LTC1040

LTC1040 Dual Micropower Comparator FEATURES s s DESCRIPTIO s s s s s Micropower 1.5µW (1 Sample/Second) Power Supply Flexibility Single Supply 2.8V to 16V Split Supply ± 2.8V to ± 8V Guaranteed Max Offset 0.75mV Guaranteed Max Tracking Error Between Input Pairs ± 0.1% Input Common Mode Range to Both Supply Rails TTL/CMOS Compatible with ± 5V or Single 5V Supply Input Errors are Stable with Time and Temperature The LTC®1040 is a monolithic CMOS dual comparator manufactured using Linear Technology’s enhanced LTCMOSTM silicon gate process. Extremely low operating power levels are achieved by internally switching the comparator ON for short periods of time. The CMOS output logic holds the output information continuously while not consuming any power. In addition to switching power ON, a switched output is provided to drive external loads during the comparator’s active time. This allows not only low comparator power, but low total system power. Sampling is controlled by an external strobe input or an internal oscillator. The oscillator frequency is set by an external RC network. Each comparator has a unique input structure, giving two differential inputs. The output of the comparator will be high if the algebraic sum of the inputs is positive and low if the algebraic sum of the inputs is negative. , LTC and LT are registered trademarks of Linear Technology Corporation. LTCMOS™ is a trademark of Linear Technology Corporation. APPLICATIO S s s s s Battery-Powered Systems Remote Sensing Window Comparator BANG-BANG Controllers TYPICAL APPLICATIO Window Comparator with Symmetric Window Limits 1000 Typical LTC1040 Supply Current vs Sampling Frequency VS = ±5V LTC1040 A OUT = “1” WHEN VIN > VC + ∆ COMP A SUPPLY CURRENT, IS (µA) VIN + – + – 100 10 A + B = “1” WHEN VC – ∆ ≤ VIN ≤ VC + ∆ VC ∆ 1 REXT = 10M + – + – COMP B B OUT = “1” WHEN VIN < VC – ∆ 0.10 0.01 0.1 1 100 1,000 10 SAMPLING FREQUENCY, fS (Hz) LTC1040 • TA01 U EXTERNALLY STROBED 10,000 LTC1040 • TA02 U U 1040fa 1 LTC1040 ABSOLUTE (Note 1) AXI U RATI GS PACKAGE/ORDER I FOR ATIO TOP VIEW STROBE ON/OFF A+B A OUT A1+ A1– A2+ A2 – Total Supply Voltage (V+ to V –) ............................... 18V lnput Voltage ........................ (V+ + 0.3V) to (V – – 0.3V) Operating Temperature Range LTC1040C ..................................... – 40°C ≤ TA ≤ 85°C LTC1040M (OBSOLETE) .................... – 55°C to 125°C Storage Temperature Range ................. – 55°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C Output Short-Circuit Duration .......................Continuous 1 2 3 4 5 6 7 8 9 18 V+ 17 VP-P 16 OSC 15 BOUT 14 B1+ 13 B1– 12 B2+ 11 B2– 10 V– SW PACKAGE 18-LEAD PLASTIC SO WIDE ORDER PART NUMBER LTC1040CN LTC1040CSW GND N PACKAGE 18-LEAD PDIP TJMAX = 110°C, θJA = 120°C/W (N) TJMAX = 125°C, θJA = 85°C/W (SW) J PACKAGE 18-LEAD CERDIP TJMAX = 150°C, θJA = 80°C/W LTC1040MJ LTC1040CJ OBSOLETE PACKAGE Consider the N18 Package as an Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS SYMBOL VOS PARAMETER Offset Voltage (Note 2) The q denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. Test conditions: V+ = 5V, V – = – 5V, unless otherwise noted. CONDITIONS Split Supplies ± 2.8V to ± 6V Single Supply (V – = GND) 2.8V to 6V Split Supplies ± 6V to ± 8V Single Supply (V – = GND) 6V to 15V Tracking Error Between Input Pairs (Notes 2 and 3) Split Supplies ± 2.8V to ± 8V Single Supplies (V – = GND) 2.8 to 16V OSC = GND fS = 1kHz (Note 4) Split Supplies Single Supplies (V – = GND) V + = 5V, VP-P On V+ = 5V, VP-P Off LTC1040C LTC1040M q q q q q q q q q q MIN LTC1040M/LTC1040C TYP MAX ± 0.3 ±1 0.05 ± 0.3 ± 0.75 ± 4.5 0.1 UNITS mV mV % nA MΩ IBIAS RIN CMR PSR IS(ON) IS(OFF) tD Input Bias Current Average Input Resistance Common Mode Range Power Supply Range Power Supply ON Current (Note 5) Power Supply OFF Current (Note 5) Response Time (Note 6) A, B, A + B and ON/OFF Outputs (Note 7) Logic “1” Output Voltage Logic “0” Output Voltage 20 V– ± 2.8 2.8 30 V+ ±8 16 1.2 0.001 0.001 3 0.5 5 100 60 80 VOH VOL V + = 4.75V, lOUT = – 360µA V + = 4.75V, lOUT = 1.6mA q q 2.4 4.4 0.25 0.4 2 U V V V mA µA µA µs V V 1040fa W U U WW W LTC1040 ELECTRICAL CHARACTERISTICS SYMBOL VIH VIL REXT fS PARAMETER STROBE Input (Note 7) Logic “1” Input Voltage Logic “0” Input Voltage External Timing Resistor Sampling Frequency The q denotes the specifications which apply over the full operating temperature range otherwise specifications are at TA = 25°C. Test conditions: V+ = 5V, V – = – 5V, unless otherwise specified CONDITIONS V + = 5.25V V + = 4.75V Resistor Tied Between V + and OSC Pin REXT = 1M, CEXT = 0.1µF q q MIN 2.0 100 LTC1040M/LTC1040C TYP MAX 1.6 1.0 5 UNITS V V kΩ Hz 0.8 10,000 Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Applies over input voltage range limit and includes gain uncertainty. Note 3: Tracking error = (VIN1 – VIN2)/ VIN1. Note 4: RIN is guaranteed by design and is not tested. RIN = 1/(fS • 33pF). Note 5: Average supply current = tD • lS(ON) • fS + (1 – tD x fS) • lS(OFF). Note 6: Response time is set by an internal oscillator and is independent of overdrive voltage. Note 7: Inputs and outputs also capable of meeting EIA/JEDEC B series CMOS specifications. TYPICAL PERFOR A CE CHARACTERISTICS Peak Supply Current vs Supply Voltage 20 NORMALIZED SAMPLING FREQUENCY (fS/fS AT 5V, 25°C) 18 16 14 TA = 125°C SAMPLE RATE, fS (Hz) IS(ON) (mA) 12 10 8 6 4 2 0 2 4 10 8 6 12 SUPPLY VOLTAGE, V+ (V) 125°C –55°C 25°C LTC1040 • TPC01 Response Time vs Supply Voltage AVERAGE INPUT RESISTANCE, RIN (1/fS • 33pF) (Ω) 300 250 TA = 25°C 1011 TYPICAL OUTPUT VOLTAGE DROP, V+ –VP-P (V) RESPONSE TIME, tD (µs) 200 150 100 50 0 2 4 10 14 8 12 6 SUPPLY VOLTAGE, V+ (V) 16 UW 14 16 LTL1040 • TPC04 Normalized Sampling Frequency vs Supply Voltage and Temperature 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 TA = – 55°C 0 2 8 10 12 4 6 SUPPLY VOLTAGE, V+ (V) 14 16 TA = 25°C Sampling Rate vs REXT, CEXT 103 CEXT = 1000pF 102 CEXT = 0.01µF CEXT = 0.05µF 10 CEXT = 0.1µF 1 CEXT = 1µF R = 1M C = 0.1µF 0.1 100k 1M REXT (Ω) 10M LT1040 • TPC03 LTC1040 • TPC02 Input Resistance vs Sampling Frequency 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 VP-P Output Voltage vs Load Current 1010 V+ = 10V V+ = 2.8V V+ = 16V 109 108 V+ = 5V 107 1 10 102 103 SAMPLING FREQUENCY, fS (Hz) 104 0 1 2 345678 LOAD CURRENT, IL (mA) 9 10 LTC1040 • TPC05 LTC1040 • TPC06 1040fa 3 LTC1040 TYPICAL PERFOR A CE CHARACTERISTICS Response Time vs Temperature 130 120 RESPONSE TIME, t D (µs) V+ = 5V 110 100 90 80 70 60 50 40 –50 0 25 –25 50 75 100 AMBIENT TEMPERATURE, TA (°C) 125 9 LTC1040 TEST CIRCUIT VIN BLOCK DIAGRA 4 UW LTC1040 • TPC07 Quick Hookup Guide Self-Oscillating 1 18 17 16 V+ EXTERNAL STROBE INPUT 1 External Strobe 18 17 16 V+ REXT CEXT LTC1040 10 9 10 LTC1040 • TPC08 V+ (18) + – + – GND (9) V– (10) OUTPUT ALL INPUTS ON OPPOSITE COMPARATOR AT GROUND LTC1040 • TA01 W VIN1 A1+ 5 A1– 6 VIN2 A2+ 7 A2– 8 V+ 18 + – + – COMP A 4 4 AOUT 2 ON/OFF VIN1 B1+ 14 B1– 13 B2+ 12 B2– 11 VIN2 + – + – 3 A+B COMP B 15 BOUT 4 TIMING SWITCH GENERATOR TIMING STROBE 1 OSC 16 V+ POWER ON VP-P CIRCUIT 17 VP-P 80µs 9 GND 10 V– 1040fa LTC1040 • BD01 LTC1040 APPLICATIO S I FOR ATIO The LTC1040 uses sampled data techniques to achieve its unique characteristics. Some of the experience acquired using classic linear comparators does not apply to this circuit, so a brief description of internal operation is essential to proper application. The most obvious difference between the LTC1040 and other comparators is the dual differential input structure. Functionally, when the sum of inputs is positive, the comparator output is high and when the sum of the inputs is negative, the output is low. This unique input structure is achieved with CMOS switches and a precision capacitor array. Because of the switching nature of the inputs, the concept of input current and input impedance needs to be examined. The equivalent input circuit is shown in Figure 1. Here, the input is being driven by a resistive source, RS, with a bypass capacitor, CS. The bypass capacitor may or may not be needed, depending on the size of the source resistance and the magnitude of the input voltage, VIN. CIN ≈ 33pF RS VIN CS S1 + S2 – V– LTC1040 DIFFERENTIAL INPUT LTC1040 • AI01 Figure 1. Equivalent Input Circuit For RS < 1Ok Assuming CS is zero, the input capacitor, CIN, charges to VIN with a time constant of RS CIN. When RS is too large, CIN does not have a chance to fully charge during the sampling interval (≈ 80µs) and errors will result. If RS exceeds 10kΩ, a bypass capacitor is necessary to minimize errors. U For RS > 1OkΩ For RS greater than 10kΩ, CIN cannot fully charge and a bypass capacitor, CS, is needed. When switch S1 closes, charge is shared between CS and CIN. The change in voltage on CS because of this charge sharing is: CIN CIN + CS This represents an error and can be made arbitrarily small by increasing CS. ∆V = VIN • With the addition of CS, a second error term caused by the finite input resistance of the LTC1040 must be considered. Switches S1 and S2 alternately open and close, charging and discharging CIN between VIN and ground. The alternate charge and discharge of CIN causes a current to flow into the positive input and out of the negative input. The magnitude of this current is: IIN = q • fS = VIN CIN fS where fS is the sampling frequency. Because the input current is directly proportional to input voltage, the LTC1040 can be said to have an average input resistance of: RIN = VIN 1 1 = = IIN fS CIN fS • 33pF (see typical curve of Input Resistance vs Sampling Frequency). A voltage divider is set up between RS and RIN causing error. The input voltage error caused by these two effects is: CIN RS + VERROR = VIN CIN + CS RS + RIN W UU ( ) Example: fS = 10Hz, RS = 1MΩ, CS = 1µF, VIN = 1V VERROR = 1V 10 ( 33 •• 10 –12 + 106 +106• 109 ) –6 1 3 = 33µV + 330µV = 363µV. Notice that most of the error is caused by RIN. If the sampling frequency is reduced to 1Hz, the voltage error is reduced to 66µV. 1040fa 5 LTC1040 APPLICATIO S I FOR ATIO Minimizing Comparison Errors The two differential input voltages, V1 and V2, are converted to charge by the input capacitors CIN1 and CIN2 (see Figure 2). The charge is summed at the virtual ground point; if the net charge is positive, the comparator output is high and if negative, it is low. There is an optimum way to connect these inputs, in a specific application, to minimize error. S1 CIN1 + V1 VIRTUAL GROUND – + V2 S2 CIN2 – LTC1040 DUAL DIFFERENTIAL INPUT LTC1040 • AI02 Figure 2. Dual Differential Equivalent Input Circuit Ignoring internal offset, the LTC1040 will be at its switching point when: V1 • CIN1 + V2 • CIN2 = 0. Optimum error will be achieved when the differential voltages, V1 and V2, are individually minimized. Figure 3 shows two ways to connect the LTC1040 to compare an input voltage, VIN, to a reference voltage, VREF. Using the above equation, each method will be at null when: (a) (VREF – 0V) CIN1 – (0V – VIN) CIN2 = 0 or VIN = VREF (CIN1/CIN2) (b) (VREF – VIN) CIN1 – (0V – 0V) CIN2 = 0 or VIN = VREF. Notice that in method (a) the null point depends on the ratio of CIN1/CIN2, but method (b) is independent of this ratio. Also, because method (b) has zero differential input voltage, the errors due to finite input resistance are negligible. The LTC1040 has a high accuracy capacitor array and even the non-optimum connection will only result in ± 0.1% more error, worst-case compared to the optimum connection. 6 U Tracking Error Tracking error is caused by the ratio error between CIN1 and CIN2 and is expressed as a percentage. For example, consider Figure 3a with VREF = 1V. Then at null, VIN = VREF CIN1 = 1V ± 1mV CIN2 because CIN1 is guaranteed to equal CIN2 to within 0.1%. VREF VIN W UU + – + – VREF VIN + – + – (a) OK (b) Optimum LTC1040 • TA03 Figure 3. Two Ways to Do It Common Mode Range The input switches of the LTC1040 are capable of switching to either the V + or V – supply. This means that the input common mode range includes both supply rails. Many applications, not feasible with conventional comparators, are possible with the LTC1040. In the load current detector shown in Figure 4, a 0.1Ω resistor is used to sense the current in the V + supply. This application requires the dual differential input and common mode capabilities of the LTC1040. IL 0.1Ω + VS 100mV – + 1/2 – LTC1040 + RL OUT OUT = HI IF IL > 1A OUT = LO IF IL < 1A LTC1040 • AI04 Figure 4. Load Current Detector 1040fa LTC1040 APPLICATIO S I FOR ATIO Offset Voltage Error The errors due to offset, common mode, power supply variation, gain and temperature are all included in the offset voltage specification. This makes it easy to compute the error when using the LTC1040. Example: error computation for Figure 4. Assume: 2.8V ≤ VS ≤ 6V. Then total worst-case error is: IL (ERROR) = ± (100mV • 0.001 + 0.5mV) • ↑ ↑ Tracking Error VOS 6mA IL (ERROR)% = • 100 = ± 0.6%. 1A 1A = ± 6mA 100mV Note: If source resistance exceeds 10k, bypass capacitors should be used and the associated errors must be included. Pulsed Power (VP-P) Output It is often desirable to use comparators with resistive networks such as bridges. Because of the extremely low power consumption of the LTC1040, the power consumed by these resistive networks can far exceed that of the device itself. At low sample rates the LTC1040 spends most of its time off. To take advantage of this, a pulsed power (VP-P) output is provided. VP-P is switched to V + when the comparator is on and to a high impedance (open circuit) when the comparator is off. The ON time is nominally 80µs. Figure 5 shows the VP-P output circuit. V+ 18 Q1 P1 80µs COMPARATOR ON TIME 9 GND 17 VP-P LTC1040 • AI05 Figure 5. VP-P Output Switch U The VP-P output voltage is not precise (see VP-P Output Voltage versus Load Current curve). There are two ways VP-P can be used to power external networks without excessive errors: (1) ratiometric networks and (2) fast settling references. In a ratiometric network, the inputs are all proportional to VP-P (see Figure 6). Consequently, for small changes, the absolute value of VP-P does not affect accuracy. It is critical that the inputs to the LTC1040 completely settle within 4µs of the start of the comparison cycle and that they do not change during the 80µs ON time. When driving resistive networks with VP-P, capacitive loading on VP-P OUTPUT W UU – VIN + VTRIP + – 1/2 + LTC1040 – OUTPUT LTC1040 • AI06 Figure 6. Ratiometric Network Driven by VP-P the network should be minimized to meet the 4µs settling time requirement. It is not recommended that VP-P be used to drive networks with source impedances, as seen by the inputs, of greater than 10kΩ. In applications where an absolute reference is required, the VP-P output can be used to drive a fast settling reference. The LT1009 2.5V reference, ideal in this application, settles in approximately 2µs (see Figure 7). The current through R1 must be large enough to supply the LT1009 minimum bias current (≈1mA) and the load current, IL. VP-P OUTPUT R1 R2 LT1009 IL VIN R3 + – 1/2 + LTC1040 – LTC1040 • AI07 Figure 7. Driving Reference with VP-P Output 1040fa 7 LTC1040 APPLICATIO S I FOR ATIO Output Logic In addition to the normal outputs (AOUT and BOUT), two additional outputs, A + B and ON/0FF, are provided (see Figure 8 and Table 1). All logic is powered from V+ and ground, thus input and output logic levels are independent of the V – supply. The LTC1040 is directly compatible with CMOS logic and is TTL compatible for 4.75V ≤ V + ≤ 5.25V. No external pull-up resistors are required. Table 1. Output Logic Truth Table ΣA INPUTS + + – – ΣB INPUTS + – + – AOUT H H L L BOUT H L H L A+B L L L H ON/OFF L L H I* *I = indeterminate. When both A and B outputs are low, the ON/OFF output remains in the state it was in prior to entering AOUT = BOUT = L. Using External Strobe A positive pulse on the strobe input, with the 0SC input tied to ground, will initiate a comparison cycle. The STROBE input is edge-sensitive and pulse widths of 50ns will typically trigger the device. COMPARATOR A OUTPUT D C Q 4 3 D C Q 15 BOUT LTC1040 • AI09 COMPARATOR B OUTPUT STROBE 80µs Figure 8. LTC1040 Logic Diagram 8 U Because of the sampling nature of the LTC1040, some sensitivity exists between the offset voltage and the falling edge of the input strobe. When the falling edge of the strobe signal falls within the comparator’s active time (80µs after rising edge), offset changes of as much as 2mV can occur. To eliminate this problem, make sure the strobe pulse width is greater than the response time, tD. Using Internal Strobe An internal oscillator allows the LTC1040 to strobe itself. The frequency of oscillation, and hence sampling rate, is set by an external RC network (see typical curve of Sampling Rate vs REXT, CEXT). For self-oscillation, the STROBE pin must be tied to ground. The external RC network is connected as shown in Figure 9. To assure oscillation, REXT must be between 100k and 10M. There is no limit to the size of CEXT. REXT i s very important in determining the power consumption. The average voltage at the oscillator pin is approximately V +/2. The power consumed by REXT is then: PREXT = (V +/2)2/REXT. 1 2 ON/OFF W UU 18 17 16 V+ REXT CEXT LTC1040 A OUT A+B 9 10 Figure 9. External RC Connection Example: REXT = 1M, V + 5V, PREXT = (2.5)2/106 = 6.25 • 10–6W. LTC1040 • AI08 This is about four times the power consumed by the LTC1040 at V + = 5V and fS = 1 sample/second. Where power is a premium REXT should be made as large as possible. Note that the power consumed by REXT is not a function of fS or CEXT. 1040fa LTC1040 TYPICAL APPLICATIO S Complete Heating/Cooling Automatic Thermostat 5V AT 0.85µA † THERMISTOR # 44007 YELLOW SPRINGS INSTRUMENT CO., INC. SEPARATION (20mV) * HYSTERESIS = 5V • 82k = 20mV 20M 28°C TEMPERATURE SEPARATION 27°C HEAT COOL TIME LTC1040 • TA04 Window Comparator with Independent Window Limits and Fully Floating Differential Input LTC1040 VIN VU + – + – COMP A VL + – + – COMP B U † 17 20M 4.32k 4.99k LTC1040 5 6 7 8 82k* 5k TEMP ADJUST 6.81k 18 + – + – COMP A 4 3 HEAT 14 13 12 11 82k* + – + – COMP B 15 10M 16 COOL 9 20M 10 0.1µF LTC1040 • TA03 AIRCONDITIONING ON HYSTERESIS AIRCONDITIONING OFF HEATER OFF HYSTERESIS HEATER ON Hysteresis Comparator with Fully Floating Differential Input V+ VIN A OUT = “1” WHEN VIN > VU VTRIP R1 10k * + –1/2 LTC1040 + – OUT A+B = “1” WHEN VU ≥ VIN ≥ VL B OUT = “1” WHEN VIN < VL R2 2.49MΩ V R2 + (5V) R1 OUT = “0” WHEN VIN > VU = TRIP = 0.996 VTRIP + 20mV R1 + R2 OUT = “1” WHEN VIN < V1 = VTRIP R2 R1 + R2 = 0.996VTRIP LTC1040 • TA05 * TO CENTER HYSTERESIS ABOUT VTRIP, FORCE THIS INPUT TO HYSTERESIS/2 (10mV) LTC1040 • TA06 1040fa 9 LTC1040 TYPICAL APPLICATIO S The LTC1040 as a Linear Amplifier With a simple RC filter, the LTC1040 can be made to function as a linear amplifier. By filtering the logic output and feeding it back to the negative input, the loop forces the output duty cycle [tON/(tON + tOFF)] so that VOUT equals VIN (Figure 10). The RC time constant is set to keep the ripple on the output small. The maximum output ripple is: ∆V = V +/fSRC and V+ VIN + – LTC1040 1/2 + – R VOUT 2-Wire 0°C to 100°C Temperature Transducer with 4mA to 20mA Output V+ LM134 V– R 12V TO 40V 0°C = 4mA 100°C = 20mA 6 LT1019-5 4 18k † YELLOW 10 U should be set to 0.5mV to 1mV for best results. Notice that the higher the sampling frequency, fS, the lower RC can be. This is important because the RC filter also sets the loop response. A convenient way to keep fS as high as possible under all conditions is to connect a 100k resistor to pin 16 (OSC) with no capacitance to ground. V+ 0V C t ON LTC1040 • TA07 t OFF VOUT = V+ tON tON + tOFF LTC1040 • TA08 Figure 10. The LTC1040 as a Linear Amplifier 43 1N914 430Ω 3200 6250 1k ZERO ADJUST 6 5 7 8 100k 16 † † – + 1/2 – LTC1040 + 10 18 9 4 1M 2N6657 + 1µF 50Ω 10µF SPRINGS INSTRUMENT PART NO. 44201 + 5k FULL-SCALE ADJUST 182Ω RETURN ACCURACY = ±0.1°C + = ±0.3°C ±0.2°C CIRCUIT ERROR TRANSDUCER AT 25°C ERROR LTC1040 • TA09 1040fa LTC1040 PACKAGE DESCRIPTIO CORNER LEADS OPTION (4 PLCS) .023 – .045 (0.584 – 1.143) HALF LEAD OPTION .045 – .065 (1.143 – 1.650) FULL LEAD OPTION .300 BSC (7.62 BSC) .015 – .060 (0.380 – 1.520) .008 – .018 (0.203 – 0.457) 0° – 15° NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) ( +.035 .325 –.015 8.255 +0.889 –0.381 ) INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) NOTE: 1. DIMENSIONS ARE 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. U J Package 18-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) .960 (24.384) MAX 18 17 16 15 14 13 12 11 10 .005 (0.127) MIN .025 (0.635) RAD TYP 1 2 3 4 5 6 7 8 9 .200 (5.080) MAX .220 – .310 (5.590 – 7.870) .125 (3.175) MIN .045 – .065 (1.143 – 1.651) .014 – .026 (0.360 – 0.660) .100 (2.54) BSC J18 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 13 12 11 10 .255 ± .015* (6.477 ± 0.381) 1 .130 ± .005 (3.302 ± 0.127) .020 (0.508) MIN 2 3 4 5 6 7 8 9 .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .120 (3.048) MIN .005 (0.127) MIN .018 ± .003 (0.457 ± 0.076) .100 (2.54) BSC N18 1002 1040fa 11 LTC1040 TYPICAL APPLICATIO S Analog Multiplier/Divider 5V 4 VC 100k 3 V1 V2 VA 5 6 7 8 16 10k VOUT 10µF 18 15 VIN 5 6 7 8 + – 1/2 + LTC1040 – 9 18 10 4 16 LTC1043 VB* 13 17 VOUT = (VA + V1 – V2) • VC VB ACCURACY = ±10mV NO TRIM * VB MUST BE > VA + (V1 – V2) LTC1040 • TA10 PACKAGE DESCRIPTIO .030 ±.005 TYP N .420 MIN 1 2 RECOMMENDED SOLDER PAD LAYOUT .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) 0° – 8° TYP 1 .093 – .104 (2.362 – 2.642) 2 3 4 5 6 7 8 9 .037 – .045 (0.940 – 1.143) .005 (0.127) RAD MIN .009 – .013 (0.229 – 0.330) NOTE: 1. DIMENSIONS IN NOTE 3 .016 – .050 (0.406 – 1.270) 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) 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 q FAX: (408) 434-0507 q U U Single + 5V Voltage-to-Frequency Converter VREF (5V) 18 + – 1/2 + LTC1040 – 10 9 100k 1/4 74C00 fOUT 1/4 74C00 4 1 + + 14 10k fIN 1µF VIN ± 0.1% FS VREF LTC1040 • TA11 12 fOUT (AVERAGE) = fIN + 10µF SW Package 18-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .447 – .463 (11.354 – 11.760) NOTE 4 18 17 16 15 14 13 12 11 10 N .325 ±.005 NOTE 3 .394 – .419 (10.007 – 10.643) 3 N/2 N/2 .050 (1.270) BSC .004 – .012 (0.102 – 0.305) .014 – .019 (0.356 – 0.482) TYP S18 (WIDE) 0502 1040fa LW/TP 1202 1K REV A • PRINTED IN USA www.linear.com © LINEAR TECHNOLOGY CORPORATION 1991