Diodes Incorporated PT8A978BPE

Overview

PT8A978BPE from Pericom Semiconductor is a 5-function infrared/RF remote control decoder IC designed for toy-grade RC systems. It features five dedicated output pins (VO1–VO5) for forward/backward/left/right/turbo actions, on-chip 3-stage fault-tolerant amplification, internal oscillator with external resistor tuning (102–154 kHz), and operates from 2.5V to 5.0V. Used in battery-powered remote-controlled toys requiring low-power decoding of encoded command streams.

For engineers reviewing the PT8A978BPE datasheet, PT8A978BPE pinout, PT8A978BPE application, or PT8A978BPE equivalent, this device requires attention to oscillator frequency matching with its companion encoder PT8A977B, SI input sensitivity (300 mVpp), and output drive capability (±200 µA at VO pins) in IR receiver front-end designs.

Technical Context

The PT8A978BPE implements a synchronous decoding architecture where incoming serial data on the SI pin is amplified by three cascaded stages, sampled against timing derived from an internal oscillator, and validated via fault-tolerant logic before latching decoded function states. Oscillator frequency must match the PT8A977B encoder within ±25% for reliable frame synchronization.

It integrates pull-up-enabled control inputs (LD, RD) to disable left/right functions, supports external resistor-based oscillator tuning (R = 200 kΩ typical), and delivers discrete CMOS-level outputs without internal drivers-requiring external transistors or H-bridge interfaces for motor control.

Key Specifications

Pinout & Package

PT8A978BPE is available in 16-pin DIP and 16-pin SOIC packages. The "PE" suffix denotes Pb-free, RoHS-compliant packaging.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar remote control decoder applications.

Compared with PT8A978BLPE, the PT8A978BPE offers higher minimum supply voltage but lower oscillator drift tolerance - making it optimal for stable 4.5–5 V alkaline systems. Versus PT2272-M4, it provides integrated amplification and IR/RF flexibility at the cost of non-standard protocol encoding.

Availability

PT8A978BPE is available at Aetrix Electronics and suitable for RC toy development, IR receiver module production, and low-cost RF remote control systems requiring stable component supply and long-lifecycle support.

Supply support for PT8A978BPE 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

Pericom Semiconductor (now part of Diodes Incorporated) specialized in high-performance interface, timing, and connectivity ICs for consumer and computing markets.

The PT8A97xx series was designed specifically for cost-sensitive, battery-operated remote control toys - prioritizing ultra-low standby current, minimal external components, and robust decoding under marginal signal conditions.

FAQ

What is the required external resistor value for nominal 128 kHz oscillator operation?

The PT8A978BPE achieves 128 kHz nominal oscillator frequency with a 200 kΩ resistor connected between VCC and the OSCI pin. Resistor tolerance should be ≤5% to maintain ±25% matching with PT8A977B encoder. Temperature coefficient ≤100 ppm/°C is recommended to limit drift across −10°C to +40°C ambient.

Can PT8A978BPE decode signals from encoders other than PT8A977B?

No - PT8A978BPE is designed exclusively for use with PT8A977B encoder. Its timing generator expects specific start-code (1.5–2.5 ms) and function-code (0.75–1.25 ms) durations, carrier frequencies (51–77 kHz on SC pin), and frame structure. Non-matching encoders will fail synchronization or produce invalid outputs.

How is the SI input protected against ESD or overvoltage?

The SI pin has no built-in ESD protection diodes per datasheet maximum ratings. External 5.6 V Zener clamp and series 100 Ω resistor are recommended before SI to prevent damage from static discharge or receiver-stage overshoot. Absolute maximum input voltage is −0.5 V to +6.0 V - exceeding this risks latch-up or permanent failure.

Does PT8A978BPE support simultaneous multi-function activation (e.g., forward + turbo)?

Yes - the decoding circuit recognizes combinations of button presses encoded by PT8A977B. When both Forward and Turbo inputs are asserted simultaneously on the encoder, PT8A978BPE asserts VO1 (Forward) and VO4 (Turbo) concurrently. Output timing remains synchronized to the same oscillator, ensuring deterministic concurrent activation.