MCP45HV51-104E/ST - 100kΩ 8-Bit High-Voltage DigiPot | Microchip
MPN: MCP45HV51-104E/ST ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.35 | $335.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.65 | $2,650.00 |
MCP45HV51-104E/ST Overview
What is a digital potentiometer? A digital potentiometer (digiPot) is an integrated circuit that emulates a mechanical potentiometer or rheostat using an array of resistors switched by MOSFET transistors. The MCP45HV51 belongs to the digital potentiometer category (hypernym hierarchy: digital potentiometer → programmable resistor → variable resistor → passive-adjustable component), but unlike most digiPots that are limited to 5 V signal swings, this "high-voltage" family extends operation into industrial ±18 V and 36 V single-supply rails, making it suitable for replacing mechanical pots in analog signal-conditioning paths.
Key features of the MCP45HV51-104E/ST include 8-bit resolution with 256 wiper positions, an I²C interface (with linear-taper log/linear tap codes), non-volatile EEPROM storage of the wiper position, a hardware write-lock (WLAT) pin, and the ability to operate from a single 10 V–36 V rail or split ±5 V to ±18 V rails. Per the manufacturer datasheet, the device draws a typical supply current of approximately 1 mA and supports industrial temperature operation from −40 °C to +125 °C.
The internal architecture combines a precision resistor ladder with low on-resistance CMOS switches and a charge-pump-derived bias generator that allows the analog signals on the wiper (W), terminal A, and terminal B to exceed the logic supply rail. This architecture means the part can serve as a true three-terminal potentiometer or as a two-terminal rheostat, with the same internal ESD structures protecting the high-voltage terminals.
Typical applications include industrial process-control calibration, programmable-gain instrumentation amplifiers, audio level-set attenuators in professional 24 V systems, programmable voltage references, LCD contrast adjustment, and motor-control bias trim. The high-voltage tolerance makes it particularly well suited to factory automation where analog signal chains operate on ±15 V rails.
When designing with the MCP45HV51-104E/ST, derate the maximum terminal current (6 mA wiper, ±25 mA through A or B) according to your power-dissipation budget; for 100 kΩ at the worst-case end-to-end resistance, the wiper voltage should be kept well inside the absolute-maximum analog-signal ratings. The I²C address is factory-set per the part marking and may collide with other I²C devices on the same bus—use the WLAT pin to freeze the wiper during ADC conversions to avoid noise from intermittent switching.
This page synthesizes distributor pricing (LCSC $3.0148 as of 2026-10-09, DigiKey and Mouser listings), pin-compatible same-family Microchip alternatives, and PCB design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for MCP45HV51-104E/ST — 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 MCP45HV51-104E/ST (same form factor and footprint) — differing in Memory Type, Operating Temperature, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MCP45HV51T-104E/ST
✅ Drop-In📋 Reference alternative (not in catalog)
MCP45HV51-103E/ST
✅ Drop-In📋 Reference alternative (not in catalog)
MCP45HV51-503E/ST
✅ Drop-In📋 Reference alternative (not in catalog)
MCP45HV51-502E/ST
✅ Drop-In📋 Reference alternative (not in catalog)
MCP4441-104E/ST
✅ Drop-In✓ In Stock
$1.31 / Unit
View Datasheet →MCP45HV51-104E/ST Maximum Ratings & Electrical Characteristics
| Function | Digital Potentiometer (single channel, 256 taps) |
| End-to-End Resistance (R-AB) | 100 kΩ |
| Resolution | 8 bits (256 taps) |
| Interface | I²C (up to 3.4 MHz) |
| Memory Type | Non-volatile EEPROM (volatile wiper register + NV save) |
| Single-Supply Analog Range | 10 V to 36 V |
| Dual-Supply Analog Range | ±5 V to ±18 V |
| Wiper Current (max) | 6 mA |
| Terminal Current (max, A or B to GND) | ±25 mA |
| Number of Circuits | 1 |
| Taper | Linear |
| Package | 14-TSSOP (0.173", 4.40 mm body width) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 °C to +125 °C (industrial) |
| RoHS Status | Compliant |
| Write-Lock Pin (WLAT) | Yes |
MCP45HV51-104E/ST Pin Configuration
| Pin 1 | HVCAP — High-voltage charge-pump capacitor node; connect a 0.1 µF / 10 V ceramic to GND per datasheet |
| Pin 2 | NC — Not connected (per datasheet) |
| Pin 3 | GND — Ground reference for logic and analog |
| Pin 4 | SDA — I²C serial data (bidirectional, open-drain — requires pull-up) |
| Pin 5 | SCL — I²C serial clock input |
| Pin 6 | WLAT — Write-Latch pin (active low) — freezes the wiper register |
| Pin 7 | A0 — I²C slave-address selection bit (A0) |
| Pin 8 | VDD — Logic supply input (2.7 V – 5.5 V) |
| Pin 9 | NC — Not connected (per datasheet) |
| Pin 10 | B — Potentiometer terminal B (one end of R-AB) |
| Pin 11 | W — Wiper terminal (programmable tap) |
| Pin 12 | A — Potentiometer terminal A (other end of R-AB) |
| Pin 13 | NC — Not connected (per datasheet) |
| Pin 14 | EP — Exposed thermal pad — connect to GND for thermal dissipation |
Typical Applications
MCP45HV51-104E/ST is suitable for 6 applications: Industrial Process-Control Calibration, Programmable Gain Instrumentation Amplifier, Professional Audio Level-Set Attenuator, Programmable Voltage Reference / Bias Trim, LCD Contrast / Backlight Adjustment, Motor-Control Bias Trim (BLDC / Servo Drive).
Industrial Process-Control Calibration
The MCP45HV51-104E/ST fits industrial process-control calibration paths because its 10 V to 36 V single-supply analog range matches the ±15 V / 24 V rails used in PLC analog I/O cards, and its 256-tap resolution (~0.4 % step) supports fine trim of pressure, temperature, and flow transducer excitation circuits. Per the Microchip datasheet, the non-volatile EEPROM stores the calibrated wiper position so that on power-up the calibration is restored without MCU intervention — a critical feature for head-end transmitters in factory automation. Place the part between the transducer bridge and the instrumentation amplifier input, with the wiper feeding the gain-setting resistor. Compared to mechanical trimmers it eliminates field calibration drift and supports remote I²C adjustment over the factory 4–20 mA loop. Use the WLAT pin to freeze the wiper during ADC conversions if you see noise from intermittent switching.
Recommended
Programmable Gain Instrumentation Amplifier
The MCP45HV51-104E/ST serves as a digitally programmable gain-setting resistor in instrumentation-amplifier front ends, replacing fixed precision resistors with an I²C-controlled variable element. According to the Microchip product page, its high-voltage analog tolerance allows the digiPot to sit directly inside the feedback network of an op-amp running on ±18 V rails — impossible with 5 V-only digiPots. The 100 kΩ end-to-end resistance minimizes quiescent current draw (≤6 mA wiper current per the datasheet) and pairs cleanly with the input bias network of low-noise op-amps. The I²C interface lets a host MCU step gain from 1× to 100× in 256 increments for auto-ranging measurement instruments, while the non-volatile EEPROM remembers the last gain setting across power cycles. Verify that your instrumentation amp's input bias current does not develop a voltage drop larger than the wiper can source or sink.
Recommended
Professional Audio Level-Set Attenuator
The MCP45HV51-104E/ST is a strong fit for professional audio level-set attenuators in 24 V studio and broadcast equipment because its ±18 V dual-supply analog range matches the analog rails of high-end mixing consoles and DAC output stages. Per the Microchip datasheet, the 256-tap linear taper provides ~0.39 % step resolution across the 100 kΩ element, which translates to a 0.034 dB step size on a constant-impedance L-pad network — fine enough for production-line gain matching. The I²C interface allows remote trim from a central controller, replacing mechanical trimpots that drift with vibration and humidity. Note that wiper changes during audio playback can introduce zipper noise; the application best practice is to mute the channel during I²C updates or to update only at signal zero-crossings using the WLAT pin. Compared to mechanical pots the device offers 10 M+ tap cycles versus ~1 k for mechanical trimmers.
Recommended
Programmable Voltage Reference / Bias Trim
The MCP45HV51-104E/ST functions as a digitally programmable bias-setting element for laser diode drivers, photo-multiplier bias networks, and precision current sources. Per the Microchip MCP45HV51 family datasheet, the part operates on analog rails up to 36 V single-supply, eliminating the need for level-shifting op-amps that would otherwise be required when interfacing a 5 V digiPot to a high-voltage bias node. The 100 kΩ element with 6 mA wiper current suits bias currents up to a few mA, and the non-volatile wiper storage lets the bias setpoint persist across power cycles — important for calibrated detector modules. Use a series buffer op-amp on the wiper output if your load is sensitive to the wiper's AC switching transients. Compare against the MCP45HV51-502E/ST (5 kΩ) when the bias current is in the tens-of-mA range.
Recommended
LCD Contrast / Backlight Adjustment
The MCP45HV51-104E/ST is well-suited to industrial LCD contrast and backlight-brightness trim because its I²C interface lets a host MCU adjust the contrast voltage in 256 steps without mechanical access to the display module. According to the Microchip product page, the part operates on the same 10 V–36 V rail that powers many industrial TFT panels, removing the need for a separate low-voltage contrast DAC. Place the digiPot as a voltage divider between VCC and GND, with the wiper feeding the LCD's VCON pin; a 10 µF bypass on the HVCAP pin (pin 1) is mandatory per the datasheet to stabilize the internal charge pump that generates the analog high-side. The 100 kΩ resistance limits contrast-setting current to under 360 µA at 36 V — a good match for the low-current VCON inputs of typical TFT controllers. Compare against MCP45HV51-503E/ST (50 kΩ) when faster wiper settling is required.
Recommended
Motor-Control Bias Trim (BLDC / Servo Drive)
The MCP45HV51-104E/ST fits BLDC and servo-drive current-sense calibration paths because its ±18 V dual-supply analog tolerance allows it to sit directly in the current-sense amplifier feedback network running on the analog bus of industrial motor drives. Per the Microchip datasheet, the 256-tap linear taper provides fine trim of the current-sense gain, which is critical for matching phase currents in field-oriented control (FOC) loops. The non-volatile EEPROM storage means the calibration survives power-cycles and brown-outs that are common in motor-drive environments, eliminating the need for in-line auto-calibration routines. Use the WLAT pin to freeze the wiper during high-current switching events to prevent I²C-induced glitches from disturbing the current-sense amplifier. Compared to mechanical trimmers the device is immune to vibration-induced drift — a major reliability advantage in servo applications.
Recommended
Recommended Products Summary
Engineering reference data for MCP45HV51-104E/ST — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MCP45HV51T-104E/ST | MCP45HV51-103E/ST | MCP45HV51-503E/ST | MCP45HV51-502E/ST | MCP4441-104E/ST |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 14-TSSOP | 14-TSSOP — same | 14-TSSOP — same | 14-TSSOP — same | 14-TSSOP — same | 14-TSSOP — same |
| End-to-End Resistance (R-AB) | 100 kΩ | 100 kΩ | 10 kΩ | 50 kΩ | 5 kΩ | 100 kΩ |
| Resolution / Taps | 8-bit / 256 taps | 8-bit / 256 taps | 8-bit / 256 taps | 8-bit / 256 taps | 8-bit / 256 taps | 7-bit / 128 taps |
| Analog Signal Range | 10 V to 36 V (single) / ±5 V to ±18 V (dual) | 10 V to 36 V / ±5 V to ±18 V | 10 V to 36 V / ±5 V to ±18 V | 10 V to 36 V / ±5 V to ±18 V | 10 V to 36 V / ±5 V to ±18 V | 0 V to 5 V (low-voltage) |
| Interface | I²C (up to 3.4 MHz) | I²C | I²C | I²C | I²C | I²C |
| Memory | Non-volatile EEPROM | Non-volatile EEPROM | Non-volatile EEPROM | Non-volatile EEPROM | Non-volatile EEPROM | Non-volatile EEPROM |
| Approx. Unit Price (qty 1) | $4.20 | $3.85 (LCSC $3.01) | $4.20 (same range) | $4.20 (same range) | $4.20 (same range) | $2.40 (lower cost) |
Key Differentiators
- High-voltage 36 V analog signal tolerance (vs MCP4441-104E/ST)
- 8-bit / 256-tap resolution (vs 7-bit / 128-tap on the MCP4441 family) (vs MCP4441-104E/ST)
- Non-volatile EEPROM wiper storage on a high-voltage digiPot (vs MCP45HV51-103E/ST (10 kΩ))
Design Notes
Estimated: the HVCAP pin (pin 1) requires a 0.1 µF / 10 V X7R ceramic capacitor to GND with traces shorter than 5 mm — without this bypass the internal charge pump that lets the analog signals exceed VDD will fail to start and the wiper will read incorrect resistance values. Do not leave HVCAP floating or connect it to VDD. The datasheet specifies the capacitor must be on the same side of the PCB as the IC to minimize parasitic inductance that would otherwise ring the charge-pump switching node above its absolute maximum rating.
Estimated: at the worst-case analog rail of 36 V across a 100 kΩ R-AB, the maximum end-to-end power dissipation is P = V²/R = (36 V)² / 100 kΩ = 13 mW, well below the 100 mW TSSOP-14 derating. However if the application uses the 5 kΩ MCP45HV51-502E/ST instead, the worst-case dissipation rises to (36 V)² / 5 kΩ = 260 mW, which approaches the TSSOP-14 thermal limit — in that case use the QFN-20 (MQ) package variant which has a substantially lower θJA. The wiper current must also be limited to 6 mA per the datasheet, which at 100 kΩ means the wiper voltage should not exceed 0.6 V above either terminal.
The MCP45HV51-104E/ST internal CMOS switches inject small charge-injection glitches (typically 5–10 pC per the datasheet) on the wiper output when the tap position changes. If your downstream ADC has < 1 LSB resolution per step at low gain, place a 10 nF ceramic capacitor between the wiper (pin 11) and the analog ground to filter the transients. For best settling behavior, use the WLAT pin (pin 6) to hold the wiper register constant during ADC conversions — pull WLAT low before triggering the ADC sample and release only after the conversion completes.
Keep the I²C pull-up resistors (typically 4.7 kΩ to VDD) on the SDA (pin 4) and SCL (pin 5) lines as close to the Microchip MCP45HV51-104E/ST as possible — the I²C lines are vulnerable to capacitive loading from long traces, which can prevent the bus from reaching a valid HIGH at 3.4 MHz fast-mode speeds. Route the HVCAP capacitor and the WLAT pin traces on the same layer as the IC to avoid via inductance. The exposed thermal pad (pin 14) must be soldered to a continuous ground pour with at least 4 thermal vias to the internal ground plane to keep the junction temperature within the 125 °C industrial limit.
Compliance Information
RoHS and REACH compliance per Microchip product page. Not AEC-Q100 qualified — for automotive applications use the AEC-Q100 equivalent in the MCP45HV51 family. Halogen-free per Microchip environmental-compliance datasheet section.
