DS1307N+ - 64x8 Serial I2C RTC, 56B NV SRAM, 8-DIP | Maxim
部品番号: DS1307N ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $2.39 | $2.39 |
| 10 | $2.15 | $21.50 |
| 100 | $1.82 | $182.00 |
| 500 | $1.54 | $770.00 |
| 1,000 | $1.29 | $1,290.00 |
DS1307N 概要
A real-time clock (RTC) is a dedicated integrated circuit that maintains wall-clock time independent of the system host MCU. RTCs sit at the bottom of the timekeeping hierarchy alongside timers and counters within the broader clock-and-timing semiconductor category. They typically combine a 32.768 kHz quartz reference, a binary-coded decimal (BCD) time register set, and an I2C/SPI host interface, and are usually paired with a backup battery so that time advances even when main system power is removed.
Key features include automatic power-fail switching to a backup battery on VCC drop, low-power operation that extends coin-cell lifetime, square-wave output programmable from 1 Hz to 32.768 kHz, and on-chip 56-byte NV SRAM that retains data on backup supply. The BCD time format simplifies host firmware because each digit is stored in a separate nibble, eliminating binary-to-decimal conversion.
Architecturally, the DS1307N+ uses an external 32.768 kHz crystal as its timebase, a precision divider chain, an I2C slave state machine operating at standard (100 kHz) and fast (400 kHz) modes, and a power-management block that switches the load between VCC and VBAT without losing time. Accuracy is governed entirely by the external crystal (typically +/-20 ppm), which sets the long-term walk time of the module over an entire scope.
Typical applications include Arduino/maker time-of-day logging, data loggers, point-of-sale terminals, industrial controllers with time-stamped events, and any embedded system that needs wall-clock time across power cycles. The wide 4.5-5.5 V supply aligns with 5 V-tolerant hosts and legacy logic rails.
When designing with this part, choose the external 32.768 kHz crystal carefully (12.5 pF load capacitance recommended) and place it close to the X1/X2 traces to minimize noise pickup. Decouple VCC with a 100 nF ceramic cap and place a small series resistor on the SQW/OUT pin to reduce EMI on long traces.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
ドロップイン代替品: DS1307N — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
クイック比較ツール — 並列比較する代替部品を選択:
DS1307+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
DS1307Z+
✅ ドロップイン✓ 在庫あり
価格はお問い合わせください
データシートを見る →MCP79410-I/P
✅ ドロップイン📋 参考代替品（カタログ未掲載）
DS1337+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MCP79400-I/P
✅ ドロップイン📋 参考代替品（カタログ未掲載）
DS1307N 仕様
| 機能 | Real-Time Clock (RTC) with 56 bytes NV SRAM |
| Time Format | HH:MM:SS (12/24 hr), YY-MM-DD-dd, BCD |
| Date Format | YY-MM-DD-dd |
| メモリサイズ | 64 x 8 (56 bytes user NV SRAM + 8 bytes RTC registers) |
| インターフェース | I2C, 2-Wire Serial |
| I2C Bus Frequency | 100 kHz (Standard) / 400 kHz (Fast-mode) |
| Supply Voltage (VCC) | 4.5 V to 5.5 V |
| Backup Battery Voltage (VBAT) | 2.0 V to 3.5 V (typ. 3 V coin cell) |
| Active Supply Current | 1.5 mA |
| Standby (Timekeeping) Current | 200 uA |
| Leap-Year Compensation | Valid up to year 2100 |
| Programmable Square-Wave Output | 1 Hz, 4.096 kHz, 8.192 kHz, 32.768 kHz |
| 動作温度 | 0C to +70C (commercial) |
| パッケージ | 8-DIP (PDIP-8, 0.300 inch / 7.62 mm) |
| 実装タイプ | Through-Hole |
| MSLレベル | 1 (unlimited floor life) |
DS1307N ピン構成
| ピン 1 | X1 — 32.768 kHz crystal input |
| ピン 2 | X2 — 32.768 kHz crystal output |
| ピン 3 | VBAT — Backup battery input (+3 V typical) |
| ピン 4 | GND — Ground |
| ピン 5 | SDA — I2C serial data (open-drain, pull-up to VCC) |
| ピン 6 | SCL — I2C serial clock (open-drain, pull-up to VCC) |
| ピン 7 | SQW/OUT — Square-wave / output driver |
| ピン 8 | VCC — Main supply, 4.5 V to 5.5 V |
主な用途
DS1307N の用途: 6 件s: Arduino / Maker RTC Shield, Data Logger with Timestamped Events, Point-of-Sale Terminal Clock, Industrial Controller Time-Stamping, Vending Machine Audit Logging, HVAC Schedule Controller.
Arduino / Maker RTC Shield
The DS1307N+ is the original timekeeping chip behind the classic Arduino RTC module and Sparkfun DeadOn RTC breakout. Its 4.5-5.5 V supply aligns with Arduino's 5 V rail, the I2C interface works with the Wire library out of the box at address 0x68, and the 8-DIP package fits the common through-hole module footprint. The 56 bytes of NV SRAM let makers store calibration constants that persist when the project is unplugged.
おすすめ
Data Logger with Timestamped Events
Industrial data loggers need wall-clock time stamped onto every measurement, and the DS1307N+ provides BCD-formatted seconds-through-year data via I2C at 100/400 kHz. The 200 uA standby current lets a CR2032 keep current backing up the 56B SRAM for years between battery swaps. Designers can drop the 8-DIP part onto a custom logger PCB and pair it with a host MCU for low-cost field data logging applications.
おすすめ
Point-of-Sale Terminal Clock
POS terminals require accurate transaction timestamps for audit trails and end-of-day reconciliation. The DS1307N+ tracks date, time, and day-of-week across power cycles via its CR2032 backup, while the 56B NV SRAM holds configuration such as tax rates or terminal IDs that must persist through mains brownouts. The programmable 1 Hz / 4.096 kHz / 8.192 kHz / 32.768 kHz square-wave output can drive a piezo buzzer or status LED directly.
おすすめ
Industrial Controller Time-Stamping
Industrial PLCs and motor controllers log fault times for diagnostics, and the DS1307N+ provides a low-cost I2C wall-clock with battery backup. The 8-DIP package is field-replaceable without hot-air rework, simplifying service operations in legacy 24 V DIN-rail systems. The 4.5-5.5 V VCC range accepts the regulated 5 V rail inside typical PLC enclosures, and the 200 uA timekeeping current extends CR2032 service life to 5+ years.
おすすめ
Vending Machine Audit Logging
Vending machines log each dispense event for cash reconciliation and remote telemetry, and the DS1307N+ provides reliable wall-clock time even during multi-day power outages. The 56B NV SRAM holds transaction counts and last-vend timestamps, while the I2C bus shares nicely with EEPROM and host MCU. The through-hole 8-DIP package is rugged for the vibration and thermal cycling of vending cabinets.
おすすめ
HVAC Schedule Controller
HVAC thermostats and building controllers run time-based schedules for setpoint changes and unoccupied overrides. The DS1307N+ provides the wall-clock with battery backup across power cycles, and the SQW/OUT pin drives a 1 Hz interrupt to schedule RTC wake-up on the host MCU. The wide 4.5-5.5 V supply matches 24 VAC thermostated rails when rectified, and the 0-70 C commercial range suits indoor climate-controlled enclosures.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: DS1307N — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | DS1307+ | DS1307Z+ | MCP79410-I/P | DS1337+ | MCP79400-I/P |
|---|---|---|---|---|---|---|
| Package | 8-DIP (PDIP-8, 0.300 inch) | 8-DIP (PDIP-8) - identical | SOIC-8 surface-mount | 8-DIP (PDIP-8) - identical | 8-DIP (PDIP-8) - identical | 8-DIP (PDIP-8) - identical |
| Brand | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Microchip Technology | Analog Devices / Maxim Integrated | Microchip Technology |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Backup Battery Input | 2.0 V to 3.5 V VBAT | 2.0 V to 3.5 V VBAT | 2.0 V to 3.5 V VBAT | Integrated, no external VBAT | No VBAT pin | Integrated, no external VBAT |
| Active Supply Current | 1.5 mA | 1.5 mA | 1.5 mA | 1.2 mA typical | 0.6 mA typical | 1.2 mA typical |
| Standby Timekeeping Current | 200 uA | 200 uA | 200 uA | 1.2 uA (with internal battery switch) | 0.9 uA typical | 1.2 uA (with internal battery switch) |
| I2C Address | 0x68 | 0x68 | 0x68 | 0x68 | 0x68 | 0x68 |
| NV SRAM | 56 bytes | 56 bytes | 56 bytes | 64 bytes SRAM | None (registers only) | 64 bytes SRAM |
| Square-Wave Output | 1 Hz, 4.096 kHz, 8.192 kHz, 32.768 kHz | Same four frequencies | Same four frequencies | 1 Hz, 4.096 kHz, 8.192 kHz, 32.768 kHz | Programmable 1 Hz to 32.768 kHz | 1 Hz, 4.096 kHz, 8.192 kHz, 32.768 kHz |
| Accuracy (Crystal-Dependent) | External crystal +/-20 ppm typical | External crystal +/-20 ppm typical | External crystal +/-20 ppm typical | External crystal +/-20 ppm typical | External crystal +/-20 ppm typical | External crystal +/-20 ppm typical |
主な差別化要因
- Open-source firmware ecosystem （vs MCP79410-I/P)
- Wide 4.5-5.5 V main supply （vs DS1337+)
- Integrated battery-backed 56 B SRAM （vs DS1337+)
- Through-hole 8-DIP mechanical option （vs DS1307Z+)
設計ノート
Place the 32.768 kHz crystal within 1 cm of the X1/X2 pins and route the X1/X2 traces in parallel with each other to balance parasitic capacitance. Per Maxim application note guidance, keep digital signal traces (SCL/SDA) at least 2 mm away from the crystal traces to avoid coupling noise into the Pierce oscillator. Add a ground guard trace under the crystal to further reduce EMI susceptibility on power rails.
Decouple VCC (Pin 8) with a 100 nF ceramic capacitor placed within 5 mm of the pin, and add a 10 uF bulk capacitor nearby to handle inrush during VBAT-to-VCC switchover. Place a 1 uF decoupling capacitor on VBAT (Pin 3) with the +' side to BJT_PMOS drain. Per the Maxim datasheet, when VCC drops below 1.25 x VBAT the IC switches the load to VBAT; ensure your VCC ramp-down slope is faster than 30 us to avoid glitches.
SDA (Pin 5) and SCL (Pin 6) are open-drain and MUST be pulled up to VCC with 4.7 kohm resistors for Standard-mode 100 kHz I2C, or 2.2 kohm for Fast-mode 400 kHz. Per the I2C spec, leaving the lines floating causes the host to read indeterminate logic levels and the DS1307RTC will not respond on address 0x68. Also: do not connect the SQW/OUT pin (Pin 7) to VCC directly - it is an open-drain output that requires a pull-up if used.
When routing SDA and SCL on a long bus (over 10 cm), add a small ferrite in the VCC line near the DS1307N+ to filter switching noise from the I2C pull-ups. The I2C lines have ~50 pF per meter of capacitance; a 1 MHz square wave on a long cable can degrade the rise time and cause ACK failures at 400 kHz Fast-mode. For multi-master buses, the SQW/OUT pin can be used as a hardware sync reference.
コンプライアンス情報
DS1307N+ (with '+' suffix) is supplied in lead-free matte-tin finish per Maxim Integrated/Analog Devices product page. RoHS/REACH compliance confirmed by Analog Devices product documentation as of 2026. AEC-Q100 not applicable (commercial Grade only - operating temperature 0 C to +70 C).
