Overview
The NCP1055ST136T3G, produced by onsemi, is a highly integrated power management IC designed for high-voltage flyback converters. This device is part of the NCP105X series, which offers a comprehensive solution for modern consumer electronic power supplies. It integrates all the necessary active power, control, logic, and protection circuitry on a single monolithic chip, making it ideal for applications requiring minimal external components and low standby power consumption.
The NCP1055ST136T3G operates directly from a rectified AC line source and features an active startup regulator circuit, eliminating the need for an auxiliary bias winding on the converter transformer. It also includes advanced protection mechanisms such as fault logic with a programmable timer, thermal shutdown, and auto-restart fault detection.
Key Specifications
| Characteristics | Symbol | Min | Max | Unit | |
|---|---|---|---|---|---|
| Drain Voltage Range | VDS | 0 | - | 700 | V |
| Drain Current Peak During Transformer Saturation | IDS(pk) | - | - | 2.0 x Ilim Max | A |
| Oscillator Frequency (VCC = 7.5 V, TJ = 25°C) | fOSC(low) | 113 | - | 145 | kHz |
| Maximum Duty Cycle | D(max) | 74 | 77 | 80 | % |
| Current Limit Threshold (TJ = 25°C) | Ilim | 567 | - | 728 | mA |
| Thermal Shutdown (Junction Temperature Increasing) | Tsd | 140 | - | 160 | °C |
| Undervoltage Lockout Threshold Voltage, VCC Decreasing | VCC(reset) | 4.0 | 4.5 | 5.0 | V |
Key Features
- Startup Circuit: Eliminates the need for a transformer auxiliary bias winding and includes an optional auxiliary bias winding override for lowest standby power applications.
- Protection Mechanisms: Converter output overload and open loop protection, auto-restart fault protection, and IC thermal fault protection.
- Oscillator Configuration: Unique, dual-edge, gated oscillator configuration for extremely fast loop response with double pulse suppression.
- EMI Reduction: Oscillator frequency dithering with controlled slew rate driver for reduced EMI.
- Low Power Consumption: Allows for European Blue Angel compliance.
- Power Switch Circuit: On-chip 700 V power switch circuit and active startup circuit.
- Input Range: Rectified AC line source operation from 85 V to 265 V.
- Input Undervoltage Lockout: With hysteresis.
- Pb-Free and Halide-Free: Compliant with environmental regulations.
Applications
- Cellular Phone Chargers: Efficient and compact power supply solutions.
- Standby Power Supplies for Personal Computers: Low standby power requirements.
- Secondary Bias Supplies for Microprocessor Keep-Alive Supplies: Reliable and efficient power management.
- IR Detectors and Other Consumer Electronics: High integration and low component count.
Q & A
- What is the NCP1055ST136T3G used for?
The NCP1055ST136T3G is used in high-voltage flyback converter applications, particularly in consumer electronic power supplies requiring low standby power consumption.
- What are the key protection mechanisms of the NCP1055ST136T3G?
The device includes converter output overload and open loop protection, auto-restart fault protection, and IC thermal fault protection.
- What is the operating voltage range of the NCP1055ST136T3G?
The device operates from a rectified AC line source ranging from 85 V to 265 V.
- What is the oscillator frequency range of the NCP1055ST136T3G?
The oscillator frequency options are 44 kHz, 100 kHz, and 136 kHz.
- How does the NCP1055ST136T3G reduce EMI?
The device uses oscillator frequency dithering with a controlled slew rate driver to reduce EMI.
- What is the maximum duty cycle of the NCP1055ST136T3G?
The maximum duty cycle is up to 80%.
- What is the thermal shutdown temperature of the NCP1055ST136T3G?
The thermal shutdown temperature ranges from 140°C to 160°C.
- Is the NCP1055ST136T3G Pb-Free and Halide-Free?
Yes, the device is Pb-Free and Halide-Free, complying with environmental regulations.
- What are some typical applications of the NCP1055ST136T3G?
Typical applications include cellular phone chargers, standby power supplies for personal computers, secondary bias supplies for microprocessor keep-alive supplies, and IR detectors.
- What package options are available for the NCP1055ST136T3G?
The device is available in 8-pin dual-in-line and 4-pin SOT-223 packages.
