PIC16C620AT-20/SO - 8-bit OTP MCU, 20 MHz, 896B | Microchip
MPN: PIC16C620AT-20/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.43 | $3.43 |
| 10 | $3.08 | $30.80 |
| 100 | $2.74 | $274.00 |
| 500 | $2.42 | $1,210.00 |
| 1,000 | $2.18 | $2,180.00 |
PIC16C620AT-20/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that combines a CPU, non-volatile program memory, working RAM, and peripheral interfaces on one piece of silicon. Within the broader taxonomy, the PIC16C620A belongs to the OTP-MCU family -> 8-bit PIC microcontrollers -> PICmicro family -> Microchip 8-bit MCU portfolio -> embedded microcontrollers -> semiconductors. Its RISC Harvard architecture and 35-instruction instruction set make it well suited to deterministic real-time control where predictable interrupt latency matters more than raw throughput.
Key features include a hardware USART, 8-bit ADC with 4-channel mux, two 8-bit timers (Timer0/Timer2) plus one 16-bit timer (Timer1), on-chip watchdog timer with its own on-chip RC oscillator, and a programmable code protection mechanism that secures the OTP image. Brown-out-reset (BOR) circuitry and power-on-reset (POR) are integrated, simplifying external reset-tree design. The PIC16C620A also exposes an ICD (In-Circuit Debug) interface for MPLAB ICD 2/3 programming during development.
Architecturally, the PIC16C620A separates program and data buses (Harvard), uses a 14-bit instruction word, and pipelines fetch-and-execute so most instructions complete in one cycle. The 20 MHz Fosc yields a 5 MIPS peak instruction rate; typical applications run at 4 MHz / 1 MIPS for low-power or EMI-sensitive use. CMOS process technology keeps quiescent current in the low milliamp range, and the sleep mode drops consumption to under 1 uA for battery-friendly duty-cycled designs.
Typical applications include low-cost consumer appliances, security keypads and access-control panels, small motor-control boards, IR remote receivers, and battery-backed sensor interfaces. The 13-I/O budget is sufficient for matrix keypads, LED indicators, and a serial link to a host controller.
When designing, place a 100 nF decoupling capacitor within 5 mm of the VDD pin, reserve a 4-10 MHz crystal footprint (or use the internal RC mode for BOM reduction), and never connect MCLR floating - tie it to VDD through a 10 kohm resistor or drive it with the host. Designers upgrading older PIC16C5X designs will appreciate the software-compatible instruction set.
This page synthesizes distributor pricing, drop-in same-package alternatives (PIC16C620A, PIC16C620, PIC16C621A, PIC16C622A families), and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C620AT-20/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-20/SO (same form factor and footprint) — differing in Operating Temperature, Program Memory Size, Instruction Cycle Time, RoHS Status, Maximum Clock Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C620A-20/SO
✅ Drop-In✓ In Stock
$2.04 / Unit
View Datasheet →PIC16C620-20/SO
✅ Drop-In✓ In Stock
$2.52 / Unit
PIC16C620A-04/SO
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC16C620A-40/SO
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →PIC16C621AT-20I/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.3 / Unit
View Datasheet →PIC16C622AT-20I/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.82 / Unit
View Datasheet →PIC16C620AT-20/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit RISC (Harvard) |
| Family | PIC16C Series (PIC16C620A) |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 896 B (512 x 14) |
| RAM Size | 96 B |
| EEPROM Size | None (external support only) |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle | 200 ns |
| Operating Voltage (Vdd) | 3.0 V to 5.5 V |
| I/O Pins | 13 |
| Timers | 1 x 8-bit, 1 x 16-bit |
| ADC | None (PIC16C620A has no ADC) |
| Package | 18-pin SOIC (SO) 0.295" (7.50 mm) width |
| Operating Temperature | 0 C to +70 C (commercial) |
| Mounting Type | Surface Mount |
| RoHS Status | Non-compliant (OTP PIC16C family is typically non-RoHS) |
| Lead-Free | No (leaded OTP windowed/standard) |
| Watchdog Timer | Yes (with dedicated on-chip RC oscillator) |
| Brown-Out Reset | Yes |
| In-Circuit Debug | Yes (MPLAB ICD 2/3) |
| ICSP (In-Circuit Serial Programming) | Yes |
PIC16C620AT-20/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 3 | RA4/T0CKI — Bidirectional I/O port A bit 4 / Timer0 clock input |
| Pin 4 | MCLR/VPP — Master Clear (Reset) input / Programming voltage |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O port B bit 0 / External interrupt |
| 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 (interrupt-on-change) |
| Pin 11 | RB5 — Bidirectional I/O port B bit 5 (interrupt-on-change) |
| Pin 12 | RB6 — Bidirectional I/O port B bit 6 (interrupt-on-change / ICSP clock) |
| Pin 13 | RB7 — Bidirectional I/O port B bit 7 (interrupt-on-change / ICSP data) |
| Pin 14 | VDD — Positive supply voltage (3.0 V to 5.5 V) |
| Pin 15 | OSC2/CLKOUT — Oscillator crystal output / Clock output |
| Pin 16 | OSC1/CLKIN — Oscillator crystal input / External clock input |
| Pin 17 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 18 | RA1 — Bidirectional I/O port A bit 1 |
Typical Applications
PIC16C620AT-20/SO is suitable for 6 applications: Consumer Appliance Control Board, Security Keypad and Access Control, Small Motor-Control Board (DC/Fan), IR Remote Receiver Decoder, Battery-Backed Sensor Interface, Industrial 5V Logic Replacement.
Consumer Appliance Control Board
The PIC16C620AT-20/SO fits consumer appliance control boards (washing machines, dishwashers, microwave ovens) where mature OTP firmware drives relays, triacs, and LED indicators at lowest unit cost. Its 13 I/O pins directly drive a 4x4 keypad matrix with room for status LEDs and a UART link to the main inverter board, while the integrated watchdog timer with its own on-chip RC oscillator ensures the controller recovers from EMI-induced lockups in motor-noise environments. The 20 MHz / 5 MIPS throughput handles timing-critical zero-crossing triac control at 50/60 Hz line frequencies. Compared to switching to a flash MCU, OTP is acceptable here because firmware is finalized at production launch and the 18-pin SOIC footprint survives multiple appliance generations.
Recommended
Security Keypad and Access Control
The PIC16C620AT-20/SO suits security keypads and access-control panels because its 13 I/O pins can scan a 3x4 or 4x4 matrix keypad, drive a piezo buzzer, interface an EEPROM for credential storage, and communicate with a host controller over UART. Brown-out-reset and the watchdog timer with on-chip RC oscillator prevent lockup-induced security bypass, while the 200 ns instruction cycle debounces key presses and runs small finite-state machines in real time. The 896 B OTP holds the access-control finite-state machine plus a custom encryption routine, and the 96 B RAM stores the current user entry buffer.
Recommended
Small Motor-Control Board (DC/Fan)
The PIC16C620AT-20/SO drives small brushed-DC motors and fan-speed controllers in 5V/12V embedded designs. The 16-bit Timer1 captures tachometer feedback from a Hall sensor or back-EMF, while the 8-bit Timer2 generates the PWM output that drives a MOSFET gate driver through one of the 13 I/O pins. The 5 MIPS instruction throughput maintains a tight PID loop at 1 kHz update rate without DSP overhead. The 3.0-5.5 V supply range works directly from a 5 V regulator, and the 18-pin SOIC keeps the board footprint under 10 mm wide.
Recommended
IR Remote Receiver Decoder
The PIC16C620AT-20/SO decodes consumer IR remote protocols (RC-5, NEC, Sony SIRC) for set-top boxes, AV receivers, and smart-home bridges. Its 16-bit Timer1 captures the 38 kHz carrier envelope measured by an external IR receiver module, and the 5 MIPS throughput handles bit-level decoding in real time without missing pulses. The 96 B RAM buffers the received frame for protocol-stack parsing, and the USART transmits decoded commands to the host CPU. The 13 I/O count accommodates IR input, status LED, learning-mode button, and UART output.
Recommended
Battery-Backed Sensor Interface
The PIC16C620AT-20/SO reads low-bandwidth analog sensors through an external ADC and forwards readings to a host via UART or I2C bit-banging, with sleep current under 1 uA for battery-backed sensor nodes. Its integrated watchdog timer with on-chip RC oscillator wakes the controller from sleep without external components, and the BOR circuit prevents corrupted EEPROM writes during battery brown-out. The 8-bit RISC core is more than sufficient for sensor linearization and threshold-alarm logic at 1 Hz sample rates, while OTP keeps unit cost minimal for disposable/wide-deploy sensor networks.
Recommended
Industrial 5V Logic Replacement
The PIC16C620AT-20/SO is a drop-in 5V-logic replacement for aging PIC16C5X designs in legacy industrial equipment where field-reprogramming is undesirable and OTP firmware is acceptable. Its instruction-set compatibility with the PIC16C5X family allows existing assembly code to be recompiled with minimal changes, and its 5.5 V absolute-maximum VDD tolerates industrial 5 V supply tolerance. The 18-pin SOIC footprint matches the previous-generation land pattern, so no PCB rework is required. The integrated watchdog timer with on-chip RC oscillator eliminates the external WDT supervisor that older PIC16C5X designs required.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C620AT-20/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C620A-20/SO | PIC16C620-20/SO | PIC16C620A-04/SO | PIC16C620A-40/SO | PIC16C621AT-20I/SO |
|---|---|---|---|---|---|---|
| Package | 18-SOIC (SO) 0.295" / 7.50 mm | 18-SOIC (SO) - same | 18-SOIC (SO) - same | 18-SOIC (SO) - same | 18-SOIC (SO) - same | 18-SOIC (SO) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 4 MHz | 40 MHz | 20 MHz |
| Program Memory | 896 B OTP | 896 B OTP | 896 B OTP | 896 B OTP | 896 B OTP | 1 K OTP |
| RAM | 96 B | 96 B | 96 B | 96 B | 96 B | 128 B |
| I/O Pins | 13 | 13 | 13 | 13 | 13 | 13 |
| 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 | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
| Operating Temperature | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | -40 C to +85 C (industrial) |
| Special Features | WDT, BOR, ICSP, ICD | WDT, BOR, ICSP, ICD (identical) | WDT, BOR, ICSP (no ICD) | WDT, BOR, ICSP, ICD (identical) | WDT, BOR, ICSP, ICD (identical) | WDT, BOR, ICSP, ICD + analog comparator |
| Lifecycle | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Drop-in same-die replacement via tube packaging variant (vs PIC16C620A-20/SO)
- Higher 40 MHz upgrade path in same 18-SOIC footprint (vs PIC16C620A-40/SO)
- Functional upgrade to PIC16C621A adds analog comparator and more memory (vs PIC16C621AT-20I/SO)
Design Notes
Place a 100 nF decoupling capacitor (ceramic X7R) within 5 mm of the VDD pin (pin 14) and a second 10-100 uF bulk capacitor near the supply input. The PIC16C620AT-20/SO draws typically < 15 mA active at 20 MHz and 5 V, so a simple 78L05 or LDO is sufficient. The integrated brown-out-reset (BOR) circuit holds the CPU in reset when VDD falls below the programmable threshold; configure the BOR voltage in the configuration word to match your rail tolerance. Estimated power: P(active) ~= Vdd * I_dd ~= 5 V * 15 mA = 75 mW typical; P(sleep) < 5 uW at 3 V.
Route the crystal traces (OSC1/OSC2, pins 15-16) as short, symmetric loops and guard them with a ground pour to prevent crosstalk. Place the crystal within 5 mm of the MCU and keep clock traces away from switching signals and I/O edges. For EMI-sensitive applications, add a 4-resistor termination network on long signal runs. The MCLR pin (pin 4) must NOT be left floating - tie it to VDD through a 10 kohm resistor or drive it with the host controller. A 100 nF cap from MCLR to ground improves ESD immunity.
Three common pitfalls when designing with PIC16C620AT-20/SO: (1) PIC16C620A has NO on-chip ADC - if your design needs analog inputs, add an external MCP3002/MCP3202 SPI ADC or upgrade to PIC16C621A/PIC16C622A which adds analog comparators; (2) the OTP program memory can ONLY be programmed once - budget a second engineering sample run for firmware revisions; (3) PORTB internal weak pull-ups must be enabled in software (RBPU bit cleared) and only PORTB pins support them - PORTA pins float unless externally pulled. Also note that the 96-byte RAM is shared with the stack, so deep recursion will crash the controller.
The 18-pin SOIC package has a thermal resistance theta_JA of approximately 100 C/W (standard SOIC) and 80 C/W (exposed-pad variants, if applicable). At full-load operation (5 V, 20 MHz, all I/O switching), worst-case power dissipation is approximately 250 mW, giving a junction temperature rise of ~25 C above ambient. For commercial 0-70 C operation, derate above 45 C ambient if the device drives all 13 I/O pins at maximum source/sink current simultaneously. The integrated thermal shutdown does NOT exist on PIC16C620A - rely on the watchdog timer for fault recovery instead.
Compliance Information
PIC16C620AT-20/SO is a legacy OTP-MCU that uses lead-based solder terminations per industry convention for the PIC16C family. New designs should use flash-based PIC16F630-I/SL family which is RoHS compliant. Per Microchip product environmental compliance, the PIC16C620A family is not RoHS compliant but is REACH SVHC compliant.
