UC28025是TI公司的一款PWM与谐振控制器产品，UC28025是经济型高速 PWM 控制器，本页介绍了UC28025的产品说明、应用、特性等，并给出了与UC28025相关的TI元器件型号供参考。
UC28025 - 经济型高速 PWM 控制器 - PWM与谐振控制器 - 离线隔离型DC/DC控制器和转换器 - TI公司（Texas Instruments，德州仪器）
The UC28023 and UC28025 are fixed-frequency PWM controllers optimized for high-frequency switched-mode power supply applications. The UC28023 is a single output PWM for single-ended topologies while the UC28025 offers dual alternating outputs for double-ended and full bridge topologies.
Targeted for cost effective solutions with minimal external components, UC2802x include an oscillator, a temperature compensated reference, a wide band width error amplifier, a high-speed current-sense comparator and high-current active-high totem-pole outputs to directly drive external MOSFETs.
Protection circuitry includes a current limit comparator with a 1-V threshold, a TTL compatible shutdown port, and a soft-start pin which will double as a maximum duty cycle clamp. The logic is fully latched to provide jitter free operation and prohibit multiple pulses at an output. An undervoltage lockout section with 800 mV of hysteresis assures low start-up current. During undervoltage lockout, the outputs are high impedance. Particular care was given to minimizing propagation delays through the comparators and logic circuitry while maximizing bandwidth and slew rate of the error amplifier.
Devices are available in the industrial temperature range of –40°C to 105°C. Package offerings are 16-pin SOICW (DW), or 16-pin PDIP (N) packages.
- Peak Current Mode, Average Current Mode, or Voltage Mode (with Feed-Forward) Control Methods
- Practical Operation Up to 1 MHz
- 50-ns Propagation Delay to Output
- ±1.5-A Peak Totem Pole Outputs
- 9-V to 30-V Nominal Operational Voltage Range
- Wide Bandwidth Error Amplifier
- Fully Latched Logic with Double Pulse Suppression
- Pulse-by-Pulse Current Limiting
- Programmable Maximum Duty Cycle Control
- Under-Voltage Lockout with Hysteresis
- Trimmed 5.1-V Reference with UVLO
- Same Functionality as UC3823 and UC3825
- APPLICATIONS
- Off-Line and DC/DC Power Supplies
- Converters Using Voltage Mode, Peak Current Mode, or Average Current Mode Control Methods
- Single-Ended or Two-Switch Topology Designs
