PIC16HV540-20I/P - 8-Bit 20MHz OTP MCU w/ Shunt Regulator | Microchip
MPN: PIC16HV540-20I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.18 | $21.80 |
| 100 | $1.85 | $185.00 |
| 500 | $1.62 | $810.00 |
| 1,000 | $1.41 | $1,410.00 |
PIC16HV540-20I/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data RAM, and I/O peripherals. Within the semiconductor hierarchy, an MCU is a member of the embedded controllers / microcontrollers class, which sits under digital logic ICs and broader integrated circuits. The PIC16HV540 specifically belongs to the PIC16C mid-range family, characterized by a 12-bit instruction word, 33 single-word instructions, and a 2:1 code density advantage over competitive 8-bit MCUs.
Key features include an internal oscillator option that eliminates the need for an external crystal in cost-sensitive designs, a programmable watchdog timer with its own on-chip RC oscillator, an 8-bit real-time clock/counter with 8-bit prescaler, and a power-on reset / brown-out reset combination. Code protection is provided by security bit programming, and the device supports in-circuit serial programming (ICSP) via the RB6/RB7 pins. The shunt regulator topology internally clamps VDD, simplifying power design in battery-powered and automotive-style applications.
Typical applications include low-cost battery chargers, smart battery management, power supply monitoring and supervisory circuits, automotive subsystems, and any node that previously required an external regulator plus microcontroller combination. The wide 3.5 V to 15 V supply range and on-chip regulator make the part especially useful in 12 V lead-acid battery systems, two-cell lithium packs, and industrial control boards where the supply rail is unregulated.
When designing with the PIC16HV540-20I/P, engineers should note that the shunt regulator diverts excess current to ground as heat; at high supply voltages (12-15 V) the shunt dissipation can reach several hundred milliwatts, so PCB copper area or thermal relief matters. The OTP memory is one-time programmable - code must be verified before production burn, and field firmware updates are not possible.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, providing an independent reference for sourcing and BOM decisions.
Drop-in alternatives for PIC16HV540-20I/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 PIC16HV540-20I/P (same form factor and footprint) — differing in Package, Core Architecture, Program Memory Size, Program Memory Type, On-chip Voltage Regulator.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16HV540-20/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16HV540-04I/P
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →PIC16HV540-20I/SS
✅ Drop-In✓ In Stock
$1.45 / Unit
View Datasheet →PIC16HV540-04I/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC16HV540/JW
✅ Drop-In✓ In Stock
$6.9 / Unit
View Datasheet →PIC16HV540-20I/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C enhanced 8-bit RISC |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 768 B (512 x 12 words) |
| Data RAM | 25 B |
| Maximum Clock Speed | 20 MHz |
| Supply Voltage Range | 3.5 V to 15 V (on-chip shunt regulator) |
| I/O Pins | 12 |
| Instruction Set | 33 single-word instructions, 12-bit wide |
| Operating Temperature Range | -40 C to +85 C (industrial) |
| Package | 18-pin PDIP (DIP-18, 0.300 inch) |
| Mounting Type | Through-Hole |
| Internal Oscillator | Yes |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| In-Circuit Programming | ICSP via RB6/RB7 |
| Brown-Out Reset | Yes |
| Power-On Reset | Yes |
| Code Protection | Security bit programmable |
| Lifecycle Status | Active (in production) |
| RoHS Status | Compliant |
PIC16HV540-20I/P Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 3 | RTCC — Real-Time Clock/Counter input (T0CKI) |
| Pin 4 | MCLR — Master Clear reset input (active low) |
| 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 |
| Pin 11 | RB5 — Bidirectional I/O port B bit 5 |
| Pin 12 | RB6 — Bidirectional I/O port B bit 6 / ICSP clock |
| Pin 13 | RB7 — Bidirectional I/O port B bit 7 / ICSP data |
| Pin 14 | VDD — Positive supply (internally regulated from shunt) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock in |
| Pin 17 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 18 | RA1 — Bidirectional I/O port A bit 1 |
Typical Applications
PIC16HV540-20I/P is suitable for 6 applications: 12V Lead-Acid Battery Charger Controller, Power Supply Supervisor and Sequencer, Automotive 12V Accessory Controller, Industrial Sensor Signal Conditioner, Smart Battery Management IC Companion, Consumer Appliance User Interface.
12V Lead-Acid Battery Charger Controller
The PIC16HV540-20I/P is well suited as the control core in sealed lead-acid battery chargers because its on-chip shunt regulator accepts a 12 V to 15 V supply directly from a rectified wall adapter without any external 5 V regulator stage. Its 33-instruction RISC core executes charge-state algorithms in tens of microseconds, and the 8-bit timer with prescaler provides accurate PWM drive for a MOSFET pass element or relay cut-off. The 12 I/O pins are sufficient to drive status LEDs, sense battery voltage via the ADC-less comparator trick, and monitor temperature thermistors. Industrial temperature rating (-40 C to +85 C) tolerates garage and outdoor enclosures.
Recommended
Power Supply Supervisor and Sequencer
With its brown-out reset, power-on reset, and integrated voltage regulator, the PIC16HV540-20I/P can serve as a multi-rail supervisor in telecom and industrial power supplies. The MCU can sample multiple rails via resistor dividers into its digital inputs, assert reset to downstream ASICs via dedicated GPIO, and log fault conditions to a small EEPROM over I2C bit-banging. The 768B OTP program memory holds a complete state-machine supervisor for three to four rails with margin testing, while 25B RAM is enough for runtime flags and counters.
Recommended
Automotive 12V Accessory Controller
In 12 V automotive accessories such as lighting controllers, seat heaters, or mirror adjusters, the PIC16HV540-20I/P operates directly from the battery rail through its internal shunt regulator. The 20 MHz clock and 12-bit instruction width enable responsive PWM dimming, while the watchdog timer protects against code lockups from electrical transients. Industrial temperature rating handles under-dash thermal conditions, and the 18-pin PDIP package is friendly to through-hole assembly for low-volume automotive aftermarket parts.
Recommended
Industrial Sensor Signal Conditioner
The PIC16HV540-20I/P fits compact industrial sensor modules that need local intelligence plus direct 24 V loop-powered operation. Its on-chip shunt regulator can be configured to drop excess loop voltage, freeing the design from an external DC-DC or linear regulator. With 12 I/O pins the MCU can drive a 4-20 mA current loop, read a bridge sensor via charge-balancing techniques, and present HART or Modbus bit-banged output. Wide supply tolerance tolerates the large voltage swings common on long industrial cable runs.
Recommended
Smart Battery Management IC Companion
As a companion controller to a dedicated battery management IC, the PIC16HV540-20I/P can perform cell balancing decisions, runtime state estimation, and SMBus communication. Its 3.5 V to 15 V supply matches 2-3 cell lithium packs and 6 V / 12 V lead-acid packs without an external LDO. The 20 MHz execution speed supports Coulomb-counting calculations every few milliseconds, and the brown-out reset feature ensures clean recovery when cells deeply discharge and recover.
Recommended
Consumer Appliance User Interface
The PIC16HV540-20I/P drives keypads, 7-segment displays, and buzzer feedback in low-cost consumer appliances such as microwave ovens, washing machines, and air purifiers. Its 12 I/O pins multiplex a 4x4 key matrix and 4-digit 7-segment display with minimal external logic, and the internal oscillator saves the cost of a resonator. The 3.5 V to 15 V supply range accepts rectified mains directly, while the OTP memory locks firmware to prevent field tampering with safety-related parameters.
Recommended
Recommended Products Summary
Engineering reference data for PIC16HV540-20I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16HV540-20/P | PIC16HV540-04I/P | PIC16HV540-20I/SS | PIC16HV540-04I/SO | PIC16HV540/JW |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-pin PDIP | 18-pin PDIP - same | 18-pin PDIP - same | 18-pin SSOP - surface mount | 18-pin SOIC - surface mount | 18-pin PDIP - windowed CERDIP |
| Maximum Clock Speed | 20 MHz | 20 MHz | 4 MHz | 20 MHz | 4 MHz | 20 MHz |
| Operating Temperature Range | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) |
| Program Memory (OTP) | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) windowed EPROM |
| Data RAM | 25 B | 25 B | 25 B | 25 B | 25 B | 25 B |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| Supply Voltage Range | 3.5 V to 15 V | 3.5 V to 15 V | 3.5 V to 15 V | 3.5 V to 15 V | 3.5 V to 15 V | 3.5 V to 15 V |
Key Differentiators
- On-chip shunt voltage regulator 3.5 V to 15 V (vs PIC16F84A-I/P)
- Industrial temperature range on -20I variant (vs PIC16HV540-20/P)
- 20 MHz clock vs 4 MHz on -04 variants (vs PIC16HV540-04I/P)
Design Notes
The PIC16HV540-20I/P's on-chip shunt regulator diverts excess supply voltage as heat to maintain a constant internal VDD. At a 15 V supply with 25 mA total device current (including I/O drive), the shunt dissipates roughly (15-5) V x 0.025 A = 250 mW in the worst case. Estimated: with theta_JA near 80 C/W for PDIP-18, junction temperature rise is about 20 C above ambient - usually acceptable, but the part should not be encapsulated in a thermally sealed enclosure at maximum supply.
Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD pin and a 10 uF electrolytic or tantalum bulk capacitor near the shunt regulator pin. The shunt regulator needs adequate input capacitance to prevent input-voltage ringing during high di/dt load transients; 1 uF minimum at the supply pin is recommended per the manufacturer datasheet. Keep the MCLR pull-up resistor (typically 10 kohm) close to the MCLR pin to avoid reset glitches from injected noise.
OTP memory is one-time programmable - firmware bugs locked into production cannot be patched. Always verify code on a PIC16HV540/JW windowed part or on the PIC16HV540-20I/SO equivalent before committing to OTP burn. The ICSP pins RB6/RB7 are shared with general I/O - if your application uses these pins for external loads, isolate them during programming with jumpers or 4k7 series resistors. Brown-out reset voltage is factory-trimmed; consult the datasheet DC characteristics table for the exact BOR threshold.
The internal oscillator is RC-based and not crystal-accurate - typical tolerance is +/- 5% over temperature and voltage, which is unsuitable for UART communication without baud-rate error compensation. For UART or timing-critical applications, switch to an external crystal or ceramic resonator on OSC1/OSC2. The 20 MHz instruction cycle at 4 clocks per instruction yields a 200 ns instruction time, which constrains loop-intensive code paths.
Compliance Information
RoHS and lead-free per Microchip product environmental information. Not AEC-Q100 qualified - the -20I industrial temperature range is not automotive-grade. Halogen-free status not explicitly stated in the provided data.
