Overview
The MC34166TH, part of the MC34166 and MC33166 series, is a high-performance fixed-frequency power switching regulator produced by onsemi. These monolithic devices are optimized for dc-to-dc converter applications and are designed to implement step-down, voltage-inverting, and step-up converters with a minimal number of external components. They feature an internal temperature-compensated reference, a fixed-frequency oscillator, a latching pulse width modulator, a high-gain error amplifier, and a high-current output switch. The devices are particularly suited for applications in automotive, computer, industrial, and cost-sensitive consumer products.
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 | fOSC | 65 | 72 | 81 | kHz |
| Output Switch Current | 3.0 | A | |||
| Operating Junction Temperature | TJ | 150 | °C | ||
| Operating Ambient Temperature (MC34166) | TA | 0 | 70 | °C | |
| Operating Ambient Temperature (MC33166) | TA | -40 | 85 | °C | |
| Thermal Resistance, Junction-to-Ambient (Case 314A, 314B, 314D) | θJA | 65 | °C/W | ||
| Thermal Resistance, Junction-to-Ambient (Case 936A) | 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
- Thermal Shutdown
- Low Power Standby Mode (reduces power supply current to 36 μA)
Applications
The MC34166TH is suitable for a variety of applications, including:
- Automotive systems
- Computer power supplies
- Industrial power systems
- Cost-sensitive consumer electronics
These devices are particularly useful in step-down, voltage-inverting, and step-up converter configurations due to their high performance and minimal external component requirements.
Q & A
- What is the maximum power supply input voltage for the MC34166TH?
The maximum power supply input voltage is 40 V.
- What is the typical oscillator frequency of the MC34166TH?
The typical oscillator frequency is 72 kHz.
- What is the maximum output switch current of the MC34166TH?
The maximum output switch current is in excess of 3.0 A.
- What protective features are included in the MC34166TH?
The device includes cycle-by-cycle current limiting, undervoltage lockout, and thermal shutdown.
- What is the operating ambient temperature range for the MC34166?
The operating ambient temperature range for the MC34166 is 0°C to 70°C.
- What is the operating ambient temperature range for the MC33166?
The operating ambient temperature range for the MC33166 is -40°C to 85°C.
- How does the thermal shutdown feature work in the MC34166TH?
The thermal shutdown feature activates typically at 170°C, forcing the latch into a ‘reset’ state and disabling the output switch to prevent catastrophic failures from overheating.
- What is the purpose of the undervoltage lockout in the MC34166TH?
The undervoltage lockout ensures that the integrated circuit is fully functional before the output stage is enabled, with a threshold of 5.9 V and 0.9 V of hysteresis.
- What is the low power standby mode current of the MC34166TH?
The low power standby mode reduces the power supply current to 36 μA.
- In what package types is the MC34166TH available?
The MC34166TH is available in 5-lead TO-220 type packages and D2PAK surface mount packages.
