Overview
The MC34166T, part of the MC34166 and MC33166 series, is a high-performance fixed frequency power switching regulator produced by onsemi. These devices are optimized for dc-to-dc converter applications and are designed to implement step-down and voltage-inverting configurations with a minimal number of external components. They can also be used cost-effectively in step-up converter applications. The MC34166T operates as a fixed frequency, voltage mode regulator and includes all the active functions necessary for these converter types.
Key Specifications
| Characteristic | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Power Supply Input Voltage | VCC | - | - | 40 | V |
| Switch Output Voltage Range | VO(switch) | -1.5 | - | + Vin | V |
| Oscillator Frequency (VCC = 7.5 V to 40 V) | fOSC | 65 | 72 | 79 | kHz |
| Output Switch Current | - | - | 3.0 | A | |
| Current Limit Threshold | Ipk(switch) | 3.3 | 4.3 | 6.0 | A |
| Operating Junction Temperature | TJ | - | - | 150 | °C |
| Operating Ambient Temperature | TA | 0 | - | 70 | °C |
| Thermal Resistance, Junction-to-Ambient | θJA | - | - | 70 | °C/W |
Key Features
- Output Switch Current in Excess of 3.0 A
- Fixed Frequency Oscillator (72 kHz) with On-Chip Timing
- Provides 5.05 V Output without External Resistor Divider
- Precision 2% Reference
- 0% to 95% Output Duty Cycle
- Cycle-by-Cycle Current Limiting
- Undervoltage Lockout and Thermal Shutdown
- Low Power Standby Mode reducing power supply current to 36 μA
Applications
The MC34166T is suitable for various applications including:
- Automotive systems
- Computer and industrial power supplies
- Cost-sensitive consumer products
- Step-down and voltage-inverting converters
- Step-up converter applications
Q & A
- What is the maximum output switch current of the MC34166T?
The maximum output switch current is in excess of 3.0 A.
- What is the operating frequency of the oscillator in the MC34166T?
The oscillator operates at a fixed frequency of 72 kHz.
- What is the precision of the internal reference voltage in the MC34166T?
The internal reference voltage has a precision of 2% and provides a 5.05 V output without an external resistor divider.
- What protective features are included in the MC34166T?
The device includes cycle-by-cycle current limiting, undervoltage lockout, and thermal shutdown.
- What is the thermal shutdown temperature for the MC34166T?
The thermal shutdown typically occurs at 170°C.
- What is the power supply current in standby mode for the MC34166T?
In standby mode, the power supply current is reduced to 36 μA.
- What are the typical operating ambient temperature ranges for the MC34166T?
The operating ambient temperature range is from 0°C to +70°C.
- What types of packages are available for the MC34166T?
The MC34166T is available in D2PAK surface mount and TO-220 packages.
- What are some common applications for the MC34166T?
Common applications include automotive systems, computer and industrial power supplies, and cost-sensitive consumer products.
- How does the MC34166T handle overcurrent protection?
The device features cycle-by-cycle current limiting to protect against overcurrent conditions.
