Overview
The LM5008MM from Texas Instruments is a high-voltage, step-down switching regulator designed for efficient and reliable DC-DC conversion. This device features an integrated 100-V, N-channel buck switch and operates over an input voltage range of 6 V to 95 V. It is particularly suited for applications requiring step-down conversions from 12-V, 24-V, and 48-V supply rails. The LM5008MM is available in 8-pin VSSOP and thermally enhanced 8-pin WSON packages, making it ideal for space-constrained designs.
The regulator uses a hysteretic control scheme with a constant on-time (COT) that varies inversely with the line voltage, ensuring a nearly constant operating frequency. This design eliminates the need for loop compensation, simplifying the implementation and reducing the external component count. The device also includes various protection features such as thermal shutdown, VCC undervoltage lockout, gate drive undervoltage lockout, and an intelligent current limit with forced off-time.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Voltage Range | 6 V to 95 V | V |
| Output Current | Up to 350 mA | A |
| Output Voltage Adjustment | Adjustable | V |
| Switching Frequency | Nearly constant, varies with VIN and RON | Hz |
| Package Types | 8-pin VSSOP, 8-pin WSON | |
| Operating Temperature Range | -40°C to 125°C | °C |
| Thermal Shutdown Temperature | Typically 165°C | °C |
Key Features
- Integrated 100-V, N-channel buck switch
- Internal VCC regulator
- No loop compensation required
- Ultra-fast transient response
- On-time varies inversely with line voltage, maintaining a nearly constant operating frequency
- Adjustable output voltage
- Precision internal reference (2.5 V)
- Low bias current
- Intelligent current limit protection with forced off-time
- Thermal shutdown with automatic recovery
- VCC undervoltage lockout and gate drive undervoltage lockout
- Maximum duty cycle limiter
Applications
- Non-isolated telecommunication buck regulators
- Secondary high-voltage post regulators
- 48-V automotive systems
- 42-V automotive power bus ranges
Q & A
- What is the input voltage range of the LM5008MM?
The input voltage range of the LM5008MM is from 6 V to 95 V.
- What is the maximum output current of the LM5008MM?
The LM5008MM can deliver up to 350 mA of output current.
- Does the LM5008MM require loop compensation?
No, the LM5008MM does not require loop compensation due to its hysteretic control scheme.
- What types of packages are available for the LM5008MM?
The LM5008MM is available in 8-pin VSSOP and 8-pin WSON packages.
- What is the thermal shutdown temperature of the LM5008MM?
The thermal shutdown temperature of the LM5008MM is typically 165°C.
- How does the LM5008MM protect against short circuits?
The LM5008MM includes an intelligent current limit with forced off-time, which ensures short-circuit protection with minimum foldback.
- What is the purpose of the internal VCC regulator in the LM5008MM?
The internal VCC regulator in the LM5008MM provides the necessary voltage for the device's internal circuits.
- Can the output voltage of the LM5008MM be adjusted?
Yes, the output voltage of the LM5008MM is adjustable.
- What are some common applications for the LM5008MM?
Common applications include non-isolated telecommunication buck regulators, secondary high-voltage post regulators, and 48-V automotive systems.
- How does the LM5008MM handle thermal protection?
The LM5008MM includes an internal thermal shutdown circuit that disables the device if the junction temperature exceeds 165°C and resumes operation when the temperature drops below 140°C.
