). 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.
TI I G DIAGRA
t9 t7 CLK 1
DIN
CS/LD
DOUT
D15 PREVIOUS WORD
8
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t1 t2 2 t4 t3 3 15 16 t6
D15 MSB
D14
D13
D1
D0 LSB t5
t8 D14 PREVIOUS WORD D13 PREVIOUS WORD D0 PREVIOUS WORD D15 CURRENT WORD
1655/55L TD
LTC1655/LTC1655L
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.
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
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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
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. 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 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.
VCC
OUTPUT VOLTAGE
VREF = VCC /2
0
OUTPUT VOLTAGE
0V NEGATIVE OFFSET INPUT CODE
(1b)
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
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VCC
POSITIVE FSE
VREF = VCC /2
OUTPUT VOLTAGE
INPUT CODE
(1c)
32768 INPUT CODE
65535
(1a)
1655/55L F01
LTC1655/LTC1655L
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.
LT (R)1121-5 IN OUT 1F FROM OPTOISOLATED INPUTS 1 2 3 8 CLK DIN CS/LD GND 5 VCC 6 VREF VOUT 7
OPTOISOLATORS
CLK DIN CS/LD
500
4N28
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An Isolated 4mA to 20mA Process Controller
VLOOP 6V TO 30V 150k 1% 20k
75k 1%
5k
LTC1655
3
+ -
7 6 1k Q1 2N3440
LT(R)1077 3k 2 4
5V 10k CLK DIN CS/LD
RS 10 IOUT
1655/55L TA03
11
LTC1655/LTC1655L
TYPICAL APPLICATIONS
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 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.
P
TRANSFER CURVE 4.096 R3 100k 1% DIN R5 100k 1%
VOUT
0
32768
- 4.096
12
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A Wide Swing, Bipolar Output 16-Bit DAC
5V 0.1F 8 1 2 3 VCC CLK DIN CS/LD LTC1655 GND 5 VREF 6 R2 200k 1% VOUT 7 R1 100k 1% 5V 3
+ -
7 LT1077 6 VOUT: (2)(DIN)(4.096) - 4.096V 65536
2
4 R4 - 5V 200k 1%
1655/55L TA05
65535
LTC1655/LTC1655L
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.
1 P 2 3
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Digitally Programmable Current Source
5V 8 VCC CLK DIN CS/LD GND 5 LTC1655 VOUT 7 3 2 0.1F 5V < VS < 100V FOR RL 50 RL 6 Q1 2N3440 IOUT = (DIN)(4.096) (65536)(RA) 0mA TO 10mA
+ -
7
LT1218 4
RA 412 1%
1655/55L TA04
13
LTC1655/LTC1655L
PACKAGE DESCRIPTION U
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
0.255 0.015* (6.477 0.381)
1 0.300 - 0.325 (7.620 - 8.255)
2
3
4 0.130 0.005 (3.302 0.127)
0.045 - 0.065 (1.143 - 1.651)
0.009 - 0.015 (0.229 - 0.381)
0.065 (1.651) TYP 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 0.003 (0.457 0.076)
N8 1098
(
+0.035 0.325 -0.015 8.255 +0.889 -0.381
)
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)
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LTC1655/LTC1655L
PACKAGE DESCRIPTION
0.010 - 0.020 x 45 (0.254 - 0.508) 0.008 - 0.010 (0.203 - 0.254) 0- 8 TYP
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
0.016 - 0.050 (0.406 - 1.270)
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.
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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
0.228 - 0.244 (5.791 - 6.197)
0.150 - 0.157** (3.810 - 3.988)
1
2
3
4
0.053 - 0.069 (1.346 - 1.752)
0.004 - 0.010 (0.101 - 0.254)
0.050 (1.270) BSC
SO8 1298
15
LTC1655/LTC1655L
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.
RELATED PARTS
PART NUMBER LTC1257 LTC1446/ LTC1446L LTC1448 LTC1450/ LTC1450L LTC1451 LTC1452 LTC1453 LTC1454/ LTC1454L LTC1456 LTC1458/ LTC1458L LTC1650 LTC1654 LTC1657/ LTC1657L LTC1658 LTC1659 DESCRIPTION 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 Dual 12-Bit VOUT DACs in SO-8 Package Dual 12-Bit VOUT DAC, VCC: 2.7V to 5.5V Single 12-Bit VOUT DACs with Parallel Interface 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 Single Rail-to-Rail 12-Bit VOUT Multiplying DAC, VCC: 2.7V to 5.5V COMMENTS 5V to 15V Single Supply, Complete VOUT DAC 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 Output Swings from GND to REF. REF Input Can Be Tied to VCC LTC1450: VCC = 4.5V to 5.5V, VOUT = 0V to 4.095V LTC1450L: VCC = 2.7V to 5.5V, VOUT = 0V to 2.5V 5V, Low Power Complete VOUT DAC in SO-8 Package Low Power, Multiplying VOUT DAC with Rail-to-Rail Buffer Amplifier in SO-8 Package LTC1454: VCC = 4.5V to 5.5V, VOUT = 0V to 4.095V LTC1454L: VCC = 2.7V to 5.5V, VOUT = 0V to 2.5V Low Power, Complete VOUT DAC in SO-8 Package with Clear Pin LTC1458: VCC = 4.5V to 5.5V, VOUT = 0V to 4.095V LTC1458L: VCC = 2.7V to 5.5V, VOUT = 0V to 2.5V Low Power, Deglitched, 4-Quadrant Mulitplying VOUT DAC, Output Swing 4.5V 1LSB DNL, 2 DACs in SO-8 Footprint LTC1657: VCC = 5V, Low Power, Deglitched, VOUT = 0V to 4.096V LTC1657L: VCC = 3V, Low Power, Deglitched, VOUT = 0V to 2.5V Low Power, Multiplying VOUT DAC in MS8 Package. Output Swings from GND to REF. REF Input Can Be Tied to VCC Low Power, Multiplying VOUT DAC in MS8 Package. Output Swings from GND to REF. REF Input Can Be Tied to VCC
16555lf LT/TP 0800 4K * PRINTED IN USA
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 Dual 12-Bit VOUT DACs in SO-16 Package with Added Functionality Single Rail-to-Rail Output 12-Bit DAC with Clear Pin, Full Scale: 4.095V, VCC: 4.5V to 5.5V Quad 12 Bit Rail-to-Rail Output DACs with Added Functionality Single 16-Bit VOUT Industrial DAC in 16-Pin SO, VCC = 5V Dual 14-Bit DAC Single 16-Bit VOUT DAC with Parallel Interface Single Rail-to-Rail 14-Bit VOUT DAC in 8-Pin MSOP, VCC = 2.7V to 5.5V Single Rail-to-Rail 12-Bit VOUT DAC in 8-Pin MSOP, VCC = 2.7V to 5.5V
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Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 q FAX: (408) 434-0507 q www.linear-tech.com
U
Negative Offset Measurement
5V 0.1F 8 1 P 2 3 VCC CLK DIN CS/LD LTC1655/ LTC1655L GND 5 VOUT 7 R1 100k -5V
1655/55L TA06
(c) LINEAR TECHNOLOGY CORPORATION 1998

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