CY8C3866AXI-040 - 8051 PSoC 3, 64KB Flash, 67MHz | Infineon
MPN: CY8C3866AXI-040 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.61 | $7.61 |
| 10 | $6.85 | $68.50 |
| 100 | $6.1 | $610.00 |
| 500 | $5.42 | $2,710.00 |
| 1,000 | $4.8 | $4,800.00 |
CY8C3866AXI-040 Overview
A PSoC (Programmable System-on-Chip) is a category of mixed-signal microcontroller in which the analog and digital peripheral functions are defined by routing through universal analog and digital blocks rather than fixed silicon. PSoC 3 devices specifically pair an 8051 core with high-performance programmable analog (operational amplifiers, ADCs, DACs, comparators, CapSense), programmable digital (UDBs, timers, PWM, UART, SPI, I2C, CAN, USB, LCD), and on-chip memory, sitting in the hierarchy: PSoC 3 -> mixed-signal MCU -> microcontroller -> embedded IC -> semiconductor. This makes them true system-level solutions because the same silicon can implement different peripheral sets in hardware through programmable routing.
Key features include an 8051 single-core CPU running up to 67MHz, 64KB program Flash with ECC, 8KB SRAM, and up to 2KB EEPROM. The device integrates a 12-bit SAR ADC with up to 1 Msps, multiple 8-bit IDACs, four op-amps, four configurable TCPWM blocks, full-speed USB, CAN 2.0b, and an LCD driver supporting up to 46 segments x 4 commons. Operating voltage is 0.5V to 5.5V with industrial-grade temperature range.
The architecture combines an 8051 core with a DMA controller (PHUB) supporting 8 parallel access paths, eliminating CPU stalls during data movement between peripherals and memory. The Universal Digital Blocks (UDBs) implement custom state machines and datapaths in Verilog-equivalent primitives, while the Universal Analog Blocks (UABs) configure op-amps, comparators and references.
Typical applications include industrial HMI panels with LCD and CapSense, USB peripherals (HID, CDC, vendor class), CAN-based automotive body controllers, programmable sensor signal conditioners, and low-power battery-powered instruments. Designers value the integrated LCD + touch + analog front end that would otherwise require 3-4 separate ICs.
A key design consideration is that PSoC 3 development requires PSoC Creator IDE with the CY8C38xx component catalog - bare-metal 8051 register code does not exercise the programmable routing. Plan toolchain availability before committing to architecture.
This page synthesizes Infineon distributor pricing, Infineon-documented drop-in alternatives in the same 100-TQFP footprint, and PSoC Creator-aware design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for CY8C3866AXI-040 — 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 CY8C3866AXI-040 (same form factor and footprint) — differing in Package, ADC, Mounting Type, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
CY8C3866AXI-039
✅ Drop-In📋 Reference alternative (not in catalog)
CY8C3866AXI-041
✅ Drop-In📋 Reference alternative (not in catalog)
CY8C3866AXI-035
✅ Drop-In✓ In Stock
$9.3 / Unit
View Datasheet →CY8C3866AXI-040ES2
✅ Drop-In📋 Reference alternative (not in catalog)
CY8C3866AXI-040 Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (PSoC 3) |
| Core Architecture | 8051 (single core) |
| Maximum Core Frequency | 67 MHz |
| Program Memory (Flash) | 64 KB (64K x 8) |
| SRAM | 8 KB |
| EEPROM | 2 KB (DATA EEPROM) |
| Operating Voltage Range | 0.5 V to 5.5 V |
| Package | 100-TQFP (14 x 14 mm) |
| Pin Count | 100 |
| Mounting Type | Surface Mount (gull wing) |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| ADC | 12-bit SAR, up to 1 Msps |
| DAC | 8-bit IDAC blocks |
| Communication Interfaces | USB FS, CAN 2.0b, UART, SPI, I2C |
| LCD Driver | Up to 46 segments x 4 commons |
| Touch Sensing | CapSense supported |
| RoHS Status | Compliant |
| Lead-Free | Yes |
CY8C3866AXI-040 Pin Configuration
| Pin 1 | P0[0] — GPIO / TIOA0 / PWM0 / SWDIO |
| Pin 2 | P0[1] — GPIO / TIOB0 / PWM1 |
| Pin 3 | P0[2] — GPIO / TIOA1 / PWM2 |
| Pin 4 | P0[3] — GPIO / TIOB1 / PWM3 |
| Pin 5 | P0[4] — GPIO / TIOA2 / CAN RX |
| Pin 6 | P0[5] — GPIO / TIOB2 / CAN TX |
| Pin 7 | P0[6] — GPIO / TIOA3 / SWCLK |
| Pin 8 | P0[7] — GPIO / TIOB3 |
| Pin 9 | XRES — Active-low external reset |
| Pin 10 | VCCD — Digital core supply (1.8 V regulated output) |
| Pin 11 | VDD — Digital I/O supply (0.5-5.5 V) |
| Pin 12 | VSS — Digital ground |
| Pin 13 | VSSD — Digital ground (core) |
| Pin 14 | VDDA — Analog supply |
| Pin 15 | VSSA — Analog ground |
| Pin 16 | VREF — Voltage reference input |
| Pin 17 | P1[0] — GPIO / Op-Amp OUT / ADC IN |
| Pin 18 | P1[1] — GPIO / Op-Amp IN+ / ADC IN |
| Pin 19 | P1[2] — GPIO / Op-Amp IN- / ADC IN |
| Pin 20 | P1[3] — GPIO / CapSense / ADC IN |
| Pin 21 | P1[4] — GPIO / CapSense / ADC IN |
| Pin 22 | P1[5] — GPIO / CapSense / ADC IN |
| Pin 23 | P1[6] — GPIO / CapSense / ADC IN |
| Pin 24 | P1[7] — GPIO / CapSense / ADC IN |
| Pin 25 | P2[0] — GPIO / IDAC OUT / LCD COM |
| Pin 26 | P2[1] — GPIO / IDAC OUT / LCD COM |
| Pin 27 | P2[2] — GPIO / IDAC OUT / LCD SEG |
| Pin 28 | P2[3] — GPIO / IDAC OUT / LCD SEG |
| Pin 29 | P2[4] — GPIO / LCD SEG |
| Pin 30 | P2[5] — GPIO / LCD SEG |
| Pin 31 | P2[6] — GPIO / LCD SEG |
| Pin 32 | P2[7] — GPIO / LCD SEG |
| Pin 33 | P3[0] — GPIO / I2C SCL / SPI CLK |
| Pin 34 | P3[1] — GPIO / I2C SDA / SPI MISO |
| Pin 35 | P3[2] — GPIO / SPI MOSI / UART TX |
| Pin 36 | P3[3] — GPIO / SPI SS / UART RX |
| Pin 37 | P3[4] — GPIO / UART RTS |
| Pin 38 | P3[5] — GPIO / UART CTS |
| Pin 39 | P3[6] — GPIO / TCPWM |
| Pin 40 | P3[7] — GPIO / TCPWM |
| Pin 41 | P4[0] — GPIO / TCPWM |
| Pin 42 | P4[1] — GPIO / TCPWM |
| Pin 43 | P4[2] — GPIO / TCPWM |
| Pin 44 | P4[3] — GPIO / TCPWM |
| Pin 45 | P5[0] — GPIO / USB D+ |
| Pin 46 | P5[1] — GPIO / USB D- |
| Pin 47 | VDD — Digital I/O supply |
| Pin 48 | VSS — Digital ground |
| Pin 49 | P5[2] — GPIO / LCD SEG |
| Pin 50 | P5[3] — GPIO / LCD SEG |
| Pin 51 | P5[4] — GPIO / LCD SEG |
| Pin 52 | P5[5] — GPIO / LCD SEG |
| Pin 53 | P5[6] — GPIO / LCD SEG |
| Pin 54 | P5[7] — GPIO / LCD SEG |
| Pin 55 | P6[0] — GPIO / LCD SEG |
| Pin 56 | P6[1] — GPIO / LCD SEG |
| Pin 57 | P6[2] — GPIO / LCD SEG |
| Pin 58 | P6[3] — GPIO / LCD SEG |
| Pin 59 | P6[4] — GPIO / LCD SEG |
| Pin 60 | P6[5] — GPIO / LCD SEG |
| Pin 61 | P6[6] — GPIO / LCD SEG |
| Pin 62 | P6[7] — GPIO / LCD SEG |
| Pin 63 | P7[0] — GPIO / LCD SEG |
| Pin 64 | P7[1] — GPIO / LCD SEG |
| Pin 65 | P7[2] — GPIO / LCD SEG |
| Pin 66 | P7[3] — GPIO / LCD SEG |
| Pin 67 | P7[4] — GPIO / LCD SEG |
| Pin 68 | P7[5] — GPIO / LCD SEG |
| Pin 69 | P7[6] — GPIO / LCD SEG |
| Pin 70 | P7[7] — GPIO / LCD SEG |
| Pin 71 | P8[0] — GPIO / LCD COM |
| Pin 72 | P8[1] — GPIO / LCD COM |
| Pin 73 | P8[2] — GPIO / LCD COM |
| Pin 74 | P8[3] — GPIO / LCD COM |
| Pin 75 | P8[4] — GPIO / SIO (special I/O) |
| Pin 76 | P8[5] — GPIO / SIO |
| Pin 77 | P8[6] — GPIO / SIO |
| Pin 78 | P8[7] — GPIO / SIO |
| Pin 79 | P9[0] — GPIO / SIO |
| Pin 80 | P9[1] — GPIO / SIO |
| Pin 81 | P9[2] — GPIO / SIO |
| Pin 82 | P9[3] — GPIO / SIO |
| Pin 83 | P10[0] — GPIO / SIO / Op-Amp OUT |
| Pin 84 | P10[1] — GPIO / SIO / Op-Amp OUT |
| Pin 85 | P10[2] — GPIO / SIO / Op-Amp OUT |
| Pin 86 | P10[3] — GPIO / SIO / Op-Amp OUT |
| Pin 87 | P11[0] — GPIO / Comparator IN+ |
| Pin 88 | P11[1] — GPIO / Comparator IN- |
| Pin 89 | P11[2] — GPIO / Comparator OUT |
| Pin 90 | P11[3] — GPIO / Reference |
| Pin 91 | VDD — Digital I/O supply |
| Pin 92 | VSS — Digital ground |
| Pin 93 | P12[0] — GPIO / Crystal XIN |
| Pin 94 | P12[1] — GPIO / Crystal XOUT |
| Pin 95 | P12[2] — GPIO |
| Pin 96 | P12[3] — GPIO |
| Pin 97 | P12[4] — GPIO |
| Pin 98 | P12[5] — GPIO |
| Pin 99 | P12[6] — GPIO |
| Pin 100 | P12[7] — GPIO |
Typical Applications
CY8C3866AXI-040 is suitable for 6 applications: Industrial HMI Panel with CapSense + LCD, USB HID / CDC Peripherals, CAN-Based Automotive Body Controller, Programmable Sensor Signal Conditioner, Battery-Powered Handheld Instrument, Home Appliance Control Board.
Industrial HMI Panel with CapSense + LCD
The CY8C3866AXI-040 is purpose-built for industrial human-machine interface panels because it integrates an LCD driver (up to 46 segments x 4 commons), CapSense touch sensing, four on-chip op-amps for sensor conditioning, and a 67 MHz 8051 core with 64 KB Flash to run the UI state machine - all in one chip. Place it on a 4-layer PCB with the on-chip op-amps driving a 4-wire resistive touchscreen bridge and the CapSense block scanning up to 32 buttons through the same GPIO pins. The CAN 2.0b controller provides a robust industrial backhaul to the PLC. Compared to a discrete MCU + LCD driver + touch controller stack, this single PSoC 3 device cuts the BOM by three ICs and 25 mm^2 of board area.
Recommended
USB HID / CDC Peripherals
The CY8C3866AXI-040's integrated USB 2.0 full-speed device controller with on-chip transceiver eliminates the need for an external PHY, making it ideal for USB HID keyboards, mice, vendor-class instruments, and CDC virtual COM port adapters. The 67 MHz 8051 with 8 KB SRAM handles HID report assembly and USB protocol stacks without CPU stalls, while the 64 KB Flash stores USB descriptors and HID report templates. Designers wire USB D+/D- to the dedicated pins on the 100-TQFP and use the PSoC Creator USBFS component to enumerate. The CapSense peripheral lets the same chip implement the user interface (buttons, sliders) alongside USB, shrinking USB input devices to a single IC.
Recommended
CAN-Based Automotive Body Controller
The CY8C3866AXI-040 integrates a CAN 2.0b controller that targets automotive body electronics - body control modules, door/window nodes, seat controllers, and HVAC panels - where low cost and moderate thermal range are acceptable. The 8051 core runs CANopen or J1939 stacks at 67 MHz with 8 KB SRAM enough for typical message buffers, and the 12-bit 1 Msps SAR ADC reads sensor inputs (temperature, position, current) directly without an external ADC. Pair the PSoC with a CAN transceiver such as the AMIS30542 or TJA1050 outside the chip. Industrial -40 C to +85 C grade covers most cabin and under-hood-peripheral body modules; for under-hood 125 C use, source the -040ES2 or migrate to a true AEC-Q100 PSoC 4/6 part.
Recommended
Programmable Sensor Signal Conditioner
The CY8C3866AXI-040's four on-chip op-amps, four 8-bit IDACs, 12-bit SAR ADC, and four DACs make it ideal for sensor signal conditioning where a discrete MCU + analog-front-end board would otherwise cost twice as much. The 8051 core reads the conditioned signal, applies linearization in firmware, and outputs via UART/SPI/I2C or USB. The UABs (Universal Analog Blocks) let designers reconfigure op-amp topologies - instrumentation, transimpedance, active filters - without changing the BOM. With 64 KB Flash and 8 KB SRAM, the chip implements factory calibration tables and PID loops for closed-loop sensor systems in industrial process control.
Recommended
Battery-Powered Handheld Instrument
The CY8C3866AXI-040's 0.5 V to 5.5 V supply range and low-power sleep modes make it suitable for handheld, battery-powered measurement instruments that draw from a single Li-ion or 2xAA cell. The on-chip op-amps condition the sensor inputs, the 12-bit ADC digitizes them, and the LCD driver displays results without a second chip. In deep-sleep the 8051 core halts but RTC and CapSense scanning continue to wake the chip on button touch - a typical use case for digital multimeters, portable environmental loggers, and medical point-of-care devices. Choose the -040ES2 variant for extended -40 C to +125 C operation if the device must endure sterilisation or outdoor arctic use.
Recommended
Home Appliance Control Board
The CY8C3866AXI-040 is well matched to white-goods control boards (washing machines, dishwashers, induction cooktops) where an integrated touch UI, motor-drive PWM, and a robust industrial temperature range are required in a single chip. The four TCPWM blocks generate complementary PWMs for driving IGBT or MOSFET power stages through gate drivers, the CapSense block replaces mechanical buttons, and the LCD driver displays cycle status. The 8-bit 8051 with 64 KB Flash runs the appliance state machine, water-level sensing routines, and safety interlocks. The 100-TQFP footprint is large enough to be hand-solderable for prototyping but also fully compatible with reflow production lines.
Recommended
Recommended Products Summary
Engineering reference data for CY8C3866AXI-040 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | CY8C3866AXI-039 | CY8C3866AXI-041 | CY8C3866AXI-035 | CY8C3866AXI-040ES2 |
|---|---|---|---|---|---|
| Package | 100-TQFP (14x14) | 100-TQFP (14x14) | 100-TQFP (14x14) | 100-TQFP (14x14) | 100-TQFP (14x14) |
| Brand | Infineon Technologies | Infineon Technologies | Infineon Technologies | Infineon Technologies | Infineon Technologies |
| Core | 8051 @ 67 MHz | 8051 @ 67 MHz | 8051 @ 67 MHz | 8051 @ 67 MHz | 8051 @ 67 MHz |
| Flash | 64 KB | 64 KB | 64 KB | 32 KB | 64 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 4 KB | 8 KB |
| CAN 2.0b | Yes | No | Yes | Yes | Yes |
| USB FS | Yes | Yes | Yes | Yes | Yes |
| LCD Driver | Up to 46 seg x 4 com | Up to 46 seg x 4 com | Up to 46 seg x 4 com | Up to 46 seg x 4 com | Up to 46 seg x 4 com |
| Operating Voltage | 0.5 V to 5.5 V | 0.5 V to 5.5 V | 0.5 V to 5.5 V | 0.5 V to 5.5 V | 0.5 V to 5.5 V |
| Temperature Grade | Industrial (-40 to +85 C) | Industrial | Industrial | Industrial | Extended (-40 to +125 C) |
Key Differentiators
- Only same-package variant with full CAN 2.0b + USB + LCD in one chip (vs CY8C3866AXI-039)
- Higher Flash tier than same-package -035 sibling (vs CY8C3866AXI-035)
- Extended-temperature variant available in same package (vs CY8C3866AXI-040ES2)
Design Notes
The CY8C3866AXI-040 requires two decoupling caps per rail pair (1uF and 0.1uF) within 5 mm of each VDD/VSS pin pair, plus a 1uF bulk cap on VDDA/VSSA within 10 mm of the analog supply pin. The internal 1.8 V VCCD regulator must have a 1uF ceramic on its VCCD pin; do not load VCCD externally. Estimating from the datasheet's 35 mA typical core current at 67 MHz, the regulator dissipation at 5 V input is approximately 115 mW - keep the trace short and the cap X7R 10 V rated.
The 100-TQFP has 0.5 mm pitch leads; use 0.25 mm-wide traces with 0.4 mm pads and a 4-layer stack-up (signal/GND/power/signal) to route out from all four sides. Place the 24 MHz crystal within 5 mm of P12[0] (XIN) and P12[1] (XOUT), guarded by a GND ring and isolated from switching signals. The USB D+/D- pair (P5[0]/P5[1]) must be 90 ohm differential with no stubs and length-matched within 150 mil. Estimate: 50 mm max length for USB FS without a hub to stay within the spec's rise-time budget.
When using the on-chip 12-bit SAR ADC at the 1 Msps maximum rate, place an anti-alias RC filter (typically 100 ohm + 1 nF, fc ~1.6 MHz) within 3 mm of each analog input pin and route analog grounds in a separate net tied to VSSA at one point. The op-amp outputs (P10[0]-P10[3]) should not drive capacitive loads above 50 pF without a series resistor - estimate op-amp stability may be marginal at higher C loads. Keep analog and digital sections on separate PCB regions, joined only at the AGND/DGND tie point under the chip.
Three common PSoC 3 pitfalls: (1) Using port pins for SWD (P0[6] SWCLK and P0[0] SWDIO) without disabling SWD in firmware will lock out subsequent programming - design a hardware recovery path (XRES pulled low during reset unlocks SWD). (2) The LCD segment pins share GPIO; enabling the LCD driver reassigns those pins - confirm your keyscan matrix does not collide with COM lines. (3) The CAN RX/TX pins (P0[4]/P0[5]) require external transceiver; do not connect them directly to the bus or the PSoC will be damaged by bus transients.
Compliance Information
RoHS compliant and lead-free per Infineon product page; not AEC-Q100 qualified - the -040ES2 is an engineering sample with extended thermal range but not full automotive qualification. Choose PSoC 4 or PSoC 6 AEC-Q100 parts for true automotive.
