Overview
The LM2611, produced by Texas Instruments, is a current-mode PWM inverting switching regulator. This device operates within a wide input voltage range of 2.7 V to 14 V and is capable of producing a regulated negative output voltage. The LM2611 features a high switching frequency of 1.4 MHz, which allows for the use of small and low-cost inductors and capacitors. It is particularly useful in applications requiring low voltage ripple and high efficiency.
The device is available in a compact 5-pin SOT-23 package and includes a shutdown pin to reduce quiescent current to less than 1 µA when not in use. This makes it suitable for battery-powered devices where power conservation is crucial.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Supply Voltage | 2.7 | - | 14 | V |
| Switching Frequency | 1.3 | 1.4 | 1.5 | MHz |
| Output Voltage Range | -36 VIN(MAX) | - | - | V |
| Output Current Limit (Grade A) | - | 1.2 | - | A |
| Output Current Limit (Grade B) | - | 0.9 | - | A |
| RDS(ON) (Grade A) | - | 0.5 | - | Ω |
| RDS(ON) (Grade B) | - | 0.7 | - | Ω |
| Shutdown Current | - | <1 | - | µA |
| Operating Junction Temperature | -40 | - | 125 | °C |
| Package Type | - | - | 5-pin SOT-23 | - |
Key Features
- High switching frequency of 1.4 MHz, allowing for small and low-cost inductors and capacitors.
- Low RDS(ON) DMOS FET for high efficiency.
- Wide input voltage range: 2.7 V to 14 V.
- Low shutdown current: less than 1 µA.
- Internal compensation and cycle-by-cycle current limiting.
- Simple output voltage setting using a two-resistor divider.
- Thermal shutdown protection.
- Pulse-skipping (hysteretic) mode at low loads to maintain regulation.
- Compact 5-pin SOT-23 package.
Applications
- MR Head Bias
- Digital Camera CCD Bias
- LCD Bias
- GaAs FET Bias
- Positive to Negative Conversion
Q & A
- What is the typical switching frequency of the LM2611?
The typical switching frequency of the LM2611 is 1.4 MHz.
- What is the input voltage range for the LM2611?
The input voltage range for the LM2611 is from 2.7 V to 14 V.
- How do you set the output voltage of the LM2611?
The output voltage of the LM2611 can be set using a two-resistor divider connected to the negative feedback (NFB) pin.
- What is the maximum current limit for Grade A and Grade B devices?
For Grade A, the maximum current limit is 1.2 A, and for Grade B, it is 0.9 A.
- What is the typical RDS(ON) for Grade A and Grade B devices?
For Grade A, the typical RDS(ON) is 0.5 Ω, and for Grade B, it is 0.7 Ω.
- What is the shutdown current of the LM2611?
The shutdown current of the LM2611 is less than 1 µA.
- What type of package does the LM2611 come in?
The LM2611 comes in a 5-pin SOT-23 package.
- What is the operating junction temperature range for the LM2611?
The operating junction temperature range for the LM2611 is from -40°C to 125°C.
- Does the LM2611 have thermal shutdown protection?
Yes, the LM2611 has thermal shutdown protection that activates if the junction temperature exceeds 163°C.
- What happens in pulse-skipping (hysteretic) mode?
In pulse-skipping mode, the output voltage increases slightly as the device skips pulses to maintain regulation at low loads.
