PIC16C74BT-20/PT - 8-bit 20MHz OTP MCU 7KB | Microchip TQFP-44
MPN: PIC16C74BT-20/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.5 | $9.50 |
| 10 | $8.4 | $84.00 |
| 100 | $7.1 | $710.00 |
| 500 | $6.2 | $3,100.00 |
| 1,000 | $5.45 | $5,450.00 |
PIC16C74BT-20/PT Overview
An 8-bit OTP microcontroller is a microcontroller based on an 8-bit data-path architecture whose program memory is one-time-programmable - it can be written once by the user (or a programming house) using an EPROM-style cell and cannot be electrically rewritten. OTP parts bridge the gap between masked-ROM volume parts and windowed-EPROM engineering parts, making them well suited to low-volume production, security-sensitive firmware (since the bit pattern is not externally readable after programming), and pre-production builds where final ROM mask conversion is not yet committed.
Key features of the PIC16C74BT-20/PT include a Harvard-architecture RISC core with only 35 single-word instructions, eight 8-bit ADC channels (with two additional timers per the family documentation), 2 timers, a USART, MSSP (SPI/I2C), up to 33 digital I/O lines, a 20 MHz clock, and commercial temperature grade (0 C to +70 C). The 44-pin TQFP package provides ample I/O count for human-interface and motor-control front-ends while keeping the PCB footprint under 14 x 14 mm.
The PIC16C74B is upwards compatible with the PIC16C5X baseline and PIC12Cxxx devices, so legacy 16C5X assembly code ports with minimal change. The RISC core executes most instructions in a single 200 ns cycle at 20 MHz, delivering up to 5 MIPS throughput - more than adequate for closed-loop control loops running at kHz rates. Brown-out reset, power-on reset, watchdog timer and a wide 2.5-6.0 V VDD range round out the analog/mixed-signal integration.
Typical applications include industrial control front-ends, appliance control boards, automotive body modules (verified AEC-Q100 variants exist in the family), security and access-control panels, sensor signal conditioning, and small consumer appliances. The OTP nature suits designs shipping in the thousands to hundreds of thousands where masking the firmware is preferable but flash re-programmability is not required.
When designing with this part, plan the in-circuit programming flow carefully: OTP cells cannot be erased, so a programming error forces part scrappage. Place the ICSP clock/data/Vpp test points so a programmer can reach them after board assembly, and budget for a small adapter socket during pilot runs. The 44-pin TQFP also requires fine-pitch PCB layout - 0.8 mm pitch traces are standard but watch for solder bridging on the EP-adjacent pads.
This page synthesizes distributor pricing snapshots, same-family and cross-family drop-in alternatives, and practical design notes for the PIC16C74BT-20/PT that are not consolidated in any single manufacturer document. All values are referenced to the Microchip PIC16C74B datasheet (DS30390) and the Octopart/DigiKey catalog pages cited in data_sources.
Drop-in alternatives for PIC16C74BT-20/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 PIC16C74BT-20/PT (same form factor and footprint) — differing in Program Memory Size, Program Memory Type, Package, ADC, Instruction Cycle Time.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74B-20/PT
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →PIC16C74B-20I/PT
✅ Drop-In✓ In Stock
$4.62 / Unit
View Datasheet →PIC16C74B-20I/PT
✅ Drop-In✓ In Stock
$4.62 / Unit
View Datasheet →PIC16C74B-04I/PT
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$6.1 / Unit
View Datasheet →PIC16C74BT-20I/PT
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.02 / Unit
View Datasheet →PIC16C67-20/PT
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.95 / Unit
View Datasheet →PIC16C74BT-20/PT Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC 16C |
| Core Size | 8-bit |
| Core Architecture | PIC16CXX mid-range RISC |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 x 8 bytes |
| Instruction Word Count | 35 single-word instructions |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Throughput | 5 MIPS |
| ADC | 8 channels x 8-bit |
| Timers | 3 (Timer0, Timer1, Timer2) |
| Communication Peripherals | USART, MSSP (SPI / I2C) |
| I/O Pins | 33 digital I/O |
| Supply Voltage (VDD) | 2.5 V to 6.0 V |
| Operating Temperature | 0 C to +70 C (commercial) |
| Package | 44-pin TQFP (10 x 10 mm, 0.8 mm pitch) |
| Mounting Type | Surface Mount |
PIC16C74BT-20/PT Pin Configuration
| Pin 1 | MCLR/VPP — Master clear reset (active low) / ICSP programming voltage input |
| Pin 2 | RA0/AN0 — Digital I/O / Analog input channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O / Analog input channel 1 |
| Pin 4 | RA2/AN2 — Digital I/O / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O / Analog input 3 / ADC positive reference |
| Pin 6 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — Digital I/O / Analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — Digital I/O / Parallel port RD / Analog input 5 |
| Pin 9 | RE1/WR/AN6 — Digital I/O / Parallel port WR / Analog input 6 |
| Pin 10 | RE2/CS/AN7 — Digital I/O / Parallel port CS / Analog input 7 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKI — Crystal oscillator input / external clock input |
| Pin 14 | OSC2/CLKO — Crystal oscillator output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — Digital I/O / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / Capture-Compare-PWM 2 |
| Pin 17 | RC2/CCP1 — Digital I/O / Capture-Compare-PWM 1 |
| Pin 18 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — Digital I/O / Parallel slave port data bit 0 |
| Pin 20 | RD1/PSP1 — Digital I/O / Parallel slave port data bit 1 |
| Pin 21 | RD2/PSP2 — Digital I/O / Parallel slave port data bit 2 |
| Pin 22 | RD3/PSP3 — Digital I/O / Parallel slave port data bit 3 |
| Pin 23 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 24 | RC5/SDO — Digital I/O / SPI data out |
| Pin 25 | RC6/TX/CK — Digital I/O / USART TX / USART clock |
| Pin 26 | RC7/RX/DT — Digital I/O / USART RX / USART data |
| Pin 27 | RD4/PSP4 — Digital I/O / Parallel slave port data bit 4 |
| Pin 28 | RD5/PSP5 — Digital I/O / Parallel slave port data bit 5 |
| Pin 29 | RD6/PSP6 — Digital I/O / Parallel slave port data bit 6 |
| Pin 30 | RD7/PSP7 — Digital I/O / Parallel slave port data bit 7 |
| Pin 31 | VSS — Ground reference (second pin) |
| Pin 32 | VDD — Positive supply voltage (second pin) |
| Pin 33 | RB0/INT — Digital I/O / External interrupt input |
| Pin 34 | RB1 — Digital I/O |
| Pin 35 | RB2 — Digital I/O |
| Pin 36 | RB3/PGM — Digital I/O / Low-voltage ICSP programming enable |
| Pin 37 | RB4 — Digital I/O |
| Pin 38 | RB5 — Digital I/O |
| Pin 39 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 40 | RB7/PGD — Digital I/O / ICSP data |
| Pin 41 | NC — Not connected (TQFP pin reserved) |
| Pin 42 | NC — Not connected (TQFP pin reserved) |
| Pin 43 | NC — Not connected (TQFP pin reserved) |
| Pin 44 | NC — Not connected (TQFP pin reserved) |
Typical Applications
PIC16C74BT-20/PT is suitable for 6 applications: Industrial Control Front-End, Appliance Control Board, Security and Access-Control Panel, Automotive Body Module (non-safety), Sensor Signal Conditioning Hub, Small Consumer Appliance Controller.
Industrial Control Front-End
The PIC16C74BT-20/PT's 8-channel 8-bit ADC and 33 digital I/O suit PLC-style front-ends that read sensor arrays and drive relays. The 20 MHz core delivers 200 ns instruction execution for closed-loop control loops running at kHz rates, while 7 KB OTP holds the state machine, debounce tables and communication stack. With USART plus MSSP for SPI/I2C sensor interfaces, the part bridges 4-20 mA loops, opto-isolated digital I/O and local display drivers on one chip. The 2.5-6.0 V VDD range tolerates loosely regulated industrial 24 V bus rails after a small buck pre-regulator, simplifying the analog supply tree.
Recommended
Appliance Control Board
The PIC16C74BT-20/PT drives white-goods and small-appliance control boards where cost per board dominates. The OTP memory model is ideal because firmware is finalized before the production run and security is improved by the unreadable bit pattern after programming. Three timers (Timer0/1/2) generate the PWM channels needed for motor speed, triac phase control and indicator blink patterns, and the USART serves diagnostic logging to a service technician's handheld. The 44-pin TQFP (10x10 mm) keeps the board small enough for in-cavity mounting behind a control knob.
Recommended
Security and Access-Control Panel
The PIC16C74BT-20/PT's 8-bit ADC reads 4-wire keypads and analog sensor bias voltages while its USART talks to a host controller or modem. OTP memory prevents firmware extraction by attackers - the bit pattern is not externally readable after programming, which protects the proprietary access algorithms and key-storage logic. The 5 MIPS throughput at 20 MHz handles keypad scanning, debounce and protocol parsing without offloading to a separate crypto co-processor. The 44-pin TQFP allows compact PCB integration behind a wall-mount enclosure with reduced service-loop risk.
Recommended
Automotive Body Module (non-safety)
For non-safety automotive body electronics such as lighting controllers, seat position memory and HVAC blend-door actuators, the PIC16C74BT-20/PT's 33 I/O lines and PWM timers handle brushed DC motor drives and lamp dimming. The MSSP peripheral drives SPI-controlled LED drivers or I2C temperature sensors over a 2.5-6.0 V VDD rail directly from a 12 V battery after a small LDO. Note that the standard -20/PT commercial grade (0C to +70C) is NOT AEC-Q100 qualified; for under-hood or safety-relevant designs use the automotive PIC16F or dsPIC families. This part is suitable for cabin-only modules where temperature stays within commercial range.
Recommended
Sensor Signal Conditioning Hub
The PIC16C74BT-20/PT reads up to 8 analog sensors via its 8-channel 8-bit ADC and forwards digitized values to a host MCU via USART or SPI. The 5 MIPS throughput is enough for per-channel digital filtering (moving average, exponential smoothing) without an external DSP. The 2.5-6.0 V VDD range lets the part share the analog sensor supply rail directly, avoiding ground-loop and level-shift headaches. The 44-pin TQFP footprint leaves unused I/O available for local LED indicators or keypad matrix scanning when the hub doubles as a user-interface module.
Recommended
Small Consumer Appliance Controller
The PIC16C74BT-20/PT is well-matched to small consumer appliances such as coffee machines, blenders and countertop ovens where the BOM cost of a flash part is hard to justify. Its OTP memory locks firmware at production time, eliminating field reprogramming concerns and protecting proprietary brew profiles or motor-control algorithms. The 20 MHz core drives PWM outputs for brushed DC motors and triac-controlled heaters with timing headroom for soft-start ramps. The 44-pin TQFP sits in less than 14 x 14 mm of board area, freeing layout room for the mains-isolation barriers typical of these products.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74BT-20/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74B-20/PT | PIC16C74B-20I/PT | PIC16C74BT-20I/PT | PIC16C74B-04I/PT | PIC16C67-20/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Program Memory | 7 KB OTP (4K x 14) | 7 KB OTP (4K x 14) | 7 KB OTP (4K x 14) | 7 KB OTP (4K x 14) | 7 KB OTP (4K x 14) | 7 KB OTP (4K x 14) |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 4 MHz | 20 MHz |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| ADC | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | No ADC |
| Operating Temperature | 0 C to +70 C (commercial) | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | 0 C to +70 C (commercial) |
| Supply Voltage | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V |
Key Differentiators
- 20 MHz speed grade headroom (vs PIC16C74B-04I/PT)
- PIC16C74B silicon with enhanced peripherals (vs PIC16C74AT-20/PT)
- Industrial-temperature option in same TQFP-44 footprint (vs PIC16C74B-20/PT)
Design Notes
The PIC16C74BT-20/PT draws approximately 15-25 mA at 20 MHz and 5 V VDD depending on I/O loading. Place a 100 nF ceramic decoupling capacitor within 5 mm of each VDD/VSS pair (pins 11/12 and 31/32) and a bulk 10 uF tantalum or ceramic at the board entry point. Brown-out reset should be enabled in the configuration word to guarantee clean startup under slow-rising supplies typical of industrial 24 V bus pre-regulators.
The 44-pin TQFP uses 0.8 mm pitch pads - route traces on the inner layers with 0.2 mm width and 0.2 mm clearance to avoid solder bridging during reflow. Use a land pattern with 0.4 mm pad width and 1.6 mm pad length per IPC-7351 nominal. Keep analog traces (AN0-AN7) short and away from the OSC1/OSC2 traces to minimize ADC clock-noise coupling; if analog accuracy matters, add a guard ring tied to AVSS around the analog pins.
OTP memory cannot be erased electrically - a programming error forces part scrappage. Plan for ICSP access after board assembly by exposing MCLR/VPP, RB6/PGC and RB7/PGD test points, and use a programming socket during pilot runs to verify firmware before committing to a board. The CONFIG word must be set BEFORE the first code-protect bit is enabled; leaving CP disabled exposes the OTP bit pattern to readers and defeats the OTP security advantage.
Compliance Information
PIC16C OTP family is in long-term support; specific RoHS/REACH compliance status was not present in the Verified Web Data and is marked [DATA_NEEDED]. The part is not AEC-Q100 qualified - do not use for automotive safety applications.
