PCA9420FUKZ - PMIC 2 Bucks + 2 LDOs + Charger | NXP
MPN: PCA9420FUKZ β Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
PCA9420FUKZ Overview
A power management IC (PMIC) is a specialized semiconductor device that integrates multiple power conversion and management functions - voltage regulators, battery chargers, and power sequencing - onto a single die. Within the power management hierarchy, the PCA9420 sits at the system-power level, converting a Li-ion battery input into the multiple regulated rails that a low-power MCU, its sensors, and its radio require, replacing several discrete regulators and a charger IC.
Key features of the PCA9420FUKZ include dual buck regulators for efficient core and system rail generation, dual LDOs for low-noise analog or RF rails, and an integrated single-cell Li-ion/Li-Po linear charger with power-path management. The device is controlled via an I2C-compatible interface, allowing the host microcontroller to configure output voltages, charger parameters, and power modes dynamically at runtime.
Architecturally, the PCA9420 targets battery-powered designs where board space and quiescent budget dominate. Integration of the charger and four regulated outputs into a 2.09 x 2.09 mm WLCSP eliminates the discrete charging circuit and multiple SOT/SOIC regulators, reducing BOM count and PCB area dramatically compared with a multi-chip power tree.
Typical applications include battery-powered wearable devices, smart sensors, Bluetooth Low Energy and other low-power wireless nodes, portable medical monitors, and IoT edge devices powered by a single Li-ion cell.
Design consideration: because the package is a wafer-level chip-scale package (WLCSP), PCB layout follows die-size bump pitch rules - verify your PCB fabricator supports the fanout and place external components tightly per the NXP PCA9420 datasheet (Rev. 4.2, July 2023) layout guidance.
This page synthesizes distributor availability, family-level drop-in options, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PCA9420FUKZ β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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PCA9421UKZ
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PCA9420UKZ
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View Datasheet βPCA9420FUKZ Specifications
| Function | Power Management IC (PMIC) for low-power microcontroller applications |
| Topology | 2 Buck + 2 LDO + Li-ion Charger |
| Input Source | Single-cell Li-ion / Li-Po battery |
| Buck Regulators | 2 |
| LDO Regulators | 2 |
| Battery Charger | Integrated linear charger, Li-ion |
| Control Interface | I2C-compatible serial interface |
| Package | 25-WLCSP (2.09 mm x 2.09 mm) |
| Mounting Type | Surface Mount (WLCSP) |
| Datasheet Revision | Rev. 4.2 - 26 July 2023 (Product data sheet) |
PCA9420FUKZ 25-wlcsp (2.09 mm x 2.09 mm) Pin Configuration Guide
Pin configuration for PCA9420FUKZ (25-wlcsp (2.09 mm x 2.09 mm) package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for PCA9420FUKZ.
Refer to the datasheet for full pin configuration.
Typical Applications
PCA9420FUKZ is suitable for 6 applications: Wearable Devices, Bluetooth Low Energy Sensor Nodes, Portable Medical Monitors, IoT Edge Devices, Smart Cards and Secure Tags, Handheld and Portable Instrumentation.
Wearable Devices
Wearable products such as fitness bands and smart rings are dominated by PCB area and battery capacity constraints, making the PCA9420FUKZ a strong fit. Its 2.09 mm x 2.09 mm 25-ball WLCSP occupies less board area than a single discrete SOT-23 regulator, while integrating the dual bucks, dual LDOs, and Li-ion charger that a wearable MCU, sensor suite, and BLE radio each require. The integrated 5V-input charger accepts USB charging paths directly, and I2C configurability lets firmware switch power modes between active sensing and sleep, directly extending battery life. Per the NXP PCA9420 datasheet, this PMIC family was explicitly targeted at low-power microcontroller applications powered by Li-ion cells - precisely the wearable architecture.
Recommended
Bluetooth Low Energy Sensor Nodes
BLE beacons and wireless sensor nodes spend most of their life in sleep, waking briefly to sample and transmit. The PCA9420FUKZ suits this profile: the two bucks efficiently step the Li-ion cell down to the MCU core and system rails during active bursts, while the two LDOs deliver low-noise analog rails for the sensor front end and radio. Quiescent-budget-critical sleep states are managed through the I2C interface, letting firmware disable or reconfigure rails between events. DigiKey's listing describes the part as a 5V 2 Buck + 2 LDO + Charger PMIC, confirming the USB/5V charging input needed for deployed nodes. According to the NXP PCA9420 product page, the family targets exactly this class of Li-ion-powered low-power application.
Recommended
Portable Medical Monitors
Portable and wearable medical monitors combine a low-power MCU, analog sensing circuitry, and a wireless uplink, all powered from a rechargeable Li-ion cell. The PCA9420FUKZ addresses this power tree in one chip: dual bucks generate the digital rails efficiently, dual LDOs supply the clean rails that biosensor analog front ends require, and the integrated charger with power-path management keeps the system alive while the battery charges from a 5V source. The 2.09 x 2.09 mm WLCSP supports miniaturized adhesive-patch and chest-strap form factors. I2C control enables firmware-driven power sequencing and fault monitoring appropriate for medical device power architectures, per the NXP PCA9420 datasheet (Rev. 4.2, July 2023).
Recommended
IoT Edge Devices
Battery-powered IoT edge nodes need a complete power system - charging, efficient step-down conversion, and clean analog rails - in minimal board area. The PCA9420FUKZ delivers all three functions: the integrated Li-ion linear charger accepts a 5V input as noted in DigiKey's product description, the two bucks convert the cell voltage to MCU and peripheral rails with switching efficiency, and the two LDOs provide low-noise supplies for RF and sensor circuitry. I2C control lets the node's firmware implement aggressive power gating between duty-cycled wakeups, a key determinant of multi-year battery life. The 25-ball WLCSP footprint of 2.09 mm x 2.09 mm fits coin-cell-sized or card-format edge hardware, per NXP's product positioning for low-power microcontroller applications.
Recommended
Smart Cards and Secure Tags
Battery-assisted smart cards, electronic shelf labels, and secure RFID tags are among the most space-constrained electronics in production, with power circuits squeezed under thin, flexible or rigid substrates. The PCA9420FUKZ's 2.09 x 2.09 mm WLCSP is thinner and smaller than any discrete multi-chip power solution, and its single-chip integration of charger, dual bucks, and dual LDOs minimizes assembly steps for high-volume card manufacturing. The Li-ion charger accepts a 5V input compatible with wireless or contact charging pads, while I2C configuration allows firmware to trim rail voltages to the exact needs of the secure element and display driver. Per the NXP PCA9420 datasheet, the device was architected for exactly these ultra-low-power microcontroller platforms.
Recommended
Handheld and Portable Instrumentation
Handheld meters, portable dataloggers, and compact test instruments run from single Li-ion cells and require multiple regulated rails with battery management built in. The PCA9420FUKZ consolidates that power tree: the dual bucks supply the MCU core and display/backlight system rails efficiently from the cell, the dual LDOs feed the precision analog front end and reference circuitry with low noise, and the integrated charger manages 5V-input recharging between uses. I2C-based control lets the instrument firmware report charger status and adjust rails with measurement mode, extending runtime. The 2.09 x 2.09 mm 25-ball WLCSP keeps the power section compact on crowded handheld PCBs, consistent with NXP's stated target of low-power microcontroller applications.
Recommended
Recommended Products Summary
Engineering reference data for PCA9420FUKZ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PCA9421UKZ | PCA9420UKZ |
|---|---|---|---|
| Package | 25-WLCSP (2.09x2.09 mm) | 25-WLCSP (2.09x2.09 mm) - same | 25-WLCSP (2.09x2.09 mm) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Buck Regulators | 2 | 2 | 2 |
| LDO Regulators | 2 | 2 | 2 |
| Battery Charger | Yes, Li-ion linear charger (5V input) | Yes, Li-ion charger | Yes, Li-ion charger |
| Control Interface | I2C-compatible | I2C-compatible | I2C-compatible |
| Target Application | Low-power MCU applications, Li-ion powered | Low-power MCU applications, Li-ion powered | Low-power MCU applications, Li-ion powered |
Key Differentiators
- Single-chip complete power system in 2.09 x 2.09 mm (vs PCA9421UKZ)
- Integrated Li-ion charger with 5V input (vs PCA9420UKZ)
- I2C runtime configurability (vs PCA9421UKZ)
Design Notes
The PCA9420FUKZ uses a 25-ball WLCSP (2.09 x 2.09 mm), so confirm early in the project that your PCB fabricator supports the ball pitch with via-in-pad or microvia fanout, and that your assembler handles WLCSP reflow. Follow the recommended land pattern and layout in the NXP PCA9420 datasheet (Rev. 4.2) exactly - WLCSP reliability depends on correct land pattern and under-bump stress management.
Keep the buck converter input and output capacitor loops as short as possible directly at the WLCSP balls to minimize switching loop inductance and EMI. Place the LDO output capacitors close to their balls as well. Route the I2C bus away from buck switch nodes; capacitive coupling into the control interface can cause register corruption during load transients. Per the datasheet layout guidance, use a solid ground plane under the device.
Do not assume the PCA9421 is a blind substitute for the PCA9420FUKZ: although the family shares architecture and package, the ordering-information table in the NXP PCA9420 datasheet defines per-suffix default register settings, I2C address, and feature configurations that differ. Also verify charger termination settings against your specific Li-ion cell specification before production - charger parameters are set via I2C and must match the cell datasheet.
Compliance Information
Compliance data was not present in the verified web data retrieved on 2026-09-13. Consult the NXP product page and datasheet Rev. 4.2 for RoHS/REACH declarations.
