LB1838M-TLM-E

Due to market price fluctuations, if you need to purchase or consult the price. You can contact us or emial to us:   sales@allicdata.com

The LB1838M-TLM-E is a high-performance motor control and driving IC with a diffusion-junction DMOS power process and a CMOS drive process. It is designed to serve as a power/motor driver using PWM or Lock-type current-controlling techniques, and is particularly suitable for automotive applications.

In terms of its application field, the LB1838M can be used in various kinds of small-scale and medium-size motors, such as fractional Horsepower (HP) motors, Spur and Gearhead Motors, CD-ROM spindle motors, Hard disk drives and so on. The device is available in three different versions, the LB1838MA, LB1838MB and LB1838MC, with different internal configurations to meet the different requirements, such as speed and torque.

The LB1838M works under either PWM or lock-type current-controlling techniques. Under the PWM control, the speed is determined by the duty cycle of the input signal according to the formula velocity = duty cycle × period . The duty cycle is a number from 0 to 1, and in PWM control, this duty cycle adjusts the pulse widths. The device has two boost stages which boosts the output signal up to 16 V. The lock-type current controlling technique needs current sense signal as the input signal, so it requires an additional current sense amplifier to complete the circuit. Comparator and pulse width modulator are also integrated in the device, which helps to complete the current sense and PWM controlling operation.

The detailed operation of the LB1838M can be divided intotwo parts. In the first part, the lower MOSFET is enabled, so a gate voltage is applied to the lower MOSFET, allowing current to flow through the lower MOSFET, turning it into a condutor. Then, the delay circuit starts the upper MOSFET including a logic circuit to rise the voltage of the gate voltage of the upper MOSFET. When the voltage of the gate voltage of upper MOSFET reaches a certain value, the upper MOSFET is also turned on, so current flows through the upper MOSFET as well as the lower MOSFET. This condition is known as Armature Neutral condition.

At the same time, a voltage comparator sense the voltage at the drain source of the upper MOSFET, when it reaches a certain predefined value, the PWM comparator is enabled, so a PWM signal is generated between the OCP output and the RPWM pin. The duty cycle of the PWM signal is dependent on the value set by the RPWM input. In the second stage, the voltage comparator and the level gate control the timing of the device to complete the motor driving operation. The device can also be configured to run in lock-type current-controlling mode in addition to PWM mode by connecting the current sense amplifier to the RPWM pin. In current control mode, the duty cycle of the PWM signal will be varied according to a preset current.

In conclusion, the LB1838M-TLM-E is an excellent motor control and drive IC. It can be used to control small-scale and medium-sized motors, like fractional Horsepower motors, Spur and Gearhead Motors, CD-ROM spindle motors as well as Hard disk drives, and it can be configured to run in either PWM or lock-type current-controlling mode. The device has integrated devices such as comparators, pulse width modulator, delay circuit and logic circuit to help completing the motor driving operation.

The specific data is subject to PDF, and the above content is for reference