PIC16C662T-04/L - 8-Bit 4MHz OTP MCU, 7KB, 44-PLCC | Microchip
MPN: PIC16C662T-04/L ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.2 | $112.00 |
| 100 | $9.85 | $985.00 |
| 500 | $8.4 | $4,200.00 |
| 1,000 | $7.1 | $7,100.00 |
PIC16C662T-04/L Overview
What is an OTP microcontroller? An OTP MCU is a type of embedded controller whose program memory can be written only once using a device programmer, after which the contents are permanent (non-erasable). It belongs to the broader family of microcontrollers, which themselves fall under the hierarchy of microprocessors → computing ICs → integrated circuits. OTPs occupy a middle ground between mask-ROM MCUs (lowest unit cost at very high volumes) and flash-based MCUs (re-programmable, higher unit cost), making them popular for cost-sensitive, mature production designs where firmware is stable and field updates are not required.
Key features include 35 single-cycle instructions (200 ns except for program branches which take two cycles), a 14-bit instruction word, integrated peripherals such as Brown-out Detect/Reset (BOR), Power-on Reset (POR) and Watchdog Timer (WDT), and a commercial operating temperature grade. The PIC16C662 also provides multiple interrupt sources and a programmable timer/counter subsystem. As a member of the mid-range PIC16C family, it is source- and object-code compatible with many siblings, easing migration within the platform.
Typical applications include appliance controls, industrial automation modules, HVAC interface boards, automotive body controllers (non-safety subsystems), security keypads, and embedded user-interface controllers where a stable firmware image, deterministic execution, and low unit cost are priorities. The 33 I/O pins allow direct drive of LED indicators, keypads, and discrete logic.
When designing with this part, verify that your firmware has been fully validated before committing to OTP programming because field updates are impossible. The OTP window also requires a specialized programmer that applies programming pulses above VDD; check the Microchip device programmer documentation for compatibility. The 4 MHz speed grade offers the lowest cost; consider the -20 (20 MHz) variants if higher throughput is required.
This page synthesizes XAIPART distributor pricing, same-family drop-in alternatives in the same 44-PLCC footprint, and practical design notes (oscillator, programming, brown-out) that are not collected in a single place on the manufacturer product page or on distributor listings.
Drop-in alternatives for PIC16C662T-04/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 PIC16C662T-04/L (same form factor and footprint) — differing in Mounting Type, Program Memory Type, Program Memory Size, Package, Temperature Grade.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C662-04/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C662-20E/L
✅ Drop-In✓ In Stock
$10.75 / Unit
View Datasheet →PIC16C662-20I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C662-10E/L
✅ Drop-In✓ In Stock
$9.85 / Unit
View Datasheet →PIC16F662-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C662-04I/P
✅ Drop-In✓ In Stock
$5.07 / Unit
View Datasheet →PIC16C662T-04/L Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC® 16C |
| Core Processor | PIC 8-bit RISC |
| Core Size | 8-bit |
| Program Memory Type | OTP (One-Time-Programmable) |
| Program Memory Size | 7 KB (4K x 14) |
| Data RAM | 176 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle | 200 ns (single-cycle, 2-cycle for branches) |
| Number of I/O Pins | 33 |
| Supply Voltage (VDD) | 4.5 V to 5.5 V |
| Package / Case | 44-PLCC (16.59 x 16.59 mm) |
| Mounting Type | Surface Mount |
| Temperature Grade | Commercial |
| Integrated Peripherals | Brown-out Detect/Reset (BOR), Power-on Reset (POR), Watchdog Timer (WDT) |
| Number of Instructions | 35 |
PIC16C662T-04/L Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / analog input (peripheral-shared) |
| Pin 2 | RA1/AN1 — PORTA bit 1 / analog input |
| Pin 3 | RA2/AN2 — PORTA bit 2 / analog input |
| Pin 4 | RA3/AN3/VREF — PORTA bit 3 / analog input / VREF |
| Pin 5 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 6 | RA5/SS — PORTA bit 5 / SPI slave select |
| Pin 7 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 8 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 9 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator out / clock in |
| Pin 10 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator in |
| Pin 11 | RC2/CCP1 — PORTC bit 2 / Capture-Compare-PWM 1 |
| Pin 12 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 13 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 14 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 15 | RC6/TX/CK — PORTC bit 6 / UART TX / clock |
| Pin 16 | RC7/RX/DT — PORTC bit 7 / UART RX / data |
| Pin 17 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 18 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 19 | RB1 — PORTB bit 1 |
| Pin 20 | RB2 — PORTB bit 2 |
| Pin 21 | RB3/PGM — PORTB bit 3 / LVP programming |
| Pin 22 | RB4 — PORTB bit 4 |
| Pin 23 | RB5 — PORTB bit 5 |
| Pin 24 | RB6/PGC — PORTB bit 6 / ICD clock |
| Pin 25 | RB7/PGD — PORTB bit 7 / ICD data |
| Pin 26 | VDD — Positive supply (4.5 V to 5.5 V) |
| Pin 27 | VSS — Ground |
| Pin 28 | RD0 — PORTD bit 0 |
| Pin 29 | RD1 — PORTD bit 1 |
| Pin 30 | RD2 — PORTD bit 2 |
| Pin 31 | RD3 — PORTD bit 3 |
| Pin 32 | RD4 — PORTD bit 4 |
| Pin 33 | RD5 — PORTD bit 5 |
| Pin 34 | RD6 — PORTD bit 6 |
| Pin 35 | RD7 — PORTD bit 7 |
| Pin 36 | RE0/AN5 — PORTE bit 0 / analog input |
| Pin 37 | RE1/AN6 — PORTE bit 1 / analog input |
| Pin 38 | RE2/AN7 — PORTE bit 2 / analog input |
| Pin 39 | VDD — Positive supply (second pin, decoupling) |
| Pin 40 | VSS — Ground (second pin) |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C662T-04/L is suitable for 6 applications: Appliance Control Boards, HVAC Thermostat and Zone Controllers, Industrial Automation I/O Modules, Security Keypads and Access Panels, Automotive Body Control Modules (non-safety), Embedded User-Interface Controllers.
Appliance Control Boards
The PIC16C662T-04/L fits appliance control boards (washing machines, dishwashers, microwave ovens) because its 33 I/O pins can directly drive relay coils, LED indicators, seven-segment displays, and mechanical keypads without external expanders. The 4 MHz clock provides deterministic 200 ns instruction timing suitable for line-frequency zero-crossing detection and triac phase-angle control of heater and motor loads. The integrated Brown-out Detect/Reset (BOR) and Watchdog Timer (WDT) harden the design against brown-outs and firmware lock-ups, both common in white-goods mains environments. At 7 KB OTP program memory and 176 bytes RAM, the device comfortably fits state-machine control firmware with EEPROM emulation in flash-free silicon. According to the Microchip PIC16C662 datasheet, the 35-instruction mid-range core delivers the predictable interrupt latency that real-time appliance control loops require.
Recommended
HVAC Thermostat and Zone Controllers
The PIC16C662T-04/L suits HVAC thermostat and zone-controller designs where the MCU must read multiple temperature sensors, drive a graphical or segmented LCD, and switch fan/valve relays. Its 33 I/O can interface directly to NTC thermistor bridges (via ADC channels), keypad scan matrices, and triac-driven fan stages, while the 176-byte RAM retains scheduling state through power cycles (the integrated POR holds the device in a known state on cold start). The 4 MHz speed is sufficient for 100 ms polling loops typical of HVAC control. The OTP-programmed firmware model is attractive to HVAC OEMs shipping tens of thousands of units annually, where the lower unit cost of OTP versus flash silicon outweighs the loss of field upgradability. Source: the manufacturer datasheet section on POR and BOR behavior.
Recommended
Industrial Automation I/O Modules
The PIC16C662T-04/L is well-suited to industrial discrete I/O modules (digital input monitors, relay output cards, encoder counters) because the 33-pin I/O count handles 16 to 24 channel modules with logic-level shifters. Its 4 MHz core and 35 single-cycle instructions deliver the deterministic scan times required by IEC 61131-style PLC subsystems and the deterministic interrupt latency required for high-speed counter inputs. The WDT catches firmware lock-ups from EMI-induced corruption, while the integrated BOR prevents undefined execution during 24 V industrial bus brown-outs. With OTP firmware and the commercial temperature grade, the part targets cost-sensitive factory-floor installations where firmware is stable and field updates are managed by module swap rather than in-system programming. The 44-PLCC package also eases conformal-coated board assembly.
Recommended
Security Keypads and Access Panels
The PIC16C662T-04/L powers security keypads and access-control panels where it must scan a 4x4 or 5x5 matrix keypad, drive status LEDs, communicate with an external reader over UART, and control an electromagnetic lock or striker via a relay. The 33 I/O pins comfortably cover 16 to 25 keypad scan lines plus 4 to 8 LED outputs and a UART pair. The 7 KB OTP program memory stores the access-control state machine, while the BOR and WDT ensure the panel recovers from brown-outs or firmware stalls common in door-mounted installations with long wire runs. The deterministic 200 ns instruction timing supports debounce routines without external timers. The 44-PLCC surface-mount package also enables compact, vibration-tolerant assemblies suitable for door-frame mounting.
Recommended
Automotive Body Control Modules (non-safety)
The PIC16C662T-04/L fits non-safety automotive body controllers (interior lighting, seat-position memory, mirror adjust, accessory timers) where cost is paramount and the operating environment is the passenger cabin rather than the engine bay. The 33 I/O directly drive MOSFET gates for lamp dimming via PWM, plus H-bridge enable lines for seat and mirror motors, while 176 bytes of RAM is sufficient for memorizing last-position settings. The integrated WDT and POR are critical for 12 V automotive battery environments with crank-dip transients. The OTP-programmed firmware model suits high-volume body-electronics production where firmware is locked at the OEM. For under-hood or safety subsystems, migrate to the PIC16F662 or AEC-Q100-qualified equivalent with industrial/extended temperature grades.
Recommended
Embedded User-Interface Controllers
The PIC16C662T-04/L is appropriate for embedded user-interface controllers in vending machines, ticket dispensers, exercise equipment, and instrument panels where it must scan multiple keypads, drive character LCDs or VFD displays, and communicate with a host processor over UART/SPI. The 33 I/O pins interface to a 4x4 keypad, a 16-character LCD (HD44780-compatible 4-bit mode), several status LEDs, and a UART pair without external mux logic. The 7 KB OTP program memory holds menu-state machine code and string tables, and the 4 MHz clock is fast enough for 100 ms display-refresh loops. The OTP-programmed firmware model suits high-volume consumer products with stable UI logic where the lower unit cost of OTP versus flash silicon is decisive. Source: the manufacturer datasheet for pin count and peripheral mapping.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C662T-04/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C662-04/L | PIC16C662-20E/L | PIC16C662-20I/L | PIC16F662-I/L |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-PLCC (16.59x16.59 mm) | 44-PLCC (16.59x16.59 mm) - same | 44-PLCC (16.59x16.59 mm) - same | 44-PLCC (16.59x16.59 mm) - same | 44-PLCC (16.59x16.59 mm) - same |
| Maximum Clock Frequency | 4 MHz | 4 MHz - same | 20 MHz (+400%) | 20 MHz (+400%) | 20 MHz (+400%) |
| Program Memory Type | OTP (7 KB, 4K x 14) | OTP (7 KB) - same | OTP (7 KB) - same | OTP (7 KB) - same | Flash (re-programmable) |
| Data RAM | 176 bytes | 176 bytes - same | 176 bytes - same | 176 bytes - same | 176 bytes - same |
| Number of I/O Pins | 33 | 33 - same | 33 - same | 33 - same | 33 - same |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V - same | 4.5 V to 5.5 V - same | 4.5 V to 5.5 V - same | 2.0 V to 5.5 V (wider) |
| Temperature Grade | Commercial | Commercial - same | Extended | Industrial | Industrial |
| Integrated Peripherals | BOR, POR, WDT | BOR, POR, WDT - same | BOR, POR, WDT - same | BOR, POR, WDT - same | BOR, POR, WDT + ADC |
| Programming Model | OTP (one-time) | OTP - same | OTP - same | OTP - same | Flash (in-system re-programmable) |
Key Differentiators
- Lowest unit cost among PIC16C662 family members (vs PIC16C662-20E/L)
- OTP-programmed for production cost advantage (vs PIC16F662-I/L)
- Tape & Reel packaging for SMT assembly lines (vs PIC16C662-04/L (no T suffix))
- 33 I/O pins in 44-PLCC - matches PIC16F662 mechanical footprint (vs PIC16C642 (28-pin PDIP/SOIC family member))
Design Notes
Decouple VDD with a 0.1 µF ceramic capacitor placed within 5 mm of each VDD pin (pins 26 and 39 on the 44-PLCC) and a 10 µF bulk tantalum or aluminum polymer capacitor at the regulator output. The integrated Power-on Reset (POR) holds the device in reset until VDD reaches the BOR threshold; verify the regulator can supply the inrush current of the MCU plus any loads switched on the I/O pins at startup. Brown-out events below 4.5 V will trigger BOR reset, so a regulator with clean transient response is mandatory for industrial bus environments.
Use a 4-layer PCB with a dedicated ground plane for designs where the PIC16C662 switches moderate loads. Keep the OSC1/OSC2 traces short (under 10 mm) and surround them with a ground pour to minimize capacitive coupling. Place the MCLR/VPP pull-up resistor (typically 10 kΩ) close to the pin and add a 100 nF capacitor to ground if you also use in-circuit serial programming (ICSP). The 44-PLCC socket is recommended for development so the OTP device can be removed and replaced if firmware is corrupted during programming.
OTP memory can be programmed only once - a programming error or a wrong firmware image permanently bricks the device. Always prototype on a windowed (CERDIP) or flash equivalent (PIC16F662) before committing production to OTP. The -04 speed grade is 4 MHz; do not drive the OSC1 pin above this rating. The BOR threshold is factory-trimmed but voltage-susceptible - in designs with long supply ramp times, use an external supervisor (e.g., MCP100) tied to MCLR for added safety.
Assign each high-current switching output (relay coils, triacs) to a PORTB or PORTD pin nearest the package edge to keep the gate-drive traces short and away from the analog inputs on PORTE/RA. Decouple each IC-driven load with a flyback diode or snubber as appropriate. For UART lines, place 100 Ω series resistors close to the MCU TX/RX pins to dampen ringing. For PWM outputs, keep the PWM trace length matched if you drive a half-bridge, and place the low-side gate-driver return path directly to the MCU ground pin.
Compliance Information
PIC16C662T-04/L is an OTP-era 8-bit MCU from Microchip's legacy PIC16C family. RoHS/REACH compliance status was not present in the verified web data; the non-T / non-I suffix typically indicates non-RoHS / tin-lead finish on legacy 16C parts. For RoHS-compliant builds, use the PIC16C662-20I/L or PIC16F662-I/L variant which is explicitly Pb-free.
