Product Folder Sample & Buy Technical Documents Support & Community Tools & Software LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 LM13700 Dual Operational Transconductance Amplifiers With Linearizing Diodes and Buffers 1 Features 3 Description * * * * * * The LM13700 series consists of two currentcontrolled transconductance amplifiers, each with differential inputs and a push-pull output. The two amplifiers share common supplies but otherwise operate independently. Linearizing diodes are provided at the inputs to reduce distortion and allow higher input levels. The result is a 10-dB signal-tonoise improvement referenced to 0.5 percent THD. High impedance buffers are provided which are especially designed to complement the dynamic range of the amplifiers. The output buffers of the LM13700 differ from those of the LM13600 in that their input bias currents (and thus their output DC levels) are independent of IABC. This may result in performance superior to that of the LM13600 in audio applications. 1 gm Adjustable Over 6 Decades Excellent gm Linearity Excellent Matching Between Amplifiers Linearizing Diodes for reduced output distortion High Impedance Buffers High Output Signal-to-Noise Ratio 2 Applications * * * * * * * * Current-Controlled Amplifiers Stereo Audio Amplifiers Current-Controlled Impedances Current-Controlled Filters Current-Controlled Oscillators Multiplexers Timers Sample-and-Hold Circuits Device Information(1) PART NUMBER LM13700 PACKAGE BODY SIZE (NOM) SOIC (16) 3.91 mm x 9.90 mm PDIP (16) 6.35 mm x 19.304 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Connection Diagram 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com Table of Contents 1 2 3 4 5 6 7 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 4 6.1 6.2 6.3 6.4 6.5 4 4 4 5 6 Absolute Maximum Ratings ..................................... Recommended Operating Conditions....................... Thermal Information .................................................. Electrical Characteristics .......................................... Typical Characteristics .............................................. Detailed Description .............................................. 9 7.1 Overview ................................................................... 9 7.2 Functional Block Diagram ......................................... 9 7.3 Feature Description................................................... 9 7.4 Device Functional Modes........................................ 10 8 Application and Implementation ........................ 11 8.1 Application Information............................................ 11 8.2 Typical Application ................................................. 11 8.3 System Examples ................................................... 12 9 Power Supply Recommendations...................... 29 10 Layout................................................................... 29 10.1 Layout Guidelines ................................................. 29 10.2 Layout Example .................................................... 29 11 Device and Documentation Support ................. 30 11.1 11.2 11.3 11.4 Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 30 30 30 30 12 Mechanical, Packaging, and Orderable Information ........................................................... 30 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision E (March 2013) to Revision F Page * Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. ................................................................................................ 1 * Removed soldering information in Absolute Maximum Ratings table .................................................................................... 4 Changes from Revision D (March 2013) to Revision E * 2 Page Changed layout of National Data Sheet to TI format ........................................................................................................... 27 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 5 Pin Configuration and Functions D or NFG Package 16-Pin SOIC or PDIP Top View Pin Functions PIN I/O DESCRIPTION NAME NO. Amp bias input 1, 16 A Current bias input Buffer input 7, 10 A Buffer amplifier input Buffer output 8, 9 A Buffer amplifier output Diode bias 2, 15 A Linearizing diode bias input Input+ 3, 14 A Positive input Input- 4, 13 A Negative input Output 5, 12 A Unbuffered output V+ 11 P Positive power supply V- 6 P Negative power supply Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 3 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com 6 Specifications 6.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted) (1) MIN Supply voltage DC input voltage MAX UNIT 36 VDC or 18 V -VS V +VS Differential input voltage 5 V Diode bias current (ID) 2 mA Amplifier bias current (IABC) 2 mA Buffer output current (2) 20 mA Power dissipation (3) TA = 25C - LM13700N 570 mW 150 C Output short circuit duration Continuous -65 Storage temperature, Tstg (1) (2) (3) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Buffer output current should be limited so as to not exceed package dissipation. For operation at ambient temperatures above 25C, the device must be derated based on a 150C maximum junction temperature and a thermal resistance, junction to ambient, as follows: LM13700N, 90C/W; LM13700M, 110C/W. 6.2 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) V+ (single-supply configuration) MIN MAX 9.5 32 UNIT V V V+ (dual-supply configuration) 4.75 16 V- (dual-supply configuration) -16 -4.75 V 0 70 C Operating temperature, TA LM13700N 6.3 Thermal Information LM13700 THERMAL METRIC (1) D (SOIC) NFG (PDIP) UNIT 16 PINS 16 PINS RJA Junction-to-ambient thermal resistance 83.0 43.8 C/W RJC(top) Junction-to-case (top) thermal resistance 44.0 34.9 C/W RJB Junction-to-board thermal resistance 40.5 28.3 C/W JT Junction-to-top characterization parameter 11.5 19.1 C/W JB Junction-to-board characterization parameter 40.2 28.2 C/W (1) 4 For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953. Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 6.4 Electrical Characteristics These specifications apply for VS = 15 V, TA = 25C, amplifier bias current (IABC) = 500 A, pins 2 and 15 open unless otherwise specified. The inputs to the buffers are grounded and outputs are open. PARAMETER TYP MAX Over specified temperature range 0.4 4 IABC = 5 A 0.3 4 VOS including diodes Diode bias current (ID) = 500 A 0.5 5 mV Input offset change 5 A IABC 500 A 0.1 3 mV 0.1 0.6 A 0.4 5 1 8 9600 13000 Input offset voltage (VOS) TEST CONDITIONS MIN Input offset current Input bias current Forward transconductance (gm) Over specified temperature range 6700 Over specified temperature range 5400 gm tracking 0.3 RL = 0, IABC = 5 A Peak output current Supply current 350 RL = 0, Over Specified Temp Range 300 IABC = 500 A, both channels Common-mode range mV A S dB 5 RL = 0, IABC = 500 A CMRR UNIT 500 650 A 2.6 mA 80 110 dB 12 13.5 V Crosstalk Referred to input (1) 20 Hz < f < 20 kHz 100 dB Differential input current IABC = 0, input = 4 V 0.02 100 Leakage current IABC = 0 (refer to test circuit) 0.2 100 Input resistance 10 Open-loop bandwidth Slew rate Unity gain compensated Buffer input current See (1) Peak buffer output voltage See (1) nA nA 26 k 2 MHz 50 0.5 V/s 2 10 A V PEAK OUTPUT VOLTAGE Positive RL = , 5 A IABC 500 A 12 14.2 V Negative RL = , 5 A IABC 500 A -12 -14.4 V VOS SENSITIVITY (1) Positive VOS/V+ 20 150 V/V Negative VOS/V- 20 150 V/V These specifications apply for VS = 15 V, IABC = 500 A, ROUT = 5-k connected from the buffer output to -VS and the input of the buffer is connected to the transconductance amplifier output. Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 5 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com 6.5 Typical Characteristics 6 Figure 1. Input Offset Voltage Figure 2. Input Offset Current Figure 3. Input Bias Current Figure 4. Peak Output Current Figure 5. Peak Output Voltage and Common Mode Range Figure 6. Leakage Current Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 Typical Characteristics (continued) Figure 7. Input Leakage Figure 8. Transconductance Figure 9. Input Resistance Figure 10. Amplifier Bias Voltage vs. Amplifier Bias Current Figure 11. Input and Output Capacitance Figure 12. Output Resistance Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 7 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com Typical Characteristics (continued) Figure 13. Distortion vs. Differential Input Voltage Figure 14. Voltage vs. Amplifier Bias Current Figure 15. Output Noise vs Frequency 8 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 7 Detailed Description 7.1 Overview The LM13700 is a two channel current controlled differential input transconductance amplifier with additional output buffers. The inputs include linearizing diodes to reduce distortion, and the output current is controlled by a dedicated pin. The outputs can sustain a continuous short to ground. 7.2 Functional Block Diagram Figure 16. One Operational Transconductance Amplifier 7.3 Feature Description 7.3.1 Circuit Description The differential transistor pair Q4 and Q5 form a transconductance stage in that the ratio of their collector currents is defined by the differential input voltage according to the transfer function: (1) where VIN is the differential input voltage, kT/q is approximately 26 mV at 25C and I5 and I4 are the collector currents of transistors Q5 and Q4 respectively. With the exception of Q12 and Q13, all transistors and diodes are identical in size. Transistors Q1 and Q2 with Diode D1 form a current mirror which forces the sum of currents I4 and I5 to equal IABC: I4 + I5 = IABC (2) where IABC is the amplifier bias current applied to the gain pin. For small differential input voltages the ratio of I4 and I5 approaches unity and the Taylor series of the In function is approximated as: (3) (4) Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 9 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com Feature Description (continued) Collector currents I4 and I5 are not very useful by themselves and it is necessary to subtract one current from the other. The remaining transistors and diodes form three current mirrors that produce an output current equal to I5 minus I4 thus: (5) The term in brackets is then the transconductance of the amplifier and is proportional to IABC. 7.3.2 Linearizing Diodes For differential voltages greater than a few millivolts, Equation 3 becomes less valid and the transconductance becomes increasingly nonlinear. Figure 19 demonstrates how the internal diodes can linearize the transfer function of the amplifier. For convenience assume the diodes are biased with current sources and the input signal is in the form of current IS. Since the sum of I4 and I5 is IABC and the difference is IOUT, currents I4 and I5 is written as follows: (6) Since the diodes and the input transistors have identical geometries and are subject to similar voltages and temperatures, the following is true: (7) Notice that in deriving Equation 7 no approximations have been made and there are no temperature-dependent terms. The limitations are that the signal current not exceed ID / 2 and that the diodes be biased with currents. In practice, replacing the current sources with resistors will generate insignificant errors. 7.4 Device Functional Modes Use in single ended or dual supply systems requires minimal changes. The outputs can support a sustained short to ground. Note that use of the LM13700 in 5 V supply systems requires will reduce signal dynamic range; this is due to the PNP transistors having a higher VBE than the NPN transistors. 7.4.1 Output Buffers Each channel includes a separate output buffer which consists of a Darlington pair transistor that can drive up to 20mA. 10 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 8 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI's customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 8.1 Application Information An OTA is a versatile building block analog component that can be considered an ideal transistor. The LM13700 can be used in a wide variety of applications, from voltage-controlled amplifiers and filters to VCOs. The 2 wellmatched, independent channels make the LDC13700 well suited for stereo audio applications. 8.2 Typical Application Figure 17. Voltage Controlled Amplifier 8.2.1 Design Requirements For this example application, the system requirements provide a volume control for a 1 VP input signal with a THD < 0.1% using 15 V supplies. The volume control varies between -13 V and 15 V and needs to provide an adjustable gain range of >30dB. 8.2.2 Detailed Design Procedure Using the linearizing diodes is recommended for most applications, as they greatly reduce the output distortion. It is required that the diode bias current, ID be greater than twice the input current, IS. As the input voltage has a DC level of 0 V, the Diode Bias input pins are 1 diode drop above 0 V, which is +0.7 V. Tying the bias to the clean V+ supply, results in a voltage drop of 14.3 V across RD. Using the recommended 1mA for ID is appropriate here, and with VS=+15 V, the voltage drop is 14.3 V, and so using the standard value of 13-k is acceptable and will provide the desired gain control. To obtain the <0.1% THD requirement, the differential input voltage must be <60mVpp when the linearizing diodes are used. The input divider on the input will reduce the 1 VP input to 33mVPP, which is within the desired spec. Next, set IBIAS. The Bias Input pins (pins 1 or 16), are 2 diode drops above the negative supply, and therefore VBIAS = 2(VBE) + V- , which for this application is -13.6 V. To set IBIAS to 1ma when VC = 15 V requires a 28.6-k; 30-k is a standard value and is used for this application. The gain will be linear with the applied voltage. Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 11 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com Typical Application (continued) 8.2.3 Application Curve 0 Signal Amplitude (dB) -5 -10 -15 -20 -25 -30 -35 -15 -10 -5 0 5 Control Voltage (V) 10 15 D001 Figure 18. Signal Amplitude vs Control Voltage 8.3 System Examples 8.3.1 Voltage-Controlled Amplifiers Figure 20 shows how the linearizing diodes is used in a voltage-controlled amplifier. To understand the input biasing, it is best to consider the 13-k resistor as a current source and use a Thevenin equivalent circuit as shown in Figure 21. This circuit is similar to Figure 19 and operates the same. The potentiometer in Figure 20 is adjusted to minimize the effects of the control signal at the output. Figure 19. Linearizing Diodes For optimum signal-to-noise performance, IABC should be as large as possible as shown by the Output Voltage vs Amplifier Bias Current graph. Larger amplitudes of input signal also improve the S/N ratio. The linearizing diodes help here by allowing larger input signals for the same output distortion as shown by the Distortion vs. Differential Input Voltage graph. S/N may be optimized by adjusting the magnitude of the input signal via RIN (Figure 20) until the output distortion is below the desired level. The output voltage swing can then be set at any level by selecting RL. Although the noise contribution of the linearizing diodes is negligible relative to the contribution of the amplifier's internal transistors, ID should be as large as possible. This minimizes the dynamic junction resistance of the diodes (re) and maximizes their linearizing action when balanced against RIN. A value of 1 mA is recommended for ID unless the specific application demands otherwise. 12 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 System Examples (continued) Figure 20. Voltage-Controlled Amplifier Figure 21. Equivalent VCA Input Circuit 8.3.2 Stereo Volume Control The circuit of Figure 22 uses the excellent matching of the two LM13700 amplifiers to provide a Stereo Volume Control with a typical channel-to-channel gain tracking of 0.3 dB. RP is provided to minimize the output offset voltage and may be replaced with two 510 resistors in AC-coupled applications. For the component values given, amplifier gain is derived for Figure 20 as being: (8) If VC is derived from a second signal source then the circuit becomes an amplitude modulator or two-quadrant multiplier as shown in Figure 23, where: (9) The constant term in the above equation may be cancelled by feeding IS x IDRC/2(V- + 1.4 V) into IO. The circuit of Figure 24 adds RM to provide this current, resulting in a four-quadrant multiplier where RC is trimmed such that VO = 0 V for VIN2 = 0 V. RM also serves as the load resistor for IO. Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 13 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com System Examples (continued) Figure 22. Stereo Volume Control Figure 23. Amplitude Modulator Figure 24. Four-Quadrant Multiplier 14 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 System Examples (continued) Noting that the gain of the LM13700 amplifier of Figure 21 may be controlled by varying the linearizing diode current ID as well as by varying IABC, Figure 25 shows an AGC Amplifier using this approach. As VO reaches a high enough amplitude (3 VBE) to turn on the Darlington transistors and the linearizing diodes, the increase in ID reduces the amplifier gain so as to hold VO at that level. 8.3.3 Voltage-Controlled Resistors An Operational Transconductance Amplifier (OTA) may be used to implement a Voltage Controlled Resistor as shown in Figure 26. A signal voltage applied at RX generates a VIN to the LM13700 which is then multiplied by the gm of the amplifier to produce an output current, thus: (10) where gm 19.2IABC at 25C. Note that the attenuation of VO by R and RA is necessary to maintain VIN within the linear range of the LM13700 input. Figure 27 shows a similar VCR where the linearizing diodes are added, essentially improving the noise performance of the resistor. A floating VCR is shown in Figure 28, where each "end" of the "resistor" may be at any voltage within the output voltage range of the LM13700. Figure 25. AGC Amplifier Figure 26. Voltage-Controlled Resistor, Single-Ended Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 15 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com System Examples (continued) Figure 27. Voltage-Controlled Resistor with Linearizing Diodes 8.3.4 Voltage-Controlled Filters OTA's are extremely useful for implementing voltage controlled filters, with the LM13700 having the advantage that the required buffers are included on the I.C. The VC Lo-Pass Filter of Figure 29 performs as a unity-gain buffer amplifier at frequencies below cut-off, with the cut-off frequency being the point at which XC/gm equals the closed-loop gain of (R/RA). At frequencies above cut-off the circuit provides a single RC roll-off (6 dB per octave) of the input signal amplitude with a -3 dB point defined by the given equation, where gm is again 19.2 x IABC at room temperature. Figure 30 shows a VC High-Pass Filter which operates in much the same manner, providing a single RC roll-off below the defined cut-off frequency. Additional amplifiers may be used to implement higher order filters as demonstrated by the two-pole Butterworth Lo-Pass Filter of Figure 31 and the state variable filter of Figure 32. Due to the excellent gm tracking of the two amplifiers, these filters perform well over several decades of frequency. Figure 28. Floating Voltage-Controlled Resistor 16 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 System Examples (continued) Figure 29. Voltage-Controlled Low-Pass Filter Figure 30. Voltage-Controlled Hi-Pass Filter Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 17 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com System Examples (continued) Figure 31. Voltage-Controlled 2-Pole Butterworth Lo-Pass Filter Figure 32. Voltage-Controlled State Variable Filter 8.3.5 Voltage-Controlled Oscillators The classic Triangular/Square Wave VCO of Figure 33 is one of a variety of Voltage Controlled Oscillators which may be built utilizing the LM13700. With the component values shown, this oscillator provides signals from 200 kHz to below 2 Hz as IC is varied from 1 mA to 10 nA. The output amplitudes are set by IA x RA. Note that the peak differential input voltage must be less than 5 V to prevent zenering the inputs. A few modifications to this circuit produce the ramp/pulse VCO of Figure 34. When VO2 is high, IF is added to IC to increase amplifier A1's bias current and thus to increase the charging rate of capacitor C. When VO2 is low, IF goes to zero and the capacitor discharge current is set by IC. 18 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 System Examples (continued) The VC Lo-Pass Filter of Figure 29 may be used to produce a high-quality sinusoidal VCO. The circuit of Figure 34 employs two LM13700 packages, with three of the amplifiers configured as lo-pass filters and the fourth as a limiter/inverter. The circuit oscillates at the frequency at which the loop phase-shift is 360 or 180 for the inverter and 60 per filter stage. This VCO operates from 5 Hz to 50 kHz with less than 1% THD. Figure 33. Triangular/Square-Wave VCO Figure 34. Ramp/Pulse VCO Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 19 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com System Examples (continued) Figure 35. Sinusoidal VCO Figure 36 shows how to build a VCO using one amplifier when the other amplifier is needed for another function. Figure 36. Single Amplifier VCO 8.3.6 Additional Applications Figure 37 presents an interesting one-shot which draws no power supply current until it is triggered. A positivegoing trigger pulse of at least 2 V amplitude turns on the amplifier through RB and pulls the non-inverting input high. The amplifier regenerates and latches its output high until capacitor C charges to the voltage level on the non-inverting input. The output then switches low, turning off the amplifier and discharging the capacitor. The capacitor discharge rate is speeded up by shorting the diode bias pin to the inverting input so that an additional discharge current flows through DI when the amplifier output switches low. A special feature of this timer is that the other amplifier, when biased from VO, can perform another function and draw zero stand-by power as well. 20 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 System Examples (continued) Figure 37. Zero Stand-By Power Timer The operation of the multiplexer of Figure 38 is very straightforward. When A1 is turned on it holds VO equal to VIN1 and when A2 is supplied with bias current then it controls VO. CC and RC serve to stabilize the unity-gain configuration of amplifiers A1 and A2. The maximum clock rate is limited to about 200 kHz by the LM13700 slew rate into 150 pF when the (VIN1-VIN2) differential is at its maximum allowable value of 5 V. The Phase-Locked Loop of Figure 39 uses the four-quadrant multiplier of Figure 24 and the VCO of Figure 36 to produce a PLL with a 5% hold-in range and an input sensitivity of about 300 mV. Figure 38. Multiplexer Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 21 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com System Examples (continued) Figure 39. Phase Lock Loop The Schmitt Trigger of Figure 40 uses the amplifier output current into R to set the hysteresis of the comparator; thus VH = 2 x R x IB. Varying IB will produce a Schmitt Trigger with variable hysteresis. Figure 40. Schmitt Trigger Figure 41 shows a Tachometer or Frequency-to-Voltage converter. Whenever A1 is toggled by a positive-going input, an amount of charge equal to (VH-VL) Ct is sourced into Cf and Rt. This once per cycle charge is then balanced by the current of VO/Rt. The maximum FIN is limited by the amount of time required to charge Ct from VL to VH with a current of IB, where VL and VH represent the maximum low and maximum high output voltage swing of the LM13700. D1 is added to provide a discharge path for Ct when A1 switches low. The Peak Detector of Figure 42 uses A2 to turn on A1 whenever VIN becomes more positive than VO. A1 then charges storage capacitor C to hold VO equal to VIN PK. Pulling the output of A2 low through D1 serves to turn off A1 so that VO remains constant. 22 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 System Examples (continued) Figure 41. Tachometer Figure 42. Peak Detector and Hold Circuit The Ramp-and-Hold of Figure 44 sources IB into capacitor C whenever the input to A1 is brought high, giving a ramp-rate of about 1 V/ms for the component values shown. The true-RMS converter of Figure 45 is essentially an automatic gain control amplifier which adjusts its gain such that the AC power at the output of amplifier A1 is constant. The output power of amplifier A1 is monitored by squaring amplifier A2 and the average compared to a reference voltage with amplifier A3. The output of A3 provides bias current to the diodes of A1 to attenuate the input signal. Because the output power of A1 is held constant, the RMS value is constant and the attenuation is directly proportional to the RMS value of the input voltage. The attenuation is also proportional to the diode bias current. Amplifier A4 adjusts the ratio of currents through the diodes to be equal and therefore the voltage at the output of A4 is proportional to the RMS value of the input voltage. The calibration potentiometer is set such that VO reads directly in RMS volts. Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 23 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com System Examples (continued) Figure 43. Sample-Hold Circuit Figure 44. Ramp and Hold 24 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 System Examples (continued) Figure 45. True RMS Converter The circuit of Figure 46 is a voltage reference of variable Temperature Coefficient. The 100-k potentiometer adjusts the output voltage which has a positive TC above 1.2 V, zero TC at about 1.2 V, and negative TC below 1.2 V. This is accomplished by balancing the TC of the A2 transfer function against the complementary TC of D1. The wide dynamic range of the LM13700 allows easy control of the output pulse width in the Pulse Width Modulator of Figure 47. For generating IABC over a range of 4 to 6 decades of current, the system of Figure 48 provides a logarithmic current out for a linear voltage in. Since the closed-loop configuration ensures that the input to A2 is held equal to 0 V, the output current of A1 is equal to I3 = -VC/RC. The differential voltage between Q1 and Q2 is attenuated by the R1,R2 network so that A1 may be assumed to be operating within its linear range. From Equation 5, the input voltage to A1 is: (11) The voltage on the base of Q1 is then (12) The ratio of the Q1 and Q2 collector currents is defined by: (13) Combining and solving for IABC yields: (14) This logarithmic current is used to bias the circuit of Figure 22 to provide temperature independent stereo attenuation characteristic. Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 25 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com System Examples (continued) Figure 46. Delta VBE Reference Figure 47. Pulse Width Modulator 26 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 System Examples (continued) Figure 48. Logarithmic Current Source Figure 49. Unity Gain Follower Figure 50. Leakage Current Test Circuit Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 27 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com System Examples (continued) Figure 51. Differential Input Current Test Circuit 28 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 LM13700 www.ti.com SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 9 Power Supply Recommendations The LM13700 can operate with either a single-ended supply or a dual supplies. The supplies should be low impedance sources with sufficient bypassing. Use of low-ESR sufficiently rated voltage ceramic capacitors is recommended. When bypassing dual supply configurations, the supply bypass capacitors should couple to ground. 10 Layout 10.1 Layout Guidelines Place supply bypass capacitors as close to the appropriate supply pins as possible. When multiple bypass capacitors are used, the smallest value capacitor should be closest to the supply pin. Use of a ground plane to minimize ground impedance and provide constant signal impedance is recommended. Avoid routing signal traces over any gaps in the ground plane. Feedback components and passives should be placed close to the device pins to minimize parasitic impedances. When using capacitors to limit bandwidth, the capacitor should be closer to the device pin than any ballasting or gain resistors. 2 V+ 1 IBIAS1 1 IBIAS1 1 VIN1 2 VOUT1 1 VOUT1 1 VIN2 3 VIN1+ 1 14 VIN2+ VIN2 VIN2+ 2 GND 2 DARL1 v- 1 GND 2 V- GND V- v+ 6 V- 7 DARL1 V- 11 V+ v+ 10 DARL2 v+ 2 V+ V+ 1 GND 1 GND 1 VIN2- 1 VOUT2 GND 2 GND 1 GND 2 VOUT2 VOUT2 GND 9 VOUT2 8 VOUT1 v+ VOUT1 2 12 DARL2 DARL2DARL2 5 DARL1 GND 1 VIN2- 13 VIN2- 4VIN1- 1 GND 2 V+ 2 VIN2+ DARL2 2 VIN1- 1 IBIAS2 16 IBIAS2 15 ILIN2 GND 1 GND 1 V+ v+ VOUT1 1 VIN1+ 1 VIN1- GND 2 GND 2 GND 2 ILIN2 2 ILIN1 DARL1 GND GND 2 VIN1+ ILIN2 2 IBIAS1 v+ 1 V+ ILIN1 10.2 Layout Example Figure 52. Layout Recommendation Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 29 LM13700 SNOSBW2F - NOVEMBER 1999 - REVISED NOVEMBER 2015 www.ti.com 11 Device and Documentation Support 11.1 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TI E2ETM Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 11.2 Trademarks E2E is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 11.3 Electrostatic Discharge Caution These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. 11.4 Glossary SLYZ022 -- TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 12 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. 30 Submit Documentation Feedback Copyright (c) 1999-2015, Texas Instruments Incorporated Product Folder Links: LM13700 PACKAGE OPTION ADDENDUM www.ti.com 11-Jan-2021 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (C) Device Marking (3) (4/5) (6) LM13700M/NOPB ACTIVE SOIC D 16 48 RoHS & Green SN Level-1-260C-UNLIM 0 to 70 LM13700M LM13700MX/NOPB ACTIVE SOIC D 16 2500 RoHS & Green SN Level-1-260C-UNLIM 0 to 70 LM13700M LM13700N/NOPB ACTIVE PDIP NFG 16 25 RoHS & Green SN Level-1-NA-UNLIM 0 to 70 LM13700N (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 11-Jan-2021 In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 15-Sep-2018 TAPE AND REEL INFORMATION *All dimensions are nominal Device LM13700MX/NOPB Package Package Pins Type Drawing SOIC D 16 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2500 330.0 16.4 Pack Materials-Page 1 6.5 B0 (mm) K0 (mm) P1 (mm) 10.3 2.3 8.0 W Pin1 (mm) Quadrant 16.0 Q1 PACKAGE MATERIALS INFORMATION www.ti.com 15-Sep-2018 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM13700MX/NOPB SOIC D 16 2500 367.0 367.0 35.0 Pack Materials-Page 2 MECHANICAL DATA NFG0016E N0016E N16E (Rev G) www.ti.com IMPORTANT NOTICE AND DISCLAIMER TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES "AS IS" AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. 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