LMD18245T/NOPB Description
The LMD18245 full-bridge power amplifier incorporates all the circuit blocks required to drive and control current in a brushed type DC motor or one phase of a bipolar stepper motor. The multi-technology process used to build the device combines bipolar and CMOS control and protection circuitry with DMOS power switches on the same monolithic structure. The LMD18245 controls the motor current via a fixed off-time chopper technique.
An all DMOS H-bridge power stage delivers continuous output currents up to 3A (6A peak) at supply voltages up to 55V. The DMOS power switches feature low RDS(ON) for high efficiency, and a diode intrinsic to the DMOS body structure eliminates the discrete diodes typically required to clamp bipolar power stages.
An innovative current sensing method eliminates the power loss associated with a sense resistor in series with the motor. A four-bit digital-to-analog converter (DAC) provides a digital path for controlling the motor current, and, by extension, simplifies implementation of full, half and microstep stepper motor drives. For higher resolution applications, an external DAC can be used.
LMD18245T/NOPB Features
DMOS Power Stage Rated at 55V and 3A Continuous
Low RDS(ON) of Typically 0.3Ω per Power Switch
Internal Clamp Diodes
Low-loss Current Sensing Method
Digital or Analog Control of Motor Current
TTL and CMOS Compatible Inputs
Thermal Shutdown (Outputs Off) at TJ = 155°C
Overcurrent Protection
No Shoot-Through Currents
15-lead Package
LMD18245T/NOPB Functional Block Diagram
LMD18245T/NOPB Connection Diagram
LMD18245T/NOPB Pinout Descriptions
Pin 1, OUT 1: Output node of the first half H-bridge.
Pin 2, COMP OUT: Output of the comparator. If the voltage at CS OUT exceeds that provided by the DAC, the comparator triggers the monostable.
Pin 3, RC: Monostable timing node. A parallel resistorcapacitor network connected between this node and ground sets the monostable timing pulse at about 1.1 RC seconds.
Pin 5, PGND: Ground return node of the power bridge. Bond wires (internaI) connect PGND to the tab of the TO-220 package.
Pins 4 and 6 through 8, M4 through M1: Digital inputs of the DAC. These inputs make up a four-bit binary number with M4 as the most significant bit or MSB. The DAC provides an analog voltage directly proportional to the binary number applied at M4 through M1.
Pin 9, VCC: Power supply node.
Pin 10, BRAKE: Brake logic input. Pulling the BRAKE input logic-high activates both sourcing switches of the power bridge — effectively shorting the load. Shorting the load in this manner forces the load current to recirculate and decay to zero.
Pin 11, DIRECTION: Direction logic input. The logic level at this input dictates the direction of current flow in the load.
Pin 12, SGND: Ground return node of all signal level circuits.
Pin 13, CS OUT: Output of the current sense amplifier. The current sense amplifier sources 250 μA (typical) per ampere of total forward current conducted by the upper two switches of the power bridge.
Pin 14, DAC REF: Voltage reference input of the DAC. The DAC provides an analog voltage equal to VDAC REF × D/16, where D is the decimal equivalent (0–15) of the binary number applied at M4 through M1.
Pin 15, OUT 2: Output node of the second half H-bridge.
LMD18245T/NOPB Applications
Full, Half and Microstep Stepper Motor Drives
Stepper Motor and Brushed DC Motor Servo Drives
Automated Factory, Medical and Office Equipment
LMD18245T/NOPB Product Parameter
|
Manufacturer |
Texas |
Manufacturer's Part # |
LMD18245T/NOPB |
|
Categories |
Integrated Circuits (ICs) |
Sub-Categories |
PMIC - Motor Drivers, Controllers |
|
Part Status |
Active |
Motor Type - Stepper |
Bipolar |
|
Motor Type - AC, DC |
Brushed DC |
Function |
Driver - Fully Integrated, Control and Power Stage |
|
Output Configuration |
Half Bridge (2) |
Interface |
Parallel |
|
Technology |
Bi-CMOS, DMOS |
Step Resolution |
1, 1/2 |
|
Applications |
General Purpose |
Voltage - Supply |
12V~55V |
|
Voltage - Load |
12V~55V |
Operating Temperature |
-40°C~150°C TJ |
|
Mounting Type |
Through Hole |
Package / Case |
TO-220-15 Formed Leads |
|
Factory Lead Time |
6 Weeks |
Lifecycle Status |
ACTIVE (Last Updated: 4 days ago) |
|
Mount |
Through Hole |
Number of Pins |
15 |
|
Packaging |
Tube |
Pbfree Code |
yes |
|
Number of Terminations |
15 |
Terminal Finish |
Matte Tin (Sn) |
|
Subcategory |
Motion Control Electronics |
Terminal Position |
ZIG-ZAG |
|
Supply Voltage |
42V |
Base Part Number |
LMD18245 |
|
Output Current-Max |
6A |
Collector Emitter Voltage (VCEO) |
55V |
|
Max Collector Current |
3A |
Motor Type |
Brushed |
|
Height |
4.62mm |
Length |
20.015mm |
|
Width |
17.501mm |
Thickness |
4.496mm |
|
Radiation Hardening |
No |
Lead Free |
Lead Free |
|
Output Voltage |
55V |
Analog IC - Other Type |
STEPPER MOTOR CONTROLLER |
|
Operating Supply Current |
8mA |
Number of Channels |
2 |
|
Logic Function |
AND |
Additional Feature |
CONTAINS DC MOTOR DRIVER |
LMD18245T/NOPB Manufacturer
Texas Instruments is a semiconductor multinational company in Texas, USA. It is famous for developing, manufacturing, and selling semiconductor and computer technology. It is mainly engaged in innovative digital signal processing and analog circuits. In addition to the semiconductor business, it also provides solutions including sensing and control, educational products and digital light source processing. Texas Instruments (TI) is headquartered in Dallas, Texas, USA, and has manufacturing, design or sales organizations in more than 25 countries.
