MC68HC908JB8JP - 8KB Flash 8-bit USB MCU 20-DIP | NXP
料号： MC68HC908JB8JP ✗ 停产| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $8.9 | $8.90 |
| 10 | $7.65 | $76.50 |
| 100 | $6.2 | $620.00 |
| 500 | $5.1 | $2,550.00 |
| 1,000 | $4.25 | $4,250.00 |
MC68HC908JB8JP 概述
What is an HC08 microcontroller? The HC08 is NXP/Freescale's 8-bit CISC microcontroller architecture derived from the original Motorola 6800. It uses a von Neumann unified memory map where program Flash, data RAM, and I/O registers share the same 16-bit address space (up to 64KB). HC08 parts are characterized by aggressive low-power design, Flash-based program storage for in-circuit reprogrammability, and a modular peripheral set that scales from small 8-pin controllers to USB-capable 20-pin devices like the JB8 family.
The MC68HC908JB8JP runs the enhanced M68HC08 CPU at up to 3MHz internal bus rate from an external crystal or resonator, executing most instructions in 2 to 5 bus cycles. Its integrated USB 1.1 low-speed interface includes a 3.3V regulator, 1.5kohm pull-up resistor, and dedicated endpoint buffers (256 bytes of USB RAM), making it one of the lowest-cost ways to add USB device functionality to embedded designs without an external PHY.
Typical applications include low-cost USB peripherals such as computer mouse/keyboard dongles, optical mice, game controllers, remote keyless entry (RKE) transmitters with USB programming, barcode scanners, and point-of-sale (POS) accessories. The 8KB Flash accommodates CDC, HID, or vendor-class USB firmware stacks with margin for bootloaders and product customization.
When designing with the MC68HC908JB8JP, observe USB suspend current limits (typically under 500uA device-side), place the 4MHz crystal close to the OSC pins with short traces, and provide proper USB bus-powered decoupling. The 20-pin PDIP package suits breadboarding, prototype development, and through-hole field-installed products but is not recommended for high-volume surface-mount assembly, where the SOIC-20 variant is preferred.
直接替换替代料： MC68HC908JB8JP ——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：
MC68HC908JB8JW
✅ 直接替换📋 参考替代料（不在目录中）
MC68HC908JB16JP
✅ 直接替换📋 参考替代料（不在目录中）
MC68HC908JT8JP
✅ 直接替换📋 参考替代料（不在目录中）
MC68HC08JB8JP
✅ 直接替换📋 参考替代料（不在目录中）
MC9S08JS08CWJ
✅ 直接替换📋 参考替代料（不在目录中）
MC68HC908JB8JP 最大额定值与电气特性
| Core Architecture | M68HC08 (8-bit CISC) |
| Program Memory | 8KB (8K x 8) Flash |
| CPU Frequency | 3 MHz (internal bus) |
| USB Interface | USB 1.1 low-speed device, integrated transceiver |
| 封装 | 20-pin PDIP (Plastic DIP, through-hole) |
| 安装类型 | Through-Hole (THT) |
| MSL 等级 | 1 (not moisture sensitive for PDIP) |
| Series | M68HC08 |
| On-chip Regulator | 3.3V USB transceiver regulator |
MC68HC908JB8JP 引脚配置
| 引脚 1 | IRQ — External interrupt request input |
| 引脚 2 | RST — Reset input (active low) |
| 引脚 3 | PTA0 — Port A bit 0 (general I/O) |
| 引脚 4 | PTA1 — Port A bit 1 (general I/O) |
| 引脚 5 | PTA2 — Port A bit 2 (general I/O) |
| 引脚 6 | PTA3 — Port A bit 3 (general I/O) |
| 引脚 7 | VDD — Power supply (+5V typical) |
| 引脚 8 | VSS — Ground reference |
| 引脚 9 | OSC1 — Crystal oscillator input |
| 引脚 10 | OSC2 — Crystal oscillator output |
| 引脚 11 | D+ — USB D+ data line (with internal pull-up) |
| 引脚 12 | D- — USB D- data line |
| 引脚 13 | PTC0 — Port C bit 0 (general I/O) |
| 引脚 14 | PTC1 — Port C bit 1 (general I/O) |
| 引脚 15 | PTC2 — Port C bit 2 (general I/O) |
| 引脚 16 | PTC3 — Port C bit 3 (general I/O) |
| 引脚 17 | PTC4 — Port C bit 4 (general I/O) |
| 引脚 18 | PTC5 — Port C bit 5 (general I/O) |
| 引脚 19 | PTB0/TxD — Port B bit 0 / SCI transmit |
| 引脚 20 | PTB1/RxD — Port B bit 1 / SCI receive |
典型应用
MC68HC908JB8JP 适用于 6 应用s: USB Mouse / Keyboard HID Device, Wired Barcode Scanner / POS Accessory, Optical Mouse with USB Interface, Remote Keyless Entry (RKE) USB Programmer, USB Game Controller (Joystick / Gamepad), USB-to-Serial / USB-to-I2C Bridge Dongle.
USB Mouse / Keyboard HID Device
The MC68HC908JB8JP is purpose-built for low-cost USB Human Interface Devices because its integrated USB 1.1 low-speed transceiver eliminates external PHY cost, and its 3MHz HC08 core sustains HID polling rates of up to 1kHz. Place the part between the USB connector and the sensor matrix with 22 ohm series termination on D+/D- and a 4.7uF bulk cap on VBUS; the integrated 3.3V regulator powers internal logic and short cable links directly without external LDO. The 8KB Flash comfortably stores HID boot protocol firmware plus vendor customization, while the 256-byte USB RAM buffers endpoint packets without CPU intervention.
推荐
Wired Barcode Scanner / POS Accessory
For point-of-sale barcode scanners and HID-class point-of-sale accessories, the MC68HC908JB8JP's USB-integrated architecture is attractive: no external PHY means each scanner costs less than $5 in BOM, and the 20-pin PDIP supports through-hole assembly for ruggedized industrial enclosures. Drive the scan engine via GPIO at 5V tolerance from the VBUS rail, decode the CCD or laser pulse train in firmware, and forward as HID keyboard scan codes via USB interrupt endpoints. Unlike Bluetooth or Wi-Fi alternatives, the wired USB path requires no pairing steps and provides bus-powered operation with the integrated 3.3V regulator handling all internal rails.
推荐
Optical Mouse with USB Interface
The MC68HC908JB8JP's combination of 8KB Flash, 128-byte general RAM, and integrated USB low-speed transceiver targets optical and laser mice, where it interfaces with an external ADNS-style image sensor over SPI or GPIO at typical 1500-3000 DPI resolution. Sample the sensor at USB polling interval (typically 125Hz for mice), compute delta-X/delta-Y, and forward as HID mouse reports - entirely in firmware with no off-chip logic. The 5V-tolerant I/O tolerates direct connection to legacy 5V mouse pads and peripherals, while the small 20-DIP footprint suits compact ergonomic housings.
推荐
Remote Keyless Entry (RKE) USB Programmer
Although RKE transmitters themselves are often sub-1GHz RF MCUs, USB programming docks for RKE key fobs use the MC68HC908JB8JP as a low-cost firmware update channel: connect a docked RKE fob to the dock's USB port, run a vendor HID/DFU loader, and reprogram the fob's internal Flash via serial or one-wire handshake. The 8KB Flash in the dock holds a generic bootloader and a customizable VID/PID, while 256-byte USB RAM comfortably buffers DFU block transfers. Compared to dedicated SPI/I2C programmer dongles, this USB-HID approach requires no proprietary host driver - any modern OS recognizes the device as a generic HID and runs the loader through a CLI.
推荐
USB Game Controller (Joystick / Gamepad)
Low-speed USB joysticks and gamepads use the MC68HC908JB8JP because HID-class game controllers fit well within USB 1.1 low-speed bandwidth (1.5Mbps), and integrating 8 to 16 digital/analog buttons fits comfortably inside the 8KB firmware Flash. The MCU scans button matrix via GPIO interrupt-on-change, debounces in firmware (typically 5-10ms), and reports button states plus axis data as HID gamepad reports at the host's polling interval. The integrated USB pull-up and 3.3V regulator reduce external components compared to designs requiring an external ULPI/UTMI PHY, keeping per-unit cost low for consumer-grade controllers.
推荐
USB-to-Serial / USB-to-I2C Bridge Dongle
The MC68HC908JB8JP is frequently used in cost-sensitive USB-to-UART and USB-to-I2C bridge dongles, exposing CDC-ACM or vendor-class endpoints to the host while bit-banging serial (UART) or two-wire (I2C/SMBus) on the device side. The 8KB Flash holds the protocol converter plus a small command parser for EEPROM programming or sensor configuration, while the 128-byte general-purpose RAM buffers convert packets on the fly. Operating directly from VBUS at 5V eliminates the need for an external regulator on the input rail; the integrated 3.3V LDO powers on-chip logic with no extra components.
推荐
推荐产品汇总
工程参考数据： MC68HC908JB8JP ——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 | MC68HC908JB8JW | MC68HC908JB16JP | MC68HC908JT8JP | MC68HC08JB8JP | MC9S08JS08CWJ |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | PDIP-20 | SOIC-20 (wide body) - different footprint | PDIP-20 - same | PDIP-20 - same | PDIP-20 - same | PDIP-20 - same |
| Core Architecture | HC08 (8-bit) | HC08 (8-bit) | HC08 (8-bit) | HC08 (8-bit) | HC08 (8-bit, mask ROM) | S08 (8-bit, enhanced) |
| Program Memory | 8KB Flash | 8KB Flash | 16KB Flash (+100%) | 8KB Flash | 8KB ROM (no in-circuit reprogram) | 8KB Flash |
| USB Interface | USB 1.1 low-speed | USB 1.1 low-speed | USB 1.1 low-speed | USB 1.1 low-speed | USB 1.1 low-speed | USB 2.0 full-speed (improved bandwidth) |
| CPU Clock | 3 MHz | 3 MHz | 3 MHz | 3 MHz | 3 MHz | Up to 48 MHz (much higher throughput) |
| On-chip Regulator | 3.3V USB (yes) | 3.3V USB (yes) | 3.3V USB (yes) | 3.3V USB (yes) | 3.3V USB (yes) | 5V-to-3.3V (improved) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Last-time-buy / NRND |
| Approx. Unit Price (qty 1) | USD 8.90 | USD 9.50 | USD 10.50 | USD 9.20 | USD 7.80 (ROM, lower cost) | USD 6.40 |
关键差异点
- Integrated USB 1.1 low-speed transceiver with on-chip 3.3V regulator （对比 Discrete USB MCU + external PHY)
- 8KB Flash storage suitable for full USB HID/CDC stacks （对比 MC68HC908JB4JP (4KB Flash variant))
- 20-pin PDIP through-hole package for prototype/field assembly （对比 MC68HC908JB8JW (SOIC-20 wide body))
- M68HC08 CPU with low-power STOP/WAIT modes （对比 Earlier HC05 family parts)
设计说明
USB bus-powered operation requires that the entire MC68HC908JB8JP system draws less than 100mA in standard load and less than 500uA in USB suspend (per USB 2.0 spec). The integrated 3.3V regulator can source enough current for internal logic and a small external load of approximately 50mA, but for USB suspend compliance, put peripherals in a low-power state and gate any external regulator downstream of VBUS through a control GPIO. Place a 4.7uF bulk capacitor on VBUS near the connector and a 1uF decoupling cap on the VDD pin, both within 5mm of the IC.
For the USB D+/D- traces, use 90-ohm differential impedance matching with the characteristic impedance of a USB cable. Keep D+/D- length-matched to within 2mm and route them on the top layer over a continuous ground pour. The 4MHz crystal (or ceramic resonator) must be placed within 6mm of OSC1 (pin 9) and OSC2 (pin 10), with short direct traces and a guard ring tied to ground. Avoid routing USB signals under any switching power supply or clock traces - cross only at 90-degree angles if absolutely necessary.
When prototyping with the MC68HC908JB8JP, ensure the HC08 background debug mode (BDM) is accessible - typically PTA0/PTA1 are used for BKGD and RESET during in-circuit programming, so do not strap these as outputs on power-up. The internal USB pull-up on D+ is enabled by firmware after enumeration begins; pulling it up too early (e.g., before system clock is stable) can confuse the host into detecting a low-speed device on an unstable bus. For new designs prefer the MC9S08JS08CWJ successor which adds USB 2.0 full-speed support for higher bandwidth CDC applications.
Although USB 1.1 low-speed signals are not as demanding as USB 2.0 high-speed, place a 22-ohm series resistor on D+ and D- as close to the connector as possible to suppress reflections and cable-bounce transients. The internal pull-up on D+ is 1.5kohm nominal but may need adjustment via firmware register writes to meet USB-IF compliance. When designing a hub or compound device, dedicate separate ground return for USB and digital logic to avoid coupling switching noise into the bus - a split-plane with a single-point bridge under the connector achieves this without ground loops.
合规信息
RoHS/REACH/lead-free status not confirmed in retrieved data; the part is legacy Motorola/Freescale and pre-dates widespread RoHS reporting - confirm per specific lot/date code with distributor for production orders. AEC-Q100 is not applicable because this is a consumer-grade commercial-temperature 8-bit MCU, not an automotive part.
