PIC16LC56A-04/P - 4MHz 8-Bit CMOS MCU, 1.5KB EPROM | Microchip
MPN: PIC16LC56A-04/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.77 | $0.77 |
| 10 | $0.7 | $7.00 |
| 100 | $0.63 | $63.00 |
| 500 | $0.57 | $285.00 |
| 1,000 | $0.5 | $500.00 |
PIC16LC56A-04/P Overview
The PIC16C5X is a baseline 8-bit microcontroller (MCU) family introduced by Microchip in the early 1990s, sitting at the entry level of the PIC micro controller taxonomy. As a Harvard-architecture device, the program and data buses are separate, allowing simultaneous fetch and access. It belongs to the broader category of microcontrollers -> embedded controllers -> microprocessors -> semiconductors. The 12-bit wide instructions are highly symmetrical, delivering 2:1 code compression over competing 8-bit MCUs in the same price class.
Key features of this device include 12 bidirectional I/O pins (port A: 4 lines; port B: 8 lines) capable of directly driving LEDs, an 8-bit real-time clock/counter with 8-bit prescaler, watchdog timer with on-chip RC oscillator for reliable operation, and Power-on Reset (POR) plus Device Reset Timer (DRT) for clean startup. The instruction cycle time of 1 microsecond at 4 MHz provides deterministic interrupt-free execution. Operating temperature range is commercial, 0C to +70C.
Architecturally, the PIC16LC56A-04/P is a low-power CMOS variant of the PIC16C56A. The LC suffix designates a wider supply voltage range (3.0 V to 6.25 V) compared with the C-version (4.5 V to 5.5 V). The EPROM-based memory enables repeated erasing via UV exposure through the ceramic windowed package option (CERDIP-18 JW), which is useful for development; the P-suffix plastic package is the production/programmed variant.
Typical applications include low-cost consumer appliances, automotive body controllers, industrial timers and counters, HVAC controls, remote transmitters, and security alarm panels. The 12-bit instruction set and 1.5KB program memory are well-matched to logic-replacement, sequencer, and basic sensor-reading tasks where an 8-bit MCU with deterministic timing is preferred over a complex Cortex-M class device.
When designing with this device, confirm that the supply rail does not dip below 3.0 V under worst-case load transients, and place a 0.1 uF decoupling capacitor within 5 mm of the VDD pin. For new designs, consider migrating to the flash-based PIC16F series for in-circuit reprogrammability, lower unit cost at moderate volumes, and wider distributor inventory.
This page synthesizes distributor pricing, parametric data, and pin-compatible same-family alternatives not found in any single manufacturer datasheet.
Drop-in alternatives for PIC16LC56A-04/P — 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 PIC16LC56A-04/P (same form factor and footprint) — differing in Program Memory Type, Operating Temperature, Package, Watchdog Timer, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C56A-04/P
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →PIC16LC56A-04I/P
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16C54A-04/P
✅ Drop-In✓ In Stock
$3.75 / Unit
View Datasheet →PIC16C55A-04/P
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →PIC16C58A-04/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC56A-04/P Maximum Ratings & Electrical Characteristics
| RAM Size | 25 bytes |
| CPU Core | PIC16C5X 8-bit RISC |
| Instruction Set Width | 12-bit |
| Maximum Clock Speed | 4 MHz |
| Instruction Cycle Time | 1 us at 4 MHz |
| Number of Instructions | 33 |
| Supply Voltage (VDD) | 3.0 V to 6.25 V |
| I/O Pins | 12 (4 RA + 8 RB) |
| Timers | 1 x 8-bit RTCC with 8-bit prescaler |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Program Memory Type | EPROM (UV-erasable windowed CERDIP option) |
| Package | 18-pin PDIP (P) |
| Mounting Type | Through-Hole |
| Operating Temperature | 0C to +70C (Commercial) |
| Power-on Reset | Yes |
| Interrupt Controller | None (baseline PIC16C5X family has no interrupts) |
PIC16LC56A-04/P Pin Configuration
| Pin 1 | /MCLR — Master Clear (active-low reset input) |
| Pin 2 | RA0 — Port A bit 0 (digital I/O) |
| Pin 3 | RA1 — Port A bit 1 (digital I/O) |
| Pin 4 | RA2 — Port A bit 2 (digital I/O) |
| Pin 5 | RA3 — Port A bit 3 (digital I/O) |
| Pin 6 | RB0/INT — Port B bit 0 (digital I/O) |
| Pin 7 | RB1 — Port B bit 1 (digital I/O) |
| Pin 8 | RB2 — Port B bit 2 (digital I/O) |
| Pin 9 | RB3 — Port B bit 3 (digital I/O) |
| Pin 10 | RB4 — Port B bit 4 (digital I/O) |
| Pin 11 | RB5 — Port B bit 5 (digital I/O) |
| Pin 12 | RB6 — Port B bit 6 (digital I/O) |
| Pin 13 | RB7 — Port B bit 7 (digital I/O) |
| Pin 14 | VSS — Ground reference |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock-out |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock in |
| Pin 17 | VDD — Positive supply |
| Pin 18 | VDD — Positive supply (tied to pin 17) |
Typical Applications
PIC16LC56A-04/P is suitable for 6 applications: Low-Cost Consumer Appliance Controller, Automotive Body Control Module (Legacy), Industrial Timer and Counter, HVAC Control Board, Remote Control / RF Transmitter, Security Alarm Panel.
Low-Cost Consumer Appliance Controller
The PIC16LC56A-04/P fits appliance control boards because its 1.5 KB EPROM and 12 I/O are sufficient for sequencing relays, reading tactile buttons, and driving 7-segment LED displays. At 4 MHz with 1 us instruction cycle, the MCU can refresh displays at 100 Hz while polling inputs. The 3.0-6.25 V supply range lets it run directly from rectified mains or a 5 V regulator. The baseline architecture has no interrupts, so timing-critical loops must be polled, simplifying code review for safety-critical white goods.
Recommended
Automotive Body Control Module (Legacy)
Automotive body controllers for seat, mirror, or window functions historically used baseline PIC16C5X devices because of their deterministic interrupt-free architecture and wide temperature variants. The PIC16LC56A-04/P provides 12 I/O sufficient for motor direction relays and limit-switch inputs. The -04 grade runs at 4 MHz which is adequate for slow body-control loops. For new automotive designs, prefer AEC-Q100 qualified PIC16F series; the PIC16LC56A is suitable only for maintaining legacy installed base.
Recommended
Industrial Timer and Counter
The PIC16LC56A-04/P's on-chip 8-bit RTCC with 8-bit prescaler makes it well suited for industrial timing applications such as conveyor sequencers, machine-cycle counters, and process timers. The 12 I/O can directly drive 24 V optically isolated inputs and outputs via external optocouplers. The wide 3.0-6.25 V supply range accepts regulated 24 V industrial rails down-converted to 5 V. Industrial variants (-04I/P) extend the operating temperature to -40C to +85C for factory environments.
Recommended
HVAC Control Board
HVAC thermostats and damper controllers use baseline PIC16C5X MCUs because the deterministic instruction execution simplifies thermal-loop timing analysis. The PIC16LC56A-04/P provides 12 I/O sufficient for fan relay control, temperature sensor sampling via external ADC, and triac firing. The 3.0 V minimum supply lets the MCU operate from a single-cell lithium backup battery during power-outage thermostat operation. Watchdog timer with on-chip RC oscillator prevents code lockup from EMI on long HVAC wiring.
Recommended
Remote Control / RF Transmitter
Simple RF remote controls (garage-door openers, key fobs, security transmitters) are a classic application for PIC16LC56A-04/P because the device only needs to scan a button matrix and generate a fixed-code or rolling-code transmission. The 12 I/O can read up to 12 buttons; 1.5 KB EPROM stores the encoding table. The 3.0 V minimum supports coin-cell or two-AA battery operation. Baseline architecture has no interrupts so transmission timing is jitter-free, simplifying FCC / ETSI emission compliance.
Recommended
Security Alarm Panel
The PIC16LC56A-04/P's watchdog timer and Power-on Reset make it a viable controller for wired security alarm panels that monitor door/window sensors and drive a siren. Twelve I/O can read up to 12 zones (with external diode matrixing, more). The deterministic 4 MHz execution ensures consistent loop time for tamper detection. The wide supply range accepts backup-battery operation. Baseline architecture has no interrupts so all event handling is polled, simplifying safety certification of the alarm logic.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC56A-04/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C56A-04/P | PIC16LC56A-04I/P | PIC16C54A-04/P | PIC16C58A-04/P |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-pin PDIP (P) | 18-pin PDIP - same | 18-pin PDIP - same | 18-pin PDIP - same | 18-pin PDIP - same |
| Program Memory | 1.5 KB EPROM | 1.5 KB EPROM | 1.5 KB EPROM | 0.75 KB EPROM (-50%) | 2 KB EPROM (+33%) |
| RAM Size | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 73 bytes (+192%) |
| Max Clock Frequency | 4 MHz | 10 MHz (+150%) | 4 MHz | 4 MHz | 4 MHz |
| Supply Voltage | 3.0 V to 6.25 V | 4.5 V to 5.5 V (narrower) | 3.0 V to 6.25 V | 3.0 V to 6.25 V (LC) or 4.5-5.5 V (C) | 3.0 V to 6.25 V (LC) or 4.5-5.5 V (C) |
| I/O Pins | 12 | 12 | 12 | 12 | 12 |
| Operating Temperature | 0C to +70C (Commercial) | 0C to +70C | -40C to +85C (Industrial) | 0C to +70C | 0C to +70C |
Key Differentiators
- Wider supply voltage range than the C-variant (vs PIC16C56A-04/P)
- Industrial temperature option exists in the same package (vs PIC16C56A-04/P (commercial only))
- Baseline architecture with no interrupts for deterministic code review (vs PIC16F84A flash MCU)
Design Notes
Estimated: at 4 MHz and 5 V supply the PIC16LC56A-04/P draws approximately 2 mA active and 1 uA standby per the PIC16C5X datasheet. Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 17, tied to pin 18) and a 10 uF bulk capacitor near the regulator. For battery-powered designs, switch the supply off via a P-MOSFET controlled by the watchdog timer to achieve sub-microamp sleep current.
The baseline PIC16C5X family has NO interrupt controller. All event handling must be polled in the main loop. Do not write ISR code - it will silently never execute. Also note that /MCLR (pin 1) must be tied to VDD through a 10 kohm resistor; leaving it floating causes intermittent resets. The CONFIG word must be programmed to select the oscillator mode (RC, XT, HS, LP) - unconfigured parts will not start.
Route the oscillator traces (pins 15 OSC2 and 16 OSC1) as short as possible, with the crystal or resonator within 5 mm of the package. Keep oscillator traces away from I/O switching lines to avoid coupling. Place a ground guard ring around the crystal and a 100 nF capacitor on the /MCLR pin. For RC oscillator mode, place the timing resistor and capacitor close to OSC1. PDIP package allows easy breadboard prototyping.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified; for automotive applications requiring AEC-Q100, use PIC16F1827 or similar flash MCU. Lead-free matte-tin finish on PDIP pins.
