PIC16CR77T-I/ML - 8-bit MCU, 14KB ROM, 33 I/O, 20MHz | Microchip
MPN: PIC16CR77T-I/ML β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.85 | $7.85 |
| 10 | $7.2 | $72.00 |
| 100 | $6.55 | $655.00 |
| 500 | $5.92 | $2,960.00 |
| 1,000 | $5.3 | $5,300.00 |
PIC16CR77T-I/ML Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data RAM, I/O peripherals, and timers onto one silicon die. The PIC16C7x family belongs to Microchip's mid-range 14-bit instruction word architecture, positioning it in the wider hierarchy: microcontroller -> embedded MCU -> 8-bit MCU -> CMOS MCU -> semiconductor. These devices are widely deployed where deterministic real-time control, low power, and simple peripheral integration matter more than raw compute throughput.
Key features of this part include a 14-bit instruction word, Harvard bus architecture with separate program ROM and data memory, 33 I/O capable of digital I/O with selectable direction, 8-channel 8-bit ADC, capture/compare/PWM modules, a USART, and an internal oscillator that reduces bill-of-materials. Operating voltage spans 2.5V to 5.5V (typical) and the part is qualified for the -40C to +85C industrial temperature range per the 'I' suffix.
Architecturally, the PIC16CR77 uses Microchip's enhanced mid-range core with a 14-bit program word and 8-bit data path, plus a hardware multiply assist on selected variants. The ROM-based memory makes this device the lowest unit-cost option in the family for high-volume production runs where the firmware is stable. The exposed-pad QFN package improves thermal dissipation and reduces PCB footprint versus equivalent PDIP or TQFP variants.
Typical applications for the PIC16CR77T-I/ML include industrial control panels, HVAC controllers, appliance control boards, motor control, security and alarm systems, sensor signal conditioning, and consumer electronics where code-stable high-volume pricing matters most. The 33 I/O and 8 ADC channels support multi-input sensor monitoring with direct transistor/MOSFET drive.
When designing with this device, verify your firmware is final before committing to mask ROM - reprogramming is impossible. The exposed pad must be soldered to the PCB ground plane for rated thermal performance, and the decoupling network must follow the manufacturer reference layout.
This page synthesizes distributor pricing, ROM-vs-flash trade-offs, drop-in PIC16F77/PIC16C77 alternatives, and practical layout notes that the manufacturer datasheet alone does not present side by side.
Drop-in alternatives for PIC16CR77T-I/ML β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16F877-I/ML
β Drop-Inπ Reference alternative (not in catalog)
PIC16F877T-I/ML
β Drop-Inπ Reference alternative (not in catalog)
PIC16C77-10/ML
β Drop-Inπ Reference alternative (not in catalog)
PIC16C77T-20I/ML
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74BT-04I/ML
β Drop-Inπ Reference alternative (not in catalog)
PIC16CR77T-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C7x 8-bit enhanced mid-range |
| Instruction Word Width | 14-bit |
| Program Memory Size | 14 KB (8K x 14) ROM |
| RAM Size | 368 x 8 bytes |
| Number of I/O | 33 |
| Maximum CPU Speed | 20 MHz |
| Oscillator Type | Internal (external optional) |
| Package | 44-pin VQFN Exposed Pad (ML) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (T suffix) |
| Operating Temperature | -40C to +85C (industrial, I suffix) |
| ADC | 8 channels, 8-bit (typical for family) |
| Timers | Timer0, Timer1, Timer2 (per family datasheet) |
| Communication | USART (SCI), I2C/SPI (per family datasheet) |
| PWM | Capture/Compare/PWM module (per family datasheet) |
| RoHS Status | Compliant (per distributor listings) |
| Lead Free | Yes (per distributor listings) |
PIC16CR77T-I/ML Pin Configuration
| Pin 1 | OSC1/CLKIN β Oscillator input or external clock input |
| Pin 2 | OSC2/CLKOUT β Oscillator output or clock output |
| Pin 3 | MCLR β Master Clear (reset) input, active low |
| Pin 4 | RA0/AN0 β Port A bit 0 / analog input 0 |
| Pin 5 | RA1/AN1 β Port A bit 1 / analog input 1 |
| Pin 6 | RA2/AN2 β Port A bit 2 / analog input 2 |
| Pin 7 | RA3/AN3/VREF β Port A bit 3 / analog input 3 / VREF+ |
| Pin 8 | RA4/T0CKI β Port A bit 4 / Timer0 clock input |
| Pin 9 | RA5/AN4/SS β Port A bit 5 / analog input 4 / SPI slave select |
| Pin 10 | RE0/RD/AN5 β Port E bit 0 / read control / analog input 5 |
| Pin 11 | RE1/WR/AN6 β Port E bit 1 / write control / analog input 6 |
| Pin 12 | RE2/CS/AN7 β Port E bit 2 / chip select / analog input 7 |
| Pin 13 | VSS β Ground reference |
| Pin 14 | VDD β Positive supply voltage |
| Pin 15 | RC0/T1OSO/T1CKI β Port C bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 β Port C bit 1 / Timer1 oscillator input / CCP2 |
| Pin 17 | RC2/CCP1 β Port C bit 2 / CCP1 |
| Pin 18 | RC3/SCK/SCL β Port C bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 β Port D bit 0 / Parallel Slave Port bit 0 |
| Pin 20 | RD1/PSP1 β Port D bit 1 / Parallel Slave Port bit 1 |
| Pin 21 | RD2/PSP2 β Port D bit 2 / Parallel Slave Port bit 2 |
| Pin 22 | RD3/PSP3 β Port D bit 3 / Parallel Slave Port bit 3 |
| Pin 23 | RC4/SDI/SDA β Port C bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO β Port C bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK β Port C bit 6 / USART transmit / clock |
| Pin 26 | RC7/RX/DT β Port C bit 7 / USART receive / data |
| Pin 27 | RD4/PSP4 β Port D bit 4 / Parallel Slave Port bit 4 |
| Pin 28 | RD5/PSP5 β Port D bit 5 / Parallel Slave Port bit 5 |
| Pin 29 | RD6/PSP6 β Port D bit 6 / Parallel Slave Port bit 6 |
| Pin 30 | RD7/PSP7 β Port D bit 7 / Parallel Slave Port bit 7 |
| Pin 31 | VSS β Ground reference |
| Pin 32 | VDD β Positive supply voltage |
| Pin 33 | RB0/INT β Port B bit 0 / external interrupt |
| Pin 34 | RB1 β Port B bit 1 |
| Pin 35 | RB2 β Port B bit 2 |
| Pin 36 | RB3/PGM β Port B bit 3 / LVP programming |
| Pin 37 | RB4 β Port B bit 4 |
| Pin 38 | RB5 β Port B bit 5 |
| Pin 39 | RB6/PGC β Port B bit 6 / ICSP clock |
| Pin 40 | RB7/PGD β Port B bit 7 / ICSP data |
| Pin 41 | VSS β Ground reference |
| Pin 42 | VDD β Positive supply voltage |
| Pin 43 | NC β Not connected (per datasheet) |
| Pin 44 | NC β Not connected (per datasheet) |
Typical Applications
PIC16CR77T-I/ML is suitable for 7 applications: Industrial Control Panels, HVAC and Appliance Controllers, Security and Alarm Systems, Sensor Signal Conditioning, Motor Control and Drives, Consumer Electronics Embedded Control, Automotive Body Electronics (Non-Safety).
Industrial Control Panels
The PIC16CR77T-I/ML fits industrial control panels through its 33 digital I/O that directly drive relays, LEDs, and optocouplers, plus the 8-channel 8-bit ADC that reads 4-20 mA sensor inputs via external shunt resistors. At 20 MHz, the part services real-time keypad scanning and HMI display updates without jitter. The factory mask-ROM design makes the lowest unit cost in production runs of 10k+ panels. Industrial-grade -40C to +85C operation is rated by the I-suffix.
Recommended
HVAC and Appliance Controllers
In HVAC and appliance controllers, the PIC16CR77T-I/ML provides 8 PWM channels via its Capture/Compare/PWM modules to drive triac phase-angle controls for fan motors and compressor valves. The 14KB ROM holds full PID algorithm plus user-interface state machines. Internal oscillator eliminates external crystals, reducing BOM cost by 30-50 cents in mass-produced appliances. Industrial temperature range supports under-cooker and unfreezer compartment environments.
Recommended
Security and Alarm Systems
Security alarm panels use the PIC16CR77T-I/ML to monitor up to 33 zones of PIR sensors, door contacts, and glass-break detectors through the digital I/O and ADC channels. The USART connects to a GSM modem for alarm reporting, while the mask-ROM firmware prevents reverse-engineering of proprietary alarm algorithms. The 20 MHz core handles concurrent keypad scanning, siren-pattern generation, and event-logging without missing interrupts.
Recommended
Sensor Signal Conditioning
The PIC16CR77T-I/ML serves as a sensor signal conditioner for multi-channel temperature, pressure, and humidity arrays. Each ADC channel samples at 8-bit resolution with internal acquisition timing suitable for thermistor and RTD bridge outputs. The 14KB ROM holds linearization lookup tables and digital-filter routines. Industrial temperature rating suits outdoor and HVAC duct installations. The exposed-pad QFN package dissipates heat reliably when 33 I/O drive LEDs simultaneously.
Recommended
Motor Control and Drives
For low-voltage DC motor control, the PIC16CR77T-I/ML generates PWM signals via its CCP modules to drive H-bridge MOSFET drivers at up to 20 kHz switching frequency. Quadrature encoder inputs on Timer0/Timer1 enable closed-loop speed regulation. The mask-ROM firmware secures proprietary motor-control algorithms. The exposed-pad QFN package handles the modest thermal load of digital I/O switching, though external driver ICs handle the power stage.
Recommended
Consumer Electronics Embedded Control
Consumer devices such as washing machines, dishwashers, microwave ovens, and smart-home hubs use the PIC16CR77T-I/ML to coordinate user-interface keypads, displays, and actuators. The USART plus I2C/SPI peripherals connect to LCD modules, audio codecs, and wireless modules. Mask-ROM pricing makes the part attractive for sub-$50 retail products at 50k+ annual production. Industrial-grade operation handles the wide environmental range of consumer deployment.
Recommended
Automotive Body Electronics (Non-Safety)
Non-safety automotive body modules such as interior lighting controllers, seat-adjustment panels, and mirror-control units deploy the PIC16CR77T-I/ML for its PWM and digital I/O capabilities. The part is NOT AEC-Q100 qualified - for safety-relevant applications use the AEC-Q100 PIC16F877A-I/ML instead. Industrial temperature rating suits cabin environments. Mask-ROM cost advantage matters at 100k+ annual vehicle production volumes.
Recommended
Recommended Products Summary
Engineering reference data for PIC16CR77T-I/ML β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F877-I/ML | PIC16F877T-I/ML | PIC16C77-10/ML | PIC16C77T-20I/ML | PIC16C74BT-04I/ML |
|---|---|---|---|---|---|---|
| Package | 44-pin VQFN Exposed Pad (ML) | 44-pin VQFN Exposed Pad (ML) - same | 44-pin VQFN Exposed Pad (ML) - same | 44-pin VQFN Exposed Pad (ML) - same | 44-pin VQFN Exposed Pad (ML) - same | 44-pin VQFN Exposed Pad (ML) - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Program Memory Type | 14 KB Mask ROM | 14 KB Flash | 14 KB Flash | 14 KB OTP / EPROM | 14 KB ROM | 7 KB OTP / EPROM |
| Program Memory Size | 14 KB (8K x 14) | 14 KB | 14 KB | 14 KB | 14 KB | 7 KB (-50%) |
| Maximum CPU Speed | 20 MHz | 20 MHz | 20 MHz | 10 MHz (-50%) | 20 MHz | 4 MHz (-80%) |
| Number of I/O | 33 | 33 | 33 | 33 | 33 | 33 |
| Lifecycle Status | NRND | Active (recommended for new designs) | Active | NRND / EOL | NRND / EOL | NRND / EOL |
| Field Reprogrammable | No (mask ROM) | Yes (flash, ICSP) | Yes (flash, ICSP) | No (OTP) | No (ROM) | No (OTP) |
| Approx Unit Price (1k qty) | ~$5.30 | $6.50-$7.50 (flash premium) | $6.50-$7.50 | $5.00-$6.00 | $5.50-$6.50 | $4.00-$5.00 (smaller memory) |
Key Differentiators
- Lowest unit cost in family for high-volume production (vs PIC16F877-I/ML)
- 44-pin VQFN Exposed Pad for compact designs (vs PIC16CR77-I/P (PDIP variant))
- 33 I/O in mid-range 8-bit core (vs PIC16C74BT-04I/ML)
- Industrial temperature range qualification (vs Consumer-grade PIC variants)
Design Notes
CRITICAL: The PIC16CR77 uses factory mask-programmed ROM. You must submit the final firmware HEX file to Microchip before wafer fabrication - there is no field reprogramming path. For development and pre-production, use the flash-based PIC16F877-I/ML in the same VQFN-44 footprint, then convert to the CR77 mask-ROM only when firmware is locked. Mistakes in the ROM image cannot be patched in the field; entire wafer batches must be scrapped.
The 44-pin VQFN Exposed Pad (ML) package dissipates heat primarily through the underside pad. The exposed pad MUST be soldered to the PCB ground plane with multiple thermal vias for rated thermal performance. Use at least 9 thermal vias in a 3x3 grid pattern under the pad. Without proper thermal connection, junction temperature can exceed 125C ratings even at moderate 20 MHz operation, especially with 33 I/O switching simultaneously.
Place a 100 nF decoupling capacitor within 3 mm of each VDD pin (pins 14, 32, 42) with a wide ground trace to the nearest VSS pin. Add a 10 uF bulk capacitor at the board entry point. Route the MCLR reset line away from high-frequency switching nodes and consider a 10 kohm pull-up and 100 nF capacitor for clean reset behavior. Keep oscillator traces short and surround them with ground pour to minimize EMI.
When using the USART at high baud rates, ensure the TX/RX traces are impedance-matched and short. For SPI communications above 5 MHz, add source-series termination resistors (30-33 ohm) close to the driving pin. The I2C bus requires pull-up resistors sized to the bus capacitance - typical values are 2.2 kohm to 10 kohm at 100-400 kHz. Use the MSSP peripheral in I2C mode rather than bit-banging to avoid timing violations.
The 44-pin VQFN has fine pitch (typically 0.5 mm) - use 0.1 mm (4 mil) trace width with 0.075 mm spacing inside the package footprint. Escape routes require microvia-in-pad or dogbone fanout patterns to the inner rows. Avoid routing traces under the exposed pad except for ground stitching vias. Reference the Microchip AN1257 application note for VQFN-44 layout recommendations to achieve a first-pass successful assembly.
Compliance Information
RoHS compliant and lead-free per distributor listings. Not AEC-Q100 qualified - choose PIC16F877A-I/ML for automotive. REACH and conflict-mineral compliance status not explicitly stated in verified web data.
