Synchronous, Step-Down DC-to-DC Controller with Voltage Tracking and Synchronization
Features and Benefits
- Wide bias voltage range 3.0 V to 20 V
- Wide power stage input range 1 V to 24 V
- Wide output voltage range: 0.6 V to 85% of input voltage
- ±0.85% accuracy at 0°C to 70°C
- All N-channel MOSFET design for low cost
- Fixed-frequency operation at 300 kHz, 600 kHz, or resistor adjustable 300 kHz to 600 kHz
- Clock output for synchronizing other controllers
- No current sense resistor required
- Internal linear regulator
- Voltage tracking for sequencing
- Soft start and thermal overload protection
- Overvoltage and undervoltage power-good indicator
- 15 μA shutdown supply current
- Available in a 20-lead QSOP and 20-lead, 4mm × 4 mm LFCSP
The ADP1828 is a versatile and synchronous PWM voltage mode buck controller. It drives an all N-channel power stage to regulate an output voltage as low as 0.6 V to 85% of the input voltage and is sized to handle large MOSFETs for point-of-load regulators. The ADP1828 is ideal for a wide range of high power applications, such as DSP and processor core I/O power, and general-purpose power in telecommunications, medical imaging, PC, gaming, and industrial applications. It operates from input bias voltages of 3 V to 20 V with an internal LDO that generates a 5 V output for input bias voltages greater than 5.5 V.
The ADP1828 operates at a pin-selectable, fixed switching frequency of either 300 kHz or 600 kHz, or at any frequency between 300 kHz and 600 kHz with a resistor. The switching frequency can also be synchronized to an external clock up to 2× the part’s nominal oscillator frequency. The clock output can be used for synchronizing additional ADP1828s (or the ADP1829 controllers), thus eliminating the need for an external clock source. The ADP1828 includes soft start protection to limit any inrush current from the input supply during startup, reverse current protection during soft start for a precharged output, as well as a unique adjustable lossless current-limit scheme utilizing external MOSFET RDSON sensing.
For applications requiring power-supply sequencing, the ADP1828 provides a tracking input that allows the output voltage to track during startup, shutdown, and faults. The additional supervisory and control features include thermal overload, undervoltage lockout, and power good.
The ADP1828 operates over the −40°C to +125°C junction temperature range and is available in a 20-lead QSOP and 20- lead, 4mm × 4mm LFCSP.
- Telecom and networking systems
- Base station power
- Set-top boxes, game consoles
- Printers and copiers
- Medical imaging systems
- DSP and microprocessor core power supplies
- DDR termination
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
This describes the design, operation, and test results of the 20 A ADP1828 evaluation board and the ADP1828 5 A evaluation board.
The input range for the 20A evaluation board is 6 V to 18 V, and the output voltage is 1.8 V with a maximum load current of 20 A. For this design, a switching frequency (fSW) of 300 kHz is chosen to achieve a good balance between efficiency and the sizes of the power components.
The input range for the 5A evaluation board is 5.5 V to 13.2 V, and the output voltage is 1.8 V with a maximum load current of 5 A. For this design, a switching frequency (fSW) of 600 kHz is chosen to achieve a good balance between efficiency and the sizes of the power components.
Tools & Simulations
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Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.