NXP Semiconductors PCF8578H/1,157

Overview

PCF8578H/1,157 from NXP Semiconductors (formerly Philips) is a low-power CMOS LCD row/column driver IC designed for dot matrix graphic displays operating at 1:8 to 1:32 multiplex rates. It provides 40 configurable outputs (32/8, 24/16, 16/24, or 8/32 row/column split), 1280-bit display RAM, I²C-bus interface, and on-chip oscillator requiring only one external resistor. It serves as a stand-alone controller for small displays or as the master timing and synchronization unit for up to 32 cascaded PCF8579 drivers in automotive information systems.

For engineers reviewing the PCF8578H/1,157 datasheet, PCF8578H/1,157 pinout, PCF8578H/1,157 application, or PCF8578H/1,157 equivalent, this page delivers verified technical context, exact pin functions for LQFP64 package, real-world configuration trade-offs between mixed and row modes, confirmed bias voltage generation requirements per multiplex rate, and validated alternatives with documented functional differences.

Technical Context

The PCF8578H/1,157 implements a dual-role architecture: in mixed mode it drives both rows and columns using its full 40-output capability and accesses internal 32×40-bit RAM; in row mode it configures all programmable outputs (R8/C8–R31/C31) as row drivers and generates synchronized CLK and SYNC signals for cascaded PCF8579s. Its I²C-bus controller supports two slave addresses (0x78/0x79) selected via SA0, and operates with TTL/CMOS-compatible logic levels across 2.5–6 V supply.

Timing is governed by an internal oscillator (frequency set by ROSC resistor, typically 330 kΩ) or external clock input at CLK pin. The device produces frame-synchronized output waveforms compliant with LCD RMS voltage requirements - e.g., for 1:16 multiplexing, V_on(rms)/V_op = 0.316 and V_off(rms)/V_op = 0.254 - and supports selectable 5- or 6-level bias via external resistor divider connected to V2–V5 pins.

Key Specifications

Pinout & Package

PCF8578H/1,157 is packaged in a plastic low-profile quad flat package (LQFP64) with 64 leads, body size 10 × 10 × 1.4 mm (SOT314-2). Pin assignments are optimized for single-plane PCB routing in multi-driver configurations.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LCD row/column driver applications.

Compared with PCF8579T/1,157, the PCF8578H/1,157 provides full stand-alone capability and integrated timing, while HD44102P offers higher native resolution but demands more host resources and external components - making PCF8578H/1,157 optimal for I²C-based embedded systems needing scalability and low component count.

Availability

PCF8578H/1,157 is available at Aetrix Electronics and suitable for automotive information systems, point-of-sale terminals, and telecommunication equipment requiring stable component supply and long-term industrial lifecycle support.

Supply support for PCF8578H/1,157 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 leader focused on secure connectivity solutions for automotive, industrial, and IoT applications. Formerly Philips Semiconductors, it maintains legacy product support with full documentation and long-term supply commitments.

The PCF8578H/1,157 belongs to NXP's legacy LCD controller/driver family, engineered specifically for monochrome dot-matrix graphic displays in resource-constrained embedded systems where low power, I²C simplicity, and cascade scalability are critical.

FAQ

What is the maximum display resolution supported by PCF8578H/1,157 in stand-alone mode?

The PCF8578H/1,157 supports up to 32 rows × 32 columns (1024 dots) in stand-alone mixed mode using its full 40-output capability - for example, 32 rows and 8 columns at 1:32 multiplex rate, or 16 rows and 24 columns at 1:16 rate. Resolution is constrained by the 1280-bit display RAM and fixed output allocation (R0–R7, C32–C39, plus 24 programmable pins).

How does the PCF8578H/1,157 generate LCD bias voltages?

The PCF8578H/1,157 does not generate bias internally. It accepts externally supplied 5- or 6-level bias voltages at pins V2–V5, derived from a resistor divider network connected between VLCD and VSS. The required voltage ratios depend on multiplex rate - e.g., for 1:16, V2/Vop = 0.600, V3/Vop = 0.316, V4/Vop = 0.254 - and must be decoupled with ≥1 µF capacitors per pin.

Can PCF8578H/1,157 operate without an external resistor on the OSC pin?

No. The PCF8578H/1,157 requires an external resistor (ROSC) connected between OSC and VSS to enable its internal oscillator. A value of 330 kΩ is recommended for nominal 12.288 kHz oscillator frequency. Leaving OSC unconnected or tied to VDD disables internal timing and forces external clock mode - which requires CLK signal injection and disables SYNC output functionality.

What happens to unused programmable outputs (R8/C8 to R31/C31) in row mode?

In row mode, all 24 programmable outputs (R8/C8 to R31/C31) are configured as row drivers, and the fixed column outputs C32–C39 must be left open-circuit. Unused row outputs beyond the configured multiplex count (e.g., R16–R31 in 1:16 mode) remain inactive but must still be connected to the LCD panel - they are driven to defined logic states to prevent floating nodes and EMI.

Is PCF8578H/1,157 compatible with modern 3.3 V microcontrollers?

Yes. The PCF8578H/1,157 supports logic supply VDD from 2.5 V to 6 V and features TTL/CMOS-compatible inputs, making it fully interoperable with 3.3 V microcontrollers. I²C lines (SDA/SCL) require pull-up resistors to the host's I²C bus voltage (typically 3.3 V), and no level-shifting circuitry is needed for standard-mode (100 kHz) operation.