Overview
The LM43603PWPT from Texas Instruments is a high-efficiency synchronous step-down DC-DC converter designed to drive up to 3 A of load current from an input voltage ranging from 3.5 V to 36 V (with an absolute maximum of 42 V). This regulator is part of a family that includes options for 0.5-A, 1-A, and 2-A load current in pin-to-pin compatible packages. It is known for its exceptional efficiency, output accuracy, and dropout voltage, making it suitable for a wide range of applications.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Input Voltage (VIN to PGND) | -0.3 | 42 | V | |
| Output Voltage (VOUT) | 1 | 28 | V | |
| Output Current (IOUT) | 0 | 3 | A | |
| Operating Junction Temperature (TJ) | -40 | 125 | °C | |
| Quiescent Current (IQ-SW) | 27 | µA | ||
| Switching Frequency (FOSC-DEFAULT) | 425 | 500 | 580 | kHz |
| High-Side MOSFET ON-Resistance (RDS-ON-HS) | 120 | mΩ | ||
| Low-Side MOSFET ON-Resistance (RDS-ON-LS) | 65 | mΩ | ||
| Thermal Shutdown Threshold | 160 | °C |
Key Features
- High efficiency at light load (DCM and PFM)
- Meets EN55022/CISPR 22 EMI standards
- Integrated synchronous rectification
- Adjustable frequency range: 200 kHz to 2.2 MHz (500 kHz default)
- Frequency synchronization to external clock
- Internal compensation
- Stable with almost any combination of ceramic, polymer, tantalum, and aluminum capacitors
- Power-good flag
- Soft start into a pre-biased load
- Internal soft-start: 4.1 ms, extendable by external capacitor
- Output voltage tracking capability
- Precision enable to a program system UVLO
- Output short circuit protection with hiccup mode
- Overtemperature thermal shutdown protection
Applications
- Industrial power supplies
- Telecommunications systems
- Sub-AM band automotive systems
- General purpose wide VIN regulation
- High efficiency point-of-load regulation
Q & A
- What is the input voltage range of the LM43603PWPT?
The input voltage range is from 3.5 V to 36 V, with an absolute maximum of 42 V. - What is the maximum output current of the LM43603PWPT?
The maximum output current is 3 A. - What are the typical switching frequencies of the LM43603PWPT?
The default switching frequency is 500 kHz, but it can be adjusted from 200 kHz to 2.2 MHz. - Does the LM43603PWPT meet any EMI standards?
Yes, it meets EN55022/CISPR 22 EMI standards. - What is the quiescent current of the LM43603PWPT in regulation mode?
The quiescent current is typically 27 µA. - What protection features does the LM43603PWPT have?
It includes output short circuit protection with hiccup mode, overtemperature thermal shutdown protection, and cycle-by-cycle current limiting. - Can the LM43603PWPT be synchronized with an external clock?
Yes, it supports frequency synchronization to an external clock. - What is the internal soft-start time of the LM43603PWPT?
The internal soft-start time is 4.1 ms, and it can be extended using an external capacitor. - What types of capacitors are compatible with the LM43603PWPT?
It is stable with almost any combination of ceramic, polymer, tantalum, and aluminum capacitors. - What is the thermal shutdown threshold of the LM43603PWPT?
The thermal shutdown threshold is 160°C.
