Overview
The LM5161PWPR, produced by Texas Instruments, is a synchronous-buck regulator converter designed to operate over a wide input voltage range of 4.5-V to 100-V and support a maximum load current of 1-A. This device integrates high-side and low-side MOSFETs, eliminating the need for an external Schottky diode. The LM5161 employs a constant-ON-time control scheme, which requires no external loop compensation and supports high step-down ratios with fast transient response. It features an internal feedback amplifier that maintains ±1% output voltage regulation over the entire operating temperature range.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Input Voltage (VIN to AGND) | -0.3 | - | 100 | V |
| Maximum Junction Temperature | -40 | - | 150 | °C |
| Storage Temperature (Tstg) | -65 | - | 150 | °C |
| Maximum Load Current | - | - | 1 | A |
| Feedback Reference Voltage (VREF) | 1.975 | 2 | 2.015 | V |
| Thermal Shutdown Threshold (TSD) | - | - | 175 | °C |
| Junction-to-Ambient Thermal Resistance (RθJA) | - | - | 39.3 | °C/W |
Key Features
- Wide 4.5-V to 100-V input voltage range
- Integrated high-side and low-side switches; no Schottky diode required
- 1-A maximum load current
- Constant ON-time control; no external loop compensation required
- Fast transient response
- Selectable discontinuous conduction mode (DCM) at light load
- Continuous conduction mode (CCM) supports multi-output Fly-Buck applications
- No external ripple injection circuit needed (at FPWM = 0)
- Nearly constant switching frequency; adjustable up to 1 MHz
- Programmable soft-start time
- Prebias start-up capability
- Peak current limiting protection
- Adjustable input undervoltage lockout (UVLO) and hysteresis
- ±1% feedback voltage reference
- Thermal shutdown protection
Applications
- Industrial programmable logic controllers
- IGBT gate drive bias supply
- Telecom DC-DC primary and secondary side bias
- E-meter power line communication
- Low-power (<12W), isolated DC-DC (Fly-Buck) applications
Q & A
- What is the input voltage range of the LM5161?
The input voltage range of the LM5161 is 4.5-V to 100-V.
- What is the maximum load current supported by the LM5161?
The LM5161 supports a maximum load current of 1-A.
- Does the LM5161 require an external Schottky diode?
No, the LM5161 integrates high-side and low-side switches, eliminating the need for an external Schottky diode.
- What control scheme does the LM5161 use?
The LM5161 uses a constant ON-time control scheme, which requires no external loop compensation.
- Can the LM5161 operate in discontinuous conduction mode (DCM)?
- What is the typical feedback reference voltage of the LM5161?
The typical feedback reference voltage (VREF) is 2 V.
- How is the switching frequency of the LM5161 adjusted?
The switching frequency can be adjusted up to 1 MHz using the RON pin resistor.
- Does the LM5161 have thermal shutdown protection?
- What package type is the LM5161 available in?
The LM5161 is available in a 14-pin HTSSOP package with an exposed pad.
- What are some common applications of the LM5161?
Common applications include industrial programmable logic controllers, IGBT gate drive bias supply, telecom DC-DC bias, and low-power isolated DC-DC (Fly-Buck) applications.
