HJ42131A/ HJ42131B high temperature three-way low dropout voltage regulator with power-on reset

HJ42131A/HJ42131B is a high-temperature three-channel low-dropout voltage regulator suitable for TMS320F2812/F2810, featuring power-on/power-off reset functionality. It includes three low-dropout linear voltage regulators of 1.8V, 1.5V, and 3.3V, as well as a power-on/power-off reset circuit. The maximum output current of the HJ42131A three-channel low-dropout voltage regulator is 300mA, while the HJ42131B can reach up to 700mA. When TMS320F2812/F2810 is operating normally, in addition to the need for sequential power-up of 3.3V and 1.8V, a power-on/power-off reset signal: /XRS must also be provided by the user. This port serves as both an input and an output and contains a 20μA pull-down constant current source internally. During the power-up process, /XRS should remain low for at least 1mS after the 1.8V reaches 1.5V. During this time, all ports are in an indeterminate state, and the six sets of clocks (oscout, ACLK, sysclk, MCLK, ICLK, RTICLK) within the system have not yet been established. This can increase Icc in certain logic gates internally and cause logic contention; both situations can lead to voltage surges at the power supply during power-up, affecting the lifespan of TMS320F2812/F2810 and causing significant impact on the upstream power supplies of 3.3V and 1.8V. If a '0' level is applied to /XRS during power-up, only oscout will work among the six sets of clocks while the other five will not operate at this time, minimizing power consumption. Once the core and peripheral supplies reach normal values and stable clocks are established, releasing reset will not cause voltage surges during power-up. During power-down, /XRS should change from '1' to '0' no less than 8μS before the 1.8V drops to 1.5V. Its function is to correctly reset the internal flash memory of TMS320F2812/F2810 so that CPU can access flash normally during subsequent power-ups. The power-on/power-off reset consists of a high-performance comparator, switching transistor, precision delay network, and hold network that generates a reset signal required by TMS320F2812/F2810 by detecting input and output from LDO supplying TMS320F2812/F2810 (see timing diagram for details). This circuit is made using improved thick-film integrated circuit technology with characteristics such as small size, high reliability, low thermal resistance etc., avoiding defects like "purple spots" caused by gold-aluminum bonding at high temperatures and improving long-term reliability in high-temperature environments with a maximum operating temperature reaching up to 200℃. In application, simply connect this device's /RST with TMS320F2812/F2810's /XRS to execute normal power-on/power-off reset.

Absolute maximum rating:

Input voltage(V_CC)  4~6V        Operating temperature range(T_C) --55~+200℃

Storage temperature                 --65~+200℃                       Lead soldering temperature resistance(10S) -300℃

Package type- adoptingBB483-08, dimensions see Appendix Figure.12.。

• HJ42131A
• HJ42131B
• TMS320F2812
• F2810
• 上电/掉电
• 复位功能
• 高温三路低压差稳压源