LMD18200T/NOPB IC

Technical Specifications of LMD18200T/NOPB

Datasheet	LMD18200T/NOPB datasheet
Category	Integrated Circuits (ICs)
Family	PMIC – Motor Drivers, Controllers
Manufacturer	Texas Instruments
Series	–
Packaging	Tube
Part Status	Active
Motor Type – Stepper	Bipolar
Motor Type – AC, DC	Brushed DC
Function	Driver – Fully Integrated, Control and Power Stage
Output Configuration	Low Side (2)
Interface	Parallel
Technology	Bi-CMOS, DMOS
Step Resolution	–
Applications	General Purpose
Current – Output	3A
Voltage – Supply	12 V ~ 55 V
Voltage – Load	12 V ~ 55 V
Operating Temperature	-40°C ~ 150°C (TJ)
Mounting Type	Through Hole
Package / Case	TO-220-11 (Formed Leads)
Supplier Device Package	TO-220-11

LMD18200T/NOPB Description

To control mechanical systems, you may rely on the LMD18200, a 3A H-Bridge. A single silicon chip is used in the multi-technology architecture, which integrates DMOS power devices with bipolar and CMOS control circuits. The LMD18200 is a fantastic option for driving DC and stepper motors due to its greatest output current of up to 6A. Low-loss output current detection is made possible by incorporating an advanced circuit.

LMD18200T/NOPB Features

• Delivers Constant Output of Up to 3A.
• It uses supply voltages up to 55V to operate.
• Poor RDS (ON) Generally, each switch costs 0.33 at 3A.
• Compatible Inputs for TTL and CMOS.
• No current that can “shoot through.”
• At 170 °C, thermal shutdown (outputs off).
• Clamp Diodes inside.
• Shorted Load Defense.
• Internal Charge Pump with the Ability to Bootstrap Externally.

LMD18200T/NOPB Applications

• Stepper Motor Drives And DC
• Velocity Servomechanisms and Position
• Numerically Controlled Machinery
• Computer Printers and Plotters

LMD18200T/NOPB Detailed Description

● Types of PWM Signals

The LMD18200 easily connects to several PWM signal types. The next paragraphs explain using the component with two more common PWM types.

● Signal Transition Requirements

It’s recommended that the rising and falling edges of input signals not be aligned for optimal performance of internal logic. The input signals for direction, braking, and pulse width modulation (PWM) should have a minimum 1 s delay between transitions. If you want to err on caution, you should wait at least 500 ns before starting the second transition after the first one ends.

● Using the Current Sense Output

A sensitivity of 377 A per output ampere is available at the CURRENT SENSE output (pin 8). To ensure maximum precision and linearity of this signal, it is recommended that the resistor value connecting pin 8 to ground be set so that no more than 5V is produced at pin 8. Allowed voltage levels up to 12V. It’s important to remember that the current sense circuitry doesn’t account for freewheeling currents (which are essentially recirculated currents). Because of this, only the currents at the top sourcing outputs are measured.

● Using the Thermal Warning Flag

The THERMAL FLAG has an open collector transistor for its output (pin 9). This enables the user to adjust the output signal swing’s logic high level to match the system’s needs precisely, and it allows for a wired OR connection of the thermal warning flag outputs from multiple LMD18200’s. This output normally drives the interrupt input of the system controller. When an interruption occurs, the system should be programmed to respond appropriately, for as by decreasing the load current or shutting down in a controlled fashion. The flag pin will accept up to 12V of electricity.

● Supply Bypassing

Voltage transients across system stray inductance may become problematic due to the high rates of current change seen during switching transitions. In most cases, you’ll want to connect a high-quality capacitor or capacitors between the VS Power Supply (Pin 6) and GROUND to avoid a ground loop and keep the power flowing uninterrupted (Pin 7). For the best results, use a ceramic high-frequency capacitor with a 1 F value. Transients on the supply pin should be kept below the device’s Absolute Maximum Rating. A voltage suppressor (transorb) like the P6KE62A is recommended from supply to ground when using the chip at supply voltages higher than 40V. When a voltage suppressor is present, it is not necessary to use a ceramic capacitor. Keep in mind that more supply bypass capacitance is needed to soak up the recirculating currents of the inductive loads when driving large load currents (typically at least 100 F per Amp of load current).

● Current Limiting

The LMD18200 includes integrated current limiting protective circuitry. Shorted loads can cause significant surge currents across any power equipment; thus, it’s crucial to consider this possibility’s consequences. Overload conditions are detected by the protection circuitry, which promptly turns off the power device if the current exceeds a preset level (often around 10 Amps). Either locked rotors or shorted motor windings bring on most overload problems in motor driving applications. If a current surge occurs, the inductance of the motor (and any series inductance in the VCC supply line) helps to dampen the surge to a level where the LMD18200 is unharmed.

Once powered down, the device’s control circuitry will repeatedly attempt to restart it. If the fault condition is resolved, regular operation can resume instantly, thanks to this function. Yet, while the problem persists, the gadget will go into and out of thermal shutdown cycles. Supply bypassing strategies are necessary because this can cause voltage transients on the VCC line. Any power supply will fail in its most critical state in the event of a long-term, direct short from an output to ground (also known as a “screwdriver” short). For the brief time it takes for the protection circuitry to cut off the power device, this condition can cause a spike of current through the power device on the order of 15 Amps, requiring the die and package to dissipate up to 500 Watts of power. Safety measures should be taken because this energy can be damaging, especially at higher working voltages (>30V). Using 1 square inch of copper on the PCB is common practice to heat sink the VCC supply pin (pin 6).

● Bootstrap Capacitors and The Internal Charge Pump

Each high-side (source) DMOS power device requires a gate voltage roughly 8 volts (V) higher than the supply voltage to turn on. An on-board charge pump generates the gate drive voltage.

● Internal Protection Diodes

It is essential to safeguard switching power devices against the sizeable voltage transients when switching current through inductive loads. The LMD18200 has four separate switches, each with its own protection diode to limit transient voltages below the diode’s threshold value (which is well below the positive supply or ground). Once the transient has passed, the diodes’ ability to recover in reverse is crucial. The power switches must carry the additional reverse recovery current of the diodes, and the diodes must be able to exit conduction swiftly. When tested with a full 6A of forward current via the diode, its reverse recovery time is often under 70 ns, and its reverse recovery current is normally 1A. When subjected to the same 4A of reverse current, the recovery period for the sinking devices is typically 100 ns.

Conclusion

The LMD18200 is a remarkable H-Bridge because of its great performance and precision in a wide range of motion control uses. Due to its high level of sophistication and array of built-in safeguards, it is an excellent choice for demanding projects requiring efficiency and adaptability. Yet, particular signal transition conditions must be met to provide the best results. ICRFQ is worth looking into if you’re in the market for premium electronic parts. Contact us today to learn more about the LMD18200 and other electronic components that can elevate your designs to the next level. Don’t hesitate to take advantage of the resources available and start your next project confidently.

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