SPI/Digital or I²C micromodule isolator with dual adjustable 5V regulators
Two well-regulated adjustable supply rails (up to 5V) deliver more than 100 mA of load current over the isolation barrier, with up to 62% efficiency. The voltages may be adjusted (using a single external resistor) as low as 0.6V for the auxiliary supply, while the isolated logic supply may be as low as 1.8V for SPI interfaces. Each supply provides a precise current limit adjustment pin and the ability to adjust the voltage using external resistors. The logic supply pin allows interfacing with different logic levels from 1.62V to 5.5V, independent of the main supply.
Coupled inductors and an isolation power transformer provide 2500VRMS of isolation between the input and output logic interface. This device is suitable for systems where the ground loop is broken, allowing for a large common mode voltage range. Communication is uninterrupted for common mode transients greater than 30 kV/μsec.
Linear Technology; www.linear.com/product/LTM2887
next page; feature listing…
6-channel logic isolator: 2500 VRMS for 1 minute
UL-CSA recognition pending
Isolated DC power:
1.8V to 5V logic supply at up to 100 mA
0.6V to 5V auxiliary supply at up to 100 mA
No external components required
SPI/Digital (LTM2887-S) or I²C (LTM2887-I) options
High common mode transient immunity: 30 kV/μsec
High speed operation:
10 MHz digital isolation
4 MHz/8 MHz SPI isolation
400 kHz I²C isolation
3.3V (LTM2887-3) or 5V (LTM2887-5) operation
1.62V to 5.5V logic supply
±10 kV ESD HBM across the isolation barrier
Maximum continuous working voltage: 560 VPEAK
Low current shutdown mode (<10 μA)
Low profile 15 × 11.25 × 3.42 mm BGA package
