PCA9420 - PMIC 2 Buck + 2 LDO + Li-ion Charger | NXP
MPN: PCA9420 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.66 | $26.60 |
| 100 | $2.24 | $224.00 |
| 500 | $1.98 | $990.00 |
| 1,000 | $1.75 | $1,750.00 |
PCA9420 Overview
A Power Management IC (PMIC) is a specialized voltage regulator subsystem that integrates multiple power conversion and battery management functions onto a single die. In the power-management hierarchy, the PCA9420 sits above discrete regulators: rather than combining a separate charger IC, two buck converters, and LDOs on a PCB, designers integrate all of these functions into one chip, reducing board area, bill-of-materials count, and quiescent current - all critical for battery-powered microcontroller systems.
Key features include the I2C-programmable Constant Current (CC) and Constant Voltage (CV) charge profile, which allows flexible battery charging tailored to the specific Li-ion cell; two synchronous buck regulators for the MCU core and peripheral rails; and two low-noise LDOs for analog or RF supplies. Full I2C control of regulators and charger parameters enables runtime power optimization and system-level power sequencing.
Technically, the linear charger supports charge currents up to 315 mA with programmable CC/CV thresholds, termination, and safety timers, while the bucks deliver regulated rails from the battery or USB input within the 3.3V to 5.5V range. The PMIC targets operation up to 85C ambient per distributor data. Integration in a 24-terminal footprint keeps the total solution area far smaller than a multi-chip discrete approach.
Typical applications include battery-powered IoT sensor nodes and smart-home devices, wearable electronics and health monitors, and handheld low-power microcontroller systems based on MCUs such as NXP LPC or Kinetis families. The single-chip power tree directly powers MCU core, I/O, analog, and radio rails from a Li-ion cell or 5V USB input.
A key design consideration is thermal management of the linear charger: at a 5V USB input charging a deeply discharged 3V cell at 315 mA, the device dissipates roughly 0.6W, so PCB copper area under the exposed pad matters.
This page synthesizes distributor pricing tiers, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet, with prices as of 2026-09-14.
Drop-in alternatives for PCA9420 — 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:
PCA9420BSAZ
✅ Drop-In✓ In Stock
$1.53 / Unit
View Datasheet →PCA9420UKZ
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →PCA9421BS
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PCA9421UK
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PCA9420 Specifications
| Function | Power Management IC (PMIC): 2 buck + 2 LDO + linear Li-ion charger |
| Input Voltage Range | 3.3 V to 5.5 V |
| Maximum Charge Current | 315 mA (linear charger) |
| Charger Control | I2C programmable CC and CV values |
| Battery Chemistry | Li-ion / Li-Po (single cell) |
| Number of Buck Regulators | 2 |
| Number of LDO Regulators | 2 |
| Control Interface | I2C |
| Number of Circuits | 1 |
| Terminals | 24 |
| Operating Temperature | up to 85 C (max operating, per distributor data) |
| Mounting Type | Surface Mount |
| Applications | Low-power microcontroller applications powered by Li-ion battery |
| Package | 24-terminal (HVQFN-24 (BS) / WLCSP-24 (UK) variants) |
| RoHS Status | Compliant |
PCA9420 24-terminal (hvqfn-24 (bs) / wlcsp-24 (uk) variants) Pin Configuration Guide
Pin configuration for PCA9420 (24-terminal (hvqfn-24 (bs) / wlcsp-24 (uk) variants) 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 PCA9420.
Refer to the datasheet for full pin configuration.
Typical Applications
PCA9420 is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, Wearable Electronics, Handheld and Portable MCU Systems, Smart Home Devices, Health Monitoring Devices, Li-ion Accessory Charging Ports.
Battery-Powered IoT Sensor Nodes
IoT sensor nodes powered by a single Li-ion cell need a compact power tree that charges from USB or a solar/inductive input and then generates several regulated rails. The PCA9420 fits this need exactly: its linear charger handles up to 315 mA from the 3.3V to 5.5V input with I2C-programmable CC/CV values, while the two buck regulators supply the MCU core and radio at high efficiency and the two LDOs provide clean rails for analog sensors. Because everything is integrated in a 24-terminal package, node PCB area shrinks versus a discrete charger-plus-regulator design, and firmware can throttle rails over I2C to extend battery life during sleep-dominated duty cycles.
Recommended
Wearable Electronics
Wearables combine a small Li-Po cell, a low-power MCU, sensors, and often a wireless radio on a very small PCB, making board area the scarcest resource. The PCA9420 addresses this by merging the 315 mA charger, two bucks, and two LDOs into one 24-terminal device, eliminating three or more discrete ICs. The I2C-programmable charger lets the same hardware support different cell capacities across product SKUs, and the LDOs supply low-noise power to heart-rate or motion sensors where switching ripple would corrupt readings. Thermal dissipation of the linear charger stays manageable because wearable charge currents are typically capped well below the 315 mA maximum via register settings.
Recommended
Handheld and Portable MCU Systems
Handheld instruments, remotes, and portable diagnostic tools run from a Li-ion pack charged over USB 5V. The PCA9420's 3.3V to 5.5V input range accepts USB directly while its charger manages the cell, and its two buck regulators efficiently derive the 3.3V I/O rail and a lower core rail for MCUs such as the NXP LPC family. The two LDOs feed analog front ends and display bias with low noise. Firmware control over I2C enables graceful shutdown, battery-status monitoring, and charging parameter updates in the field, which is valuable for products with long service lives and multiple battery vendors.
Recommended
Smart Home Devices
Battery-backed smart home products - door locks, sensors, remotes, and hubs - require a power subsystem that charges a Li-ion cell from a wall adapter or USB and generates multiple low-power rails. The PCA9420 provides the full chain: a 315 mA linear charger with programmable CC/CV, two bucks for the MCU and wireless module, and two LDOs for sensitive circuits. Its integration reduces component count in cost-sensitive consumer hardware, and the I2C interface lets the host MCU place rails into low-power states between wake events. The 85C maximum operating temperature comfortably covers typical indoor smart home environments.
Recommended
Health Monitoring Devices
Consumer and clinical-adjacent health monitors - pulse oximeters, glucose meters, ECG patches - are battery powered and noise sensitive. The PCA9420's two LDOs provide quiet supply rails for the analog front end where switching regulator ripple would degrade measurement resolution, while the bucks efficiently power the digital core, extending battery run time between the 315 mA charge cycles. The I2C-programmable charger adapts to the small cells typical of medical wearables, and full firmware control supports charge safety management. Integration in a 24-terminal package helps meet the stringent size and weight limits of body-worn form factors.
Recommended
Li-ion Accessory Charging Ports
Accessory products such as true-wireless earbud cases, styluses, and small chargers use a Li-ion cell charged from USB and distribute power onward. The PCA9420 integrates the 315 mA linear charger with I2C-adjustable CC/CV thresholds for cell protection, plus two bucks and two LDOs to power Bluetooth SoCs and status indicators. The single-chip solution reduces the accessory PCB to essentially PMIC, cell, and radio, lowering cost in high-volume consumer categories. Designers should budget copper under the exposed pad because linear charging from 5V into a partially discharged cell dissipates the difference as heat.
Recommended
Recommended Products Summary
Engineering reference data for PCA9420 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PCA9420BSAZ | PCA9420UKZ | PCA9421BS |
|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 24-terminal (HVQFN-24 / WLCSP-24 variants) | HVQFN-24 | WLCSP-24 | HVQFN-24 |
| Battery Charger | Linear Li-ion, up to 315 mA, I2C-programmable CC/CV | Same - 315 mA linear charger | Same - 315 mA linear charger | Reduced/absent charger function (family variant) |
| Buck Regulators | 2 | 2 | 2 | 2 |
| LDO Regulators | 2 | 2 | 2 | 2 |
| Control Interface | I2C | I2C | I2C | I2C |
| Target Application | Low-power MCU systems powered by Li-ion battery | Same | Same | Low-power MCU systems (non-charger variant) |
Key Differentiators
- Integrated 315 mA linear Li-ion charger with I2C-programmable CC/CV (vs PCA9421BS)
- Single-chip power tree reduces BOM versus discrete approach (vs Discrete charger + buck + LDO solution)
- Flexible hardware platform across battery variants (vs PCA9420UKZ vs PCA9420BSAZ)
Design Notes
The PCA9420 uses a linear charger, so charging power dissipation equals (VIN - VBAT) x ICHG. Estimated: at a 5.0V USB input charging a 3.0V deep-discharged cell at the full 315 mA, the device dissipates roughly 0.63W. Keep the charge current register setting conservative when the cell voltage is low, or implement firmware-based current taper as the cell charges. Provide solid copper area under the package exposed pad and use thermal vias to the ground plane, per the layout guidance in the NXP datasheet.
Place the charger input capacitor, battery capacitor, and buck regulator output capacitors as close to the PCA9420 terminals as possible, with short, wide traces to the ground plane. Route buck switching nodes away from the LDO outputs and the analog loads they feed, since the LDOs are there specifically to deliver low-noise rails. Use a star or plane-based ground referenced to the IC exposed pad. Follow the NXP datasheet layout example for the 24-terminal footprint of your specific suffix (HVQFN-24 vs WLCSP-24) because land patterns differ.
Do not rely on the PCA9420 charging above 315 mA - the linear charger is fixed to that maximum, and exceeding the thermal budget at high VIN-VBAT deltas triggers thermal regulation. Verify that your system input never exceeds the 5.5V maximum operating range; unregulated wall adapters can exceed this. Also note that PCA9420 and PCA9421 are not functionally identical - the charger feature set differs between family members, so confirm the ordering code early in design. Finally, confirm the register defaults in the NXP datasheet I2C map before first power-up.
Compliance Information
RoHS-compliant, lead-free versions are stocked by DigiKey (PCA9420UKZ) and Mouser (PCA9420BSAZ). Formal REACH and halogen-free declarations should be obtained from the NXP product page for the specific ordering code.
