参数资料
型号: TC105303ECTTR
厂商: Microchip Technology
文件页数: 5/14页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM SOT23A-5
标准包装: 3,000
PWM 型: 控制器
输出数: 1
频率 - 最大: 345kHz
占空比: 100%
电源电压: 2.2 V ~ 10 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: SC-74A,SOT-753
包装: 带卷 (TR)
TC105
3.8
External Switching Transistor
3.8.1
BOARD LAYOUT GUIDELINES
Selection
EXT is a complementary output with a maximum ON
resistance of 22 ? to V DD when high and 19 ? to ground
when low. It is designed to directly drive a P-channel
MOSFET or a PNP bipolar transistor through a base
current limiting resistor (Figure 4-2). A PNP transistor is
recommended in applications where V IN is less than
2.5V. Otherwise, a P-channel MOSFET is preferred as
it affords the highest efficiency because it does not
draw any gate drive current. However, P-channel
MOSFETs are typically more expensive than bipolar
transistors.
P-channel MOSFET selection is determined mainly by
the on-resistance, gate-source threshold, and gate
charge requirements. Also, the drain-to-source and
gate-to-source breakdown voltage ratings must be
greater than V DD MAX . The total gate charge specifica-
tion should be less than 100nC for best efficiency. The
MOSFET must be capable of handling the required
peak inductor current, and should have a very low
on-resistance at that current. For example, an Si9430
MOSFET has a drain-to-source rating of -20V, and a
typical on-resistance r DS ON of 0.07 ? at 2A, with V GS =
-4.5V. Table 4-1 lists suppliers of external components
recommended for use with the TC105.
2002 Microchip Technology Inc.
As with all inductive switching regulators, the TC105
generates fast switching waveforms, which radiate
noise. Interconnecting lead lengths should be mini-
mized to keep stray capacitance, trace resistance and
radiated noise as low as possible. In addition, the GND
pin, input bypass capacitor and output filter capacitor
ground leads should be connected to a single point.
The input capacitor should be placed as close to power
and ground pins of the TC105 as possible. The length
of the EXT trace must also be kept as short as possible.
DS21349B-page 5
相关PDF资料
PDF描述
TC110503ECTTR IC REG CTRLR BST PWM SOT23A-5
TC1121CUA713 IC REG SWITCHD CAP INV ADJ 8MSOP
TC115301EMTTR IC REG BOOST 3V 0.1A SOT89-5
TC1174VOATR IC REG LDO ADJ .3A 8SOIC
TC1187VCT713 IC REG LDO ADJ .15A SOT23A-5
相关代理商/技术参数
参数描述
TC105333ECT 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:PFM/PWM Step-Down DC/DC Controller
TC105333ECTTR 功能描述:开关变换器、稳压器与控制器 PFM/PWM Step-Down RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel
TC1054 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:50 mA, 100 mA and 150 mA CMOS LDOs with Shutdown and ERROR Output
TC1054_07 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:50 mA, 100 mA and 150 mA CMOS LDOs with Shutdown and ERROR Output
TC1054_12 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:50 mA, 100 mA and 150 mA CMOS LDOs with Shutdown and ERROR Output