PIC16C622T-04/SS - 8-bit OTP MCU, 3.5KB, 4MHz, SSOP-20 | Microchip
MPN: PIC16C622T-04/SS β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.55 | $25.50 |
| 100 | $2.1 | $210.00 |
| 500 | $1.78 | $890.00 |
| 1,000 | $1.49 | $1,490.00 |
PIC16C622T-04/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory, and peripherals; the PIC16C mid-range architecture uses a 14-bit instruction word with a Harvard bus and a RISC-style instruction set, delivering deterministic interrupt latency and single-cycle execution for most opcodes. The PIC16C622 specifically sits within Microchip's PIC16C62x family of OTP-only devices intended for volume production where firmware is finalized and in-system reprogrammability is not required.
Key features include 3.5KB OTP program memory (2K x 14-bit words), 128 bytes of SRAM, 13 GPIO pins, an integrated watchdog timer, a power-on reset (POR) circuit, an 8-bit timer/counter with prescaler, and brown-out detection circuitry. The 20-pin SSOP (7.50mm body width) provides a small board footprint while still supporting through-hole-compatible soldering profiles on mixed-technology assemblies.
The PIC16C622 architecture uses a 14-bit instruction word and 8-bit data path, with a two-stage instruction pipeline that allows most instructions to execute in one clock cycle. Its CMOS implementation yields low static current draw suitable for line-powered consumer and industrial equipment, and the part is well-supported by legacy MPLAB IDE development tools still maintained by Microchip for OTP PIC16C production lines.
Typical applications include consumer appliance control, industrial automation sensor interfaces, low-cost HVAC thermostats, simple closed-loop fan or pump controllers, and white-goods user-interface panels. The 4 MHz instruction rate and 13 I/O are adequate for keypad scanning, LED multiplexing, and basic serial protocols implemented in firmware.
When designing with this device, note that the OTP memory requires masked firmware at programming time and cannot be field-updated; for design revisions or firmware iteration, use the flash-based PIC16F62x family in the same SSOP-20 footprint as a drop-in alternative. A 100 nF decoupling capacitor placed within 5 mm of the VDD pin is mandatory for stable operation.
Drop-in alternatives for PIC16C622T-04/SS β 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 PIC16C622T-04/SS (same form factor and footprint) β differing in Core Architecture, Operating Temperature Range, Program Memory Size, RoHS Status.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C622-04/SS
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.18 / Unit
View Datasheet βPIC16C621-04/SS
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16F628A-I/SS
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16F627A-I/SS
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16F648A-I/SS
β Drop-Inπ Reference alternative (not in catalog)
PIC16C622T-04/SS Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit RISC Microcontroller (MCU) |
| Core Architecture | PIC16C mid-range (14-bit instruction word) |
| Program Memory Type | OTP (One-Time-Programmable) EPROM |
| Program Memory Size | 3.5 KB (2K x 14 words) |
| Data RAM Size | 128 x 8 bytes (128 bytes) |
| Maximum Clock Frequency | 4 MHz |
| Supply Voltage Range (VDD) | 3.0 V to 6.0 V |
| Number of I/O Pins | 13 |
| Package / Case | 20-SSOP (7.50 mm body width) |
| Mounting Type | Surface Mount |
| Terminal Form | Gull Wing |
| Operating Temperature Range | 0 C to +70 C (Commercial grade) |
| Oscillator Type | External oscillator support |
| Packaging | Tape and Reel (suffix "T") |
| Process Technology | CMOS |
| RoHS Status | Non-RoHS (OTP EPROM legacy product) |
PIC16C622T-04/SS Pin Configuration
| Pin 1 | RA2/AN2 β Port A bit 2 / Analog input |
| Pin 2 | RA3/AN3 β Port A bit 3 / Analog input |
| Pin 3 | RA4/T0CKI β Port A bit 4 / Timer 0 clock input |
| Pin 4 | MCLR/VPP β Master clear reset / Programming voltage input |
| Pin 5 | VSS β Ground reference |
| Pin 6 | RB0/INT β Port B bit 0 / External interrupt |
| Pin 7 | RB1 β Port B bit 1 |
| Pin 8 | RB2 β Port B bit 2 |
| Pin 9 | RB3 β Port B bit 3 |
| Pin 10 | RB4 β Port B bit 4 |
| Pin 11 | RB5 β Port B bit 5 |
| Pin 12 | RB6 β Port B bit 6 |
| Pin 13 | RB7 β Port B bit 7 |
| Pin 14 | VSS β Ground reference (digital) |
| Pin 15 | VDD β Positive supply voltage 3.0-6.0V |
| Pin 16 | OSC2/CLKOUT β Oscillator output / Clock output |
| Pin 17 | OSC1/CLKIN β Oscillator input / External clock input |
| Pin 18 | RA0/AN0 β Port A bit 0 / Analog input |
| Pin 19 | RA1/AN1 β Port A bit 1 / Analog input |
| Pin 20 | VDD β Positive supply voltage 3.0-6.0V |
Typical Applications
PIC16C622T-04/SS is suitable for 6 applications: Consumer Appliance Control, HVAC Thermostat Controller, Industrial Sensor Interface, White-Goods User Interface Panel, Simple Closed-Loop Fan/Pump Controller, Remote Control / IR Transmitter.
Consumer Appliance Control
The PIC16C622T-04/SS fits consumer appliance control boards where firmware is finalized and OTP pricing matters more than in-system reprogramming. Its 4 MHz instruction rate and 13 I/O support keypad scanning for cooktops, dishwasher cycle selectors, and microwave user interfaces, while 128 bytes of RAM handle status flags and timing counters. Compared to flash alternatives, the OTP memory reduces per-unit cost in high-volume SKUs, making it ideal for white-goods designs shipping 100k+ units annually. Brown-out detection and the integrated watchdog timer provide resilience against supply transients on switched-mode power rails commonly found in appliance environments.
Recommended
HVAC Thermostat Controller
The PIC16C622T-04/SS suits low-cost HVAC thermostat designs where the 3.0-6.0V supply matches common 5V thermostats and 4 MHz clock is sufficient for NTC thermistor sampling, setpoint comparison, and relay control. The 13 GPIO comfortably handle the LCD segments (multiplexed), up/down buttons, fan-mode switch, and heat/cool relay drivers in a single MCU. Its 0C to +70C commercial temperature range covers indoor wall-mount installations; designers should select the PIC16C622-04I/SS industrial variant for outdoor or attic-mounted units. Brown-out reset prevents the MCU from latching relays during brown-out, a critical safety feature in HVAC.
Recommended
Industrial Sensor Interface
For industrial sensor-interface modules with fixed firmware - such as proximity-sensor digitizers, optical-encoder counters, or simple pressure-transducer signal conditioners - the PIC16C622T-04/SS provides adequate GPIO count and 4 MHz throughput for polled-sensor protocols. Designers pair the MCU with a 4-20 mA loop transmitter IC and an external EEPROM for calibration constants. The OTP memory locks firmware against field tampering, which is valuable in factory-automation sensors installed in customer plants. For applications requiring the -40C to +85C industrial range, the PIC16C622-04I/SS is the same-die industrial variant sharing this footprint.
Recommended
White-Goods User Interface Panel
The PIC16C622T-04/SS drives white-goods front-panel user interfaces including the button matrix, 7-segment or LCD indicators, and buzzer control logic in washing machines, dryers, and dishwashers. Its 13 GPIO are well-matched to a 3x4 keypad (7 lines) plus 4 LED status outputs plus 2 buzzer/relay lines, all driven by firmware-implemented debounce and multiplexing. The 128 bytes of RAM comfortably hold the cycle-state machine and timing variables for typical wash programs. OTP memory prevents end-user firmware tampering while keeping the BOM cost low for high-volume appliance production runs.
Recommended
Simple Closed-Loop Fan/Pump Controller
The PIC16C622T-04/SS controls small DC fans or pumps in closed-loop configurations using a tachometer input and PWM output to the motor driver. The 4 MHz instruction cycle supports a 10 kHz PWM frequency with 8-bit resolution, smooth enough for most low-noise fan applications. Designers read the tach via the timer/counter input-capture peripheral and adjust PWM duty through firmware based on temperature or flow feedback. Its OTP memory locks the control algorithm once characterized, eliminating field firmware drift. Brown-out detection prevents motor driver latch-up if supply droops during motor stall events.
Recommended
Remote Control / IR Transmitter
The PIC16C622T-04/SS fits low-cost IR remote-control transmitters where its 4 MHz clock and 128-byte RAM are sufficient to generate 38 kHz carrier, drive the IR LED via PWM, and scan a button matrix. The 13 GPIO accommodate 4x4 button grids and the IR LED driver output. Its 3-6V supply matches 3V coin-cell or 4.5V (3xAAA) battery packs commonly used in TV/STB remotes. OTP memory locks the protocol (RC5, NEC, SIRC) so end users cannot reflash, which protects IP. The commercial temperature range covers indoor remote-control use cases.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C622T-04/SS β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C622-04/SS | PIC16C621-04/SS | PIC16F628A-I/SS | PIC16F627A-I/SS | PIC16F648A-I/SS |
|---|---|---|---|---|---|---|
| Package | 20-SSOP (7.50mm) | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 3.5KB OTP | 3.5KB OTP | 1.75KB OTP (-50%) | 3.5KB Flash (in-system) | 1.75KB Flash (in-system) | 7KB Flash (+100%) |
| RAM Size | 128 bytes | 128 bytes | 80 bytes | 224 bytes (+75%) | 128 bytes | 256 bytes (+100%) |
| Maximum Clock | 4 MHz | 4 MHz | 4 MHz | 20 MHz (+400%) | 20 MHz (+400%) | 20 MHz (+400%) |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | Flash (ICSP) | Flash (ICSP) | Flash (ICSP) |
| Temperature Range | 0C to +70C (Commercial) | 0C to +70C | 0C to +70C | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| I/O Pins | 13 | 13 | 13 | 16 (+3) | 16 (+3) | 16 (+3) |
Key Differentiators
- Higher program memory than lower-tier PIC16C621 family (vs PIC16C621-04/SS)
- Cost-optimized OTP memory for finalized firmware (vs PIC16F628A-I/SS)
- Wider supply voltage range than typical 3.3V-only MCUs (vs PIC16F627A-I/SS)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 15) and a bulk capacitor (e.g., 10 uF tantalum) near the MCU power entry point. The PIC16C622 can generate brief VDD current spikes during internal EPROM programming cycles even in run mode; adequate decoupling prevents code-fetch glitches. For battery-powered applications, use the SLEEP instruction to drop current to typical values below 1 uA.
The OTP (One-Time-Programmable) memory cannot be erased or rewritten; once a bit is programmed, it is permanent. Engineers developing new firmware should first prototype with the flash-based PIC16F628A-I/SS (same SSOP-20 pinout) and only commit to the PIC16C622T-04/SS once firmware is locked. Programming is performed using the Microchip PICSTART Plus or compatible programmer applying 13V on VPP/MCLR.
For 4 MHz operation, keep oscillator traces (OSC1/OSC2) short and surround them with a ground guard ring to minimize EMI. If using a crystal, place the load capacitors (typically 15-22 pF) within 3-5 mm of the OSC1 and OSC2 pins. The MCLR pin requires a 10 kohm pull-up to VDD and a 100 nF capacitor to ground for proper reset pulse generation; do not leave MCLR floating.
Compliance Information
PIC16C622T-04/SS is a legacy OTP EPROM device that uses SnPb (lead-tin) terminations and is therefore non-RoHS by default. RoHS-compliant versions are available from Microchip on request. Not AEC-Q100 qualified - this part is not intended for automotive safety-critical applications.
