A4405屬于集成電路（IC）的線性穩(wěn)壓器控制器。由Allegro MicroSystems制造生產(chǎn)的A4405穩(wěn)壓器 - 線性 + 開關(guān)此產(chǎn)品族中的產(chǎn)品用于構(gòu)建執(zhí)行 DC-DC 轉(zhuǎn)換或電壓調(diào)節(jié)功能的電路，采用的是開關(guān)模式和線性穩(wěn)壓器功能的組合。雖然具體的拓?fù)涓鞑幌嗤?，但此類產(chǎn)品的主要目的是將開關(guān)模式技術(shù)的效率優(yōu)勢與線性穩(wěn)壓技術(shù)的低噪聲特性結(jié)合在一起。

描述 Description

The A4405 is an automotive power management IC that uses a high frequency constant on-time 5.45 V pre-regulator to supply two internal 5 V linear regulators and a 3.3 V linear DMOS driver. Designed to supply CAN and microprocessor power supplies in high temperature environments, the A4405 is ideal for under hood applications. Efficient operation is achieved by using a buck pre-regulator to efficiently drop the input voltage

before supplying the linear regulators; this reduces power dissipation and increases overall regulator efficiency.

Features and Benefits

? AEC Q100 Grade 0 qualified

? Internal buck pre-regulator followed by LDO outputs

? 5.5 to 36 V VIN operating range (50 V maximum);

for start/stop, cold crank, and load dump requirements

? 2.2 MHz constant on-time buck regulator

? Valley current sensing achieves shortest buck on-times

? 50 V absolute maximum input voltage for surges

? 5.5 to 46 V input voltage range

? ?40oC to 150oC junction temperature range

? Power-on reset (NPOR pin) with adjustable rising delay

? 5 V (V5P pin) internal low dropout tracking linear regulator with both overcurrent foldback and short-to-battery protection

? 5 V (V5 pin) internal low dropout linear regulator with overcurrent foldback protection

? 3.3 V (V33 pin) external linear regulator DMOS driver with a programmable current limit (up to 500 mA) and overcurrent foldback protection

? Logic enable input (ENB pin)

? Ignition enable input (ENBAT pin)

? Ignition status indicator (ENBATS pin)

? Buck pulse-by-pulse overcurrent protection

? Buck LX short circuit protection (latched)

? Missing asynchronous diode protection (latched)

? Switcher (VREG pin), 3.3 V (V33 pin), and charge pump (VCP pin) undervoltage lockout protection (UVLO)

? Thermal shutdown protection (TSD)

Applications:

Automotive Control Modules, such as:

? Electronic power steering (EPS)

? Transmission control (TCU)

? Antilock braking (ABS)

? Emissions control