on October 17th 331

Understanding the LM2907 Key Features and Uses

The LM2907 is a versatile frequency-to-voltage converter widely used in applications that demand precise signal processing, such as automotive speed sensing and industrial machinery monitoring. Its specially designed pin configuration enhances both performance and ease of integration, making it a reliable choice for you. This article digs into the practical aspects of using the LM2907, from connecting it correctly for optimal voltage stability to ensuring protection against noise interference. Whether in automotive systems or consumer electronics, the LM2907 stands out for its adaptability and efficiency.

Catalog

LM2907 Detailed Analysis

The LM2907 is a notable member of a versatile family of frequency-to-voltage converters. It utilizes a high-gain operational amplifier/comparator, exhibiting a refined ability to activate relays, lights, or other actuators once the input frequency exceeds a predetermined threshold. The incorporation of advanced charge pump technology allows it to double the frequency while maintaining minimal ripple, which is a distinguishing feature. This frequency doubling is principally advantageous in scenarios demanding high signal fidelity, such as in automotive diagnostics and industrial automation.

The LM2907-8 and LM2917-8 variants are equipped with extensive input protection features. These safeguards prevent overvoltage and mitigate electrical noise, ensuring their reliable operation even in the most demanding environments. Both models come with a floating transistor output that pairs well with tachometers. The design supports currents up to 50 mA and can handle a maximum voltage (VCE) of 28V. These features have demonstrated their reliability in applications necessitating steadfast and unwavering performance, such as in automotive engines and heavy machinery.

The LM2907 family offers two distinct configurations. The 8-pin version is specially designed for single-speed sensors and basic buffered frequency-to-voltage conversions. This straightforward configuration serves as an ideal solution for applications requiring limited signal processing, making it invaluable in systems where space and simplicity are dominant, like consumer electronics and basic RPM sensing.

LM2907 Pin Configuration

CAD Model of LM2907

LM2907 Symbol

LM2907 Footprint

LM2907 3D Model

Key Features of the LM2907

Feature	Description
Direct ground reference tachometer input interface	Provides a direct connection to ground for tachometer inputs.
Variable reluctance sensor compatibility	Supports variable reluctance sensors for detecting rotational speed.
Operational amplifier/comparator with floating transistor output	Includes an operational amplifier/comparator with a transistor output that is not tied to ground, allowing more flexible circuit designs.
50 mA receiver or power supply	Can drive receivers, relays, solenoids, meters, or LEDs with up to 50 mA current while maintaining low-ripple frequency multiplier behavior.
Tachometer with built-in hysteresis	The built-in hysteresis helps stabilize readings by minimizing oscillations in differential or ground reference input setups.
Built-in Zener LM2917	Features a Zener diode, improving voltage regulation and protection, enhancing the overall reliability of the device.
0.3% typical linearity	Provides high accuracy in frequency-to-voltage conversion with a typical linearity of 0.3%.
Ground reference protection	Fully protects ground reference tachometer inputs from damage caused by voltage swings that exceed VCC or drop below ground potential.

LM2907 Technical Specifications

Here is the table with the technical specifications, attributes, and parameters of the Texas Instruments LM2907M.

Type	Parameter
Lifecycle Status	NRND (Last Updated: 5 days ago)
Mounting Type	Surface Mount
Package / Case	14-SOIC (0.154, 3.90mm Width)
Surface Mount	Yes
Number of Pins	14
Packaging	Tube
JESD-609 Code	e0
Part Status	Not For New Designs
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Number of Terminations	14
ECCN Code	EAR99
Type	Frequency to Voltage Converter
Terminal Finish	Tin/Lead (Sn/Pb)
Max Operating Temperature	85°C
Min Operating Temperature	-40°C
HTS Code	8542.39.00.01
Terminal Position	Dual
Terminal Form	Gull Wing
Peak Reflow Temperature	235°C
Number of Functions	1
Supply Voltage	12V
Terminal Pitch	1.27mm
Frequency	10kHz
Base Part Number	LM2907
Pin Count	14
Temperature Grade	Industrial
Max Supply Voltage	28V
Min Supply Voltage	12V
Linearity	±0.3%
Positive Input Voltage-Max	10.5V
Height	1.75mm
Length	8.65mm
Width	3.91mm
Thickness	1.58mm
Radiation Hardening	No
RoHS Status	Non-RoHS Compliant
Lead Free	Contains Lead

LM2907 Layout Guidelines

Benefits of the LM2907

Simplified Signal Grounding

The LM2907 device comes with a ground-referenced zero-frequency output, allowing straightforward interfacing with other circuit components. This feature simplifies the design process, reducing the risk of errors related to signal grounding and enhancing reliability.

Ease of Use and Quick Implementation

The LM2907 is designed for quick implementation in various frequency-to-voltage conversion tasks. This simplicity proves invaluable in time-sensitive projects where rapid turnaround becomes a serious factor. The device's intuitive configuration ensures even individuals with limited experience can effectively harness its capabilities, boosting efficiency in both the prototyping and production stages.

Frequency Doubling with Minimal Components

Another notable attribute of the LM2907 is its capability to double frequency with a single RC network. This functionality offers a streamlined solution for signal frequency manipulation scenarios, reducing the need for additional components. Subsequently, it lowers material costs and decreases circuit complexity. In practical applications like tachometers and frequency modulation systems, this feature elevates performance without demanding extensive resources or intricate configurations.

Versatility and Efficiency in Production

These advantages highlight the prowess of the LM2907 in handling frequency signal processes, making it a valuable asset for you. It merges simplicity with functionality, ensuring robust and reliable operation in diverse applications. From a practical standpoint, the LM2907 often leads to more streamlined project timelines and reduced costs. This efficiency affirms the device's applicability, enhancing its reputation as a reliable component in various engineering tasks.

LM2907 Functional Diagram

Alternatives to LM2907

Part Number	Description	Manufacturer
LM2907MEP	IC VOLTAGE-FREQUENCY CONVERTER, PDSO14, PLASTIC, SOP-14, Analog Special Function Converter	Texas Instruments
LM2907MXEP	IC VOLTAGE-FREQUENCY CONVERTER, PDSO14, PLASTIC, SOP-14, Analog Special Function Converter	National Semiconductor Corporation
LM2907D14R	VOLTAGE-FREQUENCY CONVERTER, PDSO14	Texas Instruments
LM2907M/NOPB	IC VOLTAGE-FREQUENCY CONVERTER, PDSO14, PLASTIC, SOIC-14, Analog Special Function Converter	National Semiconductor Corporation
LM2907D14	VOLTAGE-FREQUENCY CONVERTER, PDSO14	Texas Instruments
LM2907MX/NOPB	Frequency to Voltage Converter for ground or supply referred load up to 50-mA; 14-SOIC -40 to 85	Texas Instruments
LM2907MX	Frequency to Voltage Converter for ground or supply referred load up to 50-mA; 14-SOIC -40 to 85	Texas Instruments

LM2907 Use Cases

Overspeed and Low-Speed Detection

The LM2907 is adept at detecting overspeed and low-speed conditions in industrial machinery. Its precision in measuring varying frequencies can avert mechanical failures by shutting down equipment running at unsafe speeds, thus safeguarding the machinery and enhancing operational reliability. In the automotive world, the LM2907 enhances safety by providing dependable feedback for engine management systems. By monitoring the engine's rotational speed, it ensures the engine operates efficiently across different driving conditions. This not only boosts performance but also prevents engine damage.

Frequency-to-Voltage Conversion (Tachometers)

The LM2907 is celebrated for its role in frequency-to-voltage conversion, mostly in tachometers. In automotive diagnostics, accurate measurement of engine revolutions per minute (RPM) through tachometers is active. The LM2907 facilitates this by converting rotational speed into voltage signals, which helps fine-tune engine parameters for optimal performance. By enabling precise voltage outputs, the LM2907 ensures that tachometers display accurate readings, which is major for both analog and digital instruments.

Speedometers

Speedometers rely on the LM2907 to convert frequency signals from wheel sensors into voltage. This ensures that vehicles display accurate speed, which is useful for adherence to traffic laws and enhancing driver situational awareness. The reliability of the LM2907's conversion process supports its use in traditional analog and modern digital speedometers alike, catering to a variety of vehicle technologies.

Breaker Point Dwell Meters

For vehicles with older ignition systems, the LM2907 plays a notable role in breaker point dwell meters. These meters measure the dwell angle, ensuring the ignition coils are energized correctly. This is insistent for maintaining efficient engine firing and optimal fuel combustion.

Handheld Tachometers

In fields like automotive repair and HVAC systems, handheld tachometers equipped with the LM2907 provide quick and precise rotational speed readings. These portable devices enhance technicians' ability to diagnose and resolve issues efficiently, minimizing downtime.

Governor Cruise Controls

The LM2907's role in governor cruise controls allows for meticulous speed regulation in vehicles. Converting frequency data from the drive system helps maintain consistent speeds, which is mostly beneficial for heavy-duty vehicles and long-distance travel, contributing to fuel efficiency and driving comfort.

Car Door Locks and Clutch Controls

In modernizing car door locks and clutch controls, the LM2907 monitors actuator speeds to ensure synchronized and timely operations. This precision bolsters the reliability and security of these systems, enhancing overall vehicle safety features.

Horn Controls

For horn controls, the LM2907 aids in generating and regulating the horn's frequency. This ensures a consistent and effective audible signal, complying with regulatory standards and providing reliable warning sounds.

Touch or Sound-Activated Switches

The LM2907's ability to convert the frequency of touch or sound impulses into voltage signals is useful for touch or sound-activated switches. This technology enhances the responsiveness and dependability of control systems in areas such as home automation and security, ensuring high sensitivity and accuracy.

Typical Applications

Breaker Points Dwell Meter

Minimal Component Tachometer Configuration

Zener-Regulated Frequency to Voltage Converter

Speed-Switch Circuit

LM2907 Physical Layout

Insights into Texas Instruments (TI)

Texas Instruments (TI) holds a distinguished place as an American semiconductor manufacturer, headquartered in the vibrant city of Dallas, Texas. Celebrated for its relentless innovation and expansive product array, TI designs a broad spectrum of analog and embedded processing chips. Over 80% of its revenue stems from these chips. The applications for these chips span numerous industries including automotive, industrial, and personal electronics.

TI offers more than just analog and embedded processing chips. It is also a trailblazer in digital light processing technology, greatly impacting projectors and digital cinema. Additionally, TI has made notable advancements in educational technology with products such as calculators and microcontrollers. These tools benefit millions of students and professionals involved in STEM fields.

By 2016, TI had secured an impressive 45,000 patents across the globe. This commitment to innovation and continuous improvement situates TI among the top 10 semiconductor companies worldwide by sales, emphasizing its influence in the tech industry. Patents not only protect TI's innovations but also drive ongoing research and development. A considerable portion of TI's triumph is linked to the practical applications of its technology. For example, embedded processing chips play a serious role in the advancement of smart devices, enhancing the Internet of Things (IoT) ecosystem.