PIC16C74B-04/PT - 8-Bit CMOS MCU, 4MHz, 7KB EPROM, TQFP-44 | Microchip
MPN: PIC16C74B-04/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.04 | $4.04 |
| 10 | $3.8 | $38.00 |
| 100 | $3.4 | $340.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.55 | $2,550.00 |
PIC16C74B-04/PT Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, non-volatile program memory, working RAM, and a configurable set of peripheral interfaces. The PIC16C family uses a Harvard RISC architecture with a small instruction set (35 single-word instructions) that lets most instructions execute in one instruction cycle, providing predictable real-time behaviour with simple C or assembly code. PIC16C parts sit in the hierarchy: microcontroller -> embedded MCU -> 8-bit MCU -> CMOS RISC MCU -> Microchip PIC16C family.
Key differentiating features of the PIC16C74B include its parallel EPROM program memory (windowed variants allow UV erasure for prototyping; OTP variants are one-time programmable for production), hardware USART for asynchronous serial communications, and the Capture/Compare/PWM peripheral for timing and motor-control applications. The 8-channel 10-bit equivalent (8-bit on the 74B variant) ADC removes the need for an external converter in mixed-signal designs, while the master SSP supports both SPI and I2C peripherals without additional glue logic.
The architecture separates program and data buses (Harvard), letting instruction fetch and data access occur in the same cycle. EPROM-based program memory is preferred over Flash for legacy designs that need radiation tolerance or long-term retention without frequent firmware updates. The PIC16C74B shares its peripheral set and pinout with later PIC16F and PIC18 K-series migration paths.
Typical applications include industrial control panels, motor-drive signal conditioning, instrumentation front-ends, sensor interfaces with on-chip ADC, and embedded communication front-ends that use the USART or SSP. Its wide operating temperature range and CMOS low-power design make it suitable for harsh-environment embedded systems.
When designing with the PIC16C74B-04/PT, ensure that your compiler toolchain (MPLAB XC8 or legacy HI-TECH PICC) supports the PIC16C OTP/EPROM family and that the EPROM windowed variant is ordered for prototype development, not the OTP-only /PT production variant. Decoupling VDD with 0.1 uF + 10 uF caps and routing the MCLR pull-up correctly are mandatory.
This page combines verified distributor pricing, drop-in alternative MPNs from the PIC16C/PIC16F family, and practical design notes that go beyond the bare datasheet, giving engineers a single source for selection and sourcing.
Drop-in alternatives for PIC16C74B-04/PT — 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 PIC16C74B-04/PT (same form factor and footprint) — differing in Package, Program Memory Size, Serial Interfaces, Timers, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F74-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F747-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C74B-04I/PT
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC16C74B-20/PT
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.05 / Unit
View Datasheet →PIC16C74A-04/PT
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.1 / Unit
View Datasheet →PIC16C74B-04/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C 8-bit RISC (Harvard) |
| Program Memory Type | EPROM (OTP) |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM | 192 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 1 us @ 4 MHz |
| Supply Voltage (VDD) | 4 V to 5.5 V |
| I/O Pins | 33 |
| ADC | 8 channels, 8-bit |
| Timers | 2 x 8-bit + 1 x 16-bit |
| Capture/Compare/PWM | 2 modules |
| Serial Interfaces | SSP (SPI / I2C) + USART |
| Package | TQFP-44 (PT) |
| Mounting Type | Surface Mount |
| Instruction Set | 35 single-word instructions |
PIC16C74B-04/PT 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 / ADC reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SSP 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 (4 V to 5.5 V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator crystal input / external clock in |
| Pin 14 | OSC2/CLKOUT — Oscillator crystal output / clock out |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 I/O |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 I/O |
| 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 reference |
| Pin 32 | VDD — Positive supply voltage (4 V to 5.5 V) |
| 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 | AVDD — Analog supply voltage |
| Pin 42 | AVSS — Analog ground reference |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C74B-04/PT is suitable for 6 applications: Industrial Control Panels, Motor Drive Signal Conditioning, Sensor Interface Front-Ends, Instrumentation and Data Acquisition, Embedded Communication Front-Ends, Harsh-Environment Embedded Systems.
Industrial Control Panels
The PIC16C74B-04/PT fits industrial control panels because its 33 digital I/O lines can directly drive relays, optocouplers, and discrete indicator LEDs without external glue logic, while the 8-channel 8-bit ADC reads 4-20 mA sensor signals through a resistor shunt. Its 4 MHz clock and EPROM-based code storage provide deterministic, real-time response to keypad and limit-switch inputs, and the USART links to an HMI or PLC over RS-485 with an external transceiver. Compared with switching to a modern Cortex-M0 part, the PIC16C74B-04/PT keeps BOM cost low for high-volume panel builds.
Recommended
Motor Drive Signal Conditioning
The PIC16C74B-04/PT is well suited to motor-drive signal conditioning because its two Capture/Compare/PWM modules can generate timing references for current-sense sampling while the 8-channel ADC reads back-phase currents through external amplifiers. The 192-byte RAM and 35-instruction RISC core let a small state machine decode Hall-sensor inputs and commutate brushless-DC motors up to a few kHz electrical frequency. The EPROM program memory is preferred over Flash for drives in electrically noisy environments, where EPROM retention tolerates repeated voltage transients better than floating-gate cells.
Recommended
Sensor Interface Front-Ends
In sensor interface front-ends, the PIC16C74B-04/PT provides on-chip 8-channel 8-bit ADC, USART, and SSP peripherals that remove the need for an external ADC, level translator, or bus expander. Its 4 V to 5.5 V supply range matches common 5 V sensor rails, and the EPROM memory retains calibration data through power cycling without EEPROM wear. Typical circuits condition thermocouple, RTD, or bridge-pressure signals through op-amps into the ADC and stream results to a host over SPI or RS-232, where the PIC16C74B acts as the local microcontroller with deterministic timing.
Recommended
Instrumentation and Data Acquisition
The PIC16C74B-04/PT serves instrumentation and data acquisition modules by offering 8 analog input channels sampled by its on-chip ADC, plus USART and SSP for sending converted data to a host processor or display. The PIC16C RISC architecture completes an 8-bit ADC read in a few instruction cycles, supporting sustained sample rates around 20-50 kSPS depending on ADC configuration. With 7 KB of EPROM, designers can fit fixed-point calibration tables and small protocol stacks (Modbus RTU over USART) without external memory, simplifying the BOM for multi-channel acquisition cards.
Recommended
Embedded Communication Front-Ends
For embedded communication front-ends, the PIC16C74B-04/PT integrates a hardware USART plus an SSP configurable as SPI master/slave or I2C master/slave, allowing it to bridge between RS-232/RS-485 and an I2C sensor cluster or SPI peripheral. The 33 I/O lines provide enough headroom to add GPIO-controlled chip-select lines, flow-control signals, and status LEDs. The 4 MHz instruction cycle is fast enough to bit-bang simple protocols or run Modbus ASCII/RTU slave stacks, making the PIC16C74B a compact protocol converter on legacy field-bus nodes.
Recommended
Harsh-Environment Embedded Systems
The PIC16C74B-04/PT is often chosen for harsh-environment embedded systems where EPROM program memory tolerates radiation and high-temperature retention better than Flash. The industrial-temperature -40C to +85C variant (suffix 'I') supports outdoor enclosures, and the CMOS low-power design keeps quiescent current low for solar- or battery-powered remote nodes. The PIC16C family has a long heritage in aerospace, military, and oil-and-gas downhole tools, so designers can reuse field-proven firmware and reference designs rather than re-validating on a newer architecture.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74B-04/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F74-I/PT | PIC16F747-I/PT | PIC16C74B-04I/PT | PIC16C74B-20/PT |
|---|---|---|---|---|---|
| Package | TQFP-44 (PT) | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | EPROM (OTP), 7 KB | Flash, 7 KB | Flash, 7 KB | EPROM (OTP), 7 KB | EPROM (OTP), 7 KB |
| Maximum Clock Frequency | 4 MHz | 20 MHz | 20 MHz | 4 MHz | 20 MHz |
| Instruction Cycle | 1 us @ 4 MHz | 200 ns @ 20 MHz | 200 ns @ 20 MHz | 1 us @ 4 MHz | 200 ns @ 20 MHz |
| ADC Resolution / Channels | 8-bit / 8 channels | 8-bit / 8 channels | 8/10/12-bit / 14 channels | 8-bit / 8 channels | 8-bit / 8 channels |
| I/O Pins | 33 | 33 | 36 | 33 | 33 |
| Operating Temperature | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | 0C to +70C (commercial) |
Key Differentiators
- EPROM-based code storage for long-term retention (vs PIC16F74-I/PT)
- On-chip 8-channel 8-bit ADC and USART reduce BOM (vs PIC16C73B-04/SP (28-pin sibling))
- Stable mature product with long-term Microchip support (vs ATMEGA8-16PI (Atmel/Microchip 8-bit MCU))
Design Notes
Decouple VDD (pin 11, pin 32) with a 0.1 uF ceramic capacitor placed within 5 mm of each VDD pin, and add a single 10 uF tantalum or aluminum bulk capacitor on the same 5 V rail. Place AVDD (pin 41) decoupling (0.1 uF + 10 uF) close to the pin and tie AVSS (pin 42) to the same ground plane as VSS. The PIC16C74B-04/PT draws approximately 5-15 mA active and < 5 uA in sleep, so the bulk capacitor must hold VDD above 4 V during brief transients.
Route the crystal traces (OSC1/OSC2, pins 13-14) as short, symmetrical traces and keep the crystal case grounded to the same ground plane as VSS. Place MCLR (pin 1) pull-up resistor (typically 10 kOhm) close to the pin and avoid long traces that pick up noise; if using ICSP, route PGC (RB6) and PGD (RB7) so the programming header can be reached without removing the IC. For TQFP-44, the exposed thermal pad (if present) should be soldered to a copper pour to lower thermal resistance, though this part dissipates negligible power.
Do not assume the PIC16C74B-04/PT and PIC16F74-I/PT are interchangeable without recompiling the firmware; configuration bits (oscillator, watchdog, brown-out, code protection) differ in default and meaning. The -04 speed grade caps the oscillator at 4 MHz - configuring a 20 MHz crystal with a -04 part will violate the AC timing spec. Also note that EPROM /PT parts are OTP, so firmware bugs cannot be patched after programming; use a windowed CERDIP for prototyping. Estimated: clock input frequency divided by 4 gives instruction cycle frequency per PIC16C family datasheet.
PORTA pins (RA0-RA5) are analog-capable and multiplexed with the ADC; configure them as digital I/O by clearing the corresponding PCFG bits in the ADCON1 register before reading them as digital inputs, otherwise the digital input buffer is disabled. Keep analog traces short and away from the crystal and USART lines to avoid ADC accuracy degradation. For the USART, place the RS-232 or RS-485 transceiver within 50 mm of pins 21-22 (RC6/RC7) to keep the routing short and balanced.
Compliance Information
RoHS, REACH, lead-free, halogen-free, and conflict-mineral status not stated in the verified web data - set to unknown. The PIC16C74B family is industrial-grade, not AEC-Q100 automotive qualified.
