NXP Semiconductors MC88916DW70

Overview

MC88916DW70 from Freescale Semiconductor (formerly Motorola) is a low-skew CMOS PLL clock driver designed for CISC and single-processor RISC systems, specifically supporting the MC68030/040 microprocessor families. It delivers three phase-locked Q outputs (Q0–Q2) with <500ps output-to-output skew, a 2X_Q output at up to 70MHz, and integrated processor reset functionality via RST_IN/RST_OUT(LOCK). Its SOIC-20 package supports industrial temperature range (–40°C to +85°C) and 5V ±10% supply operation.

For engineers reviewing the MC88916DW70 datasheet, MC88916DW70 pinout, MC88916DW70 application, or MC88916DW70 equivalent, key selection criteria include guaranteed 35MHz Q-output frequency, 70MHz 2X_Q maximum, sub-1ns total output skew across six outputs (Q0–Q2, Q3, 2X_Q, Q/2), ±36mA CMOS/TTL-compatible drive strength, and RST_OUT lock-indicator timing aligned to 1024 Q-cycles.

Technical Context

The MC88916DW70 implements a fully integrated PLL with internal feedback (no external loop filter pins), locking all outputs-including Q0–Q2, Q3 (180° inverted), 2X_Q, and Q/2-to the SYNC input with fixed 2× multiplication from Q to SYNC. Its VCO operates at 2X_Q frequency, and the PLL_EN pin disables the VCO for static test mode, removing frequency limits on SYNC input during board-level testing.

Phase-lock acquisition time is 1–10ms; the RST_OUT(LOCK) pin serves dual purpose as open-drain reset indicator and processor reset signal, asserting low for exactly 1024 Q-output cycles after RST_IN returns high. The device uses analog/digital power separation (AVCC/GND pins) and requires a 1MΩ RC1 reference resistor to suppress jitter and control phase offset between SYNC and Q outputs.

Key Specifications

Pinout & Package

MC88916DW70 is housed in a 20-lead SOIC package (Case 751D–04, DW suffix), 7.60 mm × 12.95 mm body size, with standard 1.27 mm lead pitch. Pin 1 is located at top-left corner (notch-marked side), and the package features separate analog and digital power/ground pins (AVCC, GND(AN)) for noise isolation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC88916DW80, the MC88916DW70 trades 10MHz 2X_Q headroom for identical cost, footprint, and feature set in 35MHz-limited applications; versus MC88920DW, it offers integrated reset and broader frequency flexibility at the expense of dedicated PCLK duty-cycle hardening.

Availability

MC88916DW70 is available at Aetrix Electronics and suitable for legacy 68030/040 embedded control, industrial automation, and retro-computing restoration projects requiring stable component supply and long-term obsolescence management.

Supply support for MC88916DW70 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

Freescale Semiconductor (now part of NXP Semiconductors) developed high-reliability timing solutions for Motorola's microprocessor ecosystem, emphasizing low-jitter, low-skew clock distribution in mixed-signal environments.

The MC88916 belongs to Freescale's Timing Solutions product line, engineered specifically to support Motorola's 68000-family processors with integrated PLL-based clock synthesis, processor reset logic, and robust noise immunity for industrial-grade applications.

FAQ

What is the maximum guaranteed frequency for the Q outputs of the MC88916DW70?

The MC88916DW70 guarantees a maximum operating frequency of 35 MHz for its Q0–Q2 and Q3 outputs. This rating applies under phase-locked conditions with all outputs loaded at 50Ω terminated to VCC/2. The 35 MHz limit ensures compliance with setup/hold timing for MC68030 and 33/40 MHz MC68040 system clocks, and is directly derived from the 70 MHz 2X_Q maximum divided by two.

How does the RST_OUT(LOCK) pin function in the MC88916DW70?

The RST_OUT(LOCK) pin on the MC88916DW70 is an open-drain output serving dual roles: it indicates PLL lock status and generates processor reset signals. When RST_IN is held high during power-up, RST_OUT remains low until phase-lock is achieved, then transitions to high-impedance (requiring external pull-up). Toggling RST_IN low triggers a precise 1024-cycle low pulse on RST_OUT, synchronized to the Q output frequency-exactly matching MC68030/040 reset timing requirements.

Can the MC88916DW70 drive both CMOS and TTL logic inputs?

Yes, the MC88916DW70 can drive both CMOS and TTL inputs. All outputs deliver ±36 mA drive strength with CMOS voltage levels (VOH ≥ 4.01 V, VOL ≤ 0.44 V at VCC = 5.0 V), which exceed TTL input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V). Its outputs are explicitly specified as TTL-level compatible, and the ±36 mA sourcing/sinking capability ensures reliable interfacing with mixed-logic families without level-shifting circuitry.

What is the purpose of the RC1 pin on the MC88916DW70?

The RC1 pin on the MC88916DW70 connects to an external 1 MΩ resistor (tied to AVCC or AGND) to inject controlled current into the internal PLL charge pump. This current sets the VCO gain and eliminates dead-band-induced jitter, ensuring stable low-phase-noise operation. The resistor value is critical: 1 MΩ is required for VCO frequencies above 40 MHz (e.g., 70 MHz 2X_Q), while 1.5 MΩ is recommended below 40 MHz to maintain optimal charge pump bias.

Is the MC88916DW70 pin-compatible with the MC88916DW80?

Yes, the MC88916DW70 is pin-compatible with the MC88916DW80. Both devices share identical 20-lead SOIC (DW) packaging, pinout configuration, electrical specifications (except frequency ratings), and functional block diagram. The only difference is the maximum 2X_Q output frequency-70 MHz for MC88916DW70 and 80 MHz for MC88916DW80-making them direct drop-in replacements where frequency margin is not required.