LTC6943HGN#PBF

LTC6943 Micropower, Dual Precision Instrumentation Switched Capacitor Building Block DESCRIPTIO U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ Low Power, IS = 60µA(Max) Robust, Latch Up Proof Instrumentation Front End with 120dB CMRR Precise, Charge-Balanced Switching Operates from 5V to 18V Internal or External Clock Operates up to 5MHz Clock Rate Two Independent Sections with One Clock Tiny SSOP-16 Package U APPLICATIO S ■ ■ ■ ■ ■ Ultra Precision Voltage Inverters, Multipliers and Dividers V–F and F–V Converters Sample-and-Hold Current Sources Precision Instrumentation Amplifiers , LTC and LT are registered trademarks of Linear Technology Corporation. LTCMOS is a trademark of Linear Technology Corporation. The LTC®6943 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 LTC6943 can also be driven with an external CMOS clock. The LTC6943, 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 LTC6943 is manufactured using Linear Technology’s enhanced LTCMOSTM silicon gate process, and it is functionally compatible with the LTC1043. U TYPICAL APPLICATIO Precision Voltage Controlled Current Source with Ground Referred Input and Output Precision Current Sensing in Supply Rails 5V INPUT 0V TO 3.7V 3 + 4 – 5 1 LTC2050 POSITIVE OR NEGATIVE RAIL 2 I E RSHUNT 0.68µF 1/2 LTC6943 11 5V 1k 12 3 10 1/2 LTC6943 7 6 1µF 9 1µF 1µF E I= E RSHUNT 9 1k 1µF 10 6 12 11 15 14 IOUT = VIN 1000Ω 7 14 15 0.01µF 0.001µF OPERATES FROM A SINGLE 5V SUPPLY 6943 • TA01b 6943 • TA01a 6943f 1 LTC6943 W W W AXI U U ABSOLUTE RATI GS U U W PACKAGE/ORDER I FOR ATIO (Note 1) Supply Voltage ........................................................ 18V Input Voltage at Any Pin .......... –0.3V ≤ VIN ≤ V+ + 0.3V Operating Temperature Range (Note 2) ............................................ –40°C to 125°C Specified Temperature Range (Note 2) .............................................–40°C to 125°C Storage Temperature Range ................. –65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C ORDER PART NUMBER TOP VIEW CB+ 1 16 S3B CB– 2 15 V– V+ 3 LTC6943CGN LTC6943IGN LTC6943HGN 14 COSC S2B 4 13 S4B S1B 5 12 S4A S1A 6 11 S3A S2A 7 10 CA– SHA 8 9 GN PART MARKING CA+ 6943C 6943I 6943H GN PACKAGE 16-LEAD NARROW PLASTIC SSOP TJMAX = 125°C, θJA = 110°C/W 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 SYMBOL PARAMETER CONDITIONS IS Pin 14 Connected High or Low Power Supply Current LTC6943C LTC6943I MIN TYP MAX II OFF Leakage Current RON ON Resistance RON ON Resistance fOSC Internal Oscillator Frequency IOSC Pin Source or Sink Current ● Test Circuit 2, VIN = 3.1V, 1 = ±0.5mA V + = 5V, V – = 0V ● COSC (Pin 14 to V –) = 0pF COSC (Pin 14 to V –) = 100pF Test Circuit 3 ● Pin 14 at V+ or V – Clock to Switching Delay CMRR 60 90 µA µA 80 150 170 80 150 170 µA µA 6 100 40 6 100 200 pA nA 240 400 700 240 400 700 Ω Ω 400 700 1 400 700 1 Ω kΩ 20 12 50 75 kHz kHz kHz 70 100 µA µA 185 30 40 ● Break-Before-Make Time fM 40 ● Test Circuit 2, VIN = 7V, 1 = ±0.5mA V+ = 10V, V – = 0V COSC Pin Externally Driven Maximum External CLK Frequency COSC Pin Externally Driven with CMOS Levels Common Mode Rejection Ratio V+ = 5V, V – = –5V, –5V < VCM < 5V UNITS 60 90 ● Any Switch, Test Circuit 1 (Note 3) LTC6943H TYP MAX 40 ● COSC (Pin 14 to V –) = 100pF MIN 50 75 70 100 20 10 185 30 40 25 25 ns 75 75 ns 5 5 MHz 120 120 dB DC to 400Hz Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: All versions of the LTC6943 are guaranteed functional over the operating temperature range of –40°C to 125°C. The LTC6943CGN is guaranteed to meet 0°C to 70°C specifications and is designed, characterized and expected to meet the specified performance from –40°C to 85°C but it is not tested or QA sampled at these temperatures. The LTC6943IGN is guaranteed to meet specified performance from –40°C to 85°C. The LTC6943HGN is guaranteed to meet specified performance from –40°C to 125°C. Note 3: OFF leakage current at 25°C is guaranteed by design and it is not 100% tested in production. 6943f 2 LTC6943 U W TYPICAL PERFOR A CE CHARACTERISTICS Power Supply Current vs Power Supply Voltage COSC = 0pF, TA = –55°C COSC = 0pF, TA = 25°C COSC = 0pF, TA = 125°C COSC = 4700pF, TA = –55°C COSC = 4700pF, TA = 25°C COSC = 4700pF, TA = 125°C 0.45 0.40 0.35 RON vs VIN I = 100µA 450 V IN 280 V+ = 5V V – = 0V TA = 25°C RON (PEAK) 500 0.30 0.25 0.20 V+ = 10V V – = 0V TA = 25°C RON (PEAK) 260 240 VIN I = 100µA 220 400 RON (Ω) SUPPLY CURRENT (mA) RON vs VIN 550 350 300 I = 100µA 250 200 RON (Ω) 0.50 (Test Circuits 2 through 4) 180 I = 100µA 160 I = mA 0.15 200 140 0.10 150 120 0.05 100 100 I = mA 0 2 4 6 8 10 12 VSUPPLY (V) 14 16 18 1 0 3 2 4 6943 TPC01 I = 100µA 180 160 I = 100µA 140 1000 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 VIN ≈ 15.1V fOSC (kHz) IOSC (kHz) VS = 5V VS = 10V COSC = 0pF 150 125 100 COSC = 100pF 25 0 0.1 4000 0 5000 6943 TPC07 2 4 8 10 12 14 16 18 20 VSUPPLY (V) 6 LTC1043 • TPC06 1.5 50 2000 3000 COSC (pF) TA = –55°C Normalized Oscillator Frequency, fOSC vs Supply Voltage 75 VS = 15V 1000 100 8 10 12 14 16 18 20 VSUPPLY (V) 175 0 TA = 70°C 200 200 100 1 TA = 125°C 300 TA = 25°C 225 0 2 4 6 10 12 VSUPPLY (V) 8 14 10 500 Oscillator Frequency, fOSC vs Supply Voltage TA = 25°C 10 600 LTC1043 • TPC05 Oscillator Frequency, fOSC vs COSC 9 I = 100µA VIN 400 VIN ≈ 11V LTC1043 • TPC04 1000 900 I = 100µA VIN 800 100 4 8 7 RON (PEAK) 1000 700 120 2 1100 RON (PEAK) VIN = 1.6V 900 I = mA 0 5 6 VIN (V) 4 RON (Peak) vs Power Supply Voltage and Temperature RON (Ω) V+ = 15V V – = 0V TA = 25°C RON (Ω) RON (Ω) 220 V IN 200 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 16 18 6943 TPC08 TA = 25°C 1.3 COSC = 0pF 1.0 COSC = 100pF 0.5 COSC = 10,000pF COSC = 1,000pF 0.3 0 0 2 4 6 8 10 12 VSUPPLY (V) 14 16 18 6943 TPC09 6943f 3 LTC6943 U W TYPICAL PERFOR A CE CHARACTERISTICS Oscillator Frequency, fOSC vs Ambient Temperature COSC Pin ISINK, ISOURCE vs Supply Voltage 100 PIN 14 SOURCE OR SINK CURRENT (µA) COSC = 0pF 300 VS = 5V fOSC (kHz) 250 200 150 VS = 10V VS = 15V 100 50 0 –50 –25 Break-Before-Make Time, tNOV, vs Supply Voltage 80 ISINK, TA = –55°C 70 ISINK, TA = 25°C 60 ISOURCE, TA = –55°C 50 ISOURCE, TA = 25°C 100 ISINK, TA = 125°C 40 20 ISOURCE, TA = 125°C 0 125 50 30 25 0 50 25 75 0 TEMPERATURE (°C) TA = 25°C 75 tNOV (ns) 350 (Test Circuits 2 through 4) 2 4 6 8 10 12 14 16 18 LTC1043 • TPC11 6943 TPC10 10 0 2 4 6 8 10 12 14 16 18 20 VSUPPLY (V) LTC1043 • TPC12 W BLOCK DIAGRA 7 S2A S1A 6 SHA 8 9 CA+ 10 CA– 12 S4A S3A 11 CHARGE BALANCING CIRCUITRY S1B 5 4 S2B 1 CB+ 2 CB– S3B 16 13 S4B CHARGE BALANCING CIRCUITRY NON-OVERLAPPING CLOCK 3 V+ OSCILLATOR 15 V– V+ V– COSC 14 THE CHARGE BALANCING CIRCUITRY SAMPLES THE VOLTAGE AT S3 WITH RESPECT TO S4 (PIN 14 HIGH) AND INJECTS A SMALL CHARGE AT THE C+ PIN (PIN 14 LOW). THIS BOOSTS THE CMRR WHEN THE LTC6943 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 14 HIGH 6943 • BD01 6943f 4 LTC6943 TEST CIRCUITS Test Circuit 1. Leakage Current Test Test Circuit 2. RON Test (6, 11, 5, 16) (6, 11, 5, 16) A 0V TO 10V (7, 12, 4, 13) (7, 12, 4, 13) + (9, 10, 1, 2) NOTE: TO OPEN SWITCHES, S1 AND S3 PIN 14, SHOULD BE CONNECTED TO V –. TO OPEN S2, S4, THE COSC PIN 14 SHOULD BE CONNECTED TO V+ COSC + VIN (9, 10, 1, 2) 100µA to 1mA CURRENT SOURCE 6943 • TC01 A 6943 • TC02 Test Circuit 4. CMRR Test Test Circuit 3. Oscillator Frequency, fOSC 6 V– (TEST PIN) 1 V+ 3 + LTC6943 COSC VOUT 7 15 8 9 14 1µF 1µF CAPACITORS ARE NOT ELECTROLYTIC 4 10 + 5 IV 11 6943 • TC03 + 12 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 9 AND 10 SHOULD BE PLACED OVER A SHIELD TIED TO PIN 8 6943 • TC04 U W U U APPLICATIO S I FOR ATIO Common Mode Rejection Ratio (CMRR) The LTC6943, when used as a differential to single-ended converter rejects common mode signals and preserves differential voltages (Figure 1). Unlike other techniques, the LTC6943’s CMRR does not degrade with increasing common mode voltage frequency. During the sampling mode, the impedance of Pins 1, 2 (and 9, 10) should be 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 shorting Pins 6 and 11 and by observing, with a 1/2 LTC6943 6 7 C+ VD 9 + + CS VD CH C– 10 11 VCM 12 + CS, CH ARE MYLAR OR POLYPROPYLENE 6943 • AI01 Figure 1. Differential to Single-Ended Converter 6943f 5 LTC6943 U W U U APPLICATIO S I FOR ATIO 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 LTC6943, 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 LTC6943. This is a unique feature of this product, containing charge-balanced switches fabricated with a self-aligning gate CMOS process. Any switch of the LTC6943, when powered with symmetrical dual supplies, will sample-and-hold small signals around ground without any significant error. 140 120 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 LTC6943 (Figure 1). The common mode error due to the internal junction capacitances of the C + Pin(s) 1 and 9 is cancelled through internal circuitry. The C + pin, therefore, should be used as the top plate of the sampling capacitor. A shield placed underneath the sampling capacitor and connected to C – helps to boost the CMRR to 120dB (Figure 5). Excessive external parasitic capacitance between the C – pins and ground indirectly degrades CMRR; this becomes visible especially when the LTC6943 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). COSC Pin (14) The COSC pin can be used with an external capacitor, COSC, connected from Pin 14 to Pin 15, 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 14 can also be driven with an external CMOS level clock to override the internal oscillator. CS = CH = 1µF CS = 1µF, CH = 0.1µF 5V CMRR (dB) 100 1 80 + 5 VOUT 1/2 LTC1013 1/8 LTC6943 – 60 VIN 1000pF –5V 40 V+ 20 100 SAMPLE HOLD TO PIN 14 1k 10k 100k 0V 6943 • AI03 fOSC (Hz) 6943 • AI02 Figure 2. CMRR vs Sampling Frequency Figure 3 6943f 6 LTC6943 U W U U APPLICATIO S I FOR ATIO 12 V+ = 15V V– = 0V CHARGE INJECTION (pCb) 10 8 V+ = 10V V– = 0V 6 OUTSIDE FOIL CS 4 1 2 V+ = 5V V– = 0V 2 PRINTED CIRCUIT BOARD AREA LTC6943 6943 • AI05 0 0 2 6 4 10 8 VIN (V) 12 14 16 6943 • AI04 Figure 5. Printed Circuit Board Layout Showing Shielding the Sampling Capacitor Figure 4. Individual Switch Charge Injection vs Input Voltage U TYPICAL APPLICATIO S Divide by 2 Multiply by 2 Ultra Precision Voltage Inverter 1/2 LTC6943 1/2 LTC6943 VIN 6 1/2 LTC6943 7 VOUT = VIN /2 VOUT 6 6 7 VOUT = –VIN 7 VIN 1µF 9 9 9 1µF 1µF 1µF 1µF 1µF 10 10 10 VIN 11 12 11 12 14 15 14 15 11 12 14 0.01µF VOUT = VIN /2 ± 1ppm 0 ≤ VIN ≤ V+ 3 ≤ V+ ≤ 18V 15 0.01µF 0.01µF 6943 • TA03 VOUT = 2VIN ± 5ppm 0 ≤ VIN ≤ V+ /2 3 ≤ V+ ≤ 18V VOUT = –VIN ±2ppm V – < VIN < V + V + = +5V, V – = –5V 6943 • TA02 6943 • TA03 6943f 7 LTC6943 U TYPICAL APPLICATIO S Precision Multiply by 3 Divide by 3 VIN LTC6943 VIN LTC6943 6 6 7 7 9 9 1µF 1µF 10 10 11 11 12 5 4 12 VOUT 1µF VOUT 4 5 2 2 1µF 1µF 1µF 1µF 3 3 VOUT 16 13 14 15 16 13 1µF 14 15 0.01µF 0.01µF VOUT = 3VIN ±10ppm 0 < VIN < V+/3 3V < V+ < 18V VOUT = VIN /3 ±3ppm 0 ≤ VIN ≤ V+ 6943 • TA07 6943 • TA06 0.01% V/F Converter –5V LT1009 2.5V 1k 15 5V 1/2 LTC6943 7 6 1µF 9 fOUT: 0kHz TO 30kHz 12 3 VIN 0V TO 3V 10 14 5V GAIN 2.5k 6.19k** 11 2 – 1µF LT1056 3 + 0.01µF* 7 4 6 *POLYPROPYLENE **1% FILM RESISTOR –5V 22k Q1 2N2907A –5V 30pF 330k 1µF 6943 • TA08 6943f 8 LTC6943 U TYPICAL APPLICATIO S 0.01% Analog Multiplier 1/4 LTC6943 1k 12 –5V 11 1µF LT1004-1.2V 20k OUTPUT TRIM 10 5V YINPUT 7.5k* 2 0.001µF 3 80.6k* 7 – + 0.01µF 6 LT1056 1µF † 14 4 5V 1/4 LTC6943 –5V XINPUT 5 2 4 7 – LT1056 30pF 3 330k 22k 1 OPERATE LTC6943 FROM ±5V † POLYPROPYLENE, MOUNT CLOSE *1% FILM RESISTOR ADJUST OUTPUT TRIM SO X • Y = OUTPUT ±0.01% 2N2907A (FOR START-UP) 1µF –5V 0.001µF + † 6 OUTPUT XY ±0.01% 4 –5V 6943 • TA09 Single 5V Supply, Ultra Precision Low Power with True Rail-to-Rail In/Out Instrumentation Amplifier 5V + LTC6943 6 3 7 + 5 LTC2054CS 4 9 1µF INPUT – 1 OUTPUT AV = 1000 2 1µF 10 – V+ = 5V 99.9k 100Ω 11 12 5 4 43k 0.22µF 10k 1 1µF NONPOLARIZED 1µF 1N914 2 16 13 ≈ –0.5V 14 15 3 5V 0.0047 INPUT AND OUTPUT VOLTAGE RANGE INCLUDES GROUND. INPUT REFERRED OFFSET ERRORS ARE TYPICALLY 3µV WITH 2µV OF PEAK-TO-PEAK DC TO 10Hz NOISE CMRR ~ 120dB 6943 • TA10 6943f 9 LTC6943 U TYPICAL APPLICATIO S Voltage Controlled Current Source with Ground Referred Input and Output 5V 3 INPUT 0V TO 2V 8 + 1 1/2 LT1013 2 – 4 0.68µF 5V 1k 3 7 6 9 1µF 1µF 100Ω 10 12 11 1/2 LTC6943 IOUT = VIN 100Ω 14 15 0.001µF OPERATES FROM A SINGLE 5V SUPPLY 6943 • TA11 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 RT 5V 5V 6.19k 6.19k 2 2 + 1/4 LTC6943 6 LT1007 – 10 – 5V LT1056 11 3 2 + 1M 100k LT1012 –5V –5V 12 – 3 14 + 6 VOUT = 1000 • DC BRIDGE SIGNAL 4 1µF 100Ω + 0.01µF 47µF PHASE TRIM 50k 10k 5V 0.002 –5V T1 = TF5SX17ZZ, TOROTEL RT = YSI THERMISTOR 44006 ≈ 6.19k AT 37.5°C *MATCH 0.05% 6.19k = VISHAY S-102 OPERATE LTC6943 WITH ±5V SUPPLIES 5V 2 1k 8 + 7 LT1011 3 – LOCK-IN AMPLIFIER TECHNIQUE USED TO EXTRACT VERY SMALL SIGNALS BURIED INTO NOISE 6943 • TA13 4 1 –5V ZERO CROSSING DETECTOR 6943f 10 LTC6943 U TYPICAL APPLICATIO S 50MHz Thermal RMS/DC Converter 5V 5V 3 30k** 30k** 5V 1/2 LTC6943 5 3 4 + 10k 8 1 LT1013 2 1 1µF – 1µF 1µF CALIBRATION ADJUST 20k 5 + LT1013 100k* 4 5V 6 7 – 10k 14 2 0.01µF 301Ω* 10k 16 13 10k 0.01µF 10k 1µF 300mV– 10VRMS INPUT DC OUTPUT 0V TO 3.5V 15 BRN RED BRN RED T1 T2 GRN GRN 2% ACCURACY DC-50MHZ 100:1 CREST FACTOR CAPABILITY T1 – T2 = YELLOW SPRINGS INST. CO. THERMISTOR COMPOSITE ENCLOSE T1 AND T2 IN STYROFOAM *1% RESISTOR **0.1% RESISTOR 6943 • TA13 Single Supply Precision Linearized Platinum RTD Signal Conditioner 250k* (LINEARITY CORRECTION LOOP) 5V 3 10k* + 8 1/2 LT1013 2 – 5V 2.4k 1 LT1009 2.5V 2.74k* 4 50k ZERO ADJUST 8.25k* 0.1µF 3 2k 1/2 LTC6943 6 0V TO 4V = 0°C TO 400°C ±0.05°C 1/2 LTC6943 7 4 5 5 + 1/2 LT1013 6 9 1µF 1 11 1mA Rp 100Ω AT 0°C 13 16 14 15 0.01µF 5k LINEARITY ADJUST 8.06k* 2 12 1k GAIN ADJUST 1µF 1µF 887Ω* 1µF 10 – 7 1k* 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 1000V OUT SET SENSOR TO 400°C VALUE. ADJUST LINEARITY FOR 4000V OUT 6943 • TA14 REPEAT AS REQUIRED 6943f 11 LTC6943 U TYPICAL APPLICATIO S 0.01% F/V Converter 10k GAIN TRIM 75k* 1µF 1/4 LTC6943 1k 5V 11 –5V LT1004-1.2C 2 12 7 – 6 LT1056 1µF 3 + 10 0V TO 3V OUTPUT 4 –5V 1000pF** FREQUENCY IN 0kHz TO 30kHz 14 3 5V 15 –5V * 1% FILM RESISTOR ** POLYPROPYLENE 6943 • TA15 Frequency-Controlled Gain Amplifier 11A 1/2 LTC6943A GAIN CONTROL 0kHz TO 10kHz = GAIN 0 TO 1000 11B 1/2 LTC6943B 12A 10A 14A 10B 14B 0.01µF 1kHz 100pF 9A 6A 9B 7A 3 5V 12B 6B 7B 15 –5V VIN FOR DIFFERENTIAL INPUT, GROUND PIN 7A AND USE PINS 11A AND 6A 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 OPERATES THE LTC6943'S WITH ±5V SUPPLIES 5V 2 – LT1056 3 + 0.01µF 7 6 VOUT 4 –5V 6943 • TA16 6943f 12 LTC6943 U TYPICAL APPLICATIO S Battery Powered Relative Humidity Sensor Signal Conditioner 0.1 ≤ +9 100pF +9 4.7k 5% TRIM 10k 2.32k* 3 2 16 15 13 4 5 0.1 1.8k* LT1004 1.2V 1 LTC6943 90% TRIM 10pF≤ 500Ω 11 12 +9 10 – 0.1µF SENSOR RESPONSE RH% 5 25 50 75 90 A1 LT1006 + 0.1 CAPACITANCE 22M SENSOR 379.3pF 413.3pF 455.8pF 498.3pF 523.8pF OUTPUT 0-1.00V = 0-100% RH 9 6 * = 1% FILM RESISTOR ≤ = POLYPROPYLENE SENSOR = PANAMETRICS TYPE RHS 500pF AT RH = 76% 1.7pF/RH 7 6943 TA17 5V Powered, Frequency Output, Relative Humidity Sensor Signal Conditioner 80.6k* OUT LTC1799 1N4148 4V LTC6943 14 6 4V 15 S 4V 10 CHARGE PUMP 1µF L A1 LTC1050 + 100k RH = 25% TRIM (204.5pF) LT1634 4V RESET COMPARATOR – 562k* TO ALL 4V POINTS Q1 VN2222L 5V 12 5V 200Ω 4V 1000pF † 1µF 11 D 3 SENSOR 1k* CLOCK 10k BAT85 5V 7 9 0.1µF 10k 5V O1 VIN GND 125kHz 13.3k* RSET INTEGRATOR 300k* 4V C1 +V LT1671 – 4V 1N5712 110k* * = 1% METAL FILM RESISTOR † = WIMA, TYPE MKP-2 SENSOR = PANAMETRICS MC-2 0% RH = 196.7pF 100% RH = 227.8pF 0.31pF/RH 5V + 300pF Q Q OUT 0% TO 100% RH = 0Hz TO 1kHz 20k RH = 100% TRIM (227.8pF) 6943 TA20 6943f 13 LTC6943 U TYPICAL APPLICATIO S Linear Variable Differential Transformer (LVDT), Signal Conditioner 0.005µF 1/4 LTC6943 0.005µF 30k 6 5V 30k 3 5V 3 8 + 9 LT1013 2 7 1.5kHz 1 RD-BLUE YEL-BLK – 4 – 5V AMPLITUDE STABLE SINE WAVE SOURCE BLUE GRN 100k 10k 5 1N914 4.7k LT1004 1.2V Q1 2N4338 YEL-RED BLK + 1/2 LT1013 1µF 6 LVDT – 7 OUTPUT 0V ±2.5V 0mm ±2.50mm 200k 10 1.2k 10µF 7.5k –5V 15 11 10k GAIN TRIM 12 1/4 LTC6943 LVDT = SCHAEVITZ E-100 5V 100k 5V 0.01µF 3 100k PHASE TRIM 1k 8 + 7 LT1011 2 TO PIN 14, LTC6943 1 – 4 –5V +15V 1 500k 549k* ∆VBE Based Thermometer Requires No Calibration 5 49.9k* Q1 2N3906 1M 6943 • TA18 10k +15 LTC6943 C1 1µF + 16 2 Q2 TEMPERATURE SENSOR TRANSISTOR C2 1µF 13 14 A1 LTC1150 0-10VOUT = 0-100°C, 1°C ACCURACY – 0.01 C3 0.1 +15 10k *0.1% FILM RESISTOR SENSOR TRANSISTOR MAY BE ANY SMALL SIGNAL NPN-2N2222, 3904, ETC. DO NOT USE GOLD DOPED TRANSISTORS. 86k* 1M* 2.019k* LT1009 2.5V 6943 TA21 6943f 14 LTC6943 U PACKAGE DESCRIPTIO GN Package 16-Lead Plastic SSOP (Narrow .150 Inch) (Reference LTC DWG # 05-08-1641) .189 – .196* (4.801 – 4.978) .045 ±.005 16 15 14 13 12 11 10 9 .254 MIN .009 (0.229) REF .150 – .165 .229 – .244 (5.817 – 6.198) .0165 ± .0015 .150 – .157** (3.810 – 3.988) .0250 TYP RECOMMENDED SOLDER PAD LAYOUT 1 .015 ± .004 × 45° (0.38 ± 0.10) .007 – .0098 (0.178 – 0.249) 2 3 4 5 6 7 .053 – .068 (1.351 – 1.727) 8 .004 – .0098 (0.102 – 0.249) 0° – 8° TYP .016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) .008 – .012 (0.203 – 0.305) .0250 (0.635) BSC 3. DRAWING NOT TO SCALE *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 GN16 (SSOP) 0502 6943f 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 LTC6943 U TYPICAL APPLICATIO S 5V Powered Voltage-to-Frequency Converter 5VIN fOUT 0kHz TO 13 3kHz 2 16 3 LTC6943 15 22k 4 5 1 + LT1034 1.2V 22µF C1** 0.01 µF 2 13 16 14 10k FULL SCALE TRIM INPUT 0V TO 2V 5VIN 75k* – 1µF A1 1/2 LT1017 + 1N5712 50k D1 1N4148 C2 560pF 120pF 1.6M (10Hz TRIM) 6943 TA19 10k * = 1% FILM RESISTOR, TYPE TRW-MTR+120ppm/°C ** = POLYPROPYLENE RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC1043 Dual Precision Instrumentation Switched Cap, Building Block 120dB CMRR, 3V to 18V Operation LTC1152 Rail-to-Rail In/Out, Zero Drift Op Amp Operates Up to 14V Supply Voltage LTC2050 Zero Drift Op Amp Single Supply Operation on 2.7V to 11V, SOT-23 Package LTC2051 Zero Drift Dual Op Amp Dual LTC2050, 8-Lead DFN, MS8 Packages LTC2052 Zero Drift Quad Op Amp Dual LTC2050, GN16 Package LTC2053 Precision, Rail-to-Rail Zero Drift I.A. 120dB CMRR at Low Gains LTC2054 Low Power, Zero Drift Op Amp 150µA Supply Current, SOT-23 Package LTC6800 Low Cost, Rail-to-Rail I.A. VOS(MAX) = 100µV, DFN 8 Package LTC6915 Precision Instrumentation Amplifier with Digitally Programmable Gain 14 Levels of Programmable Gain, 125dB CMRR 6943f 16 Linear Technology Corporation LT/TP 0804 1K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2004