PIC16LF1938-I/SO - 8-Bit XLP MCU 32MHz 28KB Flash | Microchip
MPN: PIC16LF1938-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.17 | $3.17 |
| 10 | $2.85 | $28.50 |
| 100 | $2.42 | $242.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.74 | $1,740.00 |
PIC16LF1938-I/SO Overview
An 8-bit microcontroller (MCU) is a small, self-contained computer-on-a-chip combining a CPU, non-volatile program memory (Flash), volatile data memory (RAM), non-volatile user data memory (EEPROM), and a rich set of peripherals (timers, ADC, comparators, communication interfaces, I/O). It sits in the embedded hierarchy as follows: MCU -> microcontroller -> microprocessor -> semiconductor. The 'F' in PIC16F denotes Flash program memory, while the 'L' suffix denotes a low-voltage variant optimized for operation down to 1.8 V, making it a member of the broader PIC16 family and the larger 8-bit PIC ecosystem.
Key features include a 10-bit ADC, multiple timers, an integrated LCD driver supporting up to 96 segments, nanoWatt XLP sleep current down to the manufacturer-claimed extreme-low range, 1.8 V to 3.6 V core voltage operation (5.5 V on I/O depending on configuration), and on-chip peripherals suitable for human-machine interface (HMI) and metering products. The 28-SOIC package is the most popular through-hole-style surface-mount option for hand-solderable prototyping in this family.
Architecturally, the PIC16LF1938 uses Microchip's enhanced mid-range 8-bit core with a hardware multiplier, 14-bit instruction word (16K x 14 Flash = 28 KB), and a deterministic interrupt architecture. The integrated LCD driver, multiple PWM modules, Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART), SPI, I2C, and analog comparators reduce external component count, enabling compact BOMs.
Typical applications include battery-powered metering (electricity, water, gas), thermostat and HVAC controls, consumer white goods with LCD readouts, medical point-of-care devices, IoT sensor nodes, and industrial HMI panels. The combination of LCD driver, EEPROM, and nanoWatt XLP power modes makes it particularly attractive for line-powered-with-battery-backup meters and low-power hand-held instruments.
When designing with this part, ensure the supply decoupling network uses a 100 nF ceramic close to VDD with a bulk 10 µF; place the 32.768 kHz crystal or internal oscillator reference near the OSC pins and guard the analog AV/DD rail. Reserve one I/O for In-Circuit Serial Programming™ (ICSP™) via PGC/PGD to allow firmware updates after board assembly.
This page synthesizes distributor pricing snapshots, drop-in alternative listings, and practical design notes - particularly around the LCD bias network and nanoWatt XLP sleep modes - that go beyond the manufacturer datasheet narrative to accelerate your BOM and firmware work.
Drop-in alternatives for PIC16LF1938-I/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 PIC16LF1938-I/SO (same form factor and footprint) — differing in Package, Timers, ADC, Operating Temperature, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF1938T-I/SO
✅ Drop-In✓ In Stock
$2.62 / Unit
View Datasheet →PIC16F1938-I/SO
✅ Drop-In✓ In Stock
$3.08 / Unit
View Datasheet →PIC16LF1937-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF1936-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF1938-I/SS
✅ Drop-In✓ In Stock
$2.21 / Unit
View Datasheet →PIC16LF1938-I/SO Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Size | 8-Bit |
| Program Memory Size | 28 KB (16K x 14) FLASH |
| RAM Size | 1 KB |
| EEPROM Size | 256 B |
| Maximum Clock Speed | 32 MHz |
| Operating Voltage Range (Core VDD) | 1.8 V to 3.6 V |
| I/O Voltage Range | 1.8 V to 5.5 V |
| Number of I/O Pins | 25 |
| ADC | 10-bit |
| Integrated LCD Driver | Yes |
| Timers | 5 (multiple 8/16-bit) |
| Communication Interfaces | EUSART, I2C, SPI |
| Package | 28-SOIC (0.295 in / 7.50 mm width) |
| Operating Temperature | -40C to +85C (Industrial, 'I' grade) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC16LF1938-I/SO Pin Configuration
| Pin 1 | RA3/AN3/C1IN+/VREF+ — GPIO RA3 / Analog input / Comparator input / Voltage reference plus |
| Pin 2 | RA4/T0CKI/C1OUT — GPIO RA4 / Timer0 clock input / Comparator 1 output |
| Pin 3 | RA5/AN4/C2IN-/SS/HLVDIN — GPIO RA5 / Analog input / Comparator input / SPI SS / HLVD input |
| Pin 4 | RA6/OSC2/CLKOUT — GPIO RA6 / Oscillator output / Clock output |
| Pin 5 | RA7/OSC1/CLKIN — GPIO RA7 / Oscillator input / External clock input |
| Pin 6 | RC0/T1OSO/T1CKI — GPIO RC0 / Timer1 oscillator output / Timer1 clock input |
| Pin 7 | RC1/T1OSI/CCP2 — GPIO RC1 / Timer1 oscillator input / CCP2 |
| Pin 8 | RC2/AN6/CCP1 — GPIO RC2 / Analog input / CCP1 |
| Pin 9 | RC3/AN7/SEG0 — GPIO RC3 / Analog input / LCD segment 0 |
| Pin 10 | RC4/C2OUT/SEG1 — GPIO RC4 / Comparator 2 output / LCD segment 1 |
| Pin 11 | RC5/CCP3/SEG2 — GPIO RC5 / CCP3 / LCD segment 2 |
| Pin 12 | RC6/TX/CK/SEG3 — GPIO RC6 / EUSART TX / EUSART CK / LCD segment 3 |
| Pin 13 | RC7/RX/DT/SEG4 — GPIO RC7 / EUSART RX / EUSART DT / LCD segment 4 |
| Pin 14 | RD0/COM3/PSP0 — GPIO RD0 / LCD COM3 / Parallel Slave Port data |
| Pin 15 | RD1/COM2/PSP1 — GPIO RD1 / LCD COM2 / Parallel Slave Port data |
| Pin 16 | RD2/CCP4/COM1/PSP2 — GPIO RD2 / CCP4 / LCD COM1 / Parallel Slave Port data |
| Pin 17 | RD3/CCP5/COM0/PSP3 — GPIO RD3 / CCP5 / LCD COM0 / Parallel Slave Port data |
| Pin 18 | RD4/SEG5/PSP4 — GPIO RD4 / LCD segment 5 / Parallel Slave Port data |
| Pin 19 | VSS — Ground |
| Pin 20 | VDD — Positive supply voltage (1.8 V to 3.6 V) |
| Pin 21 | RB0/AN12/INT/SEG6 — GPIO RB0 / Analog input / External interrupt / LCD segment 6 |
| Pin 22 | RB1/AN10/C12IN3-/P1C — GPIO RB1 / Analog input / Comparator input / PWM output |
| Pin 23 | RB2/AN8/CPS/P1B — GPIO RB2 / Analog input / Capacitive touch sense / PWM output |
| Pin 24 | RB3/AN9/CPG/P1A — GPIO RB3 / Analog input / Capacitive sense / PWM output |
| Pin 25 | RB4/AN11/CPSB/KBI0 — GPIO RB4 / Analog input / Capacitive sense / KBI interrupt |
| Pin 26 | RB5/AN13/CPSA/KBI1 — GPIO RB5 / Analog input / Capacitive sense / KBI interrupt |
| Pin 27 | RB6/ICSPCLK/KBI2 — GPIO RB6 / ICSP clock / KBI interrupt |
| Pin 28 | RB7/ICSPDAT/KBI3 — GPIO RB7 / ICSP data / KBI interrupt |
Typical Applications
PIC16LF1938-I/SO is suitable for 7 applications: Battery-Powered Electric Meter with LCD Readout, Thermostat and HVAC Controller, Consumer White Goods (Washing Machine, Rice Cooker, Microwave), Portable Medical Point-of-Care Device, IoT Sensor Node with Local LCD Display, Industrial HMI Panel (Operator Interface), Home Appliance Control Board (Coffee Machine, Oven, Refrigerator).
Battery-Powered Electric Meter with LCD Readout
The PIC16LF1938-I/SO is ideal for battery-powered electricity, water, and gas meters because its integrated LCD driver supports up to 96 segments with internal charge pump and bias resistor ladder, eliminating the need for an external LCD controller. The nanoWatt XLP technology delivers sleep currents in the sub-microamp range with RTC running, extending coin-cell or Li-ion battery life to 10+ years. The 28 KB Flash provides ample space for billing algorithms, tamper detection logic, and TOU tariff tables. In a typical design the MCU is placed between the battery and a CT/front-end signal conditioning circuit, with the LCD directly multiplexed onto the meter's glass, achieving a single-IC BOM that minimizes quiescent current.
Recommended
Thermostat and HVAC Controller
The PIC16LF1938-I/SO fits thermostat and HVAC control designs that need an LCD screen, multiple keypad inputs, and relay/triac outputs without a complex RTOS. Its 32 MHz core gives enough MIPS for proportional control loops, while the 10-bit ADC handles temperature sensor (NTC or analog IC) reads with adequate resolution for 0.5C control steps. The 1 KB RAM supports small scheduling tables for setback programming. The 28-SOIC package is hand-solderable for low-volume HVAC product lines. In circuit, it sits between the line-power-derived 3.3 V rail and the relay/triac driver stage, with the LCD indicating setpoint and ambient temperature in a low-power UI loop.
Recommended
Consumer White Goods (Washing Machine, Rice Cooker, Microwave)
The PIC16LF1938-I/SO is well-suited to consumer white goods that combine an LCD/LED front panel, sensor inputs (water level, weight, door switch, temperature), and motor/valve actuation. The 25 I/O pins easily drive multiplexed 7-segment displays or character LCDs while also scanning keypads and driving triacs. The 256-byte EEPROM provides non-volatile storage for user settings, wash cycles, and fault logs across power cycles. Its industrial -40C to +85C temperature range handles the harsh environment behind a washing machine panel. Placed on the control board between the 3.3 V LDO and the relay/triac bank, the MCU orchestrates timing, sensing, and user interface in a single chip, reducing total BOM versus multi-chip solutions.
Recommended
Portable Medical Point-of-Care Device
The PIC16LF1938-I/SO fits portable medical devices such as glucose meters, pulse oximeters, and INR testers where low power consumption, deterministic real-time response, and a small LCD are required. The nanoWatt XLP sleep currents allow weeks of standby on coin cells, while the 32 MHz CPU burst supports fast ADC sampling for biosensor readouts. The 256-byte EEPROM stores calibration constants and patient log entries, and the EUSART/SPI/I2C peripherals connect to wireless modules or display drivers. According to the Microchip datasheet, the LCD driver's internal charge pump maintains display contrast even when battery voltage drops to 2.0 V, ensuring reliable readouts throughout battery life.
Recommended
IoT Sensor Node with Local LCD Display
The PIC16LF1938-I/SO serves as the local controller in IoT sensor nodes where a small LCD provides local status, calibration, or last-readout indication without a smartphone app. The integrated LCD, EUSART for connecting to an ESP8266/LoRa sub-module, and 10-bit ADC for analog sensor reading make it a strong fit. Its sleep current with LCD running on internal charge pump is well under 5 uA, supporting multi-year battery deployment. In the typical circuit the PIC16LF1938 sits between the battery, the LCD glass (multiplexed via on-chip bias network), and the radio module's UART, providing local intelligence and display while the radio handles backhaul.
Recommended
Industrial HMI Panel (Operator Interface)
The PIC16LF1938-I/SO can drive industrial operator-interface panels that need a 4 to 8-line character LCD, multiple pushbuttons, and Modbus/EUSART communication to a host controller. Its 28 KB Flash accommodates character tables, menu state machines, and protocol stacks; 1 KB RAM holds command buffers; and 256 bytes EEPROM stores non-volatile settings such as node address and calibration. The 10-bit ADC reads potentiometers or analog setpoints, and PWM outputs can drive LED backlights or status indicators. The 28-SOIC industrial-grade (-40C to +85C) part fits in panels exposed to factory-floor temperature swings, placed near the LCD connector with ESD protection on the keypad lines.
Recommended
Home Appliance Control Board (Coffee Machine, Oven, Refrigerator)
The PIC16LF1938-I/SO is well-suited to home appliance control boards that combine an LCD or 7-segment display, capacitive or mechanical key scanning, and triac/relay outputs for heating elements, pumps, and valves. The 256 bytes of EEPROM store user presets and error logs that must survive power cycles, and the 32 MHz core delivers responsive UI updates. According to the Microchip datasheet, the integrated LCD controller with internal bias resistor ladder eliminates the external resistor network normally required for character LCDs, simplifying the BOM. The MCU is placed between the 3.3 V LDO and the display/relay drivers, with the I2C bus extending to optional sensors like temperature or humidity ICs.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF1938-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF1938T-I/SO | PIC16F1938-I/SO | PIC16LF1937-I/SO | PIC16LF1936-I/SO |
|---|---|---|---|---|---|
| Package | 28-SOIC | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 28 KB | 28 KB | 28 KB | 14 KB | 14 KB |
| RAM | 1 KB | 1 KB | 1 KB | 1 KB | 512 B |
| EEPROM | 256 B | 256 B | 256 B | 256 B | 256 B |
| Operating Voltage Range | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 5.5 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V |
| Max Clock Speed | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz |
| Integrated LCD Driver | Yes | Yes | Yes | Yes | Yes |
| Temperature Grade | Industrial -40C to +85C | Industrial -40C to +85C | Industrial -40C to +85C | Industrial -40C to +85C | Industrial -40C to +85C |
Key Differentiators
- Highest-density Flash in 28-pin PIC16LF193x family (vs PIC16LF1937-I/SO)
- Low-voltage variant optimized for sub-3.6 V battery designs (vs PIC16F1938-I/SO)
- Integrated LCD driver eliminates external LCD controller (vs PIC16LF1906-I/SP)
Design Notes
Place a 100 nF ceramic decoupling capacitor as close as possible to the VDD pin (pin 20) with a bulk 10 uF electrolytic or tantalum on the same node. For battery-powered designs using nanoWatt XLP modes, add a 1 uF reservoir on the LCD charge pump output if the application drives a high-segment-count LCD glass; the pump current can droop the supply during multiplex transitions. Estimated: a typical PIC16LF1938 design at 32 MHz draws ~5 mA, dropping to sub-1 uA in sleep with RTC running.
The 28-SOIC package has a theta_JA of approximately 50-60 C/W on a standard JEDEC 2-layer test board. Estimated: at full 32 MHz CPU speed and all peripherals enabled, power dissipation stays under 25 mW, so thermal rise is well under 5 C above ambient at 25 C - well within the 85 C industrial ceiling. No external heatsink or copper pour for thermal spreading is required for normal operation; however, ensure that the supply rail does not drop below 1.8 V under heavy CPU bursts on weak supplies.
Reserve PGC (RB6, pin 27) and PGD (RB7, pin 28) for ICSP (In-Circuit Serial Programming) access. Do NOT place pull-ups on these pins that exceed 10 kohm, as Microchip's programmers require the ability to drive them low. Place the 32.768 kHz crystal (if used for RTC) within 5 mm of the OSC1/OSC2 pins with short traces and a guard ground ring. For LCD applications, route the SEGx and COMx lines with adequate spacing from noisy digital lines to prevent ghost-segment flicker.
Do not confuse PIC16LF1938 with PIC16LF1939 (40/44-pin) or PIC16LF194x (64-pin) variants - the 28-SOIC package is unique to the 1938. When sourcing replacements, verify the package code: 'SO' denotes 28-SOIC, 'SS' denotes 28-SSOP (different footprint), 'ML' denotes 28-QFN, 'SP' denotes 28-SPDIP. According to the Microchip datasheet, the LF (low-voltage) variant's VDD must NOT exceed 3.6 V - using the LF variant in a 5 V design is a common mistake that destroys the part.
When using the integrated LCD driver, place the VLCD bypass capacitor (typically 1 uF) as close as possible to the VLCD pin (shared with a PORTC pin in the 28-SOIC variant). Keep the COMx traces short and balanced - the LCD datasheet section recommends matching trace lengths within 5 mm to prevent unequal RC delays that cause contrast non-uniformity. For capacitive touch (CPS module) on RB1-RB5, surround each touch pad with a guard trace tied to ground and do not run noisy digital lines under the touch electrodes.
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial -40C to +85C temperature grade but not AEC-Q100 qualified for automotive - choose PIC16F1938-E/SO extended grade variants or PIC16F1938-H/SO for harsher environments. Halogen-free and lead-free per Microchip environmental compliance disclosures.
