NXP Semiconductors MC88LV926DWR2

Overview

MC88LV926DWR2 from Motorola is a low-skew CMOS PLL clock driver designed for CISC and single-processor RISC systems, specifically supporting the MC68030/040/060 microprocessor families. It delivers three synchronized Q outputs (Q0–Q2) with <500ps output-to-output skew, a 2X_Q output at up to 66MHz, and integrated reset functionality via RST_IN/RST_OUT(LOCK). It operates from 3.3V ±0.3V and supports both 3.3V and 5.0V supply configurations.

For engineers reviewing the MC88LV926DWR2 datasheet, MC88LV926DWR2 pinout, MC88LV926DWR2 application, or MC88LV926DWR2 equivalent, key selection considerations include its fixed 2× frequency multiplication, guaranteed phase-lock acquisition time of ≤10ms, open-drain RST_OUT(LOCK) with 1024-cycle reset hold, and SOIC-20 DW package compatibility with 68060 system timing requirements.

Technical Context

The MC88LV926DWR2 implements a fully integrated PLL with internal feedback - no external feedback pin - fixing the relationship between SYNC input and Q/2X_Q outputs at 2× multiplication. Its VCO locks to SYNC frequencies from 5MHz to 33MHz (for 66MHz 2X_Q), and all outputs are driven with ±36mA CMOS-level current.

It features dedicated logic for 68060 bus timing: QCLKEN provides a half-speed clock skewed relative to 2X_Q to meet CLKEN setup/hold requirements, while RST_IN/RST_OUT(LOCK) serves dual roles - processor reset initiation and PLL lock indication - with precise 1024-Q-cycle assertion timing and open-drain output requiring external pull-up.

Key Specifications

Pinout & Package

MC88LV926DWR2 is housed in a 20-lead plastic SOIC (DW suffix, Case 751D), with 4 VCC pins (pins 4, 7, 11, 20), 3 GND pins (pins 1, 12, 18), and dedicated analog power/ground (VCC(AN) at pin 11, GND(AN) at pin 13) for PLL stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC88LV926DWR2, the MC88LV925DWR2 offers simpler clock multiplication but omits critical 68060 support features like QCLKEN skew control and lock-indicated reset, while the ICS83021AGI-01LFT provides higher-speed LVDS outputs but lacks native compatibility with Motorola microprocessor timing interfaces and reset protocols.

Availability

MC88LV926DWR2 is available at Aetrix Electronics and suitable for 68060-based industrial controllers, legacy test equipment upgrades, and embedded systems requiring stable, low-skew clock distribution with integrated reset coordination.

Supply support for MC88LV926DWR2 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

Motorola (now part of NXP Semiconductors) was a pioneer in microprocessor support ICs and timing solutions for embedded computing systems.

The MC88LV926DWR2 belongs to Motorola's Timing Solutions product line, engineered specifically to simplify clock tree design and reset sequencing for the MC68030/040/060 family in industrial and test equipment applications.

FAQ

What is the maximum operating frequency of the 2X_Q output on the MC88LV926DWR2?

The MC88LV926DWR2 guarantees a maximum 2X_Q output frequency of 66MHz under phase-locked conditions with VCC = 3.3V ±0.3V or 5.0V ±5%. This meets the PCLK input specifications for both 50MHz and 66MHz versions of the MC68060 microprocessor, including strict duty cycle and rise/fall time requirements.

How does the RST_OUT(LOCK) pin function on the MC88LV926DWR2?

The RST_OUT(LOCK) pin on the MC88LV926DWR2 serves a dual role: it acts as an open-drain lock indicator (pulled low until PLL achieves phase/frequency lock) and as a processor reset output. When RST_IN is toggled low and returned high, RST_OUT(LOCK) stays actively low for exactly 1024 cycles of the Q output frequency - satisfying the reset timing requirement of the 68030/040/060 family.

Can the MC88LV926DWR2 operate from a 5.0V supply?

Yes, the MC88LV926DWR2 is specified to operate from either 3.3V ±0.3V or 5.0V ±5% supply. Input voltage thresholds scale accordingly (e.g., VIH minimum becomes 2.7V when VCC > 4.0V), while output drive strength and AC timing remain consistent. The device maintains full functionality and parameter guarantees across both supply voltages.

What is the purpose of the RC1 pin on the MC88LV926DWR2?

The RC1 pin on the MC88LV926DWR2 connects to the external PLL loop filter (typically 330Ω + 0.1µF capacitor). It sets VCO control voltage and determines lock stability, acquisition time, and jitter performance. A 470kΩ reference resistor tied to RC1 injects current into the charge pump to eliminate dead-band jitter - especially critical when the 2X_Q output exceeds 40MHz.

Does the MC88LV926DWR2 support programmable frequency multiplication?

No, the MC88LV926DWR2 implements fixed 2× frequency multiplication from the SYNC input to the 2X_Q output, with Q0–Q2 running at the same frequency as SYNC. The feedback path is internal and hardwired - there are no configuration pins, registers, or external feedback options to alter the multiplication ratio or output frequencies.