Microchip Technology 47C16-I/SN

Overview

47C16-I/SN from Microchip Technology is a 16 Kbit (2,048 × 8) I²C serial EERAM combining volatile SRAM with nonvolatile EEPROM backup. It operates at 4.5–5.5 V, supports up to 1 MHz I²C, and delivers automatic power-loss data retention via external VCAP capacitor. Its hardware Store pin (HS), software-controlled Store/Recall, and configurable write protection make it ideal for industrial control logging and automotive event recorders requiring deterministic nonvolatile storage without battery or FRAM.

For engineers reviewing the 47C16-I/SN datasheet, 47C16-I/SN pinout, 47C16-I/SN application, or 47C16-I/SN equivalent, key selection criteria include its 25 ms max Store time, 5 ms Recall duration, 40 µA max standby current, Schmitt-triggered I²C inputs for noise immunity, and AEC-Q100-qualified operation across –40°C to +85°C.

Technical Context

The 47C16-I/SN implements a dual-memory architecture: a 2,048 × 8-bit SRAM array for high-speed read/write access and a matching EEPROM array for persistent backup. Data transfer between them is triggered by power loss (via VCAP voltage monitoring at 4.0–4.4 V trip point), hardware pulse on HS pin (≥150 ns), or software command (0x55 + 0x33 for Store, 0x55 + 0xDD for Recall).

Its I²C interface complies with standard 100 kHz/400 kHz/1 MHz modes, features zero-cycle-delay reads/writes, and supports cascading up to four devices using A1/A2 address pins. The STATUS register (address 0x00) provides nonvolatile control of Auto-Store Enable (ASE), Block Protection (BP2:BP0), and Array Modified (AM) flag - enabling selective SRAM write protection down to 1/64 of the array (0x7E0–0x7FF).

Key Specifications

Pinout & Package

47C16-I/SN is supplied in an 8-lead SOIC package (SN suffix), with 1.27 mm pitch, 5.0 mm × 6.2 mm body, and JEDEC MS-012AC compliance. Pin 1 is VCAP (external capacitor connection for Auto-Store), Pin 2 is A1 (device address bit), Pin 3 is A2 (device address bit), Pin 4 is VSS (ground), Pin 5 is VCC (power), Pin 6 is HS (Hardware Store input), Pin 7 is SCL (I²C clock), and Pin 8 is SDA (I²C data bidirectional).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 47C16-I/SN, 47L16-I/SN offers identical feature set at 3.3 V while FM24CL16B replaces EEPROM backup with F-RAM for zero-latency writes - but sacrifices the hardware-triggered Store capability and 5 V operation critical for industrial 5 V bus environments.

Availability

47C16-I/SN is available at Aetrix Electronics and suitable for industrial data loggers, automotive event recorders, smart meter tamper logs, and medical device configuration stores requiring stable component supply across extended product lifecycles.

Supply support for 47C16-I/SN 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

Microchip Technology Inc. is a global semiconductor company specializing in microcontrollers, analog devices, and memory solutions for industrial, automotive, and consumer markets.

The 47C16-I/SN belongs to Microchip's EERAM family - designed specifically to replace battery-backed SRAM and simplify nonvolatile data logging in resource-constrained embedded systems.

FAQ

What is the primary function of the VCAP pin on the 47C16-I/SN?

The VCAP pin on the 47C16-I/SN connects to an external 5–6.8 µF capacitor that supplies energy during VCC collapse, enabling automatic SRAM-to-EEPROM Store operation without host intervention. When VCC drops below the 4.0–4.4 V trip threshold, the 47C16-I/SN uses stored charge on the VCAP capacitor to complete the Store within 25 ms. If no capacitor is used, VCAP must be tied to VCC and Auto-Store disabled to prevent EEPROM corruption.

How does the Hardware Store (HS) pin differ from Software Store commands on the 47C16-I/SN?

The HS pin on the 47C16-I/SN provides a hardware-level trigger for immediate SRAM-to-EEPROM Store, requiring only a ≥150 ns active-high pulse - independent of I²C bus activity or firmware execution. In contrast, Software Store (0x55 + 0x33) requires a valid I²C transaction and is subject to bus arbitration and timing delays. Both methods clear the AM bit upon completion, but HS bypasses the AM flag check and executes unconditionally.

Can the 47C16-I/SN operate without an external capacitor on the VCAP pin?

Yes, the 47C16-I/SN can operate without an external capacitor on VCAP if Auto-Store is disabled (ASE = 0) and VCAP is tied directly to VCC. In this mode, Store operations rely solely on the HS pin or Software Store commands. However, automatic power-loss backup is disabled, and the device loses its defining EERAM behavior - effectively functioning as a standard I²C SRAM with optional EEPROM backup initiated only on demand.

What is the significance of the AM (Array Modified) bit in the STATUS register of the 47C16-I/SN?

The AM bit in the 47C16-I/SN STATUS register indicates whether the SRAM contents differ from the EEPROM backup: '1' means at least one write has occurred since the last Store or Recall, '0' means they match. Auto-Store and Hardware Store require AM = 1 to execute; Software Store does not. The AM bit is volatile (cleared automatically after Store/Recall) and serves as a hardware-managed dirty flag - eliminating the need for host firmware to track memory state.

Which I²C address bits are configurable on the 47C16-I/SN, and how many devices can share one bus?

The 47C16-I/SN uses A1 and A2 pins (Pins 2 and 3) to configure the two least-significant bits of its 7-bit I²C client address (base op-code 1010xxx0). With A1/A2 grounded, pulled high, or left floating (internally pulled down), up to four 47C16-I/SN devices can coexist on the same I²C bus. Each device responds only to its unique address, enabling scalable multi-node logging without address conflicts.