Supplying over 100mA of current through two adjustable power rails

Linear Technology Korea (CEO Hong Sa-kwak) announced the launch of a new 6-channel SPI/Digital or I2C μModule® isolator (product name: LTM2887) that provides stable dual-rail power for low-voltage devices, including the latest DSPs and microprocessors.

The two isolated outputs are adjustable (up to 5V) and deliver load currents of over 100mA with an efficiency of up to 62%. The voltage can be lowered to approximately 0.6V for the auxiliary input, and the isolated logic input power supply can be lowered to 1.8V for the SPI interface. Each output is provided with a precise current limiting pin, and voltage can be adjusted using an external resistor.

In industrial system applications, ground potential varies significantly; it often exceeds limiting factors, causing communication interference or, in severe cases, damaging components. The LTM2887 breaks ground loops by electrically isolating logic-level interfaces on each side of internal isolation barriers. These inductively coupled barriers withstand very high ground differential voltages of up to 2,500 VRMS.

An isolated DC/DC converter with low EMI powers the LTM2887 and provides isolated power to the communication interface and output rails. Direct interface connection to a low-voltage microcontroller (MCU) as low as 1.62V is possible via a separate logic input power pin, and current consumption can be reduced to 10μA or less by shutting down the LTM2887 via the ON pin. The LTM2887 supports uninterrupted communication for common-mode transient response characteristics of over 30kV/μs and provides robust ±10kV ESD (HBM) protection across an insulation barrier.

The LTM2887 is available in two versions depending on the supported communication interface. The LTM2887-I is compatible with I2C interfaces up to 400 kHz and supports bidirectional serial data (SDA) and clock (SCL), as well as three additional isolated CMOS logic signals operating up to 10 MHz. The LTM2887-S is an SPI-compatible product that provides a total of six isolated CMOS digital communication channels. All channels operate up to 10 MHz and include three forward signals (CS, SCK, SDI) and three reverse signals (SDO, DO1, DO2). When configured for SPI communication, the maximum clock speed is 8 MHz for unidirectional communication and 4 MHz for round-trip bidirectional operation.

The LTM2887 is available in 3.3V or 5V input voltage versions and in a 15mm x 11.25mm surface-mount BGA package. All ICs and passive components are integrated into a RoHS-compliant μModule package. The LTM2887 is available in commercial, industrial, and automotive versions, with operating temperature ranges of 0°C to 70°C, –40°C to 85°C, and –40°C to 105°C, respectively.