NXP Semiconductors 74ALVCHS162830DGB:

Overview

74ALVCHS162830DGB from NXP Semiconductors (formerly Philips) is an 18-bit to 36-bit address driver with bus hold and 3-state outputs, designed for SDRAM module applications operating at 2.3 V–3.6 V supply. It features ±12 mA balanced output drive, integrated 26 Ω series resistors per output, bus-hold on all 18 inputs, and operates across –40 °C to +85 °C.

For engineers reviewing the 74ALVCHS162830DGB datasheet, 74ALVCHS162830DGB pinout, 74ALVCHS162830DGB application, or 74ALVCHS162830DGB equivalent, key selection criteria include bus-hold current (±75 µA at 3 V), low-noise 3-state timing (tpd ≤ 3.5 ns at 3.3 V), thermal impedance (106 °C/W), and TVSOP-80 package compatibility with PCK953-based memory modules.

Technical Context

This device implements dual 3-state enable logic (OE1/OE2) controlling two independent 18-channel output banks (1Yn/2Yn), each driven by a dedicated 18-bit input bus (An). Bus-hold circuitry actively retains the last valid logic state on each An input when the bus floats, eliminating external biasing components.

Each output integrates a 26 Ω series resistor to dampen signal reflections and reduce overshoot/undershoot without requiring external termination. The design supports high-speed address propagation in SDRAM systems with low skew (<500 ps) and tight propagation delay matching across all 36 outputs.

Key Specifications

Pinout & Package

Package: 80-pin plastic thin very small-outline package (TVSOP), body width 6.1 mm, pitch 0.4 mm (SOT647-1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar address driver applications.

Compared with 74ALVCHS162830DGB, the 74ALVCH162830DGGR omits bus-hold and increases BOM complexity, while SN74ALVCH162830GR offers better thermal performance but requires validation of TI-specific qualification documentation for regulated industries.

Availability

74ALVCHS162830DGB is available at Aetrix Electronics and suitable for SDRAM module manufacturing, industrial memory controller integration, and telecom baseband subsystems requiring stable component supply and long-term lifecycle support.

Supply support for 74ALVCHS162830DGB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors, formerly Philips Semiconductors, is a global leader in high-performance analog and logic ICs for automotive, industrial, and communications infrastructure.

The 74ALVCHS162830DGB belongs to the ALVCHS advanced low-voltage CMOS logic family, engineered specifically for high-speed, low-noise memory interface applications in SDRAM modules and embedded controllers.

FAQ

What is the primary function of the 74ALVCHS162830DGB in memory systems?

The 74ALVCHS162830DGB serves as an 18-bit-to-36-bit address driver with bus-hold and 3-state outputs, enabling reliable fanout from a memory controller to multiple SDRAM chips. Its integrated 26 Ω series resistors and ±12 mA drive capability allow it to directly drive address lines without external termination, and its bus-hold feature maintains valid logic states during bus idle periods - a key requirement in SDRAM module designs using the 74ALVCHS162830DGB.

Does the 74ALVCHS162830DGB require external pull-up or pull-down resistors on its inputs?

No, the 74ALVCHS162830DGB does not require external pull-up or pull-down resistors because it includes bus-hold circuitry on all 18 An inputs. This internal feature actively retains the last valid logic state when the input bus goes high-impedance, preventing floating nodes. Confirmed by the datasheet's "Bus hold on data inputs eliminates the need for external pullup/pulldown resistors" statement and measured bus-hold current of ±75 µA at 3 V - a core specification of the 74ALVCHS162830DGB.

What package type and footprint does the 74ALVCHS162830DGB use?

The 74ALVCHS162830DGB uses an 80-pin plastic thin very small-outline package (TVSOP) with 0.4 mm pitch and 6.1 mm body width, designated SOT647-1. This package is distinct from standard TSSOP variants due to thinner profile and tighter pitch, enabling higher density in memory module layouts. The pin configuration is fully documented in the datasheet's PIN CONFIGURATION diagram and matches the physical layout of the 74ALVCHS162830DGB device.

How does the 74ALVCHS162830DGB manage signal integrity on its 36 outputs?

The 74ALVCHS162830DGB manages signal integrity through integrated 26 Ω series resistors on each of its 36 outputs, which dampen ringing and reduce overshoot/undershoot without external components. It also achieves <500 ps output skew and ≤3.5 ns propagation delay at 3.3 V, ensuring synchronized address delivery. Input clamp diodes and ±2000 V HBM ESD protection further enhance robustness - all verified electrical characteristics of the 74ALVCHS162830DGB.

What is the recommended power-up sequence for the 74ALVCHS162830DGB to ensure safe 3-state behavior?

To ensure the 74ALVCHS162830DGB outputs remain in high-impedance during power-up or power-down, OE1 and OE2 must be held high via pull-up resistors tied to VCC. The datasheet specifies that the minimum pull-up resistor value depends on the driver's current-sinking capability - typically ≥10 kΩ for most implementations. This requirement prevents bus contention at power transition boundaries and is a mandatory design rule for reliable operation of the 74ALVCHS162830DGB.