- 您现在的位置：买卖IC网 > PDF目录383914 > TC1303B-FM0EMFTR (Microchip Technology Inc.) 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output PDF资料下载
参数资料
| 型号： | TC1303B-FM0EMFTR |
| 厂商： | Microchip Technology Inc. |
| 英文描述： | 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output |
| 中文描述： | 500毫安同步降压稳压器，300 mA的LDO具有电源就绪输出 |
| 文件页数： | 16/30页 |
| 文件大小： | 441K |
| 代理商： | TC1303B-FM0EMFTR |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页当前第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页
TC1303B
DS21949A-page 16
2005 Microchip Technology Inc.
4.0
DETAILED DESCRIPTION
4.1
Device Overview
The TC1303B combines a 500 mA synchronous buck
regulator with a 300 mA LDO and a power-good output.
This unique combination provides a tiny, low-cost
solution for applications that require two or more
voltage rails. The buck regulator can deliver high-
output current over a wide range of input-to-output
voltage ratios while maintaining high efficiency. This is
typically used for the lower-voltage, high-current
processor core. The LDO is a minimal parts-count
solution,
(single-output
regulated voltage for an auxiliary rail. The typical LDO
dropout voltage (137 mV @ 200 mA) allows the use of
very low input-to-output LDO differential voltages,
minimizing the power loss internal to the LDO pass
transistor. A power-good output is provided, indicating
that the LDO output is in regulation (TC1303B).
Additional features include independent shutdown
inputs, UVLO, overcurrent and overtemperature
shutdown.
capacitor),
providing
a
4.2
Synchronous Buck Regulator
The synchronous buck regulator is capable of supply-
ing a 500 mA continuous output current over a wide
range of input and output voltages. The output voltage
range is from 0.8V (min) to 4.5V (max). The regulator
operates in three different modes and automatically
selects the most efficient mode of operation. During
heavy load conditions, the TC1303B buck converter
operates at a high, fixed frequency (2.0 MHz) using
current mode control. This minimizes output ripple and
noise (less than 8 mV peak-to-peak ripple) while main-
taining high efficiency (typically > 90%). For standby or
light load applications, the buck regulator will automat-
ically switch to a power-saving Pulse Frequency
Modulation (PFM) mode. This minimizes the quiescent
current draw on the battery, while keeping the buck
output voltage in regulation. The typical buck PFM
mode current is 38 μA. The buck regulator is capable of
operating at 100% duty cycle, minimizing the voltage
drop from input to output for wide input battery-
powered applications. For fixed-output voltage applica-
tions, the feedback divider and control loop compensa-
tion components are integrated, eliminating the need
for external components. The buck regulator output is
protected against overcurrent, short circuit and over-
temperature. While shut down, the synchronous buck
N-channel and P-channel switches are off, so the L
X
pin is in a high-impedance state (this allows for
connecting a source on the output of the buck regulator
as long as its voltage does not exceed the input
voltage).
4.2.1
FIXED FREQUENCY PWM MODE
While operating in Pulse Width Modulation (PWM)
mode, the TC1303B buck regulator switches at a fixed
2.0 MHz frequency. The PWM mode is suited for higher
load current operation, maintaining low output noise
and high conversion efficiency. PFM to PWM mode
transition is initiated for any of the following conditions.
Continuous inductor current is sensed
Inductor peak current exceeds 100 mA
The buck regulator output voltage has dropped
out of regulation (step load has occurred)
The typical PFM-to-PWM threshold is 80 mA.
4.2.2
PFM MODE
PFM mode is entered when the output load on the buck
regulator is very light. Once detected, the converter
enters the PFM mode automatically and begins to skip
pulses to minimize unnecessary quiescent current
draw by reducing the number of switching cycles per
second. The typical quiescent current for the switching
regulator is less than 35 μA. The transition from PWM
to PFM mode occurs when discontinuous inductor
current is sensed, or the peak inductor current is less
than 60 mA (typ.). The typical PWM to PFM mode
threshold is 30 mA. For low input-to-output differential
voltages, the PWM to PFM mode threshold can be low
due to the lack of ripple current. It is recommended that
V
IN1
be one volt greater than V
OUT1
for PWM to PFM
transitions.
4.3
Low Drop Out Regulator (LDO)
The LDO output is a 300 mA low-dropout linear regula-
tor that provides a regulated output voltage with a
single 1 μF external capacitor. The output voltage is
available in fixed options only, ranging from 1.5V to
3.3V. The LDO is stable using ceramic output capaci-
tors that inherently provide lower output noise and
reduce the size and cost of the regulator solution. The
quiescent current consumed by the LDO output is
typically less than 20 μA, with a typical dropout voltage
of 137 mV at 200 mA. The LDO output is protected
against overcurrent and overtemperature.
相关PDF资料 |
PDF描述 |
|---|---|
| TC1303B-FM0EUN | 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output |
| TC1303B-FM0EUNTR | 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output |
| TC1303B-FM1EMF | 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output |
| TC1303B-FM1EMFTR | 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output |
| TC1303B-FM1EUN | 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TC1303B-IA0EMF | 功能描述:低压差稳压器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| TC1303B-IA0EMFTR | 功能描述:低压差稳压器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| TC1303B-IA0EUN | 功能描述:低压差稳压器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| TC1303B-IA0EUNTR | 功能描述:低压差稳压器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| TC1303B-PA0EMF | 功能描述:低压差稳压器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
发布紧急采购，3分钟左右您将得到回复。