Overview
The LM2703MFX-ADJ/NOPB is a micropower step-up DC/DC converter produced by Texas Instruments. This device is packaged in a small 5-lead SOT-23 package, making it ideal for space-conscious portable applications. The LM2703 features a current-limited, fixed off-time control scheme that conserves operating current, ensuring high efficiency over a wide range of load conditions. It supports an input voltage range of 2.2V to 7V and can produce output voltages up to 21V, making it versatile for various applications.
Key Specifications
| Parameter | Min | Typ | Max | Units |
|---|---|---|---|---|
| Input Voltage Range (VIN) | 2.2 | 7.0 | V | |
| Switch Current Limit (ICL) | 275 | 350 | 400 | mA |
| Switch RDSON | 0.7 | 1.6 | Ω | |
| Switch Off Time (TOFF) | 400 | ns | ||
| Feedback Trip Point (VFB) | 1.189 | 1.237 | 1.269 | V |
| Shutdown Current (IQ) | 0.01 | 2.5 | µA | |
| Junction Temperature (TJ) | -40 | 125 | °C | |
| Thermal Resistance (θJA) | 220 | °C/W |
Key Features
- Adjustable output voltage up to 21V
- Current-limited, fixed off-time control scheme for high efficiency
- Low 400ns off-time allows use of tiny, low-profile inductors and capacitors
- Input undervoltage lockout (UVP) with a threshold of 1.8V
- Shutdown current as low as 0.01µA
- Small 5-lead SOT-23 package for space-conscious designs
- Supports driving up to 4 white LEDs from a single Li-Ion battery
Applications
- LCD bias supplies
- White LED back-lighting, especially in cellular phones
- Handheld devices
- Digital cameras
- Portable applications requiring low current and high efficiency
Q & A
- What is the input voltage range of the LM2703?
The input voltage range of the LM2703 is from 2.2V to 7V.
- What is the maximum output voltage that the LM2703 can produce?
The LM2703 can produce output voltages up to 21V.
- How does the LM2703 conserve operating current?
The LM2703 uses a current-limited, fixed off-time control scheme to conserve operating current.
- What is the typical shutdown current of the LM2703?
The typical shutdown current of the LM2703 is 0.01µA.
- What type of package does the LM2703 come in?
The LM2703 comes in a small 5-lead SOT-23 package.
- What is the maximum junction temperature for the LM2703?
The maximum junction temperature for the LM2703 is 125°C.
- How is the output voltage adjusted on the LM2703?
The output voltage is adjusted by selecting appropriate values for R1 and R2 in the feedback network.
- What is the purpose of the SHDN pin on the LM2703?
The SHDN pin is used for shutdown control and is active low, meaning the device is enabled when the pin is above 1.1V and disabled when it is below 0.3V.
- What type of capacitors are recommended for the output of the LM2703?
Low ESR capacitors, such as multilayer ceramic capacitors, are recommended to minimize output voltage ripple.
- What are some typical applications of the LM2703?
The LM2703 is typically used in LCD bias supplies, white LED back-lighting, handheld devices, digital cameras, and other portable applications requiring low current and high efficiency.
