PIC16C74AT-20I/PQ - 8-Bit 20MHz OTP MCU, 7KB | Microchip
MPN: PIC16C74AT-20I/PQ ✗ סוף ייצורPIC16C74AT-20I/PQ סקירה
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, working RAM, and peripheral blocks around a Harvard architecture bus. The PIC16C7X family is the mid-range tier of Microchip's classic PIC line, sitting between the baseline PIC16C5X and the high-performance PIC17C/PIC18C families. PIC MCUs are characterized by their RISC instruction set, single-cycle execution at the oscillator rate, and predictable interrupt latency, which has made them a long-standing choice for embedded control in industrial, automotive, and consumer products.
Key features include 13 interrupt sources, a 200 ns instruction cycle at 20 MHz, an 8-level deep hardware stack, and a watchdog timer with its own on-chip RC oscillator for fail-safe recovery. The device supports in-circuit serial programming (ICSP) via RB6/RB7, allowing the OTP memory to be programmed after PCB assembly. The brown-out reset and power-on reset blocks protect the controller during supply transients in harsh industrial environments.
The architecture uses a 14-bit instruction word with separate code and data buses, enabling simultaneous instruction fetch and data access for deterministic throughput. The ADC block provides 8 inputs with 8-bit resolution, and the capture/compare/PWM module supports timing-critical motor and power-conversion applications. The 33 I/O pins feature high-current sink/source capability for direct LED and relay drive.
Typical applications include industrial control panels, sensor signal conditioning, motor drive interface, embedded instrumentation, and legacy replacement designs migrating from PIC16C5X baselines. The industrial temperature range and OTP memory make it well-suited for cost-sensitive volume production where firmware is finalized at board build time.
When designing with this device, remember that OTP memory cannot be re-programmed in the field; for development and low-volume production consider the PIC16F74 flash equivalent. The 44-MQFP package requires careful thermal management at high clock rates, and decoupling capacitors must be placed within 5 mm of the VDD pins per the Microchip datasheet.
This page synthesizes distributor pricing, drop-in pin-compatible alternatives, and practical design notes not found in the standalone manufacturer datasheet.
חלופות תחליף ישיר עבור PIC16C74AT-20I/PQ — אותו מארז, תואם פין-לפין. חלקים במארז שונה הדורשים עיבוד מחדש של ה-PCB אינם נכללים.
וריאנטים בסדרה זו
דגמים מאותה סדרה התואמים Drop-in עם PIC16C74AT-20I/PQ (אותו גורם צורה וטביעת רגל) — שונים ב Package, Serial Interfaces, ADC, Operating Temperature Range, Core.
PIC16C74A-20I/PQ
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←PIC16C74AT-20/PQ
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←PIC16C74AT-10I/PQ
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←PIC16C74AT-10E/PQ
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←PIC16C74AT-20I/PT
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←PIC16C74A-20E/PQ
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←PIC16C74AT-20I/PQ דירוגים מרביים ומאפיינים חשמליים
| Core Architecture | PIC16C / Mid-Range 8-bit RISC |
| Program Memory Size | 7 KB (4K x 14) |
| Program Memory Type | OTP (One-Time Programmable) |
| RAM Size | 192 x 8 bytes |
| EEPROM Data Memory | None (OTP part - no on-chip EEPROM) |
| Maximum CPU Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns at 20 MHz |
| Number of I/O Pins | 33 |
| Number of Interrupts | 13 sources |
| Hardware Stack Depth | 8 levels |
| ADC | 8-channel, 8-bit resolution |
| Timers | Timer0, Timer1, Timer2 |
| Capture/Compare/PWM | Yes (CCP module) |
| Serial Interfaces | USART/SCI, SSP (SPI/I2C) |
| Watchdog Timer | Yes, with dedicated on-chip RC oscillator |
| Brown-out Reset | Yes |
| In-Circuit Serial Programming | Yes (ICSP via RB6/RB7) |
| Supply Voltage (VDD) | 4.0 V to 6.0 V (typical 5 V) |
| טווח טמפרטורת פעולה | -40C to +85C (Industrial grade, "I" suffix) |
| Package Type | 44-pin MQFP (Metric Quad Flat Pack), 10x10 mm |
| Package Code | /PQ |
| סוג הרכבה | Surface Mount |
| סטטוס RoHS | Unknown (legacy part - verify per lot) |
תצורת פינים של PIC16C74AT-20I/PQ
| פין 1 | MCLR/VPP — Master Clear (active-low reset) / ICSP programming voltage input |
| פין 2 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| פין 3 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| פין 4 | RA2/AN2 — PORTA bit 2 / Analog input 2 |
| פין 5 | RA3/AN3/VREF — PORTA bit 3 / Analog input 3 / ADC voltage reference |
| פין 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input (open-drain) |
| פין 7 | RA5/AN4/SS — PORTA bit 5 / Analog input 4 / SPI slave select |
| פין 8 | RE0/RD/AN5 — PORTE bit 0 / Read control for parallel slave port / Analog input 5 |
| פין 9 | RE1/WR/AN6 — PORTE bit 1 / Write control for parallel slave port / Analog input 6 |
| פין 10 | RE2/CS/AN7 — PORTE bit 2 / Chip select for parallel slave port / Analog input 7 |
| פין 11 | VDD — Positive supply voltage (5V typical) |
| פין 12 | VSS — Ground reference |
| פין 13 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| פין 14 | OSC2/CLKOUT — Oscillator crystal output / clock output (Fosc/4) |
| פין 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| פין 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 I/O |
| פין 17 | RC2/CCP1 — PORTC bit 2 / CCP1 (Capture/Compare/PWM) I/O |
| פין 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| פין 19 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| פין 20 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| פין 21 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| פין 22 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| פין 23 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| פין 24 | RC5/SDO — PORTC bit 5 / SPI data out |
| פין 25 | RC6/TX/CK — PORTC bit 6 / USART async transmit / sync clock |
| פין 26 | RC7/RX/DT — PORTC bit 7 / USART async receive / sync data |
| פין 27 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| פין 28 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| פין 29 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| פין 30 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| פין 31 | VSS — Ground reference (second VSS pin) |
| פין 32 | VDD — Positive supply voltage (second VDD pin) |
| פין 33 | RB0/INT — PORTB bit 0 / External interrupt input |
| פין 34 | RB1 — PORTB bit 1 |
| פין 35 | RB2 — PORTB bit 2 |
| פין 36 | RB3 — PORTB bit 3 |
| פין 37 | RB4 — PORTB bit 4 |
| פין 38 | RB5 — PORTB bit 5 |
| פין 39 | RB6/PGC — PORTB bit 6 / ICSP clock (programming) |
| פין 40 | RB7/PGD — PORTB bit 7 / ICSP data (programming) |
| פין 41 | NC — Not connected (per datasheet) |
| פין 42 | NC — Not connected (per datasheet) |
| פין 43 | NC — Not connected (per datasheet) |
| פין 44 | NC — Not connected (per datasheet) |
יישומים טיפוסיים
PIC16C74AT-20I/PQ מתאים עבור 6 יישוםs: Industrial Process Control Panels, HVAC Control Systems, Automotive Dashboard Controllers (Legacy), Security Alarm Panels, Consumer Appliance Control, Motor Control and Stepper Drive.
Industrial Process Control Panels
The PIC16C74AT-20I/PQ fits industrial process control panels because its 33 digital I/O pins, 8-channel 8-bit ADC, and industrial -40C to +85C temperature range handle analog sensor inputs (4-20 mA loops, RTDs, thermocouples) and digital outputs (relays, contactors, indicator lamps) directly. The 7 KB OTP memory is sufficient for typical ladder-logic-style sequence programs and PID control loops, while the 20 MHz core delivers 200 ns instruction cycles for real-time response to process variables. The device's hardware USART interfaces with panel HMI displays and PLC expansion racks, and the SSP block supports SPI to industrial ADC/DAC converters. The brown-out reset block prevents erroneous actuator commands during brown-out conditions. Designed into the panel's main control PCB in a 44-MQFP socket for serviceability, the chip gates up to 33 panel-mounted I/O via discrete drivers.
מומלץ
HVAC Control Systems
The PIC16C74AT-20I/PQ is well-suited for commercial HVAC control boards because its industrial temperature grade handles the -40C to +85C environment of rooftop units and chiller controls, and the 33 I/O interface directly with thermostats, damper motors, compressor contactors, and triac-fired heating elements. The 8-bit ADC reads multiple temperature sensors (NTC thermistors, 10K type II/III) for indoor/outdoor/coil temperature, while the CCP module generates PWM to drive variable-speed blower motors. The 7 KB OTP memory holds the scheduling, defrost-cycle logic, and EEPROM emulation routines for setpoint retention across power cycles. The 20 MHz instruction cycle is fast enough for closed-loop PI control of compressor capacity. The ICSP programming port supports in-the-field firmware updates during commissioning, reducing service inventory. The 44-MQFP package fits standard HVAC control board footprints, and the brown-out reset prevents nuisance lockouts.
מומלץ
Automotive Dashboard Controllers (Legacy)
The PIC16C74AT-20I/PQ was historically used in automotive dashboard modules for gauge clusters and body controllers, where its 33 I/O drive the segment LCDs, warning lamps, odometer stepper motors, and turn-signal inputs. The 8-channel ADC reads the fuel-level sender, oil-pressure sensor, and coolant-temperature sender with 8-bit resolution sufficient for gauge accuracy. The USART interfaces with the body control module via LIN or K-line protocol in older vehicle architectures. The 7 KB OTP program memory holds the gauge sweep, bulb-test sequence, and mileage accumulation code, with EEPROM emulation in an external 24LC02 for odometer retention. Note that the -I grade (-40C to +85C) covers passenger-compartment modules, but under-hood applications require the PIC16C74A-20E/PQ variant with the wider -40C to +125C automotive temperature range. The 20 MHz core handles CAN/LIN software stacks for legacy vehicle networks.
מומלץ
Security Alarm Panels
The PIC16C74AT-20I/PQ serves security alarm control panels where its 33 I/O scan up to 16 wired zones (PIR, door/window contacts, glass-break detectors), drive the keypad and LCD, and switch the siren and dialer outputs. The 7 KB OTP holds the arm/disarm state machine, zone-delay logic, and dialer tone-generation code. The watchdog timer with dedicated RC oscillator ensures recovery from RF-induced software faults. The 8-bit ADC monitors the backup-battery voltage and the phone-line voltage for tamper detection. The USART interfaces with the digital dialer or cellular modem module, while the SSP port drives the LCD via SPI. The -40C to +85C industrial range covers unheated garages and outdoor cabinets. The OTP memory prevents firmware tampering after deployment, an anti-reverse-engineering benefit for security equipment.
מומלץ
Consumer Appliance Control
The PIC16C74AT-20I/PQ is found in consumer appliance controllers such as washing machines, dishwashers, and microwave ovens, where its 33 I/O drive the user-interface keypad, seven-segment display, and triac-switched motor and heating loads. The 7 KB OTP memory holds the wash-cycle state machine, water-level lookup tables, and motor-control sequences. The 8-bit ADC reads water temperature and turbidity sensors via on-chip analog input channels. The CCP module generates PWM for variable-speed motor drive (universal or BLDC via external driver), and the USART interfaces with inverter boards. The OTP memory locks firmware to prevent unauthorized code modification that could void safety certifications. The 44-MQFP package is suitable for the main control PCB of mid-size appliances. The industrial temperature range covers under-cabinet and utility-room installations, though the part is commonly used within indoor-rated enclosures.
מומלץ
Motor Control and Stepper Drive
The PIC16C74AT-20I/PQ is used in stepper-motor and small-BLDC controller designs where its 33 I/O generate the phase-step waveforms for unipolar or bipolar stepper drives via external MOSFET predrivers. The 7 KB OTP memory holds the acceleration/deceleration ramp tables and microstepping algorithms. The 20 MHz instruction cycle computes new step rates every 200 ns, supporting smooth motion profiles at speeds up to several thousand steps per second. The 8-channel ADC reads the motor-current sense resistor for closed-loop current limiting, while the CCP module generates the PWM chopping signal for chopper-driver topologies. The USART provides the Modbus or RS-485 interface for industrial motion controllers. The hardware QEI (Quadrature Encoder Interface) block on PORTB supports closed-loop position feedback from incremental encoders, enabling CNC and 3D-printer motion axes.
מומלץ
סיכום מוצרים מומלצים
נתוני עזר הנדסיים עבור PIC16C74AT-20I/PQ — השוואה, הנחיות תכנון ומידע על תאימות.
מדריך בחירה
השוואה עם חלופות
| פרמטר | מוצר זה | PIC16C74A-20I/PQ | PIC16C74AT-20/PQ | PIC16C74AT-10I/PQ | PIC16C74AT-10E/PQ | PIC16C74AT-20I/PT | PIC16C74A-20E/PQ |
|---|---|---|---|---|---|---|---|
| Package | 44-MQFP (10x10) | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max CPU Frequency | 20 MHz | 20 MHz | 20 MHz | 10 MHz | 10 MHz | 20 MHz | 20 MHz |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Number of I/O | 33 | 33 | 33 | 33 | 33 | 33 | 33 |
| Temperature Grade | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Industrial (-40C to +85C) | Extended (-40C to +125C) | Industrial (-40C to +85C) | Extended (-40C to +125C) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
מבדילים עיקריים
- Industrial temperature grade (-40C to +85C) on a fully-static CMOS core (לעומתPIC16C74AT-20/PQ)
- Highest CPU frequency at 20 MHz within the PIC16C74A family (לעומתPIC16C74AT-10I/PQ)
- Standard 44-MQFP (10x10) PQ package code for socketed / wave-solder compatibility (לעומתPIC16C74AT-20I/PT)
- Drop-in compatibility with PIC16C74A-20I/PQ except for tape-and-reel packaging (לעומתPIC16C74A-20I/PQ)
הערות תכנון
Place 0.1 uF decoupling ceramic capacitors within 5 mm of each VDD pin (pins 11 and 32 on the 44-MQFP), with a 10 uF bulk tantalum or electrolytic at the board's power-entry point. The 44-MQFP package has lead pitches of 0.8 mm; use 0.5 mm-pitch or finer probing when debugging and ensure the PCB pad length is sufficient to form a reliable fillet without wicking up the lead. The MQFP thermal pad is internal and does not require external copper landing for low-power MCU operation below 100 mW.
The PIC16C74AT-20I/PQ operates from a single 4.0 V to 6.0 V supply (5 V nominal); connect both VDD pins (11 and 32) and both VSS pins (12 and 31) to ensure adequate current delivery and ground return. Brown-out reset is configurable and should be enabled in CONFIG fuses for industrial applications where supply transients are common. Add a 1 kohm pull-up on MCLR/VPP (pin 1) and a series resistor for ICSP isolation if MCLR is also used as a digital input.
OTP memory is one-time programmable - firmware bugs locked into the part cannot be corrected. Use a PIC16F74-I/PQ or PIC18F equivalent during development to allow flash-based in-circuit re-programming, then commit the final production image to PIC16C74AT-20I/PQ only after full validation. The Configuration Word (CONFIG) and ID locations must be set correctly before programming; verify oscillator selection (HS vs XT vs LP) matches the actual crystal or resonator used, otherwise the device will not start.
When driving the parallel slave port (PORTD plus PORTE control signals), keep trace lengths matched within 25 mm to avoid setup/hold violations on PSP reads from external memory or peripheral devices. The 8-bit ADC requires a clean VREF; if using internal VDD as reference, add a 10 uF plus 0.1 uF capacitor on the AVdd supply pin to reduce digital switching noise coupling into ADC samples. For USART communications above 38.4 kbaud, use shielded cable or controlled-impedance traces.
מידע על תאימות
PIC16C74AT-20I/PQ is a legacy Microchip part predating widespread RoHS documentation; verify compliance per specific lot. Not AEC-Q100 qualified for automotive - choose PIC16C74A-20E/PQ variant for -40C to +125C automotive modules. No specific halogen-free or conflict-mineral declarations found in verified web data; consult Microchip directly for current compliance documentation.
