Renesas ICM7228CIPI

Overview

ICM7228CIPI from Intersil is an 8-digit, microprocessor-compatible LED display decoder driver with parallel random-access RAM write capability, common anode output configuration, and support for hexadecimal and Code B display formats. It integrates digit/segment drivers, 8-byte static RAM, multiplex oscillator, and non-overlapping digit drive - enabling direct interface to 7-segment LED panels in instrumentation and test equipment operating from -40°C to +85°C.

For engineers reviewing the ICM7228CIPI datasheet, ICM7228CIPI pinout, ICM7228CIPI application, or ICM7228CIPI equivalent, this device delivers deterministic 200ns write access, on-chip segment/digit drive (200mA digit, 25mA segment), three-level input control for shutdown/format selection, and compatibility with 5V TTL/CMOS microprocessor buses without wait states.

Technical Context

The ICM7228CIPI implements a dedicated 8-digit × 7-segment + DP LED driving architecture with integrated 8-byte static RAM, multiplex oscillator, and decode logic. Its parallel random-access data entry uses DA0–DA2 address inputs and ID0–ID3 + ID7 data lines, eliminating sequential update overhead.

Unlike ICM7228A/B variants, it omits the MODE-controlled control register and No Decode mode, relying solely on the three-level HEXA/CODE B/SHUTDOWN input (Pin 9) for format selection and shutdown - simplifying software interface but removing per-digit decode-mode flexibility.

Key Specifications

Pinout & Package

ICM7228CIPI is housed in a 28-lead plastic dual in-line package (PDIP), pin-compatible with other ICM7228 variants in PDIP form factor (Package Drawing E28.6). The device uses standard through-hole wave solder processing; Pb-free variant (ICM7228CIPIZ) is not reflow-compatible.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICM7228CIBIZ, ICM7228CIPI offers identical performance in a wave-solder-friendly PDIP package, while ICM7218C demands more control pins and lacks the integrated three-level function pin - making ICM7228CIPI preferable for new designs prioritizing simplicity and thermal robustness.

Availability

ICM7228CIPI is available at Aetrix Electronics and suitable for instrumentation panels, test equipment displays, and industrial handheld devices requiring stable component supply with long-term obsolescence mitigation.

Supply support for ICM7228CIPI 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

Intersil (now part of Renesas Electronics) is a semiconductor manufacturer specializing in precision analog, power management, and interface ICs for industrial, test, and embedded applications.

The ICM7228 product line was designed to simplify LED display interfacing in microprocessor-based instruments - integrating RAM, decoding, multiplexing, and drive circuitry into a single 28-pin IC to reduce system component count and firmware complexity.

FAQ

What display formats does the ICM7228CIPI support?

The ICM7228CIPI supports Hexadecimal and Code B display formats only, selected via the three-level HEXA/CODE B/SHUTDOWN input (Pin 9). Unlike ICM7228A/B variants, it does not implement the No Decode mode - meaning segment-by-segment control is not available. Hexadecimal mode displays 0–9, A–F; Code B maps the same 4-bit codes to 0–9 and blank characters as defined in Table 5 of the FN3160 datasheet. The ICM7228CIPI retains full compatibility with these two formats while streamlining the control interface.

How does the ICM7228CIPI handle digit addressing during data writes?

The ICM7228CIPI uses three dedicated address inputs - DA0 (Pin 5), DA1 (Pin 6), and DA2 (Pin 10) - to select one of eight RAM locations corresponding to digits 1 through 8. Before each WRITE pulse, the host microprocessor sets the desired digit address on these pins; the rising edge of WRITE then latches both the address and the 4-bit display data (ID0–ID3) plus decimal point control (ID7) into that specific digit's RAM location. This parallel random-access method avoids sequential bus cycles and internal address counters used in ICM7228A/B variants, reducing software overhead and improving update determinism for the ICM7228CIPI.

What is the purpose of the three-level input on Pin 9 of the ICM7228CIPI?

Pin 9 of the ICM7228CIPI is the HEXA/CODE B/SHUTDOWN input - a single three-level control pin that replaces multiple discrete control bits found in earlier variants. When pulled high (>4.2V), it selects Hexadecimal decoding; when left floating or driven to ~2.0–3.0V, it selects Code B decoding; and when pulled low (<0.8V), it places the ICM7228CIPI into shutdown mode - disabling the oscillator and all drivers while retaining RAM data. This design reduces GPIO requirements and simplifies firmware state handling compared to ICM7228A/B, where format and shutdown were controlled separately via ID4–ID6 bits in a control register.

Can the ICM7228CIPI drive common-cathode LED displays?

No, the ICM7228CIPI is configured exclusively for common-anode LED displays. Its digit outputs are N-channel sinks (capable of 200mA per digit), and its segment outputs are P-channel sources (25mA peak per segment), matching the current flow requirements of common-anode topologies. Common-cathode operation requires opposite driver polarity - which is implemented only in the ICM7228B family variants. Attempting to use the ICM7228CIPI with common-cathode displays will result in incorrect or no illumination. For common-cathode applications, ICM7228BIPI or ICM7228BIBI should be selected instead.

What are the key differences between ICM7228CIPI and ICM7228AIPI?

The ICM7228CIPI uses parallel random-access data entry with DA0–DA2 address lines and lacks a MODE pin or control register, whereas the ICM7228AIPI relies on sequential 8-digit updates or single-digit mode using a MODE-controlled control register and ID0–ID7 data bus. The ICM7228CIPI omits No Decode mode and uses a three-level Pin 9 for format/shutdown, while the ICM7228AIPI uses discrete ID4–ID6 bits. Both share the same common-anode output structure, 28-pin PDIP package, -40°C to +85°C rating, and 200ns write timing - but their firmware interfaces and feature sets are mutually incompatible.