Summary of LTC3892 – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller
The LTC3892/LTC3892-1/LTC3892-2 is a high-performance dual step-down DC/DC switching regulator controller designed for automotive and industrial power systems. It drives N-channel synchronous MOSFETs with out-of-phase operation to minimize noise and input capacitance requirements. Key features include a wide 4.5V to 60V input range, adjustable gate drive levels, low quiescent current, and selectable operating modes like pulse skipping or burst mode for efficiency at light loads.
Parts used in the LTC3892 Project:
- LTC3892 Controller
- LTC3892-1 Controller
- LTC3892-2 Controller
- N-channel Synchronous Power MOSFETs
- Input Capacitors
- Output Capacitors
- Logic-Level FETs
- Standard-Level FETs
Features
- Wide VIN Range: 4.5V to 60V (65V Abs Max)
- Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 99% • VIN
- Adjustable Gate Drive Level 5V to 10V (OPTI-DRIVE)
- No External Bootstrap Diodes Required
- Low Operating IQ: 29μA (One Channel On)
- Selectable Gate Drive UVLO Thresholds
- Out-of-Phase Operation Reduces Required Input Capacitance and Power Supply Induced Noise
- Phase-Lockable Frequency: 75kHz to 850kHz
- Selectable Continuous, Pulse Skipping or Low Ripple Burst Mode® Operation at Light Loads
- Selectable Current Limit (LTC3892/LTC3892-2)
- Very Low Dropout Operation: 99% Duty Cycle
- Power Good Output Voltage Monitors (LTC3892/LTC3892-2)
- Low Shutdown IQ: 3.6μA
- Small 32-Lead 5mm × 5mm QFN Package (LTC3892/ LTC3892-2) or TSSOP Package (LTC3892-1)
Description
The LTC®3892/LTC3892-1/LTC3892-2 is a high performance dual step-down DC/DC switching regulator controller that drives all N-channel synchronous power MOSFET stages. Power loss and noise are minimized by operating the two controller output stages out-of-phase.
The gate drive voltage can be programmed from 5V to 10V to allow the use of logic or standard-level FETs and to maximize efficiency. Internal switches in the top gate drivers eliminate the need for external bootstrap diodes.
A wide 4.5V to 60V input supply range encompasses a wide range of intermediate bus voltages and battery chemistries. Output voltages up to 99% of VIN can be regulated. OPTILOOP® compensation allows the transient response and loop stability to be optimized over a wide range of output capacitance and ESR values.
The 29μA no-load quiescent current extends operating run time in battery powered systems. For a comparision of the LTC3892 to the LTC3892-1 and LTC3892-2, see Table 1 in the Pin Functions section of this data sheet.
Applications
- Automotive and Industrial Power Systems
- Distributed DC Power Systems
- High Voltage Battery Operated Systems
For more Details: LTC3892 – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller
- What is the maximum input voltage for the LTC3892?
The device supports a wide input supply range from 4.5V to 60V with a 65V absolute maximum rating. - Can the gate drive voltage be adjusted?
Yes, the gate drive voltage can be programmed from 5V to 10V to allow the use of logic or standard-level FETs. - How does the controller reduce input noise?
Out-of-phase operation reduces the required input capacitance and minimizes power supply induced noise. - Does the LTC3892 require external bootstrap diodes?
No, internal switches in the top gate drivers eliminate the need for external bootstrap diodes. - What are the available operating modes at light loads?
The controller offers selectable Continuous, Pulse Skipping, or Low Ripple Burst Mode Operation at light loads. - Is the frequency adjustable?
Yes, the phase-lockable frequency is selectable between 75kHz and 850kHz. - What is the shutdown quiescent current?
The device has a very low shutdown IQ of 3.6μA. - Which packages are available for this controller?
The LTC3892 and LTC3892-2 come in a small 32-Lead 5mm × 5mm QFN Package, while the LTC3892-1 uses a TSSOP Package.
