RS485 – STEP UP POWER

RS-485 SN75HVD08

The SN75HVD08 combines a 3-state differential line driver and differential line receiver designed for balanced data transmission and interoperation with ANSI TIA/EIA-485-A and ISO-8482E standard-compliant devices.
The wide supply voltage range and low quiescent current requirements allow the SN75HVD08s to operate from a 5-V power bus in the cable with as much as a 2-V line voltage drop. Busing power in the cable can alleviate the need for isolated power to be generated at each connection of a ground-isolated bus.
The driver differential outputs and receiver differential inputs connect internally to form a differential input/output (I/O) bus port that is designed to offer minimum loading to the bus whenever the driver is disabled or not powered. The drivers and receivers have active-high and active-low enables respectively, which can be externally connected together to function as a direction control.

Features RS-485 SN75HVD08:

• Operates With a 3-V to 5.5-V Supply
• Consumes Less Than 90-mW Quiescent Power
• Open-Circuit, Short-Circuit, and Idle-Bus Failsafe Receiver
• 1/8th Unit-Load (up to 256 nodes on the bus)
• Bus-Pin ESD Protection Exceeds 16-kV HBM
• Driver Output Voltage Slew-Rate Limited for Optimum Signal Quality at 10 Mbps
• Electrically Compatible With ANSI TIA/EIA-485 Standard

STEP-UP SC4503

The SC4503 is a 1.3MHz current-mode step-up switching regulator with an integrated 1.4A power transistor.
Its high switching frequency allows the use of tiny surface-mount external passive components. The SC4503 features a combined shutdown and soft-start pin. The optional soft-start function eliminates high input current
and output overshoot during start-up. The internal compensation network accommodates a wide range of voltage conversion ratios.
The internal switch is rated at 34V making the device suitable for high voltage applications such as Boost and SEPIC.

The pcb connections are compatible with «EXPANSION BOARD ESP32 ARUAL» and «BOARD ARDUINO ATMEGA328P – PEREGRINO 2».

Features SC4503:

• Low Saturation Voltage Switch: 260mV at 1.4A
• 1.3MHz Constant Switching Frequency
• Peak Current-mode Control
• Internal Compensation
• Programmable Soft-Start
• Input Voltage Range From 2.5V to 20V
• Output Voltage up to 27V
• Uses Small Inductors and Ceramic Capacitors
• Low Shutdown Current (< 1μA)