LTC1043 Dual Precision Instrumentation Switched Capacitor Building Block DESCRIPTIO U FEATURES ■ ■ ■ ■ ■ ■ ■ The LTC®1043 is a monolithic, charge-balanced, dual switched capacitor instrumentation building block. A pair of switches alternately connects an external capacitor to an input voltage and then connects the charged capacitor across an output port. The internal switches have a break-before-make action. An internal clock is provided and its frequency can be adjusted with an external capacitor. The LTC1043 can also be driven with an external CMOS clock. Instrumentation Front End with 120dB CMRR Precise, Charge-Balanced Switching Operates from 3V to 18V Internal or External Clock Operates up to 5MHz Clock Rate Low Power Two Independent Sections with One Clock U APPLICATIO S ■ ■ ■ ■ ■ The LTC1043, when used with low clock frequencies, provides ultra precision DC functions without requiring precise external components. Such functions are differential voltage to single-ended conversion, voltage inversion, voltage multiplication and division by 2, 3, 4, 5, etc. The LTC1043 can also be used for precise V–F and F–V circuits without trimming, and it is also a building block for switched capacitor filters, oscillators and modulators. Precision Instrumentation Amplifiers Ultra Precision Voltage Inverters, Multipliers and Dividers V–F and F–V Converters Sample-and-Hold Switched Capacitor Filters The LTC1043 is manufactured using Linear Technology’s enhanced LTCMOSTM silicon gate process. , LTC and LT are registered trademarks of Linear Technology Corporation. LTCMOS is a trademark of Linear Technology Corporation. U TYPICAL APPLICATIO Instrumentation Amplifier 5V 4 140 5V 3 8 1µF CH 11 1µF (EXTERNAL) CS + 1/2 LTC1013 2 – CS = CH = 1µF 120 8 1 VOUT 4 –5V 100 CMRR (dB) 7 DIFFERENTIAL INPUT CMRR vs Frequency 80 60 12 1µF 13 14 R1 16 1/2 LTC1043 0.01µF 17 LTC1043 • TA01 –5V R2 CMRR > 120dB AT DC CMRR > 120dB AT 60Hz DUAL SUPPLY OR SINGLE 5V GAIN = 1 + R2/R1 VOS ≈ 150µV 40 20 100 1k 10k 100k FREQUENCY OF COMMON MODE SIGNAL LTC1043 • TA02 ∆ VOS ≈ 2µV/°C ∆T COMMON MODE INPUT VOLTAGE INCLUDES THE SUPPLIES 1043fa 1 LTC1043 W W W AXI U U ABSOLUTE RATI GS U U W PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART NUMBER TOP VIEW Supply Voltage ........................................................ 18V Input Voltage at Any Pin .......... –0.3V ≤ VIN ≤ V+ + 0.3V Operating Temperature Range LTC1043C ................................... –40°C ≤ TA ≤ 85°C LTC1043M (OBSOLETE).............– 55°C ≤ TA ≤ 125°C Storage Temperature Range ................. –65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C SH B 1 18 S3B CB+ 2 17 V – CB– 3 16 COSC V+ 4 15 S4B S2B 5 14 S4A S1B 6 13 S3A S1A 7 12 CA– S2A 8 11 CA+ NC 9 10 SHA LTC1043CN LTC1043CSW N PACKAGE 18-LEAD PDIP SW PACKAGE 18-LEAD PLASTIC SO TJMAX = 100°C, θJA = 100°C/W PACKAGE (N) TJMAX = 150°C, θJA = 85°C/W PACKAGE (SW) LTC1043MD D PACKAGE 18-LEAD SIDE BRAZED (HERMETIC) OBSOLETE PACKAGE Consider the N18 Package as an Alternate Source LTC1043 • POI01 Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS + The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. V = 10V, V– = 0V, LTC1043M operates from –55°C ≤ TA ≤ 125°C; LTC1043C operates from –40°C ≤ TA ≤ 85°C, unless otherwise noted. SYMBOL PARAMETER IS Power Supply Current CONDITIONS MIN Pin 16 Connected High or Low LTC1043M TYP MAX OFF Leakage Current Any Switch, Test Circuit 1 (Note 2) ● RON RON fOSC IOSC ON Resistance ON Resistance Internal Oscillator Frequency Pin Source or Sink Current Test Circuit 2, VIN = 7V, 1 = ±0.5mA V+ = 10V, V – = 0V ● Test Circuit 2, VIN = 3.1V, 1 = ±0.5mA V + = 5V, V – = 0V ● COSC (Pin 16 to V –) = 0pF COSC (Pin 16 to V –) = 100pF Test Circuit 3 ● Pin 16 at V+ or V – 20 15 0.25 0.4 0.7 mA mA 0.4 0.65 1 0.4 0.65 1 mA mA 6 6 100 500 6 6 100 pA nA 240 400 700 240 400 700 Ω Ω 400 700 1 400 700 1 Ω kΩ 50 75 kHz kHz kHz 70 100 µA µA 185 34 40 ● Break-Before-Make Time UNITS 0.4 0.7 ● II LTC1043C TYP MAX 0.25 ● COSC (Pin 16 to V –) = 100pF MIN 50 75 70 100 20 15 185 34 40 25 25 ns Clock to Switching Delay COSC Pin Externally Driven 75 75 ns fM Max External CLK Frequency COSC Pin Externally Driven with CMOS Levels 5 5 MHz CMRR Common Mode Rejection Ratio V+ = 5V, V – = –5V, –5V < VCM < 5V DC to 400Hz 120 120 Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 2 dB Note 2: OFF leakage current is guaranteed but not tested at 25°C. 1043fa LTC1043 U W TYPICAL PERFOR A CE CHARACTERISTICS Power Supply Current vs Power Supply Voltage RON vs VIN 1.6 550 TA = –55°C COSC = 0pF 1.4 COSC = 0.0047pF RON vs VIN RON (PEAK) 500 I = 100µA 450 V IN 1.2 TA = 25°C COSC = 0pF 1.0 COSC = 0.0047pF 0.8 TA = 125°C COSC = 0pF 0.6 COSC = 0.0047pF 0.4 280 V+ = 5V V – = 0V TA = 25°C 0.2 V+ = 10V V – = 0V TA = 25°C RON (PEAK) 260 240 VIN I = 100µA 220 400 350 300 I = 100µA 250 200 RON (Ω) RON (Ω) SUPPLY CURRENT (mA) (Test Circuits 2 through 4) 180 I = 100µA 160 I = mA 200 140 150 120 100 100 I = mA 0 2 4 6 1 0 8 10 12 14 16 18 20 VSUPPLY (V) 3 2 4 LTC1043 • TPC01 180 160 I = 100µA 140 800 600 700 500 200 80 100 8 0 10 12 14 16 18 20 VIN (V) VIN ≈ 3.2V 400 300 6 VIN ≈ 7V 3V ≤ V+ + ≤18V V – = 0V TA = 25°C 0 2 4 6 250 225 VIN ≈ 15.1V fOSC (kHz) fOSC (Hz) TA = 125°C TA = 70°C TA = –55°C 200 100 8 10 12 14 16 18 20 VSUPPLY (V) 0 V+ = 15V, V – = 0V 2 4 6 8 10 12 14 16 18 20 VSUPPLY (V) LTC1043 • TPC06 Normalized Oscillator Frequency, fOSC vs Supply Voltage 2.0 COSC = 0pF 175 V+ = 10V, V – = 0V V+ = 5V, V – = 0V 150 125 100 75 1k 50 10 300 TA = 25°C 200 100k 9 500 Oscillator Frequency, fOSC vs Supply Voltage TA = 25°C 10k 600 LTC1043 • TPC05 Oscillator Frequency, fOSC vs COSC 8 I = 100µA VIN 400 VIN ≈ 11V LTC1043 • TPC04 1M 900 I = 100µA VIN 800 100 4 7 RON (PEAK) 1000 700 120 2 5 6 VIN (V) 1100 RON (PEAK) VIN = 1.6V 900 I = mA 0 4 RON (Peak) vs Power Supply Voltage and Temperature RON (Ω) I = 100µA 1000 RON (Ω) RON (Ω) 220 V IN 200 V+ = 15V V – = 0V TA = 25°C 3 LTC1043 • TPC03 RON (Peak) vs Power Supply Voltage RON (PEAK) 240 2 LTC1043 • TPC02 RON vs VIN 260 1 0 5 VIN (V) OSCILLATOR FREQUENCY NORMALIZED TO fOSC AT 5V SUPPLY 0 COSC = 100pF 25 0pF < COSC < 0.01µF TA = 25°C 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 100 0 2k 4k 6k COSC (pF) 8k 10k LTC1043 • TPC07 0 2 4 6 8 10 12 14 16 18 20 VSUPPLY (V) LTC1043 • TPC08 0 2 4 6 8 10 12 14 16 18 20 VSUPPLY (V) LTC1043 • TPC09 1043fa 3 LTC1043 U W TYPICAL PERFOR A CE CHARACTERISTICS Oscillator Frequency, fOSC vs Ambient Temperature, TA COSC Pin ISINK, ISOURCE vs Supply Voltage 350 fOSC (kHz) 275 250 225 200 V+ = 10V, V– = 0V 175 125 V+ – = 5V, V = 0V V+ = 15V, V– = 0V 100 50 25 0 75 100 –50 –25 AMBIENT TEMPERATURE (°C) 80 ISINK, TA = –55°C 75 60 ISINK, TA = 25°C ISOURCE, TA = –55°C 50 ISOURCE, TA = 25°C 50 40 30 25 ISINK, TA = 125°C 20 ISOURCE, TA = 125°C 0 0 125 TA = 25°C 70 tNOV (ns) 300 150 Break-Before-Make Time, tNOV, vs Supply Voltage 100 COSC = 0pF PIN 16 SOURCE OR SINK CURRENT (µA) 325 (Test Circuits 2 through 4) 2 4 6 8 10 12 14 16 10 18 0 LTC1043 • TPC11 LTC1043 • TPC10 2 4 6 8 10 12 14 16 18 20 VSUPPLY (V) LTC1043 • TPC12 W BLOCK DIAGRA S1A 7 S2A 8 SHA 10 11 CA+ 12 CA– S3A 13 S4A 14 CHARGE BALANCING CIRCUITRY S1B 6 SHB 1 S2B 5 2 CB+ 3 CB– S3B 18 S4B 15 CHARGE BALANCING CIRCUITRY NON-OVERLAPPING CLOCK V+ V– COSC 16 OSCILLATOR V+ 4 V– 17 THE CHARGE BALANCING CIRCUITRY SAMPLES THE VOLTAGE AT S3 WITH RESPECT TO S4 (PIN 16 HIGH) AND INJECTS A SMALL CHARGE AT THE C+ PIN (PIN 16 LOW). THIS BOOSTS THE CMRR WHEN THE LTC1043 IS USED AS AN INSTRUMENTATION AMPLIFIER FRONT END. FOR MINIMUM CHARGE INJECTION IN OTHER TYPES OF APPLICATIONS, S3A AND S3B SHOULD BE GROUNDED THE SWITCHES ARE TIMED AS SHOWN WITH PIN 16 HIGH LTC1043 • BD01 1043fa 4 LTC1043 TEST CIRCUITS Test Circuit 1. Leakage Current Test (7, 13, 6, 18) (7, 13, 6, 18) (8, 14, 5, 15) A 0V TO 10V Test Circuit 2. RON Test + (11, 12, 2, 3) NOTE: TO OPEN SWITCHES, S1 AND S3 SHOULD BE CONNECTED TO V –. TO OPEN S2, S4, COSC PIN SHOULD BE TO V+ COSC + (8, 14, 5, 15) VIN (11, 12, 2, 3) 100µA to 1mA CURRENT SOURCE LTC1043 • TC01 A LTC1043 • TC02 Test Circuit 3. Oscillator Frequency, fOSC Test Circuit 4. CMRR Test 7 V– (TEST PIN) 2 17 10 COSC V+ 4 + LTC1043 VOUT 8 11 + 16 1µF 1µF CAPACITORS ARE NOT ELECTROLYTIC 5 12 + 6 IV 13 14 LTC1043 • TC03 + V– ≤ VCM ≤ V+ CMRR = 20 LOG ( ) VCM VOUT NOTE: FOR OPTIMUM CMRR, THE COSC SHOULD BE LARGER THAN 0.0047µF, AND THE SAMPLING CAPACITOR ACROSS PINS 11 AND 12 SHOULD BE PLACED OVER A SHIELD TIED TO PIN 10 LTC1043 • TC04 U W U U APPLICATIO S I FOR ATIO Common Mode Rejection Ratio (CMRR) The LTC1043, when used as a differential to single-ended converter rejects common mode signals and preserves differential voltages (Figure 1). Unlike other techniques, the LTC1043’s CMRR does not degrade with increasing common mode voltage frequency. During the sampling mode, the impedance of Pins 2, 3 (and 11, 12) should be reasonably balanced, otherwise, common mode signals will appear differentially. The value of the CMRR depends on the value of the sampling and holding capacitors (CS, CH) and on the sampling frequency. Since the common mode voltages are not sampled, the common mode signal frequency can well exceed the sampling frequency without experiencing aliasing phenomena. The CMRR of Figure 1 is measured by 1/2 LTC1043 7 8 C+ 11 VD + + CS VD CH C– 12 13 VCM 14 + CS, CH ARE MYLAR OR POLYSTRENE LTC1043 • AI01 Figure 1. Differential to Single-Ended Converter 1043fa 5 LTC1043 U W U U APPLICATIO S I FOR ATIO shorting Pins 7 and 13 and by observing, with a precision DVM, the change of the voltage across CH with respect to an input CM voltage variation. During the sampling and holding mode, charges are being transferred and minute voltage transients will appear across the holding capacitor. Although the RON on the switches is low enough to allow fast settling, as the sampling frequency increases, the rate of charge transfer increases and the average voltage measured with a DVM across it will increase proportionally; this causes the CMRR of the sampled data system, as seen by a “continuous” instrument (DVM), to decrease (Figure 2). Switch Charge Injection Figure 3 shows one out of the eight switches of the LTC1043, configured as a basic sample-and-hold circuit. When the switch opens, a ‘‘hold step’’ is observed and its magnitude depends on the value of the input voltage. Figure 4 shows charge injected into the hold capacitor. For instance, a 2pCb of charge injected into a 0.01µF capacitor causes a 200µV hold step. As shown in Figure 4, there is a predictable and repeatable charge injection cancellation when the input voltage is close to half the supply voltage of the LTC1043. This is a unique feature of this product, containing charge-balanced switches fabricated with a self-aligning gate CMOS process. Any switch of the LTC1043, when powered with symmetrical dual supplies, will sample-and-hold small signals around ground without any significant error. Shielding the Sampling Capacitor for Very High CMRR Internal or external parasitic capacitors from the C + pin(s) to ground affect the CMRR of the LTC1043 (Figure 1). The common mode error due to the internal junction capacitances of the C + Pin(s) 2 and 11 is cancelled through internal circuitry. The C + pin, therefore, should be used as the top plate of the sampling capacitor. The interpin capacitance between pin 2 and dummy Pin 1 (11 and 10) appears in parallel with the sampling capacitor so it does not degrade the CMRR. A shield placed underneath the sampling capacitor and connected to either Pin 1 or 3 helps to boost the CMRR in excess of 120dB (Figure 5). Excessive external parasitic capacitance between the C – pins and ground indirectly degrades CMRR; this becomes visible especially when the LTC1043 is used with clock frequencies above 2kHz. Because of this, if a shield is used, the parasitic capacitance between the shield and circuit ground should be minimized. It is recommended that the outer plate of the sampling capacitor be connected to the C – pin(s). Input Pins, SCR Sensitivity An internal 60Ω resistor is connected in series with the input of the switches (Pins 5, 6, 7, 8, 13, 14, 15, 18) and it is included in the RON specification. When the input voltage exceeds the power supply by a diode drop, current will flow into the input pin(s). The LTC1043 will not latch until the input current reaches 2mA–3mA. The device will 140 120 CS = CH = 1µF 5V CS = 1µF, CZH = 0.1µF 2 + 6 CMRR (dB) 100 1/2 LTC1013 1/8 LTC1043 VOUT – 80 VIN 1000pF –5V 60 V+ 40 SAMPLE HOLD TO PIN 16 0V LTC1043 • AI03 20 100 1k 10k 100k fOSC (Hz) LTC1043 • AI02 Figure 2. CMRR vs Sampling Frequency Figure 3 1043fa 6 LTC1043 U W U U APPLICATIO S I FOR ATIO recover from the latch mode when the input drops 3V to 4V below the voltage value which caused the latch. For instance, if an external resistor of 200Ω is connected in series with an input pin, the input can be taken 1.3V above the supply without latching the IC. The same applies for the C + and C – pins. COSC Pin (16), Figure 6 The Cosc pin can be used with an external capacitor, Cosc, connected from Pin 16 to Pin 17, to modify the internal oscillator frequency. If Pin 16 is floating, the internal 24pF capacitor, plus any external interpin capacitance, set the oscillator frequency around 190kHz with ±5V supply. The typical performance characteristics curves provide the necessary information to set the oscillator frequency for various power supply ranges. Pin 16 can also be driven with an external clock to override the internal oscillator. Although standard 7400 series CMOS gates do not guarantee CMOS levels with the current source and sink requirements of Pin 16, they will in reality drive the Cosc pin. CMOS gates conforming to standard B series output drive have the appropriate voltage levels and more than enough output current to simultaneously drive several LTC1043 COSC pins. The typical trip levels of the Schmitt trigger (Figure 6) are given below. SUPPLY V+ = 5V, TRIP LEVELS V – = 0V VH = 3.4VVL = 1.35V V+ = 10V, V – = 0V VH = 6.5VVL = 2.8V V+ = 15V, V – = 0V VH = 9.5VVL = 4.1V 12 V+ = 15V V– = 0V CHARGE INJECTION (pCb) 10 8 V+ = 10V V– = 0V 6 1 OUTSIDE FOIL 4 V+ = 5V V– = 0V 2 CS 2 3 0 0 2 4 6 10 8 VIN (V) 12 14 PRINTED CIRCUIT BOARD AREA 16 LTC1043 LTC1043 • AI05 LTC1043 • AI04 Figure 5. Printed Circuit Board Layout Showing Shielding the Sampling Capacitor Figure 4. Individual Switch Charge Injection vs Input Voltage V+ 4 38µF COSC 16 COSC (EXTERNAL) TO CLK GENERATOR 24pF 17 fOSC = 190kHz • V– (24pF) (24pF + COSC) LTC1043 * AI06 Figure 6. Internal Oscillator 1043fa 7 LTC1043 U TYPICAL APPLICATIO S Divide by 2 Multiply by 2 Ultra Precision Voltage Inverter 1/2 LTC1043 1/2 LTC1043 VIN 1/2 LTC1043 7 8 VOUT VOUT = VIN /2 7 7 8 VOUT = –VIN 8 VIN 1µF 11 11 11 1µF 1µF 1µF 1µF 1µF 12 12 12 VIN 13 14 13 17 16 13 14 14 16 16 17 17 0.01µF 0.01µF 0.01µF VOUT = VIN /2 ± 1ppm 0 ≤ VIN ≤ V+ 3 ≤ V+ ≤ 18V VOUT = 2VIN ± 5ppm 0 ≤ VIN ≤ V+ /2 3 ≤ V+ ≤ 18V LTC1043 • A01 Precision Multiply by 3 VOUT = –VIN ±2ppm V – < VIN < V + V + = +5V, V – = –5V LTC1043 * A03 LTC1043 • A02 Precision Multiply by 4 Divide by 3 VIN LTC1043 LTC1043 LTC1043 7 8 7 11 8 VIN VIN 7 11 11 1µF 1µF 1µF 12 12 12 13 8 13 14 14 13 14 6 5 VOUT VOUT 2VIN 5 6 2 1µF 5 6 VOUT = 4VIN 1µF 2 2 1µF 1µF 1µF 3 18 1µF 1µF 1µF 3 3 15 18 VOUT 15 18 15 1µF 16 17 0.01µF VOUT = 3VIN ±10ppm 0 < VIN < V+/3 3V < V+ < 18V 17 16 16 LTC1043 • A04 VOUT = 4VIN ±40ppm 0 ≤ VIN ≤ V+/4 3V < V+ < 18V 17 0.01µF 0.01µF VOUT = VIN /3 ±3ppm 0 ≤ VIN ≤ V+ LTC1043 • A05 LTC1043 • A06 1043fa 8 LTC1043 U TYPICAL APPLICATIO S Divide by 4 0.005% V/F Converter –5V VIN 7 LT1009 2.5k 1k LTC1043 8 17 5V 1/2 LTC1043 11 8 1µF 1µF 7 1µF 12 11 fOUT: 0kHz TO 30kHz 14 13 13 14 4 VIN 0V TO 3V VOUT 5 6 6.19k 12 5V GAIN 2.5k 16 0.01µF – 1µF LF356 + 2 1µF 1µF –5V 3 30pF 22k 18 15 16 17 330k Q1 2N2907A 0.01µF 1µF –5V LTC1043 • A08 0 ≤ VIN ≤ V+ VOUT = VIN /4 ±5ppm LTC1043 • A07 0.01% Analog Multiplier 1/4 LTC1043 14 1k –5V 13 LT1004-1.2V 1µF 12 5V YINPUT 7.5k* 2 1µF – + † 80.6k* 0.01µF 6 16 4 XINPUT 30pF 6 2 5 – 7 LT1056 3 330k OPERATE LTC1043 FROM ±5V POLYSTYRENE, MOUNT CLOSE *1% FILM RESISTOR ADJUST OUTPUT TRIM SO X • Y = OUTPUT ±0.01% † 2N2907A (FOR START-UP) 1µF –5V 5V 1/4 LTC1043 –5V 22k 20k OUTPUT TRIM 7 LT1056 3 0.001µF 2 0.001µF † + 6 OUTPUT XY ±0.01% 4 –5V LTC1043 • A09 1043fa 9 LTC1043 U TYPICAL APPLICATIO S Voltage Controlled Current Source with Ground Referred Input and Output Single 5V Supply, Ultra Precision Instrumentation Amplifier 5V 5V + LTC1043 7 3 8 7 + 6 LTC1052 2 4 1µF INPUT 8 + 1/2 LT1013 OUTPUT AV = 1000 8 – 11 3 INPUT 0V TO 2V 2 – 1 4 1 0.1µF 0.1µF 1µF 0.68µF 12 – 99.9k 100Ω 13 5V 14 1k 4 V+ = 5V 43k 5 6 8 0.22µF 7 10k 2 11 1µF NONPOLARIZED 1µF 1N914 1µF 1µF 3 18 100Ω 12 15 14 ≈ –0.5V 13 1/2 LTC1043 16 17 4 INPUT AND OUTPUT VOLTAGE RANGE INCLUDES GROUND. INPUT REFERRED OFFSET ERRORS ARE TYPICALLY 3µV WITH 1µV OF NOISE CMRR ~ 120dB 5V 0.0047 1OUT = VIN 100Ω 16 17 0.001µF LTC1043 • A10 OPERATES FROM A SINGLE 5V SUPPLY LTC1043 • A11 Precision Instrumentation Amplifier 5V CHOPPER 4 1/2 LTC1043 + INPUT 6 AC AMPLIFIER 1/4 LTC1043 11 8 2 1µF 1µF 5V 1µF 7 5 PHASE SENSITIVE DEMODULATOR 3 1M 2 + 7 LT1056 – 1/4 LTC1043 1µF 6 13 100k 12 4 100k 2 – 100k 5V 7 LT1056 14 –5V DC OUTPUT AMPLIFIER 1µF 3 3 + 6 OUTPUT 4 –5V 100Ω – INPUT 18 15 16 17 0.01µF 0.01 –5V OFFSET = 10µV DRIFT = 0.1µV/°C FULL DIFFERENTIAL INPUT CMRR = 140dB OPEN LOOP GAIN > 10 8 GAIN = R2/R1 + 1 IBIAS = 1nA R2 100k R1 100Ω LTC1043 • A12 1043fa 10 LTC1043 U TYPICAL APPLICATIO S Lock-In Amplifier (= Extremely Narrow-Band Amplifier) THERMISTOR BRIDGE IS THE SIGNAL SOURCE SYNCHRONOUS DEMODULATOR 10k* 10k* T1 500Hz SINE DRIVE 4 1 6.19k 3 3 6.19k 2 RT 5V 5V 6.19k 2 + 1/4 LTC1043 6 LT1007 – 3 12 – 5V LM301A 13 + 2 8 1 100k 1M – LT1012 –5V 14 3 –5V 16 30pF + T1 = TF5SX17ZZ, TOROTEL RT = YSI THERMISTOR 44006 ≈ 6.19k AT 37.5°C *MATCH 0.05% 6.19k = VISHAY S-102 OPERATE LTC1043 WITH ±5V SUPPLIES 47µF PHASE TRIM 5V 0.002 4 –5V + 50k VOUT = 1000 • DC BRIDGE SIGNAL 1µF 100Ω 0.01µF 6 5V 10k 2 7 LT1011 3 – LOCK-IN AMPLIFIER TECHNIQUE USED TO EXTRACT VERY SMALL SIGNALS BURIED INTO NOISE 1k 8 + LTC1043 • A013 4 1 –5V ZERO CROSSING DETECTOR 50MHz Termal RMS/DC Converter 5V 5V 4 30k* 30k* 5V 1/2 LTC1043 6 3 5 8 + 10k LT1013 2 2 1µF 1µF 1µF 3 – 18 15 0.01µF 1µF 5V + LT1013 100k* 301Ω* 10k 6 – 7 DC OUTPUT 0V TO 3.5V 10k 10k 10k 17 BRN RED N CALIBRATION ADJUST 20k 5 16 0.01µF 300mV 10VRMS INPUT 4 1 RED T2 T2A 1A GRN T1B T2B *1% RESISTOR GRN 2% ACCURACY DC 50MHZ 100:1 CREST FACTOR CAPABILITY T1 TO T2 = YELLOW SPRINGS INST. CO. THERMISTOR COMPOSITE ENCLOSE T1 AND T2 IN STYROFOAM LTC1043 • A14 1043fa 11 LTC1043 U TYPICAL APPLICATIO S Quad Single 5V Supply, Low Hold Step, Sample-and-Hold 5V 2 1/4 LT1014 NC 7 3 8 13 4 – + 1 OUTPUT 1/4 LT1014 NC 11 6 14 OUTPUT + CL 0.01µF 2 VIN VIN 6 9 – 1/4 LT1014 NC 12 5 CL 0.01µF 11 – 13 5 14 7 OUTPUT 1/4 LT1014 + NC 18 10 15 CL 0.01µF 12 OUTPUT + VIN HOLD LTC1043 • A15 16 SAMPLE 8 CL 0.01µF 3 VIN – 17 4 – 5V FOR 1V ≤ VIN ≤ 4V, THE HOLD STEP IS ≤ 300µV ACQUISITION TIME ~ 8 • RON CH FOR 10-BIT ACCURACY LTC1043 • A16 Single Supply Precision Linearized Platinum RTD Signal Conditioner 250k* (LINEARITY CORRECTION LOOP) 5V 3 10k* + 8 1/2 LT1013 2 – 5V 2.4k 1 2.74k* 4 LT1009 2.5V 50k ZERO ADJUST 8.25k* 0.1µF 4 2k 1/2 LTC1043 7 0V TO 4V = 0°C TO 400°C ±0.05°C 1/2 LTC1043 8 5 5 6 + 1/2 LT1013 6 11 1µF 2 1µF 13 8.06k* 3 14 1mA Rp 100Ω AT 0°C 15 16 Rp = ROSEMOUNT 118MFRTD * 1% FILM RESISTOR TRIM SEQUENCE: SET SENSOR TO 0°C VALUE. ADJUST ZERO FOR 0V OUT SET SENSOR TO 100°C VALUE. ADJUST GAIN FOR 1,000V OUT SET SENSOR TO 400°C VALUE. ADJUST LINEARITY FOR 4,000V OUT REPEAT AS REQUIRED 5k 1µF 1µF 887Ω 12 – 7 1k GAIN ADJUST 18 1k* 17 0.01µF LTC1043 • A17 1043fa 12 LTC1043 U TYPICAL APPLICATIO S 0.005% F/V Converter 75k* 10k GAIN TRIM 1µF 1/4 LTC1043 1k 5V 13 –5V – 14 1µF LT1004-1.2C 12 –5V 1000pF FREQUENCY IN 0kHz TO 30kHz 0V TO 3V OUTPUT LF356 + 4 5V 17 –5V *75k = TRW # MTR-5/120ppm 16 LTC1043 • A18 High Frequency Clock Tunable Bandpass Filter R1 10k R2 10k 10k RIN VIN 5V – 1/2 LTC1043 LT1056 7 8 + –5V CLOCK INPUT 11 16 1000pF 200pF BANDPASS OUTPUT 12 5V 13 14 4 – 1/2 LTC1043 LT1056 RQ = 10k 5V 5 6 + –5V 2 1000pF 200pF 3 fCLK • BANDPASS CENTER FREQUENCY fO = 31.4 BANDPASS GAIN AT fO IS: RQ /RIN RQ R2 Q= R2 R1 fO MAX ≤ 100kHz QMAX AT 100kHz fO IS ≤10 (fO • Q) MAX ≤ 1MHz fCLK MAX ≤ 3MHz, Q < 2 R2 R1 5V 15 18 – LT1056 17 –5V + – 5V LTC1043 • A19 1043fa 13 LTC1043 U TYPICAL APPLICATIO S Frequency-Controlled Gain Amplifier 13A 1/2 LTC1043A 12A 16A GAIN CONTROL 0kHz TO 10kHz = GAIN 0 TO 1000 13B 1/2 LTC1043B 14A 14B 12B 16B 0.01µF 100pF 11A 11B 7A 7B 8A 8B VIN 5V 2 – 0.01µF 7 6 LT1056 3 FOR DIFFERENTIAL INPUT, GROUND PIN 8A AND USE PINS 13A AND 7A FOR INPUTS fIN • 0.01µF GAIN = ; GAIN IS NEGATIVE AS SHOWN 1kHz • 100pF FOR SINGLE-ENDED INPUT AND POSITIVE GAIN, GROUND PIN 8A AND USE PIN 7A FOR INPUT USE ± 5V SUPPLIES FOR LTC1043 + VOUT 4 –5V LTC1043 • A20 Relative Humidity Sensor Signal Conditioner 0.01µF 1/4 LTC1043 8 7 16 –5V 17 11 470k 100pF 1k* 500 90% RH TRIM 5V 1/4 LTC1043 13 2 14 – 7 LT1056 3 12 1µF + 4 –5V 1µF 6 10k 3 + 6 LM301A 2 8 – OUTPUT 0V TO 1V = 0% TO 100% 1 LT1004 1.2V SENSOR 9k* 22M 100pF 10k 5% RH TRIM 33k * = 1% FILM RESISTOR SENSOR = PANAMETRICS # RHS ≈ 500pF AT RH = 76% 1.7 pF/%RH 1k* LTC1043 • A21 1043fa 14 LTC1043 U TYPICAL APPLICATIO S Linear Variable Differential Transformer (LVDT), Signal Conditioner 1/4 LTC1043 0.005µF 0.005µF 30k 7 5V 5V 30k 3 4 11 8 + 1.5kHz 1 LT1013 2 8 RD-BLUE YEL-BLK – 4 100k 5 – 5V BLUE GRN AMPLITUDE STABLE SINE WAVE SOURCE 6 10k 1N914 4.7k LT1004 1.2V Q1 2N4338 1.2k + 1/2 LT1013 1µF – 10µF OUTPUT 0V ±2.5V 0M 2.50M 200k YEL-RED BLK 10k GAIN TRIM LVDT + 7 12 7.5k –5V 17 13 14 1/4 LTC1043 LVDT = SCHAEVITZ E-100 5V 100k 5V 0.01µF 3 100k PHASE TRIM 1k 8 + 7 LT1011 2 TO PIN 16, LTC1043 1 – 4 –5V LTC1043 • A22 Precision Current Sensing in Supply Rails IIN SHUNT CAN BE IN POSITIVE OR NEGATIVE SUPPLY LEAD RSHUNT 1/2 LTC1043 7 VOUT 8 11 + 1µF 1µF 12 13 14 16 17 0.01µF LTC1043 • A23 1043fa 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. 15 LTC1043 U PACKAGE DESCRIPTIO D Package 18-Lead Side Brazed (Hermetic) (Reference LTC DWG # 05-08-1210) .165 (4.191) MAX .485 (12.319) MAX .020 – .060 (0.508 – 1.524) .910 (23.114) MAX .005 (0.127) MIN 17 18 16 15 14 13 12 11 10 .290 (7.366) TYP .008 – .015 (0.203 – 0.381) .100 (2.54) BSC .125 (3.175) MIN .300 (7.620) REF PIN NO. 1 IDENT .054 (1.372) TYP .015 – .023 (0.381 – 0.584) 3 2 1 4 5 7 6 8 9 D18 0801 OBSOLETE PACKAGE N Package 18-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .900* (22.860) MAX 18 17 16 15 14 .130 ± .005 (3.302 ± 0.127) .300 – .325 (7.620 – 8.255) 13 12 11 10 .045 – .065 (1.143 – 1.651) .020 (0.508) MIN .065 (1.651) TYP .008 – .015 (0.203 – 0.381) .255 ± .015* (6.477 ± 0.381) +.035 .325 –.015 1 2 3 5 4 6 8 7 ( 9 8.255 +0.889 –0.381 .120 (3.048) MIN ) .005 (0.127) MIN .018 ± .003 (0.457 ± 0.076) .100 (2.54) BSC NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) N18 1002 SW Package 18-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .030 ±.005 TYP .447 – .463 (11.354 – 11.760) NOTE 4 N 18 17 16 15 14 13 12 11 10 N .325 ±.005 .420 MIN .394 – .419 (10.007 – 10.643) NOTE 3 1 2 3 N/2 NOTE: 1. DIMENSIONS IN N/2 RECOMMENDED SOLDER PAD LAYOUT .005 (0.127) RAD MIN .009 – .013 (0.229 – 0.330) .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) 1 3 .093 – .104 (2.362 – 2.642) 0° – 8° TYP .050 (1.270) BSC NOTE 3 .016 – .050 (0.406 – 1.270) 16 2 Linear Technology Corporation .014 – .019 (0.356 – 0.482) TYP 4 5 6 7 8 9 .037 – .045 (0.940 – 1.143) INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) .004 – .012 (0.102 – 0.305) S18 (WIDE) 0502 1043fa LW/TP 1202 1K REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 1985