Model No: LM5117PMHX/NOPB
Texas Instruments LM5117PMHX/NOPB
Manufacturer: Texas Instruments
SEMICON NO.: LM5117PMHX/NOPB
Package: 20-HTSSOP
Stock: In stock
Description: Buck Controller Positive 1 Output
SEMICON NO.: LM5117PMHX/NOPB
Package: 20-HTSSOP
Stock: In stock
Description: Buck Controller Positive 1 Output
Quantity :
| Mfr | Texas Instruments |
| Device Type | Synchronous Buck Controller |
| Output Type | Transistor Driver |
| Function | Step-Down |
| Output Configuration | Positive |
| Topology | Buck |
| Number of Outputs | 1 |
| Output Phases | 1 |
| Synchronous Rectifier | Yes |
| Voltage - Supply (Vcc/Vdd) | 5.5 V to 65 V |
| Output Voltage Range | 0.8 V to 62 V |
| Switching Frequency | 200 kHz, 480 kHz, 750 kHz (Max) |
| Peak Gate Drive | 3.3 A |
| Operating Temperature | -40°C to +125°C |
| Package | 20-HTSSOP |
| Mounting Type | Surface Mount |
| Compliance | RoHS Compliant |
The LM5117PMHX/NOPB is a high-voltage, synchronous buck controller from Texas Instruments, designed in a thermally enhanced 20-HTSSOP package for driving external N-channel MOSFETs in step-down DC-DC converter applications. It operates from a wide input voltage range of 5.5V to 65V, making it suitable for industrial, automotive, and telecom power systems. The controller features a constant on-time (COT) valley current mode control architecture, which provides fast transient response and simplifies loop compensation while maintaining high efficiency across a wide load range.
Key Features and Highlights:
● Wide Input Voltage Range: Supports operation from 5.5V to 65V, allowing direct connection to 12V, 24V, or 48V industrial bus voltages
● Valley Current Mode Control: Employs an emulated current mode control scheme that offers the benefits of current mode control (fast transient response, inherent pulse-by-pulse current limiting)
● High-Frequency Operation: Capable of switching frequencies up to 750 kHz (typical 500 kHz), enabling the use of smaller external inductors and capacitors
● Integrated High-Current Gate Drivers: Features separate high-side and low-side gate drivers capable of sourcing and sinking 2A and 3A peak currents respectively, allowing efficient driving of large power MOSFETs
● Advanced Protection & Programmability: Includes adjustable undervoltage lockout (UVLO), programmable soft-start, external frequency synchronization, and optional diode emulation mode
Application Scenarios:
● Industrial Power Systems: Used in PLCs, motor drives, and distributed power architectures converting 24V or 48V bus voltages to lower voltages like 5V, 3.3V, or 12V for logic and sensors.
● Automotive and Heavy-Duty Equipment: Powers infotainment systems, ADAS modules, and control units from the vehicle battery (12V/24V), handling load-dump and cold-crank conditions.
● Telecommunications Infrastructure: Provides point-of-load (POL) conversion in servers, routers, and base stations from a 48V backplane to various lower supply rails.
● General-Purpose High-Voltage Buck Regulators: Suitable for any application requiring a robust, efficient step-down converter from an input source up to 65V.
Frequently Asked Questions (FAQ):
Q1: What is the purpose of the diode emulation mode (DEMB pin), and when should it be used?
A: Diode emulation mode forces the controller to operate in discontinuous conduction mode (DCM) at light loads by disabling the low-side MOSFET synchronous rectification.
Q2: How do I set the output voltage and switching frequency for the LM5117?
A: The output voltage is set by an external resistor divider from VOUT to the FB (feedback) pin. The switching frequency is primarily determined by the resistor connected from the RT pin to ground; a higher resistor value results in a lower frequency.
Compatible Alternative step-down converter List
● LM5118: A similar high-voltage buck controller from Texas Instruments with peak current mode control architecture instead of valley current mode, offering an alternative control method for different design priorities.
● TPS40210: A versatile non-synchronous (requires an external catch diode) wide-input (4.5V to 52V) current-mode controller, serving as an alternative for cost-sensitive or lower-current designs where synchronous rectification is not required.
● LT3845: A high-voltage (up to 60V) synchronous buck controller from Analog Devices featuring peak current mode control and high switching frequency capability, providing a performance-competitive alternative.
Key Features and Highlights:
● Wide Input Voltage Range: Supports operation from 5.5V to 65V, allowing direct connection to 12V, 24V, or 48V industrial bus voltages
● Valley Current Mode Control: Employs an emulated current mode control scheme that offers the benefits of current mode control (fast transient response, inherent pulse-by-pulse current limiting)
● High-Frequency Operation: Capable of switching frequencies up to 750 kHz (typical 500 kHz), enabling the use of smaller external inductors and capacitors
● Integrated High-Current Gate Drivers: Features separate high-side and low-side gate drivers capable of sourcing and sinking 2A and 3A peak currents respectively, allowing efficient driving of large power MOSFETs
● Advanced Protection & Programmability: Includes adjustable undervoltage lockout (UVLO), programmable soft-start, external frequency synchronization, and optional diode emulation mode
Application Scenarios:
● Industrial Power Systems: Used in PLCs, motor drives, and distributed power architectures converting 24V or 48V bus voltages to lower voltages like 5V, 3.3V, or 12V for logic and sensors.
● Automotive and Heavy-Duty Equipment: Powers infotainment systems, ADAS modules, and control units from the vehicle battery (12V/24V), handling load-dump and cold-crank conditions.
● Telecommunications Infrastructure: Provides point-of-load (POL) conversion in servers, routers, and base stations from a 48V backplane to various lower supply rails.
● General-Purpose High-Voltage Buck Regulators: Suitable for any application requiring a robust, efficient step-down converter from an input source up to 65V.
Frequently Asked Questions (FAQ):
Q1: What is the purpose of the diode emulation mode (DEMB pin), and when should it be used?
A: Diode emulation mode forces the controller to operate in discontinuous conduction mode (DCM) at light loads by disabling the low-side MOSFET synchronous rectification.
Q2: How do I set the output voltage and switching frequency for the LM5117?
A: The output voltage is set by an external resistor divider from VOUT to the FB (feedback) pin. The switching frequency is primarily determined by the resistor connected from the RT pin to ground; a higher resistor value results in a lower frequency.
Compatible Alternative step-down converter List
● LM5118: A similar high-voltage buck controller from Texas Instruments with peak current mode control architecture instead of valley current mode, offering an alternative control method for different design priorities.
● TPS40210: A versatile non-synchronous (requires an external catch diode) wide-input (4.5V to 52V) current-mode controller, serving as an alternative for cost-sensitive or lower-current designs where synchronous rectification is not required.
● LT3845: A high-voltage (up to 60V) synchronous buck controller from Analog Devices featuring peak current mode control and high switching frequency capability, providing a performance-competitive alternative.
