PCF8591T - 8-bit I2C ADC/DAC, 4-Ch Input | NXP Semiconductors
MPN: PCF8591T ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.1 | $4.10 |
| 10 | $3.65 | $36.50 |
| 100 | $2.95 | $295.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.05 | $2,050.00 |
PCF8591T Overview
What is an 8-bit data acquisition IC? A data acquisition (DAQ) IC is a mixed-signal integrated circuit that bridges the analog and digital domains, typically containing one or more analog-to-digital converters (ADCs) and sometimes digital-to-analog converters (DACs) along with a digital interface for a host microcontroller. Within the broader taxonomy, the PCF8591T is an 8-bit successive-approximation ADC with an 8-bit DAC, controlled via an I2C serial interface - falling into the category of low-speed, low-resolution, system-management data converters used for sensor reading, setpoint generation, and analog control loops in embedded designs.
Key features of the PCF8591T include four multiplexed single-ended analog inputs (or three differential inputs selectable via the control byte), one rail-to-rail analog output, three hardware address pins (A0-A2) allowing up to eight devices on the same I2C bus without glue logic, and a single 2.5V to 6V supply. The on-chip track-and-hold and successive-approximation ADC delivers 8-bit resolution at typical conversion rates suitable for sensor monitoring and process control. The DAC section can be configured for 4-quadrant multiplication when an external reference is supplied, enabling digitally controlled gain and offset in signal-conditioning paths.
Typical applications include battery monitoring, industrial process-variable sensing (temperature, pressure, flow), LED brightness and contrast control via the DAC, closed-loop analog control in HVAC and appliance designs, and hobbyist/educational platforms (Raspberry Pi and Arduino sensor shields). The wide supply range (2.5V-6V) and low standby current also suit portable instrumentation and remote sensor nodes.
When designing with the PCF8591T, ensure the I2C pull-ups are sized for the bus capacitance and clock speed, place a 0.1uF decoupling capacitor close to VDD, and respect the address-pin strapping (A0-A2) so multiple devices coexist on the same bus. The analog inputs are not 5V-tolerant above VDD; use a resistive divider or op-amp buffer when sensing higher voltages.
Drop-in alternatives for PCF8591T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PCF8591T/2,512
✅ Drop-In📋 Reference alternative (not in catalog)
PCF8591T/2,518
✅ Drop-In📋 Reference alternative (not in catalog)
PCF8591TD-T
✅ Drop-In📋 Reference alternative (not in catalog)
TPAFE0808
✅ Drop-In📋 Reference alternative (not in catalog)
PCF8591T Maximum Ratings & Electrical Characteristics
| Manufacturer | NXP Semiconductors |
| Part Number | PCF8591T |
| Function | 8-bit A/D and D/A converter (data acquisition IC) |
| Resolution | 8 bits (ADC and DAC) |
| Analog Inputs | 4 single-ended / 3 differential (multiplexed) |
| Analog Outputs | 1 (8-bit DAC) |
| Serial Interface | I2C-bus (2-wire, up to 8 devices on bus) |
| Hardware Address Pins | A0, A1, A2 (3 pins, 8 selectable addresses) |
| Supply Voltage (VDD) | 2.5 V to 6 V |
| Analog Supply (VSSA/VREF) | Single-supply, VREF pin for ADC/DAC reference |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | 16-pin SO (SO-16 / SOT162-1), surface mount |
| Package Type | Small-Outline (SO), 16 leads, SOT162-1 |
| Mounting Type | Surface Mount |
| MSL Level | 1 (per JEDEC J-STD-020) |
| Conversion Principle (ADC) | Successive Approximation with track/hold |
| DAC Topology | R-2R / multiplying, rail-to-rail output |
PCF8591T Pin Configuration
| Pin 1 | AIN0 — Analog input channel 0 (single-ended or diff +) |
| Pin 2 | AIN1 — Analog input channel 1 (single-ended or diff -) |
| Pin 3 | AIN2 — Analog input channel 2 (single-ended or diff +) |
| Pin 4 | AIN3 — Analog input channel 3 (single-ended or diff -) |
| Pin 5 | A0 — Hardware address bit 0 |
| Pin 6 | A1 — Hardware address bit 1 |
| Pin 7 | A2 — Hardware address bit 2 |
| Pin 8 | VSS — Digital ground (substrate connection) |
| Pin 9 | SDA — I2C-bus serial data (open-drain) |
| Pin 10 | SCL — I2C-bus serial clock |
| Pin 11 | OSC — Oscillator input/output (external RC or clock) |
| Pin 12 | EXT — Chip enable / oscillator control |
| Pin 13 | AGND — Analog ground (reference for VREF) |
| Pin 14 | VREF — Voltage reference for ADC and DAC |
| Pin 15 | AOUT — Analog output from on-chip DAC |
| Pin 16 | VDD — Positive supply (2.5 V to 6 V) |
Typical Applications
PCF8591T is suitable for 6 applications: Battery Management & Multi-Cell Monitoring, Industrial Process Variable Sensing, HVAC Setpoint & Damper Control, LED Brightness & Contrast Bias Generation, Raspberry Pi & Arduino Sensor Hubs, Portable Instrumentation & Remote Sensor Nodes.
Battery Management & Multi-Cell Monitoring
The PCF8591T fits battery management and multi-cell voltage monitoring because it offers four single-ended analog inputs on a single I2C addressable device. Each cell voltage is divided into the 0-VREF range through a high-impedance resistive divider, then digitized to 8-bit resolution by the on-chip successive-approximation ADC. With VREF tied to a stable 2.5-5V reference, the converter delivers reliable readings for state-of-charge estimation in 2S-4S Li-ion or 6V-12V lead-acid packs. Three hardware address pins let the designer stack up to eight PCF8591T devices for 32-cell telemetry without bus-collision glue logic. Power dissipation is minimal - the part draws single-digit mA from a 3.3V or 5V rail, suiting battery-powered IoT nodes.
Recommended
Industrial Process Variable Sensing
The PCF8591T is well suited for industrial process-variable sensing (temperature, pressure, flow) where multiple low-bandwidth analog transducers must be digitized and reported to a host microcontroller. Its four analog inputs handle 4-20 mA or 0-10 V transducer outputs after signal conditioning, while the I2C interface simplifies wiring back to a master PLC or industrial MCU. The 2.5 V-6 V supply range covers 24 V-derived 5 V and 3.3 V logic rails commonly found in industrial controllers. Three address pins permit up to eight PCF8591T devices on the same bus, allowing 32 channels per I2C segment without expanding the MCU's peripheral count.
Recommended
HVAC Setpoint & Damper Control
The PCF8591T supports HVAC setpoint generation and damper/valve control by combining an ADC for reading thermistor or RTD inputs and a DAC for driving an analog actuator. The single 8-bit DAC output can be buffered and scaled to a 0-10 V control signal, while the 4 ADC inputs simultaneously read supply-air temperature, return-air temperature, humidity sensors (after conditioning), and a setpoint potentiometer. The wide 2.5 V-6 V supply and industrial temperature grade (-40 C to +85 C) suit equipment-room environments. Three address pins allow multiple PCF8591T devices to address multi-zone systems on a single I2C bus.
Recommended
LED Brightness & Contrast Bias Generation
The PCF8591T generates analog bias voltages for LED brightness, contrast, or backlight intensity control via its single 8-bit DAC, while its ADC inputs can monitor ambient light sensors and feedback photodiodes. The DAC output rail-to-rail behavior drives op-amp-based current mirrors to set LED driver reference voltages; the ADC inputs close a brightness-control loop by digitizing a photodiode current-to-voltage converter. The I2C bus saves MCU GPIO pins and the SO-16 package fits inside compact display modules. The 2.5 V-6 V supply covers single-cell Li-ion and 5 V logic rails typical of portable display designs.
Recommended
Raspberry Pi & Arduino Sensor Hubs
The PCF8591T is a mainstay on Raspberry Pi and Arduino sensor-shield and breakout-board designs because it expands the MCU's analog I/O over the existing I2C bus. Hobbyist libraries (SunFounder, Adafruit-equivalent, etc.) abstract the I2C control-byte protocol for reading all four ADC inputs and writing the DAC. The 3.3 V or 5 V supply range matches both Raspberry Pi GPIO and Arduino UNO/Mega rails without level shifting. Multiple PCF8591T devices (via A0-A2 strapping) can stack on the same I2C bus to add 4-32 analog channels to a single Pi header.
Recommended
Portable Instrumentation & Remote Sensor Nodes
The PCF8591T suits portable instrumentation and remote sensor nodes because its single 2.5 V-6 V supply and low standby current match battery-powered designs, and its I2C interface minimizes wiring. The four ADC channels digitize battery voltage, sensor output, and two auxiliary inputs simultaneously, while the DAC generates excitation or setpoint signals. Three address pins let one I2C master poll multiple PCF8591T devices across a distributed sensing array. The SO-16 footprint and 0-70 C commercial / -40-+85 C industrial operating range suit outdoor and industrial field deployments.
Recommended
Recommended Products Summary
Engineering reference data for PCF8591T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PCF8591T/2,512 | PCF8591T/2,518 | PCF8591TD-T | TPAFE0808 | MAX1115EKA+T |
|---|---|---|---|---|---|---|
| Package | SO-16 (SOT162-1) | SO-16 (SOT162-1) - same | SO-16 (SOT162-1) - same | SO-16 (SOT162-1) - same | SO-16 - same footprint | SOT-23-8 (different) |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | Silan Microelectronics | Analog Devices |
| Function | 8-bit ADC + 8-bit DAC | 8-bit ADC + 8-bit DAC | 8-bit ADC + 8-bit DAC | 8-bit ADC + 8-bit DAC | 8-bit ADC + 8-bit DAC | 8-bit ADC only (single channel) |
| Analog Inputs | 4 (single-ended) / 3 (differential) | 4 / 3 | 4 / 3 | 4 / 3 | 4 / 3 (verify datasheet) | 1 (single channel) |
| Analog Outputs (DAC) | 1 (8-bit) | 1 | 1 | 1 | 1 (verify datasheet) | 0 (DAC not present) |
| Serial Interface | I2C | I2C | I2C | I2C | I2C | I2C |
Key Differentiators
- Integrated 4-input ADC + 1-output DAC in a single I2C device (vs MAX1115EKA+T (single-channel 8-bit ADC only))
- Three hardware address pins allow 8 devices per I2C bus (vs Most competing single-channel ADCs (single fixed I2C address))
- Wide 2.5 V-6 V supply covers 3.3 V and 5 V rails without level shifting (vs MAX1115EKA+T (2.7 V-5.5 V))
Design Notes
Power the PCF8591T from a clean 2.5 V to 6 V rail and place a 0.1 uF decoupling capacitor close to VDD (pin 16) to keep digital switching noise out of the analog domain. For best ADC/DAC linearity, derive VREF (pin 14) from a low-noise reference (e.g. a 2.5 V or 5 V bandgap reference) rather than tying VREF directly to VDD; supply noise on VREF directly couples into both conversion paths. AGND (pin 13) and VSS (pin 8) should be joined at a single star point under the IC to avoid ground-loop errors in the analog path.
SDA (pin 9) and SCL (pin 10) are open-drain and require external pull-ups sized for the bus capacitance; typical values are 4.7 kohm at 100 kHz and 2.2 kohm at 400 kHz for short buses. Keep the I2C traces short and parallel-routed, and avoid routing them near the analog inputs to prevent digital switching noise from coupling into ADC measurements. If the I2C master is at a different supply rail than the PCF8591T, use a proper I2C level translator rather than a resistive divider to avoid logic-level thresholds shifting with bus loading.
Do not drive the analog inputs (AIN0-AIN3) above VDD or below VSS; the absolute-max input range per the NXP datasheet is GND-0.5 V to VDD+0.5 V. Higher voltages require an external resistive divider or op-amp buffer. The control-byte auto-increment bit must be set correctly when reading more than one channel in a single I2C transaction - omitting it causes channel data to repeat. Finally, the OSC and EXT pins (11, 12) require careful selection of the external RC network per the datasheet's oscillator section; an incorrect RC value degrades ADC conversion timing accuracy.
Place the PCF8591T close to the analog signal sources to minimize trace-induced pickup, and keep analog traces away from switching power or I2C clock edges. Use a ground pour on the analog side and route digital lines (SDA, SCL, EXT) on the opposite side of the SO-16 package. If the design includes both a DIP-16 prototype footprint and an SO-16 production footprint, route them on a single PCB to allow easy migration - both share the same pinout per the NXP PCF8591 datasheet.
Compliance Information
RoHS / REACH / halogen-free status not explicitly stated in the provided web data for PCF8591T; refer to NXP product page or PCN documents for confirmation. Lead-free per SO-16 surface-mount package convention (NXP SO-package parts are Pb-free). AEC-Q100 not applicable (consumer/industrial grade, not automotive).
