ACT4751
40 V, 4.0 A CC/CV Step-Down DC/DC Converter with USB PD 3.0 PPS
Please use ACT4752 for new designs.
Key Features
- USB certified charger design available
- 50 mOhm integrated high-/low-side FETs
- 4.5 to 40 V operational input voltage
- 5 V bias, 350 mA buck converter
- Programmable output voltage by I2C from 3 to 24 V in 12.5 mV steps
- Programmable output current limit from 0 to 4 A in 256 step resolution
- Fixed-frequency current-mode control from 450 kHz to 2.25 MHz with external clock sync and a 100% duty operation
- Out of AM radio / spread-spectrum operation
- 20 mA AUX LDO programmable output voltage from 0.9 to 4.0 V
- I2C interface, fast-mode plus (Fm+, 1 MHz) with configurable address
- Protections: UVLO, OVP, UVP (Hiccup/Latch-off), OCP, TSD
Qorvo's ACT4751 is a programmable DC-to-DC buck converter with bias supply rails for microcontrollers or USB PD controllers. It supports a wide input voltage range from 4.5 to 40 V and uses a synchronous step-down (buck) voltage regulator architecture. It integrates both the high side and low side MOSFETS. These 50 mOhm RDSON transistors enable high efficiency to reduce power losses.
The product's main buck converter can be dynamically programed to an output voltage between 3 and 24 V in 12.5 mV steps via the I2C interface or analog feedback. It also can dynamically program output current between 0 and 4 A in 256 steps via the I2C interface in a constant-current (CC) operation mode. The main buck operates in a proprietary current mode control that supports external clock syncing for switching frequencies between 450 kHz and 2.25 MHz.
ACT4751 is a perfect solution for USB Power Delivery (PD) 3.0 and Programmable Power Supply (PPS) applications. The product integrates a 5 V / 350 mA mini-buck converter and a 20 mA AUX LDO to simplify application system designs. These rails can power up a controller and the 1.5 W VCONN line in active USB-C cables.
ACT4751 is available in a 32-pin 5mm x 5mm QFN package with a power optimized footprint and exposed pad for improved thermal performance.
Typical Applications
- USB PD 3.0 Charging Hubs
- Power Management for USB-C Power Rails
- Industrial SMPS for 24V Bus
- High Power LED Lighting
Product Categories
Application Categories
- Applications> Customer Premises Equipment
- Applications> Automotive> In-Vehicle Chargers / Adapters
- Applications> Consumer Goods & Electronics> Bluetooth Speakers
- Applications> Consumer Goods & Electronics> USB Charging Hubs
- Applications> Industrial> Robotics
- Applications> Renewables, Power & Lighting> Backup Power Systems / UPS Units
- Applications> Renewables, Power & Lighting> Solid-State Lighting
| Topology | Step-Down |
| Input Voltage(V) | 4.5 to 40 |
| Max Output Current(A) | 4.0 |
| Frequency(kHz) | 450 to 2,250 |
| USB PD 3.0 PPS Certification | Yes |
| Programmable Current Limit | Output |
| Auxiliary Power Rails | Mini-Buck: 350mA; LDO: 20mA |
| AEC-Q100 | No |
| Package Type | QFN, 32-pin |
| Package(mm) | 5 x 5 |
| RoHS | Yes |
| Lead Free | Yes |
| Halogen Free | Yes |
| ITAR Restricted | No |
| ECCN | EAR99 |
ACT4751-101-REF01 Reference Design
USB PD 3.0 Power Charging Hub 175W, 2x USB-A, 2x USB-C Power Hub with Cypress CCG3PA
(USB Test ID: 851)
See ACT4751-101-REF03 for a Fast Charger 80W design based on the same PCB.
Qorvo achieved qualification for a four port USB Power Hub with the ACT4751 and a PD controller from Cypress (CCG3PA).
The USB-C™ channels support 80W (20V / 4A) the USB-A™ channels are qualified with 7.5W, but can support up to 15W.
All design details and layout files can be downloaded here. Please contact your Qorvo representative to get additional support.
ACT4751-101-REF03 Reference Design
USB PD 3.0 PPS (Programmable Power Supply) 80W, 1x USB-C Charging Hub with Cypress CCG3PA
(USB Test ID: 1100)
See ACT4751-101-REF01 for a Charger 80W design based on the same PCB.
Qorvo achieved qualification for an 80W USB PD 3.0 PPS (Programmable Power Supply) reference design with the ACT4751 and a PD controller from Cypress (CCG3PA).
This USB-C™ channel supports programmable 80W output voltage and current.
Voltage programming range: 3V to 21V in 20mV steps
Current programming range: 1A to 4A in 50mA steps
All design details and layout files can be downloaded here. Please contact your Qorvo representative to get additional support.
Note: Per a limitation from testing resource, only one USB-C port is tested and certified on this design. This is not a limitation of ICs nor this board design.