LTC7541A Improved Industry Standard CMOS 12-Bit Multiplying DAC U DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ The LTC® 7541A is a 12-bit resolution multiplying digitalto-analog converter (DAC). Improved Direct Replacement for AD7541A and AD7541 4-Quadrant Multiplication 12-Bit End-Point Linearity: ± 0.5LSB DNL and INL Over Temperature All Grades Guaranteed Monotonic Maximum Gain Error: ± 1LSB Single 5V to 15V Supply TTL and CMOS Logic Compatible Reduced Sensitivity to Op Amp Offset Low Power Consumption Virtually Latch-Up Proof Low Cost Laser-trimmed thin-film resistors provide excellent absolute accuracy. Precision matched resistors and CMOS circuitry result in remarkable stability with temperature and supply variations. The LTC7541A is a superior pin compatible replacement for the industry standard AD7541A/AD7541. Improvements include better typical accuracy and stability and reduced sensitivity to output amplifier offset. The LTC7541A is also very resistant to latch-up. In addition to 2-quadrant and 4-quadrant multiplying configurations, the LTC7541A performs well in digitally programmable gain and noninverting voltage output applications. Low cost, improved performance and versatility make the LTC7541A the best choice for many new designs and for upgrading existing systems. Parts are available in 18-pin PDIP and 18-pin SO Wide packages. U APPLICATIONS ■ ■ ■ ■ ■ Motion Control Systems Microprocessor-Controlled Calibration Automatic Test Equipment Programmable Gain Amplifiers Digitally Controlled Filters , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATION 2-Quadrant Multiplying DAC Has Less Than 0.5LSB (Typ) Total Unadjusted Error Integral Nonlinearity Over Temperature 1.0 VIN 0.1µF 17 16 VDD VREF 18 RFB 1 OUT 1 – LT ®1097 LTC7541A OUT 2 2 GND 4 TO 15 33pF + VOUT 3 INTEGRAL NONLINEARITY (LSB) 15V 0.5 TA = 85°C TA = 25°C 0 TA = –40°C –0.5 7541 TA01 DIGITAL INPUTS –1.0 0 512 1024 1536 2048 2560 3072 3584 4095 DIGITAL INPUT CODE 7541A TA02 1 LTC7541A U W U U W W W ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION VDD to GND ............................................... – 0.5V to 17V VREF to GND.......................................................... ±25V RFB to GND ........................................................... ±25V Digital Inputs to GND .................. – 0.5V to (VDD + 0.5V) OUT 1, OUT 2 to GND .................. – 0.5V to (VDD + 0.5V) Power Dissipation ............................................. 450mW (Derate 6mW/°C Above 75°C) Maximum Junction Temperature ......... – 65°C to 125°C Operating Temperature Range Commercial (J, K Versions).................. 0°C to 70°C Industrial (B Version) ...................... – 40°C to 85°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C ORDER PART NUMBER TOP VIEW OUT 1 1 18 RFB OUT 2 2 17 VREF GND 3 16 VDD BIT 1 (MSB) 4 15 BIT 12 (LSB) BIT 2 5 14 BIT 11 BIT 3 6 13 BIT 10 BIT 4 7 12 BIT 9 BIT 5 8 11 BIT 8 BIT 6 9 10 BIT 7 LTC7541ABN LTC7541ABSW LTC7541AJN LTC7541AKN LTC7541AJSW LTC7541AKSW SW PACKAGE 18-LEAD PLASTIC SO WIDE N PACKAGE 18-LEAD PDIP TJMAX = 150°C, θJA = 100°C/ W (N) TJMAX = 150°C, θJA = 130°C/ W (SW) Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS VDD = 15V, VREF = 10V, OUT 1 = OUT 2 = GND = 0V, TA = TMIN to TMAX, unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN LTC7541AJ TYP MAX LTC7541AK/LTC7541AB MIN TYP MAX UNITS Accuracy Resolution INL Integral Nonlinearity (Relative Accuracy) ● (Note 1) DNL Differential Nonlinearity Guaranteed Monotonic, TMIN to TMAX GE Gain Error (Note 2) Gain Temperature Coefficient (Note 3) Output Leakage Current (Note 4) ILKG PSRR Power Supply Rejection VDD = 15V ±5% 12 12 TA = 25°C TMIN to TMAX ±0.5 ● ±1 ±0.5 LSB ● ±6 ±8 ±1 ±2 LSB LSB 5 ppm/°C 1 ● TA = 25°C TMIN to TMAX Bits ±1 ● 5 1 ● ±5 ±10 ±5 ±10 ● ±0.002 ±0.002 LSB nA nA %/% Reference Input RREF VREF Input Resistance VREF Input Resistance Temperature Coefficient 2 ● 7 11 – 100 15 7 11 – 100 15 kΩ ppm/°C LTC7541A ELECTRICAL CHARACTERISTICS VDD = 15V, VREF = 10V, OUT 1 = OUT 2 = GND = 0V, TA = TMIN to TMAX, unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN ALL GRADES TYP MAX UNIT Power Supply VDD Operating Supply Range IDD Suppy Current 5 ● Digital Inputs = VIH or VIL Digital Inputs = 0V or VDD 15 ● ● 16 V 2 100 mA µA Digital Inputs VIH Digital Input High Voltage ● VIL Digital Input Low Voltage ● IIN Digital Input Current ● CIN Digital Input Capacitance (Note 3), VIN = 0V 2.4 V 0.001 0.8 V ±1 µA 8 pF ● AC Performance COUT Propagation Delay (Notes 5, 6) 100 ns Digital-to-Analog Glitch Impulse (Notes 5, 7) 1000 nV-sec Multiplying Feedthrough Error VREF = ±10V, 10kHz Sinewave 1.0 mVP-P Output Current Settling Time (Note 5), To 0.01% for Full-Scale Change 0.6 µs Output Capacitance (Note 3) Digital Inputs = VIH COUT1 COUT2 ● ● 200 70 pF pF Digital Inputs = VIL COUT1 COUT2 ● ● 70 200 pF pF The ● denotes specifications which apply over the full operating temperature range. Note 1: ±0.5LSB = ±0.012% of full scale. Note 2: Using internal feedback resistor. Note 3: Guaranteed by design, not subject to test. Note 4: IOUT1 with all digital inputs = 0V or IOUT2 with all digital inputs = VDD. Note 5: OUT 1 load = 100Ω in parallel with 13pF. Note 6: Measured from digital input change to 90% of final analog value. Digital inputs = 0V to VDD or VDD to 0V. Note 7: VREF = 0V. All digital inputs 0V to VDD or VDD to 0V. Measured using LT1363 as output amplifier. W BLOCK DIAGRAM 20k 20k 20k VREF RFB 40k 40k 40k 40k 40k 40k 40k 10k OUT 1 OUT 2 VDD DECODER TTL/DTL/CMOS COMPATIBLE DIGITAL INPUTS • • • • GND BIT 1 (MSB) BIT 2 BIT 3 BIT 4 BIT 12 (LSB) 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. 7541 BD 3 LTC7541A U TYPICAL APPLICATIONS N Unipolar Operation (2-Quadrant Multiplication) VREF – 10 TO 10V 15V 0.1µF 17 16 VDD VREF Table 1. Unipolar Binary Code Table 18 33pF RFB 1 OUT 1 DIGITAL INPUT LTC7541A + OUT 2 2 GND LT1097 VOUT 3 4 TO 15 ANALOG OUTPUT VOUT – MSB 1111 1000 0000 0000 1111 0000 0000 0000 LSB 1111 0000 0001 0000 –VREF (4095/4096) –VREF (2048/4096) = –VREF/ 2 –VREF (1/4096) 0V DIGITAL INPUTS 7541 TA03 Bipolar Operation (4-Quadrant Multiplication) R2 20k VREF – 10 TO 10V R3 20k 15V 0.1µF 17 16 VDD VREF 18 RFB 1 OUT 1 LTC7541A 33pF – R1 10k 1/2 LT1112 OUT 2 2 GND + – 1/2 LT1112 + VOUT 3 4 TO 15 DIGITAL INPUTS Table 2. Bipolar Offset Binary Code Table DIGITAL INPUT MSB 1111 1000 1000 0111 0000 1111 0000 0000 1111 0000 LSB 1111 0001 0000 1111 0000 ANALOG OUTPUT VOUT VREF (2047/2048) VREF (1/2048) 0V –VREF (1/2048) –VREF 7541 TA04 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC1257 Complete Serial I/O VOUT 12-Bit DAC 5V to 15V Single Supply in 8-Pin SO and PDIP LTC1451/LTC1452/LTC1453 Complete Serial I/O VOUT 12-Bit DACs 3V/5V Single Supply in 8-Pin SO and PDIP LTC7543/LTC8143 Serial I/O Muliplying 12-Bit DACs Clear Pin, Serial Data Output (LTC8143) LTC8043 Serial Mulitplying 12-Bit DAC 8-Pin SO and PDIP 4 Linear Technology Corporation LT/GP 1195 6K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 ● FAX: (408) 434-0507 ● TELEX: 499-3977 LINEAR TECHNOLOGY CORPORATION 1995