MCP41100-E/P - 100k 8-Bit SPI Digital Potentiometer | Microchip Technology
MPN: MCP41100-E/P ✓ Hoạt độngMCP41100-E/P Tóm tắt
A digital potentiometer is an electronic substitute for a mechanical potentiometer: an internal resistor ladder is terminated by the wiper terminal, and the tap position is stored as a code in an internal shift register rather than being set by a mechanical knob. In the taxonomy of parts, a digital pot sits between a passive potentiometer and a programmable gain element, and it belongs to the wider category of sensor and signal-conditioning ICs used for gain control, offset trimming and user-adjustable calibration.
Key features of the MCP41100-E/P include 256 taps with linear track taper, plus or minus 1 LSB maximum integral nonlinearity and differential nonlinearity, and a standard SPI serial interface supporting modes 0,0 and 1,1. The device also provides a software shutdown command that disconnects the A terminal from the resistor stack while connecting the wiper to the B terminal, which minimizes current draw in low-power states.
Internally, the part combines a 256-element resistive ladder with a CMOS wiper multiplexer and an 8-bit serial register. Writing one byte over SPI transfers the new wiper code, and the wiper settles to the selected tap without mechanical wear, contact bounce or hysteresis, which makes the part suitable for calibration data that must be stored and recalled repeatedly.
Typical uses include audio amplifier gain staging, sensor instrumentation and test-and-measurement front ends, power supply feedback trimming, and general gain or attenuation control where a manual potentiometer would be impractical or where setpoints must be changed by firmware.
When laying out a board around this device, keep the SPI traces short, add pull-ups on chip select where needed, and confirm that the wiper current drawn by the load stays within the rated wiper current so that the tap resistance does not introduce added nonlinearity.
This page combines manufacturer specifications, drop-in alternatives, a parameter-by-parameter comparison table and practical design notes so that you can evaluate the MCP41100-E/P against other SPI digital potentiometers before committing a design to production.
Bộ thay thế dễ dàng lắp đặt cho MCP41100-E/P — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với MCP41100-E/P (cùng hình factor và footprint) — khác nhau ở Device Type, Number of Channels, Resolution, Serial Interface, Shutdown Feature.
MCP41100-I/P
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →MCP41080-E/P
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
MCP41080-I/P
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
MCP41100-E/P Tỷ lệ tối đa & tính chất điện
| Device Type | Single-channel digital potentiometer (8-bit) |
| End-to-End Resistance | 100 kOhm |
| Number of Taps | 256 |
| Độ phân giải | 8 bits |
| Track Taper | Linear |
| Integral Nonlinearity (INL) | plus or minus 1 LSB maximum |
| Differential Nonlinearity (DNL) | plus or minus 1 LSB maximum |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Static Supply Current | 1 uA maximum |
| Serial Interface | SPI, modes 0,0 and 1,1 |
| Number of Channels | 1 |
| Number of Potentiometers | 1 |
| Hộp | 8-pin PDIP |
| Kiểu lắp đặt | Through-hole |
| Shutdown Feature | Software shutdown via SPI command |
Cấu hình chân MCP41100-E/P
| Chân 1 | VSS — Ground reference for the device |
| Chân 2 | VDD — Positive supply input, 2.7 V to 5.5 V |
| Chân 3 | CS — Chip select, active low, frames the SPI transfer |
| Chân 4 | SCK — SPI serial clock input |
| Chân 5 | SDI — SPI serial data input (MOSI) |
| Chân 6 | PA — Terminal A of the resistor ladder |
| Chân 7 | PW — Wiper output of the resistor ladder |
| Chân 8 | PB — Terminal B of the resistor ladder |
Ứng dụng tiêu biểu
MCP41100-E/P phù hợp cho 6 Áp dụngs: Audio Amplifier Gain Control, Sensor Instrumentation and Calibration Trim, Test and Measurement Front-Panel Control, Power Supply Feedback Trimming, Programmable Gain and Filter Tuning, IoT and Embedded Control Nodes.
Audio Amplifier Gain Control
The MCP41100-E/P fits audio gain staging where a signal chain needs several selectable attenuation or gain positions without mechanical controls. The 100 kOhm ladder sits comfortably with the input impedance of common audio op-amp stages, and the 256 taps at 8-bit resolution give 0.4 percent nominal steps, which is finer than most listener-perceptible gain differences. Because the wiper position is held in a digital register, the selected channel or program can be recalled instantly by the host microcontroller over SPI, avoiding the click and settling time of switching a mechanical pot. The linear taper also means the wiper code maps directly onto a dB or voltage gain table in firmware.
Được đề xuất
Sensor Instrumentation and Calibration Trim
In instrumentation front ends, the MCP41100-E/P provides a firmware-adjustable calibration element next to the sensor bridge. The plus or minus 1 LSB maximum INL and DNL of the 100 kOhm version keep tap error at roughly 0.4 percent of full scale, which is acceptable for coarse zero and gain calibration where a higher resolution trim would add cost for little benefit. The part consumes less than 1 uA in static operation and can be placed in shutdown between measurements, so it suits battery-powered data loggers that sample infrequently. The SPI interface lets a microcontroller store the calibration coefficient in non-volatile memory and reapply it at every boot.
Được đề xuất
Test and Measurement Front-Panel Control
The MCP41100-E/P is a natural fit for instrument front panels and calibration fixtures where an operator or remote host needs to adjust a reference level without opening the enclosure. Because the tap is addressable over SPI, a host computer can store test profiles, sweep the wiper through all 256 positions during calibration, and read back the final setting. The through-hole 8-pin PDIP package is convenient for hand-wired prototypes and legacy instrument boards that were not designed for fine-pitch surface-mount parts. The 2.7 V to 5.5 V supply range covers both legacy 5 V analog sections and modern 3.3 V control sections in the same instrument.
Được đề xuất
Power Supply Feedback Trimming
In power supply designs, the MCP41100-E/P can trim a feedback divider or reference network so that a board-level output lands on its nominal value without a manual adjust pot. The device operates from the same 2.7 V to 5.5 V window used by most secondary rails, and its software shutdown keeps the trim network from loading the circuit when the supply is disabled. Because the trim value is stored as a code, a factory calibration routine can sweep the wiper, measure the output with an ADC, and write the best tap permanently into the product's memory. The 100 kOhm ladder is a practical match for typical high-impedance feedback dividers.
Được đề xuất
Programmable Gain and Filter Tuning
The MCP41100-E/P allows gain and cutoff points to be tuned in the field rather than fixed at build time. In an RC or Sallen-Key filter, placing the pot in the feedback or grounding path lets a host MCU set the corner frequency over 256 steps, which is far more granular than a conventional 22-step trimmer. The plus or minus 1 LSB maximum DNL means the step size is predictable, so the firmware can convert a requested frequency into a tap code with a simple linear mapping. The device also tolerates being driven while the system is in shutdown, since the shutdown command isolates the A terminal rather than leaving the ladder floating.
Được đề xuất
IoT and Embedded Control Nodes
In IoT and embedded control nodes, the MCP41100-E/P lets a microcontroller adjust a physical variable remotely, such as a light dimming level or a motor speed reference, without adding a rotary encoder or a mechanical pot to the enclosure. The part's less than 1 uA static current and software shutdown support battery operation, since the trim network can be powered down between adjustments. The SPI interface runs from the same microcontroller that drives the communications radio, so no separate analog adjustment hardware is needed. The 8-pin PDIP footprint also suits through-hole industrial control boards and hand-assembled prototypes that are not surface-mount capable.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MCP41100-E/P — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | MCP41100-I/P | MCP41080-E/P | MCP41080-I/P |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-pin PDIP | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin PDIP - same |
| End-to-End Resistance | 100 kOhm | 100 kOhm - identical | 80 kOhm (-20 percent) | 80 kOhm (-20 percent) |
| Resolution / Taps | 8 bits / 256 taps | 8 bits / 256 taps - identical | 8 bits / 256 taps | 8 bits / 256 taps |
| Track Taper | Linear | Linear | Linear | Linear |
| Serial Interface | SPI, modes 0,0 and 1,1 | SPI, modes 0,0 and 1,1 | SPI, modes 0,0 and 1,1 | SPI, modes 0,0 and 1,1 |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Number of Channels | 1 | 1 | 1 | 1 |
| Static Supply Current | 1 uA maximum | 1 uA maximum | 1 uA maximum | 1 uA maximum |
| Temperature Grade Designation | -E grade | -I grade, different grade suffix | -E grade | -I grade, different grade suffix |
Bảo phân biệt quan trọng
- Only listed alternative with an identical 100 kOhm ladder and identical electrical behaviour (vsMCP41080-E/P)
- Same 8-pin PDIP footprint as the target, so no PCB change is required (vsMCP41100-E/SN)
- Linear track taper makes wiper code map directly onto a resistance or gain value (vsMCP41100-I/P)
Ghi chú thiết kế
Place the MCP41100-E/P close to the circuit that uses the wiper. The wiper and ladder terminals are the only analog signals on the board, and long traces between PW and the receiving amplifier pick up noise and stray capacitance. Keep the SPI lines (CS, SCK, SDI) short and route them away from the wiper trace; if the board has a switching supply or a fast digital bus nearby, route the wiper between a ground guard trace and the component it feeds. A solid ground plane under the DIP body also helps because VSS is a dedicated pin at one end of the package.
Decouple the supply pin with a 0.1 uF ceramic capacitor as close as possible to pin 2, and add 1 uF to 10 uF of bulk capacitance on the rail if the wiper load changes quickly. The device draws less than 1 uA in static operation, so supply current is usually dominated by the load connected to the wiper rather than by the IC. Use the software shutdown command between measurement bursts to isolate the A terminal and tie the wiper to the B terminal, which prevents leakage through the ladder from disturbing a high-impedance node during long idle periods.
The most common mistake is forgetting that the SPI transfer is two bytes: a command byte followed by a data byte carrying the wiper code. Sending only a data byte shifts the wrong word into the command register and the wiper does not move. Also confirm the SPI mode against your controller configuration, since the device supports modes 0,0 and 1,1 but not mode 1,0. Finally, do not exceed the wiper current rating when driving a load, because excessive wiper current adds distortion to the tap resistance and degrades the plus or minus 1 LSB linearity the part is specified to deliver.
Thông tin tuân thủ
Microchip product pages and the family data sheet list RoHS and material composition declarations, but the status for this specific part and package code was not captured in this record, so each field is left as unknown. The device is a commercial-grade catalog item rather than an AEC-Q100 qualified automotive part.
