BQ32000DR - Serial RTC with Battery Backup, I2C, 8-SOIC | Texas Instruments
料号： BQ32000DR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.95 | $1.95 |
| 10 | $1.72 | $17.20 |
| 100 | $1.41 | $141.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $0.98 | $980.00 |
BQ32000DR 概述
A real-time clock (RTC) is a low-power timing IC that maintains accurate wall-clock time (seconds, minutes, day, month, year) independently of the host MCU, allowing the system to keep time even when main power is removed. RTCs sit in the broader clock & timing hierarchy (RTC -> clock IC -> timing IC -> semiconductor) and are typically paired with a backup energy source such as a coin cell or supercapacitor to ride out power interruptions. The BQ32000DR's integrated trickle charger removes the need for an external charging circuit, simplifying the BOM while still supporting rechargeable backup sources.
Key specifications include I2C serial interface operation up to 400 kHz (Fast Mode), a programmable calibration range of -63 ppm to +126 ppm for crystal ageing compensation, automatic switchover to backup supply at a typical threshold of approximately 2.5 V, integrated oscillator-fail detection with OF flag, and an operating supply range of 3.0 V to 3.6 V. The 8-SOIC package footprint is industry standard, allowing drop-in replacement of legacy RTCs in many designs.
Architecturally, the BQ32000DR uses a bandgap reference, a divider chain from the 32.768 kHz crystal, BCD-format time/date counters, and an I2C slave controller. The automatic backup switchover compares VCC to the backup supply and seamlessly routes power to the RTC core, eliminating host-side timekeeping recovery on power-up.
Typical applications include smart electricity meters, industrial controllers, point-of-sale terminals, medical data recorders, and any embedded system that must retain wall-clock time across main-power loss. It also fits consumer electronics with battery-backed user clocks.
When designing with this device, ensure the crystal load capacitance matches the chosen 32.768 kHz crystal (typically 12.5 pF) and place both crystal traces close to the XIN/XOUT pins. Avoid routing noisy switching signals near the crystal to keep jitter and time drift low.
This page synthesizes distributor pricing, drop-in alternatives, and design notes not always consolidated in the manufacturer datasheet, giving engineers a single reference for evaluation and procurement.
直接替换替代料： BQ32000DR ——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：
BQ32002DR
✅ 直接替换📋 参考替代料（不在目录中）
BQ32000D
✅ 直接替换📋 参考替代料（不在目录中）
BQ32000DR-Q1
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
PCF8563T
✅ 直接替换📋 参考替代料（不在目录中）
DS1307+
✅ 直接替换📋 参考替代料（不在目录中）
MCP79410-I/SN
✅ 直接替换📋 参考替代料（不在目录中）
BQ32000DR 规格参数
| 功能 | Serial Real-Time Clock (RTC) with battery backup and trickle charger |
| Serial Interface | I2C, 2-wire, up to 400 kHz |
| Operating Supply Voltage (VCC) | 3.0 V to 3.6 V |
| Backup Supply Voltage | 1.3 V to 4.0 V (capacitor or non-rechargeable battery) |
| Crystal Frequency | 32.768 kHz |
| Calibration Adjustment Range | -63 ppm to +126 ppm (programmable) |
| Time Format | HH:MM:SS, day-of-week, day, month, year (BCD) |
| Oscillator-Fail Detection | Yes (OF flag in status register) |
| Backup Switchover | Automatic, integrated trickle charger |
| 工作温度范围 | -40 C to +85 C |
| 封装 | 8-SOIC (3.90 mm / 0.154 in body width) |
| 安装类型 | Surface Mount |
| MSL 等级 | 1 (per PartGenie summary) |
| RoHS 状态 | Compliant (Yes) |
BQ32000DR 引脚配置
| 引脚 1 | XIN — 32.768 kHz crystal input |
| 引脚 2 | XOUT — 32.768 kHz crystal output |
| 引脚 3 | VBACKUP — Backup supply input (capacitor or non-rechargeable battery) |
| 引脚 4 | GND — Ground |
| 引脚 5 | SDA — I2C serial data |
| 引脚 6 | SCL — I2C serial clock |
| 引脚 7 | IRQ — Interrupt output (open-drain) |
| 引脚 8 | VCC — Main supply (3.0 V to 3.6 V) |
典型应用
BQ32000DR 适用于 6 应用s: Smart Electricity Meter Timekeeping, Industrial PLC and Controller RTC, Point-of-Sale Terminal Time Stamping, Medical Data Recorder Time Stamp, Automotive Infotainment Clock, Consumer Electronics Wall-Clock Backup.
Smart Electricity Meter Timekeeping
The BQ32000DR's integrated trickle charger and automatic backup switchover make it ideal for smart electricity meters that must retain wall-clock time and tariff schedules through power outages. Its 3.0-3.6 V main supply and 1.3-4.0 V backup range accept a 3 V coin cell directly, while the OF (oscillator-fail) flag lets the host MCU detect a degraded 32.768 kHz crystal before timekeeping accuracy is lost. I2C at 400 kHz lets the meter MCU poll the RTC quickly during metrology cycles, and the -63 to +126 ppm calibration range corrects for crystal ageing across the meter's 15-20 year service life, ensuring regulatory-compliant time stamps on billing data.
推荐
Industrial PLC and Controller RTC
In industrial PLCs and process controllers the BQ32000DR provides a battery-backed wall clock for event timestamping, scheduled-task triggers, and audit-log entries that must survive controller power cycles. Its -40 C to +85 C operating range covers most factory-floor environments, and the 8-SOIC footprint mounts easily alongside the host MCU on the backplane. The OF flag supports preventive maintenance by alerting when the crystal is failing, and I2C up to 400 kHz minimizes the MCU's RTC access time, leaving more CPU bandwidth for control loops. The integrated trickle charger also removes the need for an external backup-supply circuit, reducing BOM cost.
推荐
Point-of-Sale Terminal Time Stamping
POS terminals need accurate wall-clock time on every receipt and transaction log, and the BQ32000DR delivers this through its automatic backup switchover, which keeps time running even if the main supply is unplugged or fails during a transaction. The I2C 400 kHz interface allows the terminal's application processor to read time in under a millisecond, and the calibration register compensates for crystal drift in fluctuating retail-temperature environments. The 8-SOIC package sits compactly on the terminal main board, and the integrated trickle charger supports a small supercapacitor backup that recharges during normal operation, avoiding coin-cell replacement in deployed terminals.
推荐
Medical Data Recorder Time Stamp
Medical devices such as ambulatory recorders, patient wearables, and clinical instruments must timestamp every sample with regulatory traceability, and the BQ32000DR supports this with its wide -40 C to +85 C operating range and battery-backed timekeeping. The OF flag alerts the host when the 32.768 kHz crystal is degraded, so medical firmware can flag data integrity before storage, and the integrated trickle charger lets the device run from a rechargeable backup cell for portable use. The I2C interface gives the recorder's MCU low-overhead time reads during high-frequency sampling, minimizing timing jitter in measurement windows.
推荐
Automotive Infotainment Clock
For automotive infotainment systems and dashboard clocks, the BQ32000DR-Q1 (AEC-Q100 qualified variant) provides robust wall-clock time across cranking transients and battery disconnects. The integrated trickle charger can be configured to maintain a backup supercapacitor so the clock resumes within seconds of a battery reconnect, and the -63 to +126 ppm calibration compensates for the wide automotive temperature range. I2C at 400 kHz lets the infotainment host query time quickly during CAN wake-up, and the 8-SOIC package fits the typical 2-layer automotive PCB. The OF flag supports diagnostics during factory end-of-line test.
推荐
Consumer Electronics Wall-Clock Backup
Consumer products such as digital photo frames, smart speakers, and kitchen appliances use the BQ32000DR to retain clock and timer settings across power loss, eliminating user frustration with re-setting time after unplugging the device. The 3.0-3.6 V main supply is compatible with common 3.3 V system rails, and the integrated backup switchover with trickle charger lets designers use a small supercapacitor instead of a coin-cell for thinner product enclosures. The I2C 400 kHz interface minimizes read latency on power-up, and the 8-SOIC package keeps the RTC footprint under 30 mm^2, leaving more board area for the user-interface electronics.
推荐
推荐产品汇总
工程参考数据： BQ32000DR ——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 | BQ32002DR | BQ32000D | PCF8563T | DS1307+ | MCP79410-I/SN |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | NXP Semiconductors | Analog Devices | Microchip Technology |
| Package | 8-SOIC (3.90 mm) | 8-SOIC (3.90 mm) - same | 8-SOIC (3.90 mm) - same | 8-SOIC (3.90 mm) - same | 8-SOIC (3.90 mm) - same | 8-SOIC (3.90 mm) - same |
| Interface Speed | I2C up to 400 kHz | I2C up to 400 kHz | I2C up to 400 kHz | I2C up to 400 kHz | I2C up to 100 kHz | I2C up to 400 kHz |
| VCC Range | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 1.0 V to 5.5 V (wider) | 4.5 V to 5.5 V | 1.8 V to 5.5 V (wider) |
| Integrated Trickle Charger | Yes | Yes | Yes | No | No | Yes |
| Oscillator-Fail (OF) Flag | Yes | Yes | Yes | No | No | Yes (with power-fail flag) |
| Calibration Range | -63 ppm to +126 ppm | -63 ppm to +126 ppm | -63 ppm to +126 ppm | Capacitance-trim only | None | -127 ppm to +127 ppm |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | 0 C to +70 C (commercial) | -40 C to +85 C |
关键差异点
- Higher I2C bus speed (4x faster than DS1307) （对比 DS1307+)
- Integrated trickle charger with backup switchover （对比 PCF8563T)
- On-chip calibration and OF flag for diagnostics （对比 DS1307+)
设计说明
When laying out the BQ32000DR, keep the 32.768 kHz crystal traces short and symmetrical, and place the crystal within 5 mm of the XIN/XOUT pins to minimize parasitic capacitance. Avoid routing noisy switching signals (DC-DC SW nodes, MCU clock traces) under or near the crystal, as injected noise will appear as timekeeping jitter or drift. Use a crystal with 12.5 pF load capacitance (or adjust the on-chip load caps via the calibration register) and guard the crystal with a grounded copper pour to isolate it from board-level thermal gradients.
Estimated backup endurance for a CR2032 (220 mAh) at the BQ32000DR's typical 1.0 uA backup current (from TI datasheet family characteristics) is approximately 25 years at room temperature. For supercapacitor backup (0.1 F, 3.3 V), backup time at the same current is approximately 30-40 hours before VBACKUP falls below the 1.3 V cutoff - sufficient for most mains-blink ride-through. Enable the internal trickle charger with the appropriate series resistor per TI's BQ32000 datasheet to limit charging current into the backup source, and never charge a primary (non-rechargeable) lithium cell.
Add a 0.1 uF decoupling capacitor as close as possible to the VCC pin (pin 8) and a 10-100 nF capacitor on VBACKUP (pin 3) to suppress transient noise during switchover events. Pull-ups on SDA (pin 5) and SCL (pin 6) should be sized to the I2C bus capacitance - typical values are 4.7 kohm at 400 kHz on a short bus. The IRQ pin (pin 7) is open-drain and requires an external pull-up; if unused, leave it floating or tied to GND through 100 kohm to prevent false triggering.
合规信息
RoHS compliant per PartGenie summary. Automotive qualification available on BQ32000DR-Q1 variant. REACH and halogen-free status should be confirmed with TI's latest material declaration.
