TNY253/254/255：高效节能离线式开关电源解决方案

需积分: 6 174 浏览量更新于2024-07-31 收藏 499KB PDF 举报

"TNY253/254/255是高效能、低功率的离线式开关电源解决方案，适用于多种应用场合，如手机充电器、PC、电视、VCR的备用电源、公用仪表和无绳电话。" TNY253/254/255系列芯片是专为低功耗、高性能的离线电源设计的，旨在提供比RCC（电阻-电容-晶体管）电路、分立式PWM（脉宽调制）方案以及其他集成或混合解决方案更低的成本。这些芯片能够作为大体积线性适配器的经济有效的替代品，显著减少组件数量，简化电路设计，降低整体成本。该系列的特点包括： 1. 简单的ON/OFF控制：无需环路补偿设备，使得设计更为简洁。 2. 无需偏置绕组：简化变压器设计，进一步降低成本。 3. 支持简单的RC型EMI滤波器：在通用输入或115VAC输入时，可支持高达2W或4W的功率输出。 4. 极高的能效：在115VAC或230VAC空载条件下，仅消耗30/60毫瓦的功率，符合Blue Angel、Energy Star、Energy 2000和200mW欧洲手机待机要求，每年可节省$1至$4的能源费用（以$0.12/kWh计算）。 5. 广泛的应用范围：特别适合于手机充电器、PC和电视的备用电源、公用仪表以及无绳电话等产品。在性能方面，TNY253/254/255展现出卓越的特性： 1. 高压驱动：适合于充电器应用，能提供稳定且高效的电源。 2. 非常高的环路带宽：确保了优秀的瞬态响应，实现快速启动，几乎无过冲现象。 3. 电流限制操作：能够有效地抑制过载情况，提高了系统的稳定性与可靠性。 TNY253/254/255系列芯片通过其独特的设计特点和出色的性能，为低功耗、高效率电源解决方案提供了新的选择，尤其在需要节省成本和空间，同时保证性能的场合，它们是理想的解决方案。在设计离线式电源系统时，考虑使用TNY253/254/255可以优化成本与性能之间的平衡，同时满足严格的能源效率标准。

7/01

TNY253/254/255

Figure 4. TinySwitch Operation at Heavy Load. Figure 5. TinySwitch Operation at Medium Load.

DRAIN

CLOCK

DRAIN

MAX

PI-2255-061298

DRAIN

CLOCK

DRAIN

MAX

PI-2259-061298

percentage of cycles will conduct to support the power

consumption of the power supply.

The response time of TinySwitch ON/OFF control scheme is

very fast compared to normal PWM control. This provides high

line ripple rejection and excellent transient response.

Power Up/Down

TinySwitch requires only a 0.1 µF capacitor on the BYPASS

pin. Because of the small size of this capacitor, the power-up

delay is kept to an absolute minimum, typically 0.3 ms (Figure7).

Due to the fast nature of the ON/OFF feedback, there is no

overshoot at the power supply output. During power-down, the

power MOSFET will switch until the rectified line voltage

drops to approximately 12 V. The power MOSFET will then

remain off without any glitches (Figure 8).

Bias Winding Eliminated

TinySwitch does not require a bias winding to provide power to

the chip. Instead it draws the power directly from the DRAIN

pin (see Functional Description above). This has two main

benefits. First for a nominal application, this eliminates the cost

of an extra bias winding and associated components. Secondly,

for charger applications, the current-voltage characteristic often

allows the output voltage to fall to low values while still

delivering power. This type of application normally requires a

forward-bias winding which has many more associated

components, none of which are necessary with TinySwitch.

Current Limit Operation

Each switching cycle is terminated when the DRAIN current

reaches the current limit of the TinySwitch. For a given primary

inductance and input voltage, the duty cycle is constant.

However, duty cycle does change inversely with the input

voltage providing “voltage feed-forward” advantages: good

line ripple rejection and relatively constant power delivery

independent of the input voltage.

44 kHz Switching Frequency (TNY253/254)

Switching frequency (with no cycle skipping) is set at 44kHz.

This provides several advantages. At higher switching

frequencies, the capacitive switching losses are a significant

proportion of the power losses in a power supply. At higher

frequencies, the preferred snubbing schemes are RCD or diode-

Zener clamps. However, due to the lower switching frequency

of TinySwitch , it is possible to use a simple RC snubber (and

even just a capacitor alone in 115VAC applications at powers

levels below 4W).

Secondly, a low switching frequency also reduces EMI filtering

requirements. At 44kHz, the first, second and third harmonics

are all below 150kHz where the EMI limits are not very

restrictive. For power levels below 4W it is possible to meet

worldwide EMI requirements with only resistive and capacitive

filter elements (no inductors or chokes). This significantly

reduces EMI filter costs.

Finally, if the application requires stringent noise emissions

(such as video applications), then the TNY253/254 will allow

more effective use of diode snubbing (and other secondary

snubbing techniques). The lower switching frequency allows

RC snubbers to be used to reduce noise, without significantly

impacting the efficiency of the supply.

剩余19页未读，继续阅读

xhc12345

粉丝: 0
资源: 3

TNY253/254/255：高效节能离线式开关电源解决方案

TNY267P构成的开关电源电路分析与检修

TNY267GN产品

TNY274 PDF

rtx51tny.rar_rtx51tny

Conf_tny.A51

tny4412_12.16.patch

TNY375－380中文资料

TNY256原理及性能分析

tny264充电器原理图

discord-bot:TNY Discord机器人

最新资源