Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Op-amp Transconductance SOIC 16 N

LM13700

www.ti.com

SNOSBW2E –NOVEMBER 1999–REVISED MARCH 2013

LM13700 Dual Operational Transconductance Amplifiers with Linearizing Diodes and

Buffers

Check for Samples: LM13700

FEATURES

DESCRIPTION

The LM13700 series consists of two current

• g

Adjustable over 6 Decades

controlled transconductance amplifiers, each with

• Excellent g

Linearity

differential inputs and a push-pull output. The two

• Excellent Matching between Amplifiers

amplifiers share common supplies but otherwise

operate independently. Linearizing diodes are

• Linearizing Diodes

provided at the inputs to reduce distortion and allow

• High Impedance Buffers

higher input levels. The result is a 10 dB signal-to-

• High Output Signal-to-Noise Ratio

noise improvement referenced to 0.5 percent THD.

High impedance buffers are provided which are

APPLICATIONS

especially designed to complement the dynamic

range of the amplifiers. The output buffers of the

• Current-Controlled Amplifiers

LM13700 differ from those of the LM13600 in that

• Current-Controlled Impedances

their input bias currents (and hence their output DC

levels) are independent of I

ABC

. This may result in

• Current-Controlled Filters

performance superior to that of the LM13600 in audio

• Current-Controlled Oscillators

applications.

• Multiplexers

• Timers

• Sample-and-Hold circuits

Connection Diagram

Figure 1. PDIP and SOIC Packages-Top View

See Package Number D0016A or NFG0016E

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (32 pages)

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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 LM13700 Dual Operational Transconductance Amplifiers with Linearizing Diodes and Buffers Check for Samples: LM13700 FEATURES DESCRIPTION • • • • • • The LM13700 series consists of two current controlled transconductance amplifiers, each with differential inputs and a push-pull output. The two amplifiers share common supplies but otherwise operate independently.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com 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.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 Electrical Characteristics (1) Parameter Test Conditions LM13700 Units Typ Max Over Specified Temperature Range 0.4 4 IABC = 5 μA 0.3 4 VOS Including Diodes Diode Bias Current (ID) = 500 μA 0.5 5 mV Input Offset Change 5 μA ≤ IABC ≤ 500 μA 0.1 3 mV 0.1 0.6 μA 0.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com Schematic Diagram Figure 2. One Operational Transconductance Amplifier Typical Application Figure 3.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 Typical Performance Characteristics Input Offset Voltage Input Offset Current Figure 4. Figure 5. Input Bias Current Peak Output Current Figure 6. Figure 7. Peak Output Voltage and Common Mode Range Leakage Current Figure 8. Figure 9.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) 6 Input Leakage Transconductance Figure 10. Figure 11. Input Resistance Amplifier Bias Voltage vs. Amplifier Bias Current Figure 12. Figure 13. Input and Output Capacitance Output Resistance Figure 14. Figure 15.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Distortion vs. Differential Input Voltage Voltage vs. Amplifier Bias Current Figure 16. Figure 17. Output Noise vs. Frequency Figure 18. Figure 19.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) Figure 20. Leakage Current Test Circuit Figure 21.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 (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.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com APPLICATIONS Voltage Controlled Amplifiers Figure 23 shows how the linearizing diodes can be used in a voltage-controlled amplifier. To understand the input biasing, it is best to consider the 13 kΩ resistor as a current source and use a Thevenin equivalent circuit as shown in Figure 24. This circuit is similar to Figure 22 and operates the same.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 Figure 24. Equivalent VCA Input Circuit Stereo Volume Control The circuit of Figure 25 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 510Ω resistors in AC-coupled applications.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com Figure 26. Amplitude Modulator Figure 27. Four-Quadrant Multiplier Noting that the gain of the LM13700 amplifier of Figure 24 may be controlled by varying the linearizing diode current ID as well as by varying IABC, Figure 28 shows an AGC Amplifier using this approach.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 Figure 28. AGC Amplifier Figure 29. Voltage Controlled Resistor, Single-Ended Figure 30.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com 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 32 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).
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 Figure 33. Voltage Controlled Hi-Pass Filter Figure 34.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com Figure 35. Voltage Controlled State Variable Filter Voltage Controlled Oscillators The classic Triangular/Square Wave VCO of Figure 36 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 × RA.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 Figure 37. Ramp/Pulse VCO Figure 38. Sinusoidal VCO Figure 39 shows how to build a VCO using one amplifier when the other amplifier is needed for another function.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com Figure 39. Single Amplifier VCO Additional Applications Figure 40 presents an interesting one-shot which draws no power supply current until it is triggered. A positivegoing trigger pulse of at least 2V 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.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 Figure 41. Multiplexer Figure 42. Phase Lock Loop The Schmitt Trigger of Figure 43 uses the amplifier output current into R to set the hysteresis of the comparator; thus VH = 2 × R × IB. Varying IB will produce a Schmitt Trigger with variable hysteresis.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com Figure 43. Schmitt Trigger Figure 44 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.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 The Ramp-and-Hold of Figure 47 sources IB into capacitor C whenever the input to A1 is brought high, giving a ramp-rate of about 1V/ms for the component values shown. The true-RMS converter of Figure 48 is essentially an automatic gain control amplifier which adjusts its gain such that the AC power at the output of amplifier A1 is constant.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com Figure 48. True RMS Converter The circuit of Figure 49 is a voltage reference of variable Temperature Coefficient. The 100 kΩ potentiometer adjusts the output voltage which has a positive TC above 1.2V, zero TC at about 1.2V, and negative TC below 1.2V. This is accomplished by balancing the TC of the A2 transfer function against the complementary TC of D1.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 Figure 49. Delta VBE Reference Figure 50.
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LM13700 SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 www.ti.com Figure 51.
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LM13700 www.ti.com SNOSBW2E – NOVEMBER 1999 – REVISED MARCH 2013 REVISION HISTORY Changes from Revision D (March 2013) to Revision E • Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 1-Nov-2013 (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish 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.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant LM13700MX SOIC D 16 2500 330.0 16.4 6.5 10.3 2.3 8.0 16.0 Q1 LM13700MX/NOPB SOIC D 16 2500 330.0 16.4 6.5 10.3 2.3 8.0 16.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM13700MX SOIC D 16 2500 367.0 367.0 35.0 LM13700MX/NOPB SOIC D 16 2500 367.0 367.0 35.
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MECHANICAL DATA NFG0016E N0016E N16E (Rev G) www.ti.
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