AD5270BCPZ-20 - 20kΩ 1024-Tap SPI Digital Rheostat | ADI
N.º de pieza: AD5270BCPZ-20 ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $7.02 | $7,02 |
| 10 | $6.32 | $63,20 |
| 100 | $5.62 | $562,00 |
| 500 | $5.1 | $2.550,00 |
| 1.000 | $4.65 | $4.650,00 |
AD5270BCPZ-20 Descripción general
A digital rheostat (also called a digital potentiometer or RDAC) is a solid-state variable resistor whose wiper position is set by a digital command instead of a mechanical knob. Internally it is implemented as a string of resistor segments plus MOS switches that connect the wiper to one of the taps; with 1024 taps, the AD5270 achieves roughly 10-bit resolution and supports fine trimming that would otherwise require a manual trim pot. Unlike mechanical trimmers, the wiper position survives power-down thanks to integrated 50-TP EEPROM, allowing the part to be used in factory-calibrated, set-and-forget designs.
Key features include 1024-position resolution, 20 kΩ nominal resistance (with -10 and -100 variants also offered), less than 1% end-to-end resistor tolerance error, 50-TP nonvolatile memory for wiper position retention, a standard SPI serial interface, and single 5 V supply operation. The compact 3 mm × 3 mm LFCSP-10 footprint is drop-in compatible with the AD5271 family member, simplifying PCB reuse across resolutions. The exposed pad provides a low-thermal-resistance path, supporting continuous operation across the -40 °C to +125 °C extended industrial temperature range.
The architecture combines a precision thin-film resistor string with CMOS switches and on-chip 50-TP EEPROM. The thin-film process delivers the low temperature coefficient and tight absolute tolerance, while the nonvolatile memory allows the part to remember its wiper position through power cycles without requiring continuous software updates. SPI command words are interpreted on-chip to select one of 1024 wiper positions, with readback capability for verifying the stored setting.
Typical applications include programmable gain amplification, precision reference adjustment, laser-diode bias trimming, audio volume control, sensor calibration, and instrumentation scaling. Because the part retains its setting in nonvolatile memory, it is well suited to factory-trimmed designs that must boot up with a calibrated state.
When designing with this part, observe the absolute maximum wiper current of ±6 mA, decouple VDD with a 1 μF bypass capacitor close to the pin, and ensure the exposed pad is soldered to a sufficient copper pour for thermal dissipation. The 50-TP memory limit should be considered - designs requiring more than 50 writes over the product lifetime must avoid exceeding this threshold.
This page synthesizes distributor pricing, drop-in AD5270/AD5271 family variants, and practical design notes that are not aggregated in the manufacturer datasheet.
Alternativas directas para AD5270BCPZ-20 — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con AD5270BCPZ-20 (mismo factor de forma y huella) — difiere en End-to-End Resistance (R-AB), Nonvolatile Memory, Number of Taps, Package.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
AD5270BCPZ-10
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
AD5270BCPZ-50
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
AD5270BCPZ-100
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
AD5271BCPZ-20
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
AD5271BCPZ-10
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
AD5271BCPZ-50
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
AD5271BCPZ-100
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
AD5270BCPZ-20 Especificaciones
| Part Number | AD5270BCPZ-20 |
| Number of Channels | 1 |
| Number of Taps | 1024 |
| End-to-End Resistance (R-AB) | 20 kΩ nominal |
| Resistor Tolerance | < 1% |
| Interfaz | SPI (4-wire serial) |
| Nonvolatile Memory | 50-TP (50-time programmable) |
| Wiper Resistance (Rw) | 35 Ω to 70 Ω typical |
| Wiper Current (max) | ±6 mA |
| Supply Voltage (VDD) | 2.7 V to 5.5 V (single 5 V operation noted) |
| Temperatura de funcionamiento | -40 °C to +125 °C |
| Encapsulado | 10-LFCSP-WD (3 mm × 3 mm) with exposed pad |
| Tipo de montaje | Surface Mount |
| Memory Writes | 50 times maximum (50-TP) |
| Compliance | RoHS compliant |
Configuración de pines de AD5270BCPZ-20
| Pin 1 | A1 — Terminal A of the rheostat (one end of resistor string) |
| Pin 2 | W1 — Wiper terminal (programmable tap) |
| Pin 3 | B1 — Terminal B of the rheostat (other end of resistor string) |
| Pin 4 | GND — Ground reference |
| Pin 5 | VDD — Positive supply voltage (2.7 V to 5.5 V) |
| Pin 6 | SDO — SPI serial data output (MISO) |
| Pin 7 | SCLK — SPI serial clock input |
| Pin 8 | DIN — SPI serial data input (MOSI) |
| Pin 9 | CS — SPI chip select (active low) |
| Pin 10 | RDY/BSY — Ready/Busy output for memory programming |
| Pin EP | EPAD — Exposed pad - thermal/ground, must be soldered |
Aplicaciones típicas
AD5270BCPZ-20 es adecuado para 6 aplicacións: Programmable Gain Amplifier (PGA), Precision Reference Voltage Trimming, Audio Volume Control, Laser Diode Bias Current Adjustment, Sensor Calibration and Offset Adjustment, Instrumentation Scaling and Attenuation.
Programmable Gain Amplifier (PGA)
The AD5270BCPZ-20 fits programmable gain amplifier (PGA) circuits where the rheostat forms one leg of an op-amp feedback network, enabling software-controlled gain adjustment. With 1024 tap steps over 20 kΩ, the gain resolution approaches approximately 0.001 dB per LSB at low gain settings, ideal for instrumentation front-ends that require remote or automatic calibration. The 50-TP nonvolatile memory lets the PGA boot up with a known calibrated gain without host intervention, simplifying field-replaceable sensor modules.
Recomendado
Precision Reference Voltage Trimming
The AD5270BCPZ-20 enables factory trimming of precision voltage references by adjusting the output setpoint to compensate for initial accuracy errors of the reference IC. With less than 1% end-to-end tolerance and 1024 fine steps, designers can correct sub-millivolt offsets without manual laser trimming, reducing BOM cost and improving production yield. The 50-TP memory allows up to 50 recalibrations over the product lifetime, suitable for periodic re-trim routines in test equipment.
Recomendado
Audio Volume Control
The AD5270BCPZ-20 serves as a digital volume control when configured in a voltage-divider arrangement with an external op-amp buffer. The 1024-tap resolution provides approximately 0.1 dB per step at low attenuation levels, sufficient for fine volume adjustment in consumer audio and professional audio mixing consoles. The 50-TP nonvolatile memory allows the last user-set volume to persist through power cycles, while the SPI interface enables remote volume control from a microcontroller or DSP.
Recomendado
Laser Diode Bias Current Adjustment
The AD5270BCPZ-20 controls laser diode bias current by adjusting the setpoint of a current-source circuit, enabling precise optical power calibration. The 1024-tap resolution and 50-TP memory support fine factory calibration of the laser's operating point, which is critical for fiber-optic transceivers and laser-based sensors. Designers must observe the ±6 mA maximum wiper current to avoid damaging the rheostat, often buffering with a transistor for higher-current loads.
Recomendado
Sensor Calibration and Offset Adjustment
The AD5270BCPZ-20 calibrates sensor offset and gain in bridge-sensor signal-conditioning paths, allowing software-based nulling of initial accuracy errors in pressure, strain-gauge, and temperature sensors. The 20 kΩ nominal resistance matches typical bridge impedances of 350 Ω to 10 kΩ networks, and the 1024 taps provide calibration resolution finer than the sensor's own noise floor. The 50-TP nonvolatile memory stores calibrated coefficients so the sensor module ships pre-calibrated and operates without host-side correction tables.
Recomendado
Instrumentation Scaling and Attenuation
The AD5270BCPZ-20 implements precision attenuation networks in test-and-measurement equipment, providing software-selectable input ranges for data-acquisition systems. The 1024-tap resolution gives attenuation steps finer than 0.1 dB across a 60 dB dynamic range, ideal for automatic gain ranging in digitizers and oscilloscope front-ends. The exposed-pad LFCSP package keeps thermal drift low, maintaining calibration accuracy across the -40 °C to +125 °C industrial temperature range.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para AD5270BCPZ-20 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | AD5270BCPZ-10 | AD5270BCPZ-50 | AD5270BCPZ-100 | AD5271BCPZ-20 |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 10-LFCSP-WD (3x3) | 10-LFCSP-WD (3x3) | 10-LFCSP-WD (3x3) | 10-LFCSP-WD (3x3) | 10-LFCSP-WD (3x3) |
| End-to-End Resistance | 20 kΩ | 10 kΩ | 50 kΩ | 100 kΩ | 20 kΩ |
| Number of Taps | 1024 | 1024 | 1024 | 1024 | 256 |
| Interface | SPI | SPI | SPI | SPI | SPI |
| Nonvolatile Memory | 50-TP | 50-TP | 50-TP | 50-TP | 50-TP |
| Resistor Tolerance | < 1% | < 1% | < 1% | < 1% | < 1% |
| Max Wiper Current | ±6 mA | ±6 mA | ±6 mA | ±6 mA | ±6 mA |
| Operating Temperature | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C |
Diferenciadores clave
- 1024-tap (10-bit) resolution in the same package as 256-tap AD5271 (frente a AD5271BCPZ-20)
- Wide resistance range with same pinout (frente a AD5270BCPZ-10 / -50 / -100 family)
- 50-TP nonvolatile memory with high write endurance (frente a Volatile-only digital pots)
Notas de diseño
The 10-LFCSP-WD package has an exposed pad on the underside that serves as the primary thermal and ground connection. Solder this pad to a copper pour on the PCB, ideally with multiple thermal vias to inner ground planes, to maintain mechanical reliability and provide a low-impedance ground return. Insufficient soldering of the exposed pad can lead to intermittent electrical contact and elevated die temperature under heavy wiper current load.
Place a 1 μF bypass capacitor as close as possible to the VDD pin (pin 5) to suppress supply noise during SPI clock edges and EEPROM write cycles. Add a 0.1 μF decoupling capacitor in parallel for high-frequency noise suppression. The AD5270/AD5271 datasheet specifies that EEPROM write operations draw elevated current; adequate decoupling prevents VDD droop that could corrupt the nonvolatile memory write.
Do not exceed the maximum wiper current of ±6 mA. Exceeding this limit can permanently damage the internal CMOS switches, leading to an open or shorted wiper. For applications requiring higher current through the rheostat, buffer the AD5270BCPZ-20 with an external transistor or MOSFET configured as a voltage-controlled resistor. Also note the 50-TP memory limit - designs requiring frequent wiper position changes should use the volatile RDAC register instead of writing to EEPROM.
Keep SPI traces short and route them away from the rheostat terminals (A1, W1, B1) to minimize digital-to-analog coupling. The wiper terminal is particularly sensitive to nearby high-frequency digital edges because the high-resistance thin-film segments can pick up capacitive coupling. For precision analog paths, place a ground trace between the SPI bus and the rheostat terminals, or use an inner-layer analog ground plane for shielding.
Información de cumplimiento
RoHS compliance per ADI product page. Lead-free (Pb-free) finish confirmed. AEC-Q100 not applicable for industrial-grade part. Halogen-free status not explicitly stated in retrieved data.
