“This white paper discusses digital optocouplers for low power, low supply voltage applications. This article also introduces the Avago ACPL-x2xL digital optocouplers with CMOS outputs. Digital optocouplers in electrical systems provide high voltage isolation and noise suppression for data transmission.
This white paper discusses digital optocouplers for low power, low supply voltage applications. This article also introduces the Avago ACPL-x2xL digital optocouplers with CMOS outputs. Digital optocouplers in electrical systems provide high voltage isolation and noise suppression for data transmission.
Digital optocouplers in electrical systems provide high voltage isolation and noise suppression for data transmission. A high-quality insulating barrier is required in optocouplers to provide excellent reliability and durability for signal isolation.
In addition to isolation and noise suppression features, Avago’s new 5 MBd digital optocouplers ACPLM21L/021L/024L/W21L/K24L, ACPL-x2xL series offer significant power savings and efficiency improvements for power-saving applications. Now, for many Electronic applications such as industrial, medical, power control systems, communications, etc., there is a requirement to reduce system power consumption. These new digital optocouplers consume 80% less power than conventional 5 MBd digital optocouplers on the market.
Key Features and Specifications
The ACPL-x2xL digital optocouplers are newly designed optocouplers with CMOS output to reduce power consumption. They are designed for a variety of applications such as computer peripheral device interfaces, microprocessor system interfaces, high-speed line receivers, power control systems, and more. Device performance is guaranteed over a wide temperature range of C40 to 105°C, making it ideal for industrial applications.
The main features of the ACPL-x2xL digital optocoupler series are as follows:
Low LED input current allows direct drive from CMOS output without external buffers (see Figure 1)
Low supply current and supply voltage, low power consumption
25 kV/µs static common mode rejection C does not reduce immunity
Schmitt trigger input for better noise immunity
IEC60747-5-5 reinforced insulation certified, ACPL-M21L/021L/024L has a continuous working voltage of 567 Vpeak and a transient voltage of 6 kVpeak, and ACPL-W21L/K24L has a continuous working voltage of 1140 Vpeak and a transient voltage of 8 kVpeak
ACPL-M21L is directly driven by MCU/FPGA/DSP without external buffers
Low power consumption
The advantage of the new 5 MBd digital optocoupler series is low power consumption. The new ACPL-x2xL series optocouplers consume less than 10mW without compromising signal isolation capabilities. Compared to conventional 5 MBd digital optocouplers and others, the new 5 MBd digital optocouplers feature a minimum input drive current of 1.6 mA, a maximum supply current of 1.1 mA, and a low supply voltage of 3.3 V, reducing power consumption as much as 80%. isolators on the market.
Figure 2 shows the new 5MBd digital optocoupler with the lowest power consumption among other 5MBd digital optocouplers on the market.
Power consumption comparison: ACPL-x2xL vs conventional 5MBd optocouplers on the market
Better performance and improved functionality
The new ACPL-x2xL optocoupler family offers higher performance and improved functionality compared to the HCPL-x2xx traditional optocouplers in low voltage logic applications (see Table 1). The upgraded ACPLx2xL series optocouplers feature features such as low supply current, low LED input current, low supply voltage, higher CMR and wider temperature range. The new 5 MBd digital optocouplers can be used in low voltage logic applications (2.5 V/3.3 V/5 V supply voltage).
Table 1. Comparison of ACPL-x2xL and HCPL-x2xx
Optocoupler CMR Performance
Common mode noise can be an important issue in data communication applications, especially in industrial environments where motors, sensors and programmable logic controllers are connected together.
An internal proprietary Faraday shield is an effective planar metal trace around the output receiver, providing ESD protection and decoupling the input and output sides of the optocoupler. This unique package design also minimizes input-to-output capacitance. These two factors minimize the effect of common-mode noise, resulting in high common-mode transient immunity of >25 kV/us @Vcm = 1000 V.
The “shunt resistor” input LED driver configuration balances the impedance between the LED anode and cathode, further improving CMR performance. The common mode noise voltage rise on the LED is symmetrical, so the LED cannot be turned on. The series-connected LED and current-limiting resistor form a low-pass filter that helps filter out noise transients.