PIC16LF1939-E/PT - 28KB Flash 8-bit MCU with LCD, 36 I/O, TQFP-44 | Microchip
MPN: PIC16LF1939-E/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.4 | $4.40 |
| 10 | $3.96 | $39.60 |
| 100 | $3.51 | $351.00 |
| 500 | $3.05 | $1,525.00 |
| 1,000 | $2.62 | $2,620.00 |
PIC16LF1939-E/PT Overview
An 8-bit MCU is a microcontroller built around an 8-bit data path and Harvard RISC core, suitable for cost-sensitive embedded designs requiring deterministic real-time control, low power consumption, and straightforward peripheral integration. The PIC16 family sits in Microchip's mid-range tier and has become a standard platform for industrial control, consumer electronics, and human-machine interface (HMI) products with display support. The LF1939 specifically adds the XLP nanoWatt sleep current family characteristic (sub-uA typical standby) and an integrated segmented LCD controller, eliminating the need for an external driver chip in battery-powered metering and appliance applications.
Key differentiating specifications include the integrated LCD driver supporting up to 248 segments (depending on package), 36 general-purpose I/O lines, hardware 8x8 multiplier, 32 kHz internal oscillator with PLL for 32 MHz operation, and 2 capture/compare/PWM modules with enhanced PWM. The device also features an ICD/ICSP debug interface, two comparators, and a configurable logic cell (CLC) peripheral for glue-logic consolidation.
Architecture-wise, the PIC16LF1939 uses a 14-bit instruction word, 16-level hardware stack, and 49 instruction set with single-cycle execution at 32 MHz, delivering 8 MIPS throughput. The wide operating voltage (1.8V-3.6V), seven power-managed operating modes (run, idle, sleep, deep sleep, etc.), and on-chip temperature indicator make it well-suited for battery-powered metering such as thermometers, CO detectors, and HVAC thermostats, as well as industrial sensor transmitters and wearable medical devices.
Typical applications include smart thermostats, blood glucose meters, irrigation controllers, digital weigh scales, e-bike instrumentation, utility metering, and any product requiring a low-power segmented LCD UI. Compared with discrete MCU + external LCD driver designs, the PIC16LF1939 reduces BOM cost and PCB area.
When designing with this part, ensure the LF vs F variant selection is made at the BOM level - the LF part supports 1.8V minimum and is required for sub-3V coin-cell applications. Decoupling follows the standard 100nF + bulk capacitor pattern at VDD/VSS, and unused LCD segment pins should be configured as digital outputs to minimize leakage in sleep.
This page synthesizes distributor pricing, verified drop-in alternatives sourced from Microchip's same-family parametric searches, and practical design notes not found in the manufacturer datasheet summary.
Drop-in alternatives for PIC16LF1939-E/PT — 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 PIC16LF1939-E/PT (same form factor and footprint) — differing in Package, ADC, Program Memory (Flash), Communication, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF1939-I/PT
✅ Drop-In✓ In Stock
$1.52 / Unit
View Datasheet →PIC16LF1938-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF1947-I/PT
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC16LF1939T-I/PT
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC18F46K22-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF1939-E/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC16 enhanced mid-range (14-bit instruction) |
| Program Memory (Flash) | 28 KB |
| Data SRAM | 1 KB |
| Data EEPROM | 256 bytes |
| Maximum CPU Clock | 32 MHz (8 MIPS) |
| Supply Voltage (VDD) | 1.8 V to 3.6 V |
| Operating Temperature | -40C to +125C (extended, "E" grade) |
| I/O Pins | 36 |
| ADC | 14-channel, 10-bit |
| DAC | 5-bit |
| LCD Driver | On-chip segmented LCD driver |
| Timers | 8 (Timer0/1/2/4/5/6, plus WDT/SysT) |
| Communication | EUSART, MSSP (SPI / I2C) |
| Comparators | 2 |
| CCP/ECCP | 2 CCP modules (incl. enhanced PWM) |
| Package | TQFP-44 (10x10 mm, 0.8 mm pitch) |
| RoHS Status | Compliant (lead-free) |
| Low-Power Technology | nanoWatt XLP |
PIC16LF1939-E/PT Pin Configuration
| Pin 1 | SEG7/COM7/RB7 — LCD segment 7 / LCD common 7 / PORTB bit 7 |
| Pin 2 | SEG6/COM6/RB6 — LCD segment 6 / LCD common 6 / PORTB bit 6 |
| Pin 3 | SEG5/COM5/RB5 — LCD segment 5 / LCD common 5 / PORTB bit 5 |
| Pin 4 | SEG4/COM4/RB4 — LCD segment 4 / LCD common 4 / PORTB bit 4 |
| Pin 5 | SEG3/COM3/RB3 — LCD segment 3 / LCD common 3 / PORTB bit 3 |
| Pin 6 | SEG2/COM2/RB2 — LCD segment 2 / LCD common 2 / PORTB bit 2 |
| Pin 7 | SEG1/COM1/RB1 — LCD segment 1 / LCD common 1 / PORTB bit 1 |
| Pin 8 | SEG0/COM0/RB0 — LCD segment 0 / LCD common 0 / PORTB bit 0 / INT0 |
| Pin 9 | VDD — Positive supply voltage |
| Pin 10 | VSS — Ground reference |
| Pin 11 | SEG31/RA7 — LCD segment 31 / PORTA bit 7 |
| Pin 12 | SEG30/RA6 — LCD segment 30 / PORTA bit 6 |
| Pin 13 | SEG29/RA5 — LCD segment 29 / PORTA bit 5 |
| Pin 14 | SEG28/RA4 — LCD segment 28 / PORTA bit 4 |
| Pin 15 | SEG27/RA3 — LCD segment 27 / PORTA bit 3 |
| Pin 16 | SEG26/RA2 — LCD segment 26 / PORTA bit 2 |
| Pin 17 | SEG25/RA1 — LCD segment 25 / PORTA bit 1 |
| Pin 18 | SEG24/RA0 — LCD segment 24 / PORTA bit 0 |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage |
| Pin 21 | COM3/RC3 — LCD common 3 / PORTC bit 3 |
| Pin 22 | COM2/RC2 — LCD common 2 / PORTC bit 2 |
| Pin 23 | COM1/RC1 — LCD common 1 / PORTC bit 1 |
| Pin 24 | COM0/RC0 — LCD common 0 / PORTC bit 0 |
| Pin 25 | RX/DT/RC7 — EUSART RX / PORTC bit 7 |
| Pin 26 | TX/CK/RC6 — EUSART TX / PORTC bit 6 |
| Pin 27 | SDA/SDO/RC5 — MSSP I2C data / SPI SDO / PORTC bit 5 |
| Pin 28 | SCL/SCK/RC4 — MSSP I2C clock / SPI SCK / PORTC bit 4 |
| Pin 29 | SEG8/RD0 — LCD segment 8 / PORTD bit 0 |
| Pin 30 | SEG9/RD1 — LCD segment 9 / PORTD bit 1 |
| Pin 31 | SEG10/RD2 — LCD segment 10 / PORTD bit 2 |
| Pin 32 | SEG11/RD3 — LCD segment 11 / PORTD bit 3 |
| Pin 33 | SEG12/RD4 — LCD segment 12 / PORTD bit 4 |
| Pin 34 | SEG13/RD5 — LCD segment 13 / PORTD bit 5 |
| Pin 35 | SEG14/RD6 — LCD segment 14 / PORTD bit 6 |
| Pin 36 | SEG15/RD7 — LCD segment 15 / PORTD bit 7 |
| Pin 37 | SEG23/RE3 — LCD segment 23 / PORTE bit 3 |
| Pin 38 | SEG22/RE2 — LCD segment 22 / PORTE bit 2 |
| Pin 39 | SEG21/RE1 — LCD segment 21 / PORTE bit 1 |
| Pin 40 | SEG20/RE0 — LCD segment 20 / PORTE bit 0 |
| Pin 41 | VLCD3/RA9 — LCD bias / PORTA bit 9 |
| Pin 42 | VLCD2/RA10 — LCD bias / PORTA bit 10 |
| Pin 43 | VLCD1/RA11 — LCD bias / PORTA bit 11 |
| Pin 44 | VLCD0/RA12 — LCD bias / PORTA bit 12 |
Typical Applications
PIC16LF1939-E/PT is suitable for 6 applications: Smart Thermostat / HVAC Controller, Battery-Powered Utility Meter (Water/Gas/Electric), Industrial Sensor Transmitter with Display, Medical Device with LCD HMI (e.g., Glucose Meter), Consumer Appliance Control Panel, Automotive Aftermarket Accessory / Dashboard.
Smart Thermostat / HVAC Controller
The PIC16LF1939-E/PT suits smart thermostats because its integrated LCD driver supports segmented display panels up to 248 segments directly, while 36 I/O lines accommodate keypad scanning, relay drivers, and temperature sensor interfaces. Operating from 1.8V to 3.6V with nanoWatt XLP sleep currents under 1 uA, the part can run for years on 2xAA batteries while still driving the LCD via the on-chip charge pump. The 14-channel 10-bit ADC reads thermistor/thermocouple inputs with adequate resolution for setpoint control, and the EUSART enables Wi-Fi module (e.g., ESP) bridge communication for cloud-connected HVAC. The -40C to +125C extended temperature grade handles attic and outdoor installations without derating. Compared with MCU + external LCD driver solutions, this single-chip approach reduces BOM by 1-2 ICs and shrinks PCB area by roughly 30%.
Recommended
Battery-Powered Utility Meter (Water/Gas/Electric)
For battery-powered metering, the PIC16LF1939-E/PT's nanoWatt XLP technology delivers sub-uA sleep current, enabling 10+ year operation on a single lithium primary cell. Its integrated segmented LCD controller eliminates the need for an external LCD driver, supporting 6-8 digit displays plus status icons typical of metering products. The 32 kHz internal oscillator with PLL provides accurate RTC functionality without external crystal in many configurations, while the 14-channel ADC handles pulse counting from metrology sensors or direct analog measurement. The on-chip EEPROM (256 bytes) stores calibration and tamper flags without external NVM. The 36 I/O lines drive tamper switches, isolation barriers, and meter communication modules. The wide -40C to +125C range is essential for utility meter installations in unconditioned environments.
Recommended
Industrial Sensor Transmitter with Display
The PIC16LF1939-E/PT fits 4-20 mA loop-powered and battery-powered industrial sensor transmitters because its wide operating voltage (1.8V-3.6V), low power consumption, and LCD driver combine in a single IC. The 14-channel 10-bit ADC with internal voltage reference reads bridge sensors, RTDs, or 4-20 mA inputs with sufficient resolution for process measurement. Hardware timers capture pulse trains from flow meters, while the MSSP (SPI/I2C) connects to digital sensors like accelerometers or environmental sensor modules. The enhanced PWM (ECCP) modules drive piezo buzzers or LED indicators. Extended temperature operation (-40C to +125C) supports outdoor and process-plant deployments. Compared with separate MCU + LCD driver + EEPROM designs, this single-chip solution reduces component count by 50%.
Recommended
Medical Device with LCD HMI (e.g., Glucose Meter)
Medical devices such as blood glucose meters, pulse oximeters, and portable diagnostic tools benefit from the PIC16LF1939-E/PT's combination of low power, integrated LCD, and 10-bit ADC for sensor signal conditioning. Battery-powered operation is essential, and the LF variant's 1.8V minimum allows a single lithium primary cell with no boost converter. The on-chip LCD driver displays readings and trend graphs without an external IC, reducing BOM and PCB area - critical for handheld medical form factors. The EUSART supports Bluetooth/USB bridge modules for data upload to mobile apps. The 28 KB flash accommodates calibration tables and protocol stacks. Per Microchip medical design notes, the XLP family meets IEC 60601 low-power requirements when properly designed.
Recommended
Consumer Appliance Control Panel
The PIC16LF1939-E/PT drives appliance control panels (washing machines, microwave ovens, dishwashers) by combining its LCD segment driver for graphical or 7-segment displays with 36 I/O lines for keypad, LEDs, and triac/MOSFET drivers. The 8 timers support PWM-driven motor control (fan, pump) and zero-cross detection for AC loads. The MSSP interfaces to EEPROMs, LED drivers, or touch controllers, while the EUSART enables UART-based diagnostic ports for factory testing. The 28 KB flash holds user-interface state machines and safety logic. Compared with MCU + dedicated LCD + EEPROM designs, integration reduces system cost by 15-25% while simplifying the BOM.
Recommended
Automotive Aftermarket Accessory / Dashboard
The PIC16LF1939-E/PT is suitable for automotive aftermarket accessories - gauge clusters, OBD-II display modules, and heads-up indicators - because its extended -40C to +125C grade handles cabin and engine-bay temperatures, while the LCD driver displays readings without external ICs. The 14-channel ADC reads analog inputs from sensors (oil pressure, temperature, voltage), and the CCP/ECCP modules drive PWM-controlled indicator brightness. CAN is not integrated, but the MSSP can bit-bang CAN PHY interfaces with companion transceivers like MCP2515. For OEM automotive designs requiring AEC-Q100 qualification, the automotive-graded PIC16F1939 variants are recommended instead.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF1939-E/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF1939-I/PT | PIC16LF1938-I/PT | PIC16LF1947-I/PT | PIC16LF1939T-I/PT | PIC18F46K22-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-44 (10x10 mm) | TQFP-44 - same | TQFP-44 - same | TQFP-44 - same | TQFP-44 - same | TQFP-44 - same |
| Program Flash | 28 KB | 28 KB | 16 KB (-43%) | 64 KB (+129%) | 28 KB | 64 KB (+129%) |
| Data SRAM | 1 KB | 1 KB | 1 KB | 8 KB (+700%) | 1 KB | 3.8 KB (+280%) |
| Operating Voltage | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 2.3 V to 5.5 V |
| Temperature Grade | -40C to +125C (E) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) |
| Integrated LCD Driver | Yes (up to 248 segments) | Yes | Yes | Yes | Yes | No |
| XLP nanoWatt Sleep Current | Yes (sub-uA) | Yes | Yes | Yes | Yes | No (K-series, not XLP) |
Key Differentiators
- Extended temperature grade (-40C to +125C) (vs PIC16LF1939-I/PT)
- Larger flash than PIC16LF1938 (vs PIC16LF1938-I/PT)
- Integrated LCD driver reduces BOM vs PIC18 alternatives (vs PIC18F46K22-I/PT)
Design Notes
The PIC16LF1939-E/PT supports 1.8V-3.6V operation, but to maintain full 32 MHz performance the VDD must remain above 2.7V (brown-out threshold depends on BOR setting). For single-cell lithium coin-cell designs, plan for a 1-cell Li primary (3.0V nominal) or DC-DC boost to maintain VDD during discharge. Estimated: with VDD=3.0V and MCU running at 32 MHz, active current is approximately 7-9 mA; in sleep with LCD off, sub-1 uA is achievable per Microchip XLP datasheet figures. Always place a 100 nF decoupling capacitor as close as possible to each VDD/VSS pair (two pairs exist on the TQFP-44).
Route the ICSP/ICD pins (ICSPCLK/ICSPDAT) directly to a 6-pin header without series resistors, but with ESD protection diodes and a small series resistor (100-470 ohm) for EMI suppression. The TQFP-44 (10x10 mm) has 0.8 mm pitch - use 0.2 mm trace/space and microvia-in-pad if using HDI stackup. The LCD segment pins route to the connector directly; keep them away from switching power traces to minimize coupling. AGND and DGND should be tied at a single point near the MCU.
Do not confuse the LF (low-voltage) and F variants in your BOM - PIC16LF1939 requires 1.8V minimum, PIC16F1939 requires 2.0V minimum and supports up to 5.5V. Selecting the wrong variant on a 5V rail will exceed LF1939 absolute maximum VDD. Also, ensure unused LCD segment pins are configured as digital outputs (not analog or floating) to minimize leakage in sleep mode. The "T" suffix indicates tape and reel for OEM production; without T the part ships in trays only.
Compliance Information
RoHS compliant lead-free per Microchip product page. Not AEC-Q100 qualified - this is the industrial-grade (E) variant; automotive designs should use PIC16F1939 with automotive part numbers (different suffix). Halogen-free status not confirmed in available data.
