The SN74GTLPH1645 is a high-drive, 16-bit bus transceiver that provides LVTTL-to-GTLP and GTLP-to-LVTTL signal-level translation. It is partitioned as two 8-bit transceivers. The device provides a high-speed interface between cards operating at LVTTL logic levels and a backplane operating at GTLP signal levels. High-speed (about three times faster than standard LVTTL or TTL) backplane operation is a direct result of GTLP's reduced output swing (<1 V), reduced input threshold levels, improved differential input, OEC™ circuitry, and TI-OPC™ circuitry. Improved GTLP OEC and TI-OPC circuits minimize bus-settling time and have been designed and tested using several backplane models. The high drive allows incident-wave switching in heavily loaded backplanes with equivalent load impedance down to 11 .

GTLP is the Texas Instruments derivative of the Gunning Transceiver Logic (GTL) JEDEC standard JESD 8-3. The ac specification of the SN74GTLPH1645 is given only at the preferred higher noise-margin GTLP, but the user has the flexibility of using this device at either GTL (VTT = 1.2 V and VREF = 0.8 V) or GTLP (VTT = 1.5 V and VREF = 1 V) signal levels.

Normally, the B port operates at GTLP signal levels. The A-port and control inputs operate at LVTTL logic levels but are 5-V tolerant and are compatible with TTL and 5-V CMOS inputs. VREF is the B-port differential input reference voltage.

This device is fully specified for live-insertion applications using Ioff, power-up 3-state, and BIAS VCC. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down. The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down, which prevents driver conflict. The BIAS VCC circuitry precharges and preconditions the B-port input/output connections, preventing disturbance of active data on the backplane during card insertion or removal, and permits true live-insertion capability.

This GTLP device features TI-OPC circuitry, which actively limits the overshoot caused by improperly terminated backplanes, unevenly distributed cards, or empty slots during low-to-high signal transitions. This improves signal integrity, which allows adequate noise margin to be maintained at higher frequencies.

High-drive GTLP backplane interface devices feature adjustable edge-rate control (ERC\). Changing the ERC\ input voltage between GND and VCC adjusts the B-port output rise and fall times.This allows the designer to optimize system data-transfer rate and signal integrity to the backplane load.

Active bus-hold circuitry holds unused or undriven LVTTL data inputs at a valid logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.

When VCC is between 0 and 1.5 V, the device is in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 1.5 V, the output-enable (OE\) input should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

• Member of the Texas Instruments Widebus™ Family
• TI-OPC™ Circuitry Limits Ringing on Unevenly Loaded Backplanes
• OEC™ Circuitry Improves Signal Integrity and Reduces Electromagnetic Interference
• Bidirectional Interface Between GTLP Signal Levels and LVTTL Logic Levels
• LVTTL Interfaces Are 5-V Tolerant
• High-Drive GTLP Outputs (100 mA)
• LVTTL Outputs (\x9624 mA/24 mA)
• Variable Edge-Rate Control (ERC\) Input Selects GTLP Rise and Fall Times for Optimal Data-Transfer Rate and Signal Integrity in Distributed Loads
• Ioff, Power-Up 3-State, and BIAS VCC Support Live Insertion
• Bus Hold on A-Port Data Inputs
• Distributed VCC and GND Pins Minimize High-Speed Switching Noise
• Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II

OEC, TI-OPC, and Widebus are trademarks of Texas Instruments.

• SN10KHT5541 - 具有三态输出的八路 ECL 至 TTL 转换器
• LM26LV - 具有固定跳变点且支持 1.6V 电压的温度开关
• TPS77818 - 单输出 LDO、750mA、固定电压 (1.8V)、快速瞬态响应、电源良好 (PG) 输出
• BQ24205 - 采用 MSOP-8 封装用于限流应用的 500mA 4.1V 单片锂离子充电器，
• TMS320C6416 - 定点数字信号处理器
• PTV05010W - 具有自动跟踪功能的 8A 5V 输入非隔离宽输出调节 SIP 模块
• DS90UH947-Q1 - DS90UH947-Q1 1080p 双路 FPD-Link III 串行器
• SN74LS273 - 具有清零功能的八路 D 类触发器
• LM4550B - AC '97 Rev 2.1 Codec with Sample Rate Conversion and National 3D Sound
• CD54HCT259 - 高速 CMOS 逻辑 8 位可寻址锁存器