NXP Semiconductors PCF8577CU/F3,026

Overview

PCF8577CU/F3,026 from NXP Semiconductors is an I²C-bus LCD segment driver supporting direct drive (32 segments) or duplex drive (64 segments), operating from 2.5 V to 6 V supply, featuring single-pin oscillator (A0/OSC), hardware subaddressing (A0–A2), and power-on reset. It targets low-power remote display interfaces in industrial control panels and portable instrumentation.

For engineers reviewing the PCF8577CU/F3,026 datasheet, PCF8577CU/F3,026 pinout, PCF8577CU/F3,026 application, or PCF8577CU/F3,026 equivalent, key selection criteria include I²C slave address (0x74), segment mapping in BANK A/B modes, BP1/BP2 backplane routing in duplex mode, and oscillator component sizing (ROSC = 1 MΩ, COSC = 680 pF).

Technical Context

The PCF8577CU/F3,026 implements a segmented LCD driver architecture with dual-mode operation: direct drive uses one backplane (BP1) and 32 segment outputs (S1–S32), while duplex drive requires two backplanes (BP1 and A2/BP2) and drives 64 segments via time-multiplexed waveform generation. Its I²C interface supports auto-incremented loading across up to eight cascaded devices for system expansion to 256 segments.

Control is managed through a 9-register memory map - one control register (MODE/BANK/SBV bits) and eight 8-bit segment byte registers split into BANK A (even addresses) and BANK B (odd addresses). The MODE bit selects drive mode; the BANK bit toggles displayed data bank; the Segment Byte Vector (SBV) enables device selection and register addressing via hardware subaddress lines A2–A0.

Key Specifications

Pinout & Package

PCF8577CU/F3,026 is housed in a plastic very small outline package (VSO40) with 40 leads, compliant with SOT158-1 standard. Package dimensions: 10.2 mm × 5.3 mm × 1.95 mm (max height), 0.65 mm lead pitch, gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCF8577CU/F3,026, PCF8576CT/3,118 offers simpler configuration but sacrifices duplex capability and system scalability, while MAX6955ATL+ provides charge-pump LCD biasing at the cost of segment count and direct/duplex flexibility - making PCF8577CU/F3,026 optimal for expandable, dual-mode industrial displays.

Availability

PCF8577CU/F3,026 is available at Aetrix Electronics and suitable for industrial control panels, portable medical instruments, smart energy meters, and automotive cabin displays requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for PCF8577CU/F3,026 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 is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The PCF8577C product line was designed specifically for low-power, I²C-interfaced LCD segment driving in space-constrained and battery-sensitive systems - emphasizing pin efficiency, flexible backplane routing, and robust ESD protection on bus lines.

FAQ

What is the I²C slave address of the PCF8577CU/F3,026?

The PCF8577CU/F3,026 has a fixed 7-bit I²C slave address of 0x74 (binary 0111010), as defined in Table 7 of the datasheet. The eighth bit is the R/W bit supplied by the master during transmission. This address is hardwired and cannot be altered via software or external pins - all PCF8577CU/F3,026 devices respond to this same address unless hardware subaddressing (A0–A2) is used to enable selective loading in multi-device systems.

How does the PCF8577CU/F3,026 support duplex LCD drive mode?

The PCF8577CU/F3,026 supports duplex drive mode by setting the MODE bit in its control register to logic 1. In this mode, it requires two backplane signals: BP1 (pin 33) and BP2 (pin 34, shared with A2). The device drives 64 segments using time-multiplexed waveforms where BANK A registers control segments tied to BP1 and BANK B registers control those tied to BP2. Unlike direct mode, the BANK bit is ignored, and SBV auto-increments by one per byte loaded.

Can the PCF8577CU/F3,026 be used as a general-purpose I²C output expander?

Yes, the PCF8577CU/F3,026 can function as a 32-bit I²C output expander. When configured in direct drive mode (MODE = 0) and BP1 is tied to VSS, the S1–S32 pins operate as open-drain outputs capable of sinking ≥0.3 mA each. The segment registers become general-purpose output latches, controllable via I²C writes - enabling use in LED drivers, relay controls, or status indicators without LCD-specific timing constraints.

What external components are required for the PCF8577CU/F3,026 oscillator?

The PCF8577CU/F3,026 requires two external passive components for its single-pin oscillator: a resistor (ROSC = 1 MΩ typical) and capacitor (COSC = 680 pF typical) connected between A0/OSC (pin 37) and VSS. Both must share the same VSS/VDD reference as the IC to ensure reliable startup. These components set the LCD modulation frequency to 65–120 Hz; values may be adjusted to fine-tune contrast or reduce EMI in noise-sensitive environments.

Does the PCF8577CU/F3,026 support cascading with other PCF8577C devices?

Yes, the PCF8577CU/F3,026 supports hardware-cascaded configurations using BP1 and A2/BP2 pins for synchronization. In cascade mode, one device acts as master oscillator (A0/OSC connected to RC network), while others have A0/OSC tied to VDD or VSS to disable local oscillation. Backplane signals are shared across all devices, enabling coordinated drive of up to 256 segments using eight PCF8577CU/F3,026 units - confirmed in Figure 13 of the datasheet.