PIC16C558T-20E/SS - 8-Bit OTP MCU, 20MHz, 3.5KB | Microchip
MPN: PIC16C558T-20E/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.75 | $275.00 |
| 500 | $2.4 | $1,200.00 |
| 1,000 | $2.1 | $2,100.00 |
PIC16C558T-20E/SS Overview
An 8-bit microcontroller (MCU) is a small computing system on a single integrated circuit that combines a CPU, RAM, non-volatile program memory, and configurable I/O peripherals. PIC microcontrollers use a RISC (Reduced Instruction Set Computer) architecture with a Harvard memory structure, providing deterministic instruction execution in a single clock cycle for most instructions. PIC MCUs sit within the broader hierarchy of embedded microcontrollers, beneath microprocessors in complexity but above simple state machines in programmability.
Key features of the PIC16C558T-20E/SS include 13 digital I/O pins, a 20 MHz internal oscillator operating frequency at 5V, an 8-bit timer/counter, watchdog timer, power-on reset, brown-out detection, and an instruction set of 35 single-word instructions. The OTP program memory allows the device to be programmed once and retains the code permanently without the need for external program storage.
The PIC16C558 architecture employs a 14-bit instruction word with a 14-bit program memory bus, distinct from the 8-bit data bus. This dual-bus Harvard architecture enables simultaneous instruction fetch and data access, achieving near one-instruction-per-clock throughput. The device operates from 3.0V to 5.5V supply voltage and is fabricated using Microchip's proprietary CMOS process with low-power CMOS technology.
Typical applications include industrial control systems, automotive body electronics, sensor interfacing nodes, low-cost consumer appliances, and battery-powered embedded devices. The extended temperature range and OTP memory make it suitable for high-volume production where code is finalized and reprogramming is unnecessary.
When designing with this OTP device, ensure code is fully validated before programming since OTP cannot be erased or rewritten. Engineers should use the equivalent flash-based PIC16F558 for prototype development and validation, then transition to this OTP version for cost-optimized production runs.
This page synthesizes distributor pricing snapshots, same-brand Microchip drop-in alternatives, and practical design guidance not aggregated in any single manufacturer document, enabling faster sourcing and engineering decisions.
Drop-in alternatives for PIC16C558T-20E/SS — 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 PIC16C558T-20E/SS (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Watchdog Timer, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C558T-20/SS
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →PIC16C558-20E/SS
✅ Drop-In✓ In Stock
$2.53 / Unit
View Datasheet →PIC16C558-20I/SS
✅ Drop-In✓ In Stock
$2.15 / Unit
View Datasheet →PIC16C554T-20/SS
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC16C554T-04/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.14 / Unit
View Datasheet →PIC16C558T-20E/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC |
| Family | PIC16C Series |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 3.5 KB (2K x 14) |
| RAM Size | 128 bytes (128 x 8) |
| Maximum Clock Frequency | 20 MHz |
| Instruction Set Width | 14-bit |
| Number of I/O Pins | 13 |
| Supply Voltage Range | 3.0 V to 5.5 V |
| Operating Temperature Range | -40 C to +125 C (Extended, E grade) |
| Package | 20-SSOP (5.30 mm body width) |
| Mounting Type | Surface Mount |
| Timers | 1 x 8-bit Timer/Counter |
| Watchdog Timer | Yes |
| Peripherals | POR, Brown-out Reset, WDT |
| Packaging Form | Tape and Reel (T suffix) |
PIC16C558T-20E/SS Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 (analog input channel 0) |
| Pin 2 | RA1/AN1 — PORTA bit 1 (analog input channel 1) |
| Pin 3 | RA2/AN2 — PORTA bit 2 (analog input channel 2) |
| Pin 4 | RA3/AN3 — PORTA bit 3 (analog input channel 3 / VREF+) |
| Pin 5 | RA4/T0CKI — PORTA bit 4 (Timer 0 clock input) |
| Pin 6 | GND — Ground reference |
| Pin 7 | RB0/INT — PORTB bit 0 (external interrupt input) |
| Pin 8 | RB1 — PORTB bit 1 |
| Pin 9 | RB2 — PORTB bit 2 |
| Pin 10 | RB3 — PORTB bit 3 |
| Pin 11 | RB4 — PORTB bit 4 |
| Pin 12 | RB5 — PORTB bit 5 |
| Pin 13 | RB6 — PORTB bit 6 |
| Pin 14 | RB7 — PORTB bit 7 |
| Pin 15 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 16 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 17 | VSS — Ground reference |
| Pin 18 | VDD — Positive supply voltage (3.0V to 5.5V) |
| Pin 19 | VSS — Ground reference (secondary) |
| Pin 20 | MCLR/VPP — Master clear reset input / programming voltage |
Typical Applications
PIC16C558T-20E/SS is suitable for 6 applications: Industrial Sensor Interface Node, Automotive Body Electronics Control, Low-Cost Consumer Appliance Controller, Battery-Powered Remote Sensor Transmitter, HVAC Building Automation Sub-Node, Educational Embedded Development Platform.
Industrial Sensor Interface Node
The PIC16C558T-20E/SS fits sensor interface nodes because its 13 I/O pins comfortably accommodate multiple analog and digital sensor inputs while the 20 MHz clock delivers 5 MIPS throughput for real-time signal conditioning. The Extended -40C to +125C temperature grade suits factory floor thermal stress, and 128 bytes RAM is sufficient for transient sensor buffer storage. A typical circuit uses the 8-bit timer for periodic sampling, brown-out reset for power glitch immunity, and watchdog timer to recover from firmware lockup. The 3.5 KB OTP program memory holds complete UART/SPI driver stacks plus sensor calibration tables, eliminating external program storage. Designers should use the flash-equivalent PIC16F558 for field reconfiguration, then transition to the OTP part for high-volume deployment where code is locked.
Recommended
Automotive Body Electronics Control
The PIC16C558T-20E/SS targets automotive body modules such as lighting controllers, seat position monitors, and accessory multiplexers because the -40C to +125C extended grade handles under-hood and cabin thermal cycles. The 20 MHz core runs at 5V with deterministic single-cycle instructions, providing responsive PWM generation for motor drive signals. Its 13 I/O pins multiplex multiple low-speed switches and actuators, while the brown-out reset prevents erratic behavior during automotive cranking transients. The OTP memory prevents field tampering with calibration data, an advantage for OEM-locked modules. Note that for safety-critical subsystems (airbag, ABS) the PIC16C558 is not AEC-Q100 qualified and engineers should select a Q-graded alternative. As a cost-optimized body controller, this part excels in non-safety peripherals across vehicle platforms.
Recommended
Low-Cost Consumer Appliance Controller
In consumer appliances such as coffee makers, washing machine sub-controllers, and countertop food processors, the PIC16C558T-20E/SS provides just enough compute for simple state-machine-based control while minimizing BOM cost through OTP memory and minimal external components. The 3.5 KB OTP holds appliance-specific firmware plus user-interface lookup tables; 128 bytes RAM accommodates cycle counters and timing variables. The 20 MHz execution speed enables responsive button debouncing, LED multiplexed display refresh, and relay sequencing without perceivable latency. The brown-out reset protects against unreliable behavior during brown-out events on shared household wiring. For prototyping, the flash-equivalent PIC16F558 lets engineers iterate quickly, then production migrates to the OTP variant for under-$2 unit cost at 1k quantities, making this part a staple of cost-engineered consumer products.
Recommended
Battery-Powered Remote Sensor Transmitter
The PIC16C558T-20E/SS suits battery-powered remote sensor transmitters that wake periodically, take a measurement, transmit over RF or wireline, then return to sleep. The PIC16C CMOS process delivers low active current, and the brown-out reset prevents spurious wakes at low battery voltage. The 20 MHz clock enables fast sensor acquisition and RF packet assembly, minimizing active time and extending battery life. With 128 bytes RAM, the part buffers a single sensor sample and short packet payload without overflow. The 13 I/O pins drive an RF module chip-select, status LED, and a wake-up interrupt source. Engineers should add external sleep-current management (load switch or MOSFET) since the OTP part cannot run firmware updates to fix late-discovered sleep-mode bugs.
Recommended
HVAC Building Automation Sub-Node
Building automation sub-nodes such as damper actuators, fan speed controllers, and zone temperature regulators deploy the PIC16C558T-20E/SS as a distributed intelligence node. The 3.5 KB OTP holds a complete Modbus RTU slave or simple proprietary protocol stack, freeing the central controller from polling overhead. The 8-bit timer drives triac phase-angle control for AC loads, while the watchdog timer recovers from electrical noise-induced firmware lockups common in HVAC wiring. The 13 I/O pins accommodate triac optocouplers, zero-cross detect inputs, and a serial link to the central panel. The extended temperature grade handles plenum environments where ambient may exceed 70C. The OTP memory prevents unauthorized firmware modification in commercial installations, a security advantage for managed buildings.
Recommended
Educational Embedded Development Platform
The PIC16C558T-20E/SS appears in university embedded systems courses and electronics teaching labs as a representative 8-bit RISC microcontroller. Its simple 35-instruction set, 13 I/O pins, and clear peripheral block diagram make it pedagogically valuable for teaching register-level programming without ARM Cortex-M complexity. Students learn OTP programming workflow on a flash variant (PIC16F558), then graduate to OTP parts to understand production programming economics. The SSOP-20 footprint requires fine-pitch soldering practice, building surface-mount skills. The 20 MHz clock allows observation of instruction timing on an oscilloscope for hands-on learning of pipelined execution. The extended temperature grade allows lab experiments with thermal chambers to demonstrate semiconductor behavior. While newer curricula emphasize 32-bit parts, the PIC16C558 remains a low-cost entry point for fundamentals.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C558T-20E/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C558T-20/SS | PIC16C558-20E/SS | PIC16C558-20I/SS | PIC16C554T-20/SS | PIC16C554T-04/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same |
| Program Memory | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP | 0.875 KB OTP | 0.875 KB OTP |
| RAM | 128 B | 128 B | 128 B | 128 B | 80 B | 80 B |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 4 MHz |
| I/O Pins | 13 | 13 | 13 | 13 | 13 | 13 |
| Temperature Grade | Extended (-40C to +125C) | Industrial (-40C to +85C) | Extended (-40C to +125C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) |
| Packaging Form | Tape and Reel | Tape and Reel | Tube | Tube | Tape and Reel | Tape and Reel |
Key Differentiators
- Extended temperature grade up to +125C (vs PIC16C558T-20/SS)
- Tape and Reel packaging for high-volume SMT (vs PIC16C558-20E/SS)
- Higher program memory capacity versus PIC16C554 family (vs PIC16C554T-20/SS)
Design Notes
The PIC16C558T-20E/SS operates from 3.0V to 5.5V with brown-out reset protection. Add a 100 nF decoupling capacitor as close as practical to the VDD pin (pin 18) and a bulk 10 uF tantalum or ceramic on the supply rail. The brown-out voltage is typically ~4.0V at 5V operation; if your supply can dip below this threshold, ensure firmware can survive unexpected resets without latching outputs in an unsafe state. Estimated: typical active current at 20 MHz and 5V is approximately 2-5 mA, dominated by clock tree and I/O switching.
OTP (One-Time Programmable) memory cannot be erased. Always develop and validate firmware on the flash-equivalent PIC16F558-I/SS, then commit production code to PIC16C558T-20E/SS only after full validation. Budget for programming time during manufacturing: OTP programming requires elevated VPP on the MCLR pin (typically 13V) and per-device programming time on the order of seconds. A programming failure on an OTP device destroys the part, so use Microchip-approved programmers with verified socket adapters.
For SSOP-20 layout, use a fine-pitch land pattern with 0.65 mm pitch and a thermal relief spoke pattern on the GND pad. Place the decoupling capacitor within 3 mm of the VDD pin to minimize supply inductance. Keep crystal or resonator traces short (under 10 mm) and symmetric between OSC1 and OSC2 to avoid clock skew. If using an external clock source, route it away from switching signals to reduce jitter. The MCLR pin benefits from a 10 kohm pull-up to VDD and a 100 nF cap to ground for noise immunity.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status not explicitly confirmed in the provided web data; consult Microchip product compliance documentation. AEC-Q100 not qualified - this is a commercial/industrial grade part, not automotive qualified. For AEC-Q100 requirements, choose a Q-graded alternative.