GTL2018PW - 8-Bit LVTTL to GTL Transceiver | NXP | TSSOP-24
MPN: GTL2018PW ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.65 | $26.50 |
| 100 | $2.3 | $230.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.85 | $1,850.00 |
GTL2018PW Overview
A GTL (Gunning Transceiver Logic) translator is a type of mixed-signal voltage level translator in the broader family of bus transceivers and logic level shifters. GTL buses use an open-drain, low-swing signaling scheme referenced to a termination voltage, which historically allowed high-speed backplanes and memory interfaces to run with low electromagnetic emissions. Level translators like the GTL2018 form the bridge between a processor or ASIC-side LVTTL/CMOS logic domain and the low-voltage-swing GTL domain, sitting in the system hierarchy between simple logic gates and full bus repeater or register functions.
Key features of the GTL2018 include its octal (8-channel) configuration for wide data buses, bidirectional operation controlled by the DIR pin so one device can serve as either a GTL-to-LVTTL sampling receiver or an LVTTL-to-GTL driver, and LVTTL-side input tolerance up to 5.5 V, which permits direct connection to TTL or 5 V CMOS signal sources without external protection. This 5 V tolerance is a practical advantage in mixed-legacy designs where older 5 V logic must interface with a GTL bus.
Technically, the GTL side operates with an open-drain output structure pulled to the GTL reference level (typically VTT around 1.2 V to 1.5 V depending on the GTL, GTL-, or GTL+ variant used), while the LVTTL side runs from a 3.3 V supply per the specification data. The device operates across an industrial temperature range of -40C to +85C, making it suitable for telecommunication and computing infrastructure equipment.
Typical applications include processor-to-backplane data buses in networking and telecom equipment, memory interface translation in legacy server and workstation designs, and mixed-voltage interface cards where 3.3 V or 5 V TTL logic must communicate over a GTL/GTL+ bus.
Design considerations: always provide a low-impedance termination to VTT on the GTL side, since the open-drain outputs do not actively drive high; the pull-up termination sets the bus high level and termination current.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, with pricing verified as of 2026-10-19.
Drop-in alternatives for GTL2018PW — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with GTL2018PW (same form factor and footprint) — differing in Direction Control, Function, LVTTL Input Tolerance, Package Type, Automotive Variant.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
GTL2018PW,112
✅ Drop-In📋 Reference alternative (not in catalog)
GTL2018PW/Q900
✅ Drop-In📋 Reference alternative (not in catalog)
GTL2018PW Specifications
| Function | 8-bit bidirectional LVTTL to GTL/GTL-/GTL+ translating transceiver |
| Number of Channels | 8 |
| Direction Control | DIR pin (GTL-to-LVTTL receive or LVTTL-to-GTL drive) |
| LVTTL Side Supply Voltage | 3.3 V |
| LVTTL Input Tolerance | 5.5 V (TTL and 5 V CMOS compatible inputs) |
| GTL Side Output Type | Open-drain (requires VTT termination) |
| GTL Bus Compatibility | GTL, GTL-, GTL+ |
| Operating Temperature Range | -40C to +85C |
| Package Type | TSSOP-24 (SOT355-1), 4.40 mm body |
| Pin Count | 24 |
| Mounting Type | Surface Mount |
| Packaging Option | GTL2018PW,112 (bulk); GTL2018PW,118 (tape and reel) |
| Automotive Variant | GTL2018PW/Q900 available (AEC qualified variant per NXP ordering codes) |
GTL2018PW Pin Configuration
| Pin 1 | OE — [DATA_NEEDED: pin function per datasheet] |
| Pin 2 | D0 (LVTTL) — [DATA_NEEDED: pin function per datasheet] |
| Pin 3 | D1 (LVTTL) — [DATA_NEEDED: pin function per datasheet] |
| Pin 4 | D2 (LVTTL) — [DATA_NEEDED: pin function per datasheet] |
| Pin 5 | D3 (LVTTL) — [DATA_NEEDED: pin function per datasheet] |
| Pin 6 | GND — [DATA_NEEDED: pin function per datasheet] |
| Pin 7 | D4 (LVTTL) — [DATA_NEEDED: pin function per datasheet] |
| Pin 8 | D5 (LVTTL) — [DATA_NEEDED: pin function per datasheet] |
| Pin 9 | D6 (LVTTL) — [DATA_NEEDED: pin function per datasheet] |
| Pin 10 | D7 (LVTTL) — [DATA_NEEDED: pin function per datasheet] |
| Pin 11 | DIR — [DATA_NEEDED: pin function per datasheet] |
| Pin 12 | GND — [DATA_NEEDED: pin function per datasheet] |
| Pin 13 | GTL7 — [DATA_NEEDED: pin function per datasheet] |
| Pin 14 | GTL6 — [DATA_NEEDED: pin function per datasheet] |
| Pin 15 | GTL5 — [DATA_NEEDED: pin function per datasheet] |
| Pin 16 | GTL4 — [DATA_NEEDED: pin function per datasheet] |
| Pin 17 | VDD (LVTTL 3.3 V) — [DATA_NEEDED: pin function per datasheet] |
| Pin 18 | GTL3 — [DATA_NEEDED: pin function per datasheet] |
| Pin 19 | GTL2 — [DATA_NEEDED: pin function per datasheet] |
| Pin 20 | GTL1 — [DATA_NEEDED: pin function per datasheet] |
| Pin 21 | GTL0 — [DATA_NEEDED: pin function per datasheet] |
| Pin 22 | VTT / GND — [DATA_NEEDED: pin function per datasheet] |
| Pin 23 | VDD (LVTTL 3.3 V) — [DATA_NEEDED: pin function per datasheet] |
| Pin 24 | OE/NC — [DATA_NEEDED: pin function per datasheet] |
Typical Applications
GTL2018PW is suitable for 6 applications: Processor-to-Backplane GTL Bus Interface, Telecom Line Card Level Translation, Legacy Memory Interface Translation, Mixed-Voltage Interface Cards, Networking Equipment Data Path Translation, Test and Measurement Adapter Fixtures.
Processor-to-Backplane GTL Bus Interface
The GTL2018PW's core application is bridging a 3.3 V LVTTL processor or ASIC data bus to an open-drain GTL/GTL+/GTL- backplane. Its eight bidirectional channels map directly onto an 8-bit data slice, and the DIR pin allows a single device to switch between driving the GTL bus from LVTTL logic and receiving GTL signals back into the LVTTL domain as a sampling receiver. Because the GTL-side outputs are open-drain, the backplane termination to VTT sets the high level, keeping bus switching currents low and emissions controlled. The 5.5 V tolerant LVTTL inputs additionally allow direct connection to legacy 5 V TTL control signals on the card, simplifying mixed-generation board designs.
Recommended
Telecom Line Card Level Translation
Telecom central-office line cards frequently mix 3.3 V LVTTL control logic, legacy 5 V TTL signals, and low-swing GTL interconnect to a backplane or framer. The GTL2018PW fits this role because its LVTTL inputs tolerate up to 5.5 V, permitting direct hookup of 5 V CMOS/TTL sources without protection networks, while its GTL side speaks GTL, GTL-, or GTL+ depending on the bus standard used. The industrial -40C to +85C temperature range covers central-office ambient requirements. Designers should budget termination power on the GTL side and keep the VTT supply low-impedance, since open-drain bus pull-up current flows continuously whenever the bus is held low.
Recommended
Legacy Memory Interface Translation
Older server and workstation memory subsystems used GTL-class signaling between the memory controller and DIMM connectors. When servicing or extending such designs, the GTL2018PW provides the required 8-channel LVTTL-to-GTL translation with sampling-receiver mode for read paths and driver mode for write paths, selected by the DIR pin. The 3.3 V LVTTL side connects to modern controller logic, while the open-drain GTL side interfaces the terminated memory bus through VTT pull-ups. Because GTL levels vary slightly among GTL, GTL-, and GTL+ standards, confirm the VTT reference of the specific memory bus before finalizing termination resistor values in the layout.
Recommended
Mixed-Voltage Interface Cards
Industrial and communications interface cards often must connect 5 V TTL peripherals, 3.3 V microcontroller logic, and a low-voltage GTL bus within one assembly. The GTL2018PW addresses two of the three domains simultaneously: its 5.5 V tolerant LVTTL inputs accept legacy TTL directly, and its GTL side terminates to the GTL bus reference. The DIR pin gives firmware or hardware control over data direction per transfer, supporting half-duplex bus protocols. Engineers should verify that the 3.3 V LVTTL supply is well decoupled, and treat the GTL side as an analog-like node in layout, keeping stub lengths short to preserve the low-swing signal integrity the GTL standard was designed to provide.
Recommended
Networking Equipment Data Path Translation
Routers and switches built around GTL-class backplanes use translators such as the GTL2018PW between the switching silicon's LVTTL-side control/data pins and the open-drain GTL fabric. Eight channels per device allow scaling to wider buses by paralleling multiple GTL2018PW devices, with DIR common-driven so all channels change direction together - matching typical half-duplex bus transactions. The device's ability to accept 5 V CMOS inputs simplifies interfacing to older management-plane logic. For high channel-count designs, distribute VTT termination resistors close to each GTL pin and provide a solid, low-inductance VTT plane to keep bus reflections within the small GTL noise margins.
Recommended
Test and Measurement Adapter Fixtures
Bench fixtures that probe or emulate GTL buses benefit from the GTL2018PW because it cleanly separates the instrument's 3.3 V or 5 V TTL domain from the device-under-test's terminated GTL lines. In receive mode the part samples GTL levels into LVTTL for logic analyzers; in drive mode it emulates a GTL driver under MCU control via the DIR pin. Its TSSOP-24 footprint suits small adapter boards, and the -40C to +85C range tolerates typical lab environments. Fixture designers should add series resistors on the LVTTL side for protection during hot-plug events and ensure the fixture's VTT supply can sink the termination current of all eight channels simultaneously.
Recommended
Recommended Products Summary
Engineering reference data for GTL2018PW — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | GTL2018PW,112 | GTL2018PW/Q900 |
|---|---|---|---|
| Package | TSSOP-24 (SOT355-1) | TSSOP-24 (SOT355-1) - same package, bulk packing | TSSOP-24 (SOT355-1) - same package |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Channels | 8 bidirectional | 8 bidirectional | 8 bidirectional |
| LVTTL Supply | 3.3 V | 3.3 V | 3.3 V |
| LVTTL Input Tolerance | 5.5 V | 5.5 V | 5.5 V |
| GTL Bus Standards | GTL / GTL- / GTL+ | GTL / GTL- / GTL+ | GTL / GTL- / GTL+ |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C (per NXP ordering data) |
| Quality Flow / Packing | Standard flow, tape & reel (,118) | Standard flow, bulk packing | Q900 quality flow variant |
| Direction Control | DIR pin | DIR pin | DIR pin |
Key Differentiators
- 5.5 V tolerant LVTTL inputs eliminate external protection (vs GTL2018PW/Q900 (identical electrical spec))
- Three GTL bus standards supported in one device (vs Fixed-standard translators)
- Q900 quality-flow option for high-reliability programs (vs GTL2018PW,112 (standard flow))
Design Notes
Terminate the GTL bus to VTT close to the GTL2018PW pins or at the bus end per your topology. Because the GTL-side outputs are open-drain, all high-level drive comes from the VTT pull-ups; a missing or high-impedance termination leaves the bus floating and invalidates the receiver thresholds. Keep GTL traces short and stub-free, referencing them to a solid ground plane, since the GTL noise margin is small by design.
Estimated: termination power can dominate the GTL-side budget. For example, with VTT = 1.5 V and 50 ohm pull-ups, each channel held low sinks roughly 30 mA, so an 8-channel bus held low dissipates about 0.36 W in the terminations alone - size the VTT supply accordingly. The LVTTL 3.3 V supply should be decoupled with at least 0.1 uF per supply pin placed within 2-3 mm of the TSSOP-24 package.
Do not drive the LVTTL side from push-pull sources exceeding 5.5 V - the tolerance limit is absolute even though standard TTL is 5 V. Also ensure DIR is never left floating during power-up: an undefined direction state can produce bus contention on the GTL lines. Tie DIR through a pull-up or pull-down resistor to a defined state and only change it when the bus is idle, as recommended in NXP's general GTL application guidance.
Compliance Information
Compliance data was not present in the provided verified web data. The /Q900 ordering option indicates an upgraded NXP quality flow but is not an AEC-Q100 qualification statement. Verify RoHS/REACH status on the official NXP product page before procurement.
