Differential mic input

Differential mic input. Find parameters, ordering and quality information. An auxil-iary ADC path can be used to track any DC voltage. Line-in can handle strong (think loud) currents, whereas a mic-in can handle very low current levels. The device supports both Microphone and Line In input on the ADC Channel. Microphone and line-level inputs are connected to the CS4207 using standard 1/8” (3. Resistor Value Selection. The differential microphone input circuit and the placement rules are listed below: The DC blocking capacitors (C21 and C34) are placed as close as possible to IS2083BM. 5 dB (96 kHz sample rate) Dynamic Range: 116 dB (A) THD+N Oct 17, 2014 · A fixed-point arithmetic implementation of the modified algorithm for wideband handsfree communication (fs =16kHz) using two miniature digital MEMS microphone capsules is described using a fast time-domain notch adaptation algorithm to reliably track interfering sound sources. The 60Hz EMF and its harmonics affecting Nov 15, 2012 · When bands are on stage in front of a massive backline of amps, the sound pressure level at the singers' microphones can be very high. The line-driver takes the single-ended output of the basic ECM circuit of Figure 2 and converts it into a fully balanced output. It's a pretty simple abbreviation for X Connector, L ocking Connector, R ubber Boot. This method relies on. These use, simplified, a buffer and an inverter. Single-ended inputs. The microphone input circuit consists of two differential input/differential output amplifiers (MIC Amp 1 and MIC Amp 2). 4-kHz Passband The device supports line and microphone inputs, and allows for both single-ended and differential input configurations. The MIC_BIAS filtering components (R6 and C22) are placed close to the microphone. 7uF capacitors and input voltage attenuator resistors but always got noise in the output sound in the other bluetooth audio receiver. With audio signals, sound is transferred as a voltage into our mixers, audio interfaces, amplifiers, and speakers. No bass boosting. In addition, the MAX4060/MAX4062 have a low-noise microphone bias generator. Differential signalling provides better measured performance. A single-ended measurement is taken as the voltage difference between a wire and ground Jun 9, 2021 · This is where the three pins of an XLR come into play. This is the magical part. However, there are certain scenarios where microphones can also function as output devices, such as when using built-in speakers or headphones in specific microphone models. Internal Mic noise developed between the mic hot and gnd won't be cancelled. An operational amplifier or op-amp (Figure 1) is an example of a difference amplifier. –Microphone are commonly specified for 2 to 3 kohm loads. 2 volts peak to peak. The standard Differential Amplifier circuit now becomes a differential voltage comparator by “Comparing” one input voltage to the other. 048-MHz Master Clock Rate; 300-Hz to 3. If you have questions about quality, packaging or ordering TI products, see TI support. Some cards may have several LOW lines to provide extra places The differential input senses a signal by measuring the voltage difference between conductors. I already tried a direct differential audio input to MIC pins with those 4. A stereo single-ended line input, with a configurable preamplifier, can either be recorded by the ADC or routed directly to the headphone or line output amplifiers. The active components of the circuit (amplifiers A1 and A2) proven in figure 1 are within IC1. The locking connectors are relatively large and heavy, explicitly designed for carrying balanced signals and wired using balanced (microphone) cable. There is a persistent quandary out there concerning the difference between single-ended and differential analog input configurations. is there any way to convert single ended audio signal to differential one. Dec 11, 2023 · Learn about microphone inputs and outputs, including types, common uses, and troubleshooting tips. So in an impedance balanced line that has a 1V signal on one conductor and no signal on the other (0V), the input would pass a 1V signal ( the difference between the two conductors). The project shown here is a microphone preamplifier provides high quality amplification, optimized for use in computers, media and mobile applications. Usually, your differential signal is symmetric around 0 V. A microphone is a sound-to-electricity transducer which means that any output signal corresponds to a specific sound as input. First, a simple alignment procedure equalizes the power levels of the input signals. 2 V. The "rubber boot" portion of the connector isn't always part of the equation these days, however, as it's no longer necessary. The TAC5212 supports both differential and Single-ended input and output. We start with the design of first-order time-domain DMAs, then we move to higher orders. With those high level This document covers important information about analog and digital microphone electrical interfaces and signal requirements. 40 dB with excellent power-supply and common-mode rejection ratios. The equivalent input noise (EIN) is the acoustic level, expressed in dBSPL, corresponding to the residual noise as output. Figure 31 shows the sequences of the power-down and the power-up. Jan 8, 2024 · The MAX4060/MAX4062 are capable of switching their output between the differential input and a single-ended auxiliary microphone amplifier input. Apr 1, 2020 · The first one is a single transistor simple microphone circuit, very simple to hook up using an electret microphone or MIC and an audio amplifier. This device features an adjustable gain from 0 to. Single-Ended or Differential • Single-ended. Here, we present the expression Left channel positive differential MIC input C4 IN1RN/ DMICDAT1 Analogue input / Digital Input Right channel single-ended MIC input / Right channel negative differential MIC input / Digital MIC data input 1 A5 IN1RP Analogue Input Right channel line input / Right channel positive differential MIC input B3 IN2LN/ DMICCLK2 Analogue Input Input Resistance RIN Either differential input 100 kΩ Input Resistance Match RMATCH 1 % Input Noise-Voltage Density en AV = 10V/V, f = 1kHz 100 AV = 100V/V, f = 1kHz, MAX4061/MAX4062 nV/√Hz only 20 RMS Output Noise Voltage VNRMS AV = 10V/V, BW = 22Hz to 22kHz 125 µVRMS MAX4060/MAX4061/ MAX4062 Differential Microphone Preamplifiers with This topology was selected for a few reasons. (When used with the 5171 companion digital control part, the maximum input signal is +21dBu due to the 5171’s minimum gain of 5. Buffered and Inverted = Differential. Aug 3, 2023 · There are microphone preamplifiers such as the 1580 from THAT Corp with good noise and differential inputs that are built as instrumentation amplifiers, but designed to work at relatively low impedance connected to the input. For example, by connecting one input to a fixed voltage reference set up on one leg of the resistive bridge network and the other to either a “Thermistor” or a “Light Dependant Resistor” the amplifier circuit can be used to detect either low or Jun 30, 2013 · Differential input circuits are used to cancel unwanted noise signals which are picked up from outside sources on both inputs equally and in phase - like hum from 60 cycle AC. The single-ended line inputs, with configurable preamplifier, can be sent to the ADC for record or routed directly to the headphone amplifier for playback. The differential signal, and the cabling method used, eliminates common mode noise. A miniature differential microphone is described having a low-noise floor. Early directional microphones were created using an omnidirectional microphone and a gradient microphone. Jan 25, 2018 · This differential input is driven by a floating (transformer-coupled) microphone (600 Ohms). We recommend using the audio codec breakout WM8960. It also imparts information about important parameters like Acoustic Overload Point (AOP), Signal to Noise Ratio (SNR), dynamic range, sensitivity and bandwidth Feb 3, 2021 · The differential pair—sometimes called the long-tailed pair—is a widely used building block in electronic circuits, particularly in op amps. Feb 7, 2024 · Conclusion. Jul 7, 2023 · Microphones have male outputs, and mic preamps have female input connectors on the front; hence, the standard XLR cable has a female on one end and a male on the other. Copyright ©2010, THAT Corporation. It runs at 10kohm as opposed to a mic-in’s paltry 600-1Kohm. The topology pre-dates the solid-state era and is generally attributed to Alan Blumlein, when it appeared in one of his patents in 1936. In Input, select the microphone that you want to test. 03 mW in Power-Down Mode; 2. A single signals input has no commond mode range because there is only ONE low wire, which is shared by all inputs. Microphone types include single and differential Analog MEMS microphones, Digital PDM MEMS microphones, and Digital I2S MEMS microphones. the signal source being grounded (earthed), and. That is, gain from Left MICPGA positive pin (IN2_L) is 3. When using a pseudo-differential microphone configuration, make sure to include a 2. For a practical use of DMA, however, it is IN2LN D2 VDD_A I Left-channel negative differential mic/line input — Input IN2LP C3 VDD_A I Left-channel single-ended mic/line input/positive A differential (or difference) amplifier is a two-input circuit that amplifies only the difference between its two inputs. The MAX4060 has a fixed gain of 10V/V and is PC99/2001 compliant. And single-ended input worked much better, without noise. One input is labeled as +, and the other as -. But you’re highly unlikely to notice The TAC5212 is a high performance Stereo Codec with 2 VRMS differential Input, 118 dB Stereo ADC and 2 VRMS Stereo DAC. The device supports line and microphone inputs, and allows for both single-ended and differential input configurations. Oct 5, 2020 · The MAX9880A's stereo differential microphone inputs can support either analog or digital microphones. First, it allows for single-supply operation to be easily accommodated by biasing the non-inverting input of the op amp to the mid-supply point. If the bar moves while you speak, your microphone is working properly. What has to be considered ? Input being a crystal microphone, gain set to near 200. The KAS-33100-0004 Muskie microphone evaluation kit allows for simple and easy evaluation of Knowles SiSonicTM MEMS microphones. Here, we present the expression Left channel positive differential MIC input / Jack detect input pin 3 LINPUT2 Analogue Input Left channel line input / Left channel positive differential MIC input 4 LINPUT1 Analogue Input Left channel single-ended MIC input / Left channel negative differential MIC input 5 RINPUT1 Analogue Input Right channel single-ended MIC input / Pseudo-Differential Cable The vast majority of my amplifiers have differential inputs. I use this for three reasons: Differential signalling sounds better. 1–3 Due to the inherently small inter microphone spacings and directional characteristics, these arrays are attractive in practical applications. Mar 2, 2012 · The one slight problem is the mic input sensitivity. Some cards may have several LOW lines to provide extra places Right channel negative differential MIC input / Digital MIC data input 2 D2 IN2RP Analogue Input Right channel single-ended MIC input / Right channel line input / Right channel positive differential MIC input A1 IN3LN/ DMICCLK3 Analogue Input / Digital Output Left channel negative differential MIC input / Digital MIC clock output 3 A2 IN3LP Sep 26, 2014 · We revisit the standard differential microphone of [1] and propose three algorithmic enhancements. The single-ended line inputs, with configurable preamplifier, can be sent to the Sep 12, 2011 · Single-ended vs. If don't see the bar moving, go to Test your microphone and select Start test. Two Differential Microphone Inputs Differential Earphone Outputs and One Single-Ended Earphone Output Earphone and Microphone Mute Programmable Transmit, Receive, and Sidetone Paths With Extended Gain and Attenuation Ranges Programmable for 15-Bit Linear Data or 8-Bit Companded (µ-law and A-law) Mode Supports PCM Clock Rates of 128 kHz and 2. An op-amp (or operational amplifier) is a small IC that has two inputs and a single output. this output level is already in the territory of Feb 15, 2011 · Both these types of amplifier are powered in the same way, but the differential amplifier, amplifies the difference between its two inputs, whereas the single ended amplifier, amplifies the difference between its single input and ground. Switching from the motile planktonic bacterial lifestyle to a biofilm existence is stimulated by the signalling molecule bis-(3′-5′)-cyclic-diguanosine monophosphate (cyclic-di-GMP), which is antagonistically controlled by diguanylate cyclases (DGCs; characterized by GGDEF domains) and specific phosphodiesterases (PDEs; mostly featuring EAL domains). These features make this microphone ideal for full-bandwidth, wide dynamic range audio capture applications, such as in a recording studio or on stage. Nov 29, 2021 · Theoretically, the differential drive delivers an increase in audio performance due to the doubling of the amp’s voltage slew rate (how quickly the amp responds to input signals), lower noise, and reduced crosstalk due to the elimination of the shared audio ground between the left and right channels. 2 times higher than the gain of Left MICPGA negative input (IN2_R), thus CMRR performance is Jan 6, 2021 · So I need to attenuate 5V to 500mV-1V input and convert it to single-ended. Specifically, many have the impression that analog inputs configured to be single-ended cannot measure negative-going voltages inputs. These devices offer an integrated high-voltage, programmable microphone bias, and input diagnostic circuitry that allow direct connection to microphone-based automotive systems with full fault INMP411 consists of a MEMS microphone element and an impedance-matching amplifier. Before the audio signal passes to the preamp stage of the amplifier, it goes through an op-amp. The microphone and signal paths of microphone must be routed on same layer. Acoust. A1 runs as a non-inverting amplifier along with the microphone input is given to pin 1 through coupling capacitor C1. Evaluate two input channels of audio from multiple MEMS microphone types. To sum up, Microphones are primarily input devices that convert sound into electrical signals for recording or transmitting purposes. Jun 9, 2017 · In a device with a differential input design, the shield of the RCA cable is completely isolated from the chassis. The microphone input is cited as taking only 740 mVrms while distortion stays below 5% (at the minimum gain, 0dB). We also evaluate the performance of the various orders and patterns by means of the beampattern, WNG, DF, and E BP as defined in Section 3. The sensitivity of a differential microphone suffers as the distance between the two pressure sensing locations decreases, resulting in an increase in the input sound pressure‐referred noise floor. Mic-Input Pad When operating from ±15V supplies, THAT’s 1570 preamplifier accepts up to +26. You typically use a female XLR connector for the mic-level input. The audio codec can amplify the signal to a reasonable level and already has input pins for a differential microphone. The graph below shows the FFT of the two strain readings. This device offers an integrated high-voltage, programmable microphone bias, and input diagnostic circuitry that allows direct connection to microphone-based automotive systems with full fault diagnostic capability for Apr 21, 2010 · First and second order differential microphone arrays have been used effectively in recording speech and sound signals to mitigate background noise and reverberation. One pin sends the signal as is, and the other pin sends the signal with opposite polarity by referencing its voltage opposite to The LMV1091 is a fully analog dual input, differential output, microphone array amplifier designed to reduce background acoustic noise, while delivering superb speech clarity in voice communications applications. Directional microphones only allow for a fixed directional pattern, but modern DMAs now use digital signal processing Differential Microphone Input With External Gain Setting; Differential Earphone Output Capable of Driving a 32-Load; Programmable Volume Control in Linear Mode; Microphone (MIC) and Earphone (EAR) Mute Functions; Typical Power Dissipation of 0. First, a simple The microphone input circuit consists of two differential input/differential output amplifiers (MIC Amp 1 and MIC Amp 2). Differential: Confusion Reigns. A balanced microphone input consists of a common and 2 signal paths. I. Sep 13, 2023 · The LM833, a dual low-noise, high-performance op-amp from National Semiconductors, serves as a superb choice for constructing a balanced microphone preamplifier. An integrated stereo class D/AB speaker driver and class W headphone driver minimize power consumption during audio playback. 2kΩ resistor between the MICBIAS and the + terminals of each differential microphone. The device features stereo differential microphone inputs that can be connected to either analog or digital micro-phones. The CDB4207 supports the following microphone input types: stereo fully-differential signals (J50 and J56), The full scale input to the device is . If RG = 402 W, we then need RT to be 114. J. Audio signals coming from audio jacks are single ended,but datasheet of module has mentioned that differential audio signals are recommended. The differential microphone diaphragm measures 1 x 2 mm (2) and is fabricated out of polycrystalline silicon. 35 mm) jacks. However, the other two pins are there to compensate for inevitable noise in the raw signal. The measurement is the difference between the signal and the ground or earth at the Microlink. W on each side for 100-W differential output impedance, and we want the input of the FDA to present a 100-W dif-ferential load. The device integrates programable channel gain, digital volume control, a programmable microphone bias voltage, a phase-locked loop (PLL), a programmable high-pass filter (HPF), biquad filters, low-latency filter modes, and Mic Inputs 1-2 Configuration: Class-A discrete differential microphone preamp, pin 2 hot Input impedance: 4 kOhms differential Input level, min gain: 0 dBFS is obtained with a +12 dBu signal at the XLR input Input level, max gain: 0 dBFS is obtained with a -37 dBu signal at the XLR input Frequency response: From 5 Hz to 32 kHz within 0. 8dBu differential input signals at minimum (unity) gain, without clipping its input or output. For double termination, we want the source to provide RS = 50. Another thing I would like to point out is in the block diagram you sent over, it looks like the MIC input is differential. Differential signalling moves the ground reference (and ground loops) out of the signal path, resulting in improved signal Select Start > Settings > System > Sound. Despite the slight design change, the name has stayed the same. Should the microphone be preferably fed trough a series capacitor ? Clipper diodes are implemented at the inputs. In addition, the TS472 has a very low noise microphone bias generator of. The circuit is designed to be operated from a single 9V supply so it is appropriate for battery operated systems. May 1, 2019 · In the simulation section, we study the design of time-domain DMAs up to the third order. Improve your audio recording, live sound reinforcement, broadcasting, and podcasting. The MAX4060 has a fixed gain of 10V/V and is Dec 22, 2023 · Jinfu Wang, Feiran Yang, Junfeng Li, Hongling Sun, Jun Yang; Mode matching-based beamforming with frequency-wise truncation order for concentric circular differential microphone arrays. Mar 11, 2019 · First things first---let's define what XLR means. Choose this configuration when you want to measure high-level signals, noise is not significant, the source of the input is close to the device, and all the input signals are referred to the same common ground. This circuit is designed to work seamlessly with standard 600 Ohm balanced microphones and delivers an approximate gain of 40 dB. Therefore, the output data, SDTO becomes available after 1041/fs cycles of LRCK clock. The device features stereo differential microphone inputs that can be connected to either analog or digital microphones. The diaphragm design is based on the coupled directionally sensitive ears of the fly Ormia ochracea. or Differential configuration: MIC or Line left, positive, or Differential configuration: MIC or Line right, negative 21 IN3_R AI Multifunction Analog Input, or Single-ended configuration: MIC3 or Line 3 right, or Differential configuration: MIC or Line left, negative, or Differential configuration: MIC or Line right, positive 22 LOL AO Left . Aug 12, 2019 · 3. You will also need an differential ADC converter. MIC Amp 1 is a low-noise differential amplifier capable of an externally set gain. 81k) + (R2 ll 6. The device integrates programable channel gain, digital volume control, a programmable microphone bias voltage, a phase-locked loop (PLL), a programmable high-pass filter (HPF), biquad filters, low-latency filter modes, and Jun 15, 2023 · Another way to implement a balanced connection between an ECM-based microphone and a PP-enabled balanced input is with a differential line-driver located close to the microphone. The sensitivity of a differential microphone suffers as the distance between the two pressure sensing locations decreases, resulting in an increase in the input sound pressure-referred May 1, 2008 · A miniature differential microphone is described that has a noise floor that is substantially lower than that of existing devices of comparable size. 5 mm) or 1/4” (6. May 26, 2021 · Line-in and mic-in are audio inputs, but they are indicative of the voltage level of the audio signal. MIC Amp 2 is a differential amplifier with a fixed gain of 6 dB. For example, if you have an A/D board with 16 single-ended inputs, there will be 16 HIGH (+) lines and one LOW (-) line (sometimes called LLGND). 81k) –Therefore, suitable values for R1 & R2 are between 1172 and 1924 ohms. 6dB. the signal source's ground and the Microlink's ground output between the differential input and a single-ended auxiliary microphone amplifier input. May 26, 2021 · Inputs: You have an RCA, quarter-inch jack, or 3. 3V) so you wouldn't be able to do this directly. The sound pressure input-referred noise floor of this miniature differential microphone has been measured to be less than 36 dBA. Differential Microphone Input The following connection is for connecting differential microphones to the audio codec. The buffer creates the signal in-phase with your source, and the inverter creates the signal that is 180° out of phase compared to the original signal. All input configurations are passive and use the recommended DC-blocking capacitors and anti-aliasing filter capacitors. Mar 20, 2018 · A differential microphone array (DMA) is an important option for speech-communication applications because it can effectively reduce the influence of interference and background noise and also has the advantage of compact size (Song and Liu, 2008; Messner, 2013; Elko, 2004; Benesty and Chen, 2013). In Input settings, look at Input volume while speaking into the microphone. The differential gain of the MAX4061/MAX4062 is set with a single resistor. e. This enables a wider operating frequency range and helps to reduce the noise gain of the array Left channel positive differential MIC input / Jack detect input pin 3 LINPUT2 Analogue Input Left channel line input / Left channel positive differential MIC input 4 LINPUT1 Analogue Input Left channel single-ended MIC input / Left channel negative differential MIC input 5 RINPUT1 Analogue Input Right channel single-ended MIC input / J26 Mono differential microphone input Pin 1: MIC1_P Pin 2: MIC1_N Pin 3: GND J27 Mono differential microphone input Pin 1: MIC2_P Pin 2: MIC2_N Pin 3: GND U7 S/PDIF IN Digital optical input U14 S/PDIF OUT Digital optical output J18 HP Stereo single-ended headphone output J24 LINEOUT Differential line output (AC coupled, use J25 for speaker) The TS472 is a differential-input microphone preamplifier optimized for high-performance PDA and notebook audio systems. This microphone supports acoustic inputs up to 131 dB SPL and has a low-frequency response that is flat to 28 Hz. Impedance: Line-in is the highest pre-amplification level in both consumer and professional audio products. Mar 29, 2016 · The basic concept behind differential signalling is based on professional analog audio systems. Its utility stems from its ability to amplify the difference between two input […] Single-ended inputs. This corresponds to 1. Microphone Preamplifier Design 129thAES Convention, Nov 2010. We revisit the standard differential microphone of [1] and propose three algorithmic enhancements. 707Vrms in Single-Ended and 1. An op amp is used as a transimpedance amplifier to convert the output current from the microphone into a signal level voltage. This single-supply microphone pre-amplifier amplifies the output signal of an electret capsule microphone to audio line levels. I am working on a bluetooth module for streaming audio signals. For the output stage, one op-amp from another LM833 is Apr 1, 2020 · The post details regarding a simple microphone (MIC) amplifier circuit which includes built in bass and treble control feature. With single-ended inputs you connect one wire from each signal source to the data acquisition interface - the Microlink. Of course, one pin is a ground reference. Second, the gain of the pre-amp is determined by R2 but the noise gain of the op amp is determined by the ratio of R2 to R1. DAC Output can be configured for either Line Out or Head Phone Load. The LMV1091 has two differential input microphone amplifier channels plus far-field noise suppression (FFNS) circuitry. The differential output can go 2. Second, we describe an efficient algorithm to equalize the distorted directional response of the original algorithm. The AK5730 is in power-down mode until MCLK and LRCK and BICK are input. Dec 13, 2021 · The MAX9867 is an ultra-low power stereo audio codec designed for portable consumer devices such as mobile phones and portable gaming consoles. The WM8994[1] is a highly integrated ultra-low power hi-fi CODEC designed for smartphones and other portable devices rich in multimedia features. The sound pressure input-referred noise floor of this miniature differential microphone has been measured to be less than 36 dBA ⁠. The quarter bridge gauge (single ended) is also affected more by the EMF while the differential input gauge rejects the noise. Two Differential Microphone Inputs; Differential Earphone Outputs and One Single-Ended Earphone Output; Earphone and Microphone Mute; Programmable Transmit, Receive, and Sidetone Paths With Extended Gain and Attenuation Ranges; Programmable for 15-Bit Linear Data or 8-Bit Companded (u-law and A-law) Mode; Supports PCM Clock Rates of 128 kHz and Apr 1, 2009 · The differential microphone diaphragm measures 1 × 2 mm 2 and is fabricated out of polycrystalline silicon. analog modulator The PCM6020-Q1 supports line and microphone inputs, and allows for both single-ended and differential input configurations. 1V amplitude, which is about 780 mVrms. Is this the case? If so, Register 19 is configured for a single-ended input. 2 W; so we select the nearest standard value, 115 W, for RT. DESCRIPTION. Differential microphone arrays, as the name might suggest, measure the spatial derivative of the acoustic pressure field. Signal voltages common to both conductors (the noise) are ignored. 5 mm jack for a line-level input. microphone input The microphone input circuit consists of two differential input/differential output amplifiers (MIC Amp 1 and MIC Amp 2). The thing to be concerned with here, is that you have an 8V mic bias, and its a good possibility that in differential mode that the negative terminal of the mic would approach the ABSMAX voltage for the input pin (AVDD+0. 414Vrms for differential. TI’s PCM6260-Q1 is a Automotive 6-ch audio ADC with integrated programmable mic bias, boost and input diagnostics. The MAX4061 The PCM6x40-Q1 and PCM6x60-Q1 (PCM6xx0-Q1) support line and microphone inputs, and allows for both single-ended and differential input configurations. The analog initialization cycle of ADC starts after exiting the power-down mode. –Differential input impedance is (R1 ll 6. Through internet search, I found this schematic: As the video demonstrates, the quarter bridge gauge (single ended) produces a much noisier reading in the time domain. The issue is that each of this pins has different common mode gain (with respect to the analog ground). The project provides a differential input stage, making the device particularly effective when layout constraints force the microphone amplifier to be physically remote from the ECM microphone. The single-ended line inputs, with configurable preamplifier, can be sent to the Feb 14, 2016 · Little is shown on its data sheet for using inputs differentially. lx tf dt ei it dt do zy ck ca