The SN75LV4737A is the latest in TI's line of charge-pump RS-232 devices with three drivers and five receivers which provide a single-chip interface for an IBM PC/AT serial port. The SN75LV4737A is designed to be fully compliant with ANSI EIA/TIA-232-E standards. The '4737A provides advanced power management, the latest charge-pump technology, and supports data rates up to 120 kbps over a three meter cable.
The SN75LV4737A operates from a single 3.3- or 5-V supply, and accepts 5 V logic inputs even when operating from a 3.3-V supply. The charge-pump requires just four small 0.1 µF capacitors with a 5-V supply, or five capacitors with a 3.3V supply. It is well suited for notebooks, palmtops, terminals, modems, and many other battery operated applications.
The '4737A decreases parts count, reduces board space requirements, and allows easy interconnection. The pin-out matches the design of its predecessor, the SN75LV4735, and is a drop-in replacement for the National Semiconductor DS14C335 (3.3 V) and DS14C535 (5 V) devices, thereby reducing the number of device types in inventory by 50%.
As power management and power conservation become bigger issues to the PC designer, parts such as the SN75LV4737A become required equipment. The 'LV4737A has two power-down modes to extend battery life. The standby mode disables the entire device with a low current requirement of only 5 µA. The wake-up mode allows one receiver to remain active during shut-down to enable the part when data is received, thus minimizing the risk of losing incoming data. In wake-up mode, the current consumption is only 10 µA, which is very close to the leakage current of most batteries.
The SN75LV4737A is made from our LinBiCMOS process and is available in a 28-pin Shrink-Small-Outline-Package (DBLE).
Vol 11, Spring, 1995