Output drive and what it means for the load
The SN74LS157D sources 400 µA and sinks 8 mA per output. That sink capability is enough to drive a standard TTL input or a low-power LED indicator directly, but it will not handle a relay coil or a bus transceiver without a buffer. If the downstream load demands more than 8 mA per channel, plan on a line driver or a higher-drive logic family.
Lifecycle and sourcing reality
Listed as Active with ROHS3 compliance.
