Renesas HN27C101AG12

Overview

HN27C101AG12 from Hitachi is a 1-Mbit (131072-word × 8-bit) UV-erasable, electrically programmable ROM in a 32-pin cerdip package with transparent lid. It operates on +5 V ±10%, supports 120 ns access time, and delivers TTL-compatible I/O during both read and program modes for embedded firmware storage in legacy microcontroller systems.

For engineers reviewing the HN27C101AG12 datasheet, HN27C101AG12 pinout, HN27C101AG12 application, or HN27C101AG12 equivalent, key selection criteria include UV-erase compatibility, 12.5 V programming voltage, JEDEC-standard 32-pin DIP footprint, and fast high-reliability page programming at 14 sec typical - critical for field-upgradable industrial control PROMs.

Technical Context

This EPROM implements a 1024 × 1024 memory matrix with X- and Y-decoding architecture, supporting full address range A0–A16 and bidirectional data I/O0–I/O7. Its dual-mode operation-standard read (VPP = VCC) and programming (VPP = 12.5 V, VCC = 6.0 V)-requires strict sequencing per tVPS/tVCS timing to prevent reliability degradation.

Device identifier mode uses A9 = 12.0 V ±0.5 V and A0 logic levels to output manufacturer code 07h and device code 38h on I/O7–I/O0, enabling automatic algorithm selection in compatible programmers. Erasure requires ≥15 W·sec/cm² UV dose at 2537 Å to reset all bits to '1'.

Key Specifications

Pinout & Package

Package: 600-mil 32-pin ceramic dual-in-line package (DG-32) with UV-transparent quartz window lid per JEDEC MS-011.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AM27C101-12DC and MX27C101-12PC, the HN27C101AG12 uniquely balances field-upgradability (via UV erasure), moderate 12.5 V programming voltage, and JEDEC-standard cerdip packaging - making it optimal for repairable, mid-lifecycle industrial electronics where firmware revision is anticipated but flash infrastructure is absent.

Availability

HN27C101AG12 is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy microcontroller boot ROM, and test equipment calibration data applications requiring stable component supply across extended product lifecycles.

Supply support for HN27C101AG12 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

Hitachi Ltd. (now Renesas Electronics Corporation following 2003 merger) was a Japanese semiconductor pioneer known for high-reliability memory and logic devices targeting industrial and automotive markets.

The HN27C101AG series was designed specifically for embedded systems requiring field-erasable, pin-compatible replacements for mask ROMs - emphasizing UV endurance, TTL interoperability, and robust programming algorithms for manufacturing and service environments.

FAQ

What is the programming voltage requirement for HN27C101AG12?

HN27C101AG12 requires +12.5 V DC applied to the VPP pin during programming and verify operations, with strict sequencing: VCC must be applied before VPP and removed after VPP. This voltage is distinct from the +5 V ±10% VCC supply used during read mode. Exceeding 13.5 V on VPP risks reliability degradation, and altering VPP while CE is low is prohibited per datasheet safety rules.

Does HN27C101AG12 support page programming, and how long does it take?

Yes, HN27C101AG12 supports fast high-reliability page programming with a typical duration of 14 seconds for the full 1-Mbit array. This mode uses an adaptive overprogramming pulse-width algorithm (tOPW = 0.2n ms) that avoids voltage stress while ensuring data integrity. The process requires VPP = 12.5 V and VCC = 6.0 V, and is controlled via PGM, CE, and OE signals per the documented flowchart.

How is the HN27C101AG12 erased, and what UV specification is required?

HN27C101AG12 is erased by exposing its quartz window to ultraviolet light at 2537 Å wavelength. The minimum required integrated dose is 15 W·sec/cm² - achieved, for example, by 20–30 minutes under a standard 12 mW/cm² UV lamp. Erasure resets all memory bits to logic '1'. Devices must be erased before reprogramming, and incomplete erasure causes verify failures during subsequent programming cycles.

What are the key timing parameters for HN27C101AG12 read operations?

For HN27C101AG12 read operations at 120 ns speed grade: address-to-output delay (tACC) is ≤120 ns, CE-to-output delay (tCE) is ≤120 ns, and OE-to-output delay (tOE) is ≤60 ns. All values assume VCC = +5 V ±10%, Ta = 0°C to +70°C, and load of 1 TTL gate + 100 pF. Input rise/fall times must be ≤20 ns, and reference voltage levels for timing measurements are 0.8 V and 2.0 V.

Can HN27C101AG12 be used as a direct replacement for mask ROMs in existing designs?

Yes, HN27C101AG12 is explicitly designed as a 32-pin JEDEC-standard replacement for 1-Mbit mask ROMs, sharing identical pinout, TTL-compatible I/O, and +5 V operation. Its CE/OE dual-control architecture matches standard ROM timing, and the 120 ns access time meets or exceeds many legacy mask ROM specs. However, VPP routing and UV window clearance must be added to the PCB layout if replacing a non-erasable part.