MC68HC908BD48IB - 8-bit HC08 MCU 48KB Flash USB | NXP
MPN: MC68HC908BD48IB ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.54 | $6.54 |
| 10 | $5.89 | $58.90 |
| 100 | $5.24 | $524.00 |
| 500 | $4.68 | $2,340.00 |
| 1,000 | $4.15 | $4,150.00 |
MC68HC908BD48IB Overview
An HC08 microcontroller is a member of the 8-bit microcontrollers category, which falls under the broader hierarchy of microcontrollers -> microprocessors -> processors -> semiconductor devices -> integrated circuits. The HC08 architecture uses a von-Neumann memory map with a HCMOS process technology and is the predecessor of the enhanced HCS08 family, sharing the same instruction set for software portability. Within NXP's (formerly Motorola/Freescale) 8-bit roadmap, the MC68HC908BD48 belongs to the BD-series, which is specifically optimized for USB-enabled peripherals such as keyboards, mice, game pads, and pointer devices.
Key differentiating features of the MC68HC908BD48IB include on-chip USB 1.0 low-speed transceiver compliant with the Universal Serial Bus specification, a 6-channel 8-bit ADC for analog sensing, a 16-channel 8-bit PWM for motor control or LED dimming, and an internal oscillator that reduces external component count. The device integrates 32 general-purpose I/O pins and includes a 42-pin SDIP through-hole package for robust prototyping and field-replaceable modules.
The architecture combines an 8-bit HC08 CPU, security features to lock Flash memory against unauthorized reads, and a low-power STOP/WAIT mode for battery-aware USB peripherals. The integrated USB PHY eliminates the external transceiver typically required for low-speed USB on other 8-bit MCUs, reducing BOM cost and PCB area while maintaining full USB 1.0 compliance.
Typical applications include USB keyboards, USB mice and pointing devices, USB game pads and joysticks, USB barcode scanners, and low-speed USB industrial input devices. The integrated ADC and PWM allow the same MCU to drive both analog sensors and actuators alongside the USB interface.
When designing with the MC68HC908BD48IB, ensure proper USB bus-power decoupling (per USB 1.0 specification) and respect the 5V VCC tolerance of the USB D+/D- pins. The internal oscillator eliminates an external crystal for USB-synchronized applications, simplifying the BOM and reducing the PCB footprint compared to crystal-driven alternatives.
This page synthesizes distributor pricing, drop-in same-package alternatives, and design considerations not found in the manufacturer datasheet to help engineers evaluate this legacy USB 8-bit MCU for both new designs and field replacements.
Drop-in alternatives for MC68HC908BD48IB — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC68HC908BD24IB
✅ Drop-In📋 Reference alternative (not in catalog)
MC68HC908BD32IB
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908BD48CFU
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908JB8JDW
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908BD48IB Maximum Ratings & Electrical Characteristics
| Core Architecture | HC08 (8-bit HCMOS) |
| Program Memory Size | 48 KB (48K x 8) Flash |
| RAM Size | 1 KB (1K x 8) |
| Maximum Clock Frequency | 6 MHz internal bus |
| Number of I/O Pins | 32 |
| ADC | 6-channel, 8-bit |
| PWM | 16-channel, 8-bit |
| USB Interface | USB 1.0 low-speed, 3 endpoints |
| Oscillator Type | Internal |
| Package / Case | 42-SDIP (0.600", 15.24 mm) |
| Mounting Type | Through-Hole |
| Packaging | Tube |
| RoHS Status | unknown |
MC68HC908BD48IB Pin Configuration
| Pin 1 | PTA0 — Port A bit 0 (general-purpose I/O) |
| Pin 2 | PTA1 — Port A bit 1 (general-purpose I/O) |
| Pin 3 | PTA2 — Port A bit 2 (general-purpose I/O) |
| Pin 4 | PTA3 — Port A bit 3 (general-purpose I/O) |
| Pin 5 | PTA4 — Port A bit 4 (general-purpose I/O) |
| Pin 6 | PTA5 — Port A bit 5 (general-purpose I/O) |
| Pin 7 | PTA6 — Port A bit 6 (general-purpose I/O) |
| Pin 8 | PTA7 — Port A bit 7 (general-purpose I/O) |
| Pin 9 | VSS — Ground |
| Pin 10 | VDD — Positive supply |
| Pin 11 | PTB0 — Port B bit 0 / ADC channel |
| Pin 12 | PTB1 — Port B bit 1 / ADC channel |
| Pin 13 | PTB2 — Port B bit 2 / ADC channel |
| Pin 14 | PTB3 — Port B bit 3 / ADC channel |
| Pin 15 | PTB4 — Port B bit 4 / ADC channel |
| Pin 16 | PTB5 — Port B bit 5 / ADC channel |
| Pin 17 | PTB6 — Port B bit 6 |
| Pin 18 | PTB7 — Port B bit 7 |
| Pin 19 | PTC0 — Port C bit 0 / PWM channel |
| Pin 20 | PTC1 — Port C bit 1 / PWM channel |
| Pin 21 | PTC2 — Port C bit 2 / PWM channel |
| Pin 22 | PTC3 — Port C bit 3 / PWM channel |
| Pin 23 | PTC4 — Port C bit 4 / PWM channel |
| Pin 24 | PTC5 — Port C bit 5 / PWM channel |
| Pin 25 | PTC6 — Port C bit 6 / PWM channel |
| Pin 26 | PTC7 — Port C bit 7 / PWM channel |
| Pin 27 | PTD0 — Port D bit 0 / PWM channel |
| Pin 28 | PTD1 — Port D bit 1 / PWM channel |
| Pin 29 | PTD2 — Port D bit 2 / PWM channel |
| Pin 30 | PTD3 — Port D bit 3 / PWM channel |
| Pin 31 | PTD4 — Port D bit 4 / PWM channel |
| Pin 32 | PTD5 — Port D bit 5 / PWM channel |
| Pin 33 | PTD6 — Port D bit 6 / PWM channel |
| Pin 34 | PTD7 — Port D bit 7 / PWM channel |
| Pin 35 | D- — USB Data Minus (low-speed) |
| Pin 36 | D+ — USB Data Plus (low-speed) |
| Pin 37 | VUSB — USB 3.3V regulator output |
| Pin 38 | RST — Reset input (active low) |
| Pin 39 | IRQ — External interrupt request |
| Pin 40 | OSC1 — Crystal/oscillator input (internal osc bypassed) |
| Pin 41 | OSC2 — Crystal/oscillator output |
| Pin 42 | VPP — Programming voltage for Flash |
Typical Applications
MC68HC908BD48IB is suitable for 6 applications: USB Keyboard, USB Mouse and Pointing Device, USB Game Pad / Joystick, USB Barcode Scanner, Industrial USB Input Device, USB-Based Security Token / Dongle.
USB Keyboard
The MC68HC908BD48IB drives a full-feature USB keyboard with multimedia and macro keys, where its 48KB Flash holds HID report descriptors, scan matrices, and multilingual lookup tables while the integrated USB 1.0 low-speed transceiver with three endpoints handles Boot and Report protocols natively. The 1KB RAM buffers keystroke events without external memory, the 6-channel 8-bit ADC supports backlight brightness or battery monitoring on wireless variants, and the 16-channel 8-bit PWM drives per-key LED indicators. Placed as the sole controller between the USB D+/D- pins and the key-matrix scan lines, it eliminates an external transceiver and reduces BOM cost versus two-chip USB solutions. Trade-off: the 6 MHz internal bus caps the matrix scan rate, limiting ultra-high-polling-rate designs above 250 Hz.
Recommended
USB Mouse and Pointing Device
The MC68HC908BD48IB suits optical and ball-based USB mice where the 6-channel 8-bit ADC samples the IR-sensor quadrature signals, the 16-channel PWM drives the LED brightness control, and the USB 1.0 low-speed PHY reports relative X/Y motion via the integrated HID endpoints. Its 48KB Flash accommodates customizable button mappings and DPI profiles, while the 32 GPIO pins connect directly to scroll-wheel quadrature, button matrices, and status LEDs without external logic. The internal oscillator eliminates an external crystal, shrinking the PCB for compact travel mice. Trade-off: the 6 MHz core limits maximum report rate to ~125 Hz typical for low-speed USB HID, which is acceptable for office mice but tight for high-end gaming pointers.
Recommended
USB Game Pad / Joystick
For USB game pads and joysticks, the MC68HC908BD48IB offers 6-channel 8-bit ADC inputs that read potentiometer-based analog axes, while the 16-channel 8-bit PWM provides rumble-motor drive signals without extra timer peripherals. The 32 GPIO scan a 4x4 button matrix, and the on-chip USB 1.0 low-speed transceiver with three endpoints implements HID Gamepad-class reports (buttons, axes, hat-switch) directly. The 48KB Flash stores multiple game profiles and button-mapping firmware. Trade-off: the 6 MHz bus limits polling rate; for high-speed gaming (>500 Hz) consider USB full-speed HCS08 or S08 derivatives that share the same pinout philosophy but require a different package.
Recommended
USB Barcode Scanner
Handheld USB barcode scanners leverage the MC68HC908BD48IB's USB 1.0 low-speed HID-Keyboard interface to deliver scanned codes as keystrokes to the host PC. The 48KB Flash stores symbology-decoding firmware (Code 39, Code 128, UPC/EAN), the 6-channel ADC reads ambient-light and trigger sensors, and the 16 PWM channels drive the aiming laser or LED intensity. The 32 GPIO drive beeper, trigger switch, and LED indicators. Trade-off: low-speed USB caps throughput to ~1.5 Mbps effective; high-volume industrial scanners typically require full-speed USB.
Recommended
Industrial USB Input Device
Factory-floor USB input devices (operator keypads, panel-mount controllers) use the MC68HC908BD48IB for its robust 42-SDIP through-hole package that withstands vibration better than QFN alternatives. The 6-channel 8-bit ADC reads analog panel controls, the 16-channel PWM drives indicator lamps or buzzers, and the USB 1.0 low-speed PHY integrates cleanly with industrial PCs. The 48KB Flash supports long lifecycle firmware revisions. Trade-off: the part is NRND; new industrial designs should evaluate the S9S08SG8 for longevity even though it requires PCB rework.
Recommended
USB-Based Security Token / Dongle
Low-speed USB security tokens and software-protection dongles use the MC68HC908BD48IB's Flash lock feature to prevent unauthorized firmware reads while exposing HID commands to the host PC. The 48KB Flash stores cryptographic challenge-response routines, the 6-channel ADC verifies analog tamper sensors, and the 32 GPIO drive status LEDs. The 42-SDIP package supports field-replaceable modules for legacy installations. Trade-off: low-speed USB limits the data channel; modern tokens migrate to full-speed or USB 2.0 with different MCUs.
Recommended
Recommended Products Summary
Engineering reference data for MC68HC908BD48IB — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC68HC908BD24IB | MC68HC908BD32IB | MC68HC908BD48CFU | MC68HC908JB8JDW |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 42-SDIP | 42-SDIP - same | 42-SDIP - same | 42-SDIP - same | 42-SDIP - same |
| Flash Memory | 48 KB | 24 KB | 32 KB | 48 KB | 8 KB |
| RAM Size | 1 KB | 1 KB | 1 KB | 1 KB | 256 B |
| Core Clock | 6 MHz | 6 MHz | 6 MHz | 6 MHz | 6 MHz |
| USB Interface | USB 1.0 low-speed, 3 endpoints | USB 1.0 low-speed, 3 endpoints | USB 1.0 low-speed, 3 endpoints | USB 1.0 low-speed, 3 endpoints | USB 1.0 low-speed, 3 endpoints |
| ADC | 6-channel, 8-bit | 6-channel, 8-bit | 6-channel, 8-bit | 6-channel, 8-bit | 8-channel, 8-bit |
Key Differentiators
- Highest Flash in BD-series (48KB) (vs MC68HC908BD24IB)
- Larger Flash than JB-series (8KB) (vs MC68HC908JB8JDW)
- 32 GPIO vs fewer on competing HC08 parts (vs MC68HC908JB8JDW)
Design Notes
The MC68HC908BD48IB requires both a 5V VDD rail (for USB D+/D- I/O) and a regulated 3.3V rail derived from the internal VUSB regulator. Per the MC68HC908BD48 datasheet, place a 1uF decoupling capacitor on VDD and a 4.7uF bulk capacitor on VUSB within 5 mm of the pins; insufficient VUSB decoupling causes intermittent USB enumeration failures.
Do not omit the 1.5 kohm pull-up resistor on the D- line for low-speed USB enumeration - this is mandatory per USB 1.0 specification. Also confirm that the internal oscillator trim (OSC_TRIM in Flash $FFC0) is calibrated at 6 MHz bus; untrimmed parts report wrong baud rates over USB.
The 42-SDIP through-hole package leaves a 0.600" (15.24 mm) row spacing - use 0.8 mm or 1.0 mm drill holes with at least 0.6 mm annular ring for wave-solder reliability. Keep USB D+/D- traces matched in length (within 2 mm) and route them over a continuous ground plane to meet USB 1.0 signal-integrity limits.
At 6 MHz internal bus and typical 5V/15 mA active current, the MC68HC908BD48IB dissipates roughly 75 mW. The 42-SDIP package theta_JA of approximately 60 C/W yields a junction rise of only 4-5 C above ambient - no heatsink is required, but ensure the enclosure provides some airflow if the device is sealed inside a USB connector shell.
Compliance Information
Compliance status not stated in the verified distributor listings; consult NXP product page or PCN documentation for definitive RoHS/REACH information. Not AEC-Q100 qualified (industrial/consumer grade).
