Overview
The LM2734XMKX/NOPB from Texas Instruments is a high-frequency, PWM step-down DC/DC converter integrated into a compact 6-pin Thin SOT package. This monolithic device is designed to provide efficient local DC/DC conversion with fast transient response and accurate regulation, requiring minimal external components and PCB space. The LM2734XMKX/NOPB supports input voltages from 3V to 20V and can deliver output voltages ranging from 0.8V to 18V, with a maximum output current of 1A. It is particularly suited for applications requiring high power density and efficiency, such as in local point-of-load regulation, core power in hard disk drives, set-top boxes, battery-powered devices, and USB-powered devices.
Key Specifications
| Parameter | Min | |||
|---|---|---|---|---|
| Input Voltage Range | 3 | - | 20 | V |
| Output Voltage Range | 0.8 | - | 18 | V |
| Output Current | - | - | 1 | A |
| Switching Frequency (LM2734X) | 1.2 | 1.6 | 1.9 | MHz |
| Switching Frequency (LM2734Y) | 0.40 | 0.55 | 0.66 | MHz |
| Switch ON Resistance | 300 | - | 600 | mΩ |
| Quiescent Current (Switching) | - | 1.5 | 2.5 | mA |
| Quiescent Current (Shutdown) | - | - | 30 | nA |
| Shutdown Current | - | - | 30 | nA |
| Internal Voltage Reference | 0.784 | 0.800 | 0.816 | V |
| Thermal Shutdown Temperature | - | - | 165 | °C |
Key Features
- Compact Package: 6-pin Thin SOT package, minimizing PCB space.
- High Switching Frequencies: 550 kHz (LM2734Y) and 1.6 MHz (LM2734X), allowing the use of small surface-mount inductors and capacitors.
- Internal Compensation: Simplifies design and reduces the number of external components required.
- Current-Mode Control: Provides high-performance regulation over a wide range of operating conditions.
- Internal Soft Start: Reduces inrush current during startup.
- Pulse-by-Pulse Current Limiting: Protects the output switch from excessive current.
- Thermal Shutdown: Limits total power dissipation by turning off the output switch when the IC junction temperature exceeds 165°C.
- Output Overvoltage Protection: Turns off the internal NMOS control switch if the output voltage exceeds 10% of the internal reference voltage.
- Ultra-Low Shutdown Current: Quiescent current drops to 30 nA in shutdown mode.
Applications
- Local Point-of-Load Regulation: Ideal for powering various components within a system from a central power source.
- Core Power in HDDs: Suitable for hard disk drive applications requiring efficient and compact power solutions.
- Set-Top Boxes: Used in set-top boxes for efficient power conversion.
- Battery-Powered Devices: Suitable for devices powered by batteries, where efficiency and low quiescent current are crucial.
- USB Powered Devices: Applicable in USB-powered devices requiring efficient and compact power conversion.
- DSL Modems: Used in DSL modems for efficient power supply.
- Notebook Computers: Suitable for notebook computers where space and efficiency are important.
Q & A
- What is the input voltage range of the LM2734XMKX/NOPB?
The input voltage range is from 3V to 20V.
- What are the available switching frequencies for the LM2734XMKX/NOPB?
The switching frequencies are 550 kHz (LM2734Y) and 1.6 MHz (LM2734X).
- What is the maximum output current of the LM2734XMKX/NOPB?
The maximum output current is 1A.
- What is the quiescent current in shutdown mode?
The quiescent current in shutdown mode is typically 30 nA.
- Does the LM2734XMKX/NOPB have thermal shutdown protection?
Yes, it has thermal shutdown protection that turns off the output switch when the IC junction temperature exceeds 165°C.
- What type of control mode does the LM2734XMKX/NOPB use?
The LM2734XMKX/NOPB uses current-mode control.
- Does the LM2734XMKX/NOPB have internal soft start and current limiting features?
Yes, it has internal soft start and pulse-by-pulse current limiting features.
- What is the typical switch ON resistance of the LM2734XMKX/NOPB?
The typical switch ON resistance is 300 mΩ.
- What are some common applications of the LM2734XMKX/NOPB?
Common applications include local point-of-load regulation, core power in HDDs, set-top boxes, battery-powered devices, USB-powered devices, DSL modems, and notebook computers.
- How does the LM2734XMKX/NOPB handle output overvoltage protection?
The LM2734XMKX/NOPB turns off the internal NMOS control switch if the output voltage exceeds 10% of the internal reference voltage.
