PIC16C54AT-04E/SO - 8-Bit 4MHz OTP MCU 768B | 18-SOIC
MPN: PIC16C54AT-04E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.1 | $31.00 |
| 100 | $2.78 | $278.00 |
| 500 | $2.46 | $1,230.00 |
| 1,000 | $2.2 | $2,200.00 |
PIC16C54AT-04E/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer whose data path, registers, and ALU operate on 8 bits at a time. The PIC16C5X family sits at the entry-level tier of Microchip's 8-bit portfolio, below the mid-range PIC16 and enhanced mid-range families. These baseline parts use a 12-bit-wide instruction word and a RISC-like Harvard architecture, where program and data memories have separate buses. The 8-bit MCU category belongs to the broader microcontroller hierarchy, which itself falls under embedded processors, integrated circuits, and finally semiconductors. OTP (One-Time Programmable) memory is a non-volatile technology that can be written once by the user, distinguishing the C5X family from flash-based PIC16F parts and from windowed EPROM C5X parts that allow erasure via UV light.
Key features include a single-cycle 1 microsecond instruction cycle at 4 MHz, a 33-word instruction set where all instructions execute in one cycle except program branches (two cycles), and a 12 I/O pin count with independent direction control. The device also provides a watchdog timer for runaway code recovery, a power-on reset circuit, and an operating voltage range of 4.5 V to 5.5 V. The 'A' silicon revision improves upon the original PIC16C54 by adding oscillator selection bits and refined brown-out behavior.
Architecturally, the PIC16C5X uses a two-stage pipeline overlapped with instruction fetch, so most instructions appear to execute in a single cycle. The 12-bit instruction width yields 2:1 code density compared to typical 8-bit MCUs of its era, and the symmetrical instruction set reduces development time. The OTP program memory is written using Microchip's serial programming protocol via the RB6/RB7 pins.
Typical applications include low-cost embedded control nodes, appliance control boards, automotive body electronics subsystems, simple sensor interface modules, and hobby/educational microcontroller projects where legacy code bases already target the PIC16C5X instruction set. Designers transitioning new designs to the PIC16F54 are advised to verify peripheral compatibility, as the F54 family uses flash memory and a slightly different configuration word layout.
When designing with this part, remember that OTP parts cannot be reprogrammed; budget for a small engineering rework loop or use the PIC16C54A-04E/SO equivalent windowed version for prototype bring-up. The 18-SOIC package has a thermal resistance in the typical 80-100 C/W range for small-outline SO packages, so derate output current if the device will be operated near maximum temperature.
This page synthesizes distributor stock, drop-in same-package alternatives, and practical engineering design notes not aggregated in the manufacturer datasheet.
Drop-in alternatives for PIC16C54AT-04E/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 PIC16C54AT-04E/SO (same form factor and footprint) — differing in RoHS Status, Watchdog Timer, Operating Temperature, Package, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C54A-04E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C54A-20I/SO
✅ Drop-In✓ In Stock
$1.15 / Unit
View Datasheet →PIC16C54A-20/SO
✅ Drop-In✓ In Stock
$1.4 / Unit
View Datasheet →PIC16C54A-20I/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.51 / Unit
View Datasheet →PIC16C54A-20I/P
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.38 / Unit
View Datasheet →PIC16C54-10I/P
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16C54AT-04E/SO Maximum Ratings & Electrical Characteristics
| Family | PIC16C5X (PIC16C54A) |
| Core | 8-bit PIC RISC |
| Instruction Set Architecture | 12-bit wide, 33 single-word instructions |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle | 1 us at 4 MHz |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 768 bytes (512 x 12-bit words) |
| Data RAM | 25 x 8 bytes |
| I/O Pins | 12 |
| Supply Voltage | 4.5 V to 5.5 V |
| Operating Temperature | -40C to +125C (E suffix = Extended) |
| Package | 18-SOIC (0.295", 7.50 mm width) |
| Mounting Type | Surface Mount |
| Watchdog Timer | Yes (on-chip, software-enabled) |
| Power-On Reset | Yes |
| Brown-Out Detect | Yes |
| Lead-Free / RoHS | Lead-free finish (verify per lot) |
PIC16C54AT-04E/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O pin, PORTA bit 2 |
| Pin 2 | RA3 — Bidirectional I/O pin, PORTA bit 3 |
| Pin 3 | RA4/T0CKI — Bidirectional I/O pin / Timer0 clock input (open-drain output) |
| Pin 4 | MCLR/VPP — Master Clear (reset) input / Programming voltage input |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O pin / External interrupt input |
| Pin 7 | RB1 — Bidirectional I/O pin, PORTB bit 1 |
| Pin 8 | RB2 — Bidirectional I/O pin, PORTB bit 2 |
| Pin 9 | RB3 — Bidirectional I/O pin, PORTB bit 3 |
| Pin 10 | RB4 — Bidirectional I/O pin, PORTB bit 4 |
| Pin 11 | RB5 — Bidirectional I/O pin, PORTB bit 5 |
| Pin 12 | RB6 — Bidirectional I/O pin / Serial programming clock |
| Pin 13 | RB7 — Bidirectional I/O pin / Serial programming data |
| Pin 14 | VDD — Positive supply voltage (4.5 V to 5.5 V) |
| Pin 15 | OSC2/CLKOUT — Oscillator crystal output / Clock out (Fosc/4) |
| Pin 16 | OSC1/CLKIN — Oscillator crystal input / External clock input |
| Pin 17 | RA0 — Bidirectional I/O pin, PORTA bit 0 |
| Pin 18 | RA1 — Bidirectional I/O pin, PORTA bit 1 |
Typical Applications
PIC16C54AT-04E/SO is suitable for 6 applications: Low-Cost Embedded Control Node, Appliance Control Board, Automotive Body Electronics Subsystem, Simple Sensor Interface Module, Hobby and Educational Microcontroller Project, Legacy Industrial Controller Card.
Low-Cost Embedded Control Node
The PIC16C54AT-04E/SO fits low-cost embedded control nodes where a minimal 8-bit MCU drives a handful of relays, LEDs, or switches. Its 33-instruction baseline RISC core, 4 MHz clock, and 1 us instruction time deliver sufficient throughput for scanning inputs and updating outputs in cycle times of a few milliseconds. OTP memory prevents firmware readback, an advantage when IP control firmware ships in volume and reverse-engineering risk must be minimized. The 18-SOIC package reflows cleanly on standard SMT lines.
Recommended
Appliance Control Board
The PIC16C54AT-04E/SO is well suited to appliance control boards for washing machines, dishwashers, and small kitchen appliances where cost dominates the BOM. The 12 I/O pins directly drive segment LEDs, keypads, and triac-control optocouplers without external glue logic. The on-chip watchdog timer and brown-out reset provide field reliability against supply brown-outs common in inductive motor environments. OTP memory locks the firmware at production, preventing warranty-period tampering with safety logic.
Recommended
Automotive Body Electronics Subsystem
The PIC16C54AT-04E/SO serves automotive body-electronics modules such as interior lighting controllers, simple door-lock nodes, and seat-position switches where the extended -40C to +125C temperature grade ('E' suffix) is mandatory. The 5 V supply range tolerates automotive cranking transients with adequate bulk capacitance on VDD. Its small 18-SOIC footprint fits within tight wiring-harness cluster geometries, and the 4 MHz core cycles fast enough for debouncing switch inputs and driving LED PWM at low duty cycles. OTP security is valuable for OEM-proprietary logic.
Recommended
Simple Sensor Interface Module
The PIC16C54AT-04E/SO operates as a simple sensor interface module that reads a thermistor, photocell, or contact closure and asserts a digital output. With 25 bytes of RAM and 12 I/O pins, the device can bit-bang resistive sensor bridges, drive a status LED, and stream serial debug on a spare pin. The 768-byte OTP program memory is enough for a state-machine-style sensor reader with calibration constants baked into the firmware image. Industrial temperature grade supports outdoor or under-hood installations.
Recommended
Hobby and Educational Microcontroller Project
The PIC16C54AT-04E/SO is a common target for hobby and educational microcontroller projects because its 33-instruction baseline RISC set is easy to teach and memorize. Beginners learn assembly fundamentals on the 12-bit PIC16C5X ISA before graduating to the mid-range PIC16F1xxx family with interrupts and peripherals. OTP programming via RB6/RB7 pins exercises the standard Microchip serial programming protocol, and the 18-SOIC package fits on standard DIP-to-SOIC adapter boards for breadboard use.
Recommended
Legacy Industrial Controller Card
The PIC16C54AT-04E/SO is used as a faithful replacement on legacy industrial controller cards where a previous-generation design originally specified the C5X baseline family and the surrounding analog/mixed-signal circuitry has remained unchanged. The PIC16C5X instruction set guarantees that existing firmware binaries can run without porting, and the 18-SOIC land pattern preserves the original PCB artwork. Long-term support programs (Microchip APL) often stock legacy C5X parts for industrial customers requiring decade-long product lifecycles.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54AT-04E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54A-04E/SO | PIC16C54A-20I/SO | PIC16C54-10I/P |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC (0.295" width) | 18-SOIC (same) | 18-SOIC (same) | 18-PDIP (through-hole) |
| Max Clock Frequency | 4 MHz | 4 MHz | 20 MHz | 10 MHz |
| Program Memory | 768 B OTP (512 x 12) | 768 B OTP | 768 B OTP | 768 B OTP |
| Data RAM | 25 x 8 bytes | 25 x 8 bytes | 25 x 8 bytes | 25 x 8 bytes |
| I/O Pins | 12 | 12 | 12 | 12 |
| Operating Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
| Temperature Range | -40C to +125C (Extended) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
Key Differentiators
- Lowest-cost A-silicon variant with full industrial temperature range (vs PIC16C54-10I/P)
- Same 18-SOIC footprint as faster 20 MHz C5X siblings (vs PIC16C54A-20I/SO)
- OTP memory provides read-back protection unavailable on flash PIC16F54 (vs PIC16F54-I/SO)
Design Notes
The PIC16C54AT-04E/SO draws a typical supply current of a few mA at 4 MHz and 5 V. Place a 0.1 uF ceramic bypass capacitor within 5 mm of the VDD pin (pin 14), with a 10 uF bulk tantalum or aluminum electrolytic capacitor on the same supply rail. The MCLR/VPP pin (pin 4) requires a 10 kΩ pull-up resistor to VDD for normal operation; during serial programming, the programmer drives this pin to the VPP voltage. Power-on reset is generated internally.
The 18-SOIC package (0.295" / 7.5 mm body width) follows JEDEC MS-013 with 1.27 mm pitch. Provide at least 5 mm of clearance around the package for inspection and rework, and reserve a no-route keep-out under the SOIC body for trace routing. Wide power traces on VDD/VSS reduce inductive drop during high-pin-toggle transients. A ground plane on layer 2 under the device improves supply decoupling effectiveness.
Do not assume the PIC16C54AT-04E/SO can be reprogrammed - OTP memory can be written only once. For development, use a windowed PIC16C54A or flash-based PIC16F54 drop-in on the same 18-SOIC footprint. Watchdog timer is enabled via the configuration word and, once enabled, must be periodically cleared by software (CLRWDT) or it will reset the device. Configuration word programming must occur before normal code execution begins; missing configuration bits default to safe-but-non-optimal operation.
Keep the oscillator traces (OSC1/OSC2) short and shield them with a ground guard ring to reduce EMI pickup. Place the crystal or resonator within 10 mm of the OSC1/OSC2 pins. For external clock mode, route the clock signal as a short trace over a continuous ground reference. Avoid routing high-current switching signals (relay coils, triac outputs) parallel to the oscillator traces, which can couple noise and cause unreliable clock operation.
Compliance Information
RoHS / lead-free / halogen status not stated in the verified snippet data; confirm with Microchip or distributor documentation for the specific lot. AEC-Q100 is not applicable to commercial-grade C5X baseline parts; use a Q-graded PIC for automotive safety-critical designs.
