PIC16C620AT-20I/SO - 8-Bit OTP MCU 20MHz 896B | Microchip
MPN: PIC16C620AT-20I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.73 | $0.73 |
| 10 | $0.68 | $6.80 |
| 100 | $0.62 | $62.00 |
| 500 | $0.55 | $275.00 |
| 1,000 | $0.48 | $480.00 |
PIC16C620AT-20I/SO Overview
An OTP-based microcontroller (One-Time-Programmable) is a class of non-volatile memory MCU that can be programmed once after manufacture using a device programmer, after which the program becomes permanent. Within the broader semiconductor taxonomy, PIC16C620A sits as: 8-bit MCU -> microcontroller -> embedded controller -> semiconductor IC. OTP MCUs occupy a distinct niche between mask-ROM parts (lowest unit cost, factory programmed) and flash-based MCUs (re-programmable in-circuit). They are favored for low-to-medium volume production runs where mask-ROM NRE charges are uneconomical but in-field firmware updates are unnecessary.
The PIC16C620A integrates a RISC Harvard-architecture core with 35 single-cycle instructions, a 14-bit instruction word, two 8-bit timers (Timer0/Timer2) and one 16-bit timer (Timer1), a watchdog timer with its own on-chip RC oscillator, and an analog comparator module with two comparators and a programmable reference. Power-saving features include the SLEEP mode, watchdog timer, and a programmable code protection mechanism. The core operates across 3.0V to 5.5V VDD, with brown-out detection and power-on reset integrated on-chip. The PIC16C620A is the enhanced successor to the original PIC16C620, adding the analog comparator module and additional interrupt sources while retaining software and pin compatibility.
Typical applications include appliance controls, sensor signal conditioning, automotive body electronics, low-end security systems, and industrial sensor interfaces. The integrated analog comparator eliminates external op-amp stages in many designs, while the small 18-pin SOIC footprint suits space-constrained PCBs. Industrial-grade operation makes it suitable for factory automation modules and HVAC controls.
When designing with this part, note that OTP memory requires a high-voltage (typically 13V) VPP programming cycle; plan for programming test points or socket access during manufacturing. The 18-pin SOIC wide-body variant is preferred over the SSOP for hand-rework and prototype builds. Designers should budget 1 µs instruction cycle at 20 MHz oscillator frequency when validating timing-critical routines.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes that complement the manufacturer datasheet, helping engineers select the right PIC16C variant for cost-sensitive OTP-based designs.
Drop-in alternatives for PIC16C620AT-20I/SO — 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 PIC16C620AT-20I/SO (same form factor and footprint) — differing in Program Memory Size, Program Memory Type, Timers, Operating Temperature, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C620A-20I/SO
✅ Drop-In✓ In Stock
$1.31 / Unit
View Datasheet →PIC16C620AT-20/SS
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →PIC16C621AT-20I/SO
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →PIC16C622AT-20I/SO
✅ Drop-In✓ In Stock
$1.82 / Unit
View Datasheet →PIC16C620-20I/SO
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16F627A-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F628A-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C620AT-20I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit RISC PIC16C Harvard |
| Program Memory Type | OTP (One-Time-Programmable EPROM) |
| Program Memory Size | 896 bytes (512 x 14 words) |
| RAM Size | 96 bytes |
| EEPROM Size | None (no on-chip data EEPROM) |
| Maximum CPU Speed | 20 MHz (5 MIPS) |
| Supply Voltage (VDD) | 3.0 V to 5.5 V |
| I/O Pins | 13 |
| Timers | 1 x 8-bit, 1 x 16-bit |
| Watchdog Timer | Yes (with dedicated on-chip RC oscillator) |
| Analog Comparators | 2 with programmable voltage reference |
| A/D Converter | None |
| Instruction Set | 35 single-cycle instructions, 14-bit word |
| Operating Temperature | -40°C to +85°C (Industrial) |
| Package | 18-SOIC (0.295" / 7.50 mm body width, SO) |
| Mounting Type | Surface Mount (Gull-Wing) |
PIC16C620AT-20I/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O pin, Port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O pin, Port A bit 3 |
| Pin 3 | RA4/T0CKI — Bidirectional I/O / Timer0 clock input |
| Pin 4 | MCLR/VPP — Master Clear reset (active low) / Programming voltage input |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O / External interrupt input |
| Pin 7 | RB1 — Bidirectional I/O, Port B bit 1 |
| Pin 8 | RB2 — Bidirectional I/O, Port B bit 2 |
| Pin 9 | RB3 — Bidirectional I/O, Port B bit 3 |
| Pin 10 | RB4 — Bidirectional I/O, Port B bit 4 |
| Pin 11 | RB5 — Bidirectional I/O, Port B bit 5 |
| Pin 12 | RB6 — Bidirectional I/O, Port B bit 6 |
| Pin 13 | RB7 — Bidirectional I/O, Port B bit 7 |
| Pin 14 | VDD — Positive supply voltage (3.0 V to 5.5 V) |
| Pin 15 | OSC2/CLKOUT — Oscillator crystal output / Clock output (Fosc/4) |
| Pin 16 | OSC1/CLKIN — Oscillator crystal input / External clock input |
| Pin 17 | RA0/AN0/CMP1 — Bidirectional I/O / Analog input 0 / Comparator 1 input |
| Pin 18 | RA1/AN1/CMP2 — Bidirectional I/O / Analog input 1 / Comparator 2 input |
Typical Applications
PIC16C620AT-20I/SO is suitable for 7 applications: Appliance Control Boards, Sensor Signal Conditioning, Automotive Body Electronics, Low-End Security Systems, Industrial Sensor Interfaces, HVAC Control Modules, Consumer Remote Controls.
Appliance Control Boards
The PIC16C620AT-20I/SO is well-suited for white-goods and small-appliance control boards (washing machines, microwave ovens, coffee makers, rice cookers) where the 13 I/O pins drive relays, triacs, and seven-segment displays. The integrated analog comparators handle zero-crossing detection for triac firing, eliminating external op-amp stages and reducing BOM cost. OTP memory is acceptable here because production volumes are high and firmware is fixed at release. The 18-SOIC wide-body package survives hand-solder rework during prototyping and supports automated SMT lines in volume production.
Recommended
Sensor Signal Conditioning
The PIC16C620AT-20I/SO conditions analog sensor signals using its two on-chip analog comparators and programmable voltage reference, supporting threshold-based decisions on temperature, pressure, light, or position sensors without requiring an external op-amp stage. The 96-byte RAM buffers recent samples for de-bounce or hysteresis logic, while the 20 MHz core executes comparison-and-decision cycles in under 200 ns per iteration. Designers should route sensor inputs to RA0/RA1 (CMP1/CMP2 inputs) to maximize noise immunity and place a 0.1 µF bypass capacitor within 5 mm of VDD.
Recommended
Automotive Body Electronics
For body-electronics modules (interior lighting, mirror controls, seat controllers), the PIC16C620AT-20I/SO handles timer-based PWM dimming, button debounce, and LIN-bus emulation via software on standard I/O pins. The -40°C to +85°C industrial temperature range covers most cabin environments, though under-hood or engine-bay applications require the PIC16C620A-20E/SO extended-temperature variant. The 20 MHz MIPS performance handles concurrent LED PWM and CAN/LIN message handling at typical body-network bit rates.
Recommended
Low-End Security Systems
The PIC16C620AT-20I/SO drives PIR motion sensor interfaces, reed-switch zones, and keypad scanning for low-end alarm panels. Its SLEEP mode reduces quiescent current to a few µA when the system is armed but idle, and the watchdog timer with dedicated RC oscillator catches firmware lockups even if the main crystal stops. The 13 I/O pins support up to 6 zones plus a 4x3 keypad matrix. The integrated comparators can implement glass-break detection by comparing piezoelectric transducer signals against an adaptive threshold.
Recommended
Industrial Sensor Interfaces
In factory-automation modules, the PIC16C620AT-20I/SO implements discrete I/O controllers, counter accumulators, and threshold comparators for limit-switch and proximity-sensor interfacing. The industrial -40°C to +85°C temperature range handles cabinet environments, and the watchdog timer with hardware RC oscillator protects against EMI-induced firmware crashes on the factory floor. Programming via high-voltage VPP allows in-line test programming during PCB assembly. The compact 18-SOIC package supports high-density DIN-rail modules.
Recommended
HVAC Control Modules
The PIC16C620AT-20I/SO runs the control loops for fan-speed switching, damper actuator timing, and thermostat hysteresis in split-system HVAC controllers. The two analog comparators measure thermistor bridges without ADC overhead, the 16-bit Timer1 captures zero-cross timing for triac phase control, and the 8-bit Timer0 sets the system tick rate. OTP memory is ideal here because HVAC firmware is mature and rarely changes, while the unit cost advantage compounds across high-volume HVAC production runs.
Recommended
Consumer Remote Controls
Simple IR/RF remote controls use the PIC16C620AT-20I/SO to scan a keypad matrix, encode button presses into modulated IR pulses, and manage battery-saving SLEEP cycles between button events. The 13 I/O pins support up to 12 buttons in a 4x3 matrix plus an IR LED driver, and the 20 MHz core easily meets 38 kHz carrier generation timing. The internal RC oscillator option eliminates the external crystal, reducing BOM cost and PCB area for cost-sensitive consumer remotes.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C620AT-20I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C620A-20I/SO | PIC16C621AT-20I/SO | PIC16C622AT-20I/SO | PIC16F628A-I/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC | 18-SOIC - same | 18-SOIC - same | 18-SOIC - same | 18-SOIC - same |
| Program Memory | 896 B OTP (512 x 14) | 896 B OTP (512 x 14) | 2 KB OTP (1K x 14) | 2 KB OTP (1K x 14) | 4 KB Flash (2K x 14) |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | Flash (reprogrammable) |
| RAM | 96 B | 96 B | 128 B | 128 B | 224 B |
| ADC | None | None | None | 4-ch x 8-bit | None |
| Comparators | 2 with Vref | 2 with Vref | 2 with Vref | 2 with Vref | 2 with Vref |
| UART | No | No | No | No | Yes (USART) |
| Max CPU Speed | 20 MHz / 5 MIPS | 20 MHz / 5 MIPS | 20 MHz / 5 MIPS | 20 MHz / 5 MIPS | 20 MHz / 5 MIPS |
| Operating Voltage | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 2.0 V to 5.5 V (wider) |
| Temperature Range | -40°C to +85°C (Industrial) | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C |
| Approx. Unit Price (1k qty) | $0.48 | $0.45 | $0.62 | $0.75 | $1.45 |
Key Differentiators
- Tape & Reel packaging variant of PIC16C620A (vs PIC16C620A-20I/SO)
- Lower cost than PIC16C622 with same 18-SOIC footprint (vs PIC16C622AT-20I/SO)
- Lower cost than flash-based PIC16F628A (vs PIC16F628A-I/SO)
- Industrial temperature range with analog comparators (vs PIC16C620AT-20/SS)
Design Notes
Place a 0.1 µF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 14) and a 10 µF bulk capacitor on the same node. For OTP programming, MCLR/VPP must be driven to approximately 13 V during the programming pulse; provide a test pad or programming connector accessible during in-circuit programming. Brown-out reset is internally trimmed but designers should still validate cold-start behavior at 3.0 V VDD with a 20 MHz crystal, since low-voltage crystal startup is the most common failure mode for 20 MHz designs.
Route the crystal traces (OSC1/OSC2) as short and symmetric as possible, with the load capacitors placed within 2 mm of the respective oscillator pins. Keep the RA0/RA1 analog comparator traces away from switching signals like PWM outputs on RB4-RB7 to avoid coupling into the comparator reference. The exposed pad on the 18-SOIC is not present on this package variant, but for the SSOP variant ensure the thermal pad is soldered to a copper pour of at least 100 mm² for thermal relief at 20 MHz.
OTP memory cannot be erased or reprogrammed: a single bit error during programming bricks the part. Estimated: programming failures occur in approximately 1-3% of parts in high-volume production, so over-program by 3-5% to compensate. Do not confuse the -20I speed grade with the -04 (4 MHz) or -40 (40 MHz) speed grades - the suffix encodes the maximum oscillator frequency. The PIC16C620A is NOT a flash part; for in-field updates, select PIC16F628A-I/SO as a drop-in upgrade.
The analog comparators share pins RA0/RA1 with digital I/O; configure TRISA bits to disable digital output drivers on these pins when using comparator mode to prevent digital switching noise from corrupting the analog threshold. The programmable voltage reference (VR<3:0>) steps in 16 discrete levels; for fine threshold resolution, add an external resistor divider on a dedicated RA pin and use the comparator with an external reference.
Compliance Information
Compliance status not explicitly confirmed in the verified web data; RoHS and lead-free marking should be verified per the manufacturer datasheet and reel label before placing in RoHS-restricted designs. The -40C to +85C industrial temperature range does not imply AEC-Q100 automotive qualification.
