xr XR16L2750 2.25V TO 5.5V DUART WITH 64-BYTE FIFO APRIL 2005 REV. 1.2.1 FEATURES GENERAL DESCRIPTION 2.25 to 5.5 Volt Operation 1 The XR16L2750 (2750) is a low voltage dual 5 Volt Tolerant Inputs universal asynchronous receiver and transmitter (UART) with 5 Volt tolerant inputs. The device Pin-to-pin compatible to Exars ST16C2550 and operates from 2.25 to 5.5 Volt supply range and is TIs TL16C752B on the 48-TQFP package pin-to-pin compatible to Exars ST16C2550 and Pin alike XR16C2850 48-TQFP package but XR16C2850 except the 48-TQFP package. The 2750 without CLK8/16, CLKSEL and HDCNTL inputs register set is compatible to the ST16C2550 and the Two independent UART channels XR16C2850 enhanced features. It supports the Exars enhanced features of 64 bytes of TX and RX Reg set compatible to 16C2550 and 16C2850 FIFOs, programmable FIFO trigger level and FIFO Up to 6.25 Mbps at 5 Volt, 4 Mbps at 3.3 Volt, level counters, automatic hardware (RTS/CTS) and and 3 Mbps at 2.5 Volt with 8X sampling rate software flow control, automatic RS-485 half duplex Transmit and Receive FIFOs of 64 bytes direction control output and a complete modem Programmable TX and RX FIFO Trigger Levels interface. Onboard registers provide the user with Transmit and Receive FIFO Level Counters operational status and data error flags. An internal Automatic Hardware (RTS/CTS) Flow Control loopback capability allows system diagnostics. Independent programmable baud rate generators are Selectable Auto RTS Flow Control Hysteresis provided in each channel to select data rates up to Automatic Software (Xon/Xoff) Flow Control 6.25 Mbps at 5 Volt and 8X sampling clock. The 2750 Automatic RS-485 Half-duplex Direction is available in 48-pin TQFP and 44-pin PLCC Control Output via RTS packages. Wireless Infrared (IrDA 1.0) Encoder/Decoder NOTE: 1 Covered by U.S. Patent 5,649,122 and 5,949,787 Automatic sleep mode APPLICATIONS Full modem interface Device Identification and Revision Portable Appliances Crystal oscillator or external clock input Telecommunication Network Routers Industrial and commercial temperature ranges Ethernet Network Routers 48-TQFP and 44-PLCC packages Cellular Data Devices Factory Automation and Process Controls FIGURE 1. XR16L2750 BLOCK DIAGRAM * 5 Volt Tolerant Inputs 2.25 to 5.5 Volt VCC A2:A0 (Except XTAL1) GND D7:D0 IOR UART Channel A IOW TXA, RXA, DTRA , 64 Byte TX FIFO CSA UART DSRA , RTSA , Regs DTSA , CDA , RIA , CSB IR TX & RX ENDEC OP2A 8-bit Data INTA BRG Bus 64 Byte RX FIFO INTB Interface TXRDYA TXB, RXB, DTRB , TXRDYB UART Channel B DSRB , RTSB , RXRDYA (same as Channel A) CTSB , CDB , RIB , RXRDYB OP2B Reset XTAL1 Crystal Osc/Buffer XTAL2 2750BLK Exar Corporation 48720 Kato Road, Fremont CA, 94538 (510) 668-7000 FAX (510) 668-7017 www.exar.com XR16L2750 xr 2.25V TO 5.5V DUART WITH 64-BYTE FIFO REV. 1.2.1 FIGURE 2. PIN OUT ASSIGNMENT 1 36 RESET D5 D6 2 35 DTRB D7 3 34 DTRA RTSA RXB 4 33 RXA 5 32 OP2A XR16L2750 TXRDYB 6 31 RXRDYA 48-pin TQFP TXA 7 30 INTA TXB 8 29 INTB A0 OP2B 9 28 CSA 10 27 A1 11 26 A2 CSB NC 12 25 NC D5 7 39 RESET D6 8 38 DTRB D7 9 37 DTRA RXB 10 36 RTSA 11 35 OP2A RXA XR16L2750 TXRDYB 12 34 RXRDYA 44-pin PLCC TXA 13 33 INTA TXB 14 32 INTB OP2B 15 31 A0 CSA 16 30 A1 17 29 A2 CSB ORDERING INFORMATION PART NUMBER PACKAGE OPERATING TEMPERATURE RANGE DEVICE STATUS XR16L2750CJ 44-Lead PLCC 0C to +70C Active XR16L2750IJ 44-Lead PLCC -40C to +85C Active XR16L2750CM 48-Lead TQFP 0C to +70C Active XR16L2750IM 48-Lead TQFP -40C to +85C Active 2 XTAL1 48 13 D4 18 XTAL1 6 D4 XTAL2 14 47 D3 XTAL2 19 5 D3 IOW 15 46 D2 20 IOW 4 D2 CDB 16 45 D1 CDB 21 3 D1 GND 17 44 D0 22 RXRDYB 43 TXRDYA GND 2 D0 18 IOR 19 42 VCC RXRDYB 23 1 TXRDYA DSRB 20 41 RIA IOR 24 44 VCC RIB 21 40 CDA DSRB 25 43 RIA RTSB 39 22 DSRA RIB 26 42 CDA CTSB 38 CTSA 23 RTSB 27 41 DSRA NC 24 37 NC CTSB 28 40 CTSA