4505 64-BIT, 1-BIT PER WORD RANDOM ACCESS MEMORY (RAM) DIP-14
The HEF4505B is a fully decoded, static 64-bit random access memory implemented as 1-bit per word cells in a 14-lead DIP package. Designed in Philips’ LOCMOS process, it provides simple, low-power storage for small memories where density is low but access control and robustness matter. The device exposes six address lines to select one of 64 locations, a single data input, and a single data output, plus dedicated control pins for strobe and chip enables.
Reads and writes occur only when the strobe (ST) and chip-enable inputs (CE1 and CE2) are asserted appropriately, allowing precise timing control and easy expansion by tying outputs together. The output goes to a defined low state before data becomes valid and can be placed in a high-impedance OFF state for bus sharing. Very low leakage and standby dissipation make the HEF4505B attractive for battery-sustained or trickle-charged backup arrangements.
Because the memory is static and fully decoded, no external refresh is required and system wiring is straightforward. Typical use emphasizes small lookup tables, register storage, and low-power nonvolatile-style retention (with a small battery) rather than high-density storage. The DIP-14 form factor and standard pinout simplify prototyping and replacements in legacy boards.
Features:
- 64 bits total capacity, organized as 1 bit per word.
- Fully decoded static RAM (no refresh required).
- Single data input and single data output per IC.
- Strobe (ST) plus dual chip-enable (CE1, CE2) control for precise access gating.
- Three-state output for easy bus sharing.
- Very low standby current suitable for battery-backed retention.
- LOCMOS low-power technology.
- Available in 14-lead DIP (plastic and ceramic options).
Specifications:
| Parameter | Value |
|---|---|
| Device / Package: | HEF4505B — 14-lead DIL (plastic: HEF4505BP(N); ceramic: HEF4505BD(F)) |
| Memory capacity: | 64 bits (1 bit per word) |
| Organization: | Fully decoded static RAM |
| Address inputs: | A0 … A5 (6 address lines → 64 addresses) |
| Data pins: | DIN (data input), DOUT (data output, three-state) |
| Control pins: | CE1, CE2 (chip enables), ST (strobe), R/W (read/write) |
| Supply voltage (operating): | VDD = 4.5 V to 15 V |
| Minimum standby voltage for retention: | 3 V (minimum for data retention) |
| Typical read access time: | See datasheet (AC characteristics depend on VDD and load; read access typically tens-to-hundreds ns). |
| Typical write/read cycle behavior: | Read/write gated by ST with defined setup/hold and recovery times (see datasheet). |
| Temperature / Ratings: | Standard commercial ratings per data sheet; refer to product specification for limits. |
Pinout:
Applications:
- Small static RAM / register storage.
- Battery-backed memory cells.
- Lookup tables and fixed parameter stores.
- Memory expansion (parallel/stacked arrays).
- Microcontroller peripheral buffering.
- Low-speed logic and state storage in legacy systems.
Package Contents:
- 1x 4505 64-BIT, 1-BIT PER WORD RANDOM ACCESS MEMORY (RAM) DIP-14
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