S-93C46 Serial EEPROM Data Breakdown: Pinout & Specs
The S-93C46 is a compact, three-wire nonvolatile memory device commonly used for small configuration and calibration stores. Offering a 1-Kbit organization, it supports clock rates up to 2.0 MHz and accepts supply voltages from 1.6V to 5.5V. This breakdown provides actionable insights into the S-93C46 pinout, electrical parameters, and integration logic for embedded systems.
1 — Technical Overview & Organization
The S-93C46 is a 1-Kbit class EEPROM with a versatile Microwire interface. Its primary feature is the ORG pin, which allows the memory to be configured as either 64 words × 16 bits or 128 words × 8 bits. Firmware must strictly match the address width to the hardware-strapped ORG state to prevent data misalignment.
| Parameter | Specification | Condition / Note |
|---|---|---|
| Memory Capacity | 1,024 bits (1 Kbit) | Selectable 8/16-bit word |
| Supply Voltage (Vcc) | 1.6V to 5.5V | Wide range for battery apps |
| Max Clock Frequency | 2.0 MHz | At Vcc ≥ 4.5V |
| Write Cycle Time | 4.0 ms (Typ.) | Self-timed internal cycle |
| Endurance | 100,000+ Cycles | Per word address |
2 — Pinout & 3-Wire Interface Logic
The interface relies on CS (Chip Select) being pulled high during the entire transaction. SK (Serial Clock) synchronizes data input on DI and output on DO. Note that the ORG pin should be tied to VCC for x16 mode or GND for x8 mode; leaving it floating can cause unpredictable addressing behavior.
3 — Implementation & Troubleshooting FAQ
What is the recommended check for addressing errors?
Misaddressing usually stems from incorrect ORG handling. Verify the ORG pin state on hardware and ensure firmware uses the proper address-bit width (7 bits for x8, 6 bits for x16). Testing with a logic analyzer is recommended to confirm the start bit and opcode timing.
How should firmware verify a completed write?
You can either poll the DO pin (which stays Low during internal programming and goes High when Ready) or implement a fixed delay of at least 10ms to ensure the internal write cycle is complete before the next command is issued.
What are quick lab tests to validate a variant?
Before production, validate the supply voltage tolerance (especially at 1.6V), check signal integrity on the SK line to avoid double-clocking, and perform a burn-in test by cycling writes to the same address to verify the specified endurance.
When should the S-93C46 be selected over Flash?
Choose the S-93C46 for extremely small data sets (like serial numbers or calibration offsets) where the complexity of a SPI/I2C stack is overkill. It offers superior byte-level write control and lower standby current for battery-constrained devices.
Summary Checklist
For a successful S-93C46 integration:
- Tie ORG pin high or low; do not leave it floating.
- Place a 0.1 µF decoupling capacitor as close to Pin 8 (VCC) as possible.
- Ensure the Start Bit (1) is always the first bit clocked in for any command.
- Verify timing margins for CS setup before the first clock pulse.
