Overview
The LM2734-Q1, specifically the LM2734XQMKE/NOPB model from Texas Instruments, is a high-frequency, PWM step-down DC/DC converter designed for automotive and other demanding applications. This regulator is housed in a thin 6-pin SOT package, making it ideal for space-constrained designs. It supports a wide input voltage range of 3 V to 20 V and can deliver an output voltage from 0.8 V to 18 V with a maximum output current of 1 A. The device features state-of-the-art 0.5-µm BiCMOS technology, ensuring high power density and efficient operation.
The LM2734-Q1 is easy to use, requiring a minimum of external components, and is supported by Texas Instruments' WEBENCH Power Designer for custom design needs. It offers high-frequency conversion options of either 550 kHz (LM2734Y) or 1.6 MHz (LM2734X), allowing the use of small surface-mount inductors and capacitors. The regulator includes internal soft-start circuitry, pulse-by-pulse current limit, thermal shutdown, and output overvoltage protection, making it a robust solution for various applications.
Key Specifications
| Parameter | Test Conditions | TJ = 25°C | TJ = -40°C to 125°C | Unit |
|---|---|---|---|---|
| Input Voltage Range | 3 V to 20 V | 3 V to 20 V | V | |
| Output Voltage Range | 0.8 V to 18 V | 0.8 V to 18 V | V | |
| Output Current | 1 A | 1 A | A | |
| Switching Frequency | 550 kHz (LM2734Y), 1.6 MHz (LM2734X) | 550 kHz (LM2734Y), 1.6 MHz (LM2734X) | kHz/MHz | |
| Switch ON Resistance | VBOOST - VSW = 3V | 300 mΩ | 300 mΩ | mΩ |
| Quiescent Current (Switching) | 1.5 mA | 1.5 mA | mA | |
| Quiescent Current (Shutdown) | VEN = 0V | 30 nA | 30 nA | nA |
| Feedback Voltage | 0.800 V | 0.800 V | V | |
| Undervoltage Lockout (VIN Rising) | 2.74 V | 2.74 V | V | |
| Thermal Shutdown | 165°C | 165°C | °C |
Key Features
- AEC-Q100 Qualified for Automotive Applications with a device temperature grade of -40°C to +125°C.
- Thin SOT-6 package for space-efficient designs.
- High-frequency operation: 550 kHz (LM2734Y) and 1.6 MHz (LM2734X).
- Internal 300-mΩ NMOS switch.
- Ultra-low shutdown current of 30 nA.
- 0.8-V, 2% internal voltage reference.
- Internal soft-start circuitry to reduce inrush current.
- Current-mode, PWM operation with internal compensation.
- Pulse-by-pulse current limit and thermal shutdown for protection.
- Output overvoltage protection.
Applications
- Automotive systems, including advanced driver assistance systems (ADAS).
- Local point-of-load regulation in various electronic systems.
- High-density power conversion where space is limited.
- Systems requiring high efficiency and fast transient response.
Q & A
- What is the input voltage range of the LM2734-Q1?
The input voltage range is from 3 V to 20 V.
- What are the available switching frequencies for the LM2734-Q1?
The switching frequencies are 550 kHz (LM2734Y) and 1.6 MHz (LM2734X).
- What is the maximum output current of the LM2734-Q1?
The maximum output current is 1 A.
- What is the quiescent current in shutdown mode?
The quiescent current in shutdown mode is typically 30 nA.
- Does the LM2734-Q1 have thermal shutdown protection?
Yes, the LM2734-Q1 has thermal shutdown protection that turns off the output switch when the IC junction temperature exceeds 165°C.
- How is the output voltage set on the LM2734-Q1?
The output voltage is set using a resistive divider connected to the feedback pin, with the equation R1 = (VO - VREF) / R2.
- What is the purpose of the internal soft-start circuitry?
The internal soft-start circuitry forces the output voltage to increase at a controlled rate during startup, reducing inrush current.
- What type of control mode does the LM2734-Q1 use?
The LM2734-Q1 uses current-mode control with internal compensation.
- Is the LM2734-Q1 suitable for automotive applications?
Yes, the LM2734-Q1 is AEC-Q100 qualified for automotive applications.
- How can the boost voltage be derived for the LM2734-Q1?
The boost voltage can be derived from the input voltage, output voltage, an external distributed voltage rail, or a shunt or series Zener diode.
