PIC16C620AT-04/SO - 8-bit 4MHz 18SOIC OTP MCU | PIC16C620A Series
MPN: PIC16C620AT-04/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.93 | $1.93 |
| 10 | $1.74 | $17.40 |
| 100 | $1.45 | $145.00 |
| 500 | $1.21 | $605.00 |
| 1,000 | $0.93 | $930.00 |
PIC16C620AT-04/SO Overview
An 8-bit microcontroller is a single-chip computer built around an 8-bit data path, optimized for deterministic, low-cost embedded control. The PIC architecture uses a Harvard design with separate program and data buses and a reduced instruction set (RISC) of only 35 single-word instructions. The 'C' series is the OTP (one-time programmable) variant of the original PIC16C family, positioned between the older windowed UV-erasable parts and the later Flash-based PIC16F family in the Microchip product hierarchy. LDO regulators and supervisor ICs typically surround such MCUs to provide clean 5V rails and brown-out reset.
The PIC16C620AT-04/SO runs from 3.0V to 5.5V, supports an instruction cycle time of 200 ns at 4 MHz, and offers programmable code protection. The 'A' silicon revision adds brown-out detect (BOR), an internal RC oscillator option, and improved ADC accuracy versus the original PIC16C620. The 'T' suffix indicates tape-and-reel packaging for high-volume assembly, and 'SO' specifies the 7.50 mm body-width 18-SOIC surface-mount package. Peripherals include a 16-bit timer/counter with 3-bit prescaler, an 8-bit timer/counter, a synchronous serial port (SSP) supporting an SPI-master interface, and two analog comparators with programmable reference.
The PIC16C620A architecture combines a RISC CPU core, EPROM program memory, and rich analog peripherals in a compact footprint, enabling standalone control loops without external logic. The on-chip comparators and ADC make it well suited for sensor conditioning, while the interrupt controller with 7 sources supports responsive pre-emptive task handling. Static CMOS design with software-selectable oscillator options (RC, XT, LP, HS) allows engineers to trade speed against current consumption.
Typical applications include battery chargers, SMPS control loops, sensor signal conditioning, low-cost motor control, security and alarm panels, and consumer appliance interfaces. The wide supply range, integrated analog, and small package also suit industrial instrumentation and automotive body electronics where the OTP/Flash migration path preserves firmware investments.
When designing with the PIC16C620AT-04/SO, choose an external clock frequency that matches the oscillator mode (XT for 4 MHz) and ensure Vdd decoupling with a 100 nF ceramic plus 10 uF bulk capacitor within 5 mm of the IC. Plan OTP programming during prototyping because OTP parts cannot be reprogrammed; budget for the PIC16F628A as a Flash-based migration path for production.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes that complement the manufacturer datasheet for the PIC16C620AT-04/SO.
Drop-in alternatives for PIC16C620AT-04/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-04/SO (same form factor and footprint) — differing in Program Memory Size, Operating Temperature Range, Package, Program Memory Type, RAM Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C620A-04/SO
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC16C620AT-04I/SO
✅ Drop-In✓ In Stock
$1.16 / Unit
View Datasheet →PIC16F628A-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F628AT-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C620AT-04/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Instruction Set | 35 single-word instructions |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 896 bytes (512 x 14) |
| RAM | 96 bytes |
| EEPROM Data Memory | None (0 bytes) |
| Maximum CPU Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns at 4 MHz |
| Supply Voltage Range | 3.0 V to 5.5 V |
| I/O Pins | 13 |
| ADC | 8-bit, 5 channels |
| Comparators | 2 analog comparators with programmable reference |
| Timers | One 16-bit + one 8-bit timer/counter |
| Watchdog Timer | Yes (WDT with dedicated RC oscillator) |
| Brown-Out Detect | Yes (silicon 'A' revision) |
| Oscillator Modes | RC, XT, LP, HS (external oscillator required for /SO variant) |
| Operating Temperature Range | 0 C to +70 C (commercial, 'no 'I'') |
| Package | 18-SOIC (SO), 7.50 mm body width |
| Mounting Type | Surface Mount |
| Lead Finish | Matte Tin (Pb-free) |
PIC16C620AT-04/SO Pin Configuration
| Pin 1 | MCLR/Vpp — Master clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — Port A bit 0 / ADC input 0 |
| Pin 3 | RA1/AN1 — Port A bit 1 / ADC input 1 |
| Pin 4 | RA2/AN2/CVREF — Port A bit 2 / ADC input 2 / comparator voltage reference |
| Pin 5 | RA3/AN3/VREF+ — Port A bit 3 / ADC input 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — Port A bit 4 (open-drain) / Timer 0 clock input |
| Pin 7 | RA5/SS/AN4 — Port A bit 5 / SSP slave select / ADC input 4 |
| Pin 8 | Vss — Ground reference |
| Pin 9 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 10 | OSC2/CLKOUT — Oscillator crystal output / clock output (Fosc/4) |
| Pin 11 | RB0/INT — Port B bit 0 / external interrupt |
| Pin 12 | RB1 — Port B bit 1 |
| Pin 13 | RB2 — Port B bit 2 |
| Pin 14 | RB3/PGM — Port B bit 3 / low-voltage programming |
| Pin 15 | RB4 — Port B bit 4 |
| Pin 16 | RB5 — Port B bit 5 |
| Pin 17 | RB6/PGC — Port B bit 6 / ICSP clock |
| Pin 18 | RB7/PGD — Port B bit 7 / ICSP data |
Typical Applications
PIC16C620AT-04/SO is suitable for 6 applications: Battery Charger Control, Sensor Signal Conditioning, Low-Cost Motor Control, Security and Alarm Panels, Industrial Instrumentation, Consumer Appliance Interfaces.
Battery Charger Control
The PIC16C620AT-04/SO fits battery charger controllers because it combines the 8-bit ADC for voltage and current sensing, two analog comparators for charge-state thresholds, and 13 I/O pins for relay/MOSFET switching. At 4 MHz it executes the 200 ns charge-loop in a single cycle, allowing accurate CC/CV control of NiCd, NiMH, and SLA packs at charger rates up to several amps. Its integrated brown-out detect prevents re-entering charging mode below 4 V, protecting deeply discharged cells. Compared with pure analog charger ICs, the PIC16C620AT-04/SO adds programmable charge profiles (trickle, fast, top-off, equalization) stored in OTP. For new designs the Flash-based PIC16F628A is the recommended migration because field-updatable firmware is increasingly expected in lithium chargers.
Recommended
Sensor Signal Conditioning
For sensor signal conditioning, the PIC16C620AT-04/SO's on-chip 5-channel 8-bit ADC and two analog comparators handle resistive bridges, thermistors, and photodiodes without external amplifiers. The RISC core runs linearization math at 4 MIPS, fast enough for closed-loop temperature, pressure, or flow control at sub-100 Hz bandwidths. Its 13 I/O pins drive indicator displays, optocouplers, or 4-20 mA loops directly. Brown-out detect ensures the controller restarts cleanly after brown-outs on long sensor cables. Engineers typically pair this MCU with an op-amp front-end for sensor gain and a precision voltage reference such as the MCP1541 for absolute accuracy beyond the ADC's 8-bit resolution.
Recommended
Low-Cost Motor Control
The PIC16C620AT-04/SO drives small DC motors, solenoids, and stepper motors through its 25 mA source/sink I/O, with one timer/counter generating PWM signals and another handling back-EMF or tachometer feedback. The two on-chip comparators detect zero-crossings for triac or back-EMF commutation, eliminating external zero-cross circuits in AC induction or brushed DC drives. At 4 MHz, a 2 kHz PWM resolution is achievable for fine-grained speed control. The 18-SOIC footprint allows the MCU to sit adjacent to H-bridge drivers such as the L293D or DRV8871, reducing PCB area and EMI. For BLDC upgrades, migrate to PIC16F628A with its enhanced PWM module.
Recommended
Security and Alarm Panels
Security panels benefit from the PIC16C620AT-04/SO because its 5 ADC inputs monitor multiple zones (door, window, PIR, smoke) and the 13 I/O pins drive sirens, keypads, and dialer interfaces. The on-chip watchdog timer detects firmware lock-up and resets the system, while the brown-out detect handles power-loss events that intruders often trigger. Code protection on the OTP memory prevents firmware cloning, important for alarm OEMs. The 4 MHz clock rate is sufficient for periodic polling of sensor zones within 50 ms latency. Designers typically add a piezo driver and a relay output, with the MCU running from a backup battery through an MCP1700 LDO.
Recommended
Industrial Instrumentation
In industrial panels and instrumentation, the PIC16C620AT-04/SO provides local control logic between sensors and a host PLC, reading 4-20 mA loops via shunt resistor + ADC and driving 7-segment displays or character LCDs. The industrial temperature variant PIC16C620AT-04I/SO covers -40C to +85C environments such as factory floors and outdoor enclosures. The 4 MHz RISC core delivers deterministic timing for alarm-trip logic and watchdog supervision, while the on-chip comparators implement fast over-current or over-voltage thresholds without external comparators. The wide 3.0-5.5V supply tolerates loosely regulated industrial rails after a TVS and bulk cap front-end.
Recommended
Consumer Appliance Interfaces
White goods and consumer appliances use the PIC16C620AT-04/SO as the user-interface controller that scans key matrices, drives LED or VFD displays, and communicates with the main appliance MCU via SPI. The 13 I/O pins handle 12-key matrices plus display enable, and the on-chip comparators detect line-voltage zero crossings for triac-fired heater or motor loads. Its 3.0-5.5V range works directly off rectified mains after dropping through an MCP1700 LDO. OTP storage locks the user-interface firmware to the appliance model, while consumers benefit from a low BOM cost and small 18-SOIC PCB footprint. Migrating to PIC16F628A is straightforward for firmware reuse.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C620AT-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C620A-04/SO | PIC16C620AT-04I/SO | PIC16F628A-I/SO | PIC16F628AT-I/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC (SO) | 18-SOIC (SO) - same | 18-SOIC (SO) - same | 18-SOIC (SO) - same | 18-SOIC (SO) - same |
| Program Memory | 896 B OTP (512 x 14) | 896 B OTP (512 x 14) | 896 B OTP (512 x 14) | 2048 x 14 Flash (4x larger) | 2048 x 14 Flash (4x larger) |
| RAM | 96 B | 96 B | 96 B | 224 B | 224 B |
| Maximum CPU Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz |
| Operating Temperature | 0 C to +70 C | 0 C to +70 C | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) |
| ADC | 8-bit, 5 channels | 8-bit, 5 channels | 8-bit, 5 channels | 10-bit, 7 channels | 10-bit, 7 channels |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | Flash (field upgradeable) | Flash (field upgradeable) |
| Packaging Form | Tape & Reel (T-suffix) | Tube (no T-suffix) | Tape & Reel | Tube | Tape & Reel |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Active | Active |
Key Differentiators
- On-chip dual analog comparators with programmable voltage reference (vs PIC16F628A-I/SO)
- Brown-out detect on silicon 'A' revision (vs PIC16C620 (original silicon))
- Lower unit cost compared to Flash-based PIC16F628A (vs PIC16F628A-I/SO)
- Standard 18-SOIC footprint compatible with Flash-based migration path (vs PIC16F628A-I/SO)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of the Vdd pin and a 10 uF bulk tantalum or aluminum capacitor near the IC to suppress digital switching transients. Keep the decoupling loop area small to minimize inductance. Per Microchip's PIC16C62X datasheet, additional bulk capacitance may be required for ADC accuracy if the analog Vdd is shared with digital Vdd; consider a ferrite bead plus a separate 100 nF analog-side capacitor.
Route the external crystal traces (OSC1/OSC2) short and symmetric, with a ground guard trace beneath the crystal to reduce EMI coupling. Keep switching regulator or relay drive traces away from the oscillator and analog ADC inputs (RA0-RA5) to avoid clock and ADC corruption. The 18-SOIC package has a thermal pad-less bottom, so no exposed pad is required, but ground flood under the IC improves both EMI and thermal performance.
OTP memory cannot be reprogrammed: plan programming strategy carefully during prototype bring-up. Configure brown-out detect (BOR) before relying on reset behavior - the 'A' silicon revision enables BOR by configuration bit, but the original 'A' revision defaults are different. Confirm the MCLR pin has a 10 kohm pull-up to Vdd and a 100 nF cap to ground for proper reset; omitting the cap can cause false resets from EMI. Do not apply Vpp (13V) to MCLR during normal operation - only during OTP programming.
Operating voltage is 3.0 V to 5.5 V; pick a regulator with low dropout to handle worst-case input dips. For USB-powered designs, use an MCP1700-3302 (3.3V LDO) or MCP1700-5002 (5V LDO) with a 1 uF ceramic output capacitor. Estimated: at 4 MHz and 5 V, IDD is typically 2-5 mA in active mode and <1 uA in sleep; verify with the datasheet's DC characteristics table for the exact 'B' notation in your silicon revision.
Compliance Information
Lead-free matte-tin finish confirmed by Microchip product page. RoHS/REACH compliance status is not confirmed in the provided web data; consult Microchip's product environmental compliance page for official certificate. Not AEC-Q100 qualified.
