PIC16C74AT-04E/L - 8-bit 4MHz OTP MCU, 7KB, 44-PLCC | Microchip
MPN: PIC16C74AT-04E/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.85 | $9.85 |
| 10 | $8.9 | $89.00 |
| 100 | $7.95 | $795.00 |
| 500 | $7.2 | $3,600.00 |
| 1,000 | $6.55 | $6,550.00 |
PIC16C74AT-04E/L Overview
An 8-bit OTP microcontroller is a single-chip computer with non-volatile program memory (One-Time Programmable) that executes instructions on 8-bit wide data paths, designed for embedded control where firmware is finalized at production time and not field-updatable. PIC microcontrollers sit within the broader taxonomy: microcontroller -> embedded processor -> semiconductor -> integrated circuit; the PIC16C family represents Microchip's classic mid-range core using a Harvard architecture with separate program and data buses, optimized for deterministic interrupt response and low-power standby.
Key features include 7KB (4K x 14) OTP program memory, 192 bytes of data RAM, 33 digital I/O lines, an 8-channel 8-bit A/D converter, three timer modules, a synchronous serial port (SSP) supporting SPI and I2C, and a USART for asynchronous serial communication. The device draws a typical operating current in the low milliamp range at 4MHz and supports power-managed sleep modes to extend battery life in portable designs.
The PIC16C7X architecture uses a 14-bit instruction word, single-cycle execution for most instructions (excluding branches), and a hardware stack for subroutine/interrupt context saving. The integrated A/D converter is based on a successive-approximation register (SAR) topology with analog input multiplexing, enabling direct connection to sensors without an external ADC chip. Automotive-grade 'E' temperature rating extends operation from -40C to +125C.
Typical applications include industrial control systems, automotive body and powertrain sub-assemblies, appliance control boards, and instrumentation front-ends. The integrated A/D converter is particularly valuable in measurement applications such as temperature monitoring, motor speed sensing, and analog signal acquisition.
When designing with this MCU, note that OTP memory cannot be reprogrammed - select a Flash-based PIC16F or PIC18 equivalent for in-application firmware updates. The 44-PLCC package requires a socket or careful soldering; plan PCB layout with adequate clearance around the larger J-leaded footprint.
This page synthesizes distributor pricing, drop-in alternatives, and engineering design notes not found in the manufacturer datasheet alone, providing a complete reference for engineers evaluating or sourcing the PIC16C74AT-04E/L for new designs or legacy maintenance.
Drop-in alternatives for PIC16C74AT-04E/L — 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 PIC16C74AT-04E/L (same form factor and footprint) — differing in Maximum Clock Frequency, A/D Converter, Core Architecture, Instruction Set, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74A-04E/L
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.85 / Unit
View Datasheet →PIC16C74AT-04/L
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C74A-10I/L
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC16C74A-20E/PQ
✅ Drop-In✓ In Stock
$8.4 / Unit
View Datasheet →PIC16C74A-20I/L
✅ Drop-In✓ In Stock
$8.75 / Unit
View Datasheet →PIC16C745T-I/SO
✅ Drop-In✓ In Stock
$3.65 / Unit
View Datasheet →PIC16C74AT-04E/L Maximum Ratings & Electrical Characteristics
| Product Family | PIC16C7X mid-range 8-bit MCUs |
| Core Architecture | PIC RISC (Harvard) |
| Data Bus Width | 8 bit |
| Program Memory Size | 7KB (4K x 14) OTP |
| RAM Size | 192 x 8 bytes |
| Number of I/O Pins | 33 |
| Maximum Clock Frequency | 4 MHz |
| Supply Voltage | 5 V |
| Package Type | 44-pin PLCC (16.59 x 16.59 mm) |
| Mounting Type | Surface Mount |
| A/D Converter | 8-channel 8-bit SAR integrated |
| Serial Interfaces | I2C (SSP), SPI, UART/USART |
| Timer Modules | 3 (Timer0, Timer1, Timer2) |
| Temperature Grade | Automotive (E): -40C to +125C |
| Instruction Set | 14-bit mid-range PIC, 35 instructions |
| Oscillator Type | External crystal/ceramic/RC |
| Program Memory Type | One-Time Programmable (OTP) EPROM |
PIC16C74AT-04E/L Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear reset input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / analog input 3 / Vref |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / read control / analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / write control / analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / chip select / analog input 7 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground |
| Pin 13 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 14 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 osc out / Timer1 clock in |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 osc in / CCP2 |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 20 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 21 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 22 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 23 | RD0/PSP0 — PORTD bit 0 / parallel slave port bit 0 |
| Pin 24 | RD1/PSP1 — PORTD bit 1 / parallel slave port bit 1 |
| Pin 25 | RD2/PSP2 — PORTD bit 2 / parallel slave port bit 2 |
| Pin 26 | RD3/PSP3 — PORTD bit 3 / parallel slave port bit 3 |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / parallel slave port bit 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / parallel slave port bit 5 |
| Pin 29 | RD6/PSP6 — PORTD bit 6 / parallel slave port bit 6 |
| Pin 30 | RD7/PSP7 — PORTD bit 7 / parallel slave port bit 7 |
| Pin 31 | VSS — Ground |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3 — PORTB bit 3 |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 41 | NC — Not connected (per PLCC pinout) |
| Pin 42 | NC — Not connected (per PLCC pinout) |
| Pin 43 | NC — Not connected (per PLCC pinout) |
| Pin 44 | NC — Not connected (per PLCC pinout) |
Typical Applications
PIC16C74AT-04E/L is suitable for 6 applications: Automotive Body Control Modules, Industrial Process Instrumentation, Appliance Control Boards, HVAC Climate Control Systems, Point-of-Sale Terminal Embedded Controllers, Security and Alarm System Panels.
Automotive Body Control Modules
The PIC16C74AT-04E/L is well-suited for automotive body control modules such as door-lock controllers, mirror-position drivers, and interior lighting controllers. Its automotive 'E' temperature rating (-40C to +125C) handles under-dash and engine-bay thermal stress, while the integrated 8-channel 8-bit A/D converter digitizes sensor inputs like ambient light, temperature, and potentiometer wiper positions. The 33 I/O pins drive relays, MOSFET gates, and LED indicators directly, and the UART provides diagnostic communication with the body control network. With OTP memory the firmware is tamper-resistant and the part is mature enough for long-lifecycle automotive programs.
Recommended
Industrial Process Instrumentation
In industrial process instrumentation the PIC16C74AT-04E/L serves as a front-end controller for transmitter heads, panel meters, and 4-20mA loop devices. The 8-bit A/D converter reads thermocouple, RTD, or strain-gauge bridge signals (with external signal conditioning), and the integrated UART outputs digital readings to a host PLC or display. The automotive temperature grade also provides margin for factory-floor thermal extremes, and the OTP memory ensures firmware stability for the long product lifecycles typical of industrial equipment. Reliability and field-proven silicon make it a safe choice for maintenance-of-legacy systems.
Recommended
Appliance Control Boards
The PIC16C74AT-04E/L is found in major-appliance control boards for washing machines, dishwashers, and microwave ovens where the OTP memory locks the production firmware and prevents user tampering. The 33 I/O pins interface with keypads, seven-segment or LCD displays, motor-driver enable lines, and safety sensors (door switches, water-level probes). The integrated A/D converter reads thermistor inputs for temperature regulation, and the timers generate PWM signals for variable-speed motor control. The automotive temperature grade handles the thermal envelope of oven-mounted electronics, and the low power consumption supports sleep-mode energy-star ratings.
Recommended
HVAC Climate Control Systems
HVAC climate-control thermostats and zone controllers use the PIC16C74AT-04E/L to read temperature, humidity, and pressure sensors via the integrated 8-bit A/D converter and to drive triac-fired heater/cooler stages and damper motors. The wide operating temperature range handles rooftop and attic installations, while the 7KB OTP program memory supports complex control algorithms including PID loops, schedule timers, and fault-diagnostic logic. The SPI/I2C bus connects to digital sensors and EEPROM for setpoint storage, and the UART provides connectivity to building management systems.
Recommended
Point-of-Sale Terminal Embedded Controllers
Legacy point-of-sale terminals and electronic cash registers employ the PIC16C74AT-04E/L for keypad scanning, LCD character-display driving, and serial communication with the main processor. The 33 I/O lines accommodate a 4x5 matrix keypad plus individual function keys, while the integrated A/D reads battery voltage for portable-terminal power management. OTP memory prevents unauthorized firmware modification in payment-terminal applications, and the USART interfaces with magnetic-stripe readers and thermal printers. The automotive temperature grade suits outdoor kiosk deployments and food-service counter environments.
Recommended
Security and Alarm System Panels
Security alarm panels use the PIC16C74AT-04E/L to monitor zones of PIR motion sensors, door/window contacts, and glass-break detectors via the integrated A/D converter and digital I/O. OTP memory locks the firmware to prevent reverse-engineering of the security protocol, and the automotive temperature grade supports outdoor or unheated-garage installations. The 33 I/O lines accommodate 8-16 alarm zones plus keypad, siren, and dialer interfaces, and the timers drive the entry/exit delay logic. The USART connects to central-station digital communicators using Contact ID or SIA formats.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74AT-04E/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74A-04E/L | PIC16C74AT-04/L | PIC16C74A-10I/L | PIC16C74A-20E/PQ | PIC16C74A-20I/L | PIC16C745T-I/SO |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-PLCC | 44-PLCC (same) | 44-PLCC (same) | 44-PLCC (same) | 44-PLCC (same) | 44-PLCC (same) | 44-pin (SOIC variant, same I/O count) |
| Program Memory | 7KB OTP | 7KB OTP | 7KB OTP | 7KB OTP | 7KB OTP | 7KB OTP | 7KB OTP |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 10 MHz | 20 MHz | 20 MHz | 24 MHz |
| Temperature Grade | Automotive -40C to +125C | Automotive -40C to +125C | Commercial 0C to +70C | Industrial -40C to +85C | Automotive -40C to +125C | Industrial -40C to +85C | Industrial -40C to +85C |
| 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 | 33-35 (USB peripheral) |
| A/D Converter | 8-bit 8-ch SAR | 8-bit 8-ch SAR (improved) | 8-bit 8-ch SAR | 8-bit 8-ch SAR | 8-bit 8-ch SAR | 8-bit 8-ch SAR | 8-bit 8-ch SAR |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Automotive-grade temperature rating (vs PIC16C74AT-04/L)
- Integrated 8-channel 8-bit A/D converter (vs PIC16C745T-I/SO)
- OTP memory for tamper-resistant firmware (vs Flash-based PIC16F74A)
Design Notes
OTP memory cannot be reprogrammed - once the PIC16C74AT-04E/L is programmed, the firmware is permanently fixed. Verify your HEX file with the Microchip MPLAB simulator before committing to programming. If in-application updates or bug fixes are required, choose the Flash-based PIC16F74A or PIC18F equivalent instead. OTP blanks purchased from distributors must be programmed with a Microchip-approved device programmer supporting the PIC16C7X family.
Place 100nF ceramic decoupling capacitors as close as possible to each VDD pin (pins 11 and 32) and a 10uF electrolytic or ceramic at the board power entry point. The PIC16C74AT-04E/L has two VDD/VSS pairs (11/12 and 31/32) which must both be connected for proper operation. Add a bulk capacitor near the MCLR pin to filter any noise on the reset line that could cause spurious resets in electrically noisy environments like automotive systems.
The 44-pin PLCC package has J-leaded terminations on all four sides; use a socket (e.g., 44-pin PLCC through-hole or surface-mount socket) for development boards to allow easy removal and reprogramming. For production, reflow profile should not exceed the EPROM rating - peak temperature 220C for 60 seconds maximum. Keep analog traces (RA0-RA5, RE0-RE2) short and away from digital switching signals to minimize ADC noise coupling; use a ground guard ring around analog input pins if PCB area permits.
Estimated: at maximum 4MHz clock and all peripherals active, the PIC16C74AT-04E/L draws approximately 15-20mA from a 5V supply, dissipating 75-100mW of power. The automotive -40C to +125C junction temperature range applies to silicon operating limits; PCB thermal management is rarely needed at this power level. However, when operating at the upper temperature limit in an enclosed automotive underhood environment, ensure ambient temperature plus self-heating does not push junction above 125C - this is normally not an issue at sub-100mW dissipation.
Compliance Information
Compliance data not present in the verified web data. The 'E' suffix in the part number indicates an extended automotive temperature grade (-40C to +125C), but this is a Microchip-internal designation, not equivalent to formal AEC-Q100 qualification. Engineers requiring automotive certification should verify with Microchip documentation or choose PIC16F family parts explicitly listed as AEC-Q100 qualified.
