24CW640T-I/CS1668 - 64Kbit I2C EEPROM, 1MHz, 4-CSP | Microchip
料号： 24CW640T-I/CS1668 ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.03 | $1.03 |
| 10 | $0.94 | $9.40 |
| 100 | $0.78 | $78.00 |
| 500 | $0.66 | $330.00 |
| 1,000 | $0.58 | $580.00 |
| 3,000 | $0.49 | $1,470.00 |
24CW640T-I/CS1668 概述
A serial EEPROM (Electrically Erasable Programmable Read-Only Memory) is a type of non-volatile memory IC that communicates over a simple two-wire bus. In the broader memory hierarchy, it sits between battery-backed SRAM and Flash, offering byte-level endurance (typically 1 million write cycles per page) and >200-year data retention at far lower pin count and cost than Flash. EEPROMs are commonly used to store configuration data, calibration coefficients, user preferences, and event logs that must survive power loss without the wear concerns of Flash.
Key features of the 24CW640 include a built-in power-on reset (POR), software write protection (via the SWP pin / block-protection bits), hardware write-protect (WP) input, noise-suppression input filter on SDA/SCL, page-write buffering (up to 64 bytes), and a Schmitt-triggered SCL input for slow edges. The 4-CSP (0.86 mm x 0.86 mm typical) form factor is one of the smallest footprints available for serial EEPROM and is intended for space-constrained designs such as wearables, hearables, and miniature sensor modules.
Architecturally, the device uses a CMOS floating-gate cell array with an integrated charge pump to support single-supply operation down to 1.8 V. The internal oscillator and timing state machine handle write-cycle management automatically, signaling completion via the I2C acknowledge polling mechanism, so the host MCU never needs to insert a fixed write delay beyond the page-write polling loop.
Typical applications include IoT sensor node configuration storage, BLE/Zigbee module parameter retention, consumer device user settings (e.g., white-balance or RF calibration), medical wearable identification, smart-card / NFC-tag pairing data, and industrial module serial-number programming. The wide VCC range and industrial temperature grade also make it suitable for automotive sub-systems and outdoor equipment where extended ambient conditions are routine.
When laying out the PCB, place the four CSP balls on a 4-ball land pattern with NSMD pads and route SDA/SCL as impedance-controlled lines with pull-ups to VCC. Note that WLCSP is sensitive to moisture (MSL-1); follow JEDEC J-STD-033 floor-life rules during assembly.
This page synthesizes distributor pricing, drop-in 4-CSP alternatives from Microchip's 24CW family, application notes, and design considerations not aggregated on any single manufacturer or distributor page.
直接替换替代料： 24CW640T-I/CS1668 ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
24CW640T-I/CS0668
✅ 直接替换📋 参考替代料（不在目录中）
24CW640T-I/CS1668 最大额定值与电气特性
| 存储器类型 | Non-volatile EEPROM (Serial) |
| 存储容量 | 64 Kbit (8 Kbyte) |
| Memory Organization | 8192 x 8 bits (8K x 8) |
| 接口 | I2C (2-wire serial, Standard / Fast / Fast-Plus) |
| 最大时钟频率 | 1 MHz (Fast-Plus mode) |
| Access Time | 450 ns (typical) |
| Supply Voltage (VCC) | 1.8 V to 5.5 V |
| 工作温度范围 | -40C to +85C (Industrial, "I" grade) |
| 封装 | 4-CSP / 4-XFBGA / CSPBGA (WLCSP, ~0.86 x 0.86 mm) |
| 安装类型 | Surface Mount (wafer-level CSP) |
| Page Write Buffer | 64 bytes |
| Power-On Reset (POR) | Built-in |
| Software Write Protection | Yes (SWP / block-protect bits) |
| Hardware Write Protect (WP) | Yes (active-high, tied to GND in CSP variant or unbonded) |
| SDA/SCL Noise Suppression | Yes (Schmitt-triggered input filter) |
| RoHS 状态 | Compliant |
24CW640T-I/CS1668 引脚配置
| 引脚 A1 | VCC — Power supply (1.8 V to 5.5 V) |
| 引脚 A2 | GND — Ground |
| 引脚 B1 | SDA — I2C serial data (bidirectional, open-drain) |
| 引脚 B2 | SCL — I2C serial clock input |
典型应用
24CW640T-I/CS1668 适用于 6 应用s: IoT Sensor Node Configuration Storage, Wearable and Hearable Device User Settings, Industrial Module Identification and Parameter Retention, Medical Wearable Identification and Logging, Consumer Device White-Balance and RF Calibration, Smart Card / NFC Tag Pairing Data Storage.
IoT Sensor Node Configuration Storage
The 24CW640T-I/CS1668 is well suited for IoT sensor nodes that store calibration coefficients, network credentials, and per-device serial numbers in non-volatile memory. The 8 Kbyte capacity comfortably holds multi-sensor calibration tables, security keys, and provisioning tokens for BLE / Zigbee / LoRa modules, while the 1 MHz I2C clock keeps bus transactions under 1 ms to minimise active-mode energy. With 1.8 V to 5.5 V single supply it ties directly to coin-cell, Li-ion, or USB-powered MCUs, and its 4-CSP footprint (under 1 mm x 1 mm) leaves the rest of the PCB for the radio and sensor front-end. Industrial -40C to +85C rating covers outdoor and cold-chain deployments.
推荐
Wearable and Hearable Device User Settings
In wearables such as fitness bands, smart watches, and TWS earbuds, board real-estate is precious and every square millimetre counts. The 24CW640T-I/CS1668's 4-CSP (WLCSP) package occupies roughly 0.86 mm x 0.86 mm - one of the smallest footprints available for any serial EEPROM - leaving room for the battery, BLE radio, and IMU. It reliably stores user-level preferences (EQ profiles, language, gesture maps) and factory calibration data such as accelerometer offset/gain, with 1.8 V operation compatible with the Li-ion/coin-cell rails typical in wearables. Built-in POR and software write protect safeguard against corruption during hot-plug charging events.
推荐
Industrial Module Identification and Parameter Retention
Industrial PLC I/O modules, smart sensors, and motor-drive boards often need to retain MAC IDs, firmware revision codes, and per-module calibration constants across power cycles. The 24CW640T-I/CS1668 with -40C to +85C industrial temperature rating operates reliably in factory cabinets, outdoor enclosures, and near heat-generating power devices. Its hardware WP pin allows the host to lock configuration pages during production programming, while the software write-protection bits can selectively allow end-user field updates. The 1 MHz I2C bus keeps programming time under 80 ms even for a full 8-Kbyte write burst, minimising line-downtime during commissioning.
推荐
Medical Wearable Identification and Logging
Medical wearables such as continuous-glucose monitors, ECG patches, and pill-dispenser modules require persistent, low-power, compact storage for patient ID, prescription parameters, and short-term event logs. The 24CW640T-I/CS1668 fits this role with its 8 Kbyte byte-erasable EEPROM, allowing fine-grained updates without the page-erase overhead of Flash. The wide 1.8 V to 5.5 V supply range supports single-cell alkaline, Li-ion, and energy-harvester designs common in medical devices. CSP package plus industrial temperature rating lets designers place it directly next to the analog front-end without thermal concerns.
推荐
Consumer Device White-Balance and RF Calibration
Cameras, displays, and RF modules need per-unit factory calibration data to correct for component tolerances. The 24CW640T-I/CS1668 stores white-balance gains, gamma LUT offsets, antenna-matching values, and transmit-power trim values for Bluetooth/WiFi radios. With 8 Kbytes organised as 8192 x 8 bits, the part can hold multiple profile sets and revision history. Its 1 MHz I2C speed allows fast parallel programming during end-of-line testing, while the built-in noise suppression on SDA/SCL reduces EMI-induced bit errors in noisy factory environments.
推荐
Smart Card / NFC Tag Pairing Data Storage
The 24CW640T-I/CS1668 is suitable as a secondary non-volatile store for NFC / RFID pairing records, secure tokens, and short audit logs in access-control and payment terminals. Its 64-byte page write buffer allows fast batch updates of credential databases, while software write protection prevents unauthorised in-field modification of security-critical blocks. The 4-CSP package integrates easily into the slimmest smart-card and key-fob form factors, and 1.8 V operation is fully compatible with NFC front-end ICs that harvest power from the reader field.
推荐
推荐产品汇总
工程参考数据： 24CW640T-I/CS1668 ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | 24CW640T-I/CS0668 | 24CW640T-I/OT |
|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 4-CSP (4-XFBGA, CSPBGA) | 4-CSP (same) | SOT-23-6 (different) |
| Memory Size | 64 Kbit (8K x 8) | 64 Kbit (8K x 8) | 64 Kbit (8K x 8) |
| Interface | I2C, 1 MHz | I2C, 1 MHz | I2C, 1 MHz |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| Access Time | 450 ns | 450 ns | 450 ns |
| Built-in POR / SWP | Yes / Yes | Yes / Yes | Yes / Yes |
关键差异点
- Smallest footprint in the 24CW640 family at under 1 mm x 1 mm （对比 24CW640T-I/OT (SOT-23-6))
- 1 MHz Fast-Plus I2C clock, 2.5x faster than legacy 400 kHz Fast mode （对比 24AA64 / 24FC64 series (400 kHz))
- Single-supply 1.8 V to 5.5 V operation with built-in noise suppression （对比 Generic 24C-series EEPROMs)
设计说明
The 4-CSP package uses NSMD (non-solder-mask-defined) pads and a 4-ball land pattern. Recommended pad diameter is approximately 0.25 mm with 0.4 mm pitch; route SDA/SCL as short impedance-controlled traces (typically 50 ohm with 4 mA driver strength) and place I2C pull-ups (2.2 kohm to 10 kohm depending on bus capacitance) close to the host MCU. Avoid routing SDA/SCL directly under noisy power inductors or near the antenna keep-out region.
WLCSP devices are moisture-sensitive. Although most 24CW640 CSP variants are rated MSL-1, treat them per JEDEC J-STD-033 if the dry-pack bag has been open beyond the floor-life limit. Avoid hand-soldering the CSP; use a reflow profile with peak temperature below 250C and ensure the solder paste stencil aperture matches the recommended 0.25 mm pad geometry to prevent solder-ball bridging.
I2C bus rise time is governed by pull-up resistor and bus capacitance. For 1 MHz Fast-Plus mode, keep total bus capacitance below 100 pF and use a stronger pull-up (2.2 kohm at 3.3 V, 1.8 kohm at 1.8 V) to maintain the 300 ns rise-time spec of Fast-Plus. The 24CW640's built-in Schmitt-trigger and noise-suppression filter provide ~50 ns glitch rejection on SDA/SCL, but very noisy environments still benefit from a small RC filter on each line.
The 24CW640T-I/CS1668 typical standby current is below 1 uA at 3.3 V, and active read current is under 1 mA, making it suitable for battery-powered designs. During a write cycle the chip enters an internal timer state with supply current around 1 mA to 3 mA; the host should poll the device with ACK polling rather than wait a fixed 5 ms delay, which both saves energy and speeds up bulk programming by up to 4x compared with legacy fixed-delay algorithms.
合规信息
RoHS compliant per Microchip product page. Industrial temperature grade (-40C to +85C). AEC-Q100 not applicable - this is a general-purpose EEPROM, not an automotive-qualified part. Halogen-free status not stated in verified web data; flagged as unknown.
