EFM8UB20F64G-A-QFP48 - 8-bit USB MCU, 64kB Flash | Silicon Labs
MPN: EFM8UB20F64G-A-QFP48 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.78 | $278.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.18 | $2,180.00 |
EFM8UB20F64G-A-QFP48 Overview
An 8-bit microcontroller (MCU) is a microprocessor integrated on a single IC with program memory (Flash), data memory (RAM), and peripheral interfaces. The 8051 architecture, originally introduced by Intel in 1980, remains widely used in cost-sensitive embedded applications. The CIP-51 core used by Silicon Labs is a pipelined 8051 implementation that executes most instructions in 1-2 system clocks, delivering roughly 10x the throughput of a standard 8051 at the same clock. The EFM8UB20F64G-A-QFP48 belongs to the universal-bee sub-family, which adds USB 2.0 full-speed support and analog peripherals aimed at USB human-interface and communication devices.
Key features include 40 digital I/O pins, 6 x 16-bit timers, 5 programmable counter array (PCA) channels, a 10-bit differential ADC with EMIF, two low-current analog comparators, and integrated USB with on-chip transceiver. The wide operating voltage range of 2.4 V to 3.6 V suits battery-powered and USB bus-powered designs, while internal oscillators reduce external component count.
Architecturally, the device combines an 8-bit ALU with a 2-stage pipeline, 256 bytes of internal data RAM, and 4 kB of XRAM accessible via MOVX. The USB block includes a Serial Interface Engine (SIE), dedicated 1.024 kB USB FIFO buffer, and integrated 3.3 V regulator for USB signaling, enabling bus-powered operation without external USB components.
Typical applications include USB human-interface devices (HID), USB-to-UART bridges, gaming peripherals, USB sensors, low-cost instrumentation, and embedded consumer products that require a small footprint with on-board USB. The 48-TQFP package exposes enough I/O for matrix keypads, displays, and multiple serial peripherals.
When designing with this part, ensure the USB D+/D- traces are 90 ohm differential and routed as short as possible. Decouple VDD with 100 nF plus 4.7 uF bulk capacitors placed close to the pins, and follow Silicon Labs reference design guidelines for EMI/ESD on the USB connector.
This page synthesizes distributor pricing, drop-in alternatives from the EFM8UB2 family, and practical design notes not consolidated in any single manufacturer document.
Drop-in alternatives for EFM8UB20F64G-A-QFP48 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with EFM8UB20F64G-A-QFP48 (same form factor and footprint) — differing in ADC, Digital I/O Pins, Package, Supply Voltage.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
EFM8UB20F64G-A-QFP48R
✅ Drop-In📋 Reference alternative (not in catalog)
EFM8UB20F64G-B-QFP48
✅ Drop-In📋 Reference alternative (not in catalog)
EFM8UB20F64G-B-QFP48R
✅ Drop-In📋 Reference alternative (not in catalog)
EFM8UB20F64G-QFP48
✅ Drop-In📋 Reference alternative (not in catalog)
EFM8UB20F64G-A-QFP32
✅ Drop-In📋 Reference alternative (not in catalog)
EFM8UB20F64G-A-QFP48 Maximum Ratings & Electrical Characteristics
| Core | CIP-51 (8051-compatible, 8-bit, pipelined) |
| Maximum CPU Clock | 48 MHz |
| Flash Memory | 64 kB |
| RAM | 4.25 kB (256 B internal + 4 kB XRAM) |
| Digital I/O Pins | 40 |
| 16-bit Timers | 6 |
| PCA Channels | 5 |
| ADC | 10-bit differential with EMIF |
| Analog Comparators | 2 with adjustable reference |
| USB | USB 2.0 Full-Speed with on-chip transceiver and clock recovery |
| Supply Voltage | 2.4 V to 3.6 V |
| Package | 48-pin TQFP (7x7 mm) |
| Operating Temperature | -40 C to +85 C |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
EFM8UB20F64G-A-QFP48 Pin Configuration
| Pin 1 | P0.0 — Port 0.0 / I/O |
| Pin 2 | P0.1 — Port 0.1 / I/O |
| Pin 3 | P0.2 — Port 0.2 / I/O |
| Pin 4 | P0.3 — Port 0.3 / I/O |
| Pin 5 | P0.4 — Port 0.4 / I/O |
| Pin 6 | P0.5 — Port 0.5 / I/O |
| Pin 7 | P0.6 — Port 0.6 / I/O |
| Pin 8 | P0.7 — Port 0.7 / I/O |
| Pin 9 | VDD — Supply voltage (2.4 V to 3.6 V) |
| Pin 10 | VSS — Ground |
| Pin 11 | P1.0 — Port 1.0 / I/O |
| Pin 12 | P1.1 — Port 1.1 / I/O |
| Pin 13 | P1.2 — Port 1.2 / I/O |
| Pin 14 | P1.3 — Port 1.3 / I/O |
| Pin 15 | P1.4 — Port 1.4 / I/O |
| Pin 16 | P1.5 — Port 1.5 / I/O |
| Pin 17 | P1.6 — Port 1.6 / I/O |
| Pin 18 | P1.7 — Port 1.7 / I/O |
| Pin 19 | P2.0 — Port 2.0 / I/O |
| Pin 20 | P2.1 — Port 2.1 / I/O |
| Pin 21 | P2.2 — Port 2.2 / I/O |
| Pin 22 | P2.3 — Port 2.3 / I/O |
| Pin 23 | P2.4 — Port 2.4 / I/O |
| Pin 24 | P2.5 — Port 2.5 / I/O |
| Pin 25 | P2.6 — Port 2.6 / I/O |
| Pin 26 | P2.7 — Port 2.7 / I-O |
| Pin 27 | P3.0 — Port 3.0 / I/O |
| Pin 28 | P3.1 — Port 3.1 / I/O |
| Pin 29 | P3.2 — Port 3.2 / I/O |
| Pin 30 | P3.3 — Port 3.3 / I/O |
| Pin 31 | P3.4 — Port 3.4 / I/O |
| Pin 32 | P3.5 — Port 3.5 / I/O |
| Pin 33 | P3.6 — Port 3.6 / I/O |
| Pin 34 | P3.7 — Port 3.7 / I/O |
| Pin 35 | D+ — USB D+ data line (differential) |
| Pin 36 | D- — USB D- data line (differential) |
| Pin 37 | VBUS — USB VBUS sense input (5 V tolerant) |
| Pin 38 | VREG — Internal 3.3 V regulator output (decouple with 1 uF) |
| Pin 39 | /RST — Active-low reset (C2 debug) |
| Pin 40 | P4.0 — Port 4.0 / I/O |
| Pin 41 | P4.1 — Port 4.1 / I/O |
| Pin 42 | P4.2 — Port 4.2 / I/O |
| Pin 43 | P4.3 — Port 4.3 / I/O |
| Pin 44 | P4.4 — Port 4.4 / I/O |
| Pin 45 | P4.5 — Port 4.5 / I/O |
| Pin 46 | P4.6 — Port 4.6 / I/O |
| Pin 47 | P4.7 — Port 4.7 / I/O |
| Pin 48 | GND — Ground |
Typical Applications
EFM8UB20F64G-A-QFP48 is suitable for 6 applications: USB HID Keyboard / Mouse, USB-to-UART Bridge, Gaming Peripherals (Joystick / Gamepad), Industrial USB Sensor Modules, USB Dongle for Consumer Electronics, Low-Cost Test & Measurement Probe.
USB HID Keyboard / Mouse
The EFM8UB20F64G-A-QFP48 fits USB HID input devices because it integrates a USB 2.0 full-speed transceiver and SIE that meet HID polling requirements at 1 ms intervals without external PHY. The 48 MHz CIP-51 core delivers about 25 MIPS, enough to scan a matrix keypad, debounce keys, and emit HID reports concurrently. Its 64 kB Flash holds USB stacks, HID report descriptors, and application firmware; 4 kB XRAM buffers HID reports and ring-chains. The 40 GPIO pins easily drive a 8x16 key matrix plus indicator LEDs.
Recommended
USB-to-UART Bridge
The on-chip USB full-speed SIE and 6 x 16-bit timers make the EFM8UB20F64G-A-QFP48 ideal for USB-to-UART bridges that replace legacy RS-232 ports. The 48 MHz CPU and 4 kB XRAM sustain 921600 bps UART throughput while running USB CDC ACM concurrently, and the internal 3.3 V regulator powers the USB pull-up without external LDO. The 48-TQFP exposes enough pins to add hardware flow control (RTS/CTS), GPIO handshake lines, and status LEDs, all from a single 5 V bus-powered supply.
Recommended
Gaming Peripherals (Joystick / Gamepad)
The 10-bit differential ADC with EMIF and 5 PCA channels let the EFM8UB20F64G-A-QFP48 sample analog sticks and triggers at low latency while running USB HID gamepad reports. The integrated USB PHY removes external components, shrinking PCB area for compact controller designs. With 40 GPIO, designers can matrix-scan 16+ buttons, drive RGB LEDs via PWM, and read Hall-effect triggers through the ADC - all within the 64 kB Flash budget. The 2.4-3.6 V supply range supports single-cell Li-ion operation.
Recommended
Industrial USB Sensor Modules
The 10-bit differential ADC with EMIF, two analog comparators, and 48 MHz CIP-51 core make the EFM8UB20F64G-A-QFP48 well-suited to industrial USB sensor modules such as temperature loggers, current probes, and pressure transducers. The ADC samples up to 32 channels externally, while the comparators enable fast over-threshold alarms without CPU overhead. The integrated USB bus-powered supply simplifies field-deployed sensor pods; 64 kB Flash accommodates USBTMC or vendor-class protocols and calibration tables.
Recommended
USB Dongle for Consumer Electronics
USB dongles for wireless receivers, license keys, or firmware programmers benefit from the EFM8UB20F64G-A-QFP48's small 48-TQFP footprint and integrated USB PHY. The 2.4-3.6 V supply directly powers the MCU from USB VBUS through an internal regulator, so the entire dongle fits on a 15x20 mm PCB. With 64 kB Flash and 4 kB XRAM the device can store pairing keys, vendor descriptors, and application firmware while the CIP-51 core handles HID or vendor-class enumeration in under 100 ms.
Recommended
Low-Cost Test & Measurement Probe
The 10-bit differential ADC with EMIF, 6 x 16-bit timers, and 5 PCA channels let the EFM8UB20F64G-A-QFP48 act as a USB-connected oscilloscope probe, logic analyzer front-end, or signal injector. USB bus-powered operation eliminates batteries, while the 48 MHz CPU runs signal processing and USB transfers simultaneously. With 40 GPIO the device can expose a logic-analyzer header, and 64 kB Flash holds USBTMC firmware, calibration constants, and a small UI for vendor commands.
Recommended
Recommended Products Summary
Engineering reference data for EFM8UB20F64G-A-QFP48 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | EFM8UB20F64G-A-QFP48R | EFM8UB20F64G-B-QFP48 | EFM8UB20F64G-B-QFP48R | EFM8UB20F64G-QFP48 | EFM8UB20F64G-A-QFP32 |
|---|---|---|---|---|---|---|
| Package | TQFP-48 (7x7 mm) | TQFP-48 (7x7 mm) - same | TQFP-48 (7x7 mm) - same | TQFP-48 (7x7 mm) - same | TQFP-48 (7x7 mm) - same | TQFP-32 - smaller pinout |
| Brand | Silicon Labs | Silicon Labs | Silicon Labs | Silicon Labs | Silicon Labs | Silicon Labs |
| CPU Core | CIP-51 (8051) 8-bit @ 48 MHz | CIP-51 (8051) 8-bit @ 48 MHz | CIP-51 (8051) 8-bit @ 48 MHz | CIP-51 (8051) 8-bit @ 48 MHz | CIP-51 (8051) 8-bit @ 48 MHz | CIP-51 (8051) 8-bit @ 48 MHz |
| Flash Memory | 64 kB | 64 kB | 64 kB | 64 kB | 64 kB | 64 kB |
| RAM | 4.25 kB | 4.25 kB | 4.25 kB | 4.25 kB | 4.25 kB | 4.25 kB |
| USB | USB 2.0 FS with on-chip PHY | USB 2.0 FS with on-chip PHY | USB 2.0 FS with on-chip PHY | USB 2.0 FS with on-chip PHY | USB 2.0 FS with on-chip PHY | USB 2.0 FS with on-chip PHY |
| Silicon Revision | A | A | B | B | Pre-A | A |
| Packaging Format | Tray | Tape-and-Reel | Tray | Tape-and-Reel | Tray | Tray |
Key Differentiators
- Tray packaging format suited for prototype runs (vs EFM8UB20F64G-A-QFP48R)
- A silicon revision - latest qualified die in many production designs (vs EFM8UB20F64G-B-QFP48)
- 48-pin TQFP for maximum GPIO exposure (vs EFM8UB20F64G-A-QFP32)
Design Notes
Route USB D+ and D- as a 90 ohm differential pair on the top layer, with continuous ground reference below. Keep the differential pair length-matched within 150 mil and as short as practical (under 50 mm). Place the ESD protection array within 3 mm of the USB connector and the VBUS decoupling capacitor within 5 mm of the VBUS pin. Avoid splitting the ground plane beneath the USB traces; this minimizes impedance discontinuities that cause USB compliance failures.
Place a 100 nF ceramic decoupling capacitor as close as possible to each VDD pin, plus a single 4.7 uF bulk capacitor on the main supply rail. The internal 3.3 V regulator on the VREG pin requires a 1 uF external decoupling capacitor within 2 mm. VBUS sensing on pin 37 should be connected through a voltage divider or directly to the USB 5 V line; do not exceed 5.5 V on VBUS or pin damage may result. Power-on reset timing depends on the rise rate of VDD - if VDD ramps slower than 1 ms, add an external RC delay on /RST.
Do not omit the 1.5 kohm pull-up resistor on D+ for full-speed USB enumeration - the internal pull-up is configurable but many designs still use an external resistor for stable hot-plug behavior. Avoid using port pins P0.0/P0.1 as GPIO when C2 debug pins are required in production, since they double as the debug interface; route them to a header for in-system programming. Finally, do not load VREG with more than 10 mA external current - it is sized only for internal USB PHY and decoupling, not as a general LDO.
Compliance Information
RoHS and lead-free per Silicon Labs EFM8UB2 datasheet declaration. Industrial-grade part (operating temperature -40 C to +85 C); not AEC-Q100 qualified - choose automotive-grade Cypress / NXP equivalents for vehicle applications.
